Motor Starting e Tap

Motor Starting Analysis

Página 1 de 46

Motor Starting Analysis During the motor starting period, the starting motor appears to the system as a small impedance connected to a bus. It draws a large current from the system, about six times the motor rated current, which therefore results in voltage drops in the system and imposes disturbances to the normal operation of other system loads. Since the motor acceleration torque is dependent on motor terminal voltage, in some cases the starting motor may not be able to reach its rated speed due to extremely low terminal voltage. This makes it necessary to perform a motor starting analysis. The purpose of performing a motor starting study is twofold: to investigate whether the starting motor can be successfully started under the operating conditions, and to see if starting the motor will seriously impede the normal operation of other loads in the system. ETAP provides two types of motor starting calculations: Dynamic Motor Acceleration and Static Motor Starting. In the Dynamic Motor Acceleration calculation, the starting motors are represented by dynamic models and the M otor Acceleration module simulates the entire process of motor accelera tion. This method is used to determine if a motor can be started and how much time is needed for the motor to reach its rated speed, as well as to determine the effect of voltage dips on the system. In Static Motor Starting, the starting motors are modeled by the locked-rotor impedance during acceleration time, simulating the worst impact on normal operating loads. This method is suitable for checking the effect of motor starting on the system when the dynamic model is not available for sta rting motors. The Motor Starting Analysis Chapter is divided into the following Sections: The Motor Starting Toolbar Section explains how to start a motor starting calculation, to open and view an output report, and to select display options. The Motor Starting Study Case Editor Section explains how you can create a new study case, what parameters are required to specify a study case, and how to set the parameters. The Display Options Section explains available options for displaying some key system parameters and the output results on the one-line diagram. The Motor Starting Calculation Methods Section describes calculation methods used by the module. The Required Data for Calculations Section describes what data are necessary to perform motor starting studies and where to enter them. The last three Sections describe how to view calculation results.

Motor Starting Analysis Toolbars - Time Slider Toolbar Study Case Editor - Info Page - Event Page - Add Action by Starting Category - Add Action by Load - Model Page - Adjustment Page - Alert Page Display Options Motor Starting Plots - Plot Display Motor Starting Calculation M ethods - Motor Starting Required Data Motor Starting Output Reports One-Line Diagram Display Alert View

Motor Starting Toolbar

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 2 de 46

Run Dynamic Motor Starting Click this button to perform a time-domain simulation for starting and/or switching off motors and static loads. Accelerating motors are modeled dynamically for this study; therefore, related motor parameters such as dynamic model (or LR model for synchronous motors), inertia, and starting load must be specified. Motors (induction and synchronous) and static loads can be switched off and on in any event created.

Run Static Motor Starting Click this button to perform a tim e-domain simul ation for start ing and/ or swit ching off motors and static loads. For this study, starting motors are modeled as constant impedance loads calc ulated from their locked-rotor current s with a user-defined acceleration tim e. Required parameters for thi s st udy include the locked-rotor current and power fac tor, acceleration t ime at no-loa d and full-load, and st arti ng load.

Motors (induction and synchronous), MOVs, and static loads can be switched off and on in any event created.

Display Options Click this button to customize the information and results annotations displayed on the one-line diagram in Motor Starting mode.

Alert View Click this button to bring up Motor Starting Analysis Alert View, which lists all critical and marginal alerts for a study based on the set up in the Alert page of the study case used.

Report Manager Motor acceleration output reports are provided in Crystal Reports. The Report M anager provides four pages (Complete, Input, Result, and Summary) for viewing the different parts of the output report for both text and Crystal Reports. Available formats for Crystal Reports are displayed in each page of the Report Manager for motor starting (dynamic and static) studies.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 3 de 46

Crystal Reports formatted reporting is activated by choosing a format in the Report Manager. You can open the whole study output report or only a part of it, depending on the format selection. You can view the report in the Crystal R eports viewer, or save the report in PDF, MS Word, Rich Text Format, or Excel format. If you wish this sele ction to be the default for reports, click the Set As Default check box. You can also view output reports by cl icki ng the Output Report button on the Study Case toolbar. A l ist of all out put fil es in the selected proj ect directory is provi ded for m otor start ing calcul ations. To view any of the listed output reports, click the out put report nam e, and then click the List Output Report button.

Motor Starting Plots To view plots of accelerated motors, click this button to bring up a dialog box to select motors from a dropdown list.

Halt Current Calculation The Stop Sign button is normally disabled. When a motor acceleration calculation has been initiated, this button becomes enabled and shows a red stop sign. Clicking this button will terminate the current calculation. One-line diagram display will not be available if you terminate the calculation before it completes; but the output report and plots do store the calculation results up to the time when you terminate the calculation.

Get On-Line Data This button is active when the ETAP Real-Time Advanced Monitoring is online. C lick on this button to use real time data as initial conditions for this analysis.

Get Archived Data This button is active when the ETAP Real-Time Event Playback is online. Click on this button to use archived data as initial conditions for this analysis.

Motor Starting Analysis Toolbars - Time Slider Toolbar Study Case Editor - Info Page - Event Page - Add Action by Starting Category - Add Action by Load - Model Page - Adjustment Page - Alert Page Display Options Motor Starting Plots - Plot Display Motor Starting Calculation M ethods - Motor Starting Required Data Motor Starting Output Reports One-Line Diagram Display Alert View

Time Slider Toolbar Motor Starting Time-Slider Once a motor starting study is completed, the Motor Starting Time-Slider, as shown below, will appear next to the Configuration & Mode Toolbar. The slider ranges from zero to the total simulation time. Initially, the reference pointer is at the far left, corresponding to t = 0 seconds. You may click on either end of the ruler to move the pointer one grid at a time, or hold the mouse button down to move the pointer continuously. You may also click on the pointer, hold the mouse button down, then drag the pointer to the

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 4 de 46

desired position. The time corresponding to the pointer position is also displayed next to the ruler in units of seconds. As you move the pointer along the slider, the displayed results change accordingly, providing you with a quick way to examine the calculation results.

Motor Starting Analysis Toolbars - Time Slider Toolbar Study Case Editor - Info Page - Event Page - Add Action by Starting Category - Add Action by Load - Model Page - Adjustment Page - Alert Page Display Options Motor Starting Plots - Plot Display Motor Starting Calculation M ethods - Motor Starting Required Data Motor Starting Output Reports One-Line Diagram Display Alert View

Study Case Editor - Motor Starting Analysis The Motor Starting Study Case editor contains solution control variables, prestart loading conditions, motor starting events, and a variety of options for output reports. The study case is used for both dynamic and static motor acceleration studies. ETAP allows you to create and save an unlimited number of study cases. Motor starting calculations are conducted and reported in accordance with the settings of the study case selected in the toolbar. You can switch between study cases without resetting the options each time. This feature is designed to organize your study efforts and save you time. As part of the multi-dimension database concept of ETAP, study cases can be used for any combination of the three major system toolbar components (configuration status, one-line diagram presentation, and Base/Revision Data). The Motor Starting Study Case editor can be accessed by first selecting the Motor Starting Analysis Mode from the Status/M ode toolbar, then c licking the Study Case button from the M otor Starting toolbar. You can also access this editor from the Project View by clicking the Motor Starting Study Case folder. To create a new study case, go to the Project View, right-click the Motor Starting Study Case folder, and select Create New. The Motor Acceleration module will then create a new study case, which is a copy of the default study case, and adds it to the M otor Starting Study Case folder.

Motor Starting Analysis Toolbars - Time Slider Toolbar Study Case Editor - Info Page - Event Page

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 5 de 46

- Add Action by Starting Category - Add Action by Load - Model Page - Adjustment Page - Alert Page Display Options Motor Starting Plots - Plot Display Motor Starting Calculation M ethods - Motor Starting Required Data Motor Starting Output Reports One-Line Diagram Display Alert View

Info Page - Motor Starting Study Case Editor

Study Case ID Study case ID is shown in this entry field. You can rename a study case by deleting the old ID and entering the new ID. The study case ID can be up to 12 alphanumeric characters in length. Use the Navigator button at the bottom of the editor to go from one study case to the next existing study case.

Solution Parameters In this group you can select a load flow solution method. Two methods are available: Newton-Raphson,

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 6 de 46

and Adaptive Newton-Raphson. Choose solution control values for the load flow and motor starting solutions as well as the plot resolution.

Max. Iteration This value determines the maximum number of iterations ETAP can make while solving the load flow equations. This means that the load flow should quit if it has not converged after the number of iterations you specify here. Since dynamic and static motor starting calculation methods use the Newton-Raphson algorithm, typical systems are solved within two to three iterations. We recommend choosing a minimum of five iterations. If the solution does not converge, you may want to increase this number, as well as decrease the value you have specified for precision.

Precision The load flow algorithm works by an iterating procedure until the motor loads it calculates for each bus match the motor loads which are scheduled for each bus. The difference is called system mismatch. Solution Precision tells ETAP how many mismatches are allowed for a solution to be considered valid. When the mismatch for the motor MW and Mvar on each individual bus is below the value you enter for precision, ETAP halts the load flow solution and declares that the solution has converged. Try using a value of 0.001 to begin. If your system will not converge, try increasing this value incrementally (for example, to 0.005, etc.) until it converges.

Simulation Time Step Enter the simulation time step for motor starting calculations. The recommended simulation time step is 0.001 second. If the simulation time step is too small, accumulation of the round off errors can cause inaccurate results. On the other hand, if this value is too large, calculation results may not capture the dynamic characteristics corresponding to very small time constants of the control equipment or system.

Plot Time Step This value determines how often ETAP should record the results of the simulation for plotting. For instance, if you specify 20 steps, ETAP will plot points at every 20 X simulation time step (for example, for a simulation time step of 0.001 plot time step will be .02 seconds). The smaller this number is, the smoother your plots will look, but also remember that the plot files on your hard disk may grow quite large. The main thing to keep in mind is that ETAP records plot information at this interval throughout the simulation. So if you specified a simulation time step of 0.001 seconds, plot time step of 10, and a total time of 20 seconds, ETAP will write 20/(0.001*10)= 2000 points to disk, which is a large plot file.

Apply XFMR Phase-Shift Select this option to consider transformer phase-shift in load flow calculations. The phase-shift of a transformer can be found in the Transformer Editor.

Prestart Loading Category This option allows you to specify how the system is loaded prior to starting any motors and/or switching on any static loads. You can select presta rting loads by loading categories or from operating load.

Loading Category Select one of the ten loading categories for prestart loading in the motor starting study case. With the selection of any category, ETAP uses the percent loading of all motors and other loads as specified for that category. Note: You can assign loading to each one of the ten categories from the Nameplate page of the M otor editors and the Loading page of the Static Load editors.

Operating P, Q This option is enabled only if your installation of ETAP has the on-line feature (Real-Time module). When this option is selected, the operating load will be used as the prestart load instead of the loading category.

Prestart Generation Category This option allows you to specify how the generators and power grids are operating prior to starting any motors and/or switching on any static loads. You can select prestarting generation by generation categories

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 7 de 46

or from operating values.

Generation Category Select one of the 10 generation categories for prestart generation. With the selection of any category, ETAP uses the generation values as specified for that category in the Rating page of a generator or a power grid. Depending on the operating mode of the source, the generation values may include voltage magnitude and angle, real and reactive power, or power factor.

Operating P, Q, V When this option is selected, the operating values will be used as the prestart generation instead of the generation category. Note: The operating values for a generator or a power grid can be entered from the Rating page of its editor or be updated automatically from a load flow calculation.

Prestart Charger Loading This group allows you to select the charger loading source.

Loading Category When this option is selected, the load from the category specified in the Category field will be used to calculate the charger load for the prestarting load flow.

Operating Load When this option is selected, the charger operating load will be used for the prestarting load flow. Note: The charger operating load is updated from DC load flow studies when the Updating Charger Load option has been selected in the DC Load Flow Study Case.

Load Diversity Factor This group allows you to specify load diversity factors to be applied on the loading category load. When the Operating Load is selected, no diversity factor is considered.

None Select this option to use the percent loading of each load as entered for the selected Loading Category.

Bus Maximum When this option is selected, all motors and other loads directly connected to each bus will be multiplied by the bus maximum diversity factor. Using this option, you can simulate load flow studies with each bus having a different maximum diversity factor. This study option is helpful when the future loading of the electrical system has to be considered a nd each bus may be loaded at a different maximum value.

Bus Minimum When this option is selected, all motors and other loads directly connected to each bus will be multiplied by the bus minimum diversity factor. Using this option, you can simulate load flow studies with each bus having a different minimum diversity factor.

Global Enter the diversity factors for all constant kVA, constant Z, constant I, and Generic loads. When you select this option, ETAP will globally multiply all loads of the selected category with the entered load diversity factors according to load types. Note: A motor load-multiplying factor of 125% implies that the motor loads of all buses are increased by 25 percent above their nominal values. This value can be smaller or greater than 100 percent.

Report

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 8 de 46

Bus Voltage in Percent Prints Calculated bus voltages in the output report as a percentage of the bus nominal voltages. For information about graphical display of bus voltages, see Section 21.3, Display Options.

Bus Voltage in kV Prints Calculated bus voltages in the output report in kV. For information about graphical display of bus voltages, see Section 21.3, Display Options.

Skip Tabulated Plots Check to skip generating tabulated plots for the output report. This will significantly reduce calculation time.

Study Remarks You can enter up to 120 alphanumeric characters in this remark box. Information entered here will be printed on the second line of every output report page header. These remarks can provide specific information regarding each study case. Note: The first line of the header information is global for all study cases and entered in the Project Information Editor.

Motor Starting Analysis Toolbars - Time Slider Toolbar Study Case Editor - Info Page - Event Page - Add Action by Starting Category - Add Action by Load - Model Page - Adjustment Page - Alert Page Display Options Motor Starting Plots - Plot Display Motor Starting Calculation M ethods - Motor Starting Required Data Motor Starting Output Reports One-Line Diagram Display Alert View

Time Event Page - Motor Starting Study Case Editor ETAP allows you to set up unlimited number of events to simulate switching actions in a single Motor Starting simulation. You can start or switch off individual loads or categorized motor groups with the Action by Load and Action by Starting Category features, respectively. You can also change the operating load by clicking the Load Transitioning option to change from one loading category to another.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 9 de 46

You can start or switch off multiple loads by starting category and/or by individual load. Note: The Motor Acceleration module assumes that all In Service loads are operating, except for the loads that are started or switched off in time events. If you start an already running load, ETAP will ignore the second starting action. If you switch off an already switched off load, ETAP will ignore the second switch off action. Note: You can specify conflicting actions on a motor during the same time event by using the Action by Starting Category and Action by Load options. In such an event, the M otor Acceleration module checks the action specified by Action by Load first, and then checks the Action by Category event. The first valid action gets executed in the simulation and the rest are ignored.

Events The Events Group lists all the events you specified in the study case according to their time of occurrence. The active events are flagged by a “*” sign and are listed before inactive events. In the calculation, only active events are simulated. For each event, it displays the event name and the time of occurrence. When you click an event from the list, all the actions defined for the event are displayed in the other groups on the page. You may Add, Edit or Delete an event by clicking the corresponding buttons.

Add When you click the Add button, it brings up the Event Editor for you to add a new event. Active Select this option to activate the event. When an event is inactive, it will not be considered in the motor

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 10 de 46

starting calculations.

Event ID Enter a name for the event. It can be an alphanumeric string up to 12 characters. This name does not have to be unique, but it is suggested to use a unique name for each event within a give study case.

Time Enter the time for each time event in seconds. Note: ETAP lists events in the order of the time defined here.

Edit When you click the Edit button while an event is selected from the Events list, it brings up the Event Editor with all the information for the event for you to modify. For description of the Event Editor, see the Add Section above.

Delete When you click the Delete button while an event is selected from the Events list, it removes the events and associated actions from the study case. Note: All changes, including removing an event, will not take effect until you click the OK button or navigate to another study ca se.

Total Simulation Time Total Simulation Time is the amount of time, in seconds, that you want the simulation to run. For instance, let's say you set up the following scenario: t1 = 0.00 Nothing happens during this time event t2 = 0.10 Start motor Mtr10 and switch on static load Stat2 on bus 20 t3 = 0.20 Switch off M tr8 on bus 10 Total Simulation Time = 2.00 This simulation will go as follows: at time t1 = 0, ETAP will run a load flow, using the prestart loading you selected, to find the initial conditions of the system. At time t2 = 0.1 seconds, ETAP will begin accelerating motor Mtr10 and switch on static load Stat2 on bus 20. At time t3 = 0.2 seconds, ETAP will switch off the motor Mtr8 on bus 10. The simulation will continue for 1.8 more seconds, until time T = 2.0 seconds, when the simulation ends and the plots and summary reports are generate d. As you can see, the total time must be greater than your last event time.

Action by Element This feature allows you to switch on/off any existing motor or static load or change generation category of a generator/power grid in a time event. The list of loads and sources that have been selected is displayed in the Action by Load list box.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 11 de 46

Add To add a switching action for a motor, MOV, static load, generator, or power grid, click the Add button to open the Add Action By Element editor. This editor allows you to add and/or modify a motor, MOV, static load, generator, or power grid specifications, such as start/switch off, starting categories and generation categories. Click the OK button and the specifications of the selected elements will be displayed in the Action by Element list box.

Element Type Motor Starting studies simulate switching of three types of loads: induction/synchronous motor, static load and capacitor, and M OV. ETAP also simulates change of generation category for a generator or a power grid.

Action Select this option to switch/stop motor, switch on/off a static load or a capacitor, start an MOV, or change generation category for a generator or a power grid. If you start an already running load, ETAP will ignore the second starting action. If you switch off an already switched off load, ETAP will ignore the second switch off action. Note: ETAP assumes that all In Service loads are operating, except for the loads that are started or switched off in time events. Motor, Load, MOV, Generator

ID Select an element ID from the drop-down list. The content in this list varies according to element type selected. For motor load, it contains all induction and synchronous motors; for static load, it contains all static loads and capacitors; for MOV, it contains all the M OVs; and for Gen/Power Grid, it contains all the

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 12 de 46

generator and power grids in the system.

Starting Category When M otor is selected from Element Type, this field shows up for you to specify a predefined starting category from the list box. This list box contains all ten motor starting categories. Information for starting categories can be defined in the Start Cat page of Induction and Synchronous Motor editors, including starting and final loading percent, as well as begin and end time of load change. When starting a motor by element, you do not need to select the Starting Category option to use the loading and time data defined for the starting category. Note: The starting category is not applicable to static loads.

Loading Category When Static Load is selected from Element Type and the selected action is Switch On, this field shows up for you to specify a predefined loading category from the drop-down list. This list contains all ten loading categories. The loading percent of the specified loading category, as defined in the Loading page of Static Load Editor, will be used to determine the amount of load to be switched on.

Generation Category When Gen/Power Grid is selected from Element Type, this field shows up for you to specify a predefined generation category from the list box. This list box contains all ten generation categories. The generator/power grid operating data from the selected category, as defined in the Rating page of Synchronous Generator Editor or Power Grid Editor, will be used to simulate its operating condition.

Edit To edit an action, click its action item and then click the Edit button. The Edit button opens the Edit Action By Element editor. This editor allows you to modify the data. The options in this editor are the same as those for the Add Action by Element editor. For information about the Add Action by Element editor, see the Add Section above.

Delete To delete an action from the Action by Element list, select the element by clicking its action item and then click the Delete button. The selected load will be removed from the action list.

Action by Starting Category This feature allows you to start motors by predefined motor starting categories. Note: Motor starting categories can be defined in the Start Cat page of the Induction Motor, Synchronous Motor, and MOV editors. The selected motor groups are displayed in the Action by Starting Category list box.

Add To start or switch off a predefined group of motors, click on the Add button to open the Add Action By Starting Category editor. This editor allows you to add and/or modify motor group specifications, such as start/switch off, starting categories, and connected bus IDs. Click the OK button and the specifications of the motor groups selected in this editor will be displayed in the Action by Starting Category list box.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 13 de 46

Action Select Start or Switch Off for the selected motor group. If you start an already running load, ETAP will ignore the second starting action. If you switch off an already switched off load, ETAP will ignore the second switch off action. Note: ETAP assumes that all In Service loads are operating, except for the loads that are started in time events.

By Category Starting Category Select a predefined starting category from the list box. This list box contains all ten motor starting categories. M otor starting categories can be defined in the Start Cat page of Induction and Synchronous Motor editors.

Bus ID Select a bus ID to define the motor starting group from the drop-down list. This list contains all bus IDs created for the electrical system under study. In addition, you can choose Start or Switch Off for all buses defined by a starting category by selecting All B uses from the Bus ID list.

Edit To edit a selected group of motors, click its action item and then click the Edit button. The Edit button opens the Add Action By Starting Category editor. This editor allows you to modify the data. For information about the Add Action by Element editor, see the Add Section above.

Delete To delete a motor group from the Action by Starting Category listing, select the motor group by clicking its action item, and then click the Delete button. The selected motor group will be removed from the action list.

Action by Load Transitioning This feature allows you to change operating load from one loading category to another. In changing the loading category, if a motor load is changed from a zero percent to a non-zero percent load, it will create an action to start the motor. However, once a motor is started by an action from Load Transition, the Load Transition option will not a pply to the motor anymore. Furthermore, once a load, including motors, static loads, and capacitors, has been switched on or off through Action by Load or Action by Starting C ategory, the Load Transition option will not apply to this load from that point on.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 14 de 46

Active Select this option to activate load transitioning in this event.

Loading Category Select a new loading category from the list.

Exclude MV Load >= Select this option to enable the kVA field on the right. Enter the kVA limit in the field for medium voltage loads to be ignored in the Load Transition. If this option is cleared, medium voltage loads of all sizes will be considered in the Load Transition. Loads with rated voltage higher than 1 kV are considered as medium voltage loads.

Exclude LV Load >= Select this option to enable the kVA field on the right. Enter the kVA limit in the field for low voltage loads to be ignored in the Load Transition. If this option is cleared, low voltage loads of all sizes will be considered in the Load Transition. Loads with rated voltage not higher than 1 kV are considered as low voltage loads.

kVA Once enabled, you can enter a limit for load capacity rating in this text box. Note: A value of zero means that no loads are considered in the Load Transition.

Motor Starting Analysis Toolbars - Time Slider Toolbar Study Case Editor - Info Page - Event Page - Add Action by Starting Category - Add Action by Load - Model Page - Adjustme nt Page - Alert Page Display Options Motor Starting Plots - Plot Display Motor Starting Calculation M ethods - Motor Starting Required Data Motor Starting Output Reports One-Line Diagram Display Alert View

Model Page – Motor Starting Study Case Editor In the Model Page specify model information for transformer LTCs and motor loads.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 15 de 46

Transformer LTC Include Automatic Action In this group you can specify the transformer LTC feature to be simulated in motor starting studies. For Prestart Load Flow If this option is selected, automatic voltage regulation actions and LTCs of transformers, if there are any, will be simulated in the prestart load flow calculation. During & After Motor Acceleration If this option is selected, LTC s of transformers, if there are any, will be simulated in calculations after the prestart load flow.

Time Delay During motor starting, the Motor Acceleration module will check the voltages of the LTC regulated buses and set up an internal clock with a time delay. If a voltage is out-of-range and stays out-of-range, at the end of the initial delay time (Ti), the module will check the voltage again and decide whether to reset the clock or initiate an LTC tap adjustment. In the latter case, it will take a time duration equal to the operating time (Tc) to complete the LTC tap change. This process will continue until the final voltage falls within the regulating range or the LTC has reached its limits. In this group you specify the LTC time delay used in the calculation. The information in this group is applied in the study only when the During & After Motor Acceleration option is selected. Use Individual LTC Time Delay If this option is selected, the initial time delay and the operating time entered in the individual transformer editor will be used in the calculation.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 16 de 46

Use Global Time Delay When this option is selected, the values entered in the Initial Time Delay and Operating Time fields will be used in the calculation. This means that all of the LTCs in the system will assume the same initial time delay and operating time. Initial Time Delay In this field you can enter the global initial time delay in seconds. Operating Time In this field you can enter the operating time in seconds.

Starting Load of Accelerating Motors In the motor acceleration calculations, the difference between the motor torque and the load torque changes the motor speed. In ETAP, the load torque model is specified as torque in percent as a function of normalized motor speed. This load torque may be based on motor electrical rating or on mechanical load. In this group, you indicate to the Motor Acceleration module which base you want to use.

Based on Motor Electrical Rating When this option is selected, it is assumed that the load torque model you selected in the M otor editor only represents the shape of the load as a function of speed. The load torque values will be adjusted so that at the synchronous speed the torque is equal to 100%. This means that, with the modified load curve, the motor will consume the rated electrical power at 100% starting load, under the rated voltage and at the rated speed. When this option is selec ted, the torque base used to construct load torque model has no effect on calculation results.

Based on Motor Mechanical Load When this option is selected, it is assumed that the load torque model you selected in the Motor editor represents the actual load based on rated output torque. The load curve will be applied as it is without any adjustments. To illustrate the implication of this selection, consider a motor that has a start load of 50% and rated output torque Tr. On the Load page of the motor, the load torque curve is M odel 1 given below, which has a load torque of 80% at operating speed and the curve is based on Tr.

Motor Load Model Curves

Model 1: Load @ Rated Speed < 100% Model 2: Load @ Rated Speed = 100% Case 1: Load Model Based on Motor Electrical Loading In this case, the load torque curve will be shifted so that the torque at rated speed is 100% of the motor rated torque. This means that the torque at each point on the load curve will be multiplied by a factor of 1.25 (equal to 1/0.8). This modified the curve will be used as the load torque curve for the study. Note that the modified curve is given as Model 2 above. Since the starting load is 50%, the actual load will be 50% of the load based on the modified curve (Model

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 17 de 46

2) as described above. The starting load torque is equal to 0.5 Tr. Case 2: Load Model Based on Motor Mechanical Load In this case, the load torque curve will not be shifted because it is assumed to represent the actual load. However, since the starting load is 50%, the load torque curve will be adjusted so that the torque at each point of the curve is multiplied by 0.5. The starting load torque is equal to 0.5*0.8 Tr = 0.4 Tr. Note: If the motor has a load model as given in Model 2 above, there is no difference in calculation results between the two options.

Motor Starting Analysis Toolbars - Time Slider Toolbar Study Case Editor - Info Page - Event Page - Add Action by Starting Category - Add Action by Load - Model Page - Adjustment Page - Alert Page Display Options Motor Starting Plots - Plot Display Motor Starting Calculation M ethods - Motor Starting Required Data Motor Starting Output Reports One-Line Diagram Display Alert View

Adjustment Page - Motor Starting Study Case Editor This page allows the User to specify tolerance adjustments to transformer, reactor, and overload heater impedance, cable and transmission line length, and cable and transmission line temperature effect on their resistance values. Each tolerance adjustment can be applied based on the individual equipment percent tolerance setting or based on a globally specified percent value.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 18 de 46

Impedance Tolerance In this group, you can specify impedance tolerance values for transformer, reactor, and overload heater.

Transformer This adjustment is applied to transformer impedance. The net effect of the transformer impedance adjustment in motor starting calculations is to increase the impedance by the specified percent tolerance value. For example, if the transformer impedance is 12% and the tolerance is 10%, the adjusted impedance used in the motor starting calculation will be 13.2%, resulting in higher losses. The Impedance Adjustment can be applied to individual transformers by using the tolera nce percent value specified in the Transformer editor Rating page. Alternatively, a global Transformer Impedance Adjustment can be applied as well by selecting and specifying a global tolerance other than 0% in the corresponding field.

Reactor This adjustment is applied to the reactor impedance. The Motor Starting module increases the reactor impedance by the specified percent tolerance resulting in a larger impedance value and consequently a larger voltage drop. For example, if the impedance of the reactor is 0.1 Ohm and its tolerance is 5%, then the adjusted reactor impedance used in the Load Flow calculation is 0.105 Ohm. The Impedance Adjustment can be applied to individual reactors by using the tolerance percent value specified in the Reactor editor Rating page. Alternatively, a global Reactor Impedance Adjustment can be applied as well by selecting and specifying a global tolerance other than 0% in the corresponding.

Overload Heater This adjustment is applied to the overload heater (OH) resistance. The M otor Starting module increases the OH resistance by the specified percent tolerance resulting in a larger resistance and consequently a larger

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 19 de 46

voltage drop. For example, if the resistance of the OH is 0.1 Ohm and its tolerance is 5%, then the adjusted OH resistance used in the motor starting calculation is 0.105 Ohm. The Resistance Adjustment can be applied to individual overload heaters by using the tolerance percent value specified in the Overload Heaters editor R ating page. Alternatively, a global Overload Heater Resistance Adjustment can be applied as well by selecting and specifying a global tolerance other than 0% in the corresponding field.

Length Tolerance You can specify length tolerance values for cables and transmission lines in this group. If Ohms is selected as the unit for a cable in the Impedance page of Cable editor, the length tolerance will not be applied to the cable. Likewise,if Ohms is selected as the unit for a transmission line in the Impedance page of Transmission editor, the length tolerance will not be applied to the transmission line.

Cable This adjustment is applied to the cable length. The Motor Starting module increases the cable length by the specified percent tolerance resulting in larger impedance and consequently a larger voltage drop. For example, if the length of the cable is 200 ft. and the tolerance is 5%, then the adjusted cable length used in the motor starting calculation is 210 ft. The Length Adjustment can be applied to individual cables by using the tolerance percent value specified in the Cable editor Info page. Alternatively, a global Cable Length Adjustment can be applied as well by selecting and specifying a global tolerance other than 0% in the corresponding.

Transmission Line This adjustment is applied to the transmission line length. The Motor Starting module increases the transmission line length by the specified percent tolerance resulting in larger impedance and consequently a larger voltage drop. For example, if the length of the transmission line is 2 miles and the tolerance is 2.5%, then the adjusted transmission line length used in the motor starting calculation is 2.05 miles. The Length Adjustment can be applied to individual lines by using the toleranc e percent value specified in the Transmission Line editor Info page. Alternatively, a global Transmission Line Length Adjustment can be applied as well by selecting and specifying a global tolerance other than 0% in the corresponding field.

Resistance Temperature Correction This group allows the User to consider resistance correction based on the maximum operating temperature for cable and transmission line conductors. Each temperature resistance correction can be applied based on the individual cable/line maximum temperature setting or based on a globally specified value.

Cable This adjustment is applied to the cable conductor resistance. The M otor Starting module adjusts the conductor resistance based on the maximum operating temperature. If the maximum operating temperature is greater than the rated base temperature of the conductor, then its resistance is increased. The temperature correction can be applied to individual cables by using the maximum operating temperature value specified in the Cable editor Impedance page. A global temperature correction can be specified as well by selecting and specifying a global maximum temperature value in the corresponding field. For more information, see the Cable Editor Impedance Page Section in Chapter 11, AC-Editors.

Transmission Line This adjustment is applied to the transmission line conductor resistance. The M otor Starting module adjusts the conductor resistance based on the maximum operating temperature. If the maximum operating temperature is greater than the rated base temperature of the conductor, then the resistance is increased. The temperature correction can be applied to individual lines by using the maximum operating temperature value specified in the Transmission Line editor Impedance page. A global temperature correction can be specified as well by selecting and specifying a global maximum temperature value in the corresponding. For more information, see the Transmission Line Editor Impedance Page Section in Chapter 11, AC-

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 20 de 46

Editors.

Motor Starting Analysis Toolbars - Time Slider Toolbar Study Case Editor - Info Page - Event Page - Add Action by Starting Category - Add Action by Load - Model Page - Adjustment Page - Alert Page Display Options Motor Starting Plots - Plot Display Motor Starting Calculation M ethods - Motor Starting Required Data Motor Starting Output Reports One-Line Diagram Display Alert View

Alert Page - Motor Starting Study Case Editor You can specify the limits for ETAP to raise critical and marginal alerts for a Motor Starting simulation from the Alert page. The a lerts consist of three categories: alerts on starting motor and MOV, alerts on generator operating conditions, and alerts on bus voltage. Each category also consists of several types. Select an alert type to have ETAP perform an alert check for that type. If an alert type is not selected, ETAP will skip the alert check for tha t alert type.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 21 de 46

Critical and Marginal There are two levels of alerts for a M otor Starting study: critical alert and marginal alert. The alert limit values are set in the Critical and M arginal columns. The difference between Marginal and Critical Alerts is their use of different percent value conditions to determine if an alert should be generated. If a condition for a Critical alert is met, an alert will be generated in the Critical Alert group of the Alert View window. The same is true for M arginal Alerts. Also, the M arginal Alerts option must be selected to display the Marginal Alerts. If a device alert qualifies it for both Critical and Marginal alerts, only Critical Alerts are displayed. Note : For ETAP to generate alerts for an element type, both the element rating and the percent value entered in this page must be non-zero. The element ratings for alert checking are given in the following Sections.

Starting Motor/MOV ETAP checks alert for motor terminal voltage and fail to start for starting motors and M OVs.

MOV Terminal Voltage ETAP checks the terminal voltage of a starting MOV against the limit you set in the study case. The alert limit is a percentage based on MOV rated voltage.

Motor Terminal Voltage ETAP checks the terminal voltage of a starting motor against the limit you set in the study case. The alert limit is a percentage based on motor rated voltage.

Motor Slip (Fail To Start) >= Motor slip alert is for identifying fail to start condition for a sta rting motor. It is applicable only for

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 22 de 46

Dynamical M otor Acceleration calculations. The alert limit is motor slip in percent. If after a motor is switched on, its slip is always higher than this limit until the end of simulation, an alert will be generated by ETAP.

Generator In this group, you can specify alert limits for operating values of a generator, generator engine and generator exciter. You can specify a minimum time of violation for generating an alert for each type of alert in this group. When a non-zero value is entered in this field, ETAP will generate an alert only when a continuous violation lasts longer than the minimum time of violation.

Generator Rating A generator rating alert is generated when the output power (MVA) from a generator is larger than the alert limit. The alert limit is in percent based on gene rator rated M VA.

PrimeMover Continuous Rating As the Prime Mover rating of a generator may not be the same as the generator itself, a separate alert for Prime M over rating is needed. A Prime Mover continuous rating alert is generated when the output real power (MW) from a generator is larger than the alert limit. The alert limit is in percent, based on generator Prime Mover continuous rating, entered in the Prime Mover Rating group of the Rating page in the Synchronous Generator editor.

PrimeMover Peak Rating A Prime Mover peak rating alert is generated when the output real power (MW) from a generator is larger than the alert limit. The alert limit is in percent, based on generator Prime Mover peak rating, entered in the PrimeM over Rating group of the Rating page in the Synchronous Generator editor.

Mvar Peak Rating ETAP provides an alert on the maximum var peak rating for generators. A var peak rating alert is generated when the output reactive power from a generator is larger than the alert limit. The alert limit is in percent, based on generator peak var, entered in the Mvar Limits group of the Rating page in the Synchronous Generator editor.

Bus Voltage Due to large and heavily reactive currents drawn from starting motors, system under-voltage is always of great concern in maintaining normal operations during motor starting. To quickly identify any potential under-voltage problems, ETAP provides different levels of alerts for starting motor terminal buses, generator and power grid terminal buses, and other buses with different voltage levels. You can specify a minimum time of violation for generating an alert for each type of alert in this group. When a non-zero value is entered in this field, ETAP will generate an alert only when a continuous violation lasts longer than the minimum time of violation.

Starting Motor Term. Voltage An under-voltage alert for starting motor terminal voltage is generated when the motor terminal voltage is less than the alert limit. The alert limit is in percent based on motor rated voltage. This alert helps identify possible fail to start conditions, especially for Static Motor Starting studies which do not simulate the motor acceleration process. The alert limit can be set based on the manufacturer provided minimum voltage requirement for a motor to start.

Generator/Grid Term. Voltage As a power source delivers heavy starting current, its terminal voltage can also suffer serious drop. It is of great importance to monitor and maintain acceptable voltage level for a generator or power grid during motor starting because it can affect a far larger area of loads than voltage drop on a starting motor terminal bus. An under-voltage alert for generator or power grid terminal voltage is generated when the source terminal voltage is less than the alert limit. The alert limit is in percent based on the generator or power grid rated voltage.

file://C:\Documents and Settings\Administrador\Configuración local\Temp\~hh589C.... 14/07/2015

Motor Starting Analysis

Página 23 de 46

HV Bus, kV >= An under-voltage alert for a high voltage bus is generated when the bus voltage is less than the alert limit. The alert limit is in percent based on the bus nominal voltage. A bus is considered as a high voltage bus if its nominal kV is larger than or equal to the value entered in the field on the same line.

MV Bus, kV Between An under-voltage alert for a medium voltage bus is generated when the bus voltage is less than the alert limit. The alert limit is in percent based on the bus nominal voltage. A bus is considered as a medium voltage bus if its nominal kV is between the voltage limits set for high and low voltage buses.

LV Bus, kV