S06-SoundTutorial
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AUDIBLE SOUND REGULATORY REQUIREMENTS FROM A UTILITY PERSPECTIVE
JANE ANN VERNER P.E. MARCH 2006
Overview
F a ct c t o r s T h a t D et et e r m i n e A cc c c e p t a b l e So S o u n d L ev ev e l s Ba ck g r o u n d I n f o r m a t i o n Z o n i n g Re q u i r e m e n t s P r o j e ct c t S p e ci c i f i c Fa Fa ct c t o r s To To H e l p M ee e e t Zo Z o n i n g Re Re q u i r e m e n t s
Factors That Determine Acceptable Sound Levels
P r o x i m i t y o f su su b st at i on o r t r a n s f o r m er t o s lee p in g f a c cii l i t i e s, s, ei t h er c o m m er ci al o r r esi d en t i al Zo n i n g o r u s e o f l a n d s e l ev ev e ls I n d u s t r i a l h i g h e r n o i se permitted Ti m e o f d a y o r n i g h t f o r s o u n d activity Dur at ion, volum e and n at ur e of so u n d s u ch a s t o n e , f r e q u e n c y an d b r o ad b a n d
Background Theory
Pe r i o d - Ti m e t h a t i t t a k e s f o r o n e v i b r a t i o n c y c l e ( T se c) Fr e q u e n c y # o f v i b r a t i o n c y c l es p e r se c ( f H z) F = 1/ T 5 0 0 H z = 1 / 0 .0 0 2 se c
Background Theory
Pu r e To n e s j u st o n e Fr e q u e n c y N o i s e – co n t a i n s m a n y frequencies Tr a n s f o r m e r s So u n d s Co r e , w i n d i n g s & co o l i n g Co r e n o i s e 1 2 0 H z & e v e n harmonics H u m a n A u d i b l e Ra n g e 2 0 H z t o 2 0 ,0 0 0 H z 2 0 H z t o 1 6 ,0 0 0 H z
Sound Chart
Background Theory
A w e i g h t e d So u n d s – si m u l at e s t h e f r e q u e n c y r e sp o n s e o f t h e h u m an ear . Ad j u st ed p ri m ar i l y f o r l o w f r e q u e n c i es.
Se e C5 7 .1 2 .9 0
Ta b l e s 9 & 1 0
A Weighted Sound Curve
Perception of Sound Intensity Ch a n g e i n d B 1 dB 3 dB 5 dB 10 dB
H u m a n Pe r ce p t i o n I m p e r ce p t i b l e Ju s t N o t i ce a b l e Cl e a r l y N o t i ce a b l e Su b s t a n t i a l Ch a n g e
Requirements
M o st Co m m o n 7 A M t o 7 PM 6 5 d b A 7 PM t o 7 A M 5 5 d b A
So m e ar e a s m o r e s t r i n g e n t Li m i t o f 1 0 d e ci b e l s o v e r e x i s t i n g so u n d l ev e l s
Requirements PHI NJ (Con’t) Continuous sound level limited to 50 dbA
Hz 3 1 .5 63 125 250 500 1000 2000 4000 8000
dB 96 82 74 67 63 60 57 55 53
Project Specific Factors Screening and Landscaping
Project Specific Factors
B a se l i n e so u n d m e a su r e m e n t s Gr e e n f i e l d si t e - M ea su r e a t si m i l a r s i t e To u r f o r z o n i n g p e r s o n n e l I n c l u d e so u n d l i m i t i n y o u r s p ec Sp e ci f y l o w s o u n d e m i t t i n g equipment Se t b a c k s I EEE C5 7 .1 3 6 A n n e x B
Calculating Transformer Noise Level with Setback from Property Line Step 1: Determine Transformer Sound Power Level (Lw) Lw = LpIEEE + 10 log10 (Surface Area) (B1) Where: Lw = Transformer Sound Power Level (dBA) LpIEEE = Transformer Sound Pressure Level at IEEE Locations (dBA) Surface Area = IEEE Measurement Surface Area in m2 = 1.25 x Transformer Height x Measurement Perimeter (B2)
Calculating Transformer Noise Level with Setback from Property Line Step 2: Calculate Sound Pressure Level at a Specific Location Assuming hemispherical sound wave radiation LpR = Lw – 10 Log10 (2πR²) (B3) Where: LpR = Sound Pressure Level at the Specified Distance, R (dBA) Lw = Transformer Sound Power Level (dBA) R = Distance from Transformer to Location in m. This resulting Lp calculated from Step 2 will provide an estimate for a single transformer installation.
Calculating Transformer Noise Level with Setback from Property Line The maximum allowed sound level at a property line is 53 dBA. The property line is 122 meters from the transformer. The height of the transformer is 6.1 meters and the perimeter is 18.3 meters. What should the maximum allowable sound pressure level of the transformer be at the IEEE locations? LpR = 53 dBA, R = 122 m, h = 6.1 m, p = 18.3 m Using equation (B2) Surface Area = 1.25 x h x p = 1.25x (6.1 m) x (18.3 m) = 139.5 m2 Rewriting equation (B3) Lw = LpR + 10 log10 (2πR2) Lw = 53 dBA + 10 log10 (2 π(1222)) = 102.7 dBA ⇒ Using equation (B1) Lw= LpIEEE + 10 log10 (Surface Area) LpIEEE = 102.7 dBA – 10 log10 (139.5) = 81.3 ⇒ dBA The maximum allowable sound pressure level of the transformer at the IEEE locations is 81 dBA.
Summation of Levels of Multiple Sources # o f I d e n t ica l So u r ce s
2 3 4 5
d B ad d ed t o single level 3 5 6 7
dB dB dB dB
Tutorial Session IEEE Transformer Committee
Ramsis Girgis
r e m r o f s n a r T r e w o P A B 1 B 0 B / A 5 0 / © 1
Transformer Noise Sources & Characteristics
Monday, March 20, 2006
Topics
2 r e m r o f s n a r T r e w o P A B B B A ©
Sources / Components of transformer noise
Characteristics of each noise component
Relative magnitudes of no-load and load noise
Is Load Noise an issue?
Sources of Noise in a Transformer
No-Load Noise
Core Noise
Cooling Equipment Noise
Load Noise
Total Noise = No-Load Noise + Load Noise 3 r e m r o f s n a r T r e w o P A B B B A ©
4 r e m r o f s n a r T r e w o P A B B B A ©
s e c r u o S & m u r t c e p S y c n e u q e r F
Core Noise
Caused by Magnetostriction of core material
Mainly 120 Hz, 240 Hz, and 360 Hz with some 480 Hz
100, 200, 300, and 400 Hz for 50 Hz operation
Relative magnitudes are determined by core material & flux density
An unexpectedly high level of a frequency component would indicate core / tank resonance
5 r e m r o f s n a r T r e w o P A B B B A ©
Frequency Spectrum of Core Noise - 1 80
70
B d , l e v e l e r u s s e r p d n u o S 6 r e m r o f s n a r T r e w o P A B B B A ©
60
50
40
30
20
10 5 . 2 1 5 3
0 0 3 0 0 5 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 4 5 6 8 1 0 1 2 1 6 2 0 2 5 3 1 4 0 5 0 6 3 8 0 0 0 2 5 0 5 0 0 0 0 0 6 2 0 2 5 3 1 4 0 5 0 6 3 8 0 0 1 1 1 0 1 2 1 6 2 0 1
Frequency, Hz
Frequency Spectrum of Core Noise - 2 90 80 ) B d ( e r u s s e r P d n u o S
7 r e m r o f s n a r T r e w o P A B B B A ©
70 60 50 40 30 20 10 0 5 5 . 2 1 3
0 0 4 5
3 8 0 6
0 0 0 3 0 0 0 0 0 0 0 1 2 5 1 6 0 2 0 0 2 5 0 3 1 5 4 0 1 5 6 8 1 0
Frequency (Hz)
Cooling Equipment Noise
Caused by Fans and Pumps
Moderate levels of low-frequency ( 2,000 MW M W per mile2
D e n s e U r b a n En En v i r o n m e n t
3
T y p i c a l 1 3 8/1 3 k V Su b s t a t i o n Syn Bus Syn Bus Breakers
138/13 kV
65 MVA
Circuit Switcher
Transformer Breakers
To Network Load
Syn Bus
H i s t o ri c a l T ra ns f or m e r N o i s e Requirement
New York City Noise Code – Octave band noise specification with annoyance criteria Locate substations in commercial zones next to major roads Industry standards: transformer no -load and cooling no-load equipment (pumps & fans) noise
Isolated areas: 65 – 85 db(A) Urban areas: 60 - 65 db(A) Residential: Main tank in enclosed room with radiators in ventilated area
T y p i c a l Su bs t a t i o n A r e a 1 9 7 0s
Co m m e rc i a l – Re s i de nt i a l Z on e
5 T r a ns f o r m e r V a u l t s I n -L i n e
T r an s f o r m e r L o a d N o i s e Fi e l d Me a s u r em e n t s
Survey: 6 transformers from 4 different manufacturers Power Loading: 30 -50 % of nameplate rating 30-50 Voltage: 105 % of nameplate rating
68 – 78 db(A)
M a n h a t t a n Su b s t a t i o n De s i gn Co n c ept nc
Midtown Manhattan Mixed residential and commercial Limestone veneer, granite base Louvers lit to appear as storefront Planters in sidewalk
10
N Y Ci t y M 1 R N o i s e Pe r fo r m a n c e Re q u i r e m e n t (So u n d Pr e s s u r e L e v e l ) Manufacturing Zone Octave Band Freq. (Hz)
Maximum Average Sound Level (db)
20 - 75
79
75 - 150
74
150 - 300
66
300 - 600
59
600 - 1,200
53
1,200 – 2,400
47
2,400 – 4,800
41
Above 4,800
39
T ra nss m i s s i o n Sys r an Sy s t e m V o l t a ge ge Re qu i re m e nt s (Ov e re x c i t a t i o n ) Voltage Class (kV)
138
345
Voltage Limits (kV)
Duration
Range
Lower
(minutes)
Over 160
-
0
153153-160
-
10
146146-152
124
30
130130-145
130
Continuous
Over 400
-
0
381381-400
-
10
363363-380
311
30
328328-362
328
Continuous
T y p i c a l A r ea St a t i o n N o rrm m al Op e r at i n g Co n di t i o n
140 -145 kV HV bus voltage 140-145 Non -summer loading: Four transformers loaded Non-summer to approximately 30 % of nameplate rating (65.3 MVA) Summer loading: Four transformers loaded to approximately 80 - 90 % of nameplate rating (65.3 MVA) NLTC: 125.4 kV position LTC: 12L position (12.558 kV position) Power factor: 0.93
T y p i c a l A r ea St a t i o n Co nt i n g e n c y Op e rra att i n g Co n di d it i o n
138 -140 kV HV bus voltage 138-140 Summer loading: Three transformers loaded to approximately 143 % of nameplate rating (65.3 MVA): 93.8 MVA for 8 -hours 8-hours NLTC: 125.4 kV position LTC: 16R position (15.468 kV position) Power factor: 0.93
L ow N o i s e T r an s f o r m e r De s i g n s a ns
65 MVA, 132 -13.8 kV Transformer 132-13.8 93 MVA, 132 -27 kV Transformer 132-27 65 MVA, 132/65 -13.8 kV Transformer 132/65-13.8 234 MVA, 138 kV +/ +/-- 25 25°° Phase Angle Regulator * 234 MVA, 335 -136-13.8 kV Auto-transformer Auto -transformer * 335-136-13.8 420 MVA, 335 -136-13.8 kV Auto -transformer 335-136-13.8 Auto-transformer 150 MVAr, 345 kV Shunt Reactor (Future) * New designs for 2007 -08 2007-08
Re v i s e d 2 0 0 5 N Y C N o i s e Co d e
New law provides for maximum sound levels measured, with the windows open, within a residence in either a mixed use or residential use, or within a commercial building.
Co m p a r i s o n o f N Y C Z R v s . N Y C N o i s e Co d e L i m i t s (So u n d Pr e s s u r e ) 80 ) B d ( l e v e L d n u o S
70 60 50 40 30 31.5
63
125 500 1000 Octave Band Frequency (Hz)
2000
4000
8000
ZR Property line M1R
ZR Property line M1
Des ign Lim it outside res idential
Design Limit outside com mercial
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