130 W Panel Pair Max DC Power

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Hour of Day (CST)

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190 W Panel DC Power to Inverter

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13 13.1

Hour of Day (CST

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Pmax for 130W Panel Pair with I-V Curve Tracer

One Day Six Typical Minutes of the Day

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Results:

Corresponding P Drawn from Neighboring 190W Panel Connected to a Back-of-the-Panel 240Vac Inverter

2

Cloud pattern moving 10-20 meters/sec

A repeating pattern. The circles represent moving shadows due to clouds. When no shadow, use panel clear sky Pmax for the given time of day and panel

orientation. When inside a 50-second diameter (see A), use Pmax / 3. When inside a 5-second circular transition ring (see C – A), assume linear variation

between Pmax and Pmax / 3.

2 mins

5 sec

50 sec

A C

For cloud shadow speed = 10 m/s, A = 500 meters, C = 600 meters

For cloud shadow speed = 20 m/s, A = 1000 meters, C = 1200 meters

#12, Apollo(1200 HP) [ 13.2, 8.9, 2.4]

#11, Longs(200 HP + 0.5 MVA)[ 12.5, 8.5, 2.4 ]

#14, WipeOut (400 HP)[ 12.7, 8.6, 2.5 ]

#16, Shop

#15, BigBoss (1250 HP)[ 13.1, 8.9, 2.5 ]

#13, Jupiter(1200 HP + 0.5 MVA)[ 12.8, 8.7, 2.4 ]

#2, Near Sub S.

#4, PBS(0.5 MVA)

#5, PBN(0.5 MVA)

#20, Substation 138kV,V = 1.02 pu[ 3.3, 2.2, 0.6 ]

#1, Substation 12.47kV[ 11.2, 7.6, 2.1]

#9, Dorsey(250 HP)[ 12.3, 8.4, 2.3 ]

#10, Taylor(400 HP + 1.0 MVA)[ 12.4, 8.4, 2.3 ]

10/12.5/14 MVA Trans., Z = 6.54%, 10 MVA Base, X/R = 10, Load side tap = 1.025, Delta (138)-GWye (12.47),THDI = [ 11.9, 5.2, 1.0 ]

#8, Wilderness (250 HP)#7, Star

#6, Base

MVA)[ 11.7, 8.0, 2.2 ]

#3, Near Sub N.

618 ft. 1000MCM,2 ckts

1606 ft. 1000MCM,2 ckts

1606 ft. 1000MCM,2 ckts

3212 ft. 350CU

3953 ft. 350CU

2224 ft. 350CU

4324 ft.,1/0AL

2965 ft., 1/0AL

1482 ft. 350CU

2718 ft. 350CU

3459 ft.1/0AL

988 ft. 350CU,2 ckts

4324 ft.,1/0AL

2100 ft.1/0AL

Power FactorsCase 4A = 0.82Case 4B = 0.82Case 4C = 0.90

Cable R+ X+Impedances (ohms/mile) (ohms/mile)1000MCM 0.1495 0.1831350 CU 0.2546 0.19761/0 AL 1.0399 0.4710

Isc = 34.4 pu,10 MVA base, X/R =5.0

Example of a small ski area with about 20 nodes

4

• Cloud shadow pattern moves across the distribution system in 1-second steps.

• Shadow depth at each bus is computed, and the PV power at that bus is adjusted accordingly.

• Loadflow and Harmonic Loadflow Re-Solved

• Process continues in 1-second steps, saving bus voltages and powers at each step

5

6

7

0 5 10 15 20 25-0.018

-0.016

-0.014

-0.012

-0.010

-0.008

-0.006

-0.004

-0.002

0.000

Voltage Magnitude Ripple, 50% PV, Wind = 10 m/s, Azimuth = 315 deg

Bus 15

Minutes

PU

Vo

ltag

e D

rop

0 5 10 15 20 25-0.018

-0.016

-0.014

-0.012

-0.010

-0.008

-0.006

-0.004

-0.002

0.000

Voltage Magnitude Ripple, 50% PV, Wind = 10 m/s, Azimuth = 0 deg

Bus 15

Minutes

PU

Vo

ltag

e D

rop