The reason this Scenario set “dup” as 1000 pu is from our initial estimate how much ΔMW/(ΔHz/s) is needed from BESS to recover frequency. As we know “dup” represents the required MW change per frequency change in second, it is basically the slope of in pu/(pu/s). Figure 1.1 shows that without BESS, frequency dropped from 60Hz to 59.45Hz in 9s(10s-1s), so dup should be But “dup” must be in per unit whose MW base is BESS Rating 20MW and frequency base is 60Hz, so above equation became This is why this Scenario set “dup” as 1000 pu. frequency recover. The outputs of BESS’s MW and Ipcmd show real power quickly responds to help But the high priority, not Q high outputs of BESS’s MVar and Iqcomd don’t increase too much due to P priority set up in REEC_C to support frequency recover. If the high priority is Q, MVar and Iqcomd of BESS will increase more. The SOC output shows decreases due to BESS’s comsumption to provide power support. Figure 1.1 System Frequency with no BESS, Scenario No.1: Gen Drop Figure 1.2 System Frequency with BESS and Its = 1000, Scenario No.1: Gen Drop “Dup” Figure 1.3 MW Output with BESS in Service and Its = 1000, Scenario No.1: Gen BESS’s “Dup” Drop Figure 1.4 MVar Output with BESS in Service and Its = 1000, Scenario No.1: BESS’s “Dup” Gen Drop Figure 1.5 Bus Voltages with BESS in Service and Its = 1000, Scenario No.1: Gen Drop “Dup” Figure 1.6 Iqcmd and Ipcmd with BESS in Service and Its = 1000, Scenario No.1: BESS’s “Dup” Gen Drop
The reason this Scenario set “dup” as 1000 pu is from our initial estimate how much ΔMW/(ΔHz/s) is needed from BESS to recover frequency. As we know “dup” represents the required MW change per frequency change in second, it is basically the slope of in pu/(pu/s). Figure 1.1 shows that without BESS, frequency dropped from 60Hz to 59.45Hz in 9s(10s-1s), so dup should be But “dup” must be in per unit whose MW base is BESS Rating 20MW and frequency base is 60Hz, so above equation became This is why this Scenario set “dup” as 1000 pu. The outputs of BESS’s MW and Ipcmd show real power quickly responds to help frequency recover. But the outputs of BESS’s MVar and Iqcomd don’t increase too much due to P high priority, not Q high priority set up in REEC_C to support frequency recover. If the high priority is Q, MVar and Iqcomd of BESS will increase more. The SOC output shows decreases due to BESS’s comsumption to provide power support. Figure 1.1 System Frequency with no BESS, Scenario No.1: Gen Drop Figure 1.2 System Frequency with BESS and Its “Dup” = 1000, Scenario No.1: Gen Drop Figure 1.3 BESS’s MW Output with BESS in Service and Its “Dup” = 1000, Scenario No.1: Gen Drop Figure 1.4 BESS’s MVar Output with BESS in Service and Its “Dup” = 1000, Scenario No.1: Gen Drop Figure 1.5 Bus Voltages with BESS in Service and Its “Dup” = 1000, Scenario No.1: Gen Drop Figure 1.6 BESS’s Iqcmd and Ipcmd with BESS in Service and Its “Dup” = 1000, Scenario No.1: Gen Drop
wecc%20battery%20storage%20guideline%20updates_%20bo%204-5-17%20slt%204-7-17%20xx%20sc.docx