Lab 1. – Is DROOP really needed?

Initial conditions

  • 52G1, 52G2, 52Load and 52Line are all open;
  • Both units DROOP is 5[%];
  • Both units LOAD output is 0[%];
  • Both units SPEED output is 0.8[%];
  • Both units operate at FSNL that is a bit below 3000[RPM];
  • STRONG GRID selected.

Step 1)

Set both units DROOP  to 0[%].  The RPM should move to exactly 3000RPM.

Step 2)

Close 52G1, 52G2 and 52Line.  Nothing should change.

Step 3)

By clicking on UP buttons set both units LOAD outputs to 20[%].  Both units power outputs should go to 20[MW].  This step is to avoid Reverse Power Protection.

Step 4)

Select LOOSE GRID button.  The frequency should start to fluctuate. In a case frequency is exactly 50[Hz] the outputs are unchanged.  As long the frequency is below 50[Hz] both units outputs are keep going up.  As soon frequency raises above 50[Hz] the outputs are driven down.

Conclusion

Without some amount of DROOP the unit output is out of control in a case system frequency moves anywhere from exactly 50.00[Hz].

 

Lab 2. – Load Sharing

Initial conditions

  • 52G1, 52G2, 52Load and 52Line are all open;
  • Both units DROOP is 5[%];
  • Both units LOAD output is 0[%];
  • Both units SPEED output is 0.8[%];
  • Both units operate at FSNL that is a bit below 3000[RPM];
  • STEADY LOAD selected.

Step 1)

Close 52G1, 52G2 as well as 52Load. Each unit will take 25[MW] load. Load Share Commands appear available.  After a while the frequency stabilizes at  97.37[Hz].

Step 2)

Select UNSTEADY LOAD Option. The load starts to fluctuate. Both units equally load and unload however, the frequency fluctuates as well and never reach 50.00[Hz].

Step 3)

Select LOAD SHARE ON for both units at the same time. The frequency goes to 50.00[Hz]. Both units continue to load and unload equally keeping  50.00[Hz] together. Select both units LOAD SHARE OFF and monitor the difference.

Conclusion

This governor design has load sharing option. This option provides load sharing between units enabling paralleled generators governors to operate together in a semi-isochronous mode .

 

 

 

 

 

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