Location

This example model can be found in the software under the category "Benchmarks" with the file name "HVAC_500kV_200Bus.ecf".

Description

This model simulates a 500 kV ac transmission network with 200 buses, 28 hydraulic generation turbine plants (synchronous machines and regulators), and 60 loads. The nominal operating frequency of the network is 60 Hz. Each of the hydraulic plants is simulated as one combined synchronous machine (SM) with turbine and governor, excitation system, and power system stabilizer, connected to the grid through a 3-phase 2-winding step-up transformer.  With HYPERSIM, it is possible to observe the behavior of the network with fault occurrences (A-gnd, AB-gnd, ABC-gnd). It is also possible to study the electromagnetic transients when the network loses machines or lines. Instability, islanding, and resonances are phenomena that can be studied and validated with the model. During the simulation, any kind of fault, including single-line-to-ground, three-phase, and two-phase-to-ground faults, can be introduced in different locations. For this example, two three-phase faults are considered on Buses 7 and 9. The fault times can be modified as required by the user, and new faults can also be added on other buses.

All the machines of the generation system are controlled by internal exciters, governors (speed regulators), and stabilizers. The user can change this configuration by double-clicking on the machine subsystem and changing the values in the mask. The following is a snapshot of the machine configuration:

Figure 1: Synchronous machine configuration settings

Simulation and Results

As part of the example model setup, the user can perform one scenario. The user can enable or disable two three-phase faults on different model buses.

Scenario 1: Three-phase fault on Buses 7 

The first scenario is about introducing a three-phase fault on Bus 7 at 0.1s by 0.1s. The user can change these settings by going into the fault subsystem and changing the values of T1 and T2, configuring the fault activation and clear times, respectively. . By default only this fault is enabled,  it is necessary to check the Enable option within the fault subsystem called Flt_B7 and also check the disable option within the faults subsystem called Flt_B9.

Figure 2: Fault configuration settings

The following are the results from ScopeView following the first scenario, a three-phase fault on Bus 7.

Figure 3: Voltage of Buses 7 and 92 with a three-phase to ground fault at Bus 7.

Figure 4: Voltage of Bus 7 and  primary winding current of transformer 1 with a three-phase to ground fault at Bus 7

Figure 5: Machine speed and voltages with a three-phase to-ground fault at Bus 7.

Scenario 2: Three-phase fault on Bus 9

The model is also equipped with a three-phase fault on Bus 9. Similar to scenario 1, the default times for this fault are set to activate at 0.1s and clear 0.1s later. By default this fault is disabled and only the three-phase Flt_B7 described in scenario 1 is enabled. To activate only this fault it is necessary to check the Enable option within the fault subsystem called Flt_B9 and also check the disable option within the faults subsystem called Flt_B7. 

The following are the results from ScopeView following the three-phase fault on Bus 9.

Figure 6: Voltage of Buses 7 and 92 with a three-phase to ground fault at Bus 9.

Figure 7: Voltage of Bus 7 and  primary winding current of transformer 1 with a three-phase to ground fault at Bus 9

Figure 8: Machine speed and voltages with a three-phase to-ground fault at Bus 9.

See Also

Synchronous Machine (pu Standard), Three phase fault, 2-Winding 3-Phase Linear Transformer