Location

This example model can be found in the software under the category "Benchmarks" with the file name "HVAC_230kV_96Bus_86Line.ecf".

Description

This 60 Hz, 138/230kV HVAC power system model is an 86-bus electrical network. Its 86 transmission lines supply power to a total of 23 loads, rated at 413 MVA (403 MW, 91MVAR) each. Nine ideal voltage sources with lumped equivalent impedance are representing the generators. Full machine dynamics can easily be added. Distributed parameters line models are used for the representation of long lines. PI section models have to be used for the representation of smaller lines. Sixty (60) three-phase PI section lines with self and mutual impedance representation and 26 distributed parameter lines were used. All line sections with a length of 20 km and shorter were simulated using PI sections. 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, three three-phase faults are considered on Buses 5, 17, and 27. The fault times can be modified as required by the user, and new faults can also be added on other buses.

Simulation and Results

As part of the example model setup, the user can perform three types of scenarios. The user can enable or disable five three-phase faults on different model buses. In this case, only two of the three three-phase faults equipped in this model will show the results, each fault is applied independently in different buses. The other 3 three-phase faults can be activated or deactivated following the same instructions given below.

Scenario 1: Three-phase fault on Bus 5

The first scenario is about introducing a three-phase fault on Bus 5 at 0.1s by 0.05s. This scenario gives the user an idea of reliability in power systems, and how it reacts after clearing a fault. 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 Fault1 and also check the disable option within the faults subsystem called Fault2 and Fault3.

Figure 1: Fault configuration settings

The following are the results from ScopeView following the first scenario, a three-phase fault on Bus 5.

Figure 2. Bus Voltage and Fault current with a three-phase to-ground fault at Bus 5

Figure 3. Voltage of some buses with a three-phase to-ground fault at Bus 5

Scenario 2: Three-phase fault on Bus 17

The model is also equipped with a three-phase fault on Bus 17. Similar to scenario 1, the default times for this fault are set to activate at 0.1s and cleared 0.05s later. By default this fault is disabled and only the three-phase Fault1 described in the scenario1 is enabled. To activate only this fault it is necessary to check the Enable option within the fault subsystem called Fault2 and also check the disable option within the faults subsystem called Fault1 and Fault3. 

The following are the results from ScopeView following the three-phase fault on Bus 17.

Figure 4: Bus Voltage and Fault current on Bus 5 with a three-phase to-ground fault at Bus 17

Figure 5. Voltage of some buses with a three-phase to-ground fault at Bus 17