Description

This example shows the operation of a Unified Power Flow Controller (UPFC). It features a series and shunt converter, with their respective controllers. Each converter consists of four three-level inverters, fed by four phase-shifting zig-zag transformers. The shunt converter operates as a STATCOM whereas the series converter is in power flow control mode. 

UPFC is connected between bus B_1 and B_2. The transmission system has a 500 kV voltage level. Each converter consists of a 100 MVA, 48 pulse GTO based converter. The conduction angle for the shunt converter is set by a constant parameter (Sigma) equal to 172.5 degrees. By operating at this angle the significant harmonics present in the generated voltage waveform are at a higher harmonic rank, allowing for quasi-sinusoidal voltage generation on the bus.

WARNING: The example does not work with icc compiler on RedHat and CentOS.

Location

This example model can be found in the software under the category "FACTS & HVDC" with the file name "UPFC.ecf".

Simulation and Results

On the Pref_Qref_Vref block, make sure that for the active power the constant value is 6 pu, in the delay Td=0.5s, Ton=100s and the addition parameter has gain value of g1=-1, g2=1. Similarly, for the reactive power, make sure the constant value is -0.6 pu, in the delay Td=1s, Ton=100s and the additional parameter has gain value of g1=1.3, g2=1. On the UPFC block, the “Shunt converter control” tab put the Sigma parameter with a value of 172.5 degrees. Also, set on the tab “General” the operation mode as Auto (Power Flow Control). By selecting those parameters the system will control the active and reactive power flowing between the two connected buses. The initial and final parameters correspond to a pu/100 MVA base.

Run the simulation and open the Scopeview template. Observe on the first page the results of the active and reactive power, compared with their references. The acquisition parameters are set to run a run of 1.5 seconds. At the beginning P=600 MW, Q=-60 MVar. After 0.5 seconds P is set to 500 MW. At 1 second Q is ramped up to 70 MVar. The parameters of the “Series converter control” tab are set by default, for the rate limiter section, to “active power rising/falling slew rate” (10/-10), “reactive power rising/falling slew rate” (15/-15)

References

[1] https://www.mathworks.com/help/physmod/sps/examples/upfc-detailed-model.html