When the secondary voltage is lower than the bus voltage, the D-STATCOM acts like an inductance absorbing reactive power. This voltage is provided by a voltage-sourced PWM inverter. This reactive power transfer is done through the leakage reactance of the coupling transformer by generating a secondary voltage in phase with the primary voltage (network side). The D-STATCOM regulates bus B3 voltage by absorbing or generating reactive power. This load variation will allow you to observe the ability of the D-STATCOM to mitigate voltage flicker. The variable load current magnitude is modulated at a frequency of 5 Hz so that its apparent power varies approximately between 1 MVA and 5.2 MVA, while keeping a 0.9 lagging power factor. The 600-V load connected to bus B3 through a 25kV/600V transformer represents a plant absorbing continuously changing currents, similar to an arc furnace, thus producing voltage flicker. A shunt capacitor is used for power factor correction at bus B2. Two feeders (21 km and 2 km) transmit power to loads connected at buses B2 and B3. DescriptionĪ Distribution Static Synchronous Compensator (D-STATCOM) is used to regulate voltage on a 25-kV distribution network. This type of model is not available for the D-STATCOM, but it is available for the STATCOM, a similar device, in the power_statcom.mdl model. This model allows using much larger time steps (typically 50 microseconds), thus allowing simulations of several seconds.Īlternatively, a third type of model can be used for simulating on larger time frames: the phasor model. This model does not represent harmonics, but the dynamics resulting from control system and power system interaction is preserved. In this type of model the IGBT Voltage-Sourced Converters (VSC) are represented by equivalent voltage sources generating the AC voltage averaged over one cycle of the switching frequency. The average model (discrete) such as the one presented in the power_dstatcom_avg model in the FACTS library of examples. This model is well suited for observing harmonics and control system dynamic performance over relatively short periods of times (typically hundreds of milliseconds to one second). In order to achieve an acceptable accuracy with the 1680 Hz switching frequency used in this example, the model must be discretized at a relatively small time step (5 microseconds).

The detailed model includes detailed representation of power electronic IGBT converters. The detailed model (discrete) such as the one presented in this example. When modeling VSC-based energy conversion systems in Specialized Power Systems, you can use two types of models, depending on the range of frequencies to be represented : the detailed model and the average model.

Statcom matlab simulink model