The static synchronous compensator (STATCOM) is used in power system network for improving the voltage of a particular bus and compensate the reactive power.It can be connected to particular bus as compensating device to improve the voltage profile and reactive power compensation. In this paper, a multi function controller is proposed and discussed. The control concept is based on a linearization of the d-q components with cascaded controller methods. The fundamental parameters are controlled with using of proportional and integral controller. In closed loop method seven level cascaded multilevel converter (CMC) is proposed to ensure the stable operation for damping of power system oscillations and load variation.
Figure 1.STATCOM network connection.
EXPECTED SIMULATION RESULTS:
Figure 2. Load terminal dq0 Currents with Load variation
Figure 3. Source terminal dq0 Currents with Load variation.
Figure 4. Iqref output for load rejection.
Figure 5. Source Voltage for load rejection with AGC.
Figure 6. THD of output Voltage of Cascaded Multilevel converter.
Figure 7. THD of output Current of Cascaded Multilevel Converter
Figure 8.Source Active and Reactive power.
Figure 9. Power factor in Load and Source Bus
Figure 10.Three phase Supply Voltage of multilevel converter.
The cascaded controller is designed for seven level CMC based STATCOM. This control scheme regulates the capacitor voltage of the STATCOM and maintain rated supply voltage for any load variation with in the rated value. It has been shown that the CMC is able to reduce the THD values of output voltage and current effectively. The CMC based STATCOM ensures that compensate the reactive power and reduce the harmonics in output of STATCOM.
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