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.
KEYWORDS:
1. FACTS
2. PWM
3. CMC
4. STATCOM
SOFTWARE: MATLAB/SIMULINK
Figure 1.STATCOM network connection.
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.
CONCLUSION:
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.
[1] N. Hingorani and L. Gyugyi, 2000, “Understanding FACTS: Concepts and
Technology Flexible AC Transmission Systems”, New York: IEEE Press.
[2] P. Lehn and M. Iravani, Oct.1998, “Experimental evaluation of STATCOM
closed loop dynamics”, IEEE Trans. Power Delivery, vol.13, pp.1378-1384.
[3] Mahesh K.Mishra and Arindam Ghosh, Jan 2003, ”Operation of a
D-STATCOM in Voltage Control Mode”, IEEE Trans. Power Delivery, vol.18,
pp.258-264.
[4] Arindam Ghosh, Avinash Joshi, Jan 2000, ”A New Approach to Load
Balancing and Power Factor Correction in Power Distribution System”, IEEE
Trans. Power Delivery, vol.15, No.1, pp. 417-422.
[5] Arindam Ghosh,
Gerard Ledwich, Oct 2003,”Load Compensating DSTATCOM in Weak AC Systems”, IEEE
Trans. Power Delivery, vol.18, No.4, pp.1302-1309.
