POWER QUALITY ENHANCEMENT BY IMPROVING VOLTAGE STABILITY USING DSTATCOM

Priyanka Rani, Ashish Sharma

Abstract: Power Quality issues occur in the power system due to the non standard voltage, current and frequency. For the better power quality there are two things two consider that voltage magnitude should be constant and waveform should be undistorted. If the reactive power in the line varies the active power varies. As the active power is proportional to the magnitudes of the voltages at the sending end and receiving ends, the voltage in the line gets affected due to the reactive power variations. Both the former and the later one can be achieved by maintaining the reactive power within the limits. Whenever there is a change in the reactive power correspondingly the active power and hence voltages gets disturbed. As the load gets changed the impedance of the line also changes correspondingly. If the impedance of the line increases after connecting the load, the active power gets reduced. Similarly if the impedance of the line gets decreased after connecting the load the active power increases. Both the conditions violate the stability of the system. So the design of the power system should be in such a way that stability of the system is maintained by overcoming all these violations. This paper presents the mitigation of voltage sag and swells with different types of load by maintaining the reactive power within limits. For achieving the required phenomena DSTATCOM is used. DSTATCOM implemented in this system makes use of VSC and maintains the voltage magnitude within limits under the influence of voltage sags and swells by supplying the reactive power to the line in case of sag and by drawing the reactive power of the line in case of swell.

Keywords: DSTATCOM, Voltage Stability, Sag/ Swell, Voltage Source Converter

DOI: https://doi.org/10.15623/ijret.2014.0304066