Abstract:
Abstract: Aim of this paper is to attain the highest voltage sag and swell compensation
using a direct converter-based DVR topology. The projected DVR topology consists of a
direct converter with bidirectional switches, a multi winding transformer with three primary
windings and secondary winding and a series transformer. When voltage swell occurs in a
phase, the same phase voltage can be utilized to mitigate the swell as huge voltage exists in
the phase where swell has occurred. So it is possible to mitigate an infinite amount of swell.
In all the DVR topologies, the converter is only used to synthesize the compensating
voltage. The range of voltage sag mitigation depends upon the magnitude of input voltage
available for the converter. If this input voltage of the direct converter is increased, then the
range of voltage compensation could also be increased. Input voltage of the direct converter
is increased using the multi winding transformer. The direct converter is synthesizing the
compensating voltage. This compensating voltage is injected in series with the supply
voltage through the series transformer and the sag is mitigated. In this proposed topology,
the input voltage for the direct converter is increased by adding the three phase voltages
using a multi winding transformer. Thus the voltage sag compensating range of this
topology is increased to 68% and the swell compensating range is 500%. Ordinary PWM
technique has been used to synthesize the PWM pulses for the direct converter and the
THD of the compensated load voltage is less than 5%. This topology is simulated using
MATLAB Simulink and the results are shown for authentication.
