A New control strategy for DVR is proposed

In this paper a new control strategy for dynamic voltage restorer (DVR) is presented to compensate effectively voltage sags. In thisstrategy, load and supply voltage magnitude and angle are estimated by least error square in short time. Advantage of this method is reducingnoise, distortion and harmonic on estimation parameters. Accordingly, these parameters are controlled for each phase separately. Also, It shouldbe noted that due to angle estimation by LES filters, control system does not require phase-locked Loop and this issue causes increase in speed ofcontrol system response. In addition, a P+Resonant and Posicast controller are used to eliminate the steady-state error and improve transientresponse in DVR, respectively. The proposed control system is simulated, using PSCAD/EMTDC software by induction motors starting isconnected to ۱۳ bus IEEE standard network. Finally, the simulation results prove that the proposed control scheme performs satisfactorily undersudden changes of load

Keywords:

dynamic voltage restorer , voltage sag , least error squares filters , control system , power quality