Voltage control of variable speed SEIG with Z-Source inverter

This paper presents a voltage control method for a three-phase Self Excited Induction Generator (SEIG) with Z-Source inverter. A Z-Source inverter with unified control technique is proposed which can boost the voltage and generate the desired output voltage efficiently when the low voltage is available at generator terminals due to low speed operation of generator. And also when the speed of generator is high giving higher voltages the inverter operates as a traditional voltage source inverter to buck the voltage. Thus proposed system is capable of both boosting and bucking voltage. Thus making system suitable for wind turbine distributed Generation system. In unified control technique a unified voltage vector is used which is composed of both traditional voltage vector and unique boost factor which provides fast dynamic response to maintain constant output voltage of inverter in variable speed operation of SEIG.