Design and Simulation of Current Sensor based Electronic Load Controller for Small Scale Three Phase Self Excited Induction Generator System

Abstract

In standalone renewable energy systems, the power balance methods must exist to match the generated power and load demand; otherwise the excess power creates the disturbance in terms of voltage and frequency fluctuations. This paper presents a design and simulation of an electronic load controller (ELC) for the power balance in constant power prime mover-coupled three phase self-excited induction generator (SEIG) system. A current sensor based ELC is designed in such a way that to operate the generator unit always at its full capacity by coordinating between the two load systems termed as main and dump load. The controller unit has an uncontrolled 3-phase full-bridge rectifier circuit, a logically controlled insulted-gate bipolar transistor (IGBT) chopper switch, and a current sensor. The current sensor provides the feedback signal to the gate trigger circuit of IGBT and which inevitably controls the ON/OFF position of the switch. The ON condition of switch means a partial or full portion of generation power is diverted to the dump load, and the sum of both loads is equal to the rated capacity of SEIG. The proposed system is simulated in MATLAB, and the power balance is achieved with help of ELC. The voltage regulation of SEIG is addressed by adding extra reactive power (VAR) compensation. Further, in this study, the basic configuration of SEIG and the importance of self-excitation phenomena for voltage generation are also highlighted.