Cage rotor induction generator for source equalization of slow intermittent duty loads

Abstract

This paper proposes a control scheme to regulate voltage and frequency of Cage Rotor Induction Generator (CRIG) for source equalization of slow intermittent duty industrial loads. Diesel/mini hydro/ biofuel etc run engine and coupled through CRIG is used for meeting intermittent demand of industrial processes like furnace heating, pressing, packaging etc. where excess demand rises at certain course of time. The control scheme operates in current control mode to draw rated power through CRIG for meeting excess real power demand by an industrial load over sanctioned capacity across back-to-back (BTB) voltage source converter (VSC) interfaced to the PCC. VSC supported with a ripple filter capacitor and small capacity battery storage at DC link to handle the transients during starting/ stabilization of CRIG on the other side and transform the power to PCC and performs source equalization. The proposed system does not require synchronization and resynchronization as required by conventional standby diesel generator set. Additionally the system improves the power quality issues on the grid side to avert perturbations. The current control of VSCs enables control of power flow on DC link to provide source equalization and transient handling. Extraction of rated power through CRIG makes the system efficient, better and cost-effective. The proposed system is simulated in Matlab/ Power System Blockset and the effectiveness of the system is demonstrated through simulation results.