Electronic load controller with power quality improvement of isolated induction generator for small hydro power generation

This study deals with an implementation of an instantaneous reactive power theory-based electronic load controller (ELC) for regulating the voltage and frequency of an isolated induction generator system (IG) that can supply electricity in remote areas. This ELC provides the fundamental reactive power and compensates harmonics of load currents. The proposed ELC is a combination of voltage source converter (VSC) with a dc link capacitor, a chopper and an auxiliary load at its dc bus. It controls active and reactive powers of the small hydro plant thus regulating the voltage and frequency of IG system. This ELC also balances the currents of the IG system under unbalanced load currents and eliminates the harmonics of the load currents thereby acting both as a load balancer and a harmonic eliminator. The zigzag/star transformer optimises the dc bus voltage of VSC and acts as a neutral current compensator. The proposed IG along with its ELC is implemented on a 3.7 kW IG system.