Improved TOGI-Based Voltage and Frequency Control for PMSG Feeding Single-Phase Loads in Isolated Pico-Hydro Generation

Abstract

ABSTRACT This paper deals with the performance of a three-phase permanent magnet synchronous generator (PMSG) for stand-alone pico-hydro generation feeding single-phase load using improved third-order generalized integrator (ITOGI). The proposed control algorithm is used for load balancing, harmonics mitigation and reactive power compensation when a three-phase PMSG feeds a single-phase nonlinear load. A PMSG, voltage source converter (VSC), three-phase diode bridge rectifier (DBR) circuit connected in series with an IGBT switch-based DC–DC converter and a single-phase consumer load are parallelly interfaced at the point of common interface (PCI). The voltage and frequency of the proposed system are controlled in a decoupled manner. The VSC is used for voltage control by providing reactive power compensation along with the power quality improvement. The duty ratio from the frequency controller to IGBT switch connected in series with DBR circuit regulates the system frequency by feeding excess power into an auxiliary load. An ITOGI-based control algorithm is used to extract the fundamental component of load current for power quality improvement by providing proper switching pulses to VSC. The comparative analysis of already existing major state of art techniques is given with proposed ITOGI-based control technique using a Bode diagram and a step response. An appropriate tuning procedure is provided for deciding the control parameters for this algorithm. Simulated behaviour of proposed system and experimental test results are demonstrated using the prototype developed in the laboratory. The feasibility of this control strategy is illustrated using dynamic and steady-state performances of the proposed system feeding the single-phase consumer loads.