A Study on Excitation Requirement and Power Balance of Self Excitation Induction Generator for Off-grid Applications Through Experiment and Simulation

Abstract

Research on induction machines gaining popularity for many decades as they can be used for both motoring and generating applications due to many advantages like, cheapest solution, rugged one, requires low maintenance, etc. Induction generators are being used for small-scale power generation in the grid and off-grid modes of operation. When it uses grid-connected applications, the operation is quite simple as it receives the required reactive power from the livegrid, but it may not happen in the case of off-grid applications because of the absence of reactive power to the core of the machine. For such off-grid conditions, the IG is must relate to a suitable minimum capacitor across its stator terminals, and such a generator is called a self-excitation induction generator (SEIG). This paper presents a simple method by using the name-plate details of the considered machine for finding the minimum value of excitation capacitor in a different manner for the successful operation of SEIG. The obtained values from the method are verified through an experimental setup and MATLAB/Simulink of three-phase SEIG. Another crucial challenge in the off-grid operation is the power imbalance of the system. To address the issue, an electronic circuit-based load power balance controller, which works on the principle of continuous sensing of the voltage of the SEIG is proposed and validated the performance of the SEIG system in this paper.