A Novel Method for Improving Overload Capability of Stand-alone Power System Based on a Flywheel Induction Motor

Stand-alone power systems are widely used in islands and remote areas. With the rapid advances in the new energy technology, stand-alone power systems have got a rapid development. However, their overload capability is very poor. In this paper, a novel method to improve the overload performance of the stand-alone power system is proposed by using a flywheel induction motor. The flywheel induction motor is composed of a flywheel disk connected to a squirrel cage induction motor. It is controlled to supply the overload power of the stand-alone power supply by charging and discharging. The proposed system is characterized by the following three points: 1) Simple configuration; The flywheel induction motor is directly connected to the inverter-controlled load without any converters. 2) Simple frequency control; The expected active power flow is realized by a small change of the stand-alone power side inverter's output frequency. 3) Low cost system; A decreased power capacity demand for the stand-alone power supply is realized by adding a low cost flywheel induction motor. Experimental results are provided to verify the proposed system.