Stand-Alone Pico-Hydro Generation System using a High-Efficiency IPM Synchronous Generator

Abstract – This paper presents a successful stand-alone pico-hydro generation system using a high-efficiency interior permanent-magnet (IPM) synchronous generator. A 1-kW 4-pole V-type IPM generator with low voltage regulation is used for laboratory test in stand-alone hydro energy conversion system. It has been found from experimental results that the constant output voltage is supplied stably by the proposed system under wide speed range. Keywords : Hydro g eneration system, IPM generator, Automatic voltage regulation 1. Introduction Recently, global warming has become an important problem. In Japan, there has been a power-shortage problem because of the shutdown of the nuclear power reaction by the Great East Japan Earthquake on March 11, 2011. In such situation, the territorially distributed energy generation using wind or water power attracts attention. The development of permanent-magnet (PM) synchronous generators has progressed rapidly due in part to emergence of the high energy rare-earth magnets like neodymium-iron-boron (Nd-Fe-B) and many designs of PM rotors have been presented in recent years [1]-[6]. However, rare-earth materials such as neodymium and dysprosium are expensive and depend on China for 90% or more of the world share [7]. Therefore, the research for the substitution of Nd-Fe-B to Ferrite magnets has been reported [8]. However, it is considered that the downsizing of the generator needs the high energy rare-earth magnets in stand-alone small power generation system still now. Small wind or water power generation systems have been presented in recent years, for example, [9]-[12]. This paper presents a successful automatic voltage regulation of high-efficiency IPM synchronous generators for stand-alone pico-hydro power generation system. A 1-kW 4-pole V-type IPM generator with low voltage regulation [13] is used for laboratory test in hydro energy conversion system.