An Autonomous Power-Supply Station Based on an Asynchronous Generator with a Phase-Wound Rotor and a Low-Power Frequency Converter

Abstract

Today, asynchronous and synchronous generators with double-link full-power frequency converters are the main options for designing highly efficient three-phase voltage sources with an internal combustion engine (ICE) as a prime mover and a variable rotation frequency as a function of the load. It is required to develop and study the efficiency of the use of an autonomous power-supply station with a variable rotation frequency based on a low-power frequency converter in order to provide a decrease in its cost with the potentialities of saving ICE fuel through controlling the frequency depending on the load. The power station and its control system is described both at a structural and at a functional level. The characteristics of the station have been studied by means of computer simulation with the use of the Delphi software package. To assess the potential fuel efficiency of the power station, a multiparameter characteristic of the YaMZ-238 internal combustion engine has been used. A functional diagram of the power station and a block diagram of its control system without using a rotation-frequency sensor are presented. Timing diagrams for the simulation of its operation with the use of an asymmetrical load, as well as its energy characteristics, are presented. The energy characteristics and potential fuel savings of the internal combustion engine when the power station operates with a symmetrical active-inductive load under the conditions of a multiple decrease in the power of the frequency converter with respect to the nominal power of the load. It is shown that, unlike well-known analogues, the developed power station makes it possible to ensure an at least twofold effective rotation-frequency control range of the internal combustion engine while limiting the nominal converter power to 20% of the nominal load power, which provides preconditions for significant fuel savings. The use of the power-supply station in the proposed design makes it possible to reduce its cost by decreasing the power of the converter and increasing the energy efficiency thereof via controlling the ICE rotation frequency with a satisfactory maintenance of accuracy of the output voltage under the conditions of a significantly asymmetric load. The reliability of the results obtained in the course of the studies has been confirmed by means of computer simulation.