Research For Parallel Control Strategy Of Shaft Generator's Inverter

Because the fuel expense accounts for total shipping operation cost of 50%～60%, every shipping company meets one of the important issues that how to have taken actions to reduce operation cost resulting from energy consumption. As the shaft generator has a lot of advantages, such as less fuel consumption, reducing marine auxiliary maintenance and preservation cost, impoving engine room environment, and also can satisfy the normal sailing needs of electric power, so it has been used more and more commonly as energy-saving installation of ship.On the board of having many shaft generators system, the shaft generators apply the power to the electrical equipment by connecting in parallel with each other. As the shaft generator gains the CVCF power by Rectifier/Inverter method, the shaft generators parallel connecting is as same as parallel connect of the shaft generators' inverter. The amplitude, frequency and phase of the output voltage of shaft generators' inverter is the same as each other in the parallel connecting, otherwise circulating current will among them. Better performance on restraining circulating current has important influence on shaft generator normal operation, it is the main difficulty of parallel inverter technology. This technology is not only suitable for parallel inverter of shaft generator, but also can used in renewable energy including wind power, solar power and tidal power.The paper mainly studies restraining circulating current. Firstly it is being verified that the dynamic response and interference rejection ability of the inverter can effectively be improved by the voltage and current double closed-loop controlling method. Then Based on the reason of circulating current and the project requirement, this paper concentrates on the study of parallel control strategy based on real and reactive power, which can reduce circulating current obviously with simulation. The last adopting the TMS320LF2407A DSP of TI company as the digital control chip realizes the parallel control strategy based on real and reactive power by adjusting the amplitude and phase of reference sinusoidal wave.