Voltage control of medium to high power three-phase inverter supply systems

[摘要] ENGLISH ABSTRACT:In this thesis a new voltage control method is developed for a three-phase invertersupply system. The inverter supply system consist of a Permanent Magnet Generator, athree-phase rectifier, a three-phase inverter plus LC-filter and a three-phase transformerin series. This system supplies power to a network or to a stand-alone load. The mainfocus of this thesis is on the control aspects of the inverter and the LC-filter.Different voltage control systems are investigated and compared to each other. Fromthese methods the proposed voltage control method is developed where only the outputvoltages are measured to establish good voltage control. All these voltage controlmethods are also simulated with a software package. The proposed voltage controlmethod compares very well with other voltage control methods. The results that areobtained in the simulations are satisfactory. The proposed voltage control method is alsoimplemented in an 8 kW laboratory scale model and, again, very good practical resultsare obtained. A TMS320F240 nsp controller is used to implement the proposed voltagecontrol method. The controller compensates well for load steps, and these resultscompare well to an alternative voltage control method, which was also evaluatedpractically.

[发布机构] Stellenbosch University