交流变频电力测功机的控制和实现

针对传统测功机消耗的燃油或电能较高，造成能源浪费且需散热设备的问题，提出了一种交流变频电力测功机控制和实现的方法.该测功机通过异步电机直接转矩控制可以工作在电动和发电两种状态.通过空间电压矢量定向的三相PWM整流控制策略实现了测功机单位功率因数的能量双向流动，电动时从电网吸收能量，发电时把产生的能量反馈给电网；并利用异步电机的直接转矩控制方法来提高测功机的动态响应性能.根据提出的控制策略建立了该测功机的数学模型和运动方程，给出了实验研究方法.实验结果表明，该测功机具有良好的动静态性能，在测试过程中可以节约能源，也减少了整流对电网造成的干扰.

Control and implementation of alternating current variable-frequency power dynamometer

Traditional dynamometers consume much fuel and electrical energy while working,so they waste energy and should be equipped with additional radiators.An AC Variable-frequency Power Dynamometer scheme is presented in this paper.The proposed dynamometer can operate in both motoring and generating states by direct torque control(DTC) of the induction machine.The bidirectional flow of the energy with unit power factor between the power grids and the dynamometer was realized by voltage-oriented control(VOC) three-phase PWM rectifier.The dynamometer absorbed the energy from the power grids in motoring state,and fed back the energy generated by the dynamometer to the power grids in generating state.The dynamometer's dynamic response was improved by the DTC strategy of induction machine.The mathematical model and motion control equations were established based on the proposed scheme,and an experimental method was proposed.Experimental results show that the dynamometer has outstanding dynamic and static performance.The application of this novel dynamometer saves the energy source and decreases the disturbances to power grids caused by rectification.