Power regulators operation research for test station of rolling stock traction electric motors
In the article the issue of energy efficiency of power regulators used at test stations of traction electric motors of rolling stock is considered. The paper analyzes modern equipment used at test stations based on mathematical modeling. Mathematical modeling allows to make sure that switching dips in the sinusoidal curves of the supply voltage exist in thyristor converters, as well as a non-sinusoidal current curve. Switching dips are also present in the supply voltage curves. The presence of these disturbances is caused by the existing switching interval, as a result of the phase-to-phase short circuit of the switched phases. Besides, the existing power regulators reduce the effective voltage. The analysis performed of the operation of the proposed power regulators in the test station, based on which all harmonic components of the voltage and current of the supply network are analyzed. Based on the refined law of conservation of energy, a device is proposed, which, by changing the input electrical resistance, regulates the power of the test station. The performed mathematical analysis of the power controllers of the test station for the supply network leads the conclusion that when using rectifiers on diodes, the entire potential of the power source is used. The impact on the supply network is minimized by using the proposed power regulators based on an electric semiconductor variator. The proposed regulators allow not loading the supply network with additional currents, ruling out the negative impact, which currently is avoided only by the introduction of additional filter elements. These devices provide a power factor close to unity and maintain high electromagnetic compatibility of the test station with the mains supply throughout the entire power control range.