Extreme control system of auxiliary drive of electric locomotives

Abstract

One of the ways to increase the energy efficiency of an induction motor is the use of an extreme control system. The increase in energy efficiency is achieved by reducing the power consumed by the motor to extremely low values by changing the value of the rotor flux linkage. The purpose of the work is to increase the energy efficiency of the vector control system of an induction motor by optimizing the setting of the rotor flux linkage. The flux linkage optimum value is determined in accordance with the criterion of the minimum consumed stator current depending on the set value of the electromagnetic torque on the motor shaft. The disadvantage of classical systems of extreme regulation is low performance due to the large value of the search time for the extremum point. Thus, classical search engines are applicable in established operating modes. In the event of a deviation in the parameters of the engine or a change in its operating mode, it is necessary to carry out a new search for an extremum with each change, which is impossible due to low speed of performance. In this regard, the use of classical extremal controllers is limited. To eliminate this drawback, it is proposed to use an extreme control system with a variable step during the operation of the regulator. Herewith, the control system provides an increase in the energy performance of the asynchronous motor both in the nominal and non-nominal operating modes. It is advisable to use the proposed regulation algorithm in the drive of auxiliary machines of an electric locomotive. A typical asynchronous motor with a squirrel-cage rotor of the 4A225 M4 U2 type, installed in the VL85 motor-fan drive, was used in the work. The proposed extreme control system allows to reduce power losses in the engine in all modes of its operation. For the motor 4A225 M4 U2 considered in the work, the stator current was reduced by 15 %, and the search time by 40% in comparison with the classical method of extreme regulation with a constant search step.