Дослідження прямого пуску тягового асинхронного електродвигуна за допомогою імітаційної моделі

Abstract

UA: У статті розглянуто роботу тягового асинхронного двигуна (АД) електровоза ДС3 на основі його імітаційної моделі. Імітаційна модель створена на основі системи рівнянь у двофазній нерухомій системі координат α, β. Досліджено прямий пуск при симетричному режимі живлення та отримано характеристики швидкості обертання, електромагнітного моменту та трифазного струму в часі.

EN: Asynchronous electric motors are widely used due to their simple design, high reliability and low maintenance costs. They have been applied in electric drive systems with power from units of watts to thousands of kilowatts. In low-power systems, an unregulated electric drive is used with direct connection of the stator windings to the supply network. However, in high-power systems, such as electric rolling stock, with heavy start-up conditions, the use of direct start-up is inappropriate, since the starting torque is 150% - 300% of the nominal, and the starting current can reach 300% - 800% of the nominal. The quality of the power supply network is also of great importance when it comes to starting an asynchronous electric motor. The voltage drop in the contact network, the phase voltage asymmetry negatively affect the operation of the motors and the service life, causing an increase in the heating of the stator and rotor, which leads to accelerated aging of the insulation and a decrease in engine power. Therefore, the study of starting modes is extremely important for the safe operation of asynchronous motors in rolling stock conditions. The article presents a theoretical analysis of the starting modes of an asynchronous motor and simulates the direct start of an AD914 asynchronous motor using Matlab software. A mathematical model of a traction asynchronous electric motor in the form of a system of differential equations was obtained from a two-phase replacement circuit of an asynchronous motor in a fixed coordinate system α, β. As a result of the simulation, the characteristics of the direct start were obtained: the rotation frequency, the electromagnetic moment and the three-phase stator current. Further studies will examine the effect of supply voltage asymmetry on engine performance.