INFLUENCE OF TRANSFORMER CHARACTERISTICS ON INVERTER PERFORMACE
The article assesses the influence of the parameters of the magnetization branch of the transformer on the inverter start-up mode. The study is implemented by simulation in Simulink Matlab. Simulation is carried out using various SPS-models of the transformer. It is shown that the nature of the inverter start-up mode depends on which model of the transformer is used. When an inverter with a linear model is switched on, there are no magnetizing current surges. Taking into account the nonlinear nature of the magnetization characteristic leads to the appearance of magnetization current surges, which cause transformer primary current surges and, as a result, surges in power switch currents, which can lead to their failure. It is concluded that the value of the inrush current of the transformer in transition mode is determined by the type of magnetization characteristic. It is shown that the amplitude of the current surge depends on the value of the residual induction. For the same value of the residual induction, the inrush currents of the magnetization depend on the angle of inclusion of the sinusoidal modulating voltage. In case of «unsuccessful» switching on, the amplitude of the primary current can exceed several times the steady-state value. It is shown that a decrease in inrush currents can be achieved by smoothly changing the angle of inclusion of the modulating sinusoidal voltage.