Design and development of model inverter

To meet the requirement of practical teaching of electromechanics course, a model inverter for the school laboratory is designed, which converts the power supply into another arbitrary frequency electric energy to drive the three-phase asynchronous motor to rotate. The motor control system can control the soft start of the motor. Variable voltage and variable frequency speed regulation can be carried out through voltage-frequency conversion circuit and pulse width modulation(PWM) circuit; taking IR2104 as core, the motor drive system uses high-power field effect transistor to convert the weak electric signal which controls the motor into the high-voltage energy which drives motor; motor protection system can detect overcurrent, short circuit, phase gap and overheat, and cut off power supply when necessary to provide protection. The function test and application validation show that the system meets the expected requirements and can be applied to relevant teaching experiments.