ASYNCHRONOUS MOTOR CURRENT CONTROLLING METHOD WHEN POWERED FROM THE AUTONOMOUS VOLTAGE INVERTER Russian patent published in 2019 - IPC H02P25/62 H02P27/48 H02P27/08 

FIELD: electrical equipment.

SUBSTANCE: invention relates to the field of electrical equipment and can be used for the optimal performance electric drives control. In the induction motor stator current control method during its powering by the autonomous voltage inverter, made with phase arms on transistors, including the motor current control by the inverter phase arms controlling, determine the control error by the corresponding phase driver sine wave comparison with the same phase current actual value; by the control error signal for each phase act on the corresponding phase two-stage relay current regulator, which has the input-output characteristic with the positive and negative hysteresis. During the motor current adjustment depending on its specified and measured values, measure the dc voltage source output voltage, the induction motor angular velocity and the on-off relay current regulators of each phase hysteresis loop changing value, h_+i is with the positive value at the input, h_-i is with negative one, which are calculated according to the equations:

,

,

, , , , , , , where: i=1, 2, 3 is the phase number, t is the current time, U₀ is the voltage at the constant voltage source output, i_{set i} is the average current in phase i setting current value, ƒ_pwm is the PWM modulation frequency, T₀ is the PWM modulation period, ΔT is the difference between the current rise and decrease times in the PWM period, L_Σ is the autonomous inverter load circuit total inductance, R_Σ is the autonomous inverter load circuit total resistance, R₁ is the stator circuit resistance, R′₂ is the rotor circuit reduced resistance, T_e is the autonomous inverter load circuit time electromagnetic constant, I_sh is the autonomous inverter load circuit short circuit current, s is the induction motor rotor slip, ω is the asynchronous motor angular frequency of rotation, ω₀ is the asynchronous motor current setting signal angular frequency.

EFFECT: autonomous voltage inverter current switching frequency stabilization that feeds the induction motor stator, which leads to a decrease in the inverter transistors heating and increase the electric drive energy efficiency.

1 cl, 4 dwg