A control method for an inverter device

Abstract

The invention provides a control method of an invertion device, and belongs to the field of power electronics. The invertion device comprises a three-level inverter bridge circuit, a capacitive circuit and a pulse width modulation (PWM) control unit. The three level inverter bridge circuit comprises a diode D1, a diode D2, a power switch tube Q1, a power switch tube Q2, a power switch tube Q3 and a power switch tube Q4. The invertion device is characterized in that the PWM control unit outputs a driving signal DP1, a driving signal DP2, a driving signal DP3, and a driving signal DP4, and when the three-level inverter bridge circuit outputs forward currents and an output level is a Usc / 2 high level, the PWM control unit controls the Q1 to delay a delay turn-on turn-off time Tdelay1 to the Q2 and controls the Q3 to delay a delay turn-on turn-off time Tdelay4 to the Q4; and when the three-level inverter bridge circuit outputs backward currents and the output level is a Usc / 2 low level, the PWM control unit controls the Q2 to delay a delay turn-on turn-off time Tdelay2 to the Q1 and controls the Q4 to delay a delay turn-on turn-off time Tdelay3 to the Q3. According to the control method, whenever an inverter carries out pulse output, middle level balance control can be achieved, and the problem that the switch tubes are uneven in pressure bearing is resolved.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a control method of an inverter device. Background technique [0002] Since the Japanese scholar A. Nabae and others proposed the mid-point clamped three-level inverter in 1980, this topology has attracted more and more attention, and its mature products are gradually being applied. in various fields of the power industry. The mid-point clamped three-level inverter is the earliest structure developed in the multi-level inverter circuit topology. Since the voltage on each power switch tube is only half of the DC side voltage, it is beneficial to Improve the voltage level of the device. At the same time, because the phase voltage has three levels, it is one more level than the traditional two-level inverter. The three-level inverter can output a ladder wave. Under the same switching frequency and control method, The output voltage and current harmonics of th...

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Problems solved by technology

[0005] The task of the present invention is to provide a control method for an inverter device, which has a simple structure, low cost, and low loss, and can solve the problem that the IGBT switch tube of a three-level inverter bears uneven DC bus voltage, and simplifies the circuit The parameter modification method reduces the complexity of the hardware circuit

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