Realization method of zero-current switch of diode neutral point clamped inverting circuit

Abstract

The invention relates to a zero-current switching realization method of a zero-current switch of a diode neutral point clamped inverting circuit, which is realized by the diode neutral point clamped inverting circuit; parallel-connection three-port units M1 and M2 which form the circuit are respectively composed of basic units of N parallel-connection three-port units M1 or M2, which are connected in parallel, the basic unit of the parallel-connection three-port unit M1 (M2) is composed of a power tube Q1 (Q5) and anti-parallel diode D1 (D5) thereof, and a freewheel diode D7 (D9) and a conversion current inductance L1 (L3). All power tubes of 1-N basic units of M1 and M2 are triggered in a circulating way according to the sequence of from 1 to N, and the trigger pulse duty ratio of each power tube is less than 1 / N; the trigger logic of a main power tube Q4 (Q3) is determined by an output logic signal which is obtained by that one N-path input nor gate is input by the trigger logic of N power tubes of N basic units of M1 (M2). The method can realize zero-current switching on of all the power tubes in the basic units.

Description

technical field [0001] The invention relates to a method for realizing zero-current turn-on in a zero-current switch of a diode mid-point clamp inverter circuit, and belongs to the technical field of high-frequency inverter circuits. Background technique [0002] Compared with the traditional half-bridge inverter circuit, the diode mid-point clamp inverter circuit can reduce the rated voltage level of the power tube, reduce the loss of the power tube, and reduce the ripple current of the filter inductor, thereby reducing the distortion of the output voltage. Therefore, although the diode mid-point clamp inverter circuit uses more power semiconductor devices, it still has more advantages in the application of medium and high-power inverter power applications. [0003] In order to further reduce the power tube switching loss of the neutral-point clamped inverter circuit, some soft-switching neutral-point clamped inverter circuits have also been proposed. The typical scheme is ...

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Problems solved by technology

[0005] Although the above-mentioned schemes can realize the soft switching operation of the main power tube, there are still the following disadvantages after careful analysis: (1) all need to add four auxiliary power tubes and four auxiliary freewheeling diodes; (2) the auxiliary power tube The relationship between the PWM signal and the PWM signal of the main power tube is complicated, and it is not easy to generate; (3) The commutation process is complicated, and there are many branches flowing through it, which also increases additional commutation loss

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