Current source type high-frequency link matrix inverter topological structure with soft switching

Abstract

The invention discloses a current source type high-frequency link matrix inverter topological structure with a soft switch, which comprises a power supply network, a current type H bridge, a series resonance tank, a high-frequency transformer, a matrix converter, a CL type filter and a load which are connected in sequence. Large voltage spikes on the primary side of the high-frequency transformer are avoided, and meanwhile zero-current switching of the current type H bridge is achieved. The method can be well applied to a high-frequency transformer with large leakage inductance, meanwhile, the SPWM and SVM modulation method based on the decoupling and coupling thought and suitable for the current source type matrix inverter has the advantage of high and low frequency hybrid modulation, safe commutation of the current source type matrix inverter can be achieved, the number of switching times of the matrix converter is effectively reduced, and the system reliability is improved. And soft switching conditions are provided for all switching tubes of the matrix converter.

Description

technical field [0001] The invention relates to the field of power electronic power converter topology and modulation, in particular to a current source type high-frequency chain-matrix inverter topology structure and modulation method with soft switching. Background technique [0002] The inverter is a converter device that uses power semiconductor devices to convert direct current into alternating current. Traditional inverters use power frequency transformers to achieve electrical isolation, while high-frequency chain inverters use high-frequency transformers instead of power frequency transformers, which overcomes the shortcomings of traditional transformers, such as large size, high noise, and high cost. In order to improve the voltage utilization between the DC side and the AC side, two-stage power conversion is usually used: one is a DAB-based DC / DC converter, and the other is a DC / AC inverter. The intermediate link of this converter requires an electrolytic capacito...

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Problems solved by technology

[0004] Due to the existence of high-frequency transformer leakage inductance, when the transformer leakage inductance current does not match the DC input current, a large voltage spike will be generated on the primary side of the high-frequency transformer. Topology, modulation and its parallel control" introduced a current-mode high-frequency chain matrix inverter and SPWM modulation based on the idea of ​​decoupling, but this document did not consider the above problems

At the same time, when the high-frequency link matrix inverter commutates, a large voltage overshoot is generated on the power tube of the transformer secondary matrix converter. Therefore, the safe commutation of the transformer secondary matrix converter has always restricted the high-frequency link inverter to achieve large Technical Difficulties of Scoping

At present, there are mainly the following safe commutation strategies: ① Soft switching can be realized by adding active clamps to suppress voltage overshoots, but the introduced clamp circuit increases the cost, and the added controllable power tube also makes the control more efficient. Complex; ②The unipolar and bipolar phase-shifting control strategy realizes the natural commutation of the inductor current by means of the commutation overlap of the matrix converter, and realizes the ZVS of the power tube, but there are problems such as difficult control of the commutation overlap time; ③The series resonant circuit is introduced in the front-end inverter to realize the soft commutation of the power tube. At this time, the switching of the power tube is required to occur at the moment of zero current, and the control of the output energy needs to judge the resonant working state of the resonant circuit, which makes the control method complicated

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