Inverter, method for controlling inverter and control device

Abstract

The present invention provides an inverter, a method and device for controlling the inverter. The invention aims to improve the efficiency of the inverter. The inverter comprises an active clamping three-level topological structure comprising a first bus-bar capacitor, a second bus-bar capacitor and an inverter circuit. The inverter circuit includes a first switching tube, a second switching tube,a third switching tube, a fourth switching tube, a fifth switching tube and a sixth switching tube; the first switching tube, the second switching tube, the third switching tube and the fourth switching tube are sequentially connected in series in the same direction between a positive direct-current bus-bar and a negative direct-current bus-bar; the fifth switching tube and the sixth switching tube are connected in series in same direction; one end of the fifth switching tube and the sixth switching tube is connected with the series connection point of the first switching tube and the secondswitching tube, and the other end of the fifth switching tube and the sixth switching tube is connected with the series connection point of the third switching tube and the fourth switching tube; theseries connection point of the fifth switching tube and the sixth switching tube is connected with the series connection point of the first bus-bar capacitor and the second bus-bar capacitor; and eachswitching tube is in reverse parallel connection with one corresponding diode. The inverter also comprises a seventh switching tube and an eighth switching tube; the seventh switching tube and the eighth switching tube are connected in series in the same direction between the positive direct-current bus-bar and the negative direct-current bus-bar; the series connection point of the seventh switching tube and the eighth switching tube is connected with the series connection point of the second switching tube and the third switching tube; and the seventh switching tube and the eighth switchingtube are in reverse parallel connection with corresponding diodes.

Description

technical field [0001] The present invention relates to the technical field of power electronics, in particular to an inverter, a method and a device for controlling the inverter. Background technique [0002] With the continuous development of power electronics technology, Pulse Width Modulation (Pulse Width Modulation, PWM) has gradually become the mainstream control method of power electronic converters. Inverters and motor converters are more and more widely used. [0003] In terms of the number of phase voltage levels output by the PWM-modulated inverter, the inverter can be divided into two-level inverters, three-level inverters, five-level inverters, and multi-level inverters. In terms of implementation complexity, it is difficult to implement multi-level inverters with five levels and more. At present, two-level and three-level inverters are widely used in the industry. [0004] The two-level inverter is relatively simple to implement and the cost is low, but since...

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Problems solved by technology

[0011] However, the applicant found that although the 3L-NPC topology or the 3L-ANPC topology has been widely used in the field of power electronics, the efficiency is not high due to the large switching loss and on-state loss of the switching device. , therefore, how to improve the efficiency of the three-level inverter is still a very critical technical issue

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