Improved HERIC single-phase inverter

Abstract

The invention provides an improved HERIC single-phase inverter. The improved HERIC single-phase inverter comprises a direct current power supply, an H bridge arm, a filter circuit and a continuous current circuit, wherein two ends of the H bridge arm are respectively connected to positive and negative poles of the direct current power supply; two ends of the filter circuit are respectively connected to the midpoint of the H bridge arm; the continuous current circuit is connected in parallel to the filter circuit, and comprises two switch tubes which are connected in series reversely and at least one inductor; and the inductor is connected in series with the switch tubes. According to the inverter, at least one inductor is added onto the continuous current circuit of the inverter, and is connected in series with the switch tubes, so that an extra dead zone is not required to be inserted when the inverter is modulated, current passing through the switch tubes and a diode is nearly zero when the switch tubes are connected or disconnected, and the switching loss of the switch tubes and reverse recovery loss of the diode during working of the inverter can be remarkably reduced.

Description

technical field [0001] The present invention relates to the field of inverters, more specifically, to an improved HERIC single-phase inverter. Background technique [0002] An inverter is a device that converts DC power into AC power. It is widely used in the fields of industry and home appliances. The more common one is the HERIC single-phase inverter. [0003] At present, high-frequency switching components are usually used in inverters, and their switching losses account for most of the system's operating time. figure 1 It is the topological structure diagram of the HERIC single-phase inverter. In this topology, two reverse-series switch tubes are connected in parallel on the filter circuit of the inverter for freewheeling, so as to achieve the purpose of isolating the AC output terminal from the DC power supply during the freewheeling stage. , however, when the inverter performs modulation, it is necessary to insert a dead time to prevent the DC power supply from being ...

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Problems solved by technology

figure 1 It is the topological structure diagram of the HERIC single-phase inverter. In this topology, two reverse-series switch tubes are connected in parallel on the filter circuit of the inverter for freewheeling, so as to achieve the purpose of isolating the AC output terminal from the DC power supply during the freewheeling stage. , however, when the inverter performs modulation, it is necessary to insert a dead time to prevent the DC power supply from being short-circuited, so an additional sequence program needs to be added; at the same time, during the modulation process, when the switching tube is turned on or off, the switching tube Both the diode and the diode have a large current passing through, resulting in the obvious switching loss of the switching tube and the reverse recovery loss of the diode during the operation of the inverter.

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