Through physical separation-type Z-source inverter with high booster multiple

Abstract

The invention relates to a through physical separation-type Z-source inverter with high booster multiple, which relates to the field of Z-source inverters, and comprises a direct current voltage source, a first blocking diode, a second blocking diode, a Z-source impedance network and a three-phase inverter bridge; and the Z-source impedance network comprises a first inductor, a second inductor, a first capacitor and a second capacitor which form an X-shaped structure. The inverter is characterized by also comprising a full-control switch device, a large capacitor and a power diode; the negative pole of the second capacitor and the collector of the full-control switch device are parallelly connected to the anode of the power diode; the emitter of the full-control switch device is connected with the negative pole of a direct current power supply; the cathode of the power diode is connected with the positive input end of the three-phase inverter bridge; the large capacitor is parallelly connected with the three-phase inverter bridge; and the positive pole and the negative pole of the capacitors are respectively connected with the positive input end and the negative input end of the three-phase inverter bridge correspondingly. According to the through physical separation-type Z-source inverter with high booster multiple, no coupling relationship exists between a booster factor and an inverter factor, the through duty ratio is independently controlled, and the booster multiple which can be realized is high.

Description

technical field [0001] The invention relates to a Z-source inverter, which belongs to a power electronic conversion device. Specifically, it is a straight-through physically separated Z-source inverter with a high boost multiple and no coupling relationship between a boost factor and an inverter factor. Background technique [0002] Literature (F. Z. Peng, Z-source inverter, IEEE Trans. Ind. Appl., 2003, 39(2): 504- 510) proposed the original Z-source inverter, its structure is as attached figure 1 As shown, by adding an X-shaped impedance network between the DC power supply and the inverter bridge, the performance of the inverter is improved. Compared with the traditional voltage source and current source inverters, it has the following excellent characteristics: (1) It has the ability of step-up and step-down at the same time, and the multiple of step-up and step-down is determined by the step-up factor and the inverter factor; (2) In the SVPWM control algorithm, it is all...

AI Technical Summary

Problems solved by technology

However, the original Z-source inverter has the following defects: 1. The actual insertable straight-through vector cannot be more than the zero vector in one switching cycle, resulting in a very limited actual achievable boost multiple

2. There is an interdependent relationship between the boost factor and the inverter factor, and the two ebb and flow. The red text is changed to: cannot be increased at the same time, which reduces the flexibility of the control strategy

[0003] Specifically, the original Z-source inverter has the following defects: The boost of the Z-source inverter is completed by adding a through vector, and its boost multiple is related to the percentage of the added through vector. The greater the pressure

However, these two improvements to the original Z-source inverter need to add a large number of additional power devices, and these two improvements still have not released the coupling relationship between the boost factor and the inverter factor, and have not broken through the direct vector ratio. Less than the limitation of zero vector, the actual achievable boost multiple is still very limited

Images