Single-stage boosting inverter with tap inductor

Abstract

The invention discloses a single-stage boosting inverter with a tap inductor, which is shown in a figure described in the specification. The inverter comprises an inversion bridge (B) and a passive network. The passive network comprises an inductor (L), capacitors (C1 and C2), diodes (D1, D2 and D3) and the tap inductor (Lt). A first winding (N1) and a second winding (N2) of the tap inductor (Lt) are connected in series positively. According to the inverter disclosed by the invention, energy is stored in the tap inductor (Lt) by utilizing an ended zero vector state forbidden in the traditional voltage type inverter; the energy is combined with energy supplied by an input power supply in a non-ended zero vector state; and the combined energy is transmitted together to a middle bus so that the voltage of the bus is boosted. Therefore, the inverter can output alternating-current voltage, an amplitude value of which is higher than that of input voltage (Vi); the inverter can satisfy boosting requirements in different application situations by configuring the turn ratio of the tap inductor (Lt); and in the event of being applicable to an alternating-current input situation, the inverter can also realize a power factor correction (PFC) function.

Description

technical field [0001] The invention relates to a single-stage step-up inverter with a tapped inductor, which is especially suitable for a motor drive system in which a DC bus needs to be powered by a low-voltage step-up and a new energy power generation inverter application adapting to a large input voltage variation range. Background technique [0002] A traditional voltage source inverter such as the attached figure 1 As shown, there are usually the following limitations or deficiencies: [0003] (1) The AC load must be inductive or have to be connected in series with the AC power supply to enable the voltage source inverter to work normally. [0004] (2) The AC output voltage is limited to be lower than but not higher than the DC bus voltage. Therefore, for DC / AC power conversion, the traditional voltage source inverter is a step-down inverter. For DC / AC power conversion applications with low DC voltage and high AC output voltage, an additional DC / DC boost converter is...

AI Technical Summary

Problems solved by technology

Since the capacitor voltage is 0 at start-up, there is a large inrush current at start-up, and it is easy to cause resonance during the start-up process, resulting in a large inrush current and inrush voltage, which may damage the inverter

[0016] (2) The bus voltage of the inverter bridge is lower than the capacitor voltage, and the voltage level of the capacitor cannot be fully utilized. If it is a high-voltage application, a high-voltage capacitor is required, and the volume is large

The voltage will drop, and the modulation algorithm of the inverter must consider the influence of voltage changes, which increases the complexity of inverter control

[0017] (3) Passive components are required to be symmetrical, which increases the difficulty of design, and capacitor failure is catastrophic for this system circuit

[0021] (3) The input current is intermittent. If it is used in the occasion where the input current is continuous, an LC energy storage unit must be added to the input side

There are few published studies on implementing PFC function in impedance source inverters

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