A Voltage Equalization Protection Circuit and Diode Clamp Multilevel Topology Device

Abstract

The invention discloses a voltage sharing protection circuit which is applied in diode clamping multi-level topology. The voltage sharing protection circuit comprises a filtering circuit, a first clamping circuit and a first inversion circuit, wherein two ends of the first clamping circuit are connected with a voltage sharing module, when a group of internal and external power switch devices in the first inversion circuit are connected and another group of internal and external power switch devices are disconnected, connecting points between the internal and external power switch devices disconnected are effectively clamped at the neutral-point voltage of a busbar, so that the disconnected power switch devices can effectively share the voltage of the busbar, and solving the overvoltage or voltage imbalance problem of the power switch devices; and in addition, the voltage sharing protection circuit is simple in structure, has good voltage sharing effect, and a system comprising the voltage sharing protection circuit works more reliably and more stably.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a voltage equalizing protection circuit and a diode clamp multilevel topology device. Background technique [0002] Insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, referred to as IGBT), as the main power switching device, is used in power electronic devices using diode-clamped three-level topology, such as medium and high voltage inverters, wind power, photovoltaic inverters, SVG, UPS etc. Diode-clamped three-level topology circuit such as figure 1 As shown, T1, T2, T3, and T4 are IGBTs, T1 and T4 are referred to as outer tubes, T2 and T3 are referred to as inner tubes, D1, D2, D3, and D4 are freewheeling diodes connected in parallel with IGBTs, and D5 and D6 are clamps bit diode. The three-level topology circuit clamped by the pole tube has three switching modes: T1 and T2 are turned on, T3 and T4 are turned off, and the output voltage Uout is ...

AI Technical Summary

Problems solved by technology

[0006] Embodiments of the present invention provide a voltage equalization protection circuit and a diode-clamped multilevel topology device. The voltage equalization protection circuit is applied to a diode-clamped multi-level topology in order to solve the problem of unbalanced voltage in a diode-clamped multi-level topology. problems, improving the lifetime of electronic devices in multilevel circuits

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