Active neutral-point-clamped three-level circuit and control method thereof

Abstract

The invention discloses an active neutral-point-clamped three-level circuit and a control method thereof. The active neutral-point-clamped three-level circuit comprises a direct-current positive port, a direct-current neutral point, a direct-current negative port, an alternating-current output port and a bridge arm circuit arranged between the direct-current positive port and the direct-current negative port. The bridge arm circuit comprises four full-control switches, two half-control switches and six diodes; the control method comprises the following steps: controlling four full-control switches to work in a high-frequency switch working state with the same frequency as a carrier wave, and controlling two half-control switches to work in a power-frequency switch working state with the same frequency as a signal wave, so that an alternating-current output port of the active neutral-point-clamped three-level circuit outputs a pulse width modulation signal; according to the active neutral-point-clamped three-level circuit and the control method thereof, a full-control switch is replaced by a half-control switch, so that the cost of the active neutral-point-clamped three-level circuit is reduced, and the current output capability when the voltage of an output port is relatively low is improved.

Description

technical field [0001] The present application relates to the technical field of power electronics, in particular to a control method of a three-level converter. Background technique [0002] In 1980, A. Nabae of Nagaoka University of Science and Technology in Japan proposed a diode neutral point clamp (NPC) topology converter at the IEEE-IAS annual meeting. Such as figure 1 As shown, because the NPC topology adopts the method of connecting two busbars in series, the busbar voltage and AC output voltage can be increased, and the switching loss of semiconductor switching devices can be reduced; therefore, the NPC topology has been widely used. [0003] In 2001, Professor T.Bruckner, a German scholar, proposed the topology of the active neutral point clamped three-level (ANPC) for the first time at the IEEE-PESC conference. Such as figure 2 As shown, because the ANPC topology adds two semiconductor switches with active neutral point clamping compared with the NPC topology,...

AI Technical Summary

Problems solved by technology

[0004] The ANPC topology converter has the disadvantages of high cost, and when the output voltage is low, the heat generated by the semiconductor switch inner tube is large.

The traditional NPC topology needs to use 4 semiconductor fully-controlled switches for each phase converter, and the ANPC topology requires 6 semiconductor fully-controlled switches for each phase converter. Therefore, the ANPC topology increases the cost of semiconductors, resulting in low cost performance. In addition, When the AC side voltage of the converter circuit is low, the semiconductor switches T2 and T3 bear more conduction loss, and the overcurrent capability of the semiconductor full control switch is weak

Images