Asymmetric bidirectional direct-current converter appropriate for high voltage situation

Abstract

The invention relates to an asymmetric bidirectional direct-current converter appropriate for a high voltage situation. When energy is transmitted from a first power source (V1) to a second power source (V2), a port a and a port b of a single-pole double-throw switch (S) are connected, a first auxiliary switch (Qs1) and a second auxiliary switch (Qs2) are both in a turn-off state, wherein the auxiliary switch is formed by connecting a diode and a switch tube in series, a circuit can be formed by connecting primary sides of two single active bridge type direct-current converters in parallel and connecting secondary sides of the two single active bridge type direct-current converters in series, and the circuit is appropriate for a high output voltage situation. When the energy is transmitted from the second power source (V2) to the first power source (V1), the port a and a port c of the single-pole double-throw switch (S) are connected, the first auxiliary switch (Qs1) and the second auxiliary switch (Qs2) are in an on-off state, eight switch tubes (Q1-Q8) of the primary sides are in a turn-off state, the circuit can be regarded as a half bridge type direct-current converter which is particularly appropriate for the high voltage situation in which the energy needs to be transmitted in an asymmetric bidirectional mode, such as wind power generation on the sea.

Description

technical field [0001] The invention relates to a bidirectional DC converter suitable for high-voltage occasions, belongs to the technical field of power electronic converters, and is mainly used in new energy power generation occasions. Background technique [0002] Offshore wind power generation is widely valued by countries all over the world because it does not occupy land land, high wind speed, and abundant wind energy resources. At present, most offshore wind farms use AC power generation systems, and offshore wind farms with DC power generation system structures technology is gaining more and more attention, such as figure 1 shown. The DC power generation system has the following advantages: 1) Using a high-voltage and high-frequency DC boost converter to replace the power frequency step-up transformer can greatly reduce the weight and volume of power electronic devices in the power generation system, reduce the requirements for offshore infrastructure, and reduce 2...

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Problems solved by technology

However, the energy required for the start-up of the wind turbine is very small compared with the energy emitted during normal operation, and the existing bidirectional converters are generally used together with energy storage devices such as batteries, and the energy transmitted in both directions of the bidirectional converter is basically Therefore, the existing bidirectional converter is not suitable for the special occasion of DC system offshore wind power, and the "cost performance" is not high

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