Chain type energy consumption device and control method thereof

Abstract

The invention discloses a chain type energy consumption device. The chain type energy consumption device is composed of an energy consumption branch and energy consumption resistors, wherein the energy consumption branch is formed by connecting at least one energy consumption sub-module in the same direction, and the head end of the serial connection is connected with a high potential electrode ofa direct current circuit; the energy consumption resistors are arranged in a centralized mode and are connected in series with the energy consumption branch; one ends of the energy consumption resistors are connected with the tail end of the energy consumption branch, and the other ends are connected with the low potential electrode of the direct current circuit; and the energy consumption sub-module is composed of a first power semiconductor switch device, a diode and a direct-current capacitor. The invention further provides a control method of the chain type energy consumption device; whenthe voltage of the direct current circuit rises, direct-current voltage control can be realized by sequentially conducting or turning off power semiconductor switching devices in the energy consumption sub-module, so that the flexible input and the flexible exit of the energy consumption resistors can be realized; and the device is high in cost performance, high in reliability and easy to realize.

Description

technical field [0001] The invention belongs to the technical field of high-power electric current conversion, and in particular relates to a chain type energy consumption device and a control method. Background technique [0002] In HVDC power transmission system, chain energy consumption device is a crucial equipment. The chain-type energy consumption device is mainly used in the application scenario of island power supply. If the power generation end is an inertial power source similar to wind power, when the power receiving end fails, the power will not be sent out, and the energy will be accumulated on the DC side, resulting in damage to the DC transmission line. The voltage rises, which will endanger the safe operation of the equipment. [0003] In the prior art, the method adopted is to directly connect the power semiconductor devices in series. When the DC voltage is too high, through the control of the power electronic device, a resistor is put in. The input of the...

AI Technical Summary

Problems solved by technology

The chain-type energy consumption device is mainly used in the application scenario of island power supply. If the power generation end is an inertial power source similar to wind power, when the power receiving end fails, the power will not be sent out, and the energy will be accumulated on the DC side, resulting in damage to the DC transmission line. The voltage rises, causing harm to the safe operation of the equipment

[0003] In the prior art, the method adopted is to directly connect the power semiconductor devices in series. When the DC voltage is too high, through the control of the power electronic device, a resistor is put in. The input of the resistor will reduce the DC voltage. When the energy consumption speed of the resistor exceeds the DC voltage The speed at which the side accumulates energy, the DC voltage will drop. At this time, turn off the resistance discharge circuit, the DC voltage will rise again, and repeatedly turn on and off the resistance branch, forming the effect of hysteresis control. The main problem of this method is The problem is that when turning off, it is difficult to ensure consistency because multiple power semiconductor switching devices are turned off at the same time. Once the shutdown is not synchronized, the slow-turning device or the fast-turning-off device will be damaged due to overvoltage; Moreover, the high-speed on and off state switching will also result in a large voltage and current change rate, resulting in magnetic field interference

In addition, in the prior art, each sub-module includes a large number of power semiconductor devices, and the cost is relatively high

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