Centralized energy consuming device and control method thereof

Abstract

The invention discloses a centralized energy consuming device. The centralized energy consuming device consists of an energy-consuming branch and a energy consuming resistor; the energy consuming branch is formed by the series connection of at least one energy consuming sub-module with the same direction; the head end of the series connection is connected to a high potential electrode of a directcurrent line; the energy consuming resistor is centralizedly arranged and connected in series with the energy consuming branch; one end of the energy consuming resistor is connected to a tail end of the energy consuming branch, and the other end is connected to a low potential electrode of the direct current line. The invention also includes a control method of the centralized energy consuming device; when the direct current line voltage rises, the direct current voltage control can be realized by turning on or off power semiconductor switching devices in the energy consuming sub-module in successively, so as to realize flexible input and flexible exit of the energy consuming resistor. The centralized energy consuming device is cost-effective, highly reliable and easy to implement.

Description

Technical field [0001] The invention belongs to the technical field of high-power power electronic converters, and specifically relates to a centralized energy consumption device and a control method. Background technique [0002] In the high-voltage direct current transmission system, centralized energy-consuming devices are vital equipment. Centralized energy-consuming devices are mainly used in the application scenarios of island power supply. If the generating end is an inertial power source similar to wind power, when the receiving end fails, because the power cannot be sent, 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 used is to directly connect power semiconductor devices in series. When the DC voltage is too high, the resistor is controlled by the power electronic device. The input of the resistor will reduce the DC v...

AI Technical Summary

Problems solved by technology

The centralized 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

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