A centralized energy consumption device and its control method

Abstract

The invention discloses a centralized energy consumption device. The device is composed of an energy consumption branch and an energy consumption resistor. The energy consumption branch is composed of at least one energy consumption sub-module connected in series in the same direction. The first end of the series connection is connected to the The high-potential electrodes of the DC line are connected; the energy-dissipating resistors are centrally arranged and connected in series with the energy-consuming branches, one end of the energy-dissipating resistors is connected to the tail end of the energy-consuming branches, and the other end is connected to the low-potential electrodes of the DC lines; The invention also includes a control method for a centralized energy-consuming device. When the DC line voltage rises, the power semiconductor switching devices in the energy-consuming sub-modules can be turned on or off in sequence to realize DC voltage control and realize flexible input of energy-consuming resistors. and flexible exit, the device has high cost performance, high reliability, and is easy to implement.

Description

technical field [0001] The invention belongs to the technical field of high-power electric current conversion, and in particular relates to a centralized energy consumption device and a control method. Background technique [0002] In HVDC power transmission system, centralized energy consumption device is a crucial equipment. 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, 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 inpu...

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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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