Dynamic power flow control device with wave trap and control method for controllable transformer

Abstract

The invention discloses a dynamic power flow control device with a wave trap for a controllable transformer. The dynamic power flow control device consists of the controllable transformer, a power unit, a measurement and control module, a bypass switch, the wave trap, an input voltage transformer, an output voltage transformer and an output current transformer. In a dynamic power flow control method, a power electronic switch rapidly switched on and switched off controls the on-off of a tapping point of an output side / secondary side of the controllable transformer; a direct current signal is injected into a frequency-doubled or frequency-multiplied signal in a pulse width modulation signal, and the amplitude of the direct current signal and the amplitude and initial phase of the frequency-doubled or frequency-multiplied signal are changed, thereby changing the phase and amplitude of output voltage of the controllable transformer and realizing the regulation of active power and reactive power; and the wave trap filters triple frequency harmonics or odd harmonics, corresponding to frequency multiplication modulation, of the output voltage of a dynamic power flow controller of the controllable transformer to avoid the distortion of the output voltage. The device and the method have the characteristics of low cost and high dynamic power flow control reliability.

Description

technical field [0001] The invention relates to the technical field of flexible power transmission, in particular to a dynamic power flow control device of a controllable transformer with a wave trap and a control method thereof. Background technique [0002] With the interconnection of large-scale power systems and the use of various new equipment, while making power generation and transmission more economical and efficient, the scale and complexity of the power system have also increased, and the possibility of the power grid operating on the edge of the stability limit has also greatly increased. . Therefore, the flexibility of power grid operation, controllability of power flow and stability of power grid have become more and more urgent problems to be solved. [0003] Therefore, the demand generated by the operating pressure of the transmission system in the 21st century can be summarized into the following three aspects: [0004] (1) Increase power transmission capac...

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Problems solved by technology

[0008] Although the current FACTS technology has many of the above advantages, it also has great limitations: the cost of the FACTS device is high, and it is difficult to popularize and apply; there are adverse effects between FACTS and power equipment and other controllers; the loss of the FACTS device itself is large ; The complex control structure of the FACTS device and the requirements for corresponding auxiliary equipment such as communication facilities put forward stricter requirements for the operation and control of the power grid; additional problems caused by device failure; system stability problems caused by series connection etc. make its application in the power grid very limited

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