Power flow controller with failure current limiting function

Abstract

The invention discloses a power flow controller with a failure current limiting function. When a power grid does not fail, the power flow controller controls current on a current limiting inductor by a current transformer and regulates equivalent impedance flowing into the power grid, thereby controlling the transmission power of the power grid, and compensates the harmonic waves and reactive power of transmission current by the current transformer; and when the power grid fails, the current limiting inductor is directly connected in series to the power grid to function in failure current limiting, and simultaneously, the power flow controller also can control the current transformer to discharge the current limiting inductor and control the current of the current limiting inductor to better current limiting effects, and can perform steady current limiting by a current limiting bypass, with the current limiting inductor, of a protective circuit to better failure current limiting effects.

Description

technical field [0001] The invention relates to a power flow controller with fault current limiting function. Background technique [0002] Power flow control and fault current limiting are two core technical problems faced by the transmission network. At present, there are mainly two types of power flow controllers. One is to change the equivalent impedance of the line, such as figure 1 The U.S. Patent US00542495 "power flow control of transmission lines" shown in Fig. figure 2 Patent WO 9605642A1 "Universal fast power flow controller" is shown. These two types of power flow controllers can effectively control the flow of grid power, but they are powerless against grid faults, and short-circuit faults in the grid can even cause devastating damage to these devices themselves. image 3 The Chinese patent 200620069650.2 "unified power flow controller with short-circuit current limiting function" uses a variable impedance transformer with overcurrent magnetic circuit satura...

AI Technical Summary

Problems solved by technology

Both types of power flow controllers can effectively control the flow of grid power, but they are powerless against grid faults, and short-circuit faults in the grid can even cause devastating damage to these devices themselves

image 3 The Chinese patent 200620069650.2 "unified power flow controller with short-circuit current limiting function" uses a variable impedance transformer with overcurrent magnetic circuit saturation characteristics to achieve fault current limiting, but this circuit cannot protect the device itself. may cause damage to the power electronic devices of the device itself

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