Power grid alternating current flexible loop closing control device and control method thereof

A ring control and flexible technology, applied in the direction of circuit device, emergency treatment AC circuit layout, AC network circuit, etc., can solve the problems of high short-circuit fault current level, low equipment utilization rate, high equipment cost, etc., and improve the reliability of distribution network , increase the service life, reduce the effect of mechanical wear

CN113991670AInactive Publication Date: 2022-01-28NANJING HEXI ELECTRIC CO LTD +2
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2022-01-28
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a power grid alternating current flexible loop closing device and a control method thereof. The device is a series-parallel connection device and comprises a series connection coupling unit, a parallel connection coupling unit, other bypass switch circuits and a loop closing main controller. After a loop closing instruction is received, the loop closing control device is set to work in a voltage control mode, and when the amplitude and the phase of the output voltage of the device side coincide with the other section, the system enters a loop closing state. And after entering a loop closing state, the device works in a PQ control mode. Before loop closing is quitted, P and Q of the device are gradually reduced to zero, then the access switches are sequentially disconnected, and the loop closing process is finished. The device has the advantages that the device is simple in structure, low in cost and high in efficiency, the voltage amplitude and phase of a loop closing point can be adjusted online, active and reactive power flow between loop closing areas can be adjusted online in a bidirectional mode, and the power factor of the loop closing areas is kept at the optimal value. Flexible power supply transfer between the distribution networks and rapid exit during a fault can be realized, and the load rate and the load balance of a distribution network power supply area are improved.
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Description

technical field

[0001] The invention belongs to the technical field of distribution network optimization operation control, and in particular relates to an AC flexible loop closing control device for power grid and a control method thereof. Background technique

[0002] my country's distribution network usually adopts the method of "closed-loop design, open-loop operation", that is, when the power grid is closed, the network structure can be optimized by adjusting the state of the contact switch and the segment switch, so as to maintain the efficient and reliable operation of the distribution network and realize the fault area. Quick power restoration. However, this method of realizing closed-loop operation through tie switches cannot achieve flexible power control because the power flow is naturally distributed with impedance. When closing the loop, if there is a voltage difference and a phase difference between the two sides of the loop closing point, not only will a circu...

Examples

Embodiment Construction

[0043] The technical solution of the present invention will be further specifically described below in conjunction with the accompanying drawings.

[0044] Step 1, establish the system model of the grid AC flexible loop closing device, such as figure 1 shown. The device in this embodiment includes a series coupling unit, a parallel coupling unit, a bypass switch circuit, a ring-closing main controller and two groups of access switches, wherein the series coupling unit has two AC ports and one DC port, and its two AC ports It is directly connected in series between the two AC output ports of the device, and is connected in parallel with the internal bypass switch; the parallel coupling unit has an AC port and a DC port, and its AC port is connected to one of the AC ports of the series coupling unit, and its DC The port is connected to the DC port of the series coupling unit, and connected to the common DC bus to form the DC output port of the device. Two sets of access switch...