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Reclosing method and system based on AC-DC interconnection system

An interconnected system, AC and DC technology, applied in the AC and DC field, can solve the problem of not being able to obtain the best reclosing time and so on

Active Publication Date: 2021-05-14
NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] In view of the above analysis, the embodiment of the present invention aims to provide a reclosing method and system based on an AC-DC interconnection system to solve the problem in the prior art that the optimal reclosing time under an AC-DC interconnection system cannot be obtained

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  • Reclosing method and system based on AC-DC interconnection system
  • Reclosing method and system based on AC-DC interconnection system

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Embodiment 1

[0054] A specific embodiment of the present invention discloses a reclosing method based on an AC-DC interconnection system, the flow chart is as follows figure 1 As shown, the method includes the following steps:

[0055] Step S1: When a short-circuit fault is detected in the AC-DC interconnection system, start a protection action and determine the location of the fault point;

[0056] Preferably, the short-circuit fault in step S1 is a single-phase-to-ground fault or a three-phase fault.

[0057] The distance protection device is used to select the fault phase, and the type of the short-circuit fault is determined according to the fault phase selection result; the distance protection device is also used to determine the location of the fault point.

[0058] The starting protection action described in step S1 includes: when the short-circuit fault is a single-phase ground fault, the circuit breaker trips a single phase; when the short-circuit fault is a three-phase fault, th...

Embodiment 2

[0134] Embodiment 2 of the present invention discloses a reclosing system based on an AC-DC interconnection system, including: a fault detection and positioning module, used to initiate a protection action when a short-circuit fault occurs in the AC-DC interconnection system is detected, And determine the location of the fault point; the optimal reclosing time determination module is used to collect the angular velocity of the generator rotor and the power angle of the generator at each moment in real time from the start protection action moment; and at each moment, judge the power generation Whether the angular velocity of the machine rotor is equal to the angular velocity of the rotor of the best closing generator, and whether the power angle of the generator is equal to the best closing generator power angle, if they are all equal, the current moment is taken as the best reclosing time; the relay protection device , used to control the reclosing of the circuit breaker at the...

Embodiment 3

[0140] Specific embodiment 3 of the present invention discloses a specific implementation process of an acquisition method for optimal reclosing time in an AC-DC interconnection system, using image 3 A high-voltage DC transmission system model is built on the RT-LAB platform, and the sending end system transmits power to the receiving end through a 500kV DC line. The HVDC rated voltage is 500kV, and the HVDC rated transmission capacity is 1000MW. The system frequency is 50Hz, the active power absorbed by the load is 1200MW, the reactive power absorbed by the load is 30Mvar, the total length of the AC line is 100km, the positive sequence resistance of the AC line is 0.0431Ω / km, and the positive sequence reactance of the AC line is 0.5500Ω / km. Simulation process such as Figure 6shown. A fault occurs at point a, protection action occurs at point b, the circuit breaker trips, and reclosing is activated at point c, the system recloses to a permanent fault, reclosing trips the...

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Abstract

The invention relates to a reclosing method and system based on an AC-DC interconnection system, belongs to the technical field of alternating current and direct current, and solves the problem that the optimal reclosing time of the AC-DC interconnection system cannot be obtained in the prior art. The reclosing method based on an AC-DC interconnection system comprises the following steps that when detecting that a short circuit fault occurs in the alternating current and direct current interconnection system, protection action is started, and the position of a fault point is determined; by starting from the moment of starting the protection action, a generator rotor angular speed and a generator power angle at each moment are collected in real time; at each moment, whether the generator rotor angular velocity is equal to the optimal closing generator rotor angular velocity and whether the generator power angle is equal to the optimal closing generator power angle are judged, and if generator rotor angular velocity is equal to the optimal closing generator rotor angular velocity and the generator power angle is equal to the optimal closing generator power angle, the current moment serves as the optimal reclosing time; and the circuit breaker is controlled to coincide at the optimal reclosing time. According to the method, the optimal reclosing time can be determined, and the circuit breaker is controlled to be overlapped at the optimal reclosing time.

Description

technical field [0001] The invention relates to the field of AC and DC technologies, in particular to a reclosing method and system based on an AC and DC interconnection system. Background technique [0002] At present, the automatic reclosing system is widely used in the power system and plays an important role in improving the stability of the interconnected grid and the reliability of power supply. Choosing an inappropriate time to start reclosing in the AC / DC hybrid system may lead to cascading failures, which will lead to system transient instability and even power outages. Therefore, it is urgent to carry out research on the optimal closing time of the AC-DC interconnection system. [0003] Aiming at the calculation method of optimal reclosing time of power system, scholars have carried out relevant research, and the methods are mainly divided into the setting method based on the minimum intermittent time and the setting method based on transient stability. The setti...

Claims

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Application Information

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IPC IPC(8): H02H3/06H02J3/36
CPCH02H3/063H02J3/36Y02E60/60
Inventor 马静周晓东张家铭刘晨
Owner NORTH CHINA ELECTRIC POWER UNIV (BAODING)