Negative-damping low-frequency oscillation and forced power oscillation distinguishing method

A technology of forced power oscillation and low frequency oscillation, which is applied to instruments, measuring devices, measuring electricity, etc., can solve problems such as suppressing oscillation, and achieve the effects of strong practicability, fast calculation speed, and simple and easy calculation method.

Active Publication Date: 2013-02-27
ECONOMIC & TECH RES INST OF HUBEI ELECTRIC POWER COMPANY SGCC +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] At present, when low-frequency oscillation occurs in the power grid, there is no way to make a timely and effective judgment on the mechanism of the oscillation, and it is often difficult to quickly and timely suppress the oscillation by relying on the experience of dispatchers to take measures

Method used

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  • Negative-damping low-frequency oscillation and forced power oscillation distinguishing method
  • Negative-damping low-frequency oscillation and forced power oscillation distinguishing method
  • Negative-damping low-frequency oscillation and forced power oscillation distinguishing method

Examples

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Effect test

Embodiment 1

[0053] Such as figure 1 As shown, a negative damping low-frequency oscillation and forced power oscillation discrimination method, the method includes the following steps:

[0054] a. in there generator and In the AC interconnected grid with two loads, the two ends of each generator-grid connection branch and load-grid connection branch are installed with synchronized phasor measurement unit PMU; figure 2 As shown, in the connection branch between the generator and the grid, A1, A2, ..., AM are PMU monitoring points on the generator side, B1, B2, ..., BM are PMU monitoring points on the grid side; in the connection branch between the load and the grid Among them, D1, D2, ..., DN are PMU monitoring points on the load side, and C1, C2, ..., CN are PMU monitoring points on the grid side;

[0055] b. When the wide-area measurement system monitors the dominant oscillation frequency of the oscillation in the power grid , active power oscillation amplitude , the number of c...

Embodiment 2

[0069] when attached image 3 When low-frequency oscillation occurs in the 4-machine 2-zone system shown, a method for discriminating negative damped low-frequency oscillation and forced power oscillation of the present invention is used to discriminate the mechanism of low-frequency oscillation. The steps are as follows:

[0070] a. In the attached picture image 3 In the shown AC interconnected grid, there are 4 generating sets G1, G2, G3, and G4 and 2 loads PL1 and PL2. 4 generating sets are respectively connected to nodes 1, 2, 3 and 4, and 2 loads are connected to nodes 7 and 9 respectively. All nodes and branches in the power grid are equipped with PMU equipment. After the oscillation occurs, the data is synchronously transmitted to the wide-area measurement system of the power grid dispatching center.

[0071] b. When the wide-area measurement system detects that low-frequency oscillation occurs in the power grid and meets the set alarm threshold, it will immediately ...

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Abstract

The invention discloses a negative-damping low-frequency oscillation and forced power oscillation distinguishing method, relating to scheduling automation of a power system and safety operation of a power grid. The method comprises the following steps of: calculating energy flow direction factors of all generators and load branches based on data acquired by a power grid wide area measuring system (WAMS) when negative-damping low-frequency oscillation or forced power oscillation happens in the power grid; judging whether a definite external disturbance source exists in the power grid; if the definite external disturbance source exists, judging that a low-frequency oscillation mechanism is based on forced power oscillation; and if no external disturbance source exists, judging that the low-frequency oscillation mechanism is based on negative-damping low-frequency oscillation. The negative-damping low-frequency oscillation and forced power oscillation distinguishing method has the advantages that the basis is provided for the power dispatching department to take corresponding measures for rapidly inhibiting oscillation when the power grid has low-frequency oscillation; in addition, the calculating method is simple and feasible, high in calculating speed, capable of meeting the requirement of a real-time oscillation judgment mechanism of the power grid and strong in practicability.

Description

technical field [0001] The invention relates to the dispatching automation of the power system and the safe operation of the power grid, and more specifically relates to judging whether the low-frequency oscillation of the power grid belongs to negative damping low-frequency oscillation or forced power oscillation. Background technique [0002] Under the disturbance of the power system, the relative swing between the rotors of the motor will occur and cause continuous oscillation in the absence of damping. The oscillation frequency ranges from 0.1 to 2.5Hz, so it is called low-frequency oscillation. As for the mechanism of low-frequency oscillation, the theoretically perfect one is the most widely used negative damping theory, F. Demello et al. used the concept of damping torque in 1969 to study the mechanism of low-frequency oscillation in a single-machine-infinity system. They believed that the cause of low-frequency oscillation was due to the negative damping effect of th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/00
Inventor 杨东俊许汉平胡婷黄家祺罗纯坚
Owner ECONOMIC & TECH RES INST OF HUBEI ELECTRIC POWER COMPANY SGCC
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