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Method for evaluating system damping ratio based on number of power oscillation times

A technique for evaluating system and power oscillations, which is applied to the evaluation of the damping ratio of the power system. It is possible to evaluate the system damping ratio based on the number of power oscillations. Correspondence between the number of disturbances and the damping ratio of the system

Active Publication Date: 2015-03-25
STATE GRID CORP OF CHINA +2
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the theoretical analysis of the corresponding relationship between the effective disturbance times of the tie line and the system damping ratio is not given in the paper, and it is difficult to quantitatively determine the corresponding relationship between the effective disturbance times and the system damping ratio

Method used

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  • Method for evaluating system damping ratio based on number of power oscillation times
  • Method for evaluating system damping ratio based on number of power oscillation times
  • Method for evaluating system damping ratio based on number of power oscillation times

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Experimental program
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Effect test

Embodiment 1

[0040] Depend on figure 1 It can be seen that a method for evaluating the damping ratio of a system based on the number of power oscillations includes the following steps:

[0041] (a) A wide-area measurement system is installed in an interconnected power grid with H areas, L inter-area tie lines, N branches, n nodes, and m generator nodes among them. The power grid is installed on all branches A synchronized phasor measurement unit is set;

[0042] (b) Obtain the voltage amplitude and phase angle of all nodes and the information of effective disturbance times in the wide-area measurement system, and obtain the parameters of each generator in the interconnected grid and the parameters of all lines through the power system analysis comprehensive program software, and convert the above information and parameters to generate a small disturbance linearization equation for the interconnected grid;

[0043] Firstly, it is explained that in the present invention, the generator bus,...

Embodiment 2

[0138] Carry out the test of the present invention on 4 machines 11 nodes standard test example, its network structure diagram is as follows figure 2 shown. In the study, we focus on a certain mode with weak damping in the interconnected grid, that is, we mainly focus on the inter-regional oscillation mode with the weakest damping in the 4-machine 11-node interconnected grid, and adjust the PSS so that the damping of the other oscillation modes is relatively high, and the oscillation mode of the interconnected grid is obtained As shown in Table 1.

[0139] Table 1 Oscillation mode of 4-machine 11-node interconnected grid

[0140]

[0141] The external impact disturbance area F obeys N(μ,σ 2 ), take μ=0.5, σ 2 = 0.08, the node position distribution of the impact disturbance obeys the average distribution, and the effective disturbance times of the two tie lines between area 1 and area 2 in the frequency range of [0.50Hz, 0.55Hz] on the 4-machine 11-node interconnection g...

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Abstract

The invention discloses a method for evaluating a system damping ratio based on the number of power oscillation times. According to the method, a small interference linearity equation of the interconnected network is generated based on data provided by a wide domain measuring system and power system analysis comprehensive program software, and the equation is solved to obtain time domain expressions of the power oscillation of various branches; the number of effective disturbance times of connecting lines between two domains within the domain oscillation frequency range and the relation of the theoretical ratio of the total number of effective disturbance times of the interconnected network and the damping ratio among the domains are obtained according to the time domain expressions of the power oscillation of the branches and an effective disturbance judging method; the number of effective daily disturbance times among the domains and the number of effective daily disturbance times of the interconnected network are obtained through the wide domain measuring system, and the actual ratio of the number of effective daily disturbance times among the domains and the number of effective daily disturbance times of the interconnected network is worked out; a curve chart corresponding to the relation is drawn, and the evaluation value of the damping ratios among the areas is obtained. The value of the damping ratio of the system and the changing situation can be evaluated according to WAMS historical data, and reference data are provided for operation workers.

Description

technical field [0001] The invention relates to the field of power system operation and control, in particular to the evaluation of the damping ratio of the power system, and proposes a method for evaluating the system damping ratio based on the number of power oscillations. Background technique [0002] With the interconnection of regional power grids, active power oscillation has gradually become one of the main threats to the safe and stable operation of large interconnected power grids. The increasing size of the grid grid and the wide application of fast excitation and electro-hydraulic servo speed control devices have greatly increased the risk of active power oscillations in the interconnected grid. probability of a power outage. Therefore, the active power oscillation problem of large power grids is a difficult problem that must be faced in the development of domestic and foreign power grids. For operation dispatchers, monitoring and predicting changes in the grid ...

Claims

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Application Information

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IPC IPC(8): G01R31/00
Inventor 许汉平陈伟彪杨东俊刘子全魏聪文劲宇
Owner STATE GRID CORP OF CHINA
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