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An Online Voltage Stability Discrimination System for AC/DC Hybrid System

An AC/DC hybrid and voltage stabilization technology, which is applied in the direction of AC network voltage adjustment, etc., can solve the problems that it is difficult to apply the online voltage stability monitoring system, does not consider the short-circuit impact, and the static voltage stabilization method cannot be accurately simulated, etc., to achieve simplified online calculations The effect of scale and speed-up

Active Publication Date: 2016-03-02
STATE GRID CORP OF CHINA +2
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

For the first type of fault, since the short-circuit impact is not considered, the situation is relatively simple; it is similar to the voltage instability caused by the slow increase of load considered in static voltage stability. The static voltage stabilization method cannot accurately simulate the response of loads, generators, etc., but some types of load responses and generator constraints can also be considered in static voltage stabilization
At present, the commonly used static voltage stability indicators include sensitivity index, load margin index, Jacobian matrix minimum singular value index, local voltage stability L index, etc., and have achieved good static voltage stability evaluation results, but these methods need to be carried out to varying degrees. It is difficult to apply to the online voltage stability monitoring system that requires fast calculation

Method used

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  • An Online Voltage Stability Discrimination System for AC/DC Hybrid System
  • An Online Voltage Stability Discrimination System for AC/DC Hybrid System
  • An Online Voltage Stability Discrimination System for AC/DC Hybrid System

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Embodiment 1

[0045] Embodiment 1 provided by the present invention is an embodiment of an online voltage stability judgment system for an AC / DC hybrid system, and its structural diagram is as follows figure 2 As shown, specifically, the real-time data acquisition module collects the resistance R, reactance X, admittance B, and active power P of the transmission line in real time through the PMU (PhasorMeasurementUnit, vector measurement unit) B , reactive power Q B and line sending bus voltage U A and other parameters.

[0046] Depend on figure 2 It can be seen that the embodiment of the system also includes an event occurrence monitoring module.

[0047] One end of the event monitoring module is connected to the real-time data acquisition module, and the other end is connected to the online voltage stability evaluation index calculation module. trip, AC system short-circuit fault, etc.), first judge whether there is a short-circuit fault impact. If there is a short-circuit fault im...

Embodiment 2

[0065] Embodiment 2 provided by the present invention takes the actual AC and DC system as the prototype, and constructs a calculation example system such as Figure 5 As shown, the calculation example includes AC and DC transmission channels and a clear relationship between transmission and reception. A typical AC / DC hybrid system is formed at Bus1 and Bus3, the load is mainly distributed at Bus6 and Bus8, and the load power factor is 0.95.

[0066] First, according to the constant power factor load growth mode, calculate the static voltage stability limit of the AC channel between Bus2 and Bus3, as shown in Table 1. With the continuous increase of the remote load, the active and reactive power flow of the AC channel gradually increases, the bus voltage of the receiving end Bus3 gradually decreases, and the LPQ index continues to increase. The calculated static voltage stability limit is 3450MW, and the corresponding LPQ index at this time is 0.9782, very close to 1, indicat...

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Abstract

The invention provides an on-line voltage stability determination system of an alternating current and direct current mixing connection system. The on-line voltage stability determination system comprises a real-time data collection module, a power transmission line two-node model construction module, an on-line voltage stability evaluation indicator calculation module, and a system instability determination module. The real-time data collection module collects resistances R, reactances X, admittances B, active powers PB of receiving terminals, passive powers QB of receiving terminals and feeding terminal bus voltages UA in real time; the power transmission line two-node model construction module constructs two-node models of the power transmission lines according to the parameters, collected in real time, of the power transmission lines; the on-line voltage stability evaluation indicator calculation module calculates on-line voltage stability evaluation indicators of all power transmission lines based on the two-node models; and the system instability determination module determines whether the system reaches voltage instability boundary according to the on-line voltage stability evaluation indicators of all power transmission lines. According to the provided system, different voltage stability determination methods are used according to different fault properties, thereby improving the calculation speed.

Description

technical field [0001] The invention relates to the field of power system safety analysis, in particular to an on-line voltage stability judgment system of an AC / DC hybrid system. Background technique [0002] The successive occurrence of voltage collapse accidents in large power grids abroad has brought profound warnings to the electric power industry and has effectively promoted the in-depth development of the field of voltage stability. However, the theoretical system of voltage stability has not been perfected so far. Before the 1990s, the research on voltage stability mainly focused on static stability. At present, the research on dynamic voltage stability analysis method is being deepened continuously. Japan emphasizes the enhancement of the voltage control capability after the accident, while France focuses on the preventive measures in the state of emergency before the accident. Units such as Italian Power Grid, Swedish Power Grid, and Hydro-Quebec have also put in...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02J3/12
Inventor 唐晓骏马世英李再华张鑫程振龙林俊杰李晶罗红梅杨琦邱丽萍陈湘申旭辉张志强李晓珺吴丽华郑超宋云亭
Owner STATE GRID CORP OF CHINA