Sub-synchronous resonance monitoring method

A sub-synchronous resonance and sampling value technology, applied in the direction of frequency measurement devices, AC network circuits, electrical components, etc., can solve the problems of complex processing process and large calculation amount, and achieve small calculation amount, protection safety, and eliminate loop parameter conditions Effect

CN106226597AInactive Publication Date: 2016-12-14XUJI GRP +3
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2016-12-14
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a sub-synchronous resonance monitoring method. The method comprises the following steps: 1) acquiring line current in a series compensation system, and performing low-pass filtering on the line current; 2) sampling the line current after low-pass filtering, wherein the sampling indicates sampling one sampling value every M sampling values so as to convert sampling values with high sampling rate into sampling values with low sampling rate, and M is more than 1; 3) performing band-pass filtering on the sampled sampling values to generate sub-synchronous resonance current; and 4) calculating the effective value ISSR of the sub-synchronous resonance current, judging whether the ISSR is greater than the fixed value of the sub-synchronous resonance current, and if so, bypassing the series compensation system. The method eliminates circuit parameter conditions generated by sub-synchronous resonance, protects the safety of a generator shaft system, and improves the stability and the reliability of a system; and the measures of sectional calculation, sectional update, accumulation and the like can be taken by adopting sampling and a long-window effective value algorithm, so that the calculation quantity is small and relay protection can be realized.
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Description

technical field

[0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a subsynchronous resonance monitoring method. Background technique

[0002] The relay protection device requires that the faulty equipment can be reliably removed when the system fails to ensure the safe and stable operation of the system, but the damage caused by the incorrect action (including refusal and misoperation) of the protection device is also huge.

[0003] In recent years, a number of UHV lines have been put into operation. In order to increase the transmission capacity of the lines, the UHV lines have adopted a series capacitor scheme. In addition, for long lines with a voltage level above 500kV, in order to avoid the huge investment required for new lines, the method of adding series compensation capacitors to expand capacity is often used.

[0004] After the series compensation capacitor is added to the line, although the...

Examples

Embodiment Construction

[0030] The technical solution of the present invention will be described in further detail below in conjunction with the accompanying drawings.

[0031] The sub-synchronous resonance monitoring method is mainly used in the relay protection device of EHV and UHV series compensation system. As an independent functional module, it is integrated in the relay protection device of series compensation system. This function module is always on, and the process is as follows: figure 2 shown. The specific implementation process is:

[0032] 1) Collect the line current in the series compensation system in real time, and perform low-pass filter processing on the line current;

[0033] 2) Sampling the line current after the low-pass filtering process, the sampling refers to extracting 1 sampling value every M sampling values, thereby converting the high sampling rate sampling value into a low sampling rate sampling value, where M >1;

[0034] 3) Perform band-pass filtering on the sampl...