阅读说明：本技术 一种适应电气设备变频特性的微机保护方法和装置 (A kind of Microcomputer Protection method and apparatus adapting to electrical equipment frequency property ) 是由 刘小波 丁俊健 刘万斌 于 2019-08-09 设计创作，主要内容包括：本发明公开一种适应电气设备变频特性的微机保护方法和装置,方法包括：获取设备运行采样数据；根据采样数据计算设备当前实际频率；根据固定频率和设备实际频率,对采样数据进行校正,得到工频校正数据；按照预设的保护计算及采样数据选取规则,基于工频校正数据或原始采样数据进行多项保护计算,并根据保护计算的结果,控制保护动作执行机构执行保护动作。利用本发明可减小频率偏移带来的计算误差,使得设备在变频启动过程中,微机保护能够获得可靠的机组电气量变化数据,进而保障保护计算和逻辑判断的可靠性。(The present invention discloses a kind of Microcomputer Protection method and apparatus for adapting to electrical equipment frequency property, and method includes: to obtain equipment operation sampled data；The currently practical frequency of equipment is calculated according to sampled data；According to fixed frequency and equipment actual frequency, sampled data is corrected, obtains power frequency correction data；According to preset protection calculating and sampled data selection rule, multinomial protection calculating is carried out based on power frequency correction data or original sampling data, and according to protection calculating as a result, controlling protection act executing agency executes protection act.Frequency shift (FS) bring can be reduced using the present invention and calculate error, so that equipment, during variable frequency starting, Microcomputer Protection can obtain reliable unit electrical quantity delta data, and then ensure that protection calculates the reliability with logic judgment.)

1. a kind of Microcomputer Protection method for adapting to electrical equipment frequency property, characterized in that include:

It obtains equipment and runs sampled data；

The currently practical frequency of equipment is calculated according to sampled data；

According to equipment rated frequency and equipment actual frequency, sampled data is corrected, obtains power frequency correction data；

According to preset protection calculating and sampled data selection rule, carried out based on power frequency correction data or original sampling data more Item protection calculates, and according to protection calculating as a result, controlling protection act executing agency executes protection act.

2. according to the method described in claim 1, it is characterized in that, the equipment operating data be equipment during startup be System voltage and current data.

3. according to the method described in claim 1, it is characterized in that, further include distinguishing original sampling data and power frequency correction data It stores to different storage zone.

4. according to the method described in claim 1, it is characterized in that, sampled data be corrected include:

It determines correction reference data point, is denoted as X₀, with X₀Sampled data window for correction reference data point is [X₀, X₁......X_N-1]；

Assuming that the currently practical frequency of equipment is F₁, required power frequency correction data is M, then power frequency correction data X_j' are as follows:

In formula,Counting period Δ f=j*F between target correction sampled point and actual samples point₀-i*F₁, F₀ For system power voltagerating frequency, F₁For system power voltage actual frequency, INT () indicates to be rounded the parameter in bracket；p (F₁) it is predetermined correction data frequency compensation coefficient.

5. according to the method described in claim 4, it is characterized in that, the correction data frequency compensation coefficient are as follows:

p(F₁)=m₁*F₁+m₂

In formula, the proportionality coefficient m of frequency compensation coefficient₁With intercept m₂Determination method include:

Apply current or voltage, frequency 50Hz, amplitude A0 in AC sampling channel with relay-protection tester；

Maintain application current or voltage amplitude A0 constant, change frequency is F₁₁, protective device display amplitude is A1, then has frequency F₁₁ Under correction data frequency compensation coefficient are as follows:

Maintain application current or voltage amplitude A0 constant, changing frequency again is F₁₂, protective device display amplitude is A2, then has F₁₂ Under little Zheng data frequency penalty coefficient are as follows:

Based on known A0, A1 and A2, following equation group is solved:

Obtain parameter m₁With m₂Value.

6. according to the method described in claim 1, it is characterized in that, the preset protection calculates and sampled data selection rule packet It includes:

When the currently practical frequency of equipment is less than first frequency setting value, it is latched other protection meters in addition to startup over-current protection Calculate function；

When the currently practical frequency of equipment is greater than first frequency setting value and sets less than second frequency setting value, or greater than third frequency When definite value, protection calculating is carried out using power frequency correction data；

When the currently practical frequency of equipment, which is greater than or equal to second frequency setting value, is less than third frequency setting value, adopted using original Sample data carry out protection calculating；

The first frequency setting value, second frequency setting value, third frequency setting value are sequentially increased；

Including injected type stator ground protection module, triple-frequency harmonics protective module, rotor earth fault protection module, frequency anomaly protection The special protection of module and over-excitation protection module calculates and startup over-current protection calculates, only with original sampling data into Row；

Recording is protected to use original sampling data.

7. according to the method described in claim 6, it is characterized in that, the first/bis-/tri- frequency setting value be 10Hz/49.5Hz/ 50.5Hz。

8. a kind of microcomputer protecting device for adapting to electrical equipment frequency property, characterized in that include:

Equipment operating data obtains module, for obtaining equipment operation sampled data；

Equipment actual frequency computing module, for calculating the currently practical frequency of equipment according to sampled data；

Sampled data correction module, for being corrected to sampled data, obtaining work according to fixed frequency and equipment actual frequency Frequency correction data；

And protection calculates and control output module, for being based on according to preset protection calculating and sampled data selection rule Power frequency correction data or original sampling data carry out multinomial protection calculating, and according to protection calculating as a result, control protection act Executing agency executes protection act.

9. the microcomputer protecting device according to claim 8 for adapting to electrical equipment frequency property, characterized in that Microcomputer Protection Device further includes data memory module, and data memory module includes original sampling data area and correction data area；The equipment fortune Row data are deposited in original sampling data area, and the power frequency correction data deposits in correction data area.

Technical field

The present invention relates to the Microcomputer Protection technical fields of the electrical equipments such as gas turbine group, pump-storage generator, especially A kind of Microcomputer Protection method and apparatus adapting to electrical equipment frequency property.

Background technique

During startup, Current Voltage frequency is variation, and conventional electric power generation for gas turbine group and pump-storage generator Machine protection algorism is designed based on power frequency, when electrical quantity frequency shift (FS) power frequency, will be generated biggish calculating error, and be worked as offset When bigger, it is bigger to calculate error.

The generator protection algorithm for adapting to the variation of electrical quantity frequency at present mainly has:

(1) frequency tracking algorithm

Protective device adjusts hardware sample frequency according to the variation of system electrical amount frequency, so that phase between two sampled points Potential difference and electrical quantity frequency are essentially identical when being power frequency, so can be calculated using traditional protection algorism.This algorithm It can effectively improve computational accuracy when electrical quantity frequency shift (FS), but also bring along some problems, comprising:

A, the frequency protection and over-excitation protection calculated value calculated using sampled point is unable to the variation of response frequency；

B, protective device recording does not react the variation of frequency.

(2) integral algorithm

This algorithm is unrelated with the calculating of electrical quantity frequency, directlys adopt zero passage integral algorithm and calculates electrical quantity virtual value, separately Differential protection difference current and stalling current can be calculated outside, but cannot calculate the positive-sequence component and negative sequence component of electrical quantity.

(3) changing data window algorithm

This algorithm calculates frequency first, and the length of data window is then calculated according to frequency meter.As protective device sample frequency is 1200Hz, current electrical quantity frequency are 40Hz, then the length of data window is that sampling number is 1200/40=30 in a cycle It is a, electrical quantity virtual value is then calculated using full wave Fourier algorithm.But since electrical quantity frequency is there are drift condition, cause to change Data window cannot precisely be corresponded to electrical quantity actual cycle, that is, in a cycle, the points of data window are not necessarily whole Number, such as current electrical quantity frequency are 47Hz, then points are 1200/47=25.53, then cause to calculate error, electrical quantity frequency Rate offset is bigger, and it is bigger to calculate error.

Summary of the invention

It is an object of the present invention to provide a kind of Microcomputer Protection method and apparatus for adapting to electrical equipment frequency property, reduce Frequency shift (FS) bring calculates error, so that equipment, during variable frequency starting, Microcomputer Protection can obtain reliable unit electricity Tolerance delta data, and then ensure that protection calculates the reliability with logic judgment.

The technical scheme adopted by the invention is as follows: a kind of Microcomputer Protection method adapting to electrical equipment frequency property, comprising:

It obtains equipment and runs sampled data；

The currently practical frequency of equipment is calculated according to sampled data；

According to equipment rated frequency and equipment actual frequency, sampled data is corrected, obtains power frequency correction data；

Calculated according to preset protection and sampled data selection rule, based on power frequency correction data or original sampling data into The multinomial protection of row calculates, and according to protection calculating as a result, control protection act executing agency executes protection act.

Calculating the currently practical frequency of equipment according to sampled data can be used existing frequency measurement algorithm.The present invention is applying When, a data window is obtained respectively to the sampling of every wheel of equipment operating data, to the correction of sampled data also according to obtained Data window successively persistently carries out, so as to the variation of tracking equipment actual frequency.

Preferably, the equipment operation sampled data is to acquire according to default fixed frequency, and equipment is during startup System voltage and current data；

Sampled data is corrected according to preset data points, obtains the power frequency correction data of corresponding data points. Equipment can be, but not limited to, gas turbine or pump-storage generator etc..

It is pre- that the fixed sampling frequency setting of equipment operating data should make the sampled data window length an of cycle be greater than If data points, preset data points set according to needed for protection algorism.Since the present invention does not use changing data window algorithm, And the power frequency correction data that the data by obtaining to sampling are corrected to obtain specified data point is calculated for protection algorism, is come It avoids calculating deviation caused by electrical quantity frequency shift (FS), therefore sample frequency can not also do the limitation whether fixed, need to only obtain Greater than the sampled data window of preset data points.

Further, the invention also includes store original sampling data and power frequency correction data to different memory areas respectively Domain.Difference protection is calculated execution module and is corrected using the original sampling data or power frequency of data source pointer reading respective memory regions Data.

Preferably, sampled data is corrected and includes:

It determines correction reference data point, is denoted as X₀, with X₀Sampled data window for correction reference data point is [X₀, X₁......X_N-1]；

Assuming that the currently practical frequency of equipment is F₁, required power frequency correction data is M, then power frequency correction data X_j' are as follows:

In formula,Counting period Δ f=j*F between target correction sampled point and actual samples point₀-i* F₁, F₀For system power voltagerating frequency, F₁For system power voltage actual frequency, INT () is indicated to the parameter in bracket It is rounded；p(F₁) it is predetermined correction data frequency compensation coefficient.

Above-mentioned correction reference data point can be any point in a sampling period corresponding original sampling data, institute The number of the power frequency correction data M needed is determined according to algorithm needs in protection calculating, i.e., aforementioned preset data points, school The selection of positive benchmark data point should meet so that corresponding sampled data window length is greater than M.

Preferably, the correction data frequency compensation coefficient are as follows:

p(F₁)=m₁*F₁+m₂

In formula, the proportionality coefficient m of frequency compensation coefficient₁With intercept m₂Determination method include:

Apply current or voltage, frequency 50Hz, amplitude A0 in AC sampling channel with relay-protection tester；

Maintain application current or voltage amplitude A0 constant, change frequency is F₁₁, protective device display amplitude is A1, then has frequency Rate F₁₁Under correction data frequency compensation coefficient are as follows:

Maintain application current or voltage amplitude A0 constant, changing frequency again is F₁₂, protective device display amplitude is A2, then There is F₁₂Under little Zheng data frequency penalty coefficient are as follows:

Based on known A0, A1 and A2, following equation group is solved:

Obtain parameter m₁With m₂Value.

Preferably, preset protection of the present invention calculates and sampled data selection rule includes:

When the currently practical frequency of equipment is less than first frequency setting value, it is latched other guarantors in addition to startup over-current protection Protect computing function；

When the currently practical frequency of equipment be greater than first frequency setting value and be less than second frequency setting value, or be greater than third frequency When rate setting value, protection calculating is carried out using power frequency correction data；

When the currently practical frequency of equipment, which is greater than or equal to second frequency setting value, is less than third frequency setting value, using original Beginning sampled data carries out protection calculating；

The first frequency setting value, second frequency setting value, third frequency setting value are sequentially increased；

Including injected type stator ground protection module, triple-frequency harmonics protective module, rotor earth fault protection module, frequency anomaly The special protection of protective module and over-excitation protection module calculates and startup over-current protection calculates, only with crude sampling number According to progress；

Recording is protected to use original sampling data.

Preferably, the first/bis-/tri- frequency setting value is 10Hz/49.5Hz/50.5Hz.Specific value can be corresponding It slightly floats value two sides.

Invention additionally discloses a kind of microcomputer protecting devices for adapting to electrical equipment frequency property, comprising:

Equipment operating data obtains module, for obtaining equipment operation sampled data；

Equipment actual frequency computing module, for calculating the currently practical frequency of equipment according to sampled data；

Sampled data correction module, for being corrected, obtaining to sampled data according to fixed frequency and equipment actual frequency To power frequency correction data；

And protection calculates and control output module, is used for according to preset protection calculating and sampled data selection rule, Multinomial protection calculating is carried out based on power frequency correction data or original sampling data, and is protected according to what protection calculated as a result, controlling Action actuating mechanism executes protection act.

Preferably, microcomputer protecting device further includes data memory module, and data memory module includes original sampling data area With correction data area；The equipment operating data is deposited in original sampling data area, and the power frequency correction data deposits in school Correction data area.On this basis, modularized design, original sampling data area and correction data area can be used in all types of protection calculating Data pass through data source pointer respectively and pass to each protection computing module, then each protection computing module is further according to frequency Size and preset sampled data selection rule carry out calculate data source switching, then carry out protection calculate and logic sentence It is disconnected.

Beneficial effect

The present invention carries out algorithm correction to original sample point by calculating measurement frequency first, further according to the size of frequency, Each protective module can voluntarily select protection to calculate data source, energy according to the specific demand of electrical quantity frequency and protective module itself It effectively solves frequency shift (FS) bring and calculates error, the positive-sequence component and negative sequence component of electrical quantity are computed correctly, using the present invention Frequency protection and over-excitation protection calculated value energy response frequency variation, protective device electrical quantity recording can correctly reflect frequency Variation.

Detailed description of the invention

Fig. 1 show the method for the present invention schematic diagram；

Fig. 2 show a kind of specific embodiment flow diagram of the method for the present invention；

Generator terminal three-phase current recording schematic diagram when Fig. 3 is hydroenergy storage station pumped storage unit SFC starting；

Generator terminal three-phase voltage recording schematic diagram when Fig. 4 is certain hydroenergy storage station pumped storage unit SFC starting.

Specific embodiment

It is further described below in conjunction with the drawings and specific embodiments.