CN103543317B - For measuring the method for IEC standard voltage flickering - Google Patents

Abstract

The present invention relates to the method for measuring IEC standard voltage flickering, comprising: measuring system initialize, gather voltage peak, preprocessed data, processes data by inquiring arithmetic, by frequency compensation algorithm process data, calculate the value of voltage flickering in short-term, voltage flickering value when calculating long. The present invention reduces RAM storage space occupancy with the calculating process simplified, and ensures sampling continuity, so that it is guaranteed that measuring accuracy.

Description

For measuring the method for IEC standard voltage flickering

Technical field

The present invention relates to a kind of method for measuring IEC standard voltage flickering, the Power Quality Detection being applied in power system power supply-distribution system and analysis.

Background technology

According to the applicant understood, voltage flickering (VoltageFlicker) refers to that incandescent light causes the human eye vision of lamp illuminance instability to react because of voltage fluctuation. Why select incandescent light as with reference to standard, it is because in office, commercial, covil construction, incandescent light occupies sizable ratio, and square being directly proportional of the luminous power of incandescent light and electrical network voltage, maximum by voltage influence of fluctuations. In power system, voltage flickering is one of parameter important in quality of power supply evaluation criteria.

Owing to national government advocates Sustainable development, require to develop energetically and utilize renewable energy source, in the novel electric power system in future, the new forms of energy such as sun power, wind energy will be connected to the grid on a large scale, owing to these energy are limited to geographical conditions, weather, can only being connected to the grid by interval type, electrical network can be produced relatively large disturbances by the moment starting to be incorporated to and depart from electrical network at them like this, cause the prominent liter of electrical network voltage cycle time level, dash forward and fall, be unfavorable for ensureing that the quality of power supply is stablized. simultaneously, following novel power impact and wavy load can get more and more, such as steel-making arc stove, by the rolling mill of thyristorized supply, welding machine, electric locomotive etc., its power even tens0000 kilowatts up to several ten thousand kilowatts, owing to the power factor of this kind of interference load is generally compared with low and wattless power variable quantity is big, the voltage magnitude causing points of common connection (PCC) is operationally significantly changed by these loads fast, may make other electric installation under same electromagnetic environment can not normal operation time serious, to producing the impact brought in economy and benefit, inconvenience is brought to the life of people. this just needs the voltage flickering measurement method of high precision, can accurately measure voltage flickering, takes measures to provide early warning for power system.

Existing voltage flickering measurement method adopts Fast Fourier Transform (FFT) (FFT) to carry out computing (such as the Chinese invention patent application of application number 201110124225.4 publication No. CN102288807A) mostly, but the problem of this kind of method is: the calculating process more complicated of Fast Fourier Transform (FFT), a large amount of RAM storage spaces need to be taken during computing, the operation of master routine task can be affected, make whole measuring system easily therefore lose ripple in sampling process, cause measuring accuracy accurate not.

Summary of the invention

Technical problem to be solved by this invention is: for prior art Problems existing, a kind of method for measuring IEC standard voltage flickering is proposed, reduce RAM storage space occupancy with the calculating process simplified, ensure sampling continuity, so that it is guaranteed that measuring accuracy.

The technical scheme that the present invention solves its technical problem is as follows:

A kind of method for measuring IEC standard voltage flickering, it is characterized in that, it is applied to the measuring system being made up of controller and three-phase electrical energy computation chip, described controller and three-phase electrical energy computation chip communication connection, described three-phase electrical energy computation chip is in order to automatically to calculate and deposits voltage peak, and described voltage peak is voltage wave peak value or voltage valley value; Described method comprises the following steps:

The first step, start measure; Measuring system initialize, clear empty all voltage weighted data U_j, and make j=1, clear empty all flickering value P of voltage in short-term_st[n], and make n=1;

2nd step, controller gather voltage peak:

S1. initialize, clear empty all voltage data u_i, and make i=1;

S2. the voltage peak that three-phase electrical energy computation chip is deposited is read, by this voltage peak stored in voltage data u_i, start from zero timing simultaneously;

S3. judge whether i equals the first preset value N, then make i=i+1 if not and wait that timing goes to S2 to during the 2nd preset value T, if then going to the 3rd step;

3rd step, controller preprocessed data:

S4. calculating voltage data u_iMean valueThen modulated wave data u' is calculated_i,1��i��N;

S5. calculate and formed each time value zero [k], k=(i-1)+N �� (j-1) residing for zero point excessively in sine modulation ripple by modulated wave data;

S6. calculating voltage weighted data

S7. judge whether j equals the 3rd preset value M, then make j=j+1 if not and go to the 2nd step, if then going to the 4th step;

Pass between described first preset value N and the 3rd preset value M is:Described 2nd preset value T is the electric power wave semi-period; Described 3rd preset value M >=1000;

Inquiring arithmetic process data pressed by 4th step, controller:

S8. the vibration frequency f of modulated wave is calculated_��,F_wFor electric power wave radian frequency;

Voltage fluctuation table during the unit instantaneous flicker S=1 S9. provided according to IEC standard, searches f_WResiding frequency separation, makes f₁<f_W<f₂; Calculate visual sense degree COEFFICIENT K fx, Kfx=[(f_W-f₁)��d₂+(f₂-f_W)��d₁]/(f₂-f₁); Go to the 5th step;

5th step, controller are by frequency compensation algorithm process data:

S10. relative voltage changing value is calculated ${(\mathrm{\&Delta;}u/\stackrel{\&OverBar;}{u})}_j=2\sqrt{2}\&times;U_j\&times;Kfx,1\&le;j\&le;M;$

6th step, controller calculate the value of voltage flickering in short-term:

S11. instantaneous vermicularizing alloy is calculated $S_j={({\left(\mathrm{\&Delta;}u/\stackrel{\&OverBar;}{u}\right)}_j/0.25\%)}^2,1\&le;j\&le;M;$

S12. from M instantaneous vermicularizing alloy S_jIn count 99.9%, 99%, 97%, 90%, the 50% big value of probability, respectively as P_0.1��P₁��P₃��P₁₀��P₅₀, then calculate the value P of voltage flickering in short-term_st[n], $P_{st}\&lsqb;n\&rsqb;=\sqrt{0.0314P_{0.1}+0.0525P_1+0.0657P_3+0.28P_{10}+0.08P_{50}};$

S13. judge whether n equals the 4th preset value Z, then make n=n+1 if not and go to the 2nd step, if then going to the 7th step; Described 4th preset value Z and long time voltage flickering X observing time pass be: Z=X/10 minute;

Voltage flickering value P when 7th step, controller calculate long_lt,Measurement terminates.

Preferably, the first preset value N=60, the 2nd preset value T=10 millisecond, the 3rd preset value M=1000, the 4th preset value Z=12.

Applicant finally draws above-mentioned measuring method after deeply practical studies, it is possible to when not adopting Fast Fourier Transform (FFT) FFT computing, accurately draws the value P of voltage flickering in short-term_stWith voltage flickering value P time long_lt. The inventive method adopts mode in batches, often criticizes taking some voltage peaks as a set of samples, and the computing of each data processing step is simple and quick, RAM storage space occupancy is low, expends time in very short, it may be achieved sampling limit, limit process data, and both are independent of each other, so that it is guaranteed that measuring accuracy.

Accompanying drawing explanation

Fig. 1 is the main process schematic diagram of the embodiment of the present invention.

Embodiment

With reference to the accompanying drawings and the present invention is described in further detail in conjunction with the embodiments. But the invention is not restricted to given example.

Embodiment

The present embodiment is for measuring the method for IEC standard voltage flickering, it is applied to the measuring system being made up of controller and three-phase electrical energy computation chip, controller and three-phase electrical energy computation chip communication connection, three-phase electrical energy computation chip is in order to automatically to calculate and deposits voltage peak, and voltage peak is voltage wave peak value or voltage valley value. Three-phase electrical energy computation chip can outsourcing, such as the ATT7022E of Ju Quan Optoelectronics Technology company; Controller can adopt MCU; Can spi bus communication connection between controller and three-phase electrical energy computation chip.

As shown in Figure 1, the present embodiment method comprises the following steps:

The first step, start measure; Measuring system initialize, clear empty all voltage weighted data U_j, and make j=1, clear empty all flickering value P of voltage in short-term_st[n], and make n=1;

2nd step, controller gather voltage peak:

S1. initialize, clear empty all voltage data u_i, and make i=1;

S2. the voltage peak that three-phase electrical energy computation chip is deposited is read, by this voltage peak stored in voltage data u_i, start from zero timing simultaneously;

S3. judge whether i equals the first preset value N, then make i=i+1 if not and wait that timing goes to S2 to during the 2nd preset value T, if then going to the 3rd step;

3rd step, controller preprocessed data:

S4. calculating voltage data u_iMean valueThen modulated wave data u' is calculated_i,1��i��N; In this step, willAs this group voltage data u_iDirect current component, then reject direct current component obtain modulated wave data u'_i��

S5. calculate and formed each time value zero [k], k=(i-1)+N �� (j-1) residing for zero point excessively in sine modulation ripple by modulated wave data;

S6. calculating voltage weighted data

S7. judge whether j equals the 3rd preset value M, then make j=j+1 if not and go to the 2nd step, if then going to the 4th step;

Pass between described first preset value N and the 3rd preset value M is:Described 2nd preset value T is the electric power wave semi-period; Described 3rd preset value M >=1000;

Inquiring arithmetic process data pressed by 4th step, controller:

S8. the vibration frequency f of modulated wave is calculated_W,F_wFor electric power wave radian frequency;

Voltage fluctuation table during the unit instantaneous flicker S=1 S9. provided according to IEC standard, searches f_WResiding frequency separation, makes f₁<f_W<f₂; Calculate visual sense degree COEFFICIENT K fx, Kfx=[(f_W-f₁)��d₂+(f₂-f_W)��d₁]/(f₂-f₁); Go to the 5th step;

Namely inquiring arithmetic in this step make use of the quick advantage tabled look-up, again by formula correction visual sense degree coefficient to improve the precision of flicker measurement.

5th step, controller are by frequency compensation algorithm process data:

S10. relative voltage changing value is calculated ${(\mathrm{\&Delta;}u/\stackrel{\&OverBar;}{u})}_j=2\sqrt{2}\&times;U_j\&times;Kfx,1\&le;j\&le;M;$ In this step, according to the single peak weighting filter effect centered by 8.8Hz, study out and change by the relative voltage of 8.8Hz frequency response characteristic.

6th step, controller calculate the value of voltage flickering in short-term:

S11. instantaneous vermicularizing alloy is calculated $S_j={({\left(\mathrm{\&Delta;}u/\stackrel{\&OverBar;}{u}\right)}_j/0.25\%)}^2,1\&le;j\&le;M;$

S12. from M instantaneous vermicularizing alloy S_jIn count 99.9%, 99%, 97%, 90%, the 50% big value of probability, respectively as P_0.1��P₁��P₃��P₁₀��P₅₀, then calculate the value P of voltage flickering in short-term_st[n], $P_{st}\&lsqb;n\&rsqb;=\sqrt{0.0314P_{0.1}+0.0525P_1+0.0657P_3+0.28P_{10}+0.08P_{50}};$

S13. judge whether n equals the 4th preset value Z, then make n=n+1 if not and go to the 2nd step, if then going to the 7th step; Described 4th preset value Z and long time voltage flickering X observing time pass be: Z=X/10 minute;

Voltage flickering value P when 7th step, controller calculate long_lt,Measurement terminates.

In the present embodiment, the first preset value N=60, the 2nd preset value T=10 millisecond, the 3rd preset value M=1000, the 4th preset value Z=12.

The present embodiment method is applied to the flicker measurement of south electric network distribution transforming measuring terminal in internal applications is tested, and in test process, measuring accuracy can control in 5%, meets the requirement of IEC standard, and effect is remarkable.

The present embodiment method efficiency height, precision height, can from basic solve Fast Fourier Transform (FFT) FFT computing complicated and affect by it cause lose ripple problem.

The present embodiment method utilizes the voltage peak of three-phase electrical energy computation chip continuous sampling half cycles, various processes (especially visual sense degree coefficient calculation step) computing is simple, arithmetic speed can be significantly improved, it is to increase measuring accuracy, reduce the demand to arithmetic hardware.

In addition to the implementation, the present invention can also have other enforcement modes. All employings are equal to replacement or the technical scheme of equivalent transformation formation, all drop on the protection domain of requirement of the present invention.

Claims (2)

1. one kind for measuring the method for IEC standard voltage flickering, it is characterized in that, it is applied to the measuring system being made up of controller and three-phase electrical energy computation chip, described controller and three-phase electrical energy computation chip communication connection, described three-phase electrical energy computation chip is in order to automatically to calculate and deposits voltage peak, and described voltage peak is voltage wave peak value or voltage valley value; Described method comprises the following steps:

The first step, start measure; Measuring system initialize, clear empty all voltage weighted data U_j, and make j=1, clear empty all flickering value P of voltage in short-term_st[n], and make n=1;

2nd step, controller gather voltage peak:

S1. initialize, clear empty all voltage data u_i, and make i=1;

S2. the voltage peak that three-phase electrical energy computation chip is deposited is read, by this voltage peak stored in voltage data u_i, start from zero timing simultaneously;

S3. judge whether i equals the first preset value N, then make i=i+1 if not and wait that timing goes to S2 to during the 2nd preset value T, if then going to the 3rd step;

3rd step, controller preprocessed data:

S4. calculating voltage data u_iMean valueThen modulated wave data u' is calculated_i,1��i��N;

S5. calculate and formed each time value zero [k], k=(i-1)+N �� (j-1) residing for zero point excessively in sine modulation ripple by modulated wave data;

S6. calculating voltage weighted data $U_j=\frac{1}{\stackrel{\&OverBar;}{u}}\&times;\sqrt{\frac{\underset{i=1}{\overset{N}{\&Sigma;}}{\left(\right|u_i|-\stackrel{\&OverBar;}{u})}^2}{N}};$

S7. judge whether j equals the 3rd preset value M, then make j=j+1 if not and go to the 2nd step, if then going to the 4th step;

Pass between described first preset value N and the 3rd preset value M is:Described 2nd preset value T is the electric power wave semi-period; Described 3rd preset value M >=1000;

Inquiring arithmetic process data pressed by 4th step, controller:

S8. the vibration frequency f of modulated wave is calculated_��,F_wFor electric power wave radian frequency;

Voltage fluctuation table during the unit instantaneous flicker S=1 S9. provided according to IEC standard, searches f_��Residing frequency separation, makes f₁<f_��<f₂; Calculate visual sense degree COEFFICIENT K fx,

Kfx=[(f_��-f₁)��d₂+(f₂-f_��)��d₁]/(f₂-f₁); Go to the 5th step;

5th step, controller are by frequency compensation algorithm process data:

S10. relative voltage changing value is calculated1��j��M;

6th step, controller calculate the value of voltage flickering in short-term:

S11. instantaneous vermicularizing alloy is calculated1��j��M;

S12. from M instantaneous vermicularizing alloy S_jIn count 99.9%, 99%, 97%, 90%, the 50% big value of probability, respectively as P_0.1��P₁��P₃��P₁₀��P₅₀, then calculate the value P of voltage flickering in short-term_st[n], $P_{st}\&lsqb;n\&rsqb;=\sqrt{0.0314P_{0.1}+0.0525P_1+0.0657P_3+0.28P_{10}+0.08P_{50}};$

S13. judge whether n equals the 4th preset value Z, then make n=n+1 if not and go to the 2nd step, if then going to the 7th step; Described 4th preset value Z and long time voltage flickering X observing time pass be: Z=X/10 minute;

Voltage flickering value P when 7th step, controller calculate long_lt,Measurement terminates.

2. according to claim 1 for measuring the method for IEC standard voltage flickering, it is characterized in that, the first preset value N=60, the 2nd preset value T=10 millisecond, the 3rd preset value M=1000, the 4th preset value Z=12.