CN101183606B - Electronic current transformer - Google Patents
Electronic current transformer Download PDFInfo
- Publication number
- CN101183606B CN101183606B CN2007100535622A CN200710053562A CN101183606B CN 101183606 B CN101183606 B CN 101183606B CN 2007100535622 A CN2007100535622 A CN 2007100535622A CN 200710053562 A CN200710053562 A CN 200710053562A CN 101183606 B CN101183606 B CN 101183606B
- Authority
- CN
- China
- Prior art keywords
- signal
- circuit
- current
- unit
- cycle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000006243 chemical reaction Methods 0.000 claims abstract description 55
- 239000013307 optical fiber Substances 0.000 claims abstract description 20
- 238000012545 processing Methods 0.000 claims abstract description 19
- 230000001052 transient effect Effects 0.000 claims abstract description 16
- 238000005070 sampling Methods 0.000 claims abstract description 15
- 238000000034 method Methods 0.000 claims description 17
- 230000008569 process Effects 0.000 claims description 9
- 239000000835 fiber Substances 0.000 claims description 5
- 230000008859 change Effects 0.000 claims description 4
- 238000012937 correction Methods 0.000 claims description 4
- 238000004364 calculation method Methods 0.000 claims description 2
- 230000000541 pulsatile effect Effects 0.000 claims description 2
- 238000010791 quenching Methods 0.000 claims description 2
- 230000000171 quenching effect Effects 0.000 claims description 2
- 230000003442 weekly effect Effects 0.000 claims description 2
- 238000005259 measurement Methods 0.000 abstract description 10
- 230000001360 synchronised effect Effects 0.000 abstract description 3
- 230000008901 benefit Effects 0.000 abstract description 2
- 230000007774 longterm Effects 0.000 abstract description 2
- 230000010354 integration Effects 0.000 description 9
- 230000005540 biological transmission Effects 0.000 description 6
- 238000013461 design Methods 0.000 description 5
- 230000003321 amplification Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 208000032368 Device malfunction Diseases 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000002045 lasting effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
Images
Landscapes
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
The invention relates to an electronic current transformer, belonging to the current transformer in the power system, which is suitable for current measurements of various high voltage grades of power system and solves the current problems of complex structure, difficult to accurately measure the transient fault current, poor long-term stability of the electronic current transformer. The high side-sensing unit is connected with a low voltage side signal processing unit through a signal optical fiber, the sensing unit comprises a rogowski coil, a sampling resistance, a low-pass filter circuit, an amplifying circuit, a pressure-frequency switching circuit, and an electro-optical conversion circuit; the signal processing unit comprises a photoelectric conversion circuit, a pulse counter and a microprocessor. The invention has the advantages of functions of analog-digital conversion and ideal integrator, no need of analog circuit or digital integral circuit in the sensing unit, no need of sampling synchronous signal, greatly simplified the structure of the transformer and hardware circuit, and improved reliability of the current transformer.
Description
Technical field
The invention belongs to the current transformer of electric power system, relate in particular to the electronic current mutual inductor of a kind of employing Luo Shi (Rogowski) coil, voltage to frequency conversion circuit and pulse counter, be applicable to the current measurement of each electric pressure electric power system of high pressure.
Background technology
Power industry is at present mainly adopted and is contained electromagnetic current transducer measurement primary current unshakable in one's determination.Excessive tested electric current and the aperiodic component in the fault current all make the unshakable in one's determination saturated of electromagnetic current transducer easily, cause the distortion of instrument transformer output waveform, and then probably cause protective relaying device malfunction or tripping.And the electromagnetic transformer that is used for high pressure adopts oil-insulation mostly, has potential safety hazards such as inflammable and explosive.Simultaneously, along with the raising of voltage class of electric power system, the instrument transformer insulating Design that becomes increasingly complex also makes the cost of instrument transformer sharply rise.In addition, the simulation of electromagnetic transformer output is difficult to and digitized secondary device direct interface, can not adapt to the digital development trend of transformer station.
Electronic current mutual inductor adopt devices such as optics or Luo-coil as sensing element to obtain tested current signal, and adopt optical fiber to transmit signal, thereby fundamentally overcome electromagnetic current transducer unshakable in one's determination easily saturated, insulating Design is difficult, shortcoming that can not Direct Digital output.Electronic current mutual inductor generally is made of the signal optical fibre three parts that are positioned on high-tension side sensing unit, are positioned at the signal processing unit of low-pressure side and connect both.At present existing multi-form employing Luo-coil puts into operation as the electronic current mutual inductor of sensing unit or trys out.
The output signal of Luo-coil is the differential of tested electric current, in order to obtain tested current signal, need carry out the integration reduction to the Luo-coil output signal.At present, adopt the electronic current mutual inductor great majority of Luo-coil to utilize analog integrator circuit to realize integrating function, though analog integrator circuit has good integral action to the steady-state sine electric current, but the transient process that but can not accurately reflect fault current, and analog integrator circuit self just is subjected to the influence of ambient temperature easily, so will design an energy long-term stable operation and can reflect well that the analog integrator circuit of fault current transient process is the comparison difficulty." based on the current mutual inductor with hollow coil of digital integration " of the patent No. 200520070558.3 proposed to utilize the fpga chip with digital integration function to realize integration, can obtain long-time stability preferably, but be subjected to the restriction of integration frequency bandwidth, still can not accurately reflect the transient process of fault current.
The people is arranged at present, and (Voltage-to-Frequency Converter, VFC) circuit application is in electronic current mutual inductor, but present VFC circuit all can not be realized good integrating function with voltage to frequency conversion." a kind of electronic type high-tension current inductor " of the patent No. 00265522.5 adopts Luo-coil to obtain the differentiated waveform of tested current signal, with integrating amplification circuit the Luo-coil output signal is carried out integration, output signal with integrating amplification circuit is pulse by the VFC circuit conversion then, and delivers to low-pressure side by optical fiber; Because this patent has been used integrating amplification circuit, so its VFC circuit there is no integrating function and analog-digital conversion function, this patent only just utilizes the insulation between VFC circuit and optical fiber realization high-pressure side and the low-pressure side to isolate.
Authors such as Li Fuying have delivered article " based on the current measuring method of Rogowski coil and voltage to frequency conversion " in " Tsing-Hua University's journal (natural science edition) " 2000 the 40th the 3rd phase the 28th of volume to the 31st page, authors such as Nie Yixiong have delivered article " research of electronic mutual inductor analog-to-digital conversion method " in " relay " the 2005th the 33rd the 6th phase the 46th of volume to the 50th page, authors such as Nie Yixiong have delivered article " application of voltage-frequency converter in electronic mutual inductor " in " University Of Shantou's journal (natural science edition) " the 2006th the 21st the 2nd phase the 59th of volume to the 64th page, VFC circuit and the application of pulse counter in electronic current mutual inductor studied in these three pieces of articles, they all are by the VFC circuit Luo-coil output signal to be converted to pulse, and paired pulses is counted then.These three pieces of articles are all pointed out, must choose the step-by-step counting cycle of length-specific.This method of counting comes down to a kind of counting of short time window, count cycle must be much smaller than a primitive period, the frequency response characteristic that does not have the full range band, its result is said as the conclusion of these three pieces of articles, this method of counting does not have the distortion of amplitude and phase place for odd-order harmonic components, but will filter even harmonics fully.Yet the electric current of practical power systems includes the inferior and even harmonics component of abundant odd number, so the output waveform that this method of counting obtains will distort.
Electronic current mutual inductor generally adopts the successive approximation analog-to-digital conversion to realize the conversion of analog signal to digital signal on high-tension side sensing unit at present, and this obtains the sample-synchronous signal with regard to requiring sensing unit from the signal processing unit of low-pressure side.Because the insulation that need satisfy between high-pressure side and the low-pressure side is isolated and strict sample-synchronous required precision, " based on the synchronous laser energy supply high pressure photoelectric current inductor of GPS " of " the multiphase digital photoelectric type current transformer of synchronized sampling " of the patent No. 03125398.9 and the patent No. 200620031571.2 proposed the device of current two kinds of main transmission sample-synchronous signals respectively, these install all more complicated, have reduced the reliability of electronic current mutual inductor.
Summary of the invention
The invention provides a kind of electronic current mutual inductor, this instrument transformer utilizes Luo-coil to respond to tested electric current, and the cooperation by VFC circuit, pulse counter and microprocessor, the current differential signal of Luo-coil output is carried out the integration reduction obtain tested current signal, solve current electronic current mutual inductor complex structure, be difficult to accurately measure the problem of transient state fault current, long-time stability difference, to improve certainty of measurement.
A kind of electronic current mutual inductor of the present invention comprises the signal optical fibre that is positioned on high-tension side sensing unit, is positioned at the signal processing unit of low-pressure side and connects both; It is characterized in that:
Described high-pressure side sensing unit comprises Luo-coil, sample resistance, low-pass filter circuit, amplifying circuit, voltage to frequency conversion circuit, the electro-optical conversion circuit that is linked in sequence with the signal of telecommunication; The differential signal of the transient change electric current that obtains by Luo-coil and sample resistance, carry out signal condition through low-pass filter circuit, amplifying circuit, become the electric impulse signal of reflection transient change current differential information again by the voltage to frequency conversion circuit conversion, electric impulse signal converts light pulse signal to through electro-optical conversion circuit, sends into signal optical fibre;
Described signal optical fibre sends light pulse signal to signal processing unit;
Described signal processing unit is made up of photoelectric switching circuit, pulse counter and microprocessor, photoelectric switching circuit converts the light pulse signal of signal optical fibre to electric impulse signal, deliver to pulse counter, behind microprocesser initialization and the starting impulse counter, pulse counter is counted electric impulse signal, microprocessor carries out data processing to count value, thereby obtains the digital sample value sequence of tested electric current;
Described microprocesser initialization process is: calculate each cycle sampling number predetermined value according to required sample rate, put current cycle initial value for integral variable i
S0Be zero, putting microprocessor output waveform side-play amount b is zero, and the pulse counter initial value is predisposed to zero;
Initialization procedure finishes, the starting impulse counter;
Described microprocessor carries out data processing to count value and comprises the steps:
(1) in each sampling instant, read the count value N (k) of pulsatile once counter, count value is carried out data processing by following formula:
i
s(k)＝R×(N(k)-f
0×(t
k-t
0))+i
s0
In the formula, k tested current sampling data i of microprocessor output
s(k), unit is A;
Output sampled value sequence number k;
The scale conversion coefficients R is used for pulse number is converted to size of current, and unit is A/;
K count value N of pulse counter (k), unit are individual;
With carry the corresponding pulse frequency f of bias voltage in the voltage to frequency conversion chip
0, unit is Hz;
With k sampled value time corresponding value t
k, unit is second;
The start time t of step-by-step counting
0, unit is second;
This cycle initial value for integral i
S0, unit is A;
(2) when this cycle sampling number reaches weekly ripple sampling number predetermined value, preserve the current output valve i of microprocessor
s(k) as the initial value for integral i of next cycle
S0, the quenching pulse counter; Judging that whether this cycle is first cycle after program begins, is that then order is carried out, otherwise changes step (1);
(3) calculate the mean value of this cycle microprocessor output valve,, and press the initial value for integral i of the next cycle of following formula correction the side-play amount b of result of calculation as the microprocessor output valve
S0:
i
s0＝i
s0-b
Correction finishes, and changes step (1).
Described electronic current mutual inductor is characterized in that: described high-pressure side sensing unit comprises the high-pressure side power module, and the high-pressure side power module provides power supply for low-pass filter circuit, amplifying circuit, voltage to frequency conversion circuit and electro-optical conversion circuit; The laser energy supply module connects the high-pressure side power module by Power Fiber, for it provides light energy.
The present invention realizes integrating function by the cooperation of voltage to frequency conversion circuit, pulse counter and microprocessor.Note amplifying circuit output signal is u
0(t), voltage to frequency conversion circuit output pulse string has frequency f (t), then has:
f(t)＝M×u
0(t) (1)
M is the voltage to frequency conversion coefficient of VFC circuit in the formula (1), and unit is Hz/V.
Pulse train is sent to the signal processing unit of low-pressure end by electro-optical conversion circuit and signal optical fibre, and the pulse train of the pulse train of photoelectric switching circuit output and the output of voltage to frequency conversion circuit will have same frequency f.Determine the start time t of good counting
0After, the counting that the pulse train that photoelectric switching circuit is exported continues.The section of clocking Δ t
k=t
K+1-t
k, as Δ t
kU in period
0When (t) being steady voltage, should period f (t) be steady state value then, from start time t
0Count value N until moment t can be expressed as follows:
Work as u
0When (t) changing, f (t) also changes, and according to the differential principle, formula (2) can be transformed to following formula:
According to formula (1) and integral principle, can further obtain following formula from formula (3):
Therefore, from t
0To t paired pulses string continue the result of counting and in this time period to u
0(t) definite integral relation in direct ratio.So microprocessor reads count value one time every a sampling time interval, then according to formula
i
s(k)＝R×(N(k)-f
0×(t
k-t
0))+i
s0 (5)
Handling count value can obtain u
0(t) signal waveform of integration.
Therefore, said method can be realized u
0(t) integration, and u
0(t) be the differential of the tested current signal on the power transmission line, so the present invention finally can obtain the signal waveform of tested electric current.
Simultaneously, from above-mentioned analysis as seen, the present invention has just realized u in the process that paired pulses is counted
0(t) analog-to-digital conversion, and the present invention need not to obtain the sample-synchronous signal with complicated method from low-pressure side as the successive approximation analog-to-digital conversion.Need export the moment t of sampled value at each, the count value that the present invention reads all is from t
0Beginning until t to u
0(t) result of lasting counting so the present invention can obtain the sample rate up to 10kHz in concrete enforcement, and by the counting that the pulse to the output of VFC circuit continues, can obtain higher resolution.
For working power being provided for the high-side signal treatment circuit, the present invention takes the laser energy supply method, promptly the light energy that the laser energy supply circuit provides is sent to the high-pressure side, light energy is converted to electric flux, supply with the high-side signal treatment circuit by the high-pressure side power module by large-power optical fiber.
Compare with prior art, the present invention has following advantage:
1. the stability of operation of current transformers and output result's precision have been improved.The present invention does not adopt analog integrator circuit, by the realize ideal function of integrator of the cooperation of voltage to frequency conversion circuit, pulse counter and microprocessor, the transient process that can correctly reflect fault current, have high-resolution and high sampling rate simultaneously, fundamentally overcome the shortcoming that analog integrator circuit is influenced by ambient temperature easily, can not accurately measure the transient state fault current.
2. the ability that has anti-High-frequency Interference improves the reliability that current transformer is exported the result greatly.If the sign bit of common successive approximation analog-to-digital conversion numeral output or the bigger data bit of weight are because of the impulse disturbances displacement, and just might making this time, gross mistake appears in the analog-to-digital conversion result.And voltage to frequency conversion of the present invention only is many several or few several pulses in thousands of the pulses if be subjected to impulse disturbances, and is very little to instrument transformer output result's influence.
3. be positioned on high-tension side sensing unit and need not the sample-synchronous signal, greatly simplified circuit design, improved the reliability of current transformer device.
Thereby the present invention has analog-digital conversion function and ideal integrator function by the cooperating of VFC circuit, pulse counter and microprocessor, can verily reflect the contained harmonic component of signal that enters the VFC chip, is a kind of desirable full range band integrator.Sensing unit need not analog integrator circuit or digital integrating circuit, and need not the sample-synchronous signal, thereby has simplified the design of instrument transformer greatly, has improved the reliability of device.
Description of drawings
Fig. 1 is a circuit block diagram of the present invention, mark among the figure: power transmission line 1, Luo-coil 2, sample resistance 3, low-pass filter circuit 4, amplifying circuit 5, voltage to frequency conversion circuit 6, electro-optical conversion circuit 7, signal optical fibre 8, photoelectric switching circuit 9, pulse counter 10, microprocessor 11, laser energy supply module 12, Power Fiber 13, high-pressure side power module 14.
Fig. 2 is the microprocessor processes program flow diagram;
Fig. 3 (a) is the measurement result of divertor to the steady-state sine electric current;
Fig. 3 (b) is the signal u that exports and be about to enter the VFC circuit when measuring the steady-state sine electric current from amplifying circuit of the present invention
0
Fig. 3 (c) is the measurement result of the present invention to the steady-state sine electric current;
Fig. 4 (a) is the measurement result of divertor to the transient state fault current;
Fig. 4 (b) is the signal u that exports and be about to enter the VFC circuit when measuring the transient state fault current from amplifying circuit of the present invention
0
Fig. 4 (c) is the measurement result of the present invention to the transient state fault current.
Embodiment
As shown in Figure 1, the present invention includes the signal optical fibre 8 that is positioned on high-tension side sensing unit, is positioned at the signal processing unit of low-pressure side and connects both; The high-pressure side sensing unit comprises Luo-coil 2, sample resistance 3, low-pass filter circuit 4, the amplifying circuit 5 that is linked in sequence with the signal of telecommunication, voltage to frequency conversion circuit 6, electro-optical conversion circuit 7; Signal processing unit is made up of photoelectric switching circuit 9, pulse counter 10 and microprocessor 11.
High-pressure side power module 14 provides power supply for low-pass filter circuit 4, amplifying circuit 5, voltage to frequency conversion circuit 6 and electro-optical conversion circuit 7; Laser energy supply module 12 connects high-pressure side power module 14 by Power Fiber 13, for it provides light energy.
Choose precision operational-amplifier OP177 and constitute low-pass filter circuit 4, amplifying circuit 5; Choose voltage to frequency conversion chip AD7742 and constitute voltage to frequency conversion circuit 6, choose optical launcher HFBR-1414T and constitute electro-optical conversion circuit 7, signal optical fibre 8 adopts 62.5 μ m/125 μ m multi-mode communication optical fiber, select for use optical receiver HFBR-2416T to constitute photoelectric switching circuit 9, pulse counter 10 adopts 8254-2.
The range size of voltage to frequency conversion chip AD7742 input signal is-2.5V is to+2.5V, so at first the signal magnitude on the sample resistance 3 to be adjusted to-2.5V within the+2.5V, just can send into AD7742.When input signal ceiling voltage+2.5V, AD7742 output pulse has highest frequency 2.77MHz.Constitute fiber optic transmission system by electro-optical conversion circuit 8, signal optical fibre 9 and photoelectric switching circuit 10, this transmission system transmission data bit-rate is 32Mbps, can reliably pulse be sent to the input of pulse counter 11.
The voltage to frequency conversion output pulse frequency corresponding with bias voltage in the AD7742 chip is 1.536MHz, when microprocessor 12 reads count value, count value need be deducted the pulse number that 1.536MHz produced in the timing time.
When the counting beginning, be difficult to find the zero crossing of tested electric current and from then on constantly begin counting.When power system mesomeric state moved, the mean value of electric current will be zero in the complete cycle ripple that begins at any time, and microprocessor output of the present invention also should be like this.But begin counting constantly from the non-zero passage of tested electric current, microprocessor output waveform will rise overally or descend a certain size, i.e. the mean value non-zero of waveform in the cycle.The mean value of first complete cycle ripple output waveform of microprocessor output can be calculated to this earlier,, just correct signal can be obtained as long as the later output of microprocessor deducts this mean value.
The microprocessor processes program flow diagram as shown in Figure 2.
After apparatus of the present invention are made and are finished, for simplicity, can adopt sinusoidal steady-state sine electric current to determine the scale conversion coefficients R in the debug phase, concrete grammar is as follows: measuring effective value with apparatus of the present invention is the steady-state sine electric current of A, preset R=1, microprocessor of the present invention will be exported a steady-state sine current i this moment
s, calculate i
sEffective value be B, then redefine the scale conversion coefficients R according to following formula:
For proving that the present invention measures the correctness of electric current, adopt divertor and the present invention to measure same electric current simultaneously to compare, because divertor is a resistance element, so the tested current signal waveform that divertor obtains will be true and reliable.The abscissa of Fig. 3 (a), Fig. 3 (b), Fig. 3 (c) all is second (s).Remember that tested electric current is i
p, Fig. 3 (a) is the steady-state sine current i that divertor records
p, ordinate unit is an ampere (A); Fig. 3 (b) is the signal u that exports and be about to enter the VFC circuit from amplifying circuit of the present invention
0, u
0Be proportional to the differential of tested electric current, ordinate unit is a volt (V); Fig. 3 (c) is microprocessor output of the present invention i as a result
s, ordinate unit is an ampere (A).Contrast as seen from Fig. 3 (a) and Fig. 3 (c), the present invention has good measurement performance to the steady-state sine electric current.
The abscissa of Fig. 4 (a), Fig. 4 (b), Fig. 4 (c) all is second (s).Fig. 4 (a) is the transient state fault current i that divertor records
p, ordinate unit is an ampere (A); Fig. 4 (b) is the signal u that exports and be about to enter the VFC circuit from amplifying circuit of the present invention
0, u
0Be proportional to the differential of tested electric current, ordinate unit is a volt (V); Fig. 4 (c) is microprocessor output of the present invention i as a result
s, ordinate unit is an ampere (A).Contrast as seen from Fig. 4 (a) and Fig. 4 (c), the present invention has good measurement performance to the transient state fault current.
Claims (2)
1. an electronic current mutual inductor comprises the signal optical fibre that is positioned on high-tension side sensing unit, is positioned at the signal processing unit of low-pressure side and connects both; It is characterized in that:
Described high-pressure side sensing unit comprises Luo-coil, sample resistance, low-pass filter circuit, amplifying circuit, voltage to frequency conversion circuit, the electro-optical conversion circuit that is linked in sequence with the signal of telecommunication; The differential signal of the transient change electric current that obtains by Luo-coil and sample resistance, carry out signal condition through low-pass filter circuit, amplifying circuit, become the electric impulse signal of reflection transient change current differential information again by the voltage to frequency conversion circuit conversion, electric impulse signal converts light pulse signal to through electro-optical conversion circuit, sends into signal optical fibre;
Described signal optical fibre sends light pulse signal to signal processing unit;
Described signal processing unit is made up of photoelectric switching circuit, pulse counter and microprocessor, photoelectric switching circuit converts the light pulse signal of signal optical fibre to electric impulse signal, deliver to pulse counter, behind microprocesser initialization and the starting impulse counter, pulse counter is counted electric impulse signal, microprocessor carries out data processing to count value, thereby obtains the digital sample value sequence of tested electric current;
Described microprocesser initialization process is: calculate each cycle sampling number predetermined value according to required sample rate, put this cycle initial value for integral variable i
S0Be zero, putting microprocessor output waveform side-play amount b is zero, and the pulse counter initial value is predisposed to zero;
Initialization procedure finishes, the starting impulse counter;
Described microprocessor carries out data processing to count value and comprises the steps:
(1) in each sampling instant, read the count value N (k) of pulsatile once counter, count value is carried out data processing by following formula:
i
s(k)＝R×(N(k)-f
0×(t
k-t
0))+i
s0
In the formula, k tested current sampling data i of microprocessor output
s(k), unit is A;
Output sampled value sequence number k;
The scale conversion coefficients R is used for pulse number is converted to size of current, and unit is A/;
K count value N of pulse counter (k), unit are individual;
With carry the corresponding pulse frequency f of bias voltage in the voltage to frequency conversion chip
0, unit is Hz;
With k sampled value time corresponding value t
k, unit is second;
The start time t of step-by-step counting
0, unit is second;
This cycle initial value for integral i
S0, unit is A;
(2) when this cycle sampling number reaches weekly ripple sampling number predetermined value, preserve current time microprocessor output valve i
s(k) as the initial value for integral i of next cycle
S0, the quenching pulse counter; Judging that whether this cycle is first cycle after program begins, is that then order is carried out, otherwise changes step (1);
(3) calculate the mean value of this cycle microprocessor output valve, result of calculation is designated as the side-play amount b of microprocessor output valve, and presses the initial value for integral i of the next cycle of following formula correction
S0:
i
s0＝i
s0-b
Correction finishes, and changes step (1).
2. electronic current mutual inductor as claimed in claim 1, it is characterized in that: described high-pressure side sensing unit comprises the high-pressure side power module, and the high-pressure side power module provides power supply for low-pass filter circuit, amplifying circuit, voltage to frequency conversion circuit and electro-optical conversion circuit; The laser energy supply module connects the high-pressure side power module by Power Fiber, for it provides light energy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100535622A CN101183606B (en) | 2007-10-15 | 2007-10-15 | Electronic current transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100535622A CN101183606B (en) | 2007-10-15 | 2007-10-15 | Electronic current transformer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101183606A CN101183606A (en) | 2008-05-21 |
| CN101183606B true CN101183606B (en) | 2010-09-08 |
Family
ID=39448819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007100535622A Expired - Fee Related CN101183606B (en) | 2007-10-15 | 2007-10-15 | Electronic current transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101183606B (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101404404B (en) * | 2008-11-19 | 2011-08-03 | 马云涌 | Demarcation breaker for vector-synthesis zero sequence current |
| CN101806822B (en) * | 2010-02-24 | 2012-05-23 | 陈津 | Structure of high-voltage photoelectric conversion current sensor |
| CN101916647B (en) * | 2010-08-23 | 2011-12-07 | 山东电力研究院 | Multiband measurement digital linear alternating current transformer and measuring method thereof |
| CN102082607B (en) * | 2010-11-30 | 2014-04-16 | 株洲变流技术国家工程研究中心有限公司 | High resolution analog quantity optical fiber conversion method and converter with biasing circuit |
| CN102128966B (en) * | 2011-01-11 | 2012-07-11 | 沈阳互感器有限责任公司 | Rogowski coil-based integrator circuit for electronic current transformer |
| CN102436897B (en) * | 2011-09-15 | 2014-01-29 | 西安交通大学 | A flexible Rogowski coil for DC system short-circuit current detection and its design method |
| CN102998503B (en) * | 2012-11-16 | 2015-01-21 | 许继集团有限公司 | Mutual inductor electronic unit, electronic mutual inductor and replacing method of electronic unit |
| CN102967742B (en) * | 2012-12-06 | 2016-04-06 | 南京匹瑞电气科技有限公司 | The electric mutual inductor of wide current detection range |
| CN103473112B (en) * | 2013-09-03 | 2016-03-30 | 北京邮电大学 | A kind of calamity based on center, two places three is for information system simulation method |
| CN103812496A (en) * | 2014-01-27 | 2014-05-21 | 中国南方电网有限责任公司超高压输电公司百色局 | Hybrid optical direct-current measuring system on-site converter |
| CN104122428B (en) * | 2014-08-04 | 2017-02-22 | 青岛科汇电气有限公司 | Electronic current transformer adopting optical fiber to transmit analog signals |
| CN104104443B (en) * | 2014-08-04 | 2017-01-25 | 山东科汇电力自动化股份有限公司 | Method and device for transmitting analog electrical signal through optical fiber |
| CN104215827A (en) * | 2014-09-11 | 2014-12-17 | 谭成忠 | Alternating current sensor |
| CN108680888A (en) * | 2018-06-11 | 2018-10-19 | 中国电力科学研究院有限公司 | The method and system of all-fiber current transformator accuracy under a kind of low temperature disconnection fault |
| CN109387803B (en) * | 2018-10-10 | 2020-10-27 | 山东理工大学 | Current Transformer Signal Processing System and Method for Improving Small Current Measurement Accuracy |
| CN111198288A (en) * | 2020-02-17 | 2020-05-26 | 中国人民解放军海军工程大学 | High-voltage signal acquisition system based on optical fiber transmission and acquisition method thereof |
| CN112098704B (en) * | 2020-08-07 | 2023-08-29 | 国网山东省电力公司青岛供电公司 | Passive optical fiber current transformer and working method thereof |
| CN113315104B (en) * | 2021-07-14 | 2022-05-17 | 保定钰鑫电气科技有限公司 | Method for reducing differential protection misoperation |
-
2007
- 2007-10-15 CN CN2007100535622A patent/CN101183606B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101183606A (en) | 2008-05-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101183606B (en) | Electronic current transformer | |
| CN101413995B (en) | Apparatus for checking electronic type current mutual inductor | |
| CN103837852A (en) | All-fiber electronic current transformer frequency characteristic testing device and testing method | |
| CN101604142B (en) | Time information detection method of output signal of satellite synchronous timing device | |
| CN109407033B (en) | A calibration device for DC transformer transient calibrator | |
| CN108872921A (en) | Device and method for verifying broadband characteristics of direct current transformer | |
| CN110488216A (en) | A kind of digital output DCVT field calibration system | |
| CN104007346B (en) | Analog quantity merging unit transient state delay test method based on frequency scanning | |
| CN101770006A (en) | Novel method for checking electronic transducer | |
| CN107677982A (en) | A kind of digitalized electrical energy meter on-site calibrating method and device | |
| CN105548769A (en) | Relay protection action delay time grading test system and method | |
| CN104155545A (en) | Multichannel analog quantity acquisition module based on GPS signals | |
| CN102175923A (en) | Transmission line dynamic loss measurement system and method | |
| CN106646334A (en) | Method and system for calculating metering error of electric energy meter | |
| CN100585759C (en) | Broadband high voltage intelligent resistive voltage and current combination sensor | |
| CN201955465U (en) | Electronic transformer test system | |
| CN103905045B (en) | Alternating-current analog-digital conversion device real-time response detection method based on physical layer sampled value | |
| CN103399255B (en) | A kind of method of pseudo-random sequence identification Winding in Power Transformer state | |
| CN204903668U (en) | Intelligent substation small -signal communication simulation merging cells accuracy test equipment | |
| CN104597424B (en) | A kind of optical transformer electrical energy measurement verification platform and verification method | |
| CN201262889Y (en) | Electronic current transformer | |
| CN201859212U (en) | Novel calibration device of electronic type mutual inductor | |
| CN116338558B (en) | DC voltage broadband digital quantity standard device and use method thereof | |
| CN104635027A (en) | Electronic current transformer data acquisition system | |
| CN208937697U (en) | A device for verifying broadband characteristics of DC current transformers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100908 Termination date: 20211015 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |