CN101556320B - On-site calibrating method and device of capacitor voltage transformer - Google Patents

On-site calibrating method and device of capacitor voltage transformer Download PDF

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CN101556320B
CN101556320B CN2009101116729A CN200910111672A CN101556320B CN 101556320 B CN101556320 B CN 101556320B CN 2009101116729 A CN2009101116729 A CN 2009101116729A CN 200910111672 A CN200910111672 A CN 200910111672A CN 101556320 B CN101556320 B CN 101556320B
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杨成
理查德·道林
陈耀高
林玉涵
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Red phase Limited by Share Ltd
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Abstract

The invention relates to an on-site calibrating method and an on-site calibrating device of a capacitor voltage transformer. The invention directly measures voltage and current signals at the primary side and the secondary side of the measured capacitor voltage transformer and calculates the ratio and angular differences of the measured capacitor voltage transformer by utilizing the measured result, so that the invention can realize separately measuring the error of the measured capacitor voltage transformer only by the on-site calibrating device of the capacitor voltage transformer and does not need equipment such as a standard transformer, a voltage regulator, a voltage booster, a reactor and the like, thus saving calibrating time, lowering labor intensity of workers and resolving the difficulty of difficult implementation for error test of the on-site capacitor voltage transformer.

Description

The capacitance type potential transformer on-site calibrating method
Technical field
The present invention relates to a kind of capacitance type potential transformer on-site calibrating method, be mainly used in the site error test of metering with capacitance type potential transformer.
Background technology
Conventional capacitance type potential transformer field-checking mainly adopts relative method to carry out, and calibration equipment mainly is made up of standard potential transformer, the source of boosting (device), load box.During field-checking, the utilization source (device) of boosting simultaneously provides trial voltage to standard mutual inductor and winding of measured capacitance formula voltage transformer (VT), Secondary Winding with standard potential transformer is output as true value then, calculates or measure the output error of measured capacitance formula voltage transformer secondary winding.The calibration equipment of this on-site calibrating method is bulky, heavy, the field wiring complexity, cause the verification working time long, efficient is low, is difficult to satisfy that capacitance type potential transformer is in enormous quantities, the needs of efficient in-situ error testing.
Summary of the invention
The objective of the invention is to solve that existing capacitance type potential transformer field-checking equipment volume is huge, heavy, the present situation of inefficiency, propose a kind of capacitance type potential transformer on-site calibrating method that can significantly reduce the calibration equipment weight and volume.
A kind of capacitance type potential transformer on-site calibrating method specifically may further comprise the steps:
Step 1, first signal processor by calibration equipment apply two AC test signals V respectively between the capacitor cell high-pressure side of measured capacitance formula voltage transformer (VT) and electromagnetic unit low voltage terminal 11, V 12, the secondary side open circuit;
The secondary signal processor of step 2, this calibration equipment tests out the voltage signal of secondary side terminal respectively; According to difference, the nominal transformation ratio value of test voltage that applies and voltage that secondary side is surveyed, wherein nominal transformation ratio K R=V P/ V S, V PBe rated voltage, V SBe the secondary rated voltage, this rated voltage is imported by the operator, calculates measured capacitance formula voltage transformer (VT) respectively at these two test voltage point V 11, V 1No-load error under 2 and actual no-load voltage ratio K 1
Step 3, after the every unloaded parameter testing of completing steps 2, first signal processor applies test voltage V at primary side 12 o'clock, this calibration equipment was incorporated secondary load Z at secondary side automatically l,, calculate at test voltage point V according to the method for step 2 12 and secondary load Z lError under the state;
Step 4, described carrier wave end, electromagnetic unit low voltage terminal are disconnected capacitor cell high-pressure side and carrier wave end short circuit; It is V ' that first signal processor applies an AC test signals value in primary side capacitor cell high-pressure side and electromagnetic unit low voltage terminal, the secondary side open circuit, and it is V that the secondary signal processor is measured voltage signal values at secondary side 2', can obtain the actual no-load voltage ratio K of measured capacitance formula voltage transformer (VT) electromagnetism 2=V '/V 2';
Step 5, primary side capacitor cell high-pressure side, electromagnetic unit low voltage terminal, carrier wave end open circuit, the actual no-load voltage ratio K that obtains according to test 1, K 2With formula E=4.44fN Φ, inject low frequency, small voltage test signal V from secondary side respectively by the secondary signal processor TP, test out at equivalent primary voltage V 11, V 1Once unloaded admittance under 2 test points
Figure GSB00000577530100021
According to above-mentioned no load test electrical voltage point V 11, V 1The difference of the no-load error under 2 and unloaded admittance are poor, try to achieve the primary circuit impedance Z 1
Step 6, sealing in secondary load Z lThe time, described according to step 5, testing out secondary load respectively is Z lThe time, equivalent primary voltage is V 12, V TPAn admittance value under the point, calculating at secondary load is Z l, equivalent primary voltage is V TP, V 1Admittance in the time of 2 is poor;
By Z l, V TPPoint and Z l, V 1Admittance under 2 is poor, the primary circuit impedance Z 1, and secondary load Z l, voltage is V 12 error can calculate at load Z l, equivalent primary voltage V TPUnder ratio f and angular difference δ;
Step 7, by changing different secondary load Z lWith inject different low frequency, small voltage V at secondary side TP, can test out ratio f and angular difference δ under different load, the different electrical voltage point, thereby finish the field-checking of this capacitance type potential transformer.
Adopt the test signal avoid power frequency in described step 1,2,3,4, final testing result is converted into test result under the power frequency by frequency curve.
The present invention calculates the parameter that influences the capacitance type potential transformer error at measured capacitance formula voltage transformer (VT) primary side and the direct measuring voltage of secondary side, current signal.And utilize its test result calculations to go out the ratio and the angular difference of tested mutual inductor.Therefore a kind of capacitance type potential transformer on-site calibrating method of the present invention does not need equipment such as standard mutual inductor, pressure regulator, stepup transformer, reactor, only need can realize the error of this measured capacitance formula voltage transformer (VT) of independent measurement by the capacitance type potential transformer on-site calibration device among the present invention, save test period, reduce the test voltage signal, reduce intensity of workers, solved the difficulty that on-the-spot capacitance type potential transformer error test is difficult for enforcement, adopt the alien frequencies technology simultaneously, strengthened antijamming capability.
Description of drawings
Fig. 1 is a capacitance type potential transformer verification principle schematic of the present invention;
Fig. 2 is a capacitance type potential transformer schematic equivalent circuit of the present invention.
The invention will be further described below in conjunction with the drawings and specific embodiments.
Embodiment
As shown in Figure 1, wherein C1, C2 are the capacitance partial pressure unit, and T is an electromagnetic unit, L KBe compensation reactor, a, n are the metering winding, and da, dn are protection winding, Z XBe damping unit, P1 is the capacitor cell high-pressure side of measured capacitance formula voltage transformer (VT), and N is the carrier wave end of measured capacitance formula voltage transformer (VT), and E is the electromagnetic unit low voltage terminal.
A kind of capacitance type potential transformer on-site calibrating method of the present invention mainly comprises the steps:
First signal processor 1 of step 1, calibration equipment applies two AC test signals V that are no more than 3kV respectively between the capacitor cell high-pressure side P1 of measured capacitance formula voltage transformer (VT) and electromagnetic unit low voltage terminal E 11, V 12, the secondary side open circuit;
The secondary signal processor 2 of step 2, this calibration equipment tests out the voltage signal V of secondary side terminal respectively 21, V 22, and according to ε=f+jB, f=(K R* V 2-V 1)/V 1* 100%, jB=∠ V 2-∠ V 1(nominal transformation ratio K wherein R=V P/ V S, V PBe rated voltage, V SFor the secondary rated voltage is imported by keyboard by the operator); Calculate measured capacitance formula voltage transformer (VT) at V 11, V 1No-load error ε under 2 electrical voltage points Kv1, ε Kv2With actual no-load voltage ratio k 1=V 12/V 22;
Step 3, after testing the every unloaded parameter of step 2, calibration equipment is incorporated secondary load Z at secondary side automatically l, first signal processor 1 applies V at primary side 1During 2 voltages, the method according to step 2 calculates at V 1Under 2 electrical voltage points, secondary load is Z lError ε V2
Step 4, the carrier wave end N among Fig. 1 end, electromagnetic unit low voltage terminal E holds disconnections, capacitor cell high-pressure side P1 end and carrier wave end N hold short circuit.
Because damping unit Z XImpedance only just is attempted by when resonance occurring on protection winding da, the dn, can ignore when calculating measured capacitance formula voltage transformer (VT) precision.Therefore can equivalence be the measured capacitance formula voltage transformer (VT) equivalent circuit of Fig. 2.X among Fig. 2 CBe the equivalent reactance of equivalent capacitance (C1+C2), X KBe compensation reactor, X T1, X T2' be the leakage reactance (converting primary side) of measured capacitance formula voltage transformer (VT) one Secondary Winding, R 1Be winding of measured capacitance formula voltage transformer (VT) and compensation reactor direct current resistance and capacitive divider loss substitutional resistance sum R 1=(R C+ R K+ R T1), R 2' be that measured capacitance formula voltage transformer secondary winding is converted direct current resistance once, Z mExcitation impedance for measured capacitance formula voltage transformer (VT).
Thus, according to shown in Figure 2, first signal processor 1 applies an AC test signals V ' who is no more than 3kV at primary side P1, E end, the secondary side open circuit, and secondary signal processor 2 is measured voltage signal V at secondary side 2', can obtain the actual no-load voltage ratio K of measured capacitance formula voltage transformer (VT) 2=V '/V 2'.
Step 5, primary side capacitor cell high-pressure side, electromagnetic unit low voltage terminal, carrier wave end open circuit.According to V 11=K 1* V 21, V 12=K 1* V 22; V ' 1=K 2* V 2(V ' wherein 1Be the voltage between carrier wave end and the electromagnetic unit low pressure end), guaranteeing V ' 1Under power frequency component less than 3kV, according to different K 1, K 2, using formula E=4.44fN Φ injects low frequency, small voltage test signal V from secondary side respectively by the secondary signal processor TP, test out at equivalent primary voltage V 11, V 1Once unloaded admittance under 2 test points
Figure GSB00000577530100041
According to Δ ε k=ε Kv1-ε Kv2 With
Figure GSB00000577530100043
Try to achieve the primary circuit impedance Z 1
Step 6, inject low frequency, small voltage test signal V from secondary side respectively when the secondary signal processor TPAnd sealing in secondary load Z lThe time, described according to step 5, testing out secondary load respectively is Z lThe time, equivalent primary voltage is V 12, V TPExcitation admittance value Y under the point V2, Y TP, calculate admittance difference Δ Y TP=Y TP-Y V2
By formula Δ ε TP=Δ Y TP* Z 1, ε TP=Δ ε TP+ ε V2, ε TP=f TP+ j δ TPCan calculate at Z l, V TPUnder ratio f and angular difference δ.
Step 7, by changing different secondary load Z lLow frequency, small voltage signal V with the secondary side injection TP, can test out ratio f and angular difference δ under different load, the different electrical voltage point, thereby finish the field-checking of this capacitance type potential transformer.
This calibration equipment adopts the test signal of avoiding power frequency in step 1,2,3,4, final testing result is converted into test result under the power frequency by frequency curve, therefore has very strong anti-on-the-spot interference performance.
The present invention is at measured capacitance formula voltage transformer (VT) primary side and the direct measuring voltage of secondary side, current signal, and utilizes its test result calculations to go out the ratio and the angular difference of tested mutual inductor.Therefore a kind of capacitance type potential transformer on-site calibrating method of the present invention does not need equipment such as standard mutual inductor, pressure regulator, stepup transformer, reactor, only need can realize the error of this measured capacitance formula voltage transformer (VT) of independent measurement by the capacitance type potential transformer on-site calibration device among the present invention, save test period, reduce the test voltage signal, reduce intensity of workers, solved the difficulty that on-the-spot capacitance type potential transformer error test is difficult for enforcement, adopt the alien frequencies technology simultaneously, strengthened antijamming capability.
This calibration equipment mainly comprises first signal processor 1, secondary signal processor 2, amplification filtering unit 3, microprocessor 4, display screen 5, input media 6, data storage cell 7 and internal load unit 8;
Wherein this first signal processor 1 is used for the voltage, the current value that apply AC test signals and measure this access testing source between capacitor cell high-pressure side P1, carrier wave end and the electromagnetic unit low voltage terminal E of measured capacitance formula voltage transformer (VT) primary side;
This secondary signal processor 2 is used for measuring the magnitude of voltage of secondary side terminal when first signal processor 1 applies AC test signals and secondary side open circuit between the capacitor cell high-pressure side P1 of measured capacitance formula voltage transformer (VT) primary side and electromagnetic unit low voltage terminal E; When primary side capacitor cell high-pressure side P1, electromagnetic unit low voltage terminal E, carrier wave end N open circuit, at secondary side output low frequency, small voltage signal, and the current value of measurement secondary circuit;
When field-checking, according to the parameter situation of measured capacitance formula voltage transformer (VT), the size of the test voltage value that is applied by microprocessor 4 control first signal processor 1; The size of the secondary load unit that the access load value control internal load unit 8 that microprocessor 4 is selected according to preset value or operator is incorporated into; Microprocessor 4 injects corresponding low frequency, small voltage signal according to the test voltage point control secondary signal processor that preset value or client select at secondary side; This internal load unit is incorporated secondary side into automatically by microprocessor 4 controls; This amplification filtering unit 4 amplifies the signal of first signal processor 1 and secondary signal processor 2 outputs, send to microprocessor 4 after the filtering, after microprocessor 4 calculates and handles test result is shown on display screen 5; 7 of this input media 6 and data storage cells have been realized test parameter and the input of operator's instruction and the preservation and the processing of test result.

Claims (2)

1. capacitance type potential transformer on-site calibrating method is characterized in that specifically may further comprise the steps:
Step 1, first signal processor by calibration equipment apply two AC test signals V respectively between the capacitor cell high-pressure side of measured capacitance formula voltage transformer (VT) and electromagnetic unit low voltage terminal 11, V 12, the secondary side open circuit;
The secondary signal processor of step 2, this calibration equipment tests out the voltage signal of secondary side terminal respectively; According to difference, the nominal transformation ratio value of test voltage that applies and voltage that secondary side is surveyed, wherein nominal transformation ratio K R=V P/ V S, V PBe rated voltage, V SBe the secondary rated voltage, this rated voltage is imported by the operator, calculates measured capacitance formula voltage transformer (VT) respectively at these two test voltage point V 11, V 1No-load error under 2 and actual no-load voltage ratio K 1
Step 3, after the every unloaded parameter testing of completing steps 2, first signal processor applies test voltage V at primary side 12 o'clock, this calibration equipment was incorporated secondary load Z at secondary side automatically l,, calculate at test voltage point V according to the method for step 2 12 and secondary load Z lError under the state;
Step 4, described carrier wave end, electromagnetic unit low voltage terminal are disconnected capacitor cell high-pressure side and carrier wave end short circuit; It is V ' that first signal processor applies an AC test signals value in primary side capacitor cell high-pressure side and electromagnetic unit low voltage terminal, the secondary side open circuit, and it is V that the secondary signal processor is measured voltage signal values at secondary side 2', can obtain the actual no-load voltage ratio K of measured capacitance formula voltage transformer (VT) electromagnetism 2=V '/V 2';
Step 5, primary side capacitor cell high-pressure side, electromagnetic unit low voltage terminal, carrier wave end open circuit, the actual no-load voltage ratio K that obtains according to test 1, K 2With formula E=4.44fN Φ, inject low frequency, small voltage test signal V from secondary side respectively by the secondary signal processor TP, test out at equivalent primary voltage V 11, V 1Once unloaded admittance under 2 test points
Figure FSB00000577510000011
According to above-mentioned no load test electrical voltage point V 11, V 1The difference of the no-load error under 2 and unloaded admittance are poor, try to achieve the primary circuit impedance Z 1
Step 6, sealing in secondary load Z lThe time, described according to step 5, testing out secondary load respectively is Z lThe time, equivalent primary voltage is V 12, V TPAn admittance value under the point, calculating at secondary load is Z l, equivalent primary voltage is V TP, V 1Admittance in the time of 2 is poor;
By Z l, V TPPoint and Z l, V 1Admittance under 2 is poor, the primary circuit impedance Z 1, and secondary load Z l, voltage is V 12 error can calculate at load Z l, equivalent primary voltage V TPUnder ratio f and angular difference δ;
Step 7, by changing different secondary load Z lWith inject different low frequency, small voltage V at secondary side TP, can test out ratio f and angular difference δ under different load, the different electrical voltage point, thereby finish the field-checking of this capacitance type potential transformer.
2. capacitance type potential transformer on-site calibrating method according to claim 1 is characterized in that: adopt the test signal avoid power frequency in described step 1,2,3,4, final testing result is converted into test result under the power frequency by frequency curve.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1172261A (en) * 1997-08-27 1998-02-04 武汉国测电器公司 Method and device for checking electric power mutual inductor
US6060888A (en) * 1998-04-24 2000-05-09 Hewlett-Packard Company Error correction method for reflection measurements of reciprocal devices in vector network analyzers
CN101074988A (en) * 2007-07-20 2007-11-21 太原市优特奥科电子科技有限公司 Method and apparatus for realtime and on-line monitoring meter error of high-voltage mutual inductor
CN201402318Y (en) * 2009-04-30 2010-02-10 厦门红相电力设备股份有限公司 On-site checking device for capacitor voltage transformer

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1172261A (en) * 1997-08-27 1998-02-04 武汉国测电器公司 Method and device for checking electric power mutual inductor
US6060888A (en) * 1998-04-24 2000-05-09 Hewlett-Packard Company Error correction method for reflection measurements of reciprocal devices in vector network analyzers
CN101074988A (en) * 2007-07-20 2007-11-21 太原市优特奥科电子科技有限公司 Method and apparatus for realtime and on-line monitoring meter error of high-voltage mutual inductor
CN201402318Y (en) * 2009-04-30 2010-02-10 厦门红相电力设备股份有限公司 On-site checking device for capacitor voltage transformer

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