CN101187680A - AC power system voltage sensor - Google Patents

Abstract

The invention discloses a voltage sensor of an ac power system, which relates to a voltage signal acquisition device of the ac power system. The voltage sensor of the invention is composed of substation capacitive equipment, a current coil, an electronic transforming unit, an earth lead and a coaxial cable. The voltage sensor of the invention can work under industrial frequency AC circumstance for a long time and can bear big impulse voltage, output signals of the voltage sensor are separated thoroughly with an electrified wire netting though only once separation. The invention has the advantages of small volume, light weight, convenient installment. The preciseness of testing power frequency voltage signals can be reached to 1 grade, uncertainty of voltage peak values which are tested and operated is less then +-1%, the uncertainty of time parameters is in a range of +-3%, and thereby the invention can be applied to the collection of electric signals of an electric system 10kV to 500kV.

Description

A kind of AC power system voltage sensor

Technical field

The invention belongs to the power system voltage field tests, relate to a kind of deriving means of AC power system voltage signal.

Background technology

At present, traditional AC power system voltage sensor all is the electromagnetic potential sensor that adopts iron core coil structure, these voltage sensors utilize electromagnetic induction principle, and first and second slowdown monitoring circuit is isolated on electric, and the secondary device and the personal safety that make are protected.But they also have defective clearly: because ferromagnetic saturated, mutual inductor is measured the result and input value is non-property, and transient response is poor, can't measure for the overvoltage signal in the electric system; And volume is big, Heavy Weight.

High-voltage bleeder is also to be a kind of device that obtains voltage signal commonly used, mainly contains several versions such as resitstance voltage divider, capacitive divider and RC divider.Advantages such as high-voltage bleeder has simple in structure, and measuring accuracy is higher, and transient response is good.But the direct parallel high voltage operation of power networks of high-voltage bleeder has the contact of direct electricity between the height pressure arm, therefore must consider the safety problem of the person and measuring equipment especially; Once more, if apply to 110kV and above high-voltage fence, must consider that voltage divider is parallel to reliability of system operation, heating, impedance matching for a long time and exchanges a series of problems such as impact, this requirement to voltage divider is just strict more, and these have all limited the application of high-voltage bleeder in high-voltage fence; Simultaneously, the installation of voltage divider has also increased extra primary equipment input problem.

Domestic and international patent documentation is inquired about in online information retrieval, and application number is 01129750.6 Chinese patent, disclosed " a kind of capacitive divided voltage sensor ".This sensor is made up of one-time electrode, second electrode, ground-electrode, insulating material, terminal, secondary terminal, base plate, interface relay and a metallic shield, wherein, one-time electrode, second electrode and ground-electrode are made with metal circular tube, isolate with insulating material between them, one-time electrode mediates, second electrode is round one-time electrode, ground-electrode is arranged on the interface relay, second electrode connecting interface relay, ground-electrode are connected in the neutral point or the earth point of electric system.Be applied in the electric system of 10kV level, the high voltage of primary side is transformed to the secondary side low-voltage linearly, as the technology of the information about power conversion of measurement, protection and the input of control system information.This sensor is to carry out capacitance partial pressure by the distributed capacitance that voltage and interelectrode induction field form in essence, because electromagnetic interference (EMI) is very big in the transformer station of high-voltage fence, the distributed capacitance of the various device in the transformer station is interactive, therefore the size of dividing potential drop electric capacity is subjected to ectocine easily and changes, this just causes intrinsic standoff ratio non-constant, must cause measuring error, this has influence on this sensor application and reaches more voltage levels electrical network to 110kV.

Summary of the invention

The objective of the invention is to overcome above-mentioned the deficiencies in the prior art, a kind of AC power system voltage sensor is provided.

The principle of work of a kind of AC power system voltage sensor involved in the present invention is: the capacitive equipment that directly utilizes transformer station, adopt the current signal over the ground of the current sensor measurement capacitive apparatus of high precision broad frequency, by mimic channel current signal is carried out integral transformation then, with the reconstruct mains voltage signal.In circuit system model shown in Figure 1, C _PBe capacitive apparatus equivalent capacity, R _PBe the capacitive apparatus equivalent resistance, when the capacitive apparatus medium is good, R _PBe worth very big, capacitive apparatus can the equivalence a pure capacitor C _P

If line voltage is u ₁(t), when it acts on the capacitive apparatus, it to vagabond current is:

$i_1\left(t\right)=C_P\frac{{\mathrm{du}}_1\left(t\right)}{\mathrm{dt}}$

If the no-load voltage ratio of current sensor is K, its output voltage is:

$u_d\left(t\right)=R_d{i}_2\left(t\right)=K{C}_P\frac{{\mathrm{du}}_1\left(t\right)}{\mathrm{dt}}$

Through integration constant is T _iIntegrator after output voltage be:

$u_2\left(t\right)=\frac{1}{T_i}{\∫u}_d\left(t\right)\mathrm{dt}=\frac{{\mathrm{KC}}_p}{T_i}{u}_1\left(t\right)$

Because K, C _PAnd T _iBe constant, so the output voltage of voltage sensor and line voltage are linear, hence one can see that, and a kind of AC power system voltage sensor involved in the present invention can be monitored the voltage signal of AC electric power systems.

Realize that technical scheme of the present invention is as follows:

A kind of AC power system voltage sensor, it is characterized in that: form by transformer station's capacitive apparatus 1, current coil 2, electronics converter unit 3, earth lead 4, concentric cable 5, earth lead 4 one ends link to each other with the end screen of capacitive apparatus, the other end passes current coil 2 ground connection, be connected by concentric cable 5 between current coil 2 output ports and electronics converter unit 3 input ports, the output of electronics converter unit 3 is received on the third-party harvester by concentric cable 5; Current coil 2 is by the nanometer crystal alloy annular core, winding, double-layer shielding structure, screening can and coaxial fitting are formed, in screening can, winding is set respectively from the inside to the outside, nanometer crystal alloy annular core and double-layer shielding structure, winding is on the nanometer crystal alloy annular core, double-layer shielding structure be arranged on coil on, downside and lateral surface, the internal layer of double-layer shielding structure is a copper sheet, skin is an iron sheet, thickness is 0.3mm～0.5mm, filled polytetrafluoroethylene film between two screen layers, all there is the wide vertical fluting of 1mm～1.5mm in the outside of two screen layers, coaxial fitting is arranged on the lateral surface of engineering plastics shell, and the winding two ends link to each other with the coaxial fitting two ends respectively; Electronic accumulation converter unit 3 is by electronic circuit board 6, stainless steel shielding box 7 and screw 8 are formed, electronic circuit board 6 is fixed in the stainless steel shielding box 7 by screw 8, comprise the I/V converter unit on the electronic circuit board 6, integrating circuit and power conversion, the I/V translation circuit comprises the front-end protection circuit, operational amplifier, coaxial fitting, resistance and electric capacity, holding circuit is by diode D1, D2 forms, the 8th pin of operational amplifier U1 meets the positive 12V of power supply, the 4th pin meets power-12V, heart yearn connecting resistance R1 one end of input cable splice B1, the external ground of B1, second pin of inverting input of resistance R 1 another termination operational amplifier U1, the anode of second pin of the inverting input of operational amplifier U1 and diode D1, the negative electrode of D2, one end of resistance R 2 and capacitor C 1 links to each other, the negative electrode of diode D1, the anode of D2 links to each other with ground, the other end of resistance R 2 and capacitor C 1 links to each other with first pin output terminal of operational amplifier U1, the 3rd pin of the in-phase input end of one termination operational amplifier U1 of resistance R 3, other end ground connection, the 5th pin of the in-phase input end of operational amplifier U1 and capacitor C 2, one end of resistance R 4 links to each other, the other end of capacitor C 2 is received first pin of operational amplifier U1, the other end ground connection of resistance R 4, the 6th pin of the inverting input of operational amplifier U1 links to each other with the 7th pin; Analogue integrator comprises operational amplifier, cable splice, resistance and electric capacity, the output of I/V conversion is received in the signal input of integrator by lead, the output of I/V conversion is received in the signal input of integrator by lead, signal output cable B2 heart yearn is received in the output of integrator, the pin eight of operational amplifier U2 in the integrator links to each other with the positive 12V of power supply, pin four links to each other with voltage negative 12V, inverting input pin two and the resistance R 5 of U2, R6, one end of capacitor C 3 links to each other, the other end of resistance R 5 is linked on the output pin seven of operational amplifier U1, the other end of resistance R 6 links to each other with the other end of capacitor C 3, receive on the output pin one of operational amplifier U2, one end of resistance R 7 links to each other with the in-phase input end pin three of operational amplifier U2, other end ground connection, one end of capacitor C 4 links to each other with an end of resistance R 8, receive on the in-phase input end pin five of operational amplifier U2, the other end of capacitor C 4 links to each other with the output terminal pin one of operational amplifier U2, the other end ground connection of resistance R 8, the inverting input pin six of operational amplifier U2 links to each other with output pin seven, receive signal output concentric cable B2 heart yearn, the earthing of casing of concentric cable B2; Power converting circuit becomes that operational amplifier needs ± the 12V power supply with the 5V power conversion of input, it comprises a power input interface and a DC/DC transducer, the input pin one of the positive pole of 5V power supply and DC/DC module U3,24 link to each other, the input grounding end pin 12 of negative pole and DC/DC module U3,13 link to each other, the positive pole of electric capacity E1 and U3+12V output pin the 11, the 14 pin links to each other, the positive pole of electric capacity E2 and DC/DC module U3-12V output pin second, the 20 three-prong links to each other, electric capacity E2, the output earth terminal pin the 3rd of the negative pole of E3 and DC/DC module U3, ten, 12,15 pins link to each other.

After the present invention adopts technique scheme, can long-term work in the industrial frequency AC environment, and can bear bigger surge voltage, mainly contain following characteristics:

1, a kind of AC power system voltage sensor of the present invention directly utilizes the differentiation element of the capacitive apparatus of transformer station as voltage sensor, has avoided in electrical network a dividing potential drop equipment is installed and brings potentiality danger to electrical network;

2, a kind of AC power system voltage sensor of the present invention by the current sensor measurement capacitive apparatus over the ground current signal measure mains voltage signal, current sensor adopts the Rogowski loop construction, the once complete electrical isolation of signal of sensor and electrical network has good security feature;

3, a kind of AC power system voltage sensor of the present invention is simple in structure, links such as the current sensor of required design and electronic integrator have volume little, in light weight, be convenient to advantages such as installation;

4, a kind of AC power system voltage sensor measurement power-frequency voltage signal of the present invention and internal overvoltage signal have better linearity degree and precision, test shows, sensor measurement power-frequency voltage signal accuracy can reach 1 grade, the superpotential peak value uncertainty of measuring operation in ± 1%, time parameter uncertain in ± 3% scope.

5, a kind of AC power system voltage sensor of the present invention has good versatility, can make sensor application in the different electric pressure of 10-500kV by the circuit parameter of adjusting current sensor and integral transformation unit very easily.

Description of drawings

Fig. 1 is a voltage sensor structural representation of the present invention;

Fig. 2 is that the ideal of voltage sensor of the present invention is simplified circuit model;

Fig. 3 is the circuit theory diagrams of electronic circuit converter unit in the voltage sensor of the present invention;

Fig. 4 is for measuring the industrial-frequency alternating current corrugating relatively;

Fig. 5 measures the linearity curve map of power frequency ac voltage for voltage sensor of the present invention

The waveform that Fig. 6 impacts for measuring operation compares;

Fig. 7 is the linearity curve map of measuring operation surge voltage peak value;

1 is transformer station's capacitive apparatus among the above-mentioned figure, 2 is current coil, 3 is the electronic circuit converter unit, 4 is the bottom shielding of bushing ground wire, and 5 is concentric cable, and 6 is that electronic circuit board, 7 is screw for stainless steel shields box, 8, A is that capacitive divider is measured power frequency voltage waveform, B is that voltage sensor of the present invention is measured power frequency voltage waveform, and C is a capacitive divider measuring operation over-voltage waveform, and D is a voltage sensor measuring operation over-voltage waveform of the present invention.

Embodiment

Below in conjunction with drawings and Examples, the present invention is further described as follows:

Embodiment 1

Shown in Fig. 1～3: a kind of 110kV AC power system voltage sensor, comprise 110kV transformer capacitance graded bushing 1, current coil 2, electronics converter unit 3, bottom shielding of bushing earth lead 4, concentric cable 5, the end screen of earth lead 4 one termination transformer capacitance graded bushings 1, the other end pass current coil 2 ground connection, be connected by concentric cable 5 between current coil 2 and the electronics converter unit 3, the output of electronics converter unit 3 outputs to third-party harvester by concentric cable.Current coil 2 is made up of nanometer crystal alloy annular core, winding, double-layer shielding structure, screening can and coaxial fitting, in screening can, it is winding, nanometer crystal alloy annular core and the double-layer shielding structure of 200 circles by the number of turn of the enameled wire coiling of diameter 0.19mm that winding is set respectively from the inside to the outside, winding is on the nanometer crystal alloy annular core, double-layer shielding structure is arranged on the upper and lower side and the lateral surface of coil, the internal layer of double-layer shielding structure is a copper sheet, outer for iron sheet, thickness are 0.5mm, in order to the shielding outside electromagnetic interference; Filled polytetrafluoroethylene film between two screen layers is in order to the electrical link of isolated two screen layers; All there is the wide vertical fluting of 1.5mm in the outside of two screen layers, produces in order to prevent eddy current; Coaxial fitting is arranged on the lateral surface of engineering plastics shell.Electronic accumulation converter unit 3 is made up of electronic circuit board 6, stainless steel shielding box 7, screw 8 and coaxial fitting, and electronic circuit board 6 is fixed in the stainless steel shielding box 7 by screw 8, and coaxial fitting is arranged on the lateral surface of stainless steel shielding box 7; Circuit comprises I/V converter unit, integrating circuit and power conversion on the electronic circuit board 6; The I/V translation circuit comprises front-end protection circuit, operational amplification circuit U and resistance, electric capacity; The front-end protection circuit is made up of diode D1, D2, and the model of D1, D2 is 1N4007, and the model of operational amplifier U1 is AD712, and resistance R 1 resistance is 0 Europe, and the resistance of resistance R 2, R3 and R4 is respectively 2k, 2k and 1M, and capacitor C 1 is 20pF, and C2 is 0.1uF.The octal of U1 meets the positive 12V of power supply, four pin meet power-12V, heart yearn connecting resistance R1 one end of input cable B1, external ground, the inverting input pin two of resistance R 1 another termination operational amplifier U1, the inverting input pin two of operational amplifier U1 links to each other with an end of negative electrode, resistance R 2 and the capacitor C 1 of the anode of diode D1, D2, the negative electrode of diode D1 links to each other with ground with the anode of D2, and the other end of resistance R 2 and capacitor C 1 links to each other with the output terminal pin one of operational amplifier U1; One of resistance R 3 terminates to the in-phase input end pin three of operational amplifier U1, the other end is linked ground, the in-phase input end pin five of operational amplifier U1 links to each other with an end of capacitor C 2, resistance R 4, the other end of capacitor C 2 is connected to the output pin five of operational amplifier U1, the other end ground connection of resistance R 4, the inverting input pin six of operational amplifier U1 links to each other with output pin seven; Analogue integrator comprises that analogue integrator comprises operational amplifier, cable splice, resistance and electric capacity, and the model of operational amplifier U2 is AD712, and resistance R 5 and R7 are 1k, and R6 and R8 are 1M, and C3 and C4 are 0.1uF; The output of I/V conversion is received in the signal input of integrator by lead, signal output cable B2 heart yearn is received in the output of integrator, the pin eight of operational amplifier U2 in the integrator links to each other with+12V power supply, pin four links to each other with-12V voltage, inverting input pin two and the resistance R 5 of U2, R6, one end of capacitor C 3 links to each other, the other end of resistance R 5 is linked on the output pin seven of operational amplifier U1, the other end of resistance R 6 links to each other with the other end of capacitor C 3, receive on the output pin one of operational amplifier U2, one end of resistance R 7 links to each other with the in-phase input end pin three of operational amplifier U2, other end ground connection, one end of capacitor C 4 links to each other with an end of resistance R 8, receive on the in-phase input end pin five of operational amplifier U2, the other end of capacitor C 4 links to each other with the output terminal pin one of operational amplifier U2, the other end ground connection of resistance R 8, the inverting input pin six of operational amplifier U2 links to each other with output pin seven, receives signal output concentric cable B2 heart yearn, the earthing of casing of concentric cable B2; Power converting circuit becomes that operational amplifier needs ± the 12V power supply with the 5V power conversion of input, it comprises a power input interface and a DC/DC transducer, the input pin one of the positive pole of 5V power supply and DC/DC module U3,24 link to each other, the input grounding end pin 12 of negative pole and DC/DC module U3,13 link to each other, the positive pole of electric capacity E1 and U3+12V output pin the 11, the 14 pin links to each other, the positive pole of electric capacity E2 and DC/DC module U3-12V output pin second, the 20 three-prong links to each other, electric capacity E2, the output earth terminal pin the 3rd of the negative pole of E3 and DC/DC module U3, ten, 12,15 pins link to each other.

Embodiment 2

Shown in Fig. 1～3: a kind of 110kV AC power system voltage sensor, comprise 110kV condenser type current transformer 1, current coil 2, electronics converter unit 3, bottom shielding of bushing earth lead 4, concentric cable 5, the end screen of earth lead 4 one termination capacitor formula current transformers 1, the other end pass current coil 2 ground connection, be connected by concentric cable 5 between current coil 2 and the electronics converter unit 3, the output of electronics converter unit 3 outputs to third-party harvester by concentric cable.Current coil 2 is made up of nanometer crystal alloy annular core, winding, double-layer shielding structure, screening can and coaxial fitting, in screening can, it is winding, nanometer crystal alloy annular core and the double-layer shielding structure of 500 circles by the number of turn of the enameled wire coiling of diameter 0.15mm that winding is set respectively from the inside to the outside, winding is on the nanometer crystal alloy annular core, double-layer shielding structure is arranged on the upper and lower side and the lateral surface of coil, the internal layer of double-layer shielding structure is a copper sheet, outer for iron sheet, thickness are 0.5mm, in order to the shielding outside electromagnetic interference; Filled polytetrafluoroethylene film between two screen layers is in order to the electrical link of isolated two screen layers; All there is the wide vertical fluting of 1mm in the outside of two screen layers, produces in order to prevent eddy current; Coaxial fitting is arranged on the lateral surface of engineering plastics shell.Electronic accumulation converter unit 3 is made up of electronic circuit board 6, stainless steel shielding box 7, screw 8 and coaxial fitting, and electronic circuit board 6 is fixed in the stainless steel shielding box 7 by screw 8, and coaxial fitting is arranged on the lateral surface of stainless steel shielding box 7; Circuit comprises I/V converter unit, integrating circuit and power conversion on the electronic circuit board 6; The I/V translation circuit comprises front-end protection circuit, operational amplification circuit U and resistance, electric capacity; The front-end protection circuit is made up of diode D1, D2, and the model of D1, D2 is 1N4007, and the model of operational amplifier U1 is AD712, and resistance R 1 resistance is 0 Europe, and the resistance of resistance R 2, R3 and R4 is respectively 1k, 1k and 1M, and capacitor C 1 is 20pF, and C2 is 0.1uF.The octal of U1 meets power supply+12V, four pin meet power supply-12V, heart yearn connecting resistance R1 one end of input cable B1, external ground, the inverting input pin two of resistance R 1 another termination operational amplifier U1, the inverting input pin two of operational amplifier U1 links to each other with an end of negative electrode, resistance R 2 and the capacitor C 1 of the anode of diode D1, D2, the negative electrode of diode D1 links to each other with ground with the anode of D2, and the other end of resistance R 2 and capacitor C 1 links to each other with the output terminal pin one of operational amplifier U1; One of resistance R 3 terminates to the in-phase input end pin three of operational amplifier U1, other end ground connection, the in-phase input end pin five of operational amplifier U1 links to each other with an end of capacitor C 2, resistance R 4, the other end of capacitor C 2 is connected to the output pin five of operational amplifier U1, the other end of resistance R 4 is linked ground, and the inverting input pin six of operational amplifier U1 links to each other with output pin seven; Analogue integrator comprises that analogue integrator comprises operational amplifier, cable splice, resistance and electric capacity, and the model of operational amplifier U2 is AD712, and resistance R 5 and R7 are 1k, and R6 and R8 are 1M, and C3 and C4 are 0.1uF; The output of I/V conversion is received in the signal input of integrator by lead, signal output cable B2 heart yearn is received in the output of integrator, the pin eight of operational amplifier U2 in the integrator links to each other with+12V power supply, pin four links to each other with-12V voltage, inverting input pin two and the resistance R 5 of U2, R6, one end of capacitor C 3 links to each other, the other end of resistance R 5 is linked on the output pin seven of operational amplifier U1, the other end of resistance R 6 links to each other with the other end of capacitor C 3, receive on the output pin one of operational amplifier U2, one end of resistance R 7 links to each other with the in-phase input end pin three of operational amplifier U2, other end ground connection, one end of capacitor C 4 links to each other with an end of resistance R 8, receive on the in-phase input end pin five of operational amplifier U2, the other end of capacitor C 4 links to each other with the output terminal pin one of operational amplifier U2, the other end ground connection of resistance R 8, the inverting input pin six of operational amplifier U2 links to each other with output pin seven, receives signal output concentric cable B2 heart yearn, the earthing of casing of concentric cable B2; Power converting circuit becomes that operational amplifier needs ± the 12V power supply with the 5V power conversion of input, it comprises a power input interface and a DC/DC transducer, the input pin one of the positive pole of 5V power supply and DC/DC module U3,24 link to each other, the input grounding end pin 12 of negative pole and DC/DC module U3,13 link to each other, the positive pole of electric capacity E1 and U3+12V output pin the 11, the 14 pin links to each other, the positive pole of electric capacity E2 and DC/DC module U3-12V output pin second, the 20 three-prong links to each other, electric capacity E2, the output earth terminal pin the 3rd of the negative pole of E3 and DC/DC module U3, ten, 12,15 pins link to each other.

Embodiment 3

Shown in Fig. 1～3: a kind of 110kV AC power system voltage sensor, comprise 110kV capacitance type potential transformer 1, current coil 2, electronics converter unit 3, bottom shielding of bushing earth lead 4, concentric cable 5, the end screen of earth lead 4 one terminal voltage mutual inductors 1, the other end pass current coil 2 ground connection, be connected by concentric cable 5 between current coil 2 and the electronics converter unit 3, the output of electronics converter unit 3 outputs to third-party harvester by concentric cable.Current coil 2 is made up of nanometer crystal alloy annular core, winding, double-layer shielding structure, screening can and coaxial fitting, in screening can, it is winding, nanometer crystal alloy annular core and the double-layer shielding structure of 600 circles by the number of turn of the enameled wire coiling of diameter 0.15mm that winding is set respectively from the inside to the outside, winding is on the nanometer crystal alloy annular core, double-layer shielding structure is arranged on the upper and lower side and the lateral surface of coil, the internal layer of double-layer shielding structure is a copper sheet, outer for iron sheet, thickness are 0.5mm, in order to the shielding outside electromagnetic interference; Filled polytetrafluoroethylene film between two screen layers is in order to the electrical link of isolated two screen layers; All there is the wide vertical fluting of 1mm in the outside of two screen layers, produces in order to prevent eddy current; Coaxial fitting is arranged on the lateral surface of engineering plastics shell.Electronic accumulation converter unit 3 is made up of electronic circuit board 6, stainless steel shielding box 7, screw 8 and coaxial fitting, and electronic circuit board 6 is fixed in the stainless steel shielding box 7 by screw 8, and coaxial fitting is arranged on the lateral surface of stainless steel shielding box 7; Circuit comprises I/V converter unit, integrating circuit and power conversion on the electronic circuit board 6; The I/V translation circuit comprises front-end protection circuit, operational amplification circuit U and resistance, electric capacity; The front-end protection circuit is made up of diode D1, D2, and the model of D1, D2 is 1N4007, and the model of operational amplifier U1 is AD712, and resistance R 1 resistance is 0 Europe, and the resistance of resistance R 2, R3 and R4 is respectively 1k, 1k and 1M, and capacitor C 1 is 20pF, and C2 is 0.1uF.The octal of U1 meets power supply+12V, four pin meet power supply-12V, heart yearn connecting resistance R1 one end of input cable B1, external ground, the inverting input pin two of resistance R 1 another termination operational amplifier U1, the inverting input pin two of operational amplifier U1 links to each other with an end of negative electrode, resistance R 2 and the capacitor C 1 of the anode of diode D1, D2, the negative electrode of diode D1 links to each other with ground with the anode of D2, and the other end of resistance R 2 and capacitor C 1 links to each other with the output terminal pin one of operational amplifier U1; One of resistance R 3 terminates to the in-phase input end pin three of operational amplifier U1, the other end is linked ground, the in-phase input end pin five of operational amplifier U1 links to each other with an end of capacitor C 2, resistance R 4, the other end of capacitor C 2 is connected to the output pin five of operational amplifier U1, the other end of resistance R 4 is linked ground, and the inverting input pin six of operational amplifier U1 links to each other with output pin seven; Analogue integrator comprises that analogue integrator comprises operational amplifier, cable splice, resistance and electric capacity, and the model of operational amplifier U2 is AD712, and resistance R 5 and R7 are 1k, and R6 and R8 are 1M, and C3 and C4 are 0.1uF; The output of I/V conversion is received in the signal input of integrator by lead, signal output cable B2 heart yearn is received in the output of integrator, the pin eight of operational amplifier U2 in the integrator links to each other with+12V power supply, pin four links to each other with-12V voltage, inverting input pin two and the resistance R 5 of U2, R6, one end of capacitor C 3 links to each other, the other end of resistance R 5 is linked on the output pin seven of operational amplifier U1, the other end of resistance R 6 links to each other with the other end of capacitor C 3, receive on the output pin one of operational amplifier U2, one end of resistance R 7 links to each other with the in-phase input end pin three of operational amplifier U2, other end ground connection, one end of capacitor C 4 links to each other with an end of resistance R 8, receive on the in-phase input end pin five of operational amplifier U2, the other end of capacitor C 4 links to each other with the output terminal pin one of operational amplifier U2, the other end ground connection of resistance R 8, the inverting input pin six of operational amplifier U2 links to each other with output pin seven, receives signal output concentric cable B2 heart yearn, the earthing of casing of concentric cable B2; Power converting circuit becomes that operational amplifier needs ± the 12V power supply with the 5V power conversion of input, it comprises a power input interface and a DC/DC transducer, the input pin one of the positive pole of 5V power supply and DC/DC module U3,24 link to each other, the input grounding end pin 12 of negative pole and DC/DC module U3,13 link to each other, the positive pole of electric capacity E1 and U3+12V output pin the 11, the 14 pin links to each other, the positive pole of electric capacity E2 and DC/DC module U3-12V output pin second, the 20 three-prong links to each other, electric capacity E2, the output earth terminal pin the 3rd of the negative pole of E3 and DC/DC module U3, ten, 12,15 pins link to each other.

Experimental result

Sensor to embodiment 1 carries out following test:

1, power frequency ac voltage experiment with measuring.Test method: become 20kV～200kV voltage to be added on the sleeve pipe power frequency 10kV voltage transformation with pressure regulator, adopt TCF2000/0.0012 type capacitive divider as gauge measurement system in the test, rated voltage 2000kV, specified intrinsic standoff ratio 3000: 1.

Fig. 4 is the duplex frequency voltage measuring waveform, and waveform A is voltage divider output result, and waveform B is that therefrom the output waveform of voltage sensor of the present invention is almost consistent with the output waveform of capacitive divider as can be seen for voltage sensor output result of the present invention.

The output linearity of Fig. 5 sensor of embodiment 1 when being 20kV～200kV at the input power-frequency voltage line chart of writing music, the linear fit degree 0.9993 of voltage sensor illustrates that the linearity was good when voltage sensor of the present invention was measured power-frequency voltage.

2, switching overvoltage experiment with measuring.Test method: produce the operation ripple with surge generator and be added on the sleeve pipe, adopt TCF2000/0.0012 type capacitive divider as gauge measurement system in the test, rated voltage 2000kV, specified intrinsic standoff ratio 3000: 1.

Fig. 6 is the switching impulse measured waveform, waveform C is capacitive divider output result, waveform D is embodiment voltage sensor output result, therefrom the output waveform of voltage sensor of the present invention is almost consistent with the output waveform of capacitive divider as can be seen, wherein the time parameter of the operation ripple of capacitive divider measurement is 146us/1940us, and the time parameter of the operation ripple that voltage sensor is measured is 146us/1930us.

Fig. 7 is at the switching impulse peak value being the linearity curve map of voltage sensor measurement peak value output under 100kV～320kV, the linear degree of fitting 0.9989 of the output of voltage sensor sensor has good linearty when the voltage sensor measuring operation is impacted as can be seen.

Principle and measurement result according to voltage sensor of the present invention show, a kind of AC power system voltage sensor of the present invention can long-term work in the industrial frequency AC environment, and can bear bigger surge voltage; The once complete electrical isolation of signal of sensor and electrical network; It is little to have volume, in light weight, be convenient to advantages such as installation; Measure the power-frequency voltage signal accuracy and can reach 1 grade, the superpotential peak value uncertainty of measuring operation in ± 1%, time parameter uncertain in ± 3% scope; So can be widely used in the collection of 10kV～500kV power system voltage signal.

Claims (4)

1. AC power system voltage sensor, it is characterized in that: form by transformer station's capacitive apparatus 1, current coil 2, electronics converter unit 3, earth lead 4, concentric cable 5, earth lead 4 one ends link to each other with the end screen of capacitive apparatus, the other end passes current coil 2 ground connection, be connected by concentric cable 5 between current coil 2 output ports and electronics converter unit 3 input ports, the output of electronics converter unit 3 is received on the third-party harvester by concentric cable 5; Current coil 2 is by the nanometer crystal alloy annular core, winding, double-layer shielding structure, screening can and coaxial fitting are formed, in screening can, winding is set respectively from the inside to the outside, nanometer crystal alloy annular core and double-layer shielding structure, winding is on the nanometer crystal alloy annular core, double-layer shielding structure be arranged on coil on, downside and lateral surface, the internal layer of double-layer shielding structure is a copper sheet, skin is an iron sheet, thickness is 0.3mm～0.5mm, filled polytetrafluoroethylene film between two screen layers, all there is the wide vertical fluting of 1mm～1.5mm in the outside of two screen layers, coaxial fitting is arranged on the lateral surface of engineering plastics shell, and the winding two ends link to each other with the coaxial fitting two ends respectively; Electronic accumulation converter unit 3 is by electronic circuit board 6, stainless steel shielding box 7 and screw 8 are formed, electronic circuit board 6 is fixed in the stainless steel shielding box 7 by screw 8, comprise the I/V converter unit on the electronic circuit board 6, integrating circuit and power conversion, the I/V translation circuit comprises the front-end protection circuit, operational amplifier, coaxial fitting, resistance and electric capacity, holding circuit is by diode D1, D2 forms, the 8th pin of operational amplifier U1 meets the positive 12V of power supply, the 4th pin meets power-12V, heart yearn connecting resistance R1 one end of input cable splice B1, the external ground of B1, second pin of inverting input of resistance R 1 another termination operational amplifier U1, the anode of second pin of the inverting input of operational amplifier U1 and diode D1, the negative electrode of D2, one end of resistance R 2 and capacitor C 1 links to each other, the negative electrode of diode D1, the anode of D2 links to each other with ground, the other end of resistance R 2 and capacitor C 1 links to each other with first pin output terminal of operational amplifier U1, the 3rd pin of the in-phase input end of one termination operational amplifier U1 of resistance R 3, other end ground connection, the 5th pin of the in-phase input end of operational amplifier U1 and capacitor C 2, one end of resistance R 4 links to each other, the other end of capacitor C 2 is received first pin of operational amplifier U1, the other end ground connection of resistance R 4, the 6th pin of the inverting input of operational amplifier U1 links to each other with the 7th pin; Analogue integrator comprises operational amplifier, cable splice, resistance and electric capacity, the output of I/V conversion is received in the signal input of integrator by lead, the output of I/V conversion is received in the signal input of integrator by lead, signal output cable B2 heart yearn is received in the output of integrator, the pin eight of operational amplifier U2 in the integrator links to each other with the positive 12V of power supply, pin four links to each other with voltage negative 12V, inverting input pin two and the resistance R 5 of U2, R6, one end of capacitor C 3 links to each other, the other end of resistance R 5 is linked on the output pin seven of operational amplifier U1, the other end of resistance R 6 links to each other with the other end of capacitor C 3, receive on the output pin one of operational amplifier U2, one end of resistance R 7 links to each other with the in-phase input end pin three of operational amplifier U2, other end ground connection, one end of capacitor C 4 links to each other with an end of resistance R 8, receive on the in-phase input end pin five of operational amplifier U2, the other end of capacitor C 4 links to each other with the output terminal pin one of operational amplifier U2, the other end ground connection of resistance R 8, the inverting input pin six of operational amplifier U2 links to each other with output pin seven, receive signal output concentric cable B2 heart yearn, the earthing of casing of concentric cable B2; Power converting circuit becomes that operational amplifier needs ± the 12V power supply with the 5V power conversion of input, it comprises a power input interface and a DC/DC transducer, the input pin one of the positive pole of 5V power supply and DC/DC module U3,24 link to each other, the input grounding end pin 12 of negative pole and DC/DC module U3,13 link to each other, the positive pole of electric capacity E1 and U3+12V output pin the 11, the 14 pin links to each other, the positive pole of electric capacity E2 and DC/DC module U3-12V output pin second, the 20 three-prong links to each other, electric capacity E2, the output earth terminal pin the 3rd of the negative pole of E3 and DC/DC module U3, ten, 12,15 pins link to each other.

2. according to the described a kind of AC power system voltage sensor of claim 1; it is characterized in that: transformer station's capacitive apparatus 1 adopts the transformer capacitance graded bushing of transformer station; the capacitance scope of capacitance graded bushing is 50～600pF; the winding of current coil 2 is that the number of turn of the enameled wire coiling of diameter 0.19mm is the winding of 200 circles; double layer screen thickness is 0.5mm; all there is the wide vertical fluting of 1.5mm in the outside of two screen layers; operational amplifier U1; U2 is AD712; the diode D1 of holding circuit; D2 is 1N4007; the resistance R 2 of I/V conversion is 2k; C1 is 20pF, and integrating resistor R5 is 1k in the integral transformation unit, and integrating capacitor C3 is 0.1uF.

3. according to the described a kind of AC power system voltage sensor of claim 1; it is characterized in that: transformer station's capacitive apparatus 1 adopts the condenser type current transformer; the capacitance scope of current transformer is 100～1000pF; the winding of current coil 2 is that the number of turn of the enameled wire coiling of diameter 0.15mm is the winding of 500 circles; double layer screen thickness is 0.5mm; all there is the wide vertical fluting of 1mm in the outside of two screen layers; operational amplifier U1; U2 is AD712; the diode D1 of holding circuit; D2 is 1N4007; the resistance R 2 of I/V conversion is 1k; C1 is 20pF, and integrating resistor R5 is 1k in the integral transformation unit, and integrating capacitor C3 is 0.1uF.

4. according to the described a kind of AC power system voltage sensor of claim 1; it is characterized in that: transformer station's capacitive apparatus 1 adopts capacitance type potential transformer; the capacitance scope of voltage transformer (VT) is 3000～5000pF; the winding of current coil 2 is the winding of 600 circles by the number of turn of the enameled wire coiling of diameter 0.15mm; double layer screen thickness is 0.5mm; all there is the wide vertical fluting of 1mm in the outside of two screen layers; operational amplifier U1; U2 is AD712; the diode D1 of holding circuit; D2 is 1N4007; the resistance R 2 of I/V conversion is 1k; C1 is 20pF, and integrating resistor R5 is 1k in the integral transformation unit, and integrating capacitor C3 is 0.1uF.

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