CN208156182U - A kind of multichannel directly measures formula mutual-inductor tester - Google Patents

A kind of multichannel directly measures formula mutual-inductor tester Download PDF

Info

Publication number
CN208156182U
CN208156182U CN201820525013.4U CN201820525013U CN208156182U CN 208156182 U CN208156182 U CN 208156182U CN 201820525013 U CN201820525013 U CN 201820525013U CN 208156182 U CN208156182 U CN 208156182U
Authority
CN
China
Prior art keywords
voltage
operational amplifier
divider resistance
circuit
control precision
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.)
Active
Application number
CN201820525013.4U
Other languages
Chinese (zh)
Inventor
顾红波
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NANJING DANDICK ELECTRIC INSTRUMENT Co Ltd
Original Assignee
NANJING DANDICK ELECTRIC INSTRUMENT Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NANJING DANDICK ELECTRIC INSTRUMENT Co Ltd filed Critical NANJING DANDICK ELECTRIC INSTRUMENT Co Ltd
Priority to CN201820525013.4U priority Critical patent/CN208156182U/en
Application granted granted Critical
Publication of CN208156182U publication Critical patent/CN208156182U/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The utility model discloses a kind of multichannels directly to measure formula mutual-inductor tester, including:DSP circuit,ARM circuit,Liquid crystal,Keyboard,Storage,RS232,Power supply,8 tunnels sample accurate voltage mutual inductor VT1~VT8,8 tunnels sample precision current transformer TA1~TA8,8 road sample resistance Rc,8 road voltage signal amplitude limiter circuits,No. 4 voltage transformers/sensor signal selective relay group J1~J16,No. 4 current transformers/sensor signal selective relay group J17~J24,16 tunnel voltage-programmed amplifying circuit V1~V8 and A1~A8,28 channel parallels sample 16 A/D circuits V_A/D and A_A/D,4 groups of range switching relays switch I/O expanded circuit V1_I/O,V2_I/O,A1_I/O and A2_I/O,All it is mounted in the Aluminum Alloy Chassis of a 4U standard.The up to 8 road test item error checkings of three-phase voltage+residual voltage and three-phase current+zero-sequence current may be implemented in the utility model;Measurement circuit is simple, without error of measurement test loop, only standard mutual inductor and the secondary output voltage of tested mutual inductor or current signal need to be accessed instrument.

Description

A kind of multichannel directly measures formula mutual-inductor tester
Technical field
The present invention relates to Electric Energy Metering Technology field, especially a kind of multichannel directly measures formula mutual-inductor tester.
Background technique
At present to the method for traditional voltage (electric current) transformer error calibrating mainly according to JJG313-2010《Measurement is used Current transformer》And JJG314-2010《Voltage transformer is used in measurement》,JJG1021-2007《Electric power mutual-inductor》Three calibrating rule Journey.Calibration method need using normal voltage (electric current) mutual inductor, mutual-inductor tester, voltage (electric current) mutual inductor load box with And boosting (up-flow) device.The core of test method is that normal voltage (electric current) mutual inductor connects with subject voltage (electric current) mutual inductor At error of measurement circuit, standard loop is measured together with difference circuit using mutual-inductor tester, tester finally shows tested electricity Press the ratio difference and differential seat angle of (electric current) mutual inductor.The calibration method is the authoritative scheme that measurement transformer is traced to the source.Highest can To be traceable to National primary standard.
The current transformer error measurement of the three-phase combination transformer of threephase current transformer composition, when test, according to surveying Amount point is respectively mutually pressed comparison method error of measurement route, is detected respectively by three-phase mutual-inductor tester to tested current transformer Injection Current Error amount out.When examining and determine Y connection three-phase combination transformer, the error measure route of current transformer couples three with V and is combined The measurement route of mutual inductor is identical.Y couples measurement three-phase combination voltage mutual inductor, gives tested voltage according to defined measurement point Mutual inductor applies voltage, each mutually to press comparison method error of measurement route, detects error amount respectively by three-phase mutual-inductor tester.Y connection Remaining winding/zero sequence voltage measuring transformer is given tested voltage transformer to apply voltage, is respectively mutually pressed according to defined measurement point Comparison method error of measurement route, detects error amount by mutual-inductor tester.Combination transformer (three-phase combined Instrument transformer) by threephase potential transformer and three single-phase (or two single-phase), current transformer combination is simultaneously Formed one for three-phase electrical power system metering, measuring mutual inductor.
Electronic type voltage transformer (sensor):It is that a kind of novel " three-phase voltage+residual voltage " measures one-piece type mutual inductance Device (sensor).Mutual inductor is generally 100V, 57.7V or 100/3V voltage using traditional electromagnetic induction principle manufacture, output; Sensor uses capacitance partial pressure technology, can be small analog quantity electricity with precise acquisition three-phase voltage and residual voltage, secondary output Pressure.
Electronic current mutual inductor (sensor):It is that " three-phase current+zero-sequence current " measures one-piece type sensor, it is secondary Output has traditional secondary current mode and secondary small analog voltage two ways.Electronic type voltage transformer (sensor) and electricity Type current transformer (sensor) is mainly used in one or two fusion devices of 10kV distribution, provides letter to measurement protection equipment Number.
Combination transformer can be using the single plane method of national verification regulation by mutually examining and determine.But electronic type voltage, electric current are mutual Sensor (sensor) then cannot achieve verification.Even there is existing three-phase mutual-inductor tester that can not also pass to electronic type at present Sensor verification.The class of accuracy of combination transformer and voltage current transformer (sensor) is generally:0.5 grade, 0.2 grade or electric current it is mutual Sensor (sensor) is 0.5S grades, 0.2S grades.
Due to the presence of the mutual inductor or sensor of three of the above mode, and class of accuracy is no more than 0.2 (0.2S) grade, Measurement can be achieved using the present invention.Using the direct method of measurement, by normal voltage (electric current) mutual inductor and measured voltage (electricity Stream) the synchronous A/D measurement of the secondary output voltage of mutual inductor/sensor (electric current), measurement obtains discrete shape data and is converted into floating Points obtain the fundamental voltage amplitude and phase difference of standard signal and measured signal, into one using floating type Fast Fourier Transform (FFT) Step can calculate the ratio difference and angular difference value of tested mutual inductor (sensor).
Summary of the invention
Technical problem to be solved by the present invention lies in provide a kind of multichannel and directly measure formula mutual-inductor tester, energy It enough solves the problems, such as the single-phase test of existing mutual-inductor tester, difference loop test need to be used and can only be examined and determine with no-load voltage ratio.
In order to solve the above technical problems, the present invention, which provides a kind of multichannel, directly measures formula mutual-inductor tester, including: DSP circuit, ARM circuit, liquid crystal, keyboard, storage, RS232, power supply, 8 tunnels sampling accurate voltage mutual inductor VT1~VT8,8 tunnels take Sample precision current transformer TA1~TA8,8 road sample resistance Rc, 8 road voltage signal amplitude limiter circuits, No. 4 voltage transformers/sensing Device signal selector relay group J1~J16, No. 4 current transformers/sensor signal selective relay group J17~J24,16 roads electricity Programmable amplifying circuit V1~V8 and A1~A8,28 channel parallels is pressed to sample 16 A/D circuit V_A/D and A_A/D, 4 groups of ranges Switch relay and switch I/O expanded circuit V1_I/O, V2_I/O, A1_I/O and A2_I/O, is all mounted on a 4U standard In Aluminum Alloy Chassis;DSP circuit respectively with ARM circuit, 16 tunnel voltage-programmed amplifying circuit V1~V8 and A1~A8,28 channels Parallel sampling 16 A/D circuits V_A/D and A_A/D, 4 groups of range switching relays switch I/O expanded circuit V1_I/O, V2_I/ O, A1_I/O is connected with A2_I/O;ARM circuit is connected with liquid crystal, storage, keyboard and RS232 respectively;8 tunnel voltage-programmeds are put Big circuit V1~V8 respectively with 8 road voltage signal amplitude limiter circuits, No. 4 voltage transformers/sensor signal selective relay group J1 ~J16,8 tunnels sampling accurate voltage mutual inductor VT1~VT8 are sequentially connected;8 tunnel voltage-programmed amplifying circuit A1~A8 are respectively with 4 Road current transformer/sensor signal selective relay group J17~J24,8 road sample resistances, 8 tunnels sample precision current transformer TA1~TA8 is sequentially connected.
Preferably, voltage-programmed amplifying circuit specifically includes:First operational amplifier, second operational amplifier, third fortune Calculate amplifier, four-operational amplifier, the first programme control precision divider resistance chip N1, the second programme control precision divider resistance chip N2 With third programme control precision divider resistance chip N3;The output end of first operational amplifier connects the first programme control precision divider resistance core 2 pins of piece N1, the inverting input terminal of the first operational amplifier are connected to the output end of the first operational amplifier and first program-controlled Between 2 pins of accurate divider resistance chip N1, the normal phase input end of the first operational amplifier connects KD;First programme control precision point The normal phase input end of the 6 pins connection second operational amplifier of piezoresistance chip N1, the first programme control precision divider resistance chip N1 8 pins connection second operational amplifier inverting input terminal, the output end of second operational amplifier connects the second programme control precision 4 pins of 2 pins of divider resistance chip N2, the first programme control precision divider resistance chip N1 are connected to second operational amplifier Between output end and 2 pins of the second programme control precision divider resistance chip N2;6 pipes of second programme control precision divider resistance chip N2 Foot connects the normal phase input end of third operational amplifier, the 8 pins connection third fortune of the second programme control precision divider resistance chip N2 The inverting input terminal of amplifier is calculated, the output end of third operational amplifier connects the 2 of third programme control precision divider resistance chip N3 Pin, 4 pins of the second programme control precision divider resistance chip N2 be connected to third operational amplifier output end and third it is program-controlled Between 2 pins of accurate divider resistance chip N3;6 pins of third programme control precision divider resistance chip N3 connect the 4th operation and put The reverse phase of the normal phase input end of big device, the 8 pins connection four-operational amplifier of third programme control precision divider resistance chip N3 is defeated Enter end, the output end of four-operational amplifier connects KDFA, and 4 pins of third programme control precision divider resistance chip N3 are connected to the Between the output end and KDFA of four-operational amplifier.
Preferably, 28 channel parallels, 16 A/D circuits of sampling are specially:A/D circuit digital part of interface:Wherein D0~ The bus of D15 and DSP connects, and the timer output pin of/COVST and DSP connect, and for starting A/D sampling ,/AD-END is connect The interruption input port of DSP makes DSP enter interrupt handling routine after sampling for A/D by middle fracture, and DSP enters interruption A/D measured value is read out after processing routine ,/CS-7606 is chip selection signal, and/RES_7606 is reset signal, and/RD is total Line reads signal, and+5VA2 is bus driver power supply;A/D breadboardin part of interface:CH1~CH8 is analog measurement input, AVCC is that simulation power supply interface, AGND, V1GND~V8GND are ground interfaces, defeated with two APL117.5V three-terminal voltage-stabilizing power supplys Power supply of two independent 5V as A/D chip out, wherein+5VA is simulation power supply all the way, another way+5VA2 is digital power system, AD780 fiducial chip is used to export 2.5V to A/D chip as reference voltage REF;Simulation ground AGND and digitally GND is in A/D core Piece bottom is shorted.
Beneficial effects of the present invention are:Three-phase voltage+residual voltage and three-phase current+zero-sequence current may be implemented up to 8 road test item error checkings;Normal voltage (electric current) mutual inductor can only be needed with subject voltage (electric current) mutual inductor difference no-load voltage ratio Result can be obtained using software conversion;The secondary output voltage of voltage (electric current) mutual inductor (electric current) is due to using precision transformer Isolation sampling, in the case where flashover occurs for extra-high voltage, EHV Potential Transformer error test, tester of the invention is not easy Damage;Measurement circuit is simple, only need to be by standard mutual inductor and the secondary output electricity of tested mutual inductor without error of measurement test loop Pressure or current signal access instrument of the invention.
Detailed description of the invention
Fig. 1 is tester structural schematic diagram of the invention.
Fig. 2 is that mutual-inductor tester of the invention verifies threephase potential transformer wiring diagram.
Fig. 3 is that mutual-inductor tester of the invention verifies three-phase voltage sensor wire figure.
Fig. 4 is that mutual-inductor tester of the invention verifies threephase current transformer wiring diagram.
Fig. 5 is that mutual-inductor tester of the invention verifies three-phase current sensor wiring diagram.
Fig. 6 is that mutual-inductor tester of the invention verifies three-phase zero sequence current mutual inductor wiring diagram.
Fig. 7 is that mutual-inductor tester of the invention verifies three-phase zero sequence current sensor wiring diagram.
Fig. 8 is that mutual-inductor tester of the invention verifies programmable amplifying circuit schematic illustration.
Fig. 9 is A/D circuit theory schematic diagram of the invention.
Specific embodiment
As shown in Figure 1, a kind of multichannel directly measures formula mutual-inductor tester, including:DSP circuit, ARM circuit, liquid crystal, Keyboard, storage, RS232, power supply, 8 tunnels sampling accurate voltage mutual inductor VT1~VT8,8 tunnels sampling precision current transformer TA1~ TA8,8 road sample resistance Rc, 8 road voltage signal amplitude limiter circuits, No. 4 voltage transformers/sensor signal selective relay group J1 ~J16, No. 4 current transformers/sensor signal selective relay group J17~J24,16 tunnel voltage-programmed amplifying circuit V1~V8 16 A/D circuits V_A/D and A_A/D, 4 groups of range switching relay switching I/O extensions are sampled with A1~A8,28 channel parallels Circuit V1_I/O, V2_I/O, A1_I/O and A2_I/O are all mounted in the Aluminum Alloy Chassis of a 4U standard;DSP circuit point 16 A/D circuit V_ are not sampled with ARM circuit, 16 tunnel voltage-programmed amplifying circuit V1~V8 and A1~A8,28 channel parallels A/D is connected with A_A/D, 4 groups of range switching relay switchings I/O expanded circuit V1_I/O, V2_I/O, A1_I/O with A2_I/O It connects;ARM circuit is connected with liquid crystal, storage, keyboard and RS232 respectively;8 tunnel voltage-programmed amplifying circuit V1~V8 are respectively with 8 Road voltage signal amplitude limiter circuit, No. 4 voltage transformers/sensor signal selective relay group J1~J16, the accurate electricity of 8 tunnels sampling Pressure mutual inductor VT1~VT8 is sequentially connected;8 tunnel voltage-programmed amplifying circuit A1~A8 respectively with No. 4 current transformers/sensor Signal selector relay group J17~J24,8 road sample resistances, 8 tunnels sampling precision current transformer TA1~TA8 are sequentially connected.
As shown in Figures 2 and 3, using A phase voltage mutual inductor (sensor) as example explanation:
The secondary winding output access A phase a and x voltage wiring terminal of standard potential transformer;Measured voltage mutual inductor (passes Sensor) secondary output access A phase 1a and 1n connecting terminal;A and x voltage wiring terminal and sampling VT1 input connect, VT1 bis- Secondary output accesses programmable amplifying circuit (V1);1a and 1n connecting terminal can select to input using sampling VT2 by relay Still it is directly inputted into amplitude limiter circuit and programmable amplifying circuit (V2).
Selection foundation be:Tested is conventional voltage transformer secondary output then using the normally closed point access sampling of relay The output of VT2, VT2 pass through the normally closed point access amplitude limiter circuit of relay and programmable amplifying circuit (V2);If tested is voltage sensor Device, sensor output are small voltage signal, therefore make V1_I/O output control signal by program, make J1, J2, J3 and J4 relay Device opened point closure, sensor export small signal access amplitude limiter circuit programmable amplifying circuit (V2).
DSP gives V_A/D converter sampling enabling signal by timer internal, and the frequency of enabling signal is 50Hz × 512 =25.6kHz, 512 times of corresponding measured voltage mutual inductor power frequency, so that available to 512 of each cycle of measured signal is Even test A/D data.DSP reads 8 groups of V_A/D shape datas by parallel bus, and every group of V_A/D shape data is 512 It is a.DSP is by this 8 groups of V_A/D shape datas by rate conversion at the voltage value of floating type.DSP will be according to the voltage of 8 groups of floating types 8 voltage effective values are calculated using real available value program in value, and DSP judges automatically the amplification of current automatic range switching circuit Whether multiple suitable, and suitable range is switched to if improper, the voltage effective value made V_A/D range 30%~ 64%, the peak value of corresponding signal-under-test is within the 90% of V_A/D range.A phase voltage mutual inductor (sensor) automatic range The control signal of switching and relay switching is provided by V1_I/O.
The A phase standard potential transformer floating type voltage array (512) and measured voltage mutual inductance that DSP obtains measurement Device (sensor) floating type voltage array (512) is calculated by fast fourier transform algorithm, obtains two groups of voltage fundamentals Virtual value and phase difference, it is then mutual by the no-load voltage ratio of standard potential transformer, the no-load voltage ratio of measured voltage mutual inductor, sampling voltage The no-load voltage ratio of sensor and the multiplying power of two-way programmable amplifying circuit are converted into ratio difference and the angle of measured voltage mutual inductor (sensor) Difference.
B phase, C phase and zero sequential potential transformer (sensor) workflow are referring to A phase measurement procedure.V1_I/O is simultaneously B phase voltage mutual inductor (sensor) range switching signal and relay switching signal are provided.V2_I/O provides C phase, zero sequence electricity Press mutual inductor (sensor) range switching signal and relay switching signal.
As shown in Figure 4 and Figure 5, using A phase current mutual inductor (sensor) as example explanation:
The secondary winding output access A phase k1 and k2 current wiring terminal of standard current transformer;K1 and k2 electric current wiring Terminal and sampling precision current transformer TA1 input connect, and generate and take after the accurate sample resistance Rc of bis- output of TA1 access one Sample voltage accesses to programmable amplifying circuit (A1).
Using A phase current mutual inductor as example explanation:
S1 the and s2 current wiring terminal of the secondary output access A phase TA of tested current transformer;A phase is tested Current Mutual Inductance S1 the and s2 current wiring terminal of device access accesses an accurate sampled current transformer TA2;Bis- output of TA2 accesses another Sampling voltage is generated after accurate sample resistance Rc to access to amplitude limiter circuit by the normally-closed contact of J17, J18 relay and program-controlled put Big circuit (A2).
Using A phase current sensor as example explanation:
S3 the and s4 voltage wiring terminal of the secondary output access A phase of tested current sensor;A phase S3 and s4 voltage wiring terminal voltage accesses to amplitude limiter circuit after the normally opened contact of J17, J18 relay closure and program-controlled puts Big circuit (A2);Programmable amplifying circuit (V2) input signal selection foundation be:Tested is conventional Current Transformer Secondary The output that output is directly accessed sampling TA2, TA2 accesses amplitude limiter circuit and programmable amplifying circuit by relay normally closed contact (A2);If tested is current sensor, sensor output is small voltage signal, therefore makes A1_I/O output control letter by program Number, it is closed J17 and J18 relay normally open contact, sensor exports small signal access amplitude limiter circuit programmable amplifying circuit (A2). The control signal of automatic range switching is provided by A1_I/O.
DSP gives B_A/D converter sampling enabling signal by timer internal, and the frequency of enabling signal is 50Hz × 512 =25.6kHz, 512 times of corresponding measured voltage mutual inductor power frequency, so that available to 512 of each cycle of measured signal is Even test A/D data.DSP reads 8 groups of B_A/D shape datas by parallel bus, and every group of B_A/D shape data is 512 It is a.DSP is by this 8 groups of B_A/D shape datas by rate conversion at the voltage value of floating type.DSP will be according to the voltage of 8 groups of floating types 8 voltage effective values are calculated using real available value program in value, and DSP judges automatically the amplification of current automatic range switching circuit Whether multiple suitable, and suitable range is switched to if improper, the voltage effective value made A/D range 30%~ 64%, the peak value of corresponding signal-under-test is within the 90% of B_A/D range.
As shown in Figure 6 and Figure 7, the A phase standard current transformer floating type electric current array (512) that DSP obtains measurement And tested current transformer (sensor) floating type electric current array (512) is calculated by fast fourier transform algorithm, is obtained To the virtual value and phase difference of two groups of current first harmonics, then pass through the no-load voltage ratio of standard current transformer, tested current transformer It is mutual that the multiplying power of the no-load voltage ratio of (sensor), the no-load voltage ratio of sampled current transformer and two-way programmable amplifying circuit is converted into tested electric current The ratio error and angular error of sensor (sensor).
B phase, C phase and zero sequence current mutual inductor (sensor) workflow are surveyed referring to A phase current mutual inductor (sensor) Measure process.A1_I/O also provides B phase current mutual inductor (sensor) range switching signal and relay switching signal simultaneously. A2_I/O provides C phase, zero sequence current mutual inductor (sensor) range switching signal and relay switching signal.
Standard mutual inductor secondary singal I and tested mutual inductor (sensor) secondary singal I' passes through mathematics model analysis such as Under:
The secondary singal of standard mutual inductor and tested mutual inductor (sensor) is obtained by A/D measurement, each period is equal This two groups of 512 measurement data are converted into floating number, and substitute into Fast Fourier Transform (FFT) by 512 discrete signal values of even acquisition The expression formula 1 and formula 2 of standard mutual inductor and tested mutual inductor (sensor) two groups of signals is calculated in algorithm (FFT).Expression Signal amplitude value and initial phase in formula containing fundametal compoment and each harmonic component.
By taking current transformer is tested calibration as an example:Two groups of secondary currents of standard current transformer and tested current transformer The two groups of time-domain expressions that obtain after signal Fourier transformation are:
Wherein:I (t) is standard current transformer secondary current signal, i'(t) it is that standard current transformer secondary current is believed Number, InAnd I'nFor each harmonic virtual value size,WithFor the starting phase angle of each harmonic.
Tester passes through software for the secondary base of the secondary fundamental signal of standard current transformer and tested current transformer Wave signal obtains the ratio difference of tested current transformer by formula (3);The phase of tested current transformer is obtained by formula (4) Angular difference;
Wherein:K1For the electric current ratio for being tested current transformer, K0For the electric current ratio of standard current transformer;I0For standard electric Current transformer fundamental wave virtual value, I'0To be tested current transformer fundamental wave virtual value;For standard current transformer fundamental wave initial phase Position,To be tested current transformer fundamental wave initial phase;f50HzIt is tested current transformer fundamental wave than difference, δ50HzFor tested electricity Current transformer fundamental wave angular difference value.
It is measured as current sensor or is measured as voltage transformer (sensor) to be also using formula (1~4) identical meter Calculation method, only definition has difference.
Amplitude limiter circuit is input to power supply using a clipping resistance (present invention is using 20k Ω, 1W) and 2 diodes Power supply Vdd (+12V) and Vss (- 12V).When external input signal is more than ± 12.6V, diode current flow, by programming amplifying electricity The input voltage on road is clamped down between ± 12.6V, will not amplifying circuit to rear class and A/D cause excessive pressure damages.Clipping resistance 150V voltage can be born for a long time, it well will be due to the software setting damage caused to equipment circuit different with practical access signal It is bad.If instrument is in off-mode, Vdd and Vss are 0V, and can bear 140V voltage for a long time at this time will not be to circuit and element Damage.A2_I/O provides C phase, zero sequence current mutual inductor (sensor) range switching signal and relay switching signal.Two The data of A/D converter are read by simultaneously data/address bus by DSP.
It uses ARM to realize human-computer interaction for core processor, liquid crystal display, display related interfaces sum number can be driven According to, the dependent instruction of calibration personnel can be inputted by keyboard, can also be by serial ports and computer communication, realization is by computer The automatic measurement data for obtaining calibrating installation, can also carry out data management.ARM is that the human-computer interaction module of core processor will The basic parameter of the input of calibration personnel issues data processing module DSP.
Data processing module is designed by the processor of DSP core, is the key that device observing and controlling component.Data processing module needs Program will be carried out according to setup parameter in human-computer interaction module ARM to be calculated than difference and angular difference value.Data processing module Final survey calculation result is sent to human-computer interaction core ARM, ARM the results are shown on liquid crystal or be stored in by DSP On reservoir.
ARM framework is used in device, Peripheral Interface is abundant.Processing speed reaches 66MHz, facilitates the system for reducing application Grade cost.Sufficiently meet this system design requirement.A/D converter used in device uses high-speed parallel successive approximation A/ D conversion circuit is that high integration, 8 channel parallel high-speed synchronous are adopted using 16 A/D acquisition chip AD7606 of ADI company Sample, 16bit Approach by inchmeal (SAR) type ADC.
As shown in figure 9, for wherein A/D circuit diagram, two-way A/D schematic diagram are identical all the way.
A/D circuit digital part of interface:The wherein bus connection of D0~D15 and DSP;The timer of/COVST and DSP is defeated Pin connects out, for starting A/D sampling;/ AD-END connects the interruption input port of DSP, passes through interruption after sampling for A/D Mouth makes DSP enter interrupt handling routine, and DSP reads out A/D measured value after entering interrupt handling routine;/ CS-7606 is piece Select signal;/ RES_7606 is reset signal;/ RD is that bus reads signal;+ 5VA2 is bus driver power supply;
A/D breadboardin part of interface:CH1~CH8 is analog measurement input;AVCC be simulation power supply interface, AGND, V1GND~V8GND is ground interface;Two APL117.5V three-terminal voltage-stabilizing power supplys are used to export two independent 5V as A/D chip Power supply, wherein all the way+5VA be simulation power supply, another way+5VA2 is digital power system;With AD780 fiducial chip export 2.5V to A/D chip is as reference voltage REF.
Simulation ground AGND and digitally GND is shorted in A/D chip bottom.
There is two-way 5V, two groups of ± 12V power supplys using power module in device, each other equal electrical isolation.5V all the way Power supply is powered to DSP and ARM, and 5V power supply is powered to I/O expanded circuit all the way.Wherein one group of ± 12V power supply is to current transformer (sensor) programmable amplifying circuit and current channel A_A/D power supply, another group of ± 12V power supply give voltage transformer (sensor) journey Control amplifying circuit and voltage channel U_A/D power supply.
As shown in figure 8, programmable amplifying circuit is amplified using programme control precision divider resistance chip MAX5431 and high performance computation Device OP2177 is realized.MAX5431 uses 2 digital signal lines that can select 1 road divider resistance coefficient with 4, realizes 1,2,4,8 with amplifier Enlargement ratio.Gain accuracy is 0.025%.The programmable amplifying circuit of each measurement object uses three groups of amplifying circuits, Realize 1,2,4,8,16,32,64,128,256,512 enlargement ratios, the verification demand for meeting S grades of current transformers (needs The error of 1% operating current point test current transformer).
Voltage-programmed amplifying circuit specifically includes:First operational amplifier, second operational amplifier, third operation amplifier Device, four-operational amplifier, the first programme control precision divider resistance chip N1, the second programme control precision divider resistance chip N2 and third Programme control precision divider resistance chip N3;The output end of first operational amplifier connects the first programme control precision divider resistance chip N1's 2 pins, the inverting input terminal of the first operational amplifier are connected to the output end and the first programme control precision point of the first operational amplifier Between 2 pins of piezoresistance chip N1, the normal phase input end of the first operational amplifier connects KD;First programme control precision divider resistance The normal phase input end of the 6 pins connection second operational amplifier of chip N1,8 pins of the first programme control precision divider resistance chip N1 The inverting input terminal of second operational amplifier is connected, the output end of second operational amplifier connects the second programme control precision divider resistance 2 pins of chip N2,4 pins of the first programme control precision divider resistance chip N1 be connected to the output end of second operational amplifier with Between 2 pins of second programme control precision divider resistance chip N2;The 6 pins connection the of second programme control precision divider resistance chip N2 8 pins of the normal phase input end of three operational amplifiers, the second programme control precision divider resistance chip N2 connect third operational amplifier Inverting input terminal, third operational amplifier output end connection third programme control precision divider resistance chip N3 2 pins, second 4 pins of programme control precision divider resistance chip N2 are connected to the output end and third programme control precision partial pressure electricity of third operational amplifier Between 2 pins for hindering chip N3;The positive of the 6 pins connection four-operational amplifier of third programme control precision divider resistance chip N3 Input terminal, the inverting input terminal of the 8 pins connection four-operational amplifier of third programme control precision divider resistance chip N3, the 4th fortune The output end for calculating amplifier connects KDFA, and 4 pins of third programme control precision divider resistance chip N3 are connected to the 4th operation amplifier Between the output end and KDFA of device.
The present invention tests without error of measurement test circuit, and wiring is simple.Single-phase voltage (electric current) mutual inductor can be verified. Verification while three-phase voltage+threephase current transformer in combination transformer may be implemented, be more in line with the reality of combination transformer Border working condition.Three-phase+zero sequential potential transformer verification that one or two fusions use in distribution may be implemented, also may be implemented Three-phase current+zero sequence current mutual inductor verification.Three-phase+residual voltage sensor that one or two fusions use in distribution may be implemented Verification, the verification of three-phase current+zero sequence current sensor also may be implemented.
The present invention uses the direct method of measurement, used sampling precision current (voltage) mutual inductor, sampling precision resistance And measuring circuit is high precision grade high stability device or circuit, stable testing is reliable, can achieve 0.05 grade of voltage, electricity 0.05S grades of stream.Meet the verification of 0.2 grade of (0.2S) following voltage (electric current) mutual inductor (sensor).It is embedding using the direct method of measurement Angular difference value can be directly obtained by entering formula software, accepted standard voltage (electric current) mutual inductor can with test item different voltages ratio or Calculating and display than difference can be realized by no-load voltage ratio conversion in electric current ratio.
Extension function 1 of the invention voltage channel can will be inputted as standard potential transformer all the way, other 7 tunnels are all It is inputted as measured voltage mutual inductor, may be implemented using 1 standard potential transformer at most that 7 measured voltages of verification are mutual simultaneously The error of sensor or winding.Function 2 is extended, voltage channel can will be inputted all the way as standard potential transformer, the small signal in 4 tunnels Channel is directly inputted all as tested electronic voltage transducer input, may be implemented most using 1 standard potential transformer The error of 4 measured voltage sensors is verified simultaneously.Function 3 is extended, can will be made in precision current transformer sampling channel all the way For standard current transformer input, other 7 tunnels all as tested current transformer input, be may be implemented using 1 normalized current Mutual inductor at most verifies the error of 7 tested current transformers simultaneously.Function 4 is extended, it can will precision current transformer all the way It samples channel to input as standard current transformer, the small signal in 4 tunnels directly inputs channel all as tested electronic current sensing The at most error of 4 tested current sensors of verification simultaneously may be implemented using 1 standard current transformer in device input.

Claims (3)

1. a kind of multichannel directly measures formula mutual-inductor tester, which is characterized in that including:DSP circuit, ARM circuit, liquid crystal, Keyboard, storage, RS232, power supply, 8 tunnels sampling accurate voltage mutual inductor VT1~VT8,8 tunnels sampling precision current transformer TA1~ TA8,8 road sample resistance Rc, 8 road voltage signal amplitude limiter circuits, No. 4 voltage transformers/sensor signal selective relay group J1 ~J16, No. 4 current transformers/sensor signal selective relay group J17~J24,16 tunnel voltage-programmed amplifying circuit V1~V8 16 A/D circuits V_A/D and A_A/D, 4 groups of range switching relay switching I/O extensions are sampled with A1~A8,28 channel parallels Circuit V1_I/O, V2_I/O, A1_I/O and A2_I/O are all mounted in the Aluminum Alloy Chassis of a 4U standard;DSP circuit point 16 A/D circuit V_ are not sampled with ARM circuit, 16 tunnel voltage-programmed amplifying circuit V1~V8 and A1~A8,28 channel parallels A/D is connected with A_A/D, 4 groups of range switching relay switchings I/O expanded circuit V1_I/O, V2_I/O, A1_I/O with A2_I/O It connects;ARM circuit is connected with liquid crystal, storage, keyboard and RS232 respectively;8 tunnel voltage-programmed amplifying circuit V1~V8 are respectively with 8 Road voltage signal amplitude limiter circuit, No. 4 voltage transformers/sensor signal selective relay group J1~J16, the accurate electricity of 8 tunnels sampling Pressure mutual inductor VT1~VT8 is sequentially connected;8 tunnel voltage-programmed amplifying circuit A1~A8 respectively with No. 4 current transformers/sensor Signal selector relay group J17~J24,8 road sample resistances, 8 tunnels sampling precision current transformer TA1~TA8 are sequentially connected.
2. multichannel as described in claim 1 directly measures formula mutual-inductor tester, which is characterized in that voltage-programmed amplification electricity Road specifically includes:First operational amplifier, second operational amplifier, third operational amplifier, four-operational amplifier, the first journey Control accurate divider resistance chip N1, the second programme control precision divider resistance chip N2 and third programme control precision divider resistance chip N3; The output end of first operational amplifier connects 2 pins of the first programme control precision divider resistance chip N1, the first operational amplifier Inverting input terminal be connected to the first operational amplifier output end and the first programme control precision divider resistance chip N1 2 pins it Between, the normal phase input end of the first operational amplifier connects KD;The 6 pins connection second of first programme control precision divider resistance chip N1 The normal phase input end of operational amplifier, the 8 pins connection second operational amplifier of the first programme control precision divider resistance chip N1 Inverting input terminal, the output end of second operational amplifier connect 2 pins of the second programme control precision divider resistance chip N2, the first journey 4 pins for controlling accurate divider resistance chip N1 are connected to the output end and the second programme control precision divider resistance of second operational amplifier Between 2 pins of chip N2;The positive of the 6 pins connection third operational amplifier of second programme control precision divider resistance chip N2 is defeated Enter end, the inverting input terminal of the 8 pins connection third operational amplifier of the second programme control precision divider resistance chip N2, third operation 2 pins of the output end connection third programme control precision divider resistance chip N3 of amplifier, the second programme control precision divider resistance chip 4 pins of N2 are connected between the output end of third operational amplifier and 2 pins of third programme control precision divider resistance chip N3; The normal phase input end of the 6 pins connection four-operational amplifier of third programme control precision divider resistance chip N3, third programme control precision The inverting input terminal of the 8 pins connection four-operational amplifier of divider resistance chip N3, the output end of four-operational amplifier connect Meet KDFA, 4 pins of third programme control precision divider resistance chip N3 be connected to four-operational amplifier output end and KDFA it Between.
3. multichannel as described in claim 1 directly measures formula mutual-inductor tester, which is characterized in that 28 channel parallels are adopted 16 A/D circuits of sample are specially:A/D circuit digital part of interface:Wherein D0~D15 and DSP bus connection ,/COVST with The timer output pin of DSP connects, and for starting A/D sampling ,/AD-END connects the interruption input port of DSP, samples for A/D After so that DSP is entered interrupt handling routine by middle fracture, DSP reads out A/D measured value after entering interrupt handling routine Come ,/CS-7606 is chip selection signal, and/RES_7606 is reset signal, and/RD is that bus reads signal, and+5VA2 is bus driver electricity Source;A/D breadboardin part of interface:CH1~CH8 is analog measurement input, and AVCC is simulation power supply interface, AGND, V1GND ~V8GND is ground interface, and two APL117.5V three-terminal voltage-stabilizing power supplys is used to export the confession of two independent 5V as A/D chip Electricity, wherein+5VA is simulation power supply all the way, another way+5VA2 is digital power system, exports 2.5V to A/D with AD780 fiducial chip Chip is as reference voltage REF;Simulation ground AGND and digitally GND is shorted in A/D chip bottom.
CN201820525013.4U 2018-04-13 2018-04-13 A kind of multichannel directly measures formula mutual-inductor tester Active CN208156182U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201820525013.4U CN208156182U (en) 2018-04-13 2018-04-13 A kind of multichannel directly measures formula mutual-inductor tester

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201820525013.4U CN208156182U (en) 2018-04-13 2018-04-13 A kind of multichannel directly measures formula mutual-inductor tester

Publications (1)

Publication Number Publication Date
CN208156182U true CN208156182U (en) 2018-11-27

Family

ID=64379075

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201820525013.4U Active CN208156182U (en) 2018-04-13 2018-04-13 A kind of multichannel directly measures formula mutual-inductor tester

Country Status (1)

Country Link
CN (1) CN208156182U (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108414960A (en) * 2018-04-13 2018-08-17 南京丹迪克电力仪表有限公司 A kind of multichannel directly measures formula mutual-inductor tester and method of calibration
CN109521268A (en) * 2018-12-28 2019-03-26 珠海格力电器股份有限公司 Electric energy metering device, ammeter equipment and configuration method
CN109946508A (en) * 2019-04-04 2019-06-28 乳源东阳光机械有限公司 A kind of portable type current detection recording device
CN111474430A (en) * 2020-04-20 2020-07-31 广东电网有限责任公司 Excitation characteristic testing device of voltage transformer
CN111487576A (en) * 2020-04-30 2020-08-04 浙江省方正校准有限公司 Miniature current transformer measuring device based on direct measurement method
CN111693925A (en) * 2020-07-20 2020-09-22 内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司 Current transformer detection operation platform and multi-position top-speed current transformer calibration system
CN112859661A (en) * 2019-11-28 2021-05-28 北京龙坤盛达科技有限公司 Eight-channel synchronous control technology

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108414960A (en) * 2018-04-13 2018-08-17 南京丹迪克电力仪表有限公司 A kind of multichannel directly measures formula mutual-inductor tester and method of calibration
CN109521268A (en) * 2018-12-28 2019-03-26 珠海格力电器股份有限公司 Electric energy metering device, ammeter equipment and configuration method
CN109946508A (en) * 2019-04-04 2019-06-28 乳源东阳光机械有限公司 A kind of portable type current detection recording device
CN112859661A (en) * 2019-11-28 2021-05-28 北京龙坤盛达科技有限公司 Eight-channel synchronous control technology
CN111474430A (en) * 2020-04-20 2020-07-31 广东电网有限责任公司 Excitation characteristic testing device of voltage transformer
CN111487576A (en) * 2020-04-30 2020-08-04 浙江省方正校准有限公司 Miniature current transformer measuring device based on direct measurement method
CN111487576B (en) * 2020-04-30 2022-12-30 浙江省计量科学研究院 Miniature current transformer measuring device based on direct measurement method
CN111693925A (en) * 2020-07-20 2020-09-22 内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司 Current transformer detection operation platform and multi-position top-speed current transformer calibration system
CN111693925B (en) * 2020-07-20 2023-01-03 内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司 Current transformer detection operation platform and multi-position top-speed current transformer calibration system

Similar Documents

Publication Publication Date Title
CN208156182U (en) A kind of multichannel directly measures formula mutual-inductor tester
CN108414960A (en) A kind of multichannel directly measures formula mutual-inductor tester and method of calibration
CN100520437C (en) Integrated detecting and measuring method for metering property of high voltage power meter
CN201654130U (en) Automatic measuring and calibrating device of high-impedance measuring apparatus
CN108279396A (en) Anti- DC component current transformer error tester and its test method
Cataliotti et al. A new measurement method for the detection of harmonic sources in power systems based on the approach of the IEEE Std. 1459–2000
CN208818818U (en) A kind of low-power consumption program control type current mutual inductor field detecting device
CN108761375A (en) A kind of low-power consumption program control type current mutual inductor field detecting device
CN206292307U (en) A kind of device of utilization Wheatstone bridge measuring resistance
CN106483397B (en) A kind of electric energy quality detection device and measurement method of high-precision high bandwidth
CN109444783A (en) A kind of one or two fusion device sampling precision test methods of power distribution network
CN104931914A (en) Analog field high voltage energy meter calibration system
CN106443561A (en) Overall inspection method and apparatus for electric energy metering devices of 35kV or below
CN106646334A (en) Method and system for calculating metering error of electric energy meter
CN101950009A (en) Three-phase intelligent transformer calibrator
CN201852886U (en) Multifunctional earth resistance tester
CN202649455U (en) Embedded accuracy tester for current transformer
CN105699781B (en) A kind of transformer leakage inductance and Measuring DC Resistance
CN102081150B (en) 'Virtual complex impedance method'-based power frequency line parameter tester calibration device and method
CN206557369U (en) High-voltage electric-energy meter on-line monitoring system based on carrier communication
CN202939297U (en) Verification system for ground resistance tester
CN202330557U (en) Automatic calibration device of mutual inductor load box
CN204631238U (en) A kind of large direct current measuring device ripple response performance test macro
CN104820199B (en) Large direct current measuring device ripple response performance test system and method
CN108089058A (en) A kind of discrimination method of the positive order parameter of robust distribution network line

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant