CN1016820B - Portable micro-computer controlled multifuncitonal tester of protective relay - Google Patents

Abstract

The present invention provides an instrument of a triphase current source and a voltage source with adjustable frequencies, phases and amplitude values, which can superimpose ultraharmonics on fundamental waves. The instrument can replace a traditional testing loop which is composed of a transformer, a phase shifter, a current booster and various meters. The instrument has the testing functions of frequencies, phases and time. Because the instrument is programmable, corresponding program can be input to test various relays, record and print the parameters of voltage, resistance, time, etc. of working current, and paint characteristic curves.

Description

Portable micro-computer controlled multifuncitonal tester of protective relay

The invention belongs to the testing tool of electric power emergency protective circuit device.

Recent decades, the electric system of China all adopts by three phase worker power and powers.Through transformer, phase shifter, strong current generator, slide wire resistance is to produce three-phase voltage and the electric current that amplitude and phase place can change arbitrarily, with debugging relay protection and other aut.eq..Also need with accurate equipment such as voltage table, reometer, phasometer, frequency meter and millisecond meter in order to measure each physical quantity.These things transportation difficulty, to take on-the-spot area big, must manually read and record data last manual list and drawing during debugging by part.Since backward in technique, often need just can mix up complicated protective device, so relevant workman and technician require to improve this state urgently with 1 to 2 week.

The seventies, relay factory, First Machinery Industry Department Acheng and Xuchang circuit breaker factory have produced protective device testing table (list of references 1) in succession, and Anshan Power Administration and Ningxia power administration have also developed the protective device testing table respectively.These equipment are than traditional improvement in various degree that had, but adopt traditional technology, have shortcomings such as automaticity difference function is not strong.

Early eighties, China has built Gezhou Dam-tafelberg, many 500,000 volts of extra high voltage networks such as Datong District-Beijing and northeast, East China.Because the technical requirement in debugging of these relay protection of transmission line is higher, so introduce more advanced adjusting instrument (list of references 2.3) from the West Germany and the U.S..

The device that West Germany Siemens Company produces still adopts traditional technology basically, has set up electronic control circuit, can do dynamically test, promptly simulates from normal condition to forward malfunction, transient fault to, coincide with permanent fault etc.The tester that U.S. Doble Engineering Campany produces adopts the electronic simulation technology, and by the oscillation frequency device, formations such as amplifier feed single phase poaer supply and can obtain a power frequency three-phase voltage and a phase current.Their phase place and amplitude all can be adjusted arbitrarily.In order to do dynamic test, also need to increase other device.These two kinds of testers are more convenient than traditional method in the use, are subjected to very much field worker and technician's welcome.Their shortcoming is that automaticity is high not enough, and data of every survey are all wanted manual intervention, more do not have automatic record, tabulation and drawing function, can not produce harmonic wave and physical quantitys such as survey frequency, phase place.

Because electrified locomotive and by thyristor sharply increasing and the construction of DC transmission system to the load of electric furnace, electrolysis installation power supply; in power system voltage and the electric current component of higher hamonic wave greatly to influence the normal operation of relay protection and other aut.eq. degree (document 4.5) in order to test this problem, Ministry of Water Resources and Power Industry's Nanjing Automation Research Institute has been developed comprehensive humorous wave generating device (list of references 6) and micro-processor controlled relay debugging device (list of references 7).The former forms with electronic circuits such as phase-locked, frequency multiplication, filtering and phase shifts.More complicated, function singleness.The latter can produce a three-phase main-frequency voltage and a phase current, can survey the starting value and the actuation time of relay.These two kinds of devices are owing to some technical reason, also do not reach at present can practical application degree.

Over year, abroad aspect the relay protection test robotization, do a lot surplus in the of nearly ten.(list of references 8) utilizes multi-purpose computer to produce the light current simulating signal, goes the performance of development test middle distance relay DC loop.This way is both economical, but can not test the power-frequency voltage and the current return of protection, can not debug on-the-spot protection with it.(list of references 9) introduced digital technology, but is not computing machine, can periodically test electric current, voltage and the frequency relay of genset automatically.In order to use contactless way, produce numerical value variable current or voltage, it constitutes so-called resting potential device with 8 resistances of 8 bidirectional triode thyristor pipes switchings by the resistance of binary combination.It seems that this way was both heavy two complicated today, and can not measuring distance, complicated relay such as differential.(list of references 10) writes down the test findings of three relays simultaneously with a computing machine, compare with preceding once result, judge good and bad, make in performance plot, the test, it will cooperate the multi-path digital instrument of three relay test devices and band instantaneous set function to use, and seems very complicated and can not pointwise test automatically.(list of references 11) is the higher power transmission and distribution protection tester of seeing at present of automaticity.It can produce a three-phase voltage and a phase current by computer control, and the phase place of electric current and voltage, amplitude and frequency can change, in order to debugging frequency relay and impedance relay.If the increase annex, it can also produce three-phase current.This equipment can not produce higher hamonic wave, does not also have the function of survey frequency and phase place, for print record data and the characteristic of drawing impedance relay, also needs external printer and X-Y recorder, is not easy to on-the-spot the use.

By online information retrieval U.S. Dialog system World Patenfs Index 1963-1987, the result shows there be not the patent documentation identical with the present invention.

The object of the present invention is to provide a kind of multifunctional relay protection tester of portable microcomputer control.Multi-functional is outstanding advantage of the present invention, and it not only can produce the first-harmonic of three-phase voltage and three-phase current, can also produce higher hamonic wave.Simultaneously it can also Measuring Time and frequency and two electric weight between phase place.This has given full play to outside the length of computing machine, and when load changed within the specific limits, the amplitude of output three-phase current and voltage was compared with setting valve, and error is in allowed band, and each setting valve all can be by reading on the display monitor central monitoring system screen.So when test be attached reometer, voltage table and phasometer in addition.On line when this point had not only been saved equipment and test but be convenient to each power test and each transformer station between frequent transportation.The automaticity height is another advantage of the present invention.Because this tester is programmable, so after importing corresponding program, just can automatically test, write down and print various parameters automatically, as action current, voltage to various relays, resistance value and actuation time etc., draw the family curve of relay at last.

Accompanying drawing of the present invention is:

Fig. 1: tester block diagram.

Fig. 2: current source amplifier and voltage amplifier schematic diagram.

Fig. 3: the wiring diagram of current source amplifier and voltage amplifier.

Fig. 4: survey frequency, phase place and time three kinds of physical quantity block diagrams.

Fig. 5: frequency, phase place and time measurement circuit wiring diagram and audible alarm loop.

Task of the present invention realizes that with block diagram shown in Figure 1 among the figure, microcomputer is the core component of whole instrument. Its effect is the current program of just carrying out of storage, and central processing unit calculates and control the task that other parts are finished regulation step by step according to instruction. Magnetic tape station or disc unit are the mechanisms of forever storing program or data, and keyboard is that to accept people's instruction be interface to computer. By keyboard, can call in internal memory and bring into operation from the program that disk or magnetic tape station will be finished in advance, use then " menu " mode to select the function that will finish and import various setting valves, allow computer automatically go to carry out the task of appointment. By keyboard, can also import and debug new program, to be confirmed its correct after, again it is deposited in disk or the tape, in order to using from now on. Display also is interactive interface, from display screen, can see the result of order, program, definite value and the machine execution of input, and computed full-screen editing function can conveniently be revised original program. Program and test result that printer plotter is being developed or prepared to carry out in can print memory also can be come out test result with curve or diagrammatic representation, be convenient to people and analyze.

The effect of 6 digital-to-analog conversions (D/A) chip is that the computing machine calculated in advance is good and exist the three-phase current in the internal memory and the digital quantity of three-phase voltage to convert corresponding analog quantity to, flow to three voltage amplifiers and three current source amplifiers then respectively, to produce bigger three-phase voltage and the three-phase current of power that conforms to setting valve, the effect of address decoder is to convert the interface IP address that CPU sends here to control signal, open the data channel of respective chip, read in data that data bus sends here or data are delivered to CPU by bus.

The effect of amplification and rectification circuit and two block counts/timing chip is a function of finishing survey frequency, phase place and time.

Introduce the formation of each several part of the present invention below

1 main frame

The CPU of main frame adopts the Z80A chip.Its clock is 3.57954 megahertzes.In the read-only memory (ROM) of 16K, solidified the BASIC interpretive routine.PEEK wherein, POPK, OUT, statements such as TNP and USR make user read/write memory and input/output interface easily, in some occasion that requires to input or output fast data, can also call the program that machine code is write.This point is that the present invention can realize one of multi-functional key, and this instrument and the various application program overwhelming majority are all used BASIC, only when indivedual requirements realize the function of fast processing, just calls the program that the small number of machines sign indicating number is compiled.Like this, do not need special-purpose development system, the user just can utilize instrument itself, works out many for realizing the specific program of particular task easily.The address assignment of the 18K random read-write memory of adorning on the main frame (RAM) is: 26624-28671 is the buffer area of keyboard and magnetic tape station; 28672-30720 is the buffer area of display, from program in BASIC and the various variable of storage user more than 31465; The memory top is the stack area.If the user need use bigger internal memory, it can also be extended to 64K.

A M6847P chip is arranged, in order to the control CRT monitor on the motherboard.If as display screen, the modulator loop that vision signal is converted to TV signal is housed on the motherboard without display monitor central monitoring system but with televisor.In order to use blattnerphone to make external storage, also has the voice modulation loop on the motherboard.

2 keyboards

Adopt standard A SC II sign indicating number universal keyboard.

3 displays

Can adopt monochromatic display monitor central monitoring system or colour monitor, also can make display screen with televisor.

4 printer plotters

Printer plotter constitutes with servo principle, and black, blue, green and red four kinds of colors are arranged.Two stepper motors drive pen respectively and move in the horizontal direction and drive paper in movement in vertical direction.So it both can writing words, also can draw.This is to realizing the multi-functional very important of instrument.

5 magnetic tape stations and disk drive

Magnetic tape station and disk drive can be used as outside storage device, and the latter's advantage is that to deposit or take out the speed of program in very fast, but shake-proof ability difference and environment temperature is required relatively stricter.The situation of magnetic tape station is just in time opposite.Two kinds of peripheral hardwares have been designed in order to allow the user select for use according to actual conditions own.Disk system adopts the stronger DOS of function, SASIC interpretive routine.

6 digital-to-analog conversion loops

This part comprises among Fig. 16 digital-to-analog conversion integrated circuit and relevant operational amplifier, reference power source and decoding scheme, and D/A converting circuit adopts DAC 0832 chip.It has two latchs, during work six current and voltage data instrument is deposited in first latch, simultaneously data is delivered to second latch from first latch by code translator control then, through change-over circuit digital quantity is become analog quantity.This point is one of the measure that guarantees the phase accuracy of three-phase current voltage.

The voltage amplifier of 7 current source amplifiers

Current source amplifier and voltage amplifier play conclusive effect to the precision of this tester, and here precision comprises three aspects, the i.e. error of frequency, phase place and amplitude.For the controlled frequency error in the 0.1HZ scope, the present invention is the benchmark of host clock as work frequency, is clock because of main frame adopts quartz oscillator, its temperature coefficient is 10 ^-6To 10 ^-7Between, thus the instrument operating ambient temperature when 0 ℃ changes to 40 ℃, the cycle of clock does not have to change substantially, work frequency can not change yet.In order to guarantee phase error, except the D/A converting circuit that adopts dual latch, also has the phase place trimming circuit in current source and the voltage amplifier, to compensate the phase error that causes owing to used Resistor-Capacitor Unit numerical discretization in the whole loop less than once.To guarantee that at last amplitude error is less than one of percentage, except the very little reference voltage source of temperature coefficient is adopted in the digital-to-analog conversion loop, most importantly to guarantee that the power amplifier level has the voltage source or the current source characteristic of better performances, when promptly load changed within the limits prescribed, the voltage of output or the width of cloth of electric current were constant substantially.

The principle of current source amplifier and voltage amplifier as shown in Figure 2.Because the signal that comes from D/A converter is discontinuous staircase waveform, so will carry out filtering, signal is become smoother continuous wave.Before address, amplifier input terminal is connected to the phase place trimming circuit.Signal is by A then ₁Integrated operational amplifier is amplified to required amplitude.A ₂Be a power amplifier that is made of resolution element, its output is powered to the voltage circuit and the current return of tested protective device through transformer or current transformer, and output terminal has a negative-feedback signal through R simultaneously ₃And R ₉Be added to A respectively ₁And A ₂Input end, have the characteristic of voltage source or current source to guarantee amplifier.A ₃Be an integrated operational amplifier, its two input ends pass through C respectively ₁And R ₃Introduce the feedback signal that next signal in filtering and phase place adjustment loop and output are brought in, A during operate as normal ₃Output voltage is for negative, and is too big or when the brownout of power amplifier power supply is selected output filter shape distortion (mainly be the waveform top, amplitude reduces) when the output load of power amplifier, A ₃Positive ends input higher, its output potential is just becoming, and makes the diode of warning usefulness shinny, starts the audible alarm loop simultaneously.Fig. 3 is the wiring diagram of current source amplifier and voltage amplifier, with CT ₁And CT ₂A ', B ' and when the C ' A, the B that are connected to amplifier and C point, constitute current source amplifier, with PT ₁And PT ₂A ', B ' and when the C ' A, the B that are connected to amplifier and C point, constitute voltage amplifier.

Change-over switch K ₂, can change rated output voltage.With CT ₁5 secondary side coil connection in series-parallel can obtain 1A, 5A, 10A, five grades of output-current ratings of 25A and 50A.

8 frequency plot time measurement loops

Survey frequency, phase place and time three kinds of physical quantitys all use as shown in Figure 4 block diagram to finish.There is the two-way input signal in the loop, and the wiring of two paths is basic identical.Because input signal may be the alternating voltage or the pulse signal of relay contact, alternating current and various amplitudes, puts and is provided with K ₁To K ₁₂Two groups of key switchs are selected the kind and the amplitude of signal.Because the polarity difference of input pulse voltage, the closing of contact or open the current potential of also having introduced opposed polarity indirectly is so be provided with K ₁₃To K ₁₈Two groups of key switchs switch the signal of opposed polarity, to adapt to the requirement of back amplifying circuit.Amplifying circuit zooms into square wave to input signal among Fig. 4.Shaping circuit becomes this square wave the very steep pulse in forward position again, with the trigger flip-flop of the back of overturning reliably, produces signal strobe and removes to control counting circuit, K ₁₉To K ₂₁In order to select survey frequency, phase place or time function.

Fig. 5 is frequency, phase place and time measurement circuit wiring diagram and audible alarm loop.

During measured frequency, under CPU control, CTC ₁The umber of pulse of meter measured signal, CTC simultaneously ₂Begin to count the clock number of machine.Work as CTC ₁Behind the number (example is 201) of the full appointment of meter, read CTC ₂The clock number of being remembered.CPU is calculated as follows out the frequency of measured signal and is presented on the screen:

$\mathrm{f=}\frac{1}{t}=\frac{1}{{\mathrm{m\; \times \; <figure-callout\; id="1"\; label="t"\; filenames="88100626\_DRIMG5.png"\; state="\{\{state\}\}">t</figure-callout>}}_1\mathrm{÷\; n}}=\frac{n}{{\mathrm{m\; \times <figure-callout\; id="1"\; label="t"\; filenames="88100626\_DRIMG5.png"\; state="\{\{state\}\}">t</figure-callout>}}_1}$

Wherein: the cycle of t-measured signal

M-CTC ₂The clock number of being remembered

t ₁The cycle of-clock (unit is second)

N-CTC ₁The pulse of being remembered subtracts 1

When surveying phase place, CPU reads 200 interior CTC of cycle of measured signal earlier ₂Control the clock number of being write down without gate, and then read CTC in the same time ₂Through the clock number that gate control is write down, calculate the phase place between two measured signals with following formula then and be presented on the screen.

φ=(m ₂* 360)/(m ₁) (degree)

Wherein: the angle of φ-signal 1 anticipating signal 2.

m ₁The clock number that 200 interior CTC2 of cycle of-measured signal are remembered without gate control.

m ₂-measured signal is controlled the clock number of being remembered through gate in 200 cycles.

Measuring Time has the branch of single input quantity and dual input amount, and width, the normally closed contact of measurement positive negative pulse stuffing voltage opens the time or the normally opened contact closure time only needs signal of a passage access on Fig. 4.This signal removes to control CTC through functional select switch again through zooming into square wave ₂Gate circuit.CPU can calculate the duration of this signal by following formula and be presented on the screen.

t＝m×t ₁

Wherein:

The width of t-measured pulse (ms)

N-CTC2 institute time clock number subtracts 1

t ₁The cycle of-each time clock (ms)

When measuring the time interval of two interpulse or contacts deciliter, need two measured signals are added on two input ends shown in Figure 4 respectively.First measured signal this moment puts 1 with trigger flip-flop, and promptly starting gate is by CTC ₂Counting, second measured signal put O with bistable, closed shutter CTC ₂Stop counting.CPU reads CTC ₂Institute's time clock number can be calculated the result by following formula.

Use this tester, can improve the testing level of China's relay protection of power system and some aut.eq. widely.Owing to will manually change into automatically, accelerate detection speed, shorten and be transported to electric equipment owing to detect the power off time of protection, national economy there is positive effect.Not only simple electric current, voltage and frequency relay can be tested with this device, and the complicated protective relaying device of many performances can be tested.For example: it can produce the electric current and the voltage in 150,250 and 350 weeks, to adjust 3 times, 5 times and 7 subharmonic resonant tanks; Can test the angular characteristics of whole impedance relay, directional impedance relay and the offset characteristic impedance relay of round characteristic automatically, the measurement impedance and the actuation time of drawing the characteristic circle automatically and printing each point; Produce three-phase current that angle and amplitude can change arbitrarily with the debugging high frequency longitudinal difference protection of differential protection and generator transformer mutually, draw braking curve automatically; Produce the three-phase current and the voltage of superposition each harmonic on the first-harmonic, with of the influence of check harmonic wave to relay protection.As electric current, test the transformer differential protection that constitutes with various principles and keep away the ability of excitation surge current more with the superposition second harmonic; Because the frequency of output voltage and electric current is adjustable, so can be used to the influence of test frequency variation to various protections; When dynamical fashion was worked, output can be transformed into malfunction by normal operating condition, otherwise or.The phase place of conversion moment three-phase current and voltage is controlled.This behavior of protecting when studying specific switching angle is very convenient.

The present invention has the function of survey frequency, phase place and time three kinds of physical quantitys, and is also very favourable to the debugging work of relay protection.The frequency of its energy measurement 20-1000HZ curtage; Phase differential between the identical curtage of energy measurement two frequencies; The time interval between energy measurement relay contact closure time or the time of opening, positive pulse width and negative pulse width and two signals.It " plays " " ending " signal can be that open relay contact closure, contact, the positive pulse curtage, 36 kinds of combinations such as negative pulse curtage.

List of references

1.TS-3 type protective device testing table (power station equipment robotization) 1980.6

2.MODELF3-C F3-D 3 φTEST SYSTEM Operating Manual Doble Engineening Company U、S、A

3.7VP461，7VP47 TEST SYSTEM SLEMENS COMPANY

4. higher hamonic wave is to being translated from (3 ∧ KTPn4e CRMe CTaHynn) 1978 NO.8 through the relay protection of condenser divider access and the influence (power station equipment robotization) 1981.2 of aut.eq. work

5. the ground current higher hamonic wave is to zero sequence electric protection action influence (relay collected translation) 1985.2

6. the development Ministry of Water Resources and Power Industry Nanjing Automation Research Institute of the comprehensive humorous wave generating device used of reaying protection test

7. micro-processor controlled relay debugging device Ministry of Water Resources and Power Industry Nanjing Automation Research Institute

8.AN AUTOMATED TESTING SYSTEM FOR DISTANCE RELAYS IEEE Transactions on Pawer Apparatus and Systems，Vol，PAS-96 NO.4，July/August 1977

9.New，Fully Automatic Means of Testing Generator Protection Equipment Brown Boreri Rev.2-77

10. using the relay test self-recording unit makes relay test rationalize (day) four countries Utilities Electric Co.

11.A Programmable Test Unit for Line and Feeder Protection Brown Boveri Rev Vol 72 No2 1985

Claims (3)

1; a kind of by microcomputer; counting/timer; the micro-computer controlled multifuncitonal that digital to analog converter and power amplifier the are formed protection tester that continues; it is characterized in that the controlling function that main frame is used to calculate the first-harmonic and the higher hamonic wave of output current and voltage and is responsible for instrument; the CTR display both had been used to show various programs and had realized the full-screen editing function; the definite value and the test result that show output quantity again; the drawing printer is used to print various specific programs; definite value; test result and draw the family curve of tested protection; magnetic tape station or disk drive are used to store various specific programs and data; call in calculator memory in case of necessity to realize certain specific function of tester, current source amplifier and voltage amplifier are by filtering and phase place adjustment; the prime operational amplifier is formed with the power amplifier that separates the original paper formation.

2, the described relay-protection tester of a kind of claim 1 is characterized in that current source and voltage amplifier adopt multistage negative feedback connection.

3, the described relay-protection tester of a kind of claim 1 is characterized in that the input signal treatment circuit is made of two paths of signals and amplitude selection circuit, polarity switching, amplification integeral type circuit and shared bistable state gate circuit and function selector circuit.

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