SU1064233A1 - Device for measuring three-phase network quality index - Google Patents

Abstract

1.USTROYSTVO FOR MEASURING POWER QUALITY INDICATORS three-phase network, comprising: an input summing scale-converter switch-code converters voltage and voltage-code multiplying unit frequency block forming constants, combinational adder, the calculator, and the indicator control unit, wherein three input terminals through the input scale-summing converter are connected to the three inputs of the switch, the output of which through the converter is connected to the voltage input connected to the converter input The i-code, the output of the first combinational adder is connected through the -constant shaping unit, to the control input of the code-voltage converter, one of the input terminals through the frequency multiplier unit is connected to the synchronization input of the control unit, the first, second, third and fourth output terminals of which are connected with the control inputs of the switch, combinational adder, voltage converter-code and calculator, the output of which is connected to an indicator, characterized in that, in order to enhance the functionality and speed, code converter, combinational and accumulating adders, memory block, with three additional outputs of the input scale-summing converter connected to three additional inputs of the switch, the output of the voltage-voltage converter through a serially connected code converter, the second-hand combinational adder, the memory unit is connected to the calculator, the output of the memory unit is connected to the control input of the second combiner adder, the output of the accumulating sum ora coupled to the first Raman adder, fifth, sixth, and seventh outputs of the control unit are connected with the control input transducer codes the accumulator and the memory unit respectively. 2. The device according to claim 1, .o t lchayuscheys the fact that. the control unit contains an IMO O) pulses distributor, a counter, a decoder and a control logic circuit, the counter counting BxoA-j through the spreading t4D pulse divider is connected to the synchronization input of the control unit, the decoder inputs CO of the second, third and last bits of the counter , two inputs of the logic circuit are connected to the third and fourth outputs of the pulse distributor, four other inputs of the logic circuit are connected to the outputs of the first, second, third and last bits of the counter, with m outputs of the decoder are controlling the first output unit outputs the first and penultimate bit counter rows of second and fourth output block. control, the first and second outputs of the pulse distributor - the sixth and third outputs of the control unit, and the outputs of the logic circuit

Description

fifth and seventh outputs of the control unit.

3, the Device in PP. 1 and 2, characterized in that the input scale-summing converter contains a voltage divider and a scale-summing converter, the three inputs of the voltage divider being inputs of the input scale-summing converter, and three outputs of the voltage divider are connected to the inputs of the scale the summing converter and the three outputs of the input scale-summing converter, the three outputs of the scale converter are the three other outputs of the input scale-summing, conversion Vatel.

one

The invention relates to a measurement technique and can be used to determine the quality of electricity quality indicators (voltage deviation, non-symmetry factors and three-phase network voltage imbalances), which are normalized by GOST 13109-67, as well as to measure the levels of phase voltage harmonics and symmetrical components three-phase network voltage. ,

A device for measuring the symmetrical components of a three-phase network voltage is known, comprising a generator, a phase shift unit, an indicator, a scale-sum converter, a switch., A multiplier, a frequency multiplier, a pulse code converter, low-pass filters, and tl keys.

The disadvantage of this device is a low response rate due to the long duration of the measurement cycle (4 periods) and the need to balance the phase angle.

The closest to the proposed technical essence and the achieved result is a device for measuring the symmetrical components of the three-phase network voltage, containing a scale-summing converter, a switch, two keys, a code-voltage converter, a voltage-code converter, a frequency multiplier, a counter , register, combinational adder, constants forming unit, computational display unit, logic circuits and control unit 2.

However, the known device can measure only one parameter at a time. In order to obtain complete information on power quality indicators, it is necessary to simultaneously measure all power quality indicators, not only by symmetrical components, but also by phase voltages.

The purpose of the invention is to enhance the functionality and increase speed.

The goal is achieved by having a device for measuring power quality indicators of a three-phase network containing an input scale-summing converter, a switch, code-voltage converters, and voltage-code, a frequency multiplication unit, a const. Forming unit, a combinational adder, calculator, indicator, and. the control unit, the three input terminals through the input scale-summing converter connected to the three inputs of the switch, the output KOiPoporo through the converter, the voltage connected to the input of the voltage-code converter, the output of the first combinational adder through the unit of formation of constants connected to the control input of the converter- voltage, one of the input terminals through the frequency multiplying unit is connected to the synchronization input of the control unit, the first, second, third and fourth outputs of which are connected to the pack Auxiliary inputs of the switch, combinational adder, voltage converter-code and calculator, the output of which is connected to the indicator, a code converter combining and accumulating adders, a memory unit, and three additional outputs of the input scale-summing converter, are connected to three additional inputs of the switch, voltage-code converter output through serially connected code converter, second combination adder, memory block is connected with computer, output One of the dam unit is connected to the control input of the second combiner adder, the output of the accumulating adder is connected to the first combinational adder, the fifth, sixth and seventh outputs of the control unit are connected with the control inputs of the code converter, the accumulator adder and the block, respectively. The control unit contains a pulse distributor, a counter, a decoder and a control logic, with the counting input of the counter through the pulse distributor connected to the synchronization input of the control unit, the decoder inputs are connected to the outputs of the second, third and last bits of the counter medianne with the third and fourth outputs of the pulse distributor, four other inputs of the logic circuit connected to the outputs of the first, second, third and last bits of the counter while the outputs are decoded The first outputs of the control unit; the outputs of the first and previous, last bits of the counter — the second and fourth outputs of the control unit; the first and second outputs of the pulse distributor — the sixth and third outputs of the control unit; and the outputs of the logic circuit of the fifth and seventh outputs up- The input scale but-summing converter contains a voltage divider and a scale-summing converter, the three inputs of the voltage divider being inputs of the input-scale summing converter, and the three outputs of the voltage divider are connected to the inputs of the master voltage The dater converter and the three outputs of the input scale-summing converter, the three outputs of the scale-up converter are the three other outputs of the input scale-summing converter. The drawing shows a block diagram of the proposed device. The device contains input scale-summing converter 1, consisting of voltage divider 2 and scale-summing converter -3, switch 4, code-voltage converter 5, voltage-voltage code-6 converter, code-6 converter , combiner adder 8, memory block 9, calculator 10, indication unit 11, unit for constants formation 12, combinational adder 13 accumulating adder 14, frequency multiplying unit 15, control unit 16 with outputs 17-23 consisting of a distributor 24 impulseia, tick counter 25, descrambler 26 and logic circuit 27. The input buses 28-30 through the input scale-summing converter 1, switch 4, and code-to-voltage converter 5 are connected to the input of voltage converter 6, code (inc), and switch 4 is equipped with additional inputs that are connected to the additional outputs of the converter 1, namely to the outputs of the divider 2 voltage. The outputs of PNK 6 are connected via the converter 7 of the code, the combinational adder 8, the memory block 9 and the calculator 10 to the inputs of the display unit 11, and the outputs of the memory block 9 are also connected to the other inputs of the combinational accumulator 8. The control inputs of the PCN 5 through block 1 The -2 constant constants and the combinational adder 13 are connected to the outputs of the accumulating adder 14, to the inputs of which the code K of the number of the measured harmonic is applied. Bus 28 is connected via frequency multiplying unit 15 to the synchronization input of the block, 16 controls. The outputs 17-23 of the block 16 are connected respectively to. control inputs of switch 4, adder D4, adder 13, PNK 6, converter 7 of code, memory block 9 and calculator 10. Synchronization input of block 16 through a distributor 24 pulses connected to the output of counter 25, the outputs of the second, third and last bits of which are connected with decoder 26. The inputs of circuit 27 are connected to the third and fourth outputs of the distributor 24 and the outputs of the first, second, third and last bits of the counter 25. The outputs of the decoder 26 are the outputs 17 of block 16, the outputs of the first and second to last bits of the counter 25 - Exit 19 and 3 blocks 16, the first and second outputs of the distributor 24 - 18 and 20 outputs block 16, and the outputs of the logic circuit 27 to - 21, and output unit 16. The apparatus 22 operates as follows obrazbm. One cycle of operation of the device corresponds to two periods of input voltage Od. In the first period, the symmetric components of the voltage are determined, and in the second, the phase voltages of the K -h harmonics are determined. The operation of the device is synchronized by the output pulses of the frequency multiplying unit 15, the follow-up period of which is, where T is the voltage period Od j N is the frequency multiplication factor. Each output pulse of the frequency multiplying unit 15 is fed to the synchronization input of the control unit 16, namely, the trigger input of the pulse distributor 24, by which signals are generated in the time interval between the output pulses of the frequency multiplying unit 15. The last output pulse of the distributor 24 is fed to the counting input of the counter 25. The output code n of the counter 25 corresponds to the number of the output pulse of the frequency multiplier 15. So, the cycle time of the device is equal to two periods of the input voltage, during which 2H pulses go to the counting input of the counter 25, the output code of the counter 25 takes values from up to 2N-1, the Output code n also corresponds to the output pulse number of the block 15 multiplying the frequency, which is counted from the beginning of the cycle of operation, while in the first period n varies from O to N-1, and in the second, from N to 2N-1. Signals to you. moves 18, 19, 20 and 23 of block 16 co. correspond to the signals on the corresponding outputs of the distributor 24 pulses and the counter 25. The signals on the output channels 17 correspond to the output signals of the decoder 26. Since the decoder 26 is connected to the outputs of the counter 25, these signals are determined only by the output code n of the counter 25. The signals at the outputs 21 and 22 of the block 16 correspond to the output signals of the logic circuit 27, since the circuit 27 is connected to the outputs of the counter 25 and is distributed to 24, these signals are defined as the output code n of the counter 25, so the output signals p the distributor 24 pulses. The input voltages are supplied through a divider 2 of the voltage on the inputs of the scale-summing converter 3. The output voltages of the converter 3 are equal:. - 1. and LL-4-uu, .fu ,, where Id, Ug, I (- output voltages, divider 2, proportional voltages on the inputs of the device. Uc I i Voltage ID. OC through switch 4 arrive at the analog input of the VCP 5. The sequence of connection of these voltages is determined by the signals at the outputs 17 of block 16, which are fed to the control inputs of the switch 4. In the first period, when the output code of the counter 25 takes the values O, 1, 6 , 7, 12, 13, ..., N-5, N-6, the analog input of PKN 5 through the switch 4 receives the voltage and, with n 2, 3, 8, 9, 14, 15, ..., N-4, W-3 - voltage Uj; with 4/5, 10, 11, 16, 17, ..., n-2, N-1 is the voltage and, in the second period, with n N, N + 1, And + 6, N + 7, ... , 2N-6, 2N-5 - voltage DC, with n N + 2, N + 3, N + 8, M + 9, ..., 2N-4, 2N-3 - voltage Ug, with n N +4, N + 5, N + 10, N + 11, ..., 2N-2, 2N-1 is the voltage U. The pulse at the output 18 of the block 16 corresponds to the signal at the first output of the distributor 24 and is fed to the control input of the accumulator adder 14. At the same time, the K code on its input buses is added to its previous state. After the n-th pulse multiplier 15 frequency code at the outputs of the adder 14 is equal to mod j PC. This code through the combinational adder 13 is fed to the inputs of the block 12 of the formation of constants. Moreover, if the control input of the adder 13, which is connected to the output 19 of the block 16, namely the output of the first discharge of the counter 8, is logical 1, then the code K / 4 is added to the code at the input of the adder 13, and if the logic is. If the input and output codes of the adder 13 are the same. Therefore, if the output code of the counter is 25 even, i.e. п О, 2, 4, ..., 2Н-2, then on the block 12 will be in the code w; equal to niod yu PK I and for odd n, i.e. when n 1,3,5, ..., 2N-1, the input of block 12 will be rnod 1 (n К + N / 4.). The control inputs of PKN 5 receive constants from the output of constant formation block 12, the values which are equal to 51П (n, are determined by the MP code on the inputs of block 12. Thus, when n 0,2,4, ..., 2il-2, the constants Sin 2ji / N (mod pc) I are received at the input of the PCN 5 and with n 1, 3.5, ..., .- 1 - constants 3in 2Jr / N (mocl)) i (nK + N / 4)). Accordingly, the transmission coefficient of PKN 5 is equal to sin - pc or cos 2JT / M PC. Using the PCN 5, the signal is multiplied by its analog 2J7 input to the code Sin tt I / n or COS cj, P. The output signals of the PCN 5 are converted into Xg codes, using the NCP 6 at the moment the control output from the block 20 arrives 16, i.e. from the second output of the distributor. The output code of the OSP 6 comes through the converter 7 of the code to the input of the combinational adder 8. In this case, if the control input of the converter 7, which is connected to the output 21 of the block 16, is logged

Claims (3)

1. DEVICE FOR MEASURING ELECTRICITY QUALITY INDICATORS • A THREE-PHASE NETWORK containing an input scale-sum converter, a switch, code-voltage and voltage-code converters, a frequency multiplier, a constant generation unit, a combinational adder, a calculator, an indicator and a control unit, three input terminals through the input scale-sum converter are connected to three inputs of the switch, the output of which through the converter, the voltage code is connected to the input of the voltage-to-converter e, the output of the first combinational adder is connected through the α-block of constant formation, to the control input of the code-voltage converter, one of the input terminals through the frequency multiplier is connected to the synchronization input of the control unit, the first, second, third and fourth outputs of which are connected to the control inputs of the switch combination combiner, voltage-code converter and calculator, the output of which is connected to an indicator, characterized in that, in order to expand the functionality and increase the speed action, a code converter, combinational and accumulating adders, a memory block are introduced into it, and three additional outputs of the input scale-sum converter are connected to three additional inputs of the switch, the output of the voltage-code converter through a series-connected code converter, the second combination adder, a memory block connected to the calculator, the output of the memory unit is connected to the control input of the second combination adder, the output of the accumulating adder is connected to the first combinational adder, the fifth, sixth and seventh outputs of the control unit are connected to the control inputs of the code converter, accumulating the adder and the memory unit, respectively. 2. The device according to π.Ι, .ο tl liable in that. the control unit contains a pulse distributor, a counter, a decoder and a control logic, moreover, the counter counter input via a pulse distributor is connected to the synchronization input '' of the control unit, the decoder inputs are connected to the outputs of the second, third and last bits of the counter, two logic inputs are connected to the third and the fourth outputs of the pulse distributor, the four other inputs of the logic circuit are connected to the outputs of the first, second, third and last digits of the counter, Ora are the first output of the control unit, the outputs of the first and penultimate bits of the counter, the second and fourth outputs of the block. control, the first and second outputs of the pulse distributor - the sixth and third outputs of the control unit, and the outputs of the logic circuit SU „1064233 fifth and seventh outputs of the control unit. 3. The device according to paragraphs. 1 and 2, characterized in that the input scale-sum converter contains a voltage divider and a scale-sum converter, the three inputs of the voltage divider being the inputs of the input scale-sum converter, and the three outputs of the voltage divider are connected to the inputs of the scale-sum converter and three outputs of the input scale-sum converter, the three outputs of the scale-sum converter are three other outputs of the input scale-sum converter. transducer.