SU1385083A1 - Resistive current component transducer - Google Patents

Abstract

The invention relates to a measuring technique for determining the active current of non-linear loads of power supply systems. The sensor of the active component of the current contains the adder 7, the sensors 2, 1 of the current and voltage, respectively, synchronization unit 3, instantaneous value measurement unit 4, control unit 5, signal signal detection unit 6, averaging 8. In the description of the invention, the electric circuit of adder 7 is shown and averager 8. The sensor has a higher accuracy of active current release. 2 hp f-ly, 7 ill.

Description

The invention relates to a measurement technique for determining the active current of non-linear loads of an electrical supply system.

The aim of the invention is to improve the accuracy of the active current release.

FIG. 1 shows the structural removal of the device; in fig. 2 - diagram of the synchronization unit; in fig. 3 is an instantaneous measurement unit; in fig. 4 - control unit; in fig. 5 shows a signal determining unit; FIG. 6 - adder; in fig. 7 - averager.

The device (Fig. 1) contains a voltage sensor 1, a current sensor 2, a synchronization unit 3, the output of which is connected to the first input of the instantaneous value measurement unit 4 and the fifth input of the control unit 5, the output of the current sensor 2 is connected to the input of the unit 6 determining the sign of the signal, the first output of which is connected to the second input of the instantaneous value measurement unit 4, the second and third outputs of the signal detection unit 6 is connected to the fifth and sixth inputs of the adder 7, two outputs of which are connected to two inputs of the amplifier 8, respectively The device is the first device, the first three inputs of the adder 7 are connected to the three outputs of the control unit 5, the fifth output of the unit 4 measuring the instantaneous values is connected to the fourth input of the adder 7.

The synchronization unit 3 contains (FIG. 2) a pulse shaper 9, whose input is the input of block 3, and the output is connected to the inputs of the positive element 10 and the negative pulse element 11, the output of the latter through the inverter 12 is connected to the first input of the element 13 OR, the output of which is connected to the output 14 of block 3, and the second input is connected to the output of the element 11 for positive pulses.

The instantaneous value measurement unit 4 (FIG. 3) contains a generator 15, the output of which is connected to the counting input of the counter 16 and the first inputs of the elements 17 and 18, the reset input of the counter 16 is the first input of the block 4, the output of the counter 16 is connected to the S input trigger 19, the first input of element 20 OR, and through an inverter 21 with the second input of element 20 OR and the R input of the trigger 19, direct output

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which is connected to the second input element 17 And, the output of which is connected to the second output of the block 4 and the first input of the element 22 OR, the second input of which is connected to the first output of the block 4 and the output of the element 18 And, the second input of which is connected to the inverse output of the trigger 19, the output element 22 And connected to the third output of block 4 and the first input element 23 And, the second input of which is connected to the output of the null indicator 24, the first input of which is connected to the second input of block 4, and the second input through digital-analogue repeater (DAL) 25 connected to the output account ika 26, a counting input coupled to a fourth output unit 4 and the output of the element 23, the control input of the counter 26 is connected to the output of OR gate 20.

The control unit 5 (Fig. 4) contains the .27-29I elements, the first inputs of which are connected together and with the first input of the unit 5, the S input of the trigger 30. connected to the second input of block 5, the third input of block 5 is connected. with the R input of the trigger 30, the direct output of which is connected to the second input of the element 27 AND, the output of which is connected to the first input of the element 31 OR, the second input of which is connected to the output of the element 28 AND, the second input of which is connected to the inverse output of the trigger 30, p The first input of the block 5 is connected to the S-input of the trigger 32, the output of which is connected to the second input of the element. And 29 AND and the first inputs of the elements 33, 34 and 35 of RSHI, the fourth input of the block, 5 is connected to the second input of the element 34 And through the inverter 36 with the second input element 33 And, the output of which is connected to the third output the house of block 5, its second output is connected to the output of IDN element 35, the second input of which is connected to the output of element 31 OR and through the inverter 37 to the third input of element 34 AND whose output is connected to the first output of block 5, the output of element 29 AND is connected to the counting input of the counter 38, the output of which is connected to its own reset input and the R input of the trigger 32.

Signal detection unit 6 (Fig. 5) contains a pulse shaper 39, whose input CC5 is unified with the input of block 6 and the input of shaper 40 of the amplitude signal, the output of which is connected to the first output of the block

6, the output of the pulse driver 39 is connected to the inputs of the A1 drivers and 42 positive and negative pulses, respectively, the output of OO, the last one via inverter A3 is connected to the R input of the trigger 44, S-in turn, which is connected to the output of the A1 driver of positive pulses, direct and inverse outputs of trigger 44 are connected to the second third outputs of block 6.

The adder 7 (Fig. 6) contains the elements 45 and 46 And the first inputs of which are connected together with the third input of the adder 7, the first input of the adder 7 is connected to the reset inputs of counters 47 and 48, the second input of the adder 7 is connected to the second input of the element 45 And the output which is connected to the counting input of the counter 47. the third input of the adder 7 is connected to the second input of the element 46 And the output of which is connected to the counting input of the counter 48, the fifth input of the adder 7 is connected to the first inputs of the elements 49 and 50 And whose outputs are connected to the first and the second inputs of the adder 51 codes the reset input of which is connected to the sixth input of the adder 7, the second input of the element 49 And connected to the output of the counter 47, the second input of the element 50 is connected to the output of the counter 48, two outputs of the adder 51 codes connected to the corresponding inputs of the adder 7.

Averager 8 (FIG. 7) contains a DAC 52, the input of which is connected to the second input of the block 8, the first input of which is connected to the control input of the switch 53, the input of which is connected to the output of the DAC 52, the first output of the switch 53 is connected to the first input of the summation element 54, the output of which is connected to the output of block 8, the second input of the summation element 54 through the inverter 55 is connected to the second output of the switch 53.

The device works as follows.

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sync pulses at times of voltage crossing through zero, which synchronize the operation of control unit 5 and instantaneous value measurement unit 4.

The generator 15 in block 4 measuring the instantaneous value sets the reference pulse frequency, through a log

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elements sia input counter 26, the output of which through the PAP 25 is connected to the input of the null indicator 24, the second input of which receives a signal from the current sensor 2. At the moment of coincidence of the signals at the input of the null indicator 24, a pulse appears at its output, which stops the operation of the counter, the state of which is proportional to the measured current value, and at the fifth output of block 4 (output of element 23 AND) the number-pulse code is generated proportional to the measured value of the current modulus (current ordinate).

In the adder 7, the counter 47 forms a binary code proportional to the sum of the positive Ordinates of the input current, and the counter 48 - negative, the adder 51 codes produces the summation of codes.

The binary code from the output of the adder 7 is fed to the input of the DAC 52 and through the switch 53 and the summation element 54 to the device's external code.

Thus, the device produces a numerical integration of the measured current, which eliminates the influence of higher harmonics and thereby improves the accuracy of the active current release.

Claims (3)

Invention Formula 1, Active current component sensor containing an adder, a current sensor and a voltage sensor, the output of which is connected to the input of a synchronization unit, characterized in that, in order to improve accuracy, an instantaneous value measuring unit, a control unit, an adder, a unit are entered into it determining the sign of the signal, the averager, the four outputs of the instantaneous value measuring unit are connected to the corresponding four inputs of the control unit, three outputs of which are connected to the corresponding inputs of the adder, two outputs of which are connected with the corresponding inputs of the averager, the output of which is connected to the output of the current sensor, the current sensor is connected to the input of the sign determining unit, the first output of which is connected to the second input of the instantaneous value measuring unit, the first input is connected to the output of the synchronization unit and the fifth input of the control unit, the fifth output of the instantaneous measurement unit is connected to the fourth input of the adder, the fifth and sixth inputs of which are connected to the second and third outputs of the sign determining unit. 2, A current sensor in accordance with claim 1, characterized in that the adder contains four AND elements, two counters and a code adder, the first input of the adder is connected to the reset inputs of the first and second counters, the second input of the adder is connected to the second input of the first element AND , the first inputs of the first and second elements And connected together and with the third input of the adder, the output of the first element And connected to the counting input of the first counter, the output of which is connected to the second input of the third element And, the first inputs of the third and fourth elements And connected There is also a fifth input of the adder, the third input of which is connected to the second input of the second element I, the output of which is connected to the counting input of the second counter, the output of which is connected to the second input of the fourth element And, the outputs of the third and fourth elements And are connected to the first and the second input of the adder codes, the reset input of which is connected to the sixth input of the adder, two outputs of the adder codes connected to the corresponding outputs of the adder. 3. The current sensor according to claim 1, characterized in that the averager contains a digital-to-analog converter, the input of which is connected to the second input of the averager, and the output is connected to the input of the switch, the control input of which is connected to the first input of the averager, the first output of the switch is connected to the first input summation element, the second input of which through the inverter is connected to the second output of the switch, the output of the summation element is connected to the output, the course of the averager. FIG. 2 s V1 32 jgTM-i Jv (Pus. FIG. five 52 fie. 7 Fi.b L her - 55