RU2145716C1 - Power characteristics analyzer - Google Patents

Abstract

FIELD: electric measurement technology. SUBSTANCE: analyzer has input device, power supply, programmable signal processing unit, processor-to- processor interface, central processor unit, data display facility, two random-access memory devices, conversion and control device, and pulse parameter measuring device. Analyzer incorporates provision for measuring parameters in all phases simultaneously. EFFECT: enlarged functional capabilities. 2 cl, 6 dwg

Description

 The invention relates to electrical engineering and is intended to measure indicators of the quality of electrical energy.

 A device is known for measuring electrical parameters in three-phase networks (see AS USSR N 1478139 G 01 R 19/35).

 The known device also measures the active and reactive components of the current. The device contains three current and voltage transformers, a zero-organ, a buffer unit, a recorder, a frequency divider, a trigger, and I. elements. The control unit of the corresponding commands, through an analog switch, connects transformers in series to an analog-to-digital converter. The zero-organ determines the moment when the voltage passes through zero in the corresponding phase of the network, and the generator, frequency divider, AND elements and OR element, the trigger and the reversible counter determine the period of the corresponding voltage, as well as a quarter of the period and other measurement moments. The register stores information about the period. The buffer unit and the recorder record and display information from the ADC output.

 The closest solution to the claimed one is the P513 oscilloscope ("Description of the design and operation", St. Petersburg, Conference Materials, September 1998), containing an input device connected to a power supply, a programmable signal processing unit, an interface, a central processor, display means (display) and corresponding system buses.

 The disadvantages of the known technical solutions is the impossibility of continuous comprehensive measurement of all indicators of the quality of electricity at the same time in all phases with the required accuracy.

 The technical result of the claimed solution is the expansion of functionality due to the continuous comprehensive measurement of all indicators of power quality at the same time in all phases with the required accuracy.

 The specified technical result is achieved by the fact that the electric energy quality analyzer containing an input device configured to normalize the voltage signals and phase currents and phase currents of the network and the ground wire of the network and to separate voltage signals into narrow-band and wide-band pulse components is one of the information inputs the input device is connected to a power supply, the inputs of which are supplied with phase voltage signals, the analyzer also contains a series connection The programmable signal processing unit, the interprocessor communication interface, the central processor and the information display device were introduced via the system bus, two random access memory devices connected by bidirectional buses with the interprocessor communication interface were introduced, while the system buses are bi-directional, the conversion and control device and the measuring device are also introduced pulse parameters, the scaling outputs of which are designed to form scale signals on them, connected to the control inputs of the input device and the conversion and control device, and the outputs of the pulse parameters are connected to the corresponding inputs of the conversion and control device, the information output of which is connected to the input of the programmable signal processing unit, the other outputs of the conversion and control device are connected to the corresponding control inputs of the reset signals for synchronization device for measuring pulse parameters, the other inputs of which are connected to broadband outputs an input device intended for supplying narrow-band pulse component signals to the corresponding inputs of a conversion and control device containing three switches, a high-frequency generator, a frequency grid generator, an inverter, a driver configured to generate a signal with a network frequency from phase voltage signals, a phase adjustment device frequency, signal shaper, configured to generate, in response to signals with a network frequency, reset signals for synchronizing impulse parameter measurement devices, an analog-to-digital converter designed to convert analog normalized signals of currents and phase voltages and ground wire into a serial code, a code modification unit designed to enter into the serial code information about the sequence of broadband signals through the channels of the pulse parameter measurement device and on the scale of the signals of currents and voltages of phases and ground wire, and two sampling and storage devices designed to supply signals to the information inputs of the respective switches, through which the sampling and storage devices are connected to the information input of an analog-to-digital converter, the output of which through the code modification block is connected to the information input of the programmable signal processing unit, the driver is connected in series with the phase adjustment block, the frequency grid generator, and the high-precision generator designed to supply a clock signal to the control input of an analog-to-digital converter, the inputs of one of sampling and storage devices are connected to narrow-band inputs of the conversion and control device, the information input of the second sampling and storage device is connected to the output of the third switch, the inputs of which are connected to the outputs of the pulse parameters of the device for measuring pulse parameters, the outputs of the frequency grid generator are connected to the corresponding control inputs of the switches, one from the sampling and storage devices, to the former, the code modification unit and the inverter, the inverter output is connected to the control input the second sampling and storage device and with another control input corresponding to this sampling and storage device of the switch to ensure the operation of one sampling and storage device with the corresponding switch in antiphase to the second sampling and storage device with the corresponding switch, the input of the driver is connected to the information inputs of the input device, the outputs of the driver signals are connected to the control inputs of the device for measuring pulse parameters, the corresponding scaling the output of which is connected to the corresponding input of the code modification block.

 An impulse parameter measuring device consists of four identical channels, with one channel containing comparators of positive and negative signals, peak detectors of positive and negative signals, integrators of positive and negative signals, a signal shaper for zooming, adders for the duration of positive and negative signals, and counters of positive and negative signals, and the information inputs of peak detectors, integrators and comparators are connected respectively to and information channel input, intended for receiving signals from the broadband outputs of the input device, the control inputs of the peak detectors of positive and negative signals, integrators of positive and negative signals, adders duration of positive and negative signals and counters of positive and negative signals are connected to the channel input, intended for receiving signals reset, information inputs of the adder and the counter of positive signals and one of the inputs of the shaper the zoom signal is connected to the output of the comparator of positive signals, the information inputs of the adder and the counter of negative signals and the other input of the shaper of the signal to change the signals are connected to the output of the comparator of negative signals, the outputs of the peak detectors of positive and negative signals, integrators of positive and negative signals, adders of durations positive and negative signals, counters of positive and negative signals, and signal shaper ba connected to respective outputs of pulse parameters of the pulse measurement device.

 In FIG. 1 is a structural diagram of an electric energy quality analyzer; in FIG. 2 - device for measuring the pulse parameters of one of the channels; in FIG. 3 - device conversion and control; in FIG. 4 (a, b, c) - time diagrams.

 The electric energy quality analyzer contains an input device 1, a power supply 2, a device for measuring pulse parameters 3, a conversion and control device 4, a programmable signal processing unit 5, an interprocessor communication interface 6, a first random access memory 7, a second random access memory 8, a central processor 9 and display means (not shown).

 The conversion and control device 4 contains two sampling and storage units 11 and 12, three switches 13, 14 and 15, an analog-to-digital converter (ADC) 16, a code modification unit 17, a high-frequency generator 18, a frequency grid generator 19, an inverter 20, a shaper 21, a phase adjustment block of frequency 22 and a signal conditioner 23.

 The device for measuring the pulse parameters 3 of one of the channels contains comparators 24 and 25 of positive and negative signals, peak detectors 26 and 27 of positive and negative signals, respectively, integrators 28 and 29 of positive and negative signals, a shaper 30 of the zoom signal, adders of duration 31 and 32 positive and negative signals, counters 33 and 34 of positive and negative signals.

 The analyzer operates on the quality of electrical energy as follows.

 The information inputs of the input device 1 (see Fig. 1) receive signals of phase currents and ground wire of a 50 Hz network: IA, IB, IC, IG (IX), as well as phase and ground voltages UA, UB, UC, UG ( UX).

The control inputs of the input device 1 from the scaling outputs of the device for measuring pulse parameters 3 receive control signals of the voltage scales M _a , M _b , M _c , M _g (M _x ). The input device 1 normalizes the signals IX and UX and separates the voltage signals into narrowband components UX and broadband pulse components U _{x and} .

From the narrow-band outputs of the input device 1, the normalized signals of the currents I _a , I _b , I _c , I _g (I _x ) and voltages U _a , U _b , U _c , U _g , (U _x ) are fed to the same inputs of the conversion and control device 4.

In addition, from the broadband outputs of the input device 1, the normalized pulse components of the network voltage U _au , U _bu , U _cu , U _gu (U _xu ) are supplied to the same inputs of the device for measuring pulse parameters 3. When a signal _{exceeds the} established threshold U _x measuring pulse parameters 3 generates the corresponding signal M _x , which is used in the input device 1 to change the scale of the corresponding signal U _x and in the conversion and control device 4 for entering information about the scale of the signals U _x .

 The inputs of the power supply 2 are supplied with phase voltages UA, UB, UC, from the outputs of which the analyzer supply voltage + 5V, ± 12V is removed.

The control inputs of the device for measuring pulse parameters 3 from the corresponding outputs of the conversion and control device 4 receive reset signals R _a , R _b , R _c , R _g (R _x ), under the influence of which the signal generation is synchronized in the device for measuring pulse parameters 3.

From the outputs of the pulse parameters of the device for measuring pulse parameters 3, the signals of the values of the pulse parameters And _a , And _b , And _c , And _g (And _x ), where
And _a : + A _a , -A _a , + S _a , -S _a , + t _a , -t _a , + N _a , -N _a ;
And _b : + A _b , -A _b , + S _b , -S _b , + t _b , -t _b , + N _b , -N _b ;
And _c : + A _c , -A _c , + S _c , -S _c , + t _c , -t _c , + N _c , -N _c ;
And _g : + A _g , -A _g , + S _g , -S _g , + t _g , -t _g , + N _g , -N _g ;
± A _a , ± A _b , ± A _c , ± A _g (± A _x ) - the maximum amplitude of pulses of positive and negative polarity in the current interval;
± t _a , ± t _b , ± t _c , ± t _g (± t _x ) is the integral duration of positive and negative pulses;
± S _a , ± S _b , ± S _c , ± S _g (± S _x ) is the integral area of positive and negative impulses;
± N _a , ± N _b , ± N _c , ± N _g (± N _x ) - the number of negative and positive pulses in the interval.

The device for measuring pulse parameters 3 (see Fig. 2) consists of four identical channels, the information inputs of which receive signals U _x and from the broadband outputs of the input device.

 The information inputs of the adder 31 and the counter 33 of positive signals and one of the inputs of the shaper 30 receives a signal from the output of the comparator 24 of the positive signals. The information inputs of the adder 32 and the counter 34 of negative signals and the other input of the driver 30 receives a signal from the output of the comparator 25 of the negative signals.

The control inputs of the peak detectors 26 and 27, integrators 28 and 29, counters 33 and 34, and adders 31 and 32 receive a reset signal R _x .

 The operation of the channel of the pulse parameter measuring device 3 is illustrated by the timing diagrams shown in FIG. 4a.

If U _{x and the} positive or negative threshold voltage is exceeded, the corresponding comparator 24 or 25 is activated, and the driver 30 generates a signal M _x , under the influence of which the signal UX changes in the output device 1, which allows, at an appropriate duration, to skip the low-frequency part of the pulse noise by conversion and control device input 4.

The measurement of the parameters U _{x and is} carried out periodically on the interval between the pulses of the corresponding signals R _x .

Using peak detectors 26 and 27, the maximum amplitude U _{x is recorded} , using integrators 28 and 29, the integral values of U _{x are recorded} , using adders 31 and 32, the total duration U _{x is fixed} in the measurement interval, and the number of pulses U _{x is} calculated using counters 33 and 34 . At the end of each measurement interval, the signals of the values of the impulse parameters And _x are fixed in the sampling and storage unit 12 of the conversion and control device 4, after which a new interval for the measurement of impulse parameters begins.

The signals I _x and U _x , as well as And _x , supplied to the narrow-band inputs of the conversion and control device 4, are converted into digital form and fed to the information input of the programmable signal processing unit 5.

The signals I _x and U _x are supplied to the inputs of the sampling and storage unit 11 (see Fig. 3), in addition, U _a , U _b and U _c are supplied to the inputs of the former 21.

The information inputs of the sampling and storage unit 12 receive signals from the output of the switch 15, the inputs of which receive signals U _x from the outputs of the pulse parameters of the device for measuring pulse parameters 3.

 From the outputs of the sampling and storage blocks 11 and 12, the signals are fed to the information inputs of the switches 13 and 14, respectively.

 From the outputs of the switches 13 and 14, the signals are fed to the information input of the ADC 16.

 From the output of the shaper 21, a 50 Hz signal is supplied to one of the inputs of the phase-frequency adjustment block of frequency 22, its other input receives a signal from the output "50 Hz" of the frequency grid generator 19. Using the phase-adjustment block of frequency 22, the frequency grid is strictly synchronized with the frequency of the network 50 Hz

с выхода инвертора 20 поступают соответственно на управляющие входы блоков выборки и хранения 11 и 12, коммутаторов 13-15, формирователь сигналов 23, высокочастотный генератор 18 и блок модификации кодов 17.From the output of the frequency grid generator 19, the frequency signals F ₀ , F ₁ ... F ₆ , as well as the signal

from the output of the inverter 20 are respectively received at the control inputs of the sampling and storage units 11 and 12, switches 13-15, a signal conditioner 23, a high-frequency generator 18, and a code modification unit 17.

 From the output of the high-frequency generator 18, the clock signal is fed to the control input of the ADC 16.

From the outputs of the signal shaper 23, the signals R _x arrive at the control inputs of the device for measuring pulse parameters 3.

 Timing diagrams explaining the operation of the conversion and control device 4 are shown in FIG. 4b and 4c.

Under the influence of each pulse F _{0, the} high-frequency generator 18 forms a series of 16 high-frequency pulses (≈ 6 MHz), under the influence of which the ADC 16 carries out a cycle of converting an analog signal into a serial digital code.

осуществляется поочередное подключение блоков выборки и хранения 11 и 12 к информационному входу АЦП 16 (см. фиг 4б). Под воздействием сигналов F₄ и

синхронно с коммутаторами 13 и 14 блоки выборки и хранения 11 и 12 осуществляют выборку и хранение сигналов I_x, U_x, а также выходных сигналов коммутатора 15.Under the influence of signals F ₁ , F ₂ , F _{3, the} switches 13 and 14 carry out the switching of signals from the blocks of the sample and storage 11 and 12 to the information input of the ADC 16. According to the signals F ₄ and

alternately connecting the sampling and storage blocks 11 and 12 to the information input of the ADC 16 (see Fig. 4b). Under the influence of signals F ₄ and

synchronously with the switches 13 and 14, the sampling and storage blocks 11 and 12 sample and store the signals I _x , U _x , as well as the output signals of the switch 15.

 As can be seen from the timing diagram in FIG. 4b, the switch 13 is operating while the fetch and storage unit 11 is in storage mode, and the fetch and storage unit 12 is in fetch mode. The switch 14 and the block sampling and storage 12 are in antiphase with the switch 13 and the block sampling and storage 11.

According to the timing diagram of FIG. 4b, the signals U _x and I _x are fed to the information input of the ADC 16 during each period of F ₄ , while the signals And _{x of} each channel are fed to the information input of the ADC 16 4 times less often (see Fig. 4c) with a frequency of F ₆ . This is due to the fact that there are only 8 signals I _x and U _x , and 32 signals And _x .

The signals And _x are fed to the inputs of the switch 15, which commutes them to the information inputs of the sampling and storage device 12 under the influence of signals F ₅ and F ₆ .

Under the influence of the signals F ₅ and F ₆ supplied to the inputs of the signal shaper 23, the signals R _x are generated, which arrive at the control inputs of the pulse parameter measuring device 3. The sequence of signals R _x is shown in the diagram of FIG. 4c.

The code modification block 17 of the conversion and control device 4 provides the input of information into the ADC code on the sequence of channel codes and the scale of the signals U _x . The ADC code is received at one of the inputs of the code modification block 17, the frequency F _{6 is} supplied from the frequency generator 19 to the second input, the signal M _x from the scaling output of the pulse parameter measuring device 3 is received at the third input, and a modified code is received at the output.

 From the output of the code modification block 17, information about the measured values is supplied to the programmable data processing unit 5, where the serial code is converted to parallel. In the programmable data processing unit 5, data is buffered (16384 words - the minimum size of the data buffer intended for processing). At the same time, the programmable data processing unit 5 performs calculations on the data from the previous accumulated buffer, and the calculation results are written to the first random access memory 6 via the interprocessor communication interface 7. Upon completion of the calculations, the programmable data processing unit 5 reports to the central processor 9 “Data ready” . After analyzing the message "Data is ready", the central processor 9 records the service information in the second random access memory 8 via the interprocessor communication interface 7 and sets the signal "Exchange", after which the service information of the second random access memory 8 becomes available to the programmed data processing unit 5, on the basis of which it is believed that the exchange is completed, and the information of the first random access memory 6 becomes available to the Central processor 9. Thus Braz, the CPU 9 become available results of processing of the next data buffer, which are reproduced on the display means, and stored in the archive can be transmitted over the communications link. Programmable data processing unit 5 continues to accumulate the next data buffer, and upon completion of accumulation, the process is repeated.

 The process described above occurs during the operating state of the analyzer. At the initial time, the serial code entering the programmable data processing unit 5 is lost. In order for the analyzer to go into operation, it is necessary to enter the command "start measurement" in the central processor 9 (the command is entered using the keyboard). After that, the central processor writes to the second random access memory 8 via the interprocessor exchange interface 7 a program containing a data processing algorithm, a type of connection of channels, the number of phases, transformation ratios, limits of the measured parameters, etc. and sets the "Exchange" signal.

The advantages of the claimed invention over the known technical solutions are as follows:
- the device continuously measures all indicators of the quality of electricity at the same time in all phases;
- the device not only measures the above indicators, but also is a counter of electrical energy, as well as a transient recorder;
- the device measures not only quality indicators for voltage, but also quality indicators for current, measures all power components, which is necessary to identify the source of deterioration of quality indicators.

Claims (2)

1. An electric energy quality analyzer containing an input device configured to normalize voltage signals and phase currents and phase currents of the network and ground wires of a network and to separate voltage signals into narrow and broadband pulse components, one of the information inputs of the input device is connected to the unit the power supply, to the inputs of which phase voltage signals are supplied, the analyzer also contains a programmable signal processing unit connected in series through the system bus alov, the interface of the interprocessor exchange, the central processor and the means of displaying information, characterized in that it includes two random access memory connected by bidirectional buses with an interface of the interprocessor communication, while the system buses are bi-directional, a conversion and control device and a pulse measurement device are also introduced parameters, the scaling outputs of which are intended for generating scale change signals on them, are connected to the control inputs the input device and the conversion and control device, and the outputs of the pulse parameters are connected to the corresponding inputs of the conversion and control device, the information output of which is connected to the input of the programmable signal processing unit, the other outputs of the conversion and control device are connected to the corresponding control
reset signal inputs for synchronizing a pulse parameter measuring device, the other inputs of which are connected to the broadband outputs of an input device for supplying narrow-band pulse component signals to the corresponding inputs of a conversion and control device containing three switches, a high-frequency generator, a frequency grid generator, an inverter, a shaper, configured to generate a signal with a network frequency from phase voltage signals, a phase adjustment device h astot, a signal shaper, configured to generate reset signals in response to signals with a network frequency for synchronizing a pulse parameter measuring device, an analog-to-digital converter designed to convert analog normalized signals of phase currents and voltages and ground wire to a serial code, code modification unit , intended for introducing into the serial code information about the sequence of broadband signals along the channels of the device for measuring pulse pairs meters and the scale of the signals of currents and voltages of phases and ground wire, and two sampling and storage devices designed to supply signals to the information inputs of the respective switches, through which the sampling and storage devices are connected to the information input of the analog-to-digital converter, the output of which is via the modification unit codes connected to the information input of the programmable signal processing unit, the driver is connected in series with the phase adjustment unit, the frequency grid generator and
a high-precision generator designed to supply a clock signal to the control input of an analog-to-digital converter, the inputs of one of the sampling and storage devices are connected to the narrow-band inputs of the conversion and control device, the information input of the second sampling and storage device is connected to the output of the third switch, the inputs of which are connected to the outputs of the pulse parameters of the device for measuring pulse parameters, the outputs of the frequency grid generator are connected to the corresponding control inputs to ommutators, one of the sampling and storage devices, to the shaper, the code modification block and the inverter, the inverter output is connected to the control input of the second sampling and storage device and to the other control input of the switch sampling and storage device corresponding to this device to ensure the operation of one sampling and storage device with the corresponding switch in antiphase to the second sampling and storage device with the corresponding switch, the input of the shaper is connected to the information inputs of the input devices, the outputs of the signal shaper are connected to the control inputs of the pulse parameter measuring device, the corresponding scaling output of which is connected to the corresponding input of the code modification block.  2. The analyzer of the quality of electric energy according to claim 1, characterized in that the device for measuring pulse parameters consists of four identical channels, while one channel contains comparators of positive and negative signals, peak detectors of positive and negative signals, integrators of positive and negative signals, shaper zoom signal, adders duration of positive and negative signals and counters of positive and negative signals, and information inputs pico detectors, integrators and comparators are respectively connected to the channel information input, intended for receiving signals from the broadband outputs of the input device, the control inputs of the peak detectors of positive and negative signals, integrators of positive and negative signals, adders of the duration of positive and negative signals and counters of positive and negative signals connected to the channel input, intended for the receipt of reset signals, information inputs sum the positive signal signal generator and counter and one of the inputs of the zoom signal shaper are connected to the output of the positive signal comparator, the information inputs of the adder and the negative scale signal generator and the other input of the zoom signal shaper are connected to the output of the negative signal comparator, outputs of the peak detectors of positive and negative signals, integrators positive and negative signals, adders duration of positive and negative signals, counters put lnyh and negative signals and the signal shaper zoom connected to respective outputs of pulse parameters of the pulse measurement device.

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