RU85670U1 - ELECTRIC ENERGY QUALITY ANALYZER - Google Patents

Abstract

An electric energy quality analyzer containing an analog-to-digital converter with an input, a galvanic isolation module, a wavelet conversion unit, a system bus, a memory block, an interface module, a signal processing unit, the analog-to-digital converter being connected by its output to the input of the galvanic isolation module, which its output is connected to the input of the wavelet transform block, and the wavelet transform block, memory block, interface module and signal processing block are connected to the system bus.

Description

Technical field

The utility model relates to measuring technique and can be used to monitor the quality of the released electric energy.

State of the art

A device is known (according to the patent of the Russian Federation No. 2339046), which implements a method of compressing values characterizing the waveforms of a monitored electric energy signal, including collecting data representing periods of the electric energy signal, decomposing the waveform into many components, covering many periods of the waveform, and separately compressing the values at least some components, spanning many periods, characterized in that the conversion of the measurements of each group includes a fast Fourier transform. To achieve this result, data is collected that represent the periods of the monitored signal, and the decomposition of the waveform of the electric energy signal into many components. Moreover, this set includes the entire spectrum of wave periods. Then, individual values are compressed and these values and corresponding ranges of their changes are saved.

The composition of the known device includes blocks that make measurements, determine the frequency of the network, determine the values of the parameters, determine the intervals of values, memory blocks and the Fourier transform block.

The disadvantages of the known technical solutions are low productivity and lack of accuracy in the analysis of the quality of electrical energy.

The purpose of the proposed utility model is to increase the productivity and accuracy of the analysis of the quality of electric energy.

This goal is achieved due to the fact that in the analyzer of the quality of electric energy containing an analog-to-digital converter with an input, a galvanic isolation module, a wavelet transform unit, a system bus, a memory unit, an interface module, a signal processing unit, the analog-to-digital converter is connected its output with the input of the galvanic isolation module, which is connected by its output to the input of the wavelet transform block, and the wavelet transform block, memory block, interface module, and processing block and signal connected to the system bus.

Brief Description of the Drawings

The utility model is illustrated in the drawing, which shows a schematic diagram of an analyzer of the quality of electrical energy.

Utility Model Disclosure

The drawing shows: a crystal oscillator 1, a signal processing unit 2, a memory unit 3, an output converter 4, an interface module 5, an input divider block 6, an analog-to-digital converter 7, a galvanic isolation module 8, a wavelet transform unit 9, a system bus 10 .

The main elements of the device are the analog-to-digital converter (hereinafter referred to as the ADC) 7, the wavelet transform unit 9, the signal processing unit 2, the memory unit 3, the interface module 5. All elements of the device can be placed in the housing (not shown in the figure). The housing can be made of various shapes. The housing may consist of a bottom, walls and a cover. Holes can be made in the housing, providing inputs to the corresponding units of the device to perform the necessary operations. Inside the housing there is a block of input dividers 6, ADC 7, a galvanic isolation module 8, a wavelet transform unit 9, a system bus 10, a crystal oscillator 1, a signal processing unit 2, a memory unit 3, an output converter 4, and an interface module 5.

The elements in the device are connected as follows, the input divider block 6 is connected to the ADC 7. The ADC 7 is connected to the galvanic isolation module 8. The galvanic isolation module 8 is connected to the wavelet transform unit 9. The wavelet transform unit 9 is connected to the system bus 10. К A crystal oscillator 1, a signal processing unit 2, an output converter 4 and a memory unit 3 are connected to the system bus. The output converter 4 is connected to the interface module 5. The output converter 4 and the interface module 5 can be Nena as one device. The connection of elements in the device can be carried out using wires.

Block input dividers 6 is a device for proportionally reducing DC or AC voltage to the required values. Block input dividers 6 may include elements of active or reactance.

An analog-to-digital converter (ADC) 7 is a device made in a standard way and designed to convert an input analog signal (voltage and / or current) into digital form.

The galvanic isolation module 8 is a standard device, made, for example, in the form of an optocoupler pair.

Wavelet transform block 9 (http://chaos.ssu.runnet.ru/kafedra/edu_work/textbook/khovanovs-01/node25.html, http://ufn.ru/ufn96/ufn96_11/Russian/r9611a.pdf) configured to calculate the corresponding input signals to the output signals needed by the user. In a particular case, the side of wavelet transform 9 decomposes the initial signal according to the basis functions obtained from a certain prototype (for example, the Gauss function and its derivatives, the MNAT or the Mexican hat, the Meander function, the Morlet function) can be taken as the basis function , sprains and time shifts. In the wavelet transform unit 9, information about the basis function can be entered.

The crystal oscillator 1 is a standard device that ensures the stability of the entire device.

The device may include a signal processing unit 2. The signal processing unit 2 is a unit that performs additional necessary signal processing, for example, averaging, finding the maximum and / or minimum value, or other transformations necessary for the user.

The memory unit 3 is a device consisting of memory cells in which the information necessary for the user is recorded.

The output converter 4 is a device designed to convert the signal received into it into the form necessary for the user, for example, converting the signal for further display or transmission of the signal.

Interface module 5, provides a graphical display and exchange of information between interacting objects. Interface module 5 may have an output, for example, RS-232, USB or Ethernet.

The system bus 10 is configured to connect it to a crystal oscillator 1, a wavelet transform unit 9, a signal processing unit 2, a memory unit 3 and an output converter 4. The system bus 10 is designed to transfer the necessary data between the elements of the device.

The device may include a block of logical integrated circuits (not shown in the figure), which is a microcircuit or a block of connected microcircuits, which are logical elements. The logic integrated circuit block may be connected to the system bus 10.

Utility Model Implementation

The utility model is implemented as follows. The device is designed to analyze the quality of electrical energy in the electrical network. An electric network is understood as a set of devices serving for the transmission and distribution of electrical energy to power consumers. To analyze the quality of electrical energy, the user connects the device to the electrical network. To do this, the user connects the corresponding inputs of the device with an electric circuit. In the particular case, when the device is connected to the electric network, the current / voltage signal in the electric network enters the ADC 7, which receives the analog input signals and converts them into digital signals suitable for processing by other elements of the device. To the block of input dividers 6 receives a signal about the voltage from the electrical network. The voltage generated by the block of input dividers 6 is reduced to allowed values. Next, the signal from the block of input dividers 6 goes to the corresponding input of the ADC 7. The ADC 7 receives the input analog signals about the voltage / current and converts them into digital signals suitable for further processing by the digital blocks of the device. Also, the signal about the current and voltage can be supplied directly to the ADC 7, when the device is executed without the output divider unit 6. Next, the signal from the ADC 7 goes to the corresponding input of the galvanic isolation module 8. The galvanic isolation module 8 protects the internal units of the device from damage during voltage surges online. Then, the signal from the galvanic isolation module 8 is supplied to the wavelet transform unit 10. The wavelet transform unit 10 converts the current and / or voltage signal into the corresponding matrix of wavelet transform coefficients in accordance with the selected basis function. For this, the wavelet transform unit 10 multiplies the received signal with the basis function in a specific time interval for a given time shift. The result of the multiplication is recorded in the cell matrix of the wavelet coefficients. Then the basis function is shifted in time and the scalar product is calculated again, the result of which is written in the next cell of the matrix. They increase the scale of the basic function and perform similar actions, thereby forming the next row of the matrix of wavelet coefficients. The result of the wavelet transform will be an N × M matrix, where N is the number of displacements of the basis function, and M is the number of scale changes. The results of the resulting matrix are the calculated amplitude and phase of each harmonic component (from the 1st to the nth). To assess the non-sinusoidality of the measured currents and voltages, knowledge of the phase is not required (this value is needed for other purposes), and the assessment is carried out using the following coefficients (for example, for voltage):

Sine Wave Distortion Factor

Coefficient of the n-th harmonic (interharmonic) component

Where U ₁ - the amplitude (or effective value) of the first harmonic;

U _n is the amplitude (or effective value) of the nth harmonic (interharmonics). Next, the wavelet transform unit 10 transmits a signal on the magnitude of the product of the basic function by the original signal to the system bus 10. From the system bus 10, the signal enters the corresponding blocks. In this case, the crystal oscillator 1 sets the clock frequency of the entire device for the timely operation of the corresponding blocks of the device.

The signal processing unit 2 carries out additional necessary signal processing, averages, and finds the maximum and / or minimum value. The converted signals are transmitted by the signal processing unit 2 to the system bus 10. From the system bus 10, the converted signal is transmitted to the output converter 4, which converts the signal for further transmission or display on the corresponding device.

The converted signals in the wavelet transform unit 9 and in the signal processing unit 2 are, if necessary, recorded in the corresponding memory cells of the memory unit 3.

Also, the signals from the wavelet transform unit 9 are sent via the system bus 10 to the output converter 4, where it is converted to the signal necessary for transmission through the interface module 5 for display or further transmission to other devices.

Thus, the goal is achieved due to the fact that in the device containing the ADC 7, the wavelet transform unit 9, the signal processing unit 2 and the interface module 5 with a combination of all the features of the device, the set increase in productivity and accuracy of the analysis of the quality of electric energy is achieved.

Claims (1)

An electric energy quality analyzer comprising an analog-to-digital converter with an input, a galvanic isolation module, a wavelet conversion unit, a system bus, a memory block, an interface module, a signal processing unit, the analog-to-digital converter being connected by its output to the input of the galvanic isolation module, which its output is connected to the input of the wavelet transform block, and the wavelet transform block, memory block, interface module and signal processing block are connected to the system bus.