Device for monitoring and diagnostics of electrical parameters of industrial equipment

Abstract

FIELD: industrial electronics.SUBSTANCE: invention relates to systems for monitoring and diagnosing electrical parameters of industrial equipment, such as frequency converters, servo amplifiers, power supplies, electric motors, generators and other electrical equipment. The device for monitoring and diagnosing electrical parameters of industrial equipment comprises m current channels and n voltage channels, where m and n≥ 1; analogue-to-digital converters (ADC); a signal processing processor, the output of which is connected to the communication interface. Each current channel comprises an input for current sensors. Each voltage channel includes: an input for connecting the measured voltages, a voltage divider, the output of which is connected to a low-pass filter, the output of which is connected to an isolation amplifier, the output of which is connected to the ADC. The isolation amplifiers are equipped with an isolated power supply, and the ADCs used are ADCs with simultaneous sampling and adjustable sampling frequency for each channel in the range of 50÷350 kHz. It is preferable that the Ethernet interface be used as the communication interface. It is preferable that remote current sensors that support high-frequency signal measurement in the range of 25-50 kHz, such as Hall sensors and / or transformer-type sensors, be used as current sensors.EFFECT: increased monitoring accuracy and information content; adaptation to various types of industrial equipment; analysis of high-speed processes; and improved electrical safety and noise immunity.2 cl, 1 dwg

Description

[0001] The invention relates to the field of industrial electronics, namely to systems for monitoring and diagnosing electrical parameters of industrial equipment, such as frequency converters, servo amplifiers, power supplies, electric motors, generators and other electrical equipment.

[0002] A current and voltage measuring device is known, comprising three bipolar electrical interconnections, each interconnection configured to be connected between two separate ends of high-voltage conductors; first and second current sensors configured and configured to measure the current through the first interconnection and through the third interconnection, respectively; and first and second voltage sensors configured and configured to measure the voltage between the first and second interconnections and between the second and third interconnections; the measurement of two current values ​​and two voltage values ​​is performed at a floating potential. This measuring unit can be installed directly on all three phases of a substation, for example, with its own internal power supply and without grounding. The actual measurements are performed between the phases.The current can be measured using a Hall sensor, a shunt sensor, a Rogowski coil current sensor, or a transformer, such as a nanocore current transformer. Voltage can be measured using a voltage divider. Based on its high accuracy, the device can perform both commercial energy metering and measuring / monitoring electrical parameters for technical purposes (e.g. power quality, voltage or current fluctuations) (patent EA 040726B1 for the invention "CURRENT AND VOLTAGE MEASURING UNIT", published on July 21, 2022, IPC G01R 15 / 14). The known device is intended for commercial energy metering and power quality control at substations of high-voltage electrical grids (3 ÷ 50 kV) and cannot be used for high-speed diagnostics and predictive maintenance of low-voltage (up to 1000 V) industrial equipment.

[0003] A device for monitoring the state of an electrical network and a power facility is known to be the closest in terms of the set of essential features to the claimed invention and has been selected as a prototype. The device contains current channels and voltage measurement channels, analog-to-digital converters, a signal processing processor, and a communication interface. The device comprises an event storage unit and an oscillogram storage unit, the outputs of which are connected to communication interfaces for transmitting data to the upper control level (RU Patent No. 2531038 for the invention "DEVICE FOR MONITORING THE STATE OF AN ELECTRIC NETWORK AND A POWER FACILITY", published on 20.10.2014, IPC G01R 19 / 00). The disadvantages of the known device are: insufficient accuracy and information content of monitoring industrial equipment with fixed parameters; difficulty of adaptation to various types of industrial equipment; impossibility of analyzing high-speed processes; insufficient electrical safety and noise immunity.

[0004] The task that the claimed technical solution is aimed at solving is the creation of an effective device for monitoring and diagnosing the electrical parameters of industrial equipment, which has improved technical characteristics.

[0005] The technical results achieved by solving the specified problem are:

[0006] - increasing the accuracy and information content of monitoring;

[0007] - ensuring the possibility of adaptation to various types of industrial equipment;

[0008] - providing the ability to analyze fast-moving processes;

[0009] - improving electrical safety and noise immunity.

[0010] The specified technical results are achieved by the fact that the device for monitoring and diagnosing the electrical parameters of industrial equipment contains m current channels and n voltage channels, where m and n ≥ 1; analog-to-digital converters (ADCs); a signal processing processor, the output of which is connected to the communication interface. Each current channel contains an input for current sensors. Each voltage channel includes: an input for connecting the measured voltages, a voltage divider, the output of which is connected to a low-pass filter, the output of which is connected to an isolation amplifier, the output of which is connected to the ADC. The isolation amplifiers are equipped with an isolated power source, and the ADCs used are ADCs with simultaneous sampling and an adjustable sampling frequency for each channel in the range of 50 ÷ 350 kHz.

[0011] It is preferable that the Ethernet interface be used as the communication interface.

[0012] It is preferable that the current sensors used be remote current sensors that support high-frequency signal measurement in the range of 25÷50 kHz, such as Hall sensors and / or transformer-type sensors.

[0013] The device may contain a memory unit for buffering and storing measured data and / or waveforms when the Ethernet network is unavailable.

[0014] The device can also be enclosed in a case.

[0015] A comparative analysis of the claimed invention with the prototype showed that in all cases of execution it differs from the known, closest technical solution:

[0016] - the implementation of each current channel containing an input for current sensors;

[0017] - the implementation of each voltage channel, including an input for connecting the measured voltages, a voltage divider, the output of which is connected to a low-pass filter, the output of which is connected to an isolating amplifier, the output of which is connected to the ADC;

[0018] - implementation of isolation amplifiers, equipped with an isolated power source;

[0019] - using an ADC with simultaneous sampling and adjustable sampling frequency for each channel in the range of 50÷350 kHz.

[0020] A comparative analysis of the claimed invention with the prototype showed that in certain cases of execution it differs from the known, closest technical solution:

[0021] - using Ethernet interface as the communication interface;

[0022] - using external current sensors as current sensors that support high-frequency signal measurement in the range of 25÷50 kHz, for example, Hall sensors and / or transformer-type sensors;

[0023] - the execution of the device enclosed in a housing;

[0024] - the presence of a memory block for buffering and storing measured data and / or oscillograms when the Ethernet network is unavailable.

[0025] The implementation of a current channel containing an input for current sensors allows the use of various types of remote sensors, including those supporting high-frequency signal measurement in the range of 25÷50 kHz, for example, Hall sensors and / or transformer type, which expands the functionality of the device.

[0026] Each voltage measurement channel includes an input for connecting the measured voltages, a voltage divider whose output is connected to a low-pass filter, the output of which is connected to an isolation amplifier, the output of which is connected to a signal processing processor via analog-to-digital converters. This design enhances the electrical safety, noise immunity, and noise immunity of the device. The voltage divider scales the measured voltage to a level compatible with the input levels of subsequent units. The low-pass filter performs input filtering, suppresses high-frequency interference, and provides anti-aliasing filtering. The isolation amplifier provides galvanic isolation of the measurement circuits from the processing circuits, enhancing electrical safety.

[0027] Using an ADC with simultaneous sampling and a configurable sampling rate for each channel (voltage measurements) in the range of 50–350 kHz improves measurement accuracy by enabling simultaneous, high-frequency sampling of multiple input voltages and currents with interference protection and subsequent analysis of the collected data for predictive diagnostics. The configurable sampling rate enables the analysis of fast-moving processes, allowing you to select the optimal operating mode depending on the task: for example, 50 or 100 kHz for typical measurements, up to 350 kHz for analyzing fast-moving processes.

[0028] Using the Ethernet interface as a communication interface ensures rapid information exchange and the possibility of integration into industrial automation systems.

[0029] The presence of a memory block allows data and waveforms to be buffered when the network is temporarily unavailable, ensuring the safety of information.

[0030] The device is housed in a housing, providing a compact and protected design suitable for installation in industrial automation cabinets.

[0031] All of this allows for adaptation to various types of industrial equipment, enabling comprehensive monitoring of complex objects, such as a complete frequency converter with a DC bus; it improves the accuracy and information content of monitoring, enhances the electrical safety of the device, reduces the impact of interference, and enables integration into automation and diagnostic systems.

[0032] The proposed invention is illustrated by a schematic drawing shown in Figure 1.

[0033] Fig. 1 shows a structural block diagram of the claimed device for monitoring and diagnosing electrical parameters of industrial equipment.

[0034] In a preferred embodiment, the device for monitoring and diagnosing electrical parameters of industrial equipment comprises m current channels 1, where m = 1...i, and n voltage channels 2, where n =1...j; analog-to-digital converters (ADC) 3; a signal processing processor 4, the output of which is connected to a communication interface 5. Each current channel 1 contains an input 6 for connecting current sensors 7. Each voltage channel 2 includes an input 8 for connecting measured voltages, a voltage divider 9, the output of which is connected to a low-pass filter 10, the output of which is connected to an isolating amplifier 11, the output of which is connected to an ADC 3. Isolating amplifiers 11 are equipped with an isolated power source 12, and an ADC with simultaneous sampling and an adjustable sampling frequency for each channel in the range of 50÷350 kHz is used as an ADC 3.

[0035] It is preferable that the Ethernet interface be used as communication interface 5.

[0036] It is preferable that the current sensors 7 be remote current sensors that support high-frequency signal measurement in the range of 25÷50 kHz, for example, Hall sensors and / or transformer-type sensors.

[0037] Analog-to-digital converters 3 may be implemented, for example, in the form of two multichannel ADC chips 3-1, 3-2 with simultaneous sampling (e.g., two 8-channel chips), connected to processor 4 via a serial interface. Separate chip selection and conversion start signals are used for each ADC 3-1, 3-2, ensuring sampling synchronization. The device may include a memory unit 13 for buffering and storing measured data and / or oscillograms when the Ethernet network is unavailable. The device may also be enclosed in a housing 14.

[0038] The device operates as follows.

[0039] The device is mounted inside the control cabinet of industrial equipment, and the device can be enclosed in housing 14.

[0040] The measuring wires from the corresponding points of the industrial equipment control object 15 are connected to the 8 voltage inputs of channels 2: input phases and neutral (if there is a neutral conductor) or phase pairs (if there is no neutral for performing interphase measurements), as well as connection points to the DC+ and DC− DC bus and / or output phases of the frequency converter (depending on the configuration of the equipment being controlled).

[0041] Remote current sensors 7, installed on the corresponding conductors (for example, detachable Hall sensors and / or transformer type, made in the form of a ring / clamps), are connected to the inputs of 6 current channels 1.

[0042] The measured voltages, arriving at input 8 of voltage channel 2, are fed to voltage dividers 9, which scale the measured voltage to a level compatible with the input levels of subsequent units. In one embodiment, voltage divider 9 is high-impedance, for example, with a total resistance of approximately 1 MΩ (specifically, approximately 1.05 MΩ), which reduces the device's impact on the measured circuit and limits the current in the input circuit.

[0043] From the outputs of voltage dividers 9, the signal is fed to low-pass filters 10, which perform input filtering and high-frequency interference suppression, as well as anti-aliasing filtering. The signal is then fed to isolation amplifiers 11, which provide galvanic isolation of the measuring circuits from the processing circuits and improve the electrical safety and noise immunity of the device. Power for isolation amplifiers 11 is provided by isolated power source 12 (e.g., an isolated DC / DC converter). In one embodiment, amplifiers of the AMC1200 type can be used as isolation amplifiers 11, and an E0515S-1WR3 DC / DC converter can be used as isolated power source 12.

[0044] The output signals of the isolation amplifiers 11 are fed to the analog-to-digital converters 3. The signals from the current sensors 7, connected to the inputs 6 of the current channels 1, are also fed to the analog-to-digital converters 3, which are capable of simultaneous sampling by channels and with a configurable sampling frequency for each channel in the range of 50 ÷ 350 kHz. The ADCs 3 can be implemented as two multi-channel ADC chips with simultaneous sampling, with one ADC chip used primarily for the voltage channels, and the other primarily for the current channels, or the distribution of channels between the chips is specified during the design of the device.

[0045] Signal processor 4 synchronously collects digital data from ADC 3, generates ADC 3 control signals (including conversion trigger and chip selection signals), and sets sampling modes. The sampling frequencies of voltage channels 1 and current channels 2 can be set independently. For example, a sampling frequency of 200 kHz can be set for voltage channels, and 50 kHz for current channels. This is achieved by skipping individual conversion triggers corresponding to ADC 3 while maintaining synchronization during shared triggers for analyzing related processes.

[0046] Processor 4 performs digital processing of measured data, including, for example: scaling and calibration, calculation of effective values ​​(Urms, Irms), calculation of active and reactive power, spectral analysis and calculation of spectral features, evaluation of DC bus pulsations (e.g., at a frequency of 300 Hz), calculation of voltage and current crest factors, determination of current angles, estimation of DC link capacitor capacitance based on current and pulsation response, as well as other diagnostic indicators. Processor 4 can perform event detection based on threshold conditions and / or calculated features and generate oscillograms (including those with pre- and post-trigger sections).

[0047] For data storage and buffering, the device may include memory block 13, which stores measurement data and / or oscillograms, even during temporary network unavailability. With sufficient memory, data can be stored for extended periods (e.g., up to a month).

[0048] Data is transmitted to external monitoring system 16 via communication interface 5, preferably Ethernet. If communication is available, transmission can be in the form of observation packets and / or periodic oscillogram transmission. If communication is lost, data is temporarily buffered in memory unit 13 for subsequent transmission once the connection is restored.

[0049] The number of m current channels 1 and n voltage channels 2 depends on the number of measured parameters and industrial equipment being diagnosed.

[0050] Implementation example.

[0051] The device is installed in an industrial cabinet and connected to a frequency converter: three input phases, a neutral DC bus (DC+ and DC−), and three output phases of the frequency converter—up to nine voltage points in total. Six remote current sensors 7 are also connected, mounted on the corresponding wires (input and output phases). The device simultaneously measures all parameters at a specified sampling rate and transmits the data to an external monitoring system 16 for analysis and diagnostics.

[0052] LIST OF STRUCTURAL ELEMENTS

[0053] 1. current channels (quantity - m, where m=1…i);

[0054] 2. voltage channels (number - n, where n =1…j);

[0055] 3. ADC;

[0056] 4. signal processing processor;

[0057] 5. communication interface;

[0058] 6. Input for current sensors;

[0059] 7. Remote current sensors;

[0060] 8. Input for connecting measured voltages;

[0061] 9. voltage divider;

[0062] 10. Low pass filter;

[0063] 11. Isolation amplifier;

[0064] 12. Isolated power supply;

[0065] 13. memory block;

[0066] 14. device body;

[0067] 15. Industrial equipment control objects

[0068] external monitoring system.

Claims

1. A device for monitoring and diagnosing electrical parameters of industrial equipment, comprising m current channels and n voltage channels, where m and n ≥ 1; analog-to-digital converters (ADCs); a signal processing processor, the output of which is connected to a communication interface, characterized in that each current channel includes an input for connecting current sensors; each voltage channel includes an input for connecting measured voltages, a voltage divider, the output of which is connected to a low-pass filter, the output of which is connected to an isolation amplifier, the output of which is connected to the ADC, wherein the isolation amplifiers are provided with an isolated power source, and the ADCs used are ADCs with simultaneous sampling and an adjustable sampling frequency for each channel in the range of 50÷350 kHz.

2. The device according to paragraph 1, characterized in that an Ethernet interface is used as the communication interface.

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