GIS transient overvoltage multi-measuring-point synchronous online monitoring method and system

Abstract

The invention discloses a GIS (Gas Insulated Switchgear) transient overvoltage multi-measuring-point synchronous online monitoring method and system. The method comprises the following steps: selecting a trigger mode for performing overvoltage monitoring on a plurality of measuring points of a GIS; obtaining a trigger condition corresponding to the trigger mode and a current monitoring signal, and judging whether the monitoring signal meets the trigger condition or not; when it is judged that the monitoring signal meets the triggering condition, a synchronization signal is sent to each collection unit in the multiple measurement points through a synchronization unit; and acquiring a voltage signal based on the received synchronizing signal through each acquisition unit in the plurality of measuring points, storing the voltage signal, and monitoring the transient overvoltage of the GIS through the stored voltage signal.

Description

Technical Field

[0001] The present invention relates to the technical field of online monitoring of transient electrical parameters of electrical equipment, and more specifically, to a method and system for synchronous online monitoring of transient overvoltage at multiple measuring points in a GIS. Background Art

[0002] In ultra-high voltage / ultra-high voltage projects, gas insulated switchgear (GIS) has become a key component of the power system with its significant advantages such as compact layout, small size, high reliability, strong safety and environmental friendliness. The types of overvoltage in the power system are divided into internal and external overvoltage. External overvoltage usually refers to atmospheric overvoltage, which has a steep wave head and high amplitude. It is one of the main causes of insulation accidents in power systems; the amplitude of internal overvoltage is generally not very high, but its duration is long, which also poses a serious threat to the insulation of electrical equipment. In particular, when the disconnector or circuit breaker inside the GIS is operated, a very fast transient overvoltage (VFTO) will be generated. VFTO is a type of internal overvoltage in the power system. Its high-frequency component is usually in the range of several MHz to hundreds of MHz, the rise time is usually in the nanosecond level, the amplitude is between 1.5 and 2.5pu, and in rare cases it may even exceed 3.0pu. Extremely high overvoltage amplitude and frequency will threaten the insulation of winding equipment (transformers, high-voltage reactors and PTs) directly connected to GIS, causing extremely uneven voltage distribution between turns or between disks of windings, leading to insulation breakdown; it will also seriously interfere with the normal operation of secondary equipment. And as the voltage level of the transmission line increases, the insulation margin of the equipment will decrease, and the harm caused by VFTO to UHV equipment will be greater.

[0003] Therefore, it is particularly necessary to conduct online transient overvoltage monitoring of GIS equipment, which can not only effectively prevent damage to GIS and its connected winding equipment and secondary equipment due to overvoltage, improve system stability and power supply reliability, but also provide real-time data support for fault diagnosis and preventive maintenance, ensuring the safe, economical and efficient operation of the power system. Summary of the invention

[0004] The technical solution of the present invention provides a method and system for synchronous online monitoring of multiple measuring points of transient overvoltage in GIS, so as to solve the problem of how to synchronously monitor multiple measuring points of transient overvoltage in GIS online.

[0005] In order to solve the above problems, the present invention provides a method for synchronous online monitoring of transient overvoltage at multiple measuring points in GIS, the method comprising:

[0006] Select the trigger mode for overvoltage monitoring of multiple measuring points of gas-insulated switchgear GIS;

[0007] Acquire a trigger condition corresponding to the trigger mode and a current monitoring signal, and determine whether the monitoring signal meets the trigger condition;

[0008] When it is determined that the monitoring signal meets the trigger condition, a synchronization signal is sent to each acquisition unit in the multiple measuring points through the synchronization unit;

[0009] Each acquisition unit in the multiple measuring points acquires a voltage signal based on the received synchronization signal, stores the voltage signal, and monitors the transient overvoltage of the gas insulated switchgear GIS through the stored voltage signal.

[0010] Preferably, the trigger modes include: instruction trigger mode, internal synchronization trigger mode and external synchronization trigger mode.

[0011] Preferably, when the selected trigger mode is the instruction trigger mode, sending an instruction to the synchronization unit;

[0012] After receiving the instruction, the synchronization unit sends a synchronization signal to each acquisition unit in the multiple measuring points.

[0013] Preferably, when the selected trigger mode is the external synchronization trigger mode, the synchronization unit receives the monitoring signal using an antenna, and when the received signal amplitude is greater than a set first amplitude threshold, it is determined that the monitoring signal meets the trigger condition.

[0014] Preferably, when the selected trigger mode is the internal synchronization trigger mode, the trigger conditions include amplitude trigger and change rate trigger;

[0015] When the trigger condition is selected as an amplitude trigger, the amplitude of the monitoring signal collected by each collection unit in the multiple measuring points is compared with the set second amplitude threshold, and when it is determined that the amplitude of the monitoring signal is greater than the set second amplitude threshold, it is determined that the monitoring signal meets the trigger condition; or

[0016] When the trigger condition is selected as the change rate trigger, the change rate of the monitoring signal collected by each acquisition unit in the multiple measuring points is compared with the set change rate threshold. When it is determined that the change rate of the monitoring signal is greater than the set change rate threshold, it is determined that the monitoring signal meets the trigger condition.

[0017] Preferably, the acquisition unit includes a high-speed signal conditioning module, a high-speed AD chip, an FPGA, a memory, a first optical fiber module and a second optical fiber module;

[0018] The collected signal of the collection unit is input into the high-speed AD chip after being processed by the high-speed signal conditioning module, and the collected voltage signal is converted into a digital signal by the high-speed AD chip and then input into the FPGA;

[0019] The FPGA is connected to the first optical fiber module and the second optical fiber module; the first optical fiber module is connected to the router via optical fiber; the second optical fiber module is connected to the synchronization unit via optical fiber;

[0020] The FPGA is connected to the memory, and the collected signals are stored in the memory.

[0021] Preferably, a preamplifier is arranged before the high-speed signal conditioning module of the acquisition unit, and the preamplifier includes an overvoltage protection circuit composed of a gas discharge tube and a varistor network to provide overvoltage protection for the high-speed signal conditioning module.

[0022] Preferably, the synchronization unit and the acquisition unit are powered by corresponding power supply units respectively;

[0023] The power supply unit includes three stages, each of which is separately arranged in a shielded shell; the first stage sends the external 220V AC voltage to the second stage after passing through a surge protection circuit and a filtering network; the second stage uses an isolation transformer, a filtering network, and a TVS tube to protect the abnormal voltage of the power supply unit and then sends it to the third stage; the third stage uses an ACDC module to convert the AC voltage into a 12V DC power supply.

[0024] Based on another aspect of the present invention, the present invention provides a GIS transient overvoltage multi-measurement point synchronous online monitoring system, the system comprising:

[0025] An initialization unit for selecting a triggering mode for overvoltage monitoring of multiple measuring points of a gas-insulated switchgear GIS;

[0026] An acquisition unit, used to acquire a trigger condition corresponding to the trigger mode and a current monitoring signal, and determine whether the monitoring signal satisfies the trigger condition;

[0027] A sending unit, configured to send a synchronization signal to each acquisition unit in a plurality of measuring points through a synchronization unit when it is determined that the monitoring signal meets a trigger condition;

[0028] The result unit is used to collect voltage signals based on the received synchronization signals through each collection unit in multiple measuring points, store the voltage signals, and monitor the transient overvoltage of the gas insulated switchgear GIS through the stored voltage signals.

[0029] Preferably, the trigger modes include: instruction trigger mode, internal synchronization trigger mode and external synchronization trigger mode.

[0030] Preferably, when the selected trigger mode is the instruction trigger mode, sending an instruction to the synchronization unit;

[0031] After receiving the instruction, the synchronization unit sends a synchronization signal to each acquisition unit in the multiple measuring points.

[0032] Preferably, when the selected trigger mode is the external synchronization trigger mode, the synchronization unit receives the monitoring signal using an antenna, and when the received signal amplitude is greater than a set first amplitude threshold, it is determined that the monitoring signal meets the trigger condition.

[0033] Preferably, when the selected trigger mode is the internal synchronization trigger mode, the trigger conditions include amplitude trigger and change rate trigger;

[0034] When the trigger condition is selected as an amplitude trigger, the amplitude of the monitoring signal collected by each collection unit in the multiple measuring points is compared with the set second amplitude threshold, and when it is determined that the amplitude of the monitoring signal is greater than the set second amplitude threshold, it is determined that the monitoring signal meets the trigger condition; or

[0035] When the trigger condition is selected as the change rate trigger, the change rate of the monitoring signal collected by each acquisition unit in the multiple measuring points is compared with the set change rate threshold. When it is determined that the change rate of the monitoring signal is greater than the set change rate threshold, it is determined that the monitoring signal meets the trigger condition.

[0036] Preferably, the acquisition unit includes a high-speed signal conditioning module, a high-speed AD chip, an FPGA, a memory, a first optical fiber module and a second optical fiber module;

[0037] The collected signal of the collection unit is input into the high-speed AD chip after being processed by the high-speed signal conditioning module, and the collected voltage signal is converted into a digital signal by the high-speed AD chip and then input into the FPGA;

[0038] The FPGA is connected to the first optical fiber module and the second optical fiber module; the first optical fiber module is connected to the router via optical fiber; the second optical fiber module is connected to the synchronization unit via optical fiber;

[0039] The FPGA is connected to the memory, and the collected signals are stored in the memory.

[0040] Preferably, a preamplifier is arranged before the high-speed signal conditioning module of the acquisition unit, and the preamplifier includes an overvoltage protection circuit composed of a gas discharge tube and a varistor network to provide overvoltage protection for the high-speed signal conditioning module.

[0041] Preferably, the synchronization unit and the acquisition unit are powered by corresponding power supply units respectively;

[0042] The power supply unit includes three stages, each of which is separately arranged in a shielded shell; the first stage sends the external 220V AC voltage to the second stage after passing through a surge protection circuit and a filtering network; the second stage uses an isolation transformer, a filtering network, and a TVS tube to protect the abnormal voltage of the power supply unit and then sends it to the third stage; the third stage uses an ACDC module to convert the AC voltage into a 12V DC power supply.

[0043] Based on another aspect of the present invention, the present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and the computer program is used to execute a GIS transient overvoltage multi-measurement point synchronous online monitoring method.

[0044] Based on another aspect of the present invention, the present invention provides an electronic device, characterized in that the electronic device comprises: a processor and a memory; wherein,

[0045] The memory is a memory for storing instructions executable by the processor;

[0046] The processor is used to read the executable instructions from the memory and execute the instructions to implement a GIS transient overvoltage multi-measurement point synchronous online monitoring method.

[0047] The technical solution of the present invention provides a method and system for synchronous online monitoring of transient overvoltage at multiple measuring points of GIS, wherein the method includes: selecting a trigger mode for overvoltage monitoring at multiple measuring points of gas insulated switchgear GIS; obtaining the trigger condition corresponding to the trigger mode and the current monitoring signal, and judging whether the monitoring signal meets the trigger condition; when judging that the monitoring signal meets the trigger condition, sending a synchronization signal to each acquisition unit in the multiple measuring points through the synchronization unit; collecting the voltage signal based on the received synchronization signal through each acquisition unit in the multiple measuring points, and storing the voltage signal, and monitoring the transient overvoltage of the gas insulated switchgear GIS through the stored voltage signal. The technical solution of the present invention provides a method and system for long-term real-time online monitoring of transient overvoltage of all types with multiple trigger modes and capable of realizing synchronization of multiple measuring points, which has three trigger modes of internal synchronization triggering, external synchronization triggering, and instruction triggering, and can quickly and sensitively capture the occurrence of transient overvoltage. The technical solution of the present invention can realize synchronous monitoring of multiple measuring points. The technical solution of the present invention can monitor the transient overvoltage phenomenon caused by lightning strikes or other operations in the power system in real time, thereby preventing and reducing the damage to the power equipment, and improving the safety and reliability of the power grid operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0049] Figure 1 A flowchart of a method for synchronous online monitoring of transient overvoltage at multiple measuring points in GIS according to a preferred embodiment of the present invention;

[0050] Figure 2 A schematic diagram of the overall architecture of an online monitoring system according to a preferred embodiment of the present invention;

[0051] Figure 3 A schematic diagram of the principle of a collection unit according to a preferred embodiment of the present invention;

[0052] Figure 4 A schematic diagram of a pre-amplifier circuit of a collection unit according to a preferred embodiment of the present invention;

[0053] Figure 5 A schematic diagram of a PGA amplifier circuit according to a preferred embodiment of the present invention;

[0054] Figure 6 An AD conversion circuit diagram according to a preferred embodiment of the present invention;

[0055] Figure 7 A circuit diagram of an SFP optical fiber interface of a collection terminal according to a preferred embodiment of the present invention;

[0056] Figure 8 A schematic diagram of a synchronization unit according to a preferred embodiment of the present invention;

[0057] Fig. 9 A schematic diagram of a synchronization unit SFP optical fiber interface circuit 1 according to a preferred embodiment of the present invention;

[0058] Fig.10 A schematic diagram of a synchronization unit SFP optical fiber interface circuit 2 according to a preferred embodiment of the present invention;

[0059] Fig.11 A schematic diagram of an external synchronous trigger signal identification circuit according to a preferred embodiment of the present invention;

[0060] Fig.12 This is a schematic diagram of the power supply principle from AC 220V to DC 12V according to a preferred embodiment of the present invention;

[0061] Fig.13 A schematic diagram of a battery charging and switching circuit according to a preferred embodiment of the present invention;

[0062] Fig.14 A schematic diagram of an internal synchronization trigger program design according to a preferred embodiment of the present invention;

[0063] Fig.15 A flowchart of a multi-point synchronization program according to a preferred embodiment of the present invention; and

[0064] Fig.16 The structure diagram of a GIS transient overvoltage multi-measurement point synchronous online monitoring system according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0065] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0066] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0067] Figure 1 The present invention is a flowchart of a method for synchronous online monitoring of transient overvoltage at multiple measuring points in GIS according to a preferred embodiment of the present invention.

[0068] The transient overvoltage online monitoring system needs to monitor the two electrical signals with large frequency differences, external and internal overvoltages of the power system, at the same time. It needs both a high sampling frequency and a large signal storage depth. Considering that multiple measuring points are usually set up on the GIS during field testing, in order to ensure the synchronization of data collection at each measuring point and facilitate comparison and analysis of subsequent data processing, it is necessary to use multi-point synchronous triggering technology during the measurement process. In addition, in order to accurately monitor various types of transient overvoltages, it is necessary to fully consider the typical waveform characteristics of various types of transient overvoltage signals to design the trigger mode and trigger program logic more comprehensively. At the same time, the complex electromagnetic environment interference at the substation site makes the electromagnetic shielding and power supply unit design of the online monitoring system face higher technical requirements.

[0069] Therefore, the present invention aims at the online monitoring of various types of transient overvoltages (especially VFTO) that may occur during the operation of ultra-high voltage GIS equipment. The actual application conditions and requirements are further considered, and a method and system for long-term real-time online monitoring of all types of transient overvoltages with multiple triggering modes and capable of achieving multi-point synchronization are designed from aspects such as triggering mode design and multi-point synchronous monitoring. The method and system provided by the present invention have three triggering modes: internal synchronous triggering, external synchronous triggering, and instruction triggering, which can quickly and sensitively capture the occurrence of transient overvoltages. The present invention can achieve synchronization of 6 measuring points and can further expand the number of measuring points.

[0070] The present invention proposes a multi-trigger mode GIS transient overvoltage multi-point synchronous online monitoring system and method, which includes a collection unit, a synchronization unit, a switch unit, a host computer and a power supply unit. The overall system architecture is shown in FIG. Figure 2 .

[0071] When working, the present invention continuously samples the signal through the acquisition unit, analyzes the signal at the same time, determines whether the trigger condition is met, and starts to store the data if the trigger condition is met. At the same time, the trigger synchronization signal is output to the synchronization unit through the optical fiber. After the synchronization unit receives the trigger signal, it outputs the synchronization trigger signal to each acquisition unit through the optical fiber, so as to realize the synchronous acquisition of all acquisition units at each measuring point. This trigger acquisition mode is an internal synchronous trigger.

[0072] The antenna of the synchronization unit of the present invention receives an external electromagnetic signal, judges the signal, and generates a trigger signal when a trigger condition is met, so that all the acquisition units synchronously acquire data, thereby realizing external synchronous triggering.

[0073] The acquisition units of the present invention are connected to the router via optical fiber, the host computer sends instructions to each acquisition unit via the router, the data collected by each acquisition unit is transmitted to the router via optical fiber, and then forwarded to the host computer by the router.

[0074] The present invention provides a method for synchronous online monitoring of transient overvoltage at multiple measuring points in GIS, the method comprising:

[0075] Step 101: selecting a trigger mode for overvoltage monitoring of multiple measuring points of a gas insulated switchgear GIS;

[0076] Preferably, the trigger modes include: a command trigger mode, an internal synchronization trigger mode and an external synchronization trigger mode.

[0077] Step 102: Acquire the trigger condition corresponding to the trigger mode and the current monitoring signal, and determine whether the monitoring signal meets the trigger condition;

[0078] Preferably, when the selected trigger mode is the instruction trigger mode, sending instructions to the synchronization unit;

[0079] After receiving the instruction, the synchronization unit sends a synchronization signal to each acquisition unit in the multiple measuring points.

[0080] Preferably, when the selected trigger mode is the external synchronization trigger mode, the monitoring signal is received by the synchronization unit using an antenna, and when the received signal amplitude is greater than a set first amplitude threshold, it is determined that the monitoring signal meets the trigger condition.

[0081] Preferably, when the selected trigger mode is the internal synchronization trigger mode, the trigger conditions include amplitude trigger and change rate trigger;

[0082] When the trigger condition is selected as an amplitude trigger, the amplitude of the monitoring signal collected by each collection unit in the multiple measuring points is compared with the set second amplitude threshold, and when it is determined that the amplitude of the monitoring signal is greater than the set second amplitude threshold, it is determined that the monitoring signal meets the trigger condition; or

[0083] When the trigger condition is selected as the change rate trigger, the change rate of the monitoring signal collected by each acquisition unit in the multiple measuring points is compared with the set change rate threshold. When it is determined that the change rate of the monitoring signal is greater than the set change rate threshold, it is determined that the monitoring signal meets the trigger condition.

[0084] Step 103: When it is determined that the monitoring signal meets the trigger condition, a synchronization signal is sent to each acquisition unit in the multiple measuring points through the synchronization unit;

[0085] Step 104: each acquisition unit in the multiple measuring points acquires a voltage signal based on the received synchronization signal, stores the voltage signal, and monitors the transient overvoltage of the gas insulated switchgear GIS through the stored voltage signal.

[0086] Preferably, the acquisition unit includes a high-speed signal conditioning module, a high-speed AD chip, an FPGA, a memory, a first optical fiber module, and a second optical fiber module;

[0087] The collected signal of the collection unit is input into the high-speed AD chip after being processed by the high-speed signal conditioning module. The collected voltage signal is converted into a digital signal by the high-speed AD chip and then input into the FPGA.

[0088] The FPGA is connected to the first optical fiber module and the second optical fiber module; the first optical fiber module is connected to the router via optical fiber; the second optical fiber module is connected to the synchronization unit via optical fiber;

[0089] The FPGA is connected to the memory, and the collected signals are stored in the memory.

[0090] Preferably, a preamplifier is arranged before the high-speed signal conditioning module of the acquisition unit, and the preamplifier includes an overvoltage protection circuit composed of a gas discharge tube and a varistor network to provide overvoltage protection for the high-speed signal conditioning module.

[0091] Preferably, the synchronization unit and the acquisition unit are powered by corresponding power supply units respectively;

[0092] The power supply unit consists of three levels, each of which is separately arranged in a shielded shell; the first level sends the external 220V AC voltage to the second level after passing through a surge protection circuit and a filter network; the second level uses an isolation transformer, a filter network, and a TVS tube to protect the power supply unit from abnormal voltage and then sends it to the third level; the third level uses an ACDC module to convert the AC voltage into a 12V DC power supply.

[0093] The principle diagram of the acquisition unit of the present invention is as follows Figure 3 As shown. Its working principle is that the high-speed signal (amplitude ±5V, maximum frequency 100MHz) is converted into a ±1V signal after high-speed signal conditioning to meet the requirements of the high-speed AD chip ZGAD250S14. The analog signal is converted into a digital signal through the ZGAD250S14 high-speed AD and enters the FPGA through the LVDS interface. The acquisition unit has two optical fiber modules, the first of which is connected to the router for command reception and data upload. The second optical fiber module is connected to the synchronization unit for output and reception of trigger signals. In the internal synchronization trigger working mode, each acquisition unit analyzes and judges the collected data. If the trigger condition is met, it starts to record the data and outputs the synchronization pulse to the synchronization unit. After receiving the synchronization signal, the synchronization unit forwards this signal to each acquisition unit to achieve synchronous acquisition among the six acquisition units. In the external synchronization trigger mode, the FPGA receives the synchronization signal sent by the synchronization unit to achieve synchronous acquisition of the six acquisition units.

[0094] The high-speed AD chip ZGAD250S14 of the present invention is a 14-bit, single-channel high-speed ADC with a maximum sampling rate of 250Msps and a signal-to-noise ratio of up to 65dB, which can meet the requirements of the system's high-speed signal sampling rate and accuracy. FPGA uses Xilinx's Artix7 series FPGA, and the XC7A100T has a maximum operating frequency of up to 1G, which can meet the requirements of the high-speed AD interface rate. At the same time, FPGA writes the sampled data into the DDR3 memory to achieve real-time storage of the data, and saves the data of the 50mS before and after the event into the DDR memory when the trigger condition is met. In actual application, the storage capacity of 1G can store the data of 500M sampling points, that is, it can store 2 seconds of data under the sampling rate state of 250MS / s. On the other hand, the sampling rate can be set by the host computer at different sampling rates according to the specific application environment.

[0095] The preamplifier circuit of the acquisition unit of the present invention is as follows Figure 4 As shown in the figure, in order to meet the requirement of high input impedance, the preamplifier of the signal conditioning circuit is designed. In the figure, the input bias current of OPA817 is 2pA, which can meet the requirement of 20M ohm input impedance. At the same time, an overvoltage protection circuit consisting of a gas discharge tube and a varistor network is added to the input end to realize overvoltage protection of the signal conditioning circuit.

[0096] The PGA amplifier circuit of the present invention is as follows Figure 5 As shown in the figure, the signal output by the preamplifier is adjusted in amplitude by the PGA composed of AD8307, and then driven differentially by LMH6551 before entering the AD chip for AD conversion.

[0097] The AD conversion circuit of the present invention is as follows Figure 6 As shown, the AD chip uses the high-speed AD chip ZGAD250S14 produced by ZGA Semiconductor with a sampling rate of 250Msps and a resolution of 14 bits.

[0098] The SFP optical fiber interface circuit of the acquisition terminal of the present invention is as follows Figure 7 As shown, the acquisition unit has two SFP fiber optic interfaces and uses a TL-SM411SSA 2.5G fiber optic transmission module with a transmission rate of up to 2.5Gbps.

[0099] The principle diagram of the synchronization unit of the present invention is as follows Figure 8 As shown. The synchronization unit and the acquisition unit cooperate to realize the synchronization trigger function. In the internal synchronization trigger working mode, each acquisition unit analyzes the signal to determine whether the trigger condition is met. When the trigger condition is met, the trigger signal is output to the FPGA of the synchronization unit through the optical fiber. After the FPGA recognizes this signal, it sends a trigger signal to the six acquisition units at the same time, realizing the function of all acquisition units collecting data when any acquisition unit detects an abnormality.

[0100] In the external synchronous trigger working mode of the present invention, the synchronization unit filters and amplifies the overvoltage electromagnetic wave signal received by the antenna and sends it to the comparator. At the same time, the FPGA outputs different voltages to the comparator through the DA to set the threshold of the comparator. When the received signal amplitude is greater than the threshold, the comparator outputs a pulse signal to the FPGA, the synchronization unit identifies the external overvoltage signal, outputs a synchronization signal to each acquisition unit, triggers each acquisition unit to start recording data, and realizes the external synchronous trigger function.

[0101] Since the synchronization unit needs to be connected to the acquisition unit, it receives the synchronization signal of the acquisition module, generates a system synchronization signal after logical judgment, and sends it to each acquisition module to realize the synchronous acquisition of the module. The synchronization error is required to be less than 1us, so the transmission rate is required to be very high. In order to meet the requirements of technical indicators, the SFP optical fiber interface is used to realize the communication between the acquisition unit and the synchronization unit. The synchronization unit optical fiber interface circuit is as follows Fig. 9 , Fig.10 As shown in the figure, units 1 to 6 are used to connect to the acquisition unit, and unit 7 is used to connect to the router.

[0102] The external synchronous trigger signal recognition circuit of the present invention is as follows Fig.11As shown. In the figure, the signal input from the antenna interface P1D is filtered by a 50M~100M bandpass filter and then sent to the logarithmic detection amplifier for amplification and then sent to the comparator IC4D. The signal IC5 output by the FPGA is converted into a variable voltage, and then amplified by IC6D and sent to the comparator as the reference voltage of the comparator. The output signal of the comparator is sent to the FPGA for identifying the external synchronous trigger signal.

[0103] The acquisition unit and synchronization unit of the online monitoring system of the present invention are powered separately by their own power supply units. The working mode of the power supply unit is to alternately use 220V AC power supply and battery backup power supply. In order to ensure the battery power supply time, the system adopts the automatic switching mode of the backup battery. When the 220V power supply has power, the 220V power supply supplies power to each module of the system on the one hand, and charges the battery on the other hand. When the 220V power supply loses power, it automatically switches to battery power supply, and the battery power supply time is 4 hours.

[0104] The AC 220V to DC 12V power supply principle diagram of the present invention is as follows Fig.12 As shown. The entire architecture is divided into three levels, and each part is installed separately in a shielded shell. The external 220V AC voltage of the first level is sent to the second level after passing through the surge protection circuit and the filter network. The second level uses an isolation transformer, a filter network, and a TVS tube to protect the abnormal voltage of the power supply before sending it to the third level. In the third level, the ACDC module is used to convert the AC voltage into a 12V DC power supply to power the battery management and power switching circuits.

[0105] The battery management and switching circuit of the present invention is as follows Fig.13 As shown. In the figure, a battery management chip is used to charge the battery, and a MOS tube is used to switch the battery. When the 12V power supply voltage is powered, Q2C and Q6C are turned off, Q1C is turned on, and the external 12V power supply voltage supplies power to the acquisition terminal or synchronization unit; when the 12V power supply loses power, Q2C and Q6C are turned on, Q1C is turned off, and the battery supplies power to the acquisition unit or synchronization unit.

[0106] The acquisition unit of the present invention is designed with multi-trigger mode programs, and the trigger mode selection module outputs a control signal according to the instruction from the host computer, so that the three trigger modes of instruction triggering, external synchronous triggering and internal synchronous triggering are respectively effective.

[0107] When the trigger mode is selected as command trigger, the host computer directly sends a command to the synchronization unit. After the synchronization unit receives the command that needs to be triggered synchronously, it outputs 6 synchronous trigger signals to 6 acquisition units through optical fibers, and each acquisition unit performs voltage waveform acquisition and recording operations. The command trigger mode can meet the needs of scenarios such as system debugging and verification.

[0108] When the trigger mode is selected as external synchronous trigger, the synchronization unit uses the antenna to receive the overvoltage electromagnetic wave signal. When the received signal amplitude is greater than the set threshold, the comparator outputs a pulse signal to the FPGA. The synchronization unit identifies the external overvoltage signal and outputs a synchronization signal to each acquisition unit, triggering each acquisition unit to start recording data.

[0109] When the trigger mode is selected as internal synchronous trigger, the trigger program design principle is as follows Fig.14 As shown. The trigger program is selected through the host computer. When the amplitude trigger is selected, the data collected by the AD is compared with the amplitude threshold sent by the host computer. If it is greater than the threshold, a trigger instruction is generated and sent to the synchronization unit; when the change rate trigger is selected, the change rate of the data collected by the AD is calculated and compared with the change rate threshold sent by the host computer. If it is greater than the threshold, the trigger instruction is sent to the synchronization unit. After receiving the trigger instruction, the synchronization unit will output a storage instruction to start the storage control module, retain the data 50mS before the trigger moment, and start writing the newly collected data to the DDR memory until 200mS data is written.

[0110] The multi-point synchronization program design block diagram of the present invention is as follows Fig.15 As shown, the left side is the internal synchronization program flow of the acquisition unit, and the right side is the internal signal processing flow of the synchronization unit.

[0111] In the acquisition unit, the duty cycle of the PWM module output signal is 20% when not triggered, and the duty cycle of the PWM module output signal is 80% when triggered. The pulse width modulation signal drives the optical fiber module to output the optical signal, which is sent to the synchronization unit through the optical fiber.

[0112] In the synchronization unit, the optical fiber module sends the received signal to the duty cycle detection module, and determines whether the trigger signal is received based on the detection result. Each trigger condition detection is sent to the trigger condition merging module, which generates a synchronization signal after performing logical judgment on the trigger signals of the six acquisition units. This synchronization signal is sent to the synchronization mode selection module, and the host computer controls the module to select external synchronization mode or internal synchronization mode.

[0113] The signal output by the synchronization mode selection module controls the duty cycle output by the PWM unit. The duty cycle signal is then sent to the 6-channel fiber optic module. The 6 fiber optic modules simultaneously output duty cycle change signals to each acquisition unit. The acquisition unit detects the duty cycle of the signal received by the optical fiber and can identify the trigger signal, thereby completing the synchronization of all acquisition units.

[0114] The present invention provides a long-term real-time online monitoring system for all types of transient overvoltages with multiple triggering modes and capable of realizing synchronization of multiple measuring points. The monitoring system has three triggering modes: internal synchronous triggering, external synchronous triggering, and command triggering, which can quickly and sensitively capture the occurrence of transient overvoltages; the monitoring system can realize synchronization of 6 measuring points, and the number of measuring points can be further expanded. The bandwidth of the online monitoring system can cover 10Hz~100MHz, and the amplitude-frequency response fluctuation is less than ±1dB within the measurement frequency range. Its advantages are: ① The triggering mode is diverse, with three triggering modes: command triggering, internal synchronous triggering, and external synchronous triggering. The trigger program logic can select amplitude triggering or rate of change triggering; ② It has the function of synchronous online monitoring of multiple measuring points, and the synchronization error is less than 1us, which can meet the needs of synchronous monitoring of multiple measuring points in practical applications.

[0115] The transient overvoltage online monitoring system proposed in the present invention has a multi-measurement-point synchronous online monitoring function.

[0116] The specific performance is as follows: Figure 2 and attached Figure 8 , the synchronization unit and the acquisition unit cooperate to realize the multi-measurement point synchronization trigger function. In the internal synchronization trigger working mode, each acquisition unit analyzes the signal to determine whether it meets the trigger condition. When the trigger condition is met, the trigger signal is output to the FPGA of the synchronization unit through the optical fiber. After the FPGA recognizes this signal, it sends a trigger signal to 6 acquisition units at the same time, realizing the function of all acquisition units collecting data when any acquisition unit detects an abnormality. In the external synchronization trigger working mode, the synchronization unit filters and amplifies the signal received by the antenna and sends it to the comparator. At the same time, the FPGA outputs different voltages to the comparator through DA to set the threshold of the comparator. When the amplitude of the received signal is greater than the threshold, the comparator outputs a pulse signal to the FPGA, the synchronization unit identifies the external transient overvoltage, outputs a synchronization signal to each acquisition unit, and triggers each acquisition unit to start recording data. Realize the external synchronization function.

[0117] The transient overvoltage online monitoring system proposed in the present invention has multiple triggering modes, and the triggering program logic can independently select amplitude triggering or change rate triggering.

[0118] Specifically, the trigger mode selection module outputs control signals according to the instructions from the host computer, making the instruction trigger, internal synchronization trigger, and external synchronization trigger effective. For the selection of trigger program logic, refer to the attached Fig.14 The host computer can independently choose to trigger according to the amplitude of the collected voltage waveform or the rate of change of the voltage waveform, which can avoid missed collection due to different characteristics of various transient overvoltage waveforms, and can accurately monitor all types of transient overvoltage situations that may occur in GIS equipment during operation.

[0119] The application of the transient overvoltage online monitoring method proposed in the present invention is very important in the power system, especially in the operation and management of ultra-high voltage GIS substations. This monitoring technology can monitor the transient overvoltage phenomenon caused by lightning strikes or other operations in the power system in real time, thereby preventing and reducing damage to power equipment and improving the safety and reliability of power grid operation.

[0120] Fig.16 The structure diagram of a GIS transient overvoltage multi-measurement point synchronous online monitoring system according to a preferred embodiment of the present invention.

[0121] like Fig.16 As shown, the present invention provides a GIS transient overvoltage multi-measurement point synchronous online monitoring system, the system includes:

[0122] Initial unit 1601, used for selecting a trigger mode for overvoltage monitoring of multiple measuring points of a gas insulated switchgear GIS;

[0123] Preferably, the trigger modes include: a command trigger mode, an internal synchronization trigger mode and an external synchronization trigger mode.

[0124] The acquisition unit 1602 is used to acquire the trigger condition corresponding to the trigger mode and the current monitoring signal, and determine whether the monitoring signal meets the trigger condition;

[0125] Preferably, when the selected trigger mode is the instruction trigger mode, sending instructions to the synchronization unit;

[0126] After receiving the instruction, the synchronization unit sends a synchronization signal to each acquisition unit in the multiple measuring points.

[0127] Preferably, when the selected trigger mode is the external synchronization trigger mode, the monitoring signal is received by the synchronization unit using an antenna, and when the received signal amplitude is greater than a set first amplitude threshold, it is determined that the monitoring signal meets the trigger condition.

[0128] Preferably, when the selected trigger mode is the internal synchronization trigger mode, the trigger conditions include amplitude trigger and change rate trigger;

[0129] When the trigger condition is selected as an amplitude trigger, the amplitude of the monitoring signal collected by each collection unit in the multiple measuring points is compared with the set second amplitude threshold, and when it is determined that the amplitude of the monitoring signal is greater than the set second amplitude threshold, it is determined that the monitoring signal meets the trigger condition; or

[0130] When the trigger condition is selected as the change rate trigger, the change rate of the monitoring signal collected by each acquisition unit in the multiple measuring points is compared with the set change rate threshold. When it is determined that the change rate of the monitoring signal is greater than the set change rate threshold, it is determined that the monitoring signal meets the trigger condition.

[0131] The sending unit 1603 is used to send a synchronization signal to each acquisition unit in the multiple measuring points through the synchronization unit when it is determined that the monitoring signal meets the trigger condition;

[0132] The result unit 1604 is used to collect voltage signals based on the received synchronization signal through each collection unit in the multiple measuring points, store the voltage signals, and monitor the transient overvoltage of the gas insulated switchgear GIS through the stored voltage signals.

[0133] Preferably, the acquisition unit includes a high-speed signal conditioning module, a high-speed AD chip, an FPGA, a memory, a first optical fiber module, and a second optical fiber module;

[0134] The collected signal of the collection unit is input into the high-speed AD chip after being processed by the high-speed signal conditioning module. The collected voltage signal is converted into a digital signal by the high-speed AD chip and then input into the FPGA.

[0135] The FPGA is connected to the first optical fiber module and the second optical fiber module; the first optical fiber module is connected to the router via optical fiber; the second optical fiber module is connected to the synchronization unit via optical fiber;

[0136] The FPGA is connected to the memory, and the collected signals are stored in the memory.

[0137] Preferably, a preamplifier is arranged before the high-speed signal conditioning module of the acquisition unit, and the preamplifier includes an overvoltage protection circuit composed of a gas discharge tube and a varistor network to provide overvoltage protection for the high-speed signal conditioning module.

[0138] Preferably, the synchronization unit and the acquisition unit are powered by corresponding power supply units respectively;

[0139] The power supply unit consists of three levels, each of which is separately arranged in a shielded shell; the first level sends the external 220V AC voltage to the second level after passing through a surge protection circuit and a filter network; the second level uses an isolation transformer, a filter network, and a TVS tube to protect the power supply unit from abnormal voltage and then sends it to the third level; the third level uses an ACDC module to convert the AC voltage into a 12V DC power supply.

[0140] The present invention provides a computer-readable storage medium, which stores a computer program for executing a GIS transient overvoltage multi-measurement point synchronous online monitoring method.

[0141] The present invention provides an electronic device, the electronic device comprising: a processor and a memory; wherein:

[0142] Memory, a memory for storing processor executable instructions;

[0143] The processor is used for reading executable instructions from the memory and executing the instructions to realize a method for synchronous online monitoring of multiple measuring points of transient overvoltage in GIS.

[0144] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0145] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0146] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0147] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0148] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0149] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0150] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0151] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of said means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A method for synchronous online monitoring of transient overvoltage at multiple measuring points in GIS, the method comprising: Select the trigger mode for overvoltage monitoring of multiple measuring points of gas-insulated switchgear GIS; Acquire a trigger condition corresponding to the trigger mode and a current monitoring signal, and determine whether the monitoring signal meets the trigger condition; When it is determined that the monitoring signal meets the trigger condition, a synchronization signal is sent to each acquisition unit in the multiple measuring points through the synchronization unit; Each acquisition unit in the multiple measuring points acquires a voltage signal based on the received synchronization signal, stores the voltage signal, and monitors the transient overvoltage of the gas insulated switchgear GIS through the stored voltage signal.

2. The method according to claim 1, wherein the trigger mode comprises: Command trigger mode, internal synchronization trigger mode and external synchronization trigger mode.

3. The method according to claim 2, when the selected trigger mode is the instruction trigger mode, sending an instruction to the synchronization unit; After receiving the instruction, the synchronization unit sends a synchronization signal to each acquisition unit in the multiple measuring points.

4. According to the method described in claim 2, when the selected trigger mode is the external synchronization trigger mode, the monitoring signal is received by the synchronization unit using an antenna, and when the received signal amplitude is greater than a set first amplitude threshold, it is determined that the monitoring signal meets the trigger condition.

5. The method according to claim 2, when the selected trigger mode is the internal synchronization trigger mode, the trigger conditions include amplitude trigger and change rate trigger; When the trigger condition is selected as an amplitude trigger, the amplitude of the monitoring signal collected by each collection unit in the multiple measuring points is compared with the set second amplitude threshold, and when it is determined that the amplitude of the monitoring signal is greater than the set second amplitude threshold, it is determined that the monitoring signal meets the trigger condition; or When the trigger condition is selected as the change rate trigger, the change rate of the monitoring signal collected by each acquisition unit in the multiple measuring points is compared with the set change rate threshold. When it is determined that the change rate of the monitoring signal is greater than the set change rate threshold, it is determined that the monitoring signal meets the trigger condition.

6. The method according to claim 1, wherein the acquisition unit comprises a high-speed signal conditioning module, a high-speed AD chip, an FPGA, a memory, a first optical fiber module, and a second optical fiber module; The collected signal of the collection unit is input into the high-speed AD chip after being processed by the high-speed signal conditioning module, and the collected voltage signal is converted into a digital signal by the high-speed AD chip and then input into the FPGA; The FPGA is connected to the first optical fiber module and the second optical fiber module; the first optical fiber module is connected to the router via optical fiber; the second optical fiber module is connected to the synchronization unit via optical fiber; The FPGA is connected to the memory, and the collected signals are stored in the memory.

7. According to the method of claim 6, a pre-amplifier is arranged in front of the high-speed signal conditioning module of the acquisition unit, and the pre-amplifier includes an overvoltage protection circuit composed of a gas discharge tube and a varistor network to provide overvoltage protection for the high-speed signal conditioning module.

8. The method according to claim 1, wherein the synchronization unit and the acquisition unit are powered by corresponding power supply units respectively; The power supply unit includes three stages, each of which is separately arranged in a shielded shell; the first stage sends the external 220V AC voltage to the second stage after passing through a surge protection circuit and a filtering network; the second stage uses an isolation transformer, a filtering network, and a TVS tube to protect the abnormal voltage of the power supply unit and then sends it to the third stage; the third stage uses an ACDC module to convert the AC voltage into a 12V DC power supply.

9. A GIS transient overvoltage multi-point synchronous online monitoring system, the system comprising: An initialization unit for selecting a triggering mode for overvoltage monitoring of multiple measuring points of a gas-insulated switchgear GIS; An acquisition unit, used to acquire a trigger condition corresponding to the trigger mode and a current monitoring signal, and determine whether the monitoring signal satisfies the trigger condition; A sending unit, configured to send a synchronization signal to each acquisition unit in a plurality of measuring points through a synchronization unit when it is determined that the monitoring signal meets a trigger condition; The result unit is used to collect voltage signals based on the received synchronization signals through each collection unit in multiple measuring points, store the voltage signals, and monitor the transient overvoltage of the gas insulated switchgear GIS through the stored voltage signals.

10. The system according to claim 9, wherein the trigger mode comprises: Command trigger mode, internal synchronization trigger mode and external synchronization trigger mode.

11. The system according to claim 10, when the selected trigger mode is the instruction trigger mode, sending instructions to the synchronization unit; After receiving the instruction, the synchronization unit sends a synchronization signal to each acquisition unit in the multiple measuring points.

12. According to the system of claim 10, when the selected trigger mode is the external synchronization trigger mode, the monitoring signal is received by the synchronization unit using an antenna, and when the received signal amplitude is greater than a set first amplitude threshold, it is determined that the monitoring signal meets the trigger condition.

13. The system according to claim 10, when the selected trigger mode is the internal synchronization trigger mode, the trigger conditions include amplitude trigger and change rate trigger; When the trigger condition is selected as an amplitude trigger, the amplitude of the monitoring signal collected by each collection unit in the multiple measuring points is compared with the set second amplitude threshold, and when it is determined that the amplitude of the monitoring signal is greater than the set second amplitude threshold, it is determined that the monitoring signal meets the trigger condition; or When the trigger condition is selected as the change rate trigger, the change rate of the monitoring signal collected by each acquisition unit in the multiple measuring points is compared with the set change rate threshold. When it is determined that the change rate of the monitoring signal is greater than the set change rate threshold, it is determined that the monitoring signal meets the trigger condition.

14. The system according to claim 9, wherein the acquisition unit comprises a high-speed signal conditioning module, a high-speed AD chip, an FPGA, a memory, a first optical fiber module, and a second optical fiber module; The collected signal of the collection unit is input into the high-speed AD chip after being processed by the high-speed signal conditioning module, and the collected voltage signal is converted into a digital signal by the high-speed AD chip and then input into the FPGA; The FPGA is connected to the first optical fiber module and the second optical fiber module; the first optical fiber module is connected to the router via optical fiber; the second optical fiber module is connected to the synchronization unit via optical fiber; The FPGA is connected to the memory, and the collected signals are stored in the memory.

15. According to the system of claim 14, a pre-amplifier is arranged in front of the high-speed signal conditioning module of the acquisition unit, and the pre-amplifier includes an overvoltage protection circuit composed of a gas discharge tube and a varistor network to provide overvoltage protection for the high-speed signal conditioning module.

16. The system according to claim 9, wherein the synchronization unit and the acquisition unit are powered by corresponding power supply units respectively; The power supply unit includes three stages, each of which is separately arranged in a shielded shell; the first stage sends the external 220V AC voltage to the second stage after passing through a surge protection circuit and a filtering network; the second stage uses an isolation transformer, a filtering network, and a TVS tube to protect the abnormal voltage of the power supply unit and then sends it to the third stage; the third stage uses an ACDC module to convert the AC voltage into a 12V DC power supply.

17. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 8.

18. An electronic device, characterized in that: The electronic device comprises: a processor and a memory; wherein, The memory is a memory for storing instructions executable by the processor; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method according to any one of claims 1 to 8.

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