A signal acquisition device for high voltage circuit breaker testing

Abstract

The present invention relates to a signal acquisition device for high-voltage circuit breaker testing, belonging to the technical field of high-voltage switch testing, the device comprises a signal acquisition cabinet, the cabinet body of the acquisition cabinet is made of metal material, a break signal acquisition board, a closing signal acquisition board, an opening signal acquisition board and a travel signal acquisition board are arranged in the acquisition cabinet, and the components used for measuring various signals of the high-voltage circuit breaker are integrated into respective signal acquisition boards to form a signal acquisition module; wherein, the input end of the break signal acquisition module is connected in parallel to the two ends of the main contact break of the high-voltage circuit breaker, the input end of the opening / closing signal acquisition module is connected in series to the control power supply circuit of the opening / closing coil of the circuit breaker, and the input end of the travel signal acquisition module is used to connect the travel sensor fixed to the circuit breaker. The present invention is simple in structure and easy to operate, can avoid being affected by the high-voltage circuit breaker test to the greatest extent, protect the equipment from damage, thereby improving the test efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of high-voltage switch testing, and in particular relates to a signal acquisition device for high-voltage circuit breaker testing. Background Art

[0002] High-voltage circuit breakers are important protection and control equipment in power systems. They are used as insulation and arc extinguishing devices, and are of great significance to the safe and stable operation of the system. The opening / closing time of high-voltage circuit breakers is an important indicator to measure the state of circuit breakers, and is also a set of parameters that must be measured in circuit breaker capacity tests. The closing time is from the moment of receiving the closing command to the moment of contact of all pole contacts, and the opening time is from the moment of receiving the opening command to the moment of separation of all pole contacts. According to the provisions of "GB1984-2018 High Voltage AC Circuit Breakers", the mechanical characteristics of the circuit breaker should be established before the capacity test, that is, the no-load test. Parameters such as the opening / closing time and travel curve obtained from the no-load test are used as reference mechanical characteristics to characterize the mechanical performance of the circuit breaker. The reference mechanical characteristics obtained from the no-load test are in a stable state, which is a necessary condition for successfully passing the capacity test, and is also a prerequisite for the test personnel to adjust the timing control and determine the arcing time. During the capacity test, the opening and closing time and the travel characteristic curve should also be measured for comparison and verification with the reference mechanical characteristics, and the arcing time can be accurately obtained at the same time.

[0003] At present, the main factors affecting the efficiency of high-voltage circuit breaker capacity testing and accurate product evaluation are the no-load test before the capacity test and the accurate acquisition of circuit breaker opening and closing time, travel curve and other related parameters during the capacity test. However, when various laboratories at home and abroad are faced with various products, due to the different sizes of opening / closing coil resistances and different travel sensors of various products, the opening and closing current range is large, and each laboratory basically builds signal acquisition devices temporarily, and various sensors are scattered in the power cabinet and the test room. When the setting position of the sensor and other signal acquisition devices is close to a high-voltage circuit breaker, the high voltage circuit breaker generates high voltage, high current and strong magnetic field during the live test, which is easy to damage these test equipment, resulting in economic losses, and greatly affecting the test efficiency, and also creating safety hazards. Summary of the invention

[0004] The object of the present invention is to provide a signal acquisition device for high-voltage circuit breaker testing, which is used to solve the problem that the existing device is easily affected by the high-voltage circuit breaker test, thereby causing damage to the equipment and low test efficiency.

[0005] Based on the above purpose, a technical solution of a signal acquisition device for high-voltage circuit breaker testing is as follows:

[0006] It includes a signal acquisition cabinet, the cabinet body of which is made of a metal material for shielding a magnetic field, and a break signal acquisition board, a closing signal acquisition board, an opening signal acquisition board and a travel signal acquisition board are arranged in the acquisition cabinet, and the components used for measuring the break signal, closing signal, opening signal and travel signal of the high-voltage circuit breaker are integrated into the respective signal acquisition boards to form a break signal acquisition module, a closing signal acquisition module, an opening signal acquisition module and a travel signal acquisition module; each acquisition module is connected to a front-end module of a data acquisition system through a cable, and then the front-end module is connected to a host of the data acquisition system through an optical fiber;

[0007] The input end of the break signal acquisition module is used to be connected in parallel to the two ends of the main contact break of the high-voltage circuit breaker, the input end of the closing signal acquisition module is used to be connected in series to the control power supply circuit of the circuit breaker closing coil, the input end of the opening signal acquisition module is used to be connected in series to the control power supply circuit of the circuit breaker opening coil, and the input end of the travel signal acquisition module is used to connect to the travel sensor fixed on the circuit breaker.

[0008] The beneficial effects of the above technical solution are:

[0009] The present invention proposes a modular signal acquisition device, that is, the components involved in the four signals to be detected in the circuit breaker test are integrated into their respective signal acquisition modules, and all signal acquisition modules are uniformly installed in a collection cabinet that can shield the magnetic field, which can avoid being affected by the high-voltage circuit breaker test to the greatest extent, protect the equipment from damage, and thus improve the test efficiency. The signal acquisition device of the present invention is simple in structure, easy to operate, safe and reliable, can meet the pressure test requirements of high-voltage circuit breakers, and has high market application value.

[0010] Furthermore, in order to avoid the problems of virtual connection of the connection line and the connection line being too long, the signal acquisition device also includes a workstation terminal block, one port of the workstation terminal block is connected to the input end of each signal acquisition module, and the other port of the workstation terminal block is used to connect the two ends of the main contact break of the high-voltage circuit breaker, the control power supply circuit of the closing coil, the control power supply circuit of the opening coil, and the travel sensor on the circuit breaker.

[0011] Furthermore, in order to solve the power supply problem of the acquisition device, a power module is installed in the signal acquisition cabinet, and the power module supplies power to each signal acquisition board respectively, so as to provide working power for each signal acquisition module.

[0012] Furthermore, since the power supply requirements of each signal acquisition module are different, in order to solve this problem, the power supply module is a rectifier converter, which obtains a suitable power supply voltage through rectification and conversion to power each signal acquisition module.

[0013] Furthermore, since the main contacts of the circuit breaker will generate high voltage when it is tested, a photoelectric coupler is integrated on the break signal acquisition board. The primary side of the photoelectric coupler is used to connect the main contact break of the high-voltage circuit breaker, and the secondary side of the photoelectric coupler is used to output the break signal for electrical isolation of the signal to protect the equipment from damage.

[0014] Furthermore, in order to realize the collection of closing signals during circuit breaker testing, the closing signal collection board is integrated with a current Hall element and an integrating amplifier. The collection end of the current Hall element is used to connect to the control power supply circuit of the circuit breaker closing coil, and the output end of the current Hall element is connected to the integrating amplifier, which is used to output the closing signal.

[0015] Furthermore, in order to realize the collection of the opening signal during the circuit breaker test, the opening signal collection board is integrated with a current Hall element and an integrating amplifier. The collection end of the current Hall element is used to connect to the control power supply circuit of the circuit breaker opening coil, and the output end of the current Hall element is connected to the integrating amplifier, which is used to output the opening signal.

[0016] Furthermore, after the no-load test using the signal acquisition device is completed and before the capacity test is performed, the connection line between the break signal acquisition module and the main contact of the high-voltage circuit breaker is disconnected to prevent the break signal acquisition module from being damaged during the capacity test. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a signal acquisition device in an embodiment of the present invention;

[0018] Figure 2 This is a wiring schematic diagram of a signal acquisition device during a no-load test in an embodiment of the present invention;

[0019] Figure 3 It is an oscillogram of the opening and closing, fracture and travel curves of a no-load operated circuit breaker in an embodiment of the present invention;

[0020] Figure 4 is a capacity test principle diagram in an embodiment of the present invention;

[0021] Figure 5 It is a wiring schematic diagram of a signal acquisition device during a capacity test in an embodiment of the present invention;

[0022] Figure 6 It is an oscillogram of the time, closing and travel curves of the circuit breaker breaking test in the embodiment of the present invention;

[0023] Figure 4 The labels in are explained as follows:

[0024] PT, short-circuit transformer; MB, protection circuit breaker; MS, closing switch; CB, operating circuit breaker; AB, auxiliary switch; TO, test piece; ZN, vacuum switch; L, inductance; R, resistance; C, capacitance; U, voltage measurement; I, current measurement; TA, Rogowski coil; TV1, resistor-capacitor voltage divider; Gap1, Gap2, ignition ball; Gap3, protection ball gap. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0026] This embodiment proposes a signal acquisition device for high-voltage circuit breaker testing, including a signal acquisition cabinet, in which a break signal acquisition board, a closing signal acquisition board, an opening signal acquisition board and a travel signal acquisition board are arranged. The components used to measure a certain signal of the high-voltage circuit breaker are integrated into their respective signal acquisition boards, and the four signal acquisition boards are arranged separately and independently without affecting each other.

[0027] like Figure 1 The signal acquisition cabinet shown in the figure is made of metal material, such as iron, steel or alloy material, to shield the external magnetic field and avoid damage to the equipment in the cabinet. Four acquisition modules are installed in the cabinet, and the four acquisition modules are composed as follows:

[0028] (I) Fracture signal acquisition module

[0029] The components used to measure the fracture signal, such as the photoelectric coupler, are integrated into the fracture signal acquisition board to form a fracture signal acquisition module; the acquisition module realizes the acquisition of the fracture signal mainly through the photoelectric coupler set on the acquisition board, the primary side of the photoelectric coupler is used to connect the main contact fracture of the high-voltage circuit breaker, and the secondary side of the photoelectric coupler is used to output the fracture signal. The photoelectric coupler is used to electrically isolate the collected fracture signal. At the same time, other peripheral circuits, such as filtering circuits, are also integrated on the acquisition board.

[0030] (II) Closing signal acquisition module

[0031] The components used to measure the closing signal of the high-voltage circuit breaker, such as the current Hall element and the integral amplifier, are integrated into the closing signal acquisition board to form a closing signal acquisition module. Among them, the acquisition end of the current Hall element is used to connect the control power supply circuit of the closing coil of the circuit breaker to detect the current in the control power supply circuit of the closing coil of the circuit breaker, and the output end of the current Hall element is connected to the integral amplifier to condition the received current into a closing signal of suitable amplitude.

[0032] (III) Opening signal acquisition module

[0033] The components used to measure the opening signal, such as the current Hall element and the integrating amplifier, are integrated into the opening signal acquisition board to form the opening signal acquisition module. Among them, the acquisition end of the current Hall element is used to connect the control power supply circuit of the circuit breaker opening coil to detect the current in the control power supply circuit of the circuit breaker opening coil, and the output end of the current Hall element is connected to the integrating amplifier to condition the received current into a suitable amplitude of the opening signal.

[0034] (IV) Travel signal acquisition module

[0035] Similar to the break signal acquisition module, the components used to measure the travel signal of the high-voltage circuit breaker, such as the photoelectric coupler, are integrated into the travel signal acquisition board to form a travel signal acquisition module. In this embodiment, the components concentrated on the travel signal acquisition board do not include the travel sensor, because the travel sensor is fixed on the circuit breaker.

[0036] Figure 1 The signal acquisition cabinet shown is also equipped with a power supply module for supplying power to each acquisition module, and providing a working power supply of corresponding voltage for the break signal acquisition module, the closing signal acquisition module, the opening signal acquisition module, and the travel signal acquisition module. The power supply module in this embodiment is a rectifier converter (AC-DC), which converts 220V AC into ±12V, ±5V DC power after voltage conversion, for example, providing 5V DC for the break signal acquisition module and 12V DC for the travel signal acquisition module.

[0037] In actual layout, the signal acquisition cabinet is fixed at an appropriate position in the laboratory, and is connected to the test station terminal block in the laboratory using a double-shielded cable, and the circuit breaker is connected through the terminal block. The specific connection relationship is as follows: Figure 2 As shown, the input end of the fracture acquisition module is connected in parallel to the two ends of the main contact fracture of the high-voltage circuit breaker through the station terminal block, and the output end of the fracture acquisition module (i.e. the output end of the photoelectric coupler) is connected to the front-end module (i.e. Figure 2 The front end in the data acquisition system is a part of the host computer of the data acquisition system, which will not be described in detail in this embodiment. The front end module leads out the optical fiber and is connected to the host computer of the data acquisition system.

[0038] Figure 2 In the process, the input end of the closing acquisition module is connected in series to the control power supply circuit of the circuit breaker closing coil through the workstation terminal block, and the output end of the closing acquisition module is connected to the data acquisition system through the front-end module; the input end of the opening acquisition module is connected in series to the control power supply circuit of the circuit breaker opening coil through the workstation terminal block, and the output end of the opening acquisition module is connected to the data acquisition system through the front-end module.

[0039] In this embodiment, the test current signal range of the opening and closing signal acquisition module is AC / DC: 50mA-20A, and the output peak value is AC / DC: 0-5V after being amplified by the corresponding Hall element and integrator.

[0040] Similarly, the input end of the travel signal acquisition module is connected to the travel sensor fixed to the circuit breaker through the test room workstation terminal block, and the output end of the travel signal acquisition module is connected to the front-end module through a double-shielded cable. The optical fiber is led out from the front-end module and connected to the data acquisition system.

[0041] Based on the above signal acquisition device, the capacity test is carried out. Before the capacity test begins, follow the steps below: Figure 2 As shown, a high-voltage circuit breaker is connected, and the break signal acquisition module is connected in parallel to both ends of the main contact break of the high-voltage circuit breaker through a terminal block; the opening signal and closing signal acquisition modules are connected in series to the control power supply circuit of the opening and closing coils of the circuit breaker; the travel signal acquisition module is connected to the travel sensor installed on the high-voltage circuit breaker.

[0042] 1. The no-load test before the capacity test is as follows:

[0043] When the closing control signal is issued and the circuit breaker is closed, the circuit breaker closing coil is energized and the main contacts are in contact. At this time, the data acquisition system collects the closing coil current signal, the break voltage signal and the travel curve signal through the signal acquisition cabinet; when the opening control signal is issued and the circuit breaker is opened, the circuit breaker opening coil is energized and the main contacts are separated. At this time, the data acquisition system collects the opening coil current signal, the break voltage signal and the travel curve signal through the signal acquisition cabinet.

[0044] like Figure 3 The figure shows the test waveform of CO no-load operation, in which IT0c1 represents the closing coil current, in A; IT0op represents the opening coil current, in A; CSa represents the break voltage, in V; Tr represents the stroke voltage, in V. Figure 3 From the test waveform in, we can know that the time difference from the start of the closing coil to the falling edge of the break voltage is the closing time; the time difference from the start of the opening coil to the rising edge of the break voltage is the opening time; at the same time, the just-opening point is marked on the stroke curve according to the position of the rising edge of the break voltage during the opening, and the just-opening point is used as the just-opening point of the high-voltage circuit breaker during the capacity breaking test (i.e., capacity test). This device can be used to accurately measure the opening and closing time of the circuit breaker before the capacity test of the high-voltage circuit breaker.

[0045] After the no-load test and before the capacity test, the break signal line should be removed to prevent high voltage from being loaded on both ends of the circuit breaker break during the capacity test, thereby damaging the break signal acquisition module. The wiring schematic diagram of the signal acquisition device during the capacity test is as follows: Figure 5 shown.

[0046] 2. Capacity test is as follows:

[0047] Figure 4 This is the principle diagram of the capacity test. When the closing control signal is sent and the circuit breaker is closed, the closing coil of the circuit breaker is energized and the main contacts are in contact. At this time, the data acquisition system collects the closing coil current signal and the stroke curve signal (i.e., the stroke signal) through the signal acquisition cabinet, and measures the breaking current through the Rogowski coil TA connected in series in the loop; when the opening control signal is sent and the circuit breaker is opened, the opening coil of the circuit breaker is energized, the main contacts are separated, and the breaking current is extinguished. At this time, the data acquisition system collects the opening coil current signal and the stroke curve signal through the signal acquisition cabinet, and measures the power supply voltage through the RC voltage divider TV1 connected in parallel in the loop.

[0048] like Figure 6 The figure shows the test waveform of the CO operation of the high-voltage circuit breaker capacity test. In the figure, IT0c1 represents the closing coil current, in A; IT0op is the opening coil current, in A; Ucs is the power supply voltage, in kV; IT0 is the breaking current, in kA; Isyn is the voltage source current, in kA; Tr is the stroke voltage, in V. Figure 6 As can be seen from the test waveform in the figure, the break signal is no longer collected at this time, so there is no break voltage curve in the waveform diagram. The time difference from the start of the closing coil to the start of the current is the closing time; the time difference from the start of the opening coil to the just-opening point marked on the travel curve is the opening time; the time difference from the just-opening point marked on the travel curve to the current zero crossing (i.e. arc extinguishing) is the arcing time.

[0049] This embodiment uses a terminal block to achieve the connection between the signal acquisition cabinet and the high-voltage circuit breaker. In this way, for different products, there is no need to set up a long cable to connect the acquisition cabinet and the circuit breaker. Instead, the terminal block and the signal acquisition cabinet are already connected in advance. When there is a test requirement, the terminal block and the high-voltage short circuit are temporarily connected. In addition, the advantage of using the terminal block is that the screws on the terminal block are fixed to the connection wires at the input end of the acquisition cabinet and the output end of the circuit breaker to avoid the problem of failure to collect signals due to virtual connection.

[0050] If the problem of too long connection lines and line virtual connection is not considered, as another implementation method, the terminal block may not be provided, and the input end of the signal acquisition cabinet may be directly connected to the corresponding components or loops of the high-voltage circuit breaker.

[0051] The principle of the signal acquisition device of the present invention is simple and convenient, easy to operate, and has high safety and reliability. The use of the present invention can not only accurately measure the opening and closing time and arcing time of the high-voltage circuit breaker during no-load test and capacity test, greatly improving the detection efficiency and test success rate, but also ensure the safety of measurement personnel and test equipment, and reduce the test cost.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A signal acquisition device for high-voltage circuit breaker testing, characterized in that: It includes a signal acquisition cabinet, the cabinet body of which is made of a metal material for shielding a magnetic field, and a break signal acquisition board, a closing signal acquisition board, an opening signal acquisition board and a travel signal acquisition board are arranged in the acquisition cabinet, and the components used for measuring the break signal, closing signal, opening signal and travel signal of the high-voltage circuit breaker are integrated into the respective signal acquisition boards to form a break signal acquisition module, a closing signal acquisition module, an opening signal acquisition module and a travel signal acquisition module; each acquisition module is connected to a front-end module of a data acquisition system through a cable, and then the front-end module is connected to a host of the data acquisition system through an optical fiber; The input end of the break signal acquisition module is used to be connected in parallel to the two ends of the main contact break of the high-voltage circuit breaker, the input end of the closing signal acquisition module is used to be connected in series to the control power supply circuit of the closing coil of the circuit breaker, the input end of the opening signal acquisition module is used to be connected in series to the control power supply circuit of the opening coil of the circuit breaker, and the input end of the travel signal acquisition module is used to connect to the travel sensor fixed to the circuit breaker; The signal acquisition device also includes a station terminal block, one port of the station terminal block is connected to the input end of each signal acquisition module, and the other port of the station terminal block is used to connect the two ends of the main contact break of the high-voltage circuit breaker, the control power supply circuit of the closing coil, the control power supply circuit of the opening coil, and the travel sensor on the circuit breaker; The closing signal acquisition board is integrated with a current Hall element and an integral amplifier. The acquisition end of the current Hall element is used to connect to the control power supply circuit of the circuit breaker closing coil, and the output end of the current Hall element is connected to the integral amplifier, which is used to output the closing signal. The opening signal acquisition board is integrated with a current Hall element and an integrating amplifier. The acquisition end of the current Hall element is used to connect to the control power supply circuit of the circuit breaker opening coil, and the output end of the current Hall element is connected to the integrating amplifier, which is used to output the opening signal.

2. The signal acquisition device for high-voltage circuit breaker testing according to claim 1, characterized in that: A power supply module is installed in the signal acquisition cabinet, and the power supply module is connected to each signal acquisition board to provide working power for each signal acquisition module.

3. The signal acquisition device for high-voltage circuit breaker testing according to claim 2, characterized in that: The power supply module is a rectifier converter.

4. The signal acquisition device for high-voltage circuit breaker testing according to claim 1, characterized in that: The break signal acquisition board is integrated with a photoelectric coupler, the primary side of the photoelectric coupler is used to connect the main contact break of the high-voltage circuit breaker, and the secondary side of the photoelectric coupler is used to output the break signal.

5. The signal acquisition device for high-voltage circuit breaker testing according to claim 1, characterized in that: After the no-load test using the signal acquisition device is completed and before the capacity test is performed, the connection line between the break signal acquisition module and the main contact of the high-voltage circuit breaker is disconnected to prevent the signal acquisition module from being damaged during the capacity test.

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