High-voltage circuit breaker synthetic test data acquisition device

Abstract

The application discloses a kind of high voltage circuit breaker synthesis test data acquisition devices, including signal acquisition unit and control unit.Signal acquisition unit contains signal transmitter, fracture acquisition circuit and stroke acquisition circuit;Fracture acquisition circuit is connected with the three-phase fracture of measured circuit breaker, and the on-off state of three-phase fracture is synthesized into a road fracture signal output, stroke acquisition circuit is connected with stroke sensor and outputs stroke signal, and the output end of both is connected with signal transmitter through first selection switch;First selection switch is connected with both circuits when idle, and fracture acquisition circuit is disconnected when test power is connected, and stroke acquisition circuit is kept connected.Control unit contains signal receiver and data acquisition terminal in communication with signal transmitter.The acquisition device of the application can calibrate stroke-time curve by fracture on-off time when idle, and the loop is not subjected to recovery voltage after pressurization, to avoid breakdown and electromagnetic interference, and the transmission channel is saved.

Description

Technical Field

[0001] This invention relates to the field of high-voltage circuit breaker testing equipment technology, and in particular to a high-voltage circuit breaker composite test data acquisition device. Background Technology

[0002] The breaking capacity of high-voltage circuit breakers needs to be verified through breaking tests. Since direct testing requires a huge power capacity, a composite test circuit is generally used in engineering. That is, a current source circuit provides the short-circuit current required for breaking, and a voltage source circuit provides the recovery voltage applied to the break point after breaking. The two are used in sequence for the test circuit breaker to evaluate its breaking performance with a smaller test capacity.

[0003] In the synthetic test, in addition to recording the current and voltage of the circuit, it is also necessary to simultaneously acquire the operating characteristic data of the test circuit breaker itself, including the driving voltage and current of the closing and opening coils, the on / off status of the three-phase contacts, and the travel signal output by the travel sensor. Among them, the on / off status of the contacts is used to determine the opening and closing times of each phase contact and the synchronicity of the three phases; the travel signal is used to obtain the travel-time curve, and based on this, mechanical characteristic parameters such as the initial opening speed, average speed, and overtravel are calculated.

[0004] In existing fault status acquisition schemes, separate acquisition channels are typically set up for phases A, B, and C, with each phase's on / off signal occupying a separate transmission channel to be sent to the recording device. This approach has two drawbacks: First, the three-phase fault status occupies three transmission channels, while the synthetic test also needs to simultaneously transmit multiple analog signals such as travel signals, closing coil drive signals, and opening coil drive signals. With a limited number of signal transmitter channels, channel resources are very scarce, often requiring additional transmission equipment or time-division multiplexing strategies, increasing system complexity. Second, the three-phase fault signals belong to different physical channels, and it is difficult to ensure that the signal conditioning circuit parameters, transmission path lengths, and device response characteristics of each channel are completely consistent. The inherent transmission delay differences between channels will be directly superimposed on the measurement results of the three-phase opening and closing times, thus limiting the measurement accuracy of the three-phase synchronicity.

[0005] In addition, in the no-load mechanical characteristic test, the acquisition circuit is usually connected to the three-phase break of the test specimen. The stroke curve is calibrated by using the on and off time of the break as the time reference, thereby determining the position of the break point and the closing point. This method has intuitive criteria and high time resolution.

[0006] However, there are difficulties in directly applying this method to the breaking test condition. After the test specimen breaks, it needs to withstand a high-amplitude recovery voltage applied by the voltage source circuit. If the break acquisition circuit is still electrically connected to the three-phase break, its terminals and internal components will directly bear this high voltage, which can easily cause insulation breakdown and damage the acquisition circuit. It may also introduce strong electromagnetic interference, causing distortion and falsification of other signals in the same acquisition system. If the break acquisition circuit is completely disconnected before applying the test power supply to avoid the above risks, then the direct criterion for the opening time is lost. It is difficult to accurately determine the breaking point on the stroke-time curve based solely on the stroke signal, making it impossible to reliably measure key parameters such as the opening time and breaking speed in the breaking test.

[0007] In summary, it is necessary to further improve the data acquisition device for high-voltage circuit breaker synthesis tests. Summary of the Invention

[0008] The purpose of this invention is to provide a high-voltage circuit breaker synthetic test data acquisition device that can simultaneously acquire the on / off status of three-phase breaks with fewer transmission channels and eliminate the influence of multi-channel time delay differences on the three-phase synchronicity measurement, while taking into account the accurate calibration of travel signals under no-load conditions and the high-voltage isolation of the break acquisition branch under the breaking condition.

[0009] To achieve the above objectives, the present invention provides a high-voltage circuit breaker synthetic test data acquisition device, comprising: The signal acquisition unit includes a signal transmitter, a break point acquisition circuit, and a travel acquisition circuit; The output terminal of the break point acquisition circuit is connected to the signal transmitter, and the input terminal of the break point acquisition circuit is used to connect to the three-phase break points of the circuit breaker under test, and is configured to combine the on / off states of the three-phase break points into a single break point signal output. The output terminal of the travel acquisition circuit is connected to the signal transmitter, and the input terminal of the travel acquisition circuit is used to connect to the travel sensor installed on the circuit breaker under test and is configured to output a travel signal. The output terminals of the break point acquisition circuit and the travel acquisition circuit are respectively connected to the signal transmitter via a first selection switch. The first selection switch is configured to: connect both the break point acquisition circuit and the travel acquisition circuit to the signal transmitter when the circuit breaker under test is unloaded, and disconnect the connection between the break point acquisition circuit and the signal transmitter when the circuit breaker under test is connected to the test power supply, while maintaining the connection between the travel acquisition circuit and the signal transmitter. The control unit includes a signal receiver communicatively connected to the signal transmitter, and a data acquisition terminal connected to the signal receiver.

[0010] Preferably, the fault acquisition circuit includes a BCD encoding circuit. The input terminals of the BCD encoding circuit are used to connect to the A-phase fault, B-phase fault, and C-phase fault of the circuit breaker under test, respectively. The BCD encoding circuit is configured to map the on / off states of the A-phase fault, B-phase fault, and C-phase fault to superimposed voltage amplitudes with fixed proportional weights, and output them as a fault signal from the output terminal of the fault acquisition circuit.

[0011] Preferably, in the BCD encoding circuit, the ratio of the voltage weights corresponding to the on / off states of phase A, phase B, and phase C is 4:2:1.

[0012] Preferably, the signal acquisition unit further includes a closing acquisition circuit and a opening acquisition circuit; the output terminal of the closing acquisition circuit is connected to the signal transmitter, and the input terminal of the closing acquisition circuit is used to connect to the closing coil of the circuit breaker under test and is configured to acquire the driving signal of the closing coil; the output terminal of the opening acquisition circuit is connected to the signal transmitter, and the input terminal of the opening acquisition circuit is used to connect to the opening coil of the circuit breaker under test and is configured to acquire the driving signal of the opening coil.

[0013] Preferably, the closing acquisition circuit includes a first current sensor and a first voltage sensor disposed between the closing coil and the drive power supply. The first current sensor and the first voltage sensor are connected to the signal transmitter through a second selection switch. The second selection switch is used to selectively connect the current signal or the voltage signal to the signal transmitter. The circuit breaker acquisition circuit includes a second current sensor and a second voltage sensor disposed between the circuit breaker coil and the drive power supply. The second current sensor and the second voltage sensor are connected to the signal transmitter through a third selection switch. The third selection switch is used to selectively connect the current signal or the voltage signal to the signal transmitter.

[0014] Preferably, the second selection switch is further configured to switch the current range by switching the number of through-hole turns of the first current sensor, and to switch the voltage range by switching the voltage division ratio of the first voltage sensor. The third selection switch is also configured to switch the current range by switching the number of through-hole turns of the second current sensor, and to switch the voltage range by switching the voltage division ratio of the second voltage sensor.

[0015] Preferably, the signal transmitter is an analog optical transceiver transmitter, the signal receiver is an analog optical transceiver receiver, and the analog optical transceiver transmitter and the analog optical transceiver receiver are connected by optical fiber.

[0016] Preferably, the signal acquisition unit further includes a first power supply circuit for providing low-voltage drive power to the acquisition module, and the acquisition module includes the signal transmitter, the break acquisition circuit, the travel acquisition circuit, the mains closing acquisition circuit, and the opening acquisition circuit; The first power supply circuit includes a first power adapter module, a first battery module, and a fourth selection switch. The fourth selection switch is connected to the first power adapter module, the first battery module, and the acquisition module. The first power adapter module is used to connect to an AC power source. The fourth selection switch is used to connect the first power adapter module to the acquisition module and charge the first battery module when the circuit breaker under test is in an unloaded state. The fourth selection switch is also used to disconnect the connection with the first power adapter module and connect the first battery module to the acquisition module when the circuit breaker under test is connected to a test power source.

[0017] Preferably, the power module further includes an isolation transformer connected to the first power adapter module and a surge protector connected to the isolation transformer.

[0018] Preferably, the control unit further includes a second power supply circuit, which includes a second power adapter module, a second battery module, and a fifth selector switch. The fifth selector switch is connected to the second power adapter module, the second battery module, and the signal receiver. The fifth selector switch is used to connect the second power adapter module to the signal receiver and charge the second battery module when the circuit breaker under test is in an unloaded state. The fifth selector switch is also used to disconnect the connection with the second power adapter module and connect the second battery module to the signal receiver when the circuit breaker under test is connected to a test power supply.

[0019] Compared with existing technologies, firstly, the break acquisition circuit combines the on / off states of the three-phase breaks into a single break signal output, which only occupies one transmission channel to simultaneously reflect the state of the three-phase contacts. This reduces the number of transmission channels and avoids timing errors caused by time delay inconsistencies between multiple channels. Secondly, with the help of the first selector switch, the break acquisition circuit and the travel acquisition circuit are simultaneously connected to the signal transmitter under no-load conditions. The travel-time curve can be calibrated using the break opening and closing times to establish the correspondence between the breaking point, the closing point, and the travel curve. After the circuit breaker under test is connected to the test power supply, the first selector switch disconnects the connection between the break acquisition circuit and the signal transmitter, so that the acquisition circuit is no longer subjected to the high amplitude recovery voltage applied by the voltage source circuit, avoiding insulation breakdown and strong electromagnetic interference introduced by this branch. At the same time, the travel acquisition circuit is kept connected, and the travel signal can be continuously acquired. The breaking point can be determined on the travel curve based on the calibration relationship obtained from the no-load test. Thus, key parameters such as opening time and breaking speed can still be reliably obtained under the breaking condition, solving the problem of difficulty in balancing high-voltage isolation and accurate calibration of the travel curve. Furthermore, the separate design of the signal transmitter and receiver enables electrical isolation between the high-potential acquisition side and the control side, as well as long-distance signal transmission, thereby improving the reliability of the acquired data and the safety of the experiment. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the data acquisition device in an embodiment of the present invention. Detailed Implementation

[0021] To illustrate the technical content, structural features, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0022] This embodiment discloses a high-voltage circuit breaker synthesis test data acquisition device, which is applied to a high-voltage circuit breaker synthesis test system composed of a current source circuit and a voltage source circuit, to acquire data to be analyzed during the synthesis test process.

[0023] like Figure 1 The device includes a signal acquisition unit 100 located on the test site side and a control unit 200 located on the control room side.

[0024] The signal acquisition unit 100 includes a signal transmitter, a break acquisition circuit L1, a travel acquisition circuit L2, and a first selection switch.

[0025] The control unit 200 includes a signal receiver and a data acquisition terminal. The signal receiver is communicatively connected to the signal transmitter, and the output of the signal receiver is connected to the analog input port of the data acquisition terminal.

[0026] The input terminals of the fault acquisition circuit L1 are equipped with three pairs of terminals, which are used to connect to the two ends of the A-phase fault, B-phase fault, and C-phase fault of the circuit breaker under test 300, respectively. The fault acquisition circuit L1 has an internal low-voltage detection power supply, which detects the fault signals generated at its output terminals that reflect the on / off status of the three-phase faults, and combines the on / off status of the three-phase faults into a single fault signal for output.

[0027] The input terminal of the travel acquisition circuit L2 is used to connect to the travel sensor installed on the transmission component of the circuit breaker 300 under test. The travel sensor moves with the contact and outputs an electrical signal corresponding to the contact travel. After filtering and amplitude conditioning the electrical signal, the travel acquisition circuit L2 generates a travel signal at its output terminal.

[0028] The output of the break point acquisition circuit L1 is connected to channel 1 of the signal transmitter via the first contact of the first selector switch. The output of the travel acquisition circuit L2 is connected to channel 2 of the signal transmitter via a voltage divider, a current limiting resistor, and the second contact of the first selector switch. The signal ground of each acquisition circuit is connected to the analog ground of the signal transmitter.

[0029] The first selection switch is configured such that when the circuit breaker under test 300 is in an unloaded state (testing its mechanical characteristics), both the first and second contacts are closed, and the break-point acquisition circuit L1 and the travel acquisition circuit L2 are simultaneously connected to the signal transmitter. When the circuit breaker under test 300 is connected to the test power supply, the first contact opens and the second contact remains closed, that is, the connection between the break-point acquisition circuit L1 and the signal transmitter is disconnected, and only the signal path of the travel acquisition circuit L2 is retained.

[0030] The device operates in two phases. The first phase is the no-load calibration phase: the circuit breaker under test 300 is not connected to the test power supply, and no-load opening and closing operations are performed. The signal transmitter simultaneously transmits the break point signal and the travel signal to the signal receiver, and the data acquisition terminal records the two signals on the same time axis. During the opening process, the moment when the break point signal changes is the moment when the contact just opens. The data acquisition terminal reads the travel value corresponding to the travel signal at that moment and marks the point of just opening on the travel-time curve. The closing process is similarly calibrated to mark the point of just closing.

[0031] Since the correspondence between the break separation and the stroke value is determined by the mechanical structure of the circuit breaker 300 under test, it remains stable in multiple operations of the same test piece. Therefore, a reusable correspondence can be established with a single no-load calibration.

[0032] The second stage is the breaking test stage: the circuit breaker under test 300 is connected to the test power supply, and the first selector switch disconnects the channel where the breaking point acquisition circuit L1 is located. There is no electrical path between the breaking point acquisition circuit L1 and the signal transmitter, and the recovery voltage applied to the breaking point by the voltage source circuit will not enter the signal transmitter through this channel. The travel signal continues to be acquired and transmitted. The data acquisition terminal finds the moment when the travel signal reaches the travel value on the travel-time curve of the breaking test based on the travel value obtained from the no-load calibration. This moment is the breaking point moment of this breaking test, and then the opening time and breaking speed are calculated.

[0033] In some alternative implementations, the first selection switch can be implemented as a manual toggle switch, an electromagnetic relay, or a contactor, as long as the electrical connection between the break acquisition circuit L1 and the signal transmitter can be reliably disconnected before the test power is applied.

[0034] The travel sensor can be a linear resistive displacement sensor, a rotary encoder, or a magnetostrictive displacement sensor. The travel acquisition circuit L2 is configured as a voltage follower conditioning circuit or a frequency-to-voltage conversion circuit, depending on the sensor output format. The data acquisition terminal can be a digital oscilloscope, a waveform recorder, or a computer equipped with a data acquisition card.

[0035] In this embodiment, because the break point acquisition circuit L1 and the travel acquisition circuit L2 are connected to the signal transmitter via a first selection switch, the break point signal channel can be disconnected separately before the breaking test without affecting the travel signal channel, and the travel signal can be continuously obtained throughout the test. Furthermore, since the two signals share the same time reference during the no-load phase, the position of the break point on the travel curve can be directly calibrated by the break point opening and closing time. Therefore, even under the breaking condition where the break point acquisition channel is isolated, the break point opening time can still be reliably determined based on the calibration relationship, solving the problem of simultaneously achieving high-voltage isolation and accurate calibration of the break point. Further, the break point acquisition circuit L1 includes a BCD encoding circuit. The three inputs of the BCD encoding circuit correspond to the A-phase break, B-phase break, and C-phase break, respectively, and its output is a superimposed voltage signal.

[0036] Specifically, taking a negative reference voltage of -8V, the contribution of phase A's closed circuit to the output voltage is 4V, phase B's closed circuit contributes 2V, and phase C's closed circuit contributes 1V. The voltage weighting ratio corresponding to the three-phase on / off states is 4:2:1. Therefore, the output voltage forms eight discrete levels between 0V and 7V: 0V when all three phases are open, 7V when all three phases are closed, and each intermediate state corresponds to a unique voltage amplitude. For example, an output of 6V indicates that phases A and B are closed, and phase C is open. The data acquisition terminal performs level analysis on this signal to reconstruct the on / off state of each of the three phases at any given time, and directly obtains the synchronicity of the three-phase opening and closing from the time difference between adjacent level transitions.

[0037] In this embodiment, since the three-phase break states are mapped to superimposed voltage amplitudes with fixed weights and synthesized into a single break signal, the break states that originally required three transmission channels only occupy one input channel of the signal transmitter. The saved channel can be used for the transmission of other signals. At the same time, since the three-phase states are presented on the same signal, there is no timing error introduced by the inconsistency of transmission delay between multiple channels, and the accuracy of the three-phase synchronicity measurement is improved.

[0038] On the other hand, the three pairs of input terminals of the fault acquisition circuit L1 are composed of quick-release terminals. The fixed side of the quick-release terminal is mounted on the terminal block of the fault acquisition circuit L1, and the movable side is crimped to the end of the measuring cable connecting the three-phase fault. After the circuit breaker under test 300 is completed under no-load test and before the test power is connected, the operator pulls the movable side of the quick-release terminal completely away from the fixed side, thereby disconnecting the electrical connection channel between the fault acquisition circuit L1 and the circuit breaker under test 300, so that the measuring cable no longer constitutes a conductive path from the fault to the acquisition circuit. The quick-release terminal can be implemented using an aviation plug or a spring clip terminal.

[0039] In this embodiment, the scheme works in conjunction with the disconnection action of the first selector switch to form double isolation. The first selector switch cuts off the path from the output of the fault acquisition circuit L1 to the signal transmitter, and the quick-release terminal cuts off the path from the fault of the circuit breaker under test 300 to the input of the fault acquisition circuit L1. Since there is no continuous conductive path between the point where the recovery voltage is applied and the signal transmitter, even if the insulation margin of the internal components of the fault acquisition circuit L1 is limited, it will not be broken down by the recovery voltage. At the same time, the path for conducting electromagnetic interference to the acquisition system through this branch is eliminated.

[0040] Furthermore, in order to simultaneously obtain the excitation status of the operating mechanism, the signal acquisition unit 100 in this embodiment also includes a closing acquisition circuit L3 and a closing acquisition circuit L4.

[0041] The closing acquisition circuit L3 includes a first current sensor and a first voltage sensor. The first current sensor is connected in series on the power supply wire between the operating mechanism drive power supply and the closing coil of the circuit breaker under test 300, and senses the drive current of the closing coil in a through-hole manner. The two input terminals of the first voltage sensor are connected in parallel across the two ends of the closing coil to sense the drive voltage of the closing coil.

[0042] The signal output terminals of the first current sensor and the first voltage sensor are respectively connected to the two selection contacts of the second selection switch. The common terminal of the second selection switch is connected to channel 3 of the signal transmitter, which is used to selectively connect the current signal or the voltage signal to the signal transmitter.

[0043] The structure of the circuit breaker acquisition circuit L4 corresponds to this, including a second current sensor and a second voltage sensor.

[0044] The second current sensor is connected in series on the power supply wire between the drive power supply and the trip coil, and the second voltage sensor is connected in parallel across the two ends of the trip coil. The signal output terminals of the two sensors are selected by the third selector switch and connected to channel 4 of the signal transmitter.

[0045] In this embodiment, the first current sensor and the second current sensor are feedthrough current sensors. The first voltage sensor and the second voltage sensor are implemented using a resistor divider network in conjunction with an isolation amplifier.

[0046] Considering that the rated voltage of the coils of different test samples varies, such as DC24V and DC220V, and the driving current ranges from several amperes to tens of amperes, each sensor is preferably configured with a multi-range structure. The second selection switch is also configured to switch the current range by changing the number of turns in the first current sensor, and to switch the voltage range by changing the voltage division ratio of the first voltage sensor. The third selection switch is also configured to switch the current range by changing the number of turns in the second current sensor, and to switch the voltage range by changing the voltage division ratio of the second voltage sensor.

[0047] For example, the input voltage divider network of the first voltage sensor is set with two voltage division ratios of 60V and 300V, and the number of through-hole turns of the first current sensor is set with two levels of 2A and 20A. These can be switched by the panel selector switch to ensure that the signal amplitude of each type of test sample falls within 30% to 90% of the full range of the signal transmitter input channel, thus avoiding insufficient waveform resolution due to excessive range or channel saturation due to excessively small range.

[0048] During the tripping operation, the initial rising edge of the tripping coil drive current waveform corresponds to the initial moment of the operating mechanism tripping. The data acquisition terminal takes this moment as the starting point of timing and the moment of tripping marked on the stroke curve as the ending point of timing. The difference between the two is the tripping time.

[0049] Similarly, the measurement of closing time is based on the starting moment of the closing coil current. Since the current signal and voltage signal are selectively connected to the same input channel via a selector switch, under the condition of a limited number of signal transmitter channels, a single test can select to record either the current waveform or the voltage waveform according to the assessment item, and two operations can cover all electrical quantities without increasing the number of transmission channels.

[0050] In another preferred embodiment, the transmission link between the signal transmitter and the signal receiver is specifically implemented as follows: The signal transmitter is a multi-channel analog optical transceiver transmitter, and the signal receiver is a matching analog optical transceiver receiver, with the two connected by optical fiber.

[0051] The analog-to-optical transceiver transmitter modulates the analog signals from each input channel into optical signals, which are then transmitted via optical fiber. The analog-to-optical transceiver receiver demodulates and restores the signals to analog before sending them to the data acquisition terminal. The channel bandwidth of the optical transceiver is selected from DC to 1MHz to ensure complete transmission of the level transition edges of the interrupted signal and the rapid rising edges of the coil current.

[0052] Since optical fiber is the dielectric transmission medium, there is no metallic connection between the high-potential area where the signal acquisition unit 100 is located and the control room where the control unit 200 is located. The potential difference between the two ends will not form a ground loop current, and the common-mode interference generated during the synthetic test discharge process cannot enter the data acquisition terminal along the transmission path. At the same time, the optical signal transmission does not produce waveform distortion caused by amplitude attenuation with distance, and the waveform fidelity is maintained under long-distance transmission conditions.

[0053] On the other hand, in order to prevent high voltage surges during the test from entering the acquisition side equipment along the power supply circuit, the signal acquisition unit 100 in this embodiment also includes a first power supply circuit for providing low voltage drive power to the acquisition module. The acquisition module includes a signal transmitter, a break acquisition circuit L1, a travel acquisition circuit L2, a closing acquisition circuit L3, and a opening acquisition circuit L4.

[0054] The first power supply circuit includes a first power adapter module, a first battery module, and a fourth selection switch.

[0055] The input terminal of the first power adapter module is used to connect to the AC power supply of the test site, and its output terminal outputs low-voltage DC power. The first battery module is a rechargeable battery pack, and its charging terminal is connected to the output terminal of the first power adapter module via a charging branch.

[0056] The fourth selector switch has its first selector contact connected to the output terminal of the first power adapter module, its second selector contact connected to the discharge terminal of the first battery module, and its common terminal connected to the power supply bus of the acquisition module. The fourth selector switch is configured such that: when the circuit breaker under test 300 is in an unloaded state, the common terminal is connected to the first selector contact, the acquisition module is powered by the first power adapter module, and the first power adapter module charges the first battery module via the charging branch. When the circuit breaker under test 300 is connected to the test power supply, the common terminal is disconnected from the first selector contact and connected to the second selector contact, cutting off the connection between the acquisition module and the first power adapter module and the AC power supply, and the first battery module powers the acquisition module instead.

[0057] The first power adapter module can be a switching power supply module with constant voltage output, and the first battery module can be a lithium battery pack or a sealed lead-acid battery pack. Its output voltage is selected according to the power supply requirements of the acquisition module, typically DC12V or DC24V. The capacity is selected according to the total power consumption of the acquisition module and the duration of a single interruption test to ensure that the acquisition module can maintain normal operation when disconnected from AC power.

[0058] Because the acquisition module is completely disconnected from the AC power grid during the interruption test, the power supply circuit no longer constitutes a path for high voltage to enter the acquisition module. The power grid interference caused by the large current interruption on the test site cannot be conducted to the signal transmitter and each acquisition circuit through the power line. Furthermore, because the first battery module is continuously charged during the no-load phase, it ensures that the battery has sufficient charge when switching to discharge power supply, and the power supply to the acquisition module is uninterrupted during the switching between the two power supply modes.

[0059] Furthermore, to suppress surges and common-mode interference introduced by the AC power supply, this embodiment adds an isolation transformer and a surge protector to the first power supply circuit. The primary winding of the isolation transformer is connected to the AC power supply, and the secondary winding is connected to the input terminal of the first power adapter module. There is no electrical connection between the primary and secondary windings; energy is transferred only through magnetic coupling, thus cutting off the common-mode conduction path between the AC power supply side and the acquisition side. The surge protector is connected in parallel between the power supply line between the isolation transformer and the first power adapter module and the protective ground. When a surge voltage exceeding its operating voltage occurs on the line, the surge protector quickly conducts to discharge the surge energy to the protective ground, clamping the voltage applied to the input terminal of the first power adapter module within a safe range.

[0060] Corresponding to the power supply scheme of the signal acquisition unit 100, in order to enable the control unit 200 to operate independently from the mains power during the test, the control unit 200 in this embodiment also includes a second power supply circuit.

[0061] The second power supply circuit includes a second power adapter module, a second battery module, and a fifth selection switch.

[0062] The input terminal of the second power adapter module is used to connect to the AC power supply of the control room, and the output terminal outputs low-voltage DC power; the charging terminal of the second battery module is connected to the output terminal of the second power adapter module via the charging branch; the first selection contact of the fifth selector switch is connected to the output terminal of the second power adapter module, the second selection contact is connected to the discharge terminal of the second battery module, and the common terminal is connected to the power supply terminal of the signal receiver.

[0063] The fifth selector switch is configured such that when the circuit breaker under test 300 is in an unloaded state, the common terminal is connected to the first selector contact, the signal receiver is powered by the second power adapter module, and the second power adapter module charges the second battery module; when the circuit breaker under test 300 is connected to the test power supply, the common terminal switches to the second selector contact, disconnects from the second power adapter module, and the second battery module powers the signal receiver instead.

[0064] This embodiment isolates the signal receiver on the control side from the AC power grid during the switching test, preventing interference from the control room power line from entering the data acquisition terminal via the signal receiver and ensuring the purity of the signal restored on the receiving side. In conjunction with the first power supply circuit on the signal acquisition unit 100 side, both the transmitting and receiving ends are independently powered by their respective batteries during the test phase, and the entire signal transmission link also achieves mutual isolation between the transmitting and receiving ends on the power supply side.

[0065] The following section describes the application process of the aforementioned data acquisition device using a complete synthetic experiment. The test object is a certain type of high-voltage circuit breaker with a rated voltage of DC220V for its trip coil, and the travel sensor is a linear resistance displacement sensor.

[0066] During the test preparation phase, the three pairs of quick-release terminals of the break acquisition circuit L1 are connected to the A-phase, B-phase, and C-phase break of the circuit breaker under test 300, respectively. The travel acquisition circuit L2 is connected to the travel sensor. The first current sensor and the first voltage sensor are connected to the closing circuit, and the second current sensor and the second voltage sensor are connected to the opening circuit.

[0067] Based on the rated voltage of the trip coil (DC220V), the voltage division ratio of the second voltage sensor is set to 300V, so that the amplitude of its output signal falls at approximately 73% of the full scale of the signal transmitter input channel. Both contacts of the first selector switch are set to closed, and the fourth and fifth selector switches are set to the AC power supply side.

[0068] During the no-load calibration phase, the circuit breaker under test (300) is not connected to the test power supply, and no-load closing and opening operations are performed sequentially. During opening, the three-phase contacts separate sequentially, and the break signal output by the break acquisition circuit L1 drops from 7V step by step. The data acquisition terminal records the timing of each level transition and reads the travel value corresponding to the travel signal at the first break signal transition (separation of the first phase contact), recording this travel value as the break point travel value S0. Simultaneously, the synchronicity of the three-phase opening is obtained from the time interval of the three level transitions. The closing operation is used to calibrate the break point travel value. At this point, the break point and break point on the travel-time curve have been calibrated based on the break opening and closing times.

[0069] During the breaking test phase, first disconnect the first contact of the first selector switch while keeping the second contact closed, then disconnect the three pairs of quick-release terminals of the break acquisition circuit L1, then switch the fourth and fifth selector switches to the battery power supply side, and finally connect the circuit breaker under test 300 to the test power supply.

[0070] After the synthetic test is triggered, the current source circuit provides short-circuit current, the voltage source circuit applies recovery voltage, and the circuit breaker under test 300 performs tripping. During this process, the fault acquisition circuit L1 is doubly disconnected, and the recovery voltage will not enter the acquisition system; the travel acquisition circuit L2 continuously acquires the travel signal, and the drive current waveform of the second current sensor is sent to the signal transmitter via the third selection switch. All signals are transmitted to the signal receiver via optical fiber and recorded by the data acquisition terminal.

[0071] During the data processing stage, the data acquisition terminal locates the moment when the travel signal reaches the just-opening travel value S0 on the travel-time curve of the breaking test, and determines it as the just-opening moment of this breaking test; the opening time is obtained by taking the rising edge of the opening coil drive current waveform as the starting point of timing and the just-opening moment as the ending point; within the specified travel interval or specified time window after the just-opening moment, the just-opening speed is calculated from the slope of the travel curve; and the average speed, overtravel and other mechanical characteristic parameters are calculated in combination with the entire travel curve.

[0072] Through this process, under the premise that the fault acquisition channel is completely isolated during the breaking stage, key parameters such as the opening time and the initial opening speed can still be reliably measured. The measurement results are consistent with the results obtained by directly judging the opening and closing time of the fault under no-load conditions.

[0073] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A data acquisition device for a high-voltage circuit breaker synthesis test, characterized in that, include: The signal acquisition unit includes a signal transmitter, a break point acquisition circuit, and a travel acquisition circuit; The output terminal of the break point acquisition circuit is connected to the signal transmitter, and the input terminal of the break point acquisition circuit is used to connect to the three-phase break points of the circuit breaker under test, and is configured to combine the on / off states of the three-phase break points into a single break point signal output. The output terminal of the travel acquisition circuit is connected to the signal transmitter, and the input terminal of the travel acquisition circuit is used to connect to the travel sensor installed on the circuit breaker under test and is configured to output a travel signal. The output terminals of the break point acquisition circuit and the travel acquisition circuit are respectively connected to the signal transmitter via a first selection switch. The first selection switch is configured to: connect both the break point acquisition circuit and the travel acquisition circuit to the signal transmitter when the circuit breaker under test is unloaded, and disconnect the connection between the break point acquisition circuit and the signal transmitter when the circuit breaker under test is connected to the test power supply, while maintaining the connection between the travel acquisition circuit and the signal transmitter. The control unit includes a signal receiver communicatively connected to the signal transmitter, and a data acquisition terminal connected to the signal receiver.

2. The high-voltage circuit breaker synthetic test data acquisition device according to claim 1, characterized in that, The fault acquisition circuit includes a BCD encoding circuit. The input terminals of the BCD encoding circuit are used to connect to the A-phase fault, B-phase fault, and C-phase fault of the circuit breaker under test, respectively. The BCD encoding circuit is configured to map the on / off states of the A-phase fault, B-phase fault, and C-phase fault to superimposed voltage amplitudes with fixed proportional weights, and output them as a fault signal from the output terminal of the fault acquisition circuit.

3. The high-voltage circuit breaker synthetic test data acquisition device according to claim 2, characterized in that, In the BCD encoding circuit, the voltage weighting ratio corresponding to the on / off states of phase A, phase B, and phase C is 4:2:

1.

4. The high-voltage circuit breaker synthetic test data acquisition device according to claim 1, characterized in that, The signal acquisition unit further includes a closing acquisition circuit and a opening acquisition circuit; the output terminal of the closing acquisition circuit is connected to the signal transmitter, and the input terminal of the closing acquisition circuit is used to connect to the closing coil of the circuit breaker under test and is configured to acquire the driving signal of the closing coil; the output terminal of the opening acquisition circuit is connected to the signal transmitter, and the input terminal of the opening acquisition circuit is used to connect to the opening coil of the circuit breaker under test and is configured to acquire the driving signal of the opening coil.

5. The high-voltage circuit breaker synthetic test data acquisition device according to claim 4, characterized in that, The closing acquisition circuit includes a first current sensor and a first voltage sensor disposed between the closing coil and the driving power supply. The first current sensor and the first voltage sensor are connected to the signal transmitter through a second selection switch. The second selection switch is used to selectively connect the current signal or the voltage signal to the signal transmitter. The circuit breaker acquisition circuit includes a second current sensor and a second voltage sensor disposed between the circuit breaker coil and the drive power supply. The second current sensor and the second voltage sensor are connected to the signal transmitter through a third selection switch. The third selection switch is used to selectively connect the current signal or the voltage signal to the signal transmitter.

6. The high-voltage circuit breaker synthetic test data acquisition device according to claim 5, characterized in that, The second selection switch is also configured to switch the current range by switching the number of through-hole turns of the first current sensor, and to switch the voltage range by switching the voltage division ratio of the first voltage sensor. The third selection switch is also configured to switch the current range by switching the number of through-hole turns of the second current sensor, and to switch the voltage range by switching the voltage division ratio of the second voltage sensor.

7. The high-voltage circuit breaker synthetic test data acquisition device according to claim 1, characterized in that, The signal transmitter is an analog optical transceiver transmitter, and the signal receiver is an analog optical transceiver receiver. The analog optical transceiver transmitter and the analog optical transceiver receiver are connected by optical fiber.

8. The high-voltage circuit breaker synthetic test data acquisition device according to claim 4, characterized in that, The signal acquisition unit further includes a first power supply circuit for providing low-voltage drive power to the acquisition module. The acquisition module includes the signal transmitter, the break acquisition circuit, the travel acquisition circuit, the closing acquisition circuit, and the opening acquisition circuit. The first power supply circuit includes a first power adapter module, a first battery module, and a fourth selection switch. The fourth selection switch is connected to the first power adapter module, the first battery module, and the acquisition module. The first power adapter module is used to connect to an AC power source. The fourth selection switch is used to connect the first power adapter module to the acquisition module and charge the first battery module when the circuit breaker under test is in an unloaded state. The fourth selection switch is also used to disconnect the connection with the first power adapter module and connect the first battery module to the acquisition module when the circuit breaker under test is connected to a test power source.

9. The high-voltage circuit breaker synthetic test data acquisition device according to claim 8, characterized in that, The power module also includes an isolation transformer connected to the first power adapter module and a surge protector connected to the isolation transformer.

10. The high-voltage circuit breaker synthetic test data acquisition device according to claim 1, characterized in that, The control unit further includes a second power supply circuit, which includes a second power adapter module, a second battery module, and a fifth selector switch. The fifth selector switch is connected to the second power adapter module, the second battery module, and the signal receiver. The fifth selector switch is used to connect the second power adapter module to the signal receiver and charge the second battery module when the circuit breaker under test is in an unloaded state. The fifth selector switch is also used to disconnect the connection with the second power adapter module and connect the second battery module to the signal receiver when the circuit breaker under test is connected to the test power supply.

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