Multi-winding CT polarity intelligent pulse testing device and electronic equipment

Abstract

The invention provides a multi-winding CT polarity intelligent pulse testing device and electronic equipment, and the device comprises a power module which is used for providing a working power supply; the primary pulse generation module is used for outputting direct-current pulse current to the primary side of the detected current transformer; the secondary sampling module comprises at least two secondary sampling units, and the secondary sampling units are independently connected to different secondary windings of the detected current transformer and used for synchronously collecting pulse current signals induced by the windings; the control module is used for triggering the primary pulse generation module to output direct-current pulse current, receiving the pulse current signal of each secondary sampling unit and generating a corresponding polarity judgment result according to the polarity direction of each pulse current signal; and the display module is used for simultaneously displaying polarity judgment results corresponding to all the secondary windings. According to the invention, efficient synchronous detection and visual determination of the multi-winding CT polarity can be realized, and the multi-winding synchronous test efficiency and accuracy are improved.

Description

Technical Field

[0001] This application relates to the field of power system automation technology, and in particular to a multi-winding CT polarity intelligent pulse testing device and electronic equipment. Background Technology

[0002] Current transformer (CT) polarity testing is a critical step in power system infrastructure construction, maintenance, and technical upgrades. Especially when verifying the secondary circuit wiring of multi-winding CTs, its correctness directly affects the reliability of relay protection, metering, and other systems. Traditional testing methods generally employ a combination of dry cell batteries and a DC milliammeter: one tester applies a momentary DC current to the primary side of the CT via a dry cell battery, while another tester simultaneously observes the deflection of the DC milliammeter pointer on the secondary side to determine the polarity.

[0003] However, traditional testing methods have several drawbacks. For example, testing requires at least two people to operate simultaneously, and multiple winding CTs need to be tested individually and repeatedly. When there are a large number of CTs and windings in a substation, this process is extremely time-consuming. Furthermore, when the primary current is too low (e.g., insufficient battery power), the secondary milliammeter pointer deflects only slightly, easily leading to misjudgments. When the current is too high, the pointer may overshoot its range and damage the instrument. Additionally, the test results lack a self-holding function, requiring constant monitoring of the pointer's movement, which can easily lead to missed judgments due to visual fatigue or operational distraction. Therefore, existing CT polarity testing technology suffers from low testing efficiency and insufficient accuracy when facing scenarios involving simultaneous testing of multiple windings.

[0004] The preceding description is intended to provide general background information and does not necessarily constitute prior art. Summary of the Invention

[0005] To address the issues of low testing efficiency and insufficient accuracy in existing CT polarity testing technologies when dealing with multi-winding synchronous testing scenarios, this application provides an intelligent pulse testing device and electronic equipment for multi-winding CT polarity. This device enables efficient synchronous detection and intuitive determination of the polarity of multi-winding CTs, thereby improving the efficiency and accuracy of multi-winding synchronous testing.

[0006] To achieve the above objectives, this application provides a multi-winding CT polarity intelligent pulse testing device, including a control module, and a power supply module, a primary pulse generation module, a secondary sampling module, and a display module respectively connected to the control module;

[0007] The power module is used to provide operating power;

[0008] The primary pulse generation module is connected to the power supply module and is used to output DC pulse current to the primary side of the current transformer under test.

[0009] The secondary sampling module includes at least two secondary sampling units, each of which is independently connected to different secondary windings of the current transformer under test, for synchronously acquiring pulse current signals induced in each winding.

[0010] The control module is connected to the primary pulse generation module and each of the secondary sampling units respectively. It is used to trigger the primary pulse generation module to output DC pulse current, receive the pulse current signals of each of the secondary sampling units in the secondary sampling module, and generate corresponding polarity determination results according to the polarity direction of each pulse current signal.

[0011] The display module is used to simultaneously display the polarity determination results corresponding to all secondary windings.

[0012] Furthermore, in some embodiments of this application, the power module includes a rechargeable lithium battery and a charging management circuit, wherein the charging management circuit includes a charging input interface, a power control unit, and a power switch button;

[0013] The charging input interface is directly connected in parallel to both ends of the rechargeable lithium battery for connecting to an external charger.

[0014] The power control unit is connected between the rechargeable lithium battery, the primary pulse generation module, and the control module, and is used to control the connection or disconnection of power supply.

[0015] The normally open contact of the power switch button controls the enable terminal of the power control unit, and the normally closed contact of the power switch button is connected to the control module.

[0016] Furthermore, in some embodiments of this application, the primary pulse generation module includes a capacitor charging and discharging unit and a relay switching unit;

[0017] The capacitor charging and discharging unit is connected to the power module through a current-limiting resistor and is used to store electrical energy;

[0018] The relay switching unit is controlled by the control module and is used to release the electrical energy of the capacitor to the primary circuit of the current transformer under test.

[0019] Furthermore, in some embodiments of this application, the capacitor charging and discharging unit further includes a freewheeling protection circuit, wherein the freewheeling protection circuit is formed by a diode connected in reverse parallel across the primary coil of the current transformer under test.

[0020] Furthermore, in some embodiments of this application, each of the secondary sampling units includes a current-to-voltage conversion circuit, a signal conditioning circuit, and a polarity determination circuit;

[0021] The current-to-voltage conversion circuit is used to convert the induced pulse current signal into a voltage signal;

[0022] The signal conditioning circuit is connected to the current-to-voltage conversion circuit and is used to amplify and shape the voltage signal;

[0023] The polarity determination circuit is connected to the signal conditioning circuit and is used to output a digital signal representing the polarity direction to the control module.

[0024] Furthermore, in some embodiments of this application, the polarity determination circuit includes a positive polarity detection path and a negative polarity detection path connected in parallel, for outputting a subtractive polarity or an additive polarity identification signal, respectively.

[0025] Furthermore, in some embodiments of this application, each of the secondary sampling units further includes an input protection circuit, wherein the input protection circuit consists of a clamping diode connected in parallel to the input terminal of the signal conditioning circuit to limit the input voltage within a preset voltage range.

[0026] Furthermore, in some embodiments of this application, the control module includes a master controller and a slave controller, and the master controller and the slave controller communicate through an optocoupler isolation circuit;

[0027] The main controller is used to control the triggering and power management of the primary pulse generation module;

[0028] The slave controller is used to process the pulse current signals of each of the secondary sampling units and generate polarity determination results.

[0029] Furthermore, in some embodiments of this application, the display module includes a liquid crystal display screen and an indicator light group;

[0030] The liquid crystal display screen is used to display the polarity results of each winding in text.

[0031] The indicator light group is connected to the sampling channel of each of the secondary sampling units, and each indicator light group includes an increasing polarity indicator light and a decreasing polarity indicator light.

[0032] This application also provides an electronic device, including the multi-winding CT polarity intelligent pulse testing device as described above.

[0033] Implementing the embodiments of this application has the following beneficial effects:

[0034] As described above, this application provides a multi-winding current transformer (CT) polarity intelligent pulse testing device and electronic device. The multi-winding CT polarity intelligent pulse testing device includes a control module, and a power supply module, a primary pulse generation module, a secondary sampling module, and a display module, all connected to the control module. The power supply module provides operating power. The primary pulse generation module, connected to the power supply module, outputs a DC pulse current to the primary side of the current transformer under test. The secondary sampling module includes at least two secondary sampling units, each independently connected to different secondary windings of the current transformer under test, for synchronously acquiring the pulse current signals induced by each winding. The control module, connected to the primary pulse generation module and each secondary sampling unit, triggers the primary pulse generation module to output a DC pulse current, receives the pulse current signals from each secondary sampling unit in the secondary sampling module, and generates a corresponding polarity determination result based on the polarity direction of each pulse current signal. The display module simultaneously displays the polarity determination results corresponding to all secondary windings. This application uses a control module to coordinate the operation of each module. It triggers the primary pulse generation module to output a DC pulse current, while multiple independent sampling units of the secondary sampling module synchronously acquire induced pulse current signals from different secondary windings. Based on the signal polarity, a judgment result is generated, and the final result for multiple windings is presented intuitively through the display module. Therefore, this application can efficiently and accurately complete the testing of the polarity of multi-winding CTs, solving the problems of low testing efficiency, insufficient accuracy, and the need for multiple operators in traditional testing methods. It improves testing efficiency and accuracy while reducing the complexity and error risk of manual operation. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a multi-winding CT polarity intelligent pulse testing device in one embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the internal circuit of a multi-winding CT polarity intelligent pulse testing device in one embodiment of this application;

[0037] Figure 3 This is a schematic diagram of the panel structure of a multi-winding CT polarity intelligent pulse testing device in one embodiment of this application.

[0038] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0040] Figure 1 This is a schematic diagram of the structure of a multi-winding CT polarity intelligent pulse testing device according to an embodiment of this application. (Reference) Figure 1 The multi-winding CT polarity intelligent pulse testing device specifically includes a control module 10, and a power supply module 20, a primary pulse generation module 30, a secondary sampling module 40, and a display module 50, all connected to the control module. The control module 10 acts as the core, connecting and managing the other modules, while the power supply module 20 provides power. The primary pulse generation module 30, controlled by the control module, outputs a DC pulse current to the primary side of the CT under test. The secondary sampling module 40 contains multiple secondary sampling units, each independently connected to different secondary windings of the CT under test, synchronously acquiring the induced pulse current signal and transmitting it to the control module 10. After receiving the signal, the control module 10 generates a determination result based on the polarity direction of the pulse current signal, and the display module 50 then visually displays the polarity determination results of all secondary windings.

[0041] Power module 20 is used to provide operating power;

[0042] Specifically, the power module 20, as the core of the power supply for the entire device, provides a stable power source for other modules. In this embodiment, the power module 20 uses a rechargeable lithium battery as its power source, and charging control is achieved through a charging management circuit, ensuring the stability and reliability of the power supply.

[0043] A primary pulse generation module 30 is connected to the power supply module and is used to output DC pulse current to the primary side of the current transformer under test.

[0044] Specifically, the primary pulse generation module 30 is responsible for generating and outputting a DC pulse current. The generated pulse current passes through the primary side of the CT under test, providing an excitation signal for secondary sampling. The primary pulse generation module 30 typically consists of a capacitor charging and discharging unit and a relay switching unit. The capacitor charging and discharging unit stores electrical energy, while the relay switching unit, under the command of the control module, releases the energy of the capacitor to the primary side circuit of the CT under test, generating the required pulse current.

[0045] The secondary sampling module 40 includes at least two secondary sampling units, each of which is independently connected to different secondary windings of the current transformer under test, for synchronously acquiring the pulse current signals induced in each winding.

[0046] Specifically, the secondary sampling module 40 is used to sample the secondary windings of the CT under test, acquiring the induced pulse current signals of each winding. Each secondary sampling unit includes a current-to-voltage conversion circuit, a signal conditioning circuit, and a polarity determination circuit. The current-to-voltage conversion circuit converts the induced pulse current signal into a voltage signal, the signal conditioning circuit amplifies and shapes the voltage signal, and the polarity determination circuit determines the polarity direction based on the processed signal and outputs the result to the control module in the form of a digital signal. The independent connection of the secondary sampling units ensures the synchronization and accuracy of sampling for each winding.

[0047] The control module 10 is connected to the primary pulse generation module and each secondary sampling unit respectively. It is used to trigger the primary pulse generation module to output DC pulse current, receive the pulse current signals of each secondary sampling unit in the secondary sampling module, and generate the corresponding polarity determination result according to the polarity direction of each pulse current signal.

[0048] Specifically, the control module 10, acting as the command center of the entire device, bears the crucial responsibility of coordinating the work of various modules and processing data. The control module 10 triggers the primary pulse generator to output a pulse current and receives the sampling results from the secondary sampling module. By analyzing the polarity direction of the pulse current signal, it generates the corresponding polarity determination result. The control module 10 is connected to the primary pulse generator and each secondary sampling unit, realizing the control and data processing of the entire testing process. By triggering the primary pulse generator to output a DC pulse current, it provides an excitation signal for the secondary sampling. Simultaneously, the control module receives the pulse current signals from each secondary sampling unit in the secondary sampling module and generates the corresponding polarity determination result based on the polarity direction of each pulse current signal. This intelligent control method not only improves the accuracy of the test but also greatly simplifies the operation process and reduces human error.

[0049] Display module 50 is used to simultaneously display the polarity determination results of all secondary windings;

[0050] Specifically, the display module 50 is used to present the polarity determination results to the user in an intuitive way, making it easy to observe and record. The display module typically includes an LCD screen and an indicator light group. The LCD screen displays the polarity results of each winding in text, while the indicator light group corresponds to the sampling channel of each secondary sampling unit, intuitively displaying the polarity determination results through indicator lights of different colors or states.

[0051] This embodiment consists of a control module, a power supply module, a primary pulse generation module, a secondary sampling module, and a display module. Each module has a clear division of labor and works collaboratively to form a highly integrated testing system. This allows the device to connect multiple windings simultaneously and perform tests concurrently, avoiding the significant time and manpower required for testing each winding individually in traditional methods, thus improving testing efficiency. The primary pulse generation module outputs a stable DC pulse current to the primary side of the CT under test, providing an accurate excitation signal for secondary sampling, ensuring the stability of the pulse current and the accuracy of the test. Each secondary sampling unit is independently connected to different secondary windings of the CT under test, enabling synchronous acquisition of the pulse current signals induced by each winding, ensuring the accuracy of signal acquisition and anti-interference capability, and improving the reliability of polarity determination.

[0052] Furthermore, in some embodiments, the power module 10 includes a rechargeable lithium battery and a charging management circuit, the charging management circuit including a charging input interface, a power control unit, and a power switch button.

[0053] The charging input interface is directly connected in parallel to both ends of the rechargeable lithium battery for connecting to an external charger.

[0054] Specifically, the rechargeable lithium battery is connected to an external charger via the charging input interface in the charging management circuit. The charging input interface is directly connected in parallel across the two ends of the rechargeable lithium battery to charge it. The charging management circuit controls the charging process, ensuring safe and stable charging of the lithium battery. As the energy core of the entire device, the rechargeable lithium battery provides a 12.6V operating power supply. Its large capacity (e.g., a nominal capacity of 10Ah) ensures that the device can operate continuously for more than 24 hours after a single full charge, meeting the needs of long-term field testing. The charging input interface connects to an external charger, introducing external power (e.g., DC 12.6V·3A) into the device to charge the rechargeable lithium battery.

[0055] The power control unit is connected between the rechargeable lithium battery and the primary pulse generation module and control module, and is used to control the connection or disconnection of power supply.

[0056] Specifically, the power control unit is connected between the rechargeable lithium battery and the primary pulse generation module and control module. It is responsible for controlling the power supply, thus playing a power management role. By controlling the power supply, the power control unit ensures that the power is cut off when the device is not in use, reducing power consumption and protecting the lithium battery from over-discharge. During testing, it is responsible for providing a stable power supply to the primary pulse generation module and control module.

[0057] The normally open contact of the power switch button controls the enable terminal of the power control unit, and the normally closed contact of the power switch button connects to the control module.

[0058] Specifically, the normally open contact of the power switch button is connected to the enable terminal of the power control unit to control its startup; the normally closed contact is connected to the control module to transmit the power switch status information, enabling the control module to coordinate the operation of the entire device. The power switch button is used for manual control of the device's power switch. Pressing and holding the power switch button closes its normally open contact, energizing the power control unit and powering on the device; the normally closed contact opens, sending a signal to the control module to initiate its operation. In this way, the power switch button controls the device's startup and shutdown.

[0059] This embodiment utilizes a rechargeable lithium battery as its core energy source, along with a charging management circuit and a power switch button. The power module provides stable and reliable power support for the multi-winding CT polarity intelligent pulse testing device. The large capacity of the rechargeable lithium battery ensures long-term battery life, meeting the needs of extended field testing. Furthermore, the charging management circuit not only protects the lithium battery but also achieves efficient power management and distribution through the power control unit, ensuring stable operation of the device during testing. The power switch button simplifies user operation, making starting and stopping the device more convenient.

[0060] Furthermore, in some embodiments, the primary pulse generation module includes a capacitor charging / discharging unit and a relay switching unit;

[0061] The capacitor charging and discharging unit is connected to the power module through a current-limiting resistor and is used to store electrical energy;

[0062] Specifically, the capacitor charging / discharging unit is connected to the power module via a current-limiting resistor, which controls the charging current to ensure safe and stable charging of the capacitor. When the device is in standby mode, the capacitor charging / discharging unit draws and stores electrical energy from the power module through the current-limiting resistor. This acts like an energy storage container, preparing for the generation of a pulse current. When the relay switch unit closes, the capacitor begins to discharge. Because the capacitor releases a large amount of electrical energy in a short time, a DC pulse current is generated in the primary circuit of the CT under test. This pulse current is the key excitation signal for testing the polarity of the CT.

[0063] The relay switching unit is controlled by the control module and is used to release the energy of the capacitor to the primary circuit of the current transformer under test.

[0064] Specifically, the relay switching unit, controlled by the control module, is connected between the capacitor charging / discharging unit and the primary circuit of the CT under test. When the control module sends a trigger signal, the relay switching unit activates, releasing the electrical energy stored in the capacitor charging / discharging unit into the primary circuit of the CT under test, forming a pulse current. The relay switching unit is controlled by the control module. The relay will only close when the control module sends a trigger signal, allowing the capacitor to discharge and generate a pulse current. This ensures precise control over the generation of the pulse current, synchronizing it with the overall operation of the testing device. When not triggered, the relay switching unit is in the open state, isolating the capacitor charging / discharging unit from the primary circuit of the CT under test. This ensures the safety and stability of the device in standby mode, preventing energy loss due to continuous capacitor discharge or unnecessary impact on the CT under test.

[0065] This embodiment achieves efficient and controllable pulse current output from the primary pulse generation module by introducing a capacitor charging / discharging unit and a relay switching unit. The capacitor charging / discharging unit stores sufficient electrical energy and releases it rapidly under the control of the relay switching unit, forming a pulse current that meets the test requirements. This not only ensures that the amplitude and duration of the pulse current meet the needs of CT polarity testing, but also improves the safety and reliability of the testing process through the control of the relay, effectively avoiding false triggering or abnormal pulse current. Simultaneously, the current-limiting resistor further protects the capacitor and the entire circuit, ensuring that the device can stably and accurately complete the multi-winding CT polarity testing task.

[0066] Furthermore, in some embodiments, the capacitor charging and discharging unit also includes a freewheeling protection circuit, which is formed by a diode connected in reverse parallel across the primary coil of the current transformer under test.

[0067] Specifically, in the freewheeling protection circuit, the diode is connected in reverse parallel across the primary coil of the current transformer (CT) under test. The anode of the diode is connected to one end of the CT primary coil, and the cathode is connected to the other end. When the relay switching unit is disconnected, a momentary high-voltage back EMF is generated in the CT primary coil due to the self-inductance effect. This high voltage may damage other components in the circuit, such as capacitors and relays. The diode in the freewheeling protection circuit provides a release path for this momentary high voltage, preventing it from damaging the circuit. Under normal circumstances, the diode is in reverse cutoff mode and does not affect the process of the capacitor discharging into the CT primary coil. However, when the relay is disconnected, the current in the CT primary coil is suddenly interrupted, generating a reverse high voltage. At this time, the diode will conduct in the forward direction, providing a freewheeling path for the current in the CT coil, causing it to gradually decay, thereby reducing the amplitude of the momentary high voltage.

[0068] This embodiment effectively solves the problem of high voltage back EMF that may occur during the single pulse current output process by adding a freewheeling protection circuit. This not only protects key components such as the capacitor charging and discharging unit and the relay switching unit, extending the service life of the device, but also improves the reliability and safety of the entire testing device.

[0069] Furthermore, in some embodiments, each secondary sampling unit includes a current-to-voltage conversion circuit, a signal conditioning circuit, and a polarity determination circuit; these three circuits are connected in sequence, with the output terminal of the current-to-voltage conversion circuit connected to the input terminal of the signal conditioning circuit, and the output terminal of the signal conditioning circuit connected to the input terminal of the polarity determination circuit. Through the above connection method, the pulse current signal can be converted, conditioned, and determined in sequence, and finally output a digital signal representing the polarity direction.

[0070] A current-to-voltage conversion circuit is used to convert an induced pulse current signal into a voltage signal;

[0071] Specifically, the main function of a current-to-voltage conversion circuit is to convert the pulse current signal induced from the secondary winding of the current transformer (CT) under test into a voltage signal. Subsequent signal processing circuits are generally more suitable for processing voltage signals. This conversion can be achieved by using a precision resistor in the circuit. When a pulse current flows through this resistor, a voltage drop is generated across it, which is proportional to the pulse current.

[0072] The signal conditioning circuit, connected to the current-to-voltage conversion circuit, is used to amplify and shape voltage signals;

[0073] Specifically, the signal conditioning circuit amplifies the converted voltage signal to a suitable amplitude for subsequent processing. This is because the converted voltage signal may be very weak and needs to be amplified for accurate processing and analysis. Besides amplification, the signal conditioning circuit may also filter and shape the signal to remove noise and interference, improving signal quality. For example, active devices such as operational amplifiers can be used to achieve signal amplification and shaping. By appropriately selecting the amplifier gain and filtering parameters, the signal processing effect can be optimized.

[0074] The polarity determination circuit, connected to the signal conditioning circuit, is used to output a digital signal representing the polarity direction to the control module.

[0075] Specifically, the polarity determination circuit determines the direction of the pulse current based on the polarity of the conditioned voltage signal and outputs a corresponding digital signal (such as a high or low level) to characterize the polarity direction. This polarity determination can be implemented using a comparator, which compares the conditioned voltage signal with a reference voltage and outputs a corresponding digital signal based on the comparison result. For example, if the conditioned voltage signal is higher than the reference voltage, it is determined to be an increasing polarity; if it is lower than the reference voltage, it is determined to be a decreasing polarity.

[0076] This embodiment achieves efficient and accurate processing of the induced pulse current signal from the CT secondary winding by subdividing the secondary sampling module into a current-to-voltage conversion circuit, a signal conditioning circuit, and a polarity determination circuit. The current-to-voltage conversion circuit ensures the conversion of the signal form, the signal conditioning circuit improves the signal quality and amplitude, and the polarity determination circuit accurately determines the polarity direction of the pulse current. This hierarchical processing design not only improves the accuracy and reliability of signal processing but also allows each functional module to focus more on specific tasks, thereby enhancing the performance of the entire testing device.

[0077] Furthermore, in some embodiments, the polarity determination circuit includes a positive polarity detection path and a negative polarity detection path connected in parallel, for outputting a subtractive polarity or an additive polarity identification signal, respectively.

[0078] Specifically, the polarity determination circuit includes a positive polarity detection path and a negative polarity detection path connected in parallel, both connected between the output of the signal conditioning circuit and the control module. This allows both paths to simultaneously receive the conditioned voltage signal and detect and determine its polarity separately. The positive polarity detection path is specifically used to detect positive polarity. When the conditioned voltage signal indicates that the direction of the pulse current corresponds to positive polarity, the positive polarity detection path is activated. Once positive polarity is detected, the positive polarity detection path outputs a positive polarity indicator signal to the control module, such as a high-level signal or other predefined digital signal. The negative polarity detection path is specifically used to detect negative polarity. When the conditioned voltage signal indicates that the direction of the pulse current corresponds to negative polarity, the negative polarity detection path is activated. Once negative polarity is detected, the negative polarity detection path outputs a negative polarity indicator signal to the control module, such as a low-level signal or other predefined digital signal.

[0079] This embodiment introduces parallel positive and negative polarity detection paths, enabling rapid and accurate determination of the polarity of the CT secondary winding induced pulse current signal. This allows the polarity determination circuit to detect both polarity conditions simultaneously, improving the efficiency and accuracy of the determination. Furthermore, the parallel structure ensures that the two polarity detections do not interfere with each other, enhancing the reliability of the determination and effectively avoiding misjudgments or missed judgments.

[0080] Furthermore, in some embodiments, each secondary sampling unit also includes an input protection circuit, which consists of a clamping diode connected in parallel to the input terminal of the signal conditioning circuit to limit the input voltage within a preset voltage range.

[0081] Specifically, each secondary sampling unit also includes an input protection circuit. The clamping diode in this circuit is connected in parallel to the input of the signal conditioning circuit; that is, the two ends of the clamping diode are connected to the positive and negative input terminals of the signal conditioning circuit, respectively. The main function of the input protection circuit is to prevent excessive input voltage from damaging the signal conditioning circuit. During CT polarity testing, abnormal pulse current signals may occur, causing voltages exceeding the normal range at the input of the signal conditioning circuit. The clamping diode limits the input voltage to a preset safe voltage range, thus protecting the signal conditioning circuit from damage. Under normal operating conditions, the clamping diode is in the off state and does not affect the normal input voltage of the signal conditioning circuit. However, when the input voltage exceeds the clamping diode's withstand voltage, the clamping diode quickly conducts, clamping the overvoltage to a safe voltage value, typically the diode's reverse breakdown voltage. Thus, even if an overvoltage occurs at the input, it will not exceed the safe range set by the clamping diode.

[0082] This embodiment effectively prevents damage to the signal conditioning circuit caused by overvoltage by adding an input protection circuit, which not only improves the reliability and stability of the secondary sampling unit, but also enhances the robustness of the entire test device when facing abnormal signals.

[0083] Furthermore, in some embodiments, the control module includes a master controller and a slave controller, which communicate with each other through an optocoupler isolation circuit to achieve electrical isolation and ensure safe and reliable signal transmission between the master controller and the slave controller.

[0084] The main controller is used to control the triggering and power management of the primary pulse generation module;

[0085] Specifically, the main controller is connected to the primary pulse generator module and the power supply module, and is responsible for controlling the triggering of the primary pulse generator module and the power management of the entire device. The main controller is responsible for triggering the primary pulse generator module, that is, sending a signal at the start of the test to start the primary pulse generator module to output a DC pulse current to the primary side of the CT under test. The main controller is also responsible for the power management of the entire device, including controlling the on / off state of the power supply module, and triggering an automatic shutdown function when the battery power is low or there has been no operation for a long time, in order to save energy and protect the battery.

[0086] The controller processes the pulse current signals of each secondary sampling unit and generates polarity determination results.

[0087] Specifically, the controller is connected to each secondary sampling unit and is responsible for receiving and processing the pulse current signals from the secondary sampling module, and generating polarity determination results. The main responsibility of the controller is to receive pulse current signals from each secondary sampling unit of the secondary sampling module, and process and analyze these signals. Based on the processed signals, the controller determines the polarity direction of each secondary winding and generates the corresponding polarity determination result. These results are then transmitted to the display module for display.

[0088] Furthermore, the main function of the optocoupler isolation circuit is to provide electrical isolation between the master controller and the slave controller, preventing high voltage or noise interference from being transmitted from one module to another. Simultaneously, the optocoupler isolation circuit also allows signal transmission between the master and slave controllers, ensuring they can work together to achieve effective control and management of the entire test setup.

[0089] This embodiment improves the control accuracy and signal processing capabilities of the entire testing device through the subdivision and optimization of the control module. The division of labor and cooperation between the master and slave controllers enables the device to efficiently manage power supply, trigger pulse output, and process complex signals. The application of optocoupler isolation circuitry enhances the device's anti-interference capability and safety, ensuring stable and reliable operation in complex power system environments. This design not only improves the device's performance and reliability but also provides a solid foundation for further accurate testing of multi-winding CT polarity.

[0090] Furthermore, in some embodiments, the display module includes a liquid crystal display screen and an indicator light group;

[0091] An LCD screen is used to display the polarity results of each winding in text.

[0092] Specifically, the LCD screen is connected to the control module via a data bus and control signal lines, receiving display data and control commands from the control module. The LCD screen can display the polarity determination results of each secondary winding in detail, either in text or graphics. This display method is not only intuitive but also provides more information, such as the specific polarity direction, test time, and battery level. The LCD screen can also display operation prompts and error messages to help users operate the testing device more effectively and improve the user experience.

[0093] The indicator light group is connected to the sampling channel of each secondary sampling unit. Each indicator light group includes an increasing polarity indicator light and a decreasing polarity indicator light.

[0094] Specifically, the indicator light group is connected to the control module via a drive circuit. The control module controls the on / off state of the corresponding indicator light based on the polarity determination result. The indicator light group corresponds to the sampling channel of each secondary sampling unit, and each group includes an indicator light for increasing polarity and an indicator light for decreasing polarity. By observing the on / off state of the indicator lights, users can quickly and intuitively understand the polarity of each secondary winding. The indicator light group can also be used to display other status information of the device, such as power status, test in progress, and test completed, further enhancing the user-friendliness of the device.

[0095] This embodiment introduces an LCD screen and indicator lights, enabling the display module to present test results and device status intuitively in multiple ways. The LCD screen provides detailed text or graphic information, suitable for user recording and analysis; the indicator lights quickly convey key information through intuitive light signals, facilitating real-time monitoring during testing. This dual display method not only improves the readability and usability of information but also enhances the user's interactive experience with the device, ensuring users can efficiently and accurately obtain test results, further improving the practicality and convenience of the entire testing device.

[0096] like Figure 2 As shown, this embodiment also provides an internal circuit schematic diagram of a multi-winding CT polarity intelligent pulse testing device, which may specifically include:

[0097] (1) Power supply circuit:

[0098] The 12V power supply from the internal lithium-ion battery is controlled by the power control module. One path is sent to the primary circuit to charge capacitor C1 through resistor R1; another path is sent to the microcontroller MCU1 through a step-down voltage regulator circuit; and the third path is sent to the secondary circuit through a DC / DC isolation module.

[0099] Pressing the power switch button SB1 closes its normally open contact, energizing the power control module and powering on the microcontroller MCU1. The normally closed contact of SB1 then opens, sending a signal to MCU1. MCU1's power control signal keeps the power control module powered on, thus powering on the entire device. To manually power off, press and hold SB1. MCU1 receives a power-off command, and its power control signal disconnects the power control module, shutting down the entire device. When the battery level drops below 10% or after 30 minutes of inactivity, MCU1's power control signal disconnects the power control module, automatically powering off the entire device. The aviation socket P is connected directly in parallel with the battery; an external lithium battery charger is required for charging.

[0100] (2) Primary loop:

[0101] After power is connected, the battery charges capacitor C1 through resistor R1. When test button SB2 is pressed, MCU1 outputs an action signal to the relay drive circuit, relay K actuates, and capacitor C1 discharges through resistor R2 and the primary circuit of the CT under test. The resistance of R2 is 2Ω, so the maximum instantaneous current on the primary side of the CT is approximately I1 = 12V / 2Ω = 6A. Due to the resistance of the output wire, plus the resistance of the CT primary circuit, the maximum instantaneous current on the primary side of the CT is generally less than 6A. Diode D1 is connected in reverse parallel with the CT primary coil. It is cut off when the CT is charging. When K returns, because the CT has inductance, D1 is used to provide freewheeling current to the CT to avoid generating high voltage back EMF. When relay K returns, the primary terminals of the CT are all grounded. The communication signal between the primary circuit MCU1 and the secondary circuit MCU2 is used for the test start signal and the battery level indication signal. This communication signal is optocoupled and isolated.

[0102] (3) Secondary circuit:

[0103] The secondary circuit mainly consists of 6 identical circuits. The following explanation uses the first circuit as an example:

[0104] When relay K is activated, capacitor C1 discharges through the primary coil of CT, generating an instantaneous pulse current in the primary coil. This current induces a pulse current in the secondary coil of CT. This pulse current is converted into a pulse voltage signal after passing through sampling resistor 1R1. It is then amplified by the amplifier circuit and sent to the waveform conversion circuit. There are two waveform conversion circuits: one for converting positive signals (subtraction polarity) and one for converting negative signals (addition polarity). After conversion, it becomes a pulse digital signal and is sent to the microcontroller MCU2.

[0105] The S2 input terminals of the 6 secondary circuits are connected to the common terminal of the secondary circuit power supply.

[0106] (4) MCU2 circuit:

[0107] When test button SB2 is pressed, relay K activates, discharging capacitor C1 in the primary circuit. A pulse current is then applied to the primary side of the CT, inducing a pulse current in the secondary circuit of the CT. This pulse current passes through a sampling resistor, the discharge circuit, and the waveform conversion circuit before being sent to MCU2. When the CT connection is in subtractive polarity, the subtractive polarity waveform conversion circuit outputs a positive signal to MCU2, illuminating and maintaining the subtractive polarity indicator light on MCU2. When the connection is in additive polarity, the additive polarity waveform conversion circuit outputs a negative signal to MCU2, illuminating and maintaining the additive polarity indicator light on MCU2. Simultaneously, MCU2 displays the test result on the screen. Diodes 1D1 and 1D2 are connected in parallel with the secondary circuit. If the secondary circuit input is too high, the diodes conduct, limiting the maximum secondary input voltage to within ±0.7V, protecting the discharge circuit, waveform conversion circuit, and MCU2.

[0108] like Figure 3As shown in the figure, this embodiment also provides a schematic diagram of the panel of a multi-winding CT polarity intelligent pulse testing device, which may specifically include:

[0109] Charging socket: When charging is required, plug the charger's output end into this socket. The maximum charging voltage is 12.6V, and the maximum charging current is 3A. When replacing the charger, it must be of the same specification as this charger.

[0110] Power switch button: When the device is off, press and hold this button for 1 second until the buzzer sounds once and the button indicator light illuminates, indicating that the device is on. When the device is on, press and hold this button for 1 second until the buzzer sounds once and the button indicator light goes out, indicating that the device is off.

[0111] Test button: Simply press the test button, the button indicator light will flash, and after 3 seconds both the polarity indicator light and the display screen will indicate (display) the polarity.

[0112] Grounding terminal: This terminal is connected to the housing and is also connected to the primary output terminal when not under test. If the CT under test has an induced voltage, this terminal should be reliably grounded.

[0113] Primary output terminals: This set of terminals is connected to the primary side of the CT, and all primary sides of the CTs are connected in series.

[0114] Secondary input terminals: This set of terminals connects to the secondary side of the CT.

[0115] Reduced polarity indicator light: When the reduced polarity indicator light is on, it indicates that the polarity of P1 and S1 is reduced. This indicator light will remain on.

[0116] Polarity indicator light: When the polarity indicator light is on, it indicates that P1 and S1 are polarized. This indicator light will remain on.

[0117] Display screen: This display screen shows the test results.

[0118] Battery power indicator: This group of indicator lights has 5 lights, with colors of green (100%, 80%, 60%, 40%) and red (20%).

[0119] In a specific embodiment, the device provided in this embodiment, upon receiving a test command, controls the power supply module to output a DC 12.6V DC pulse test power supply to the primary side of the CT. The current sampling module simultaneously samples the DC pulse induced current of multiple windings (no fewer than four windings) on the secondary side of the CT, and determines the polarity of the secondary circuit wiring of each winding based on the collected DC pulse induced current of each winding. The test results are displayed on an LCD screen and indicator lights. The device uses a built-in lithium battery as its working power source and can operate independently after being disconnected from an AC power source. Its power supply module charges the built-in lithium battery and outputs DC pulse test power according to the device control command. Its input is AC 220V, and its output is DC 12.6V. The device's DC 12.6V DC pulse test power supply interface and the output test cable connector are connected via a plug-in method, and the connector and output test cable connector are designed to prevent mis-plugging. The output test cable uses color coding to distinguish polarity; one end is a mis-plugging connector, and the other end is an alligator clip, facilitating wiring by the tester and ensuring correct wiring. The device's current sampling module can simultaneously sample the DC pulse induced current of multiple windings (no less than four windings) on the secondary side of the CT. Its sampling interface and sampling test lead combination plug are connected via a plug-in method, and each plug and sampling test lead combination plug is designed to prevent mis-plugging. Each sampling test lead is grouped and color-coded to distinguish polarity. One end is a mis-plugging prevention plug, and the other end is a test plug (matching the current test terminal socket) or alligator clip, facilitating wiring for testers and ensuring correct wiring. The device samples DC pulse induced current with a range of 0-1000mA and an accuracy of 1.5 class. The device is lightweight and portable; after charging, it can be used immediately after connecting the wires on-site. No parameter settings are required during testing; pressing the test button automatically completes the test and judgment. The device has a self-holding function for test results; pressing the test button again automatically resets and retests, retaining the new test results, effectively preventing human error or omission during CT polarity testing.

[0120] This embodiment also provides an electronic device, including the multi-winding CT polarity intelligent pulse testing device as described above.

[0121] Compared with existing technologies, the multi-winding CT polarity intelligent pulse testing device provided in this embodiment can simultaneously perform polarity tests on multiple windings. Compared with traditional testing instruments, it can simultaneously test no less than four sets of CT secondary coils, avoiding problems such as frequent switching of dry batteries and time wasted by multiple people working at long distances. It reduces the workload of measuring each winding one by one, saving time and effort, improving accuracy, and shortening the polarity testing time, thereby improving work testing efficiency. The wiring of this testing device is quick and easy. Inspection work that previously required multiple people to complete simultaneously can now be completed by one person independently, eliminating the workload of needing someone to observe the ammeter pointer deflection while disconnecting and connecting the external power supply, thus improving work efficiency.

[0122] The terms "first" and "second" in the above-mentioned modules / units are only used to distinguish different modules / units and are not intended to specify which module / unit has a higher priority or any other limiting meaning. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not necessarily limited to those steps or modules explicitly listed, but may include other steps or modules not explicitly listed or inherent to these processes, methods, products, or devices. The module divisions appearing in this application are merely logical divisions; in actual applications, different division methods may be used.

[0123] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0124] The sequence numbers of the embodiments in this application are merely for description and do not represent the superiority or inferiority of the embodiments. Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases, the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0125] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A multi-winding CT polarity intelligent pulse testing device, characterized in that, It includes a control module, and a power supply module, a primary pulse generation module, a secondary sampling module, and a display module, which are respectively connected to the control module; The power module is used to provide operating power; The primary pulse generation module is connected to the power supply module and is used to output DC pulse current to the primary side of the current transformer under test. The secondary sampling module includes at least two secondary sampling units, each of which is independently connected to different secondary windings of the current transformer under test, for synchronously acquiring pulse current signals induced in each winding. The control module is connected to the primary pulse generation module and each of the secondary sampling units respectively. It is used to trigger the primary pulse generation module to output DC pulse current, receive the pulse current signals of each of the secondary sampling units in the secondary sampling module, and generate corresponding polarity determination results according to the polarity direction of each pulse current signal. The display module is used to simultaneously display the polarity determination results corresponding to all secondary windings.

2. The multi-winding CT polarity intelligent pulse testing device according to claim 1, characterized in that, The power module includes a rechargeable lithium battery and a charging management circuit, the charging management circuit including a charging input interface, a power control unit and a power switch button; The charging input interface is directly connected in parallel to both ends of the rechargeable lithium battery for connecting to an external charger. The power control unit is connected between the rechargeable lithium battery, the primary pulse generation module, and the control module, and is used to control the connection or disconnection of power supply. The normally open contact of the power switch button controls the enable terminal of the power control unit, and the normally closed contact of the power switch button is connected to the control module.

3. The multi-winding CT polarity intelligent pulse testing device according to claim 1, characterized in that, The primary pulse generation module includes a capacitor charging and discharging unit and a relay switching unit; The capacitor charging and discharging unit is connected to the power module through a current-limiting resistor and is used to store electrical energy; The relay switching unit is controlled by the control module and is used to release the electrical energy of the capacitor to the primary circuit of the current transformer under test.

4. The multi-winding CT polarity intelligent pulse testing device according to claim 3, characterized in that, The capacitor charging and discharging unit also includes a freewheeling protection circuit, which consists of a diode connected in reverse parallel across the primary coil of the current transformer under test.

5. The multi-winding CT polarity intelligent pulse testing device according to claim 1, characterized in that, Each of the aforementioned secondary sampling units includes a current-to-voltage conversion circuit, a signal conditioning circuit, and a polarity determination circuit; The current-to-voltage conversion circuit is used to convert the induced pulse current signal into a voltage signal; The signal conditioning circuit is connected to the current-to-voltage conversion circuit and is used to amplify and shape the voltage signal; The polarity determination circuit is connected to the signal conditioning circuit and is used to output a digital signal representing the polarity direction to the control module.

6. The multi-winding CT polarity intelligent pulse testing device according to claim 5, characterized in that, The polarity determination circuit includes a positive polarity detection path and a negative polarity detection path connected in parallel, which are used to output a subtractive polarity or an additive polarity identification signal, respectively.

7. The multi-winding CT polarity intelligent pulse testing device according to claim 5, characterized in that, Each of the secondary sampling units also includes an input protection circuit, which consists of a clamping diode connected in parallel to the input terminal of the signal conditioning circuit to limit the input voltage within a preset voltage range.

8. The multi-winding CT polarity intelligent pulse testing device according to claim 1, characterized in that, The control module includes a master controller and a slave controller, which communicate with each other via an optocoupler isolation circuit. The main controller is used to control the triggering and power management of the primary pulse generation module; The slave controller is used to process the pulse current signals of each of the secondary sampling units and generate polarity determination results.

9. The multi-winding CT polarity intelligent pulse testing device according to claim 1, characterized in that, The display module includes an LCD screen and an indicator light group; The liquid crystal display screen is used to display the polarity results of each winding in text. The indicator light group is connected to the sampling channel of each of the secondary sampling units, and each indicator light group includes an increasing polarity indicator light and a decreasing polarity indicator light.

10. An electronic device, characterized in that, Including the multi-winding CT polarity intelligent pulse testing device as described in any one of claims 1-9.

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