Multi-channel intelligent contact resistance testing device and method

Abstract

This invention provides a multi-channel intelligent contact resistance testing device and method. The intelligent contact resistance testing device integrates multiple different types of resistance testing channels, including continuity testing channels, static resistance testing channels, and dynamic resistance testing channels. The device includes: a host control module for receiving channel test parameters of contact resistance and generating channel selection test commands based on the channel test parameters; a multi-channel switching module for switching to the corresponding type of target test channel based on the channel selection test commands; a resistance measurement module for applying a corresponding type of current according to the type of target test channel, acquiring the voltage of the target test channel, and obtaining the resistance value based on the voltage and current; and a signal processing module for noise reduction processing of the resistance value to obtain the target resistance value and evaluate the changing trend of the target resistance value. This invention solves the problems of low testing efficiency, missing dynamic data, and accumulation of human error in traditional methods, and eliminates the subjective bias of manual interpretation.

Description

Technical Field

[0001] This invention relates to the field of resistance testing technology for wind power generation equipment, and in particular to a multi-channel intelligent contact resistance testing device and method. Background Technology

[0002] In the field of wind power equipment testing, accurate measurement of contact resistance is crucial for ensuring the reliable operation of key components such as pitch systems. Traditional testing methods mainly rely on manual point-by-point testing using micro-ohmmeters or high-precision resistance testers, or on recording dynamic resistance values ​​using a rotating test bench.

[0003] However, the above methods have obvious limitations: First, single-channel testing is inefficient, and manual operation is easily affected by differences in skill levels, making it difficult to standardize test results; second, existing equipment lacks high-speed data acquisition capabilities and cannot capture transient changes in dynamic resistance in real time, which may miss key fault characteristics; in addition, the testing process relies on manual intervention and cannot achieve automated calibration, data analysis and fault early warning, making it difficult to meet the wind power industry's demand for efficient and intelligent testing. Summary of the Invention

[0004] This invention provides a multi-channel intelligent contact resistance testing device and method to solve the technical problem of low resistance detection efficiency in wind power generation equipment in the prior art.

[0005] On one hand, the present invention provides a multi-channel intelligent contact resistance testing device, which integrates multiple different types of resistance testing channels, including a continuity testing channel, a static resistance testing channel, and a dynamic resistance testing channel. The device includes:

[0006] The host control module is used to receive the channel test parameters of the contact resistance and generate a channel selection test command based on the channel test parameters.

[0007] The multi-channel switching module switches to the corresponding target test channel based on the channel selection test command.

[0008] The resistance measurement module applies a current of the corresponding type according to the type of the target test channel, and acquires the voltage of the target test channel, and obtains the resistance value based on the voltage and the current;

[0009] The signal processing module performs noise reduction processing on the resistance value to obtain the target resistance value and evaluates the changing trend of the target resistance value.

[0010] According to the present invention, a multi-channel intelligent contact resistance testing device is provided, wherein the multi-channel switching module includes:

[0011] The relay array unit is a multi-channel matrix structure that supports at least 32 four-wire channel switching and is used to switch to the corresponding target test channel according to the channel selection test command.

[0012] The channel status feedback unit is used to provide real-time feedback on the conduction status of the target test channel to the upper control module; wherein, the conduction status includes conduction, short circuit and open circuit.

[0013] According to the present invention, a multi-channel intelligent contact resistance testing device is provided, wherein the resistance measurement module includes:

[0014] A current source unit is used to apply current to the target test channel;

[0015] A voltage acquisition unit is used to acquire the voltage across the target test channel.

[0016] The calculation unit calculates the resistance value of the target test channel based on the voltage and the current.

[0017] According to the present invention, a multi-channel intelligent contact resistance testing device is provided, wherein the signal processing module includes:

[0018] The noise reduction unit is used to filter the resistor values ​​and output the filtered target resistor values.

[0019] The trend analysis unit is used to determine the fluctuation range, standard deviation, and resistance change slope of the target resistance value, and to generate the change trend of the target resistance value based on the fluctuation range, the standard deviation, and the resistance change slope.

[0020] According to the present invention, a multi-channel intelligent contact resistance testing device is provided, wherein the upper control module includes:

[0021] A parameter configuration unit is used to receive the channel test parameters input by the user;

[0022] The instruction generation unit is used to generate the channel selection test instruction based on the channel test parameters.

[0023] According to the present invention, a multi-channel intelligent contact resistance testing device is provided, wherein the current source unit adopts closed-loop feedback control, comprising:

[0024] A PID controller is used to dynamically adjust the output current.

[0025] Low-temperature drift reference voltage source provides a current setting reference;

[0026] The current sampling circuit monitors the output current in real time and feeds it back to the PID controller.

[0027] According to the present invention, a multi-channel intelligent contact resistance testing device is provided, wherein the voltage acquisition unit adopts a differential amplifier circuit.

[0028] According to the present invention, a multi-channel intelligent contact resistance testing device is provided, wherein the noise reduction unit selects a noise reduction method according to the type of the target test channel, specifically including:

[0029] For the dynamic resistance test channel, the Kalman filter algorithm is used, the noise covariance matrix is ​​dynamically adjusted according to the equipment speed, and the filter window length is adaptively set according to the sampling frequency.

[0030] For the static resistance test channel, a moving average filtering algorithm is used, with the filtering window length matched to the sampling frequency;

[0031] For continuity test channels, the resistance status is directly determined using a threshold comparison method.

[0032] According to the present invention, a multi-channel intelligent contact resistance testing device is provided, wherein the trend analysis unit fits the resistance-time curve by least squares method and calculates the fluctuation range, standard deviation and slope of the target resistance value as the evaluation result of the change trend.

[0033] On the other hand, the present invention also provides a multi-channel intelligent contact resistance testing method, wherein the method is applied to the multi-channel intelligent contact resistance testing device described in any of the above claims, and the method includes:

[0034] Receive channel test parameters for contact resistance and generate channel selection test instructions based on the channel test parameters;

[0035] Based on the channel selection test command, switch to the target test channel of the corresponding type;

[0036] According to the type of the target test channel, apply a current of the corresponding type and collect the voltage of the target test channel, and obtain the resistance value based on the voltage and the current;

[0037] The resistance value is subjected to noise reduction processing to obtain the target resistance value, and the changing trend of the target resistance value is evaluated.

[0038] The present invention provides a multi-channel intelligent contact resistance testing device and method. A host control module receives channel test parameters for contact resistance and generates channel selection test commands based on these parameters. A multi-channel switching module switches to the corresponding target test channel based on the channel selection test commands. A resistance measurement module applies a current of the corresponding type according to the type of the target test channel and collects the voltage of the target test channel, obtaining the resistance value based on the voltage and current. A signal processing module performs noise reduction processing on the resistance value to obtain the target resistance value and evaluates the changing trend of the target resistance value. This achieves automated testing of multi-dimensional contact resistance performance, solving the problems of low testing efficiency, missing dynamic data, and accumulated human error in traditional methods. It also eliminates subjective bias in manual interpretation and provides a quantitative basis for equipment status assessment. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 This is one of the structural schematic diagrams of the multi-channel intelligent contact resistance testing device provided in the embodiments of the present invention;

[0041] Figure 2 This is a second schematic diagram of the structure of the multi-channel intelligent contact resistance testing device provided in this embodiment of the invention;

[0042] Figure 3 This is a schematic diagram of the startup interface of the multi-channel intelligent contact resistance testing device provided in this embodiment of the invention;

[0043] Figure 4 This is a schematic diagram of the parameter setting interface of the multi-channel intelligent contact resistance testing device provided in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the test interface of the multi-channel intelligent contact resistance testing device provided in an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of the data query interface of the multi-channel intelligent contact resistance testing device provided in this embodiment of the invention;

[0046] Figure 7 This is a flowchart illustrating the multi-channel intelligent contact resistance testing method provided in this embodiment of the invention.

[0047] Figure 8This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0049] Figure 1 This is one of the structural schematic diagrams of the multi-channel intelligent contact resistance testing device provided in this embodiment of the invention. The intelligent contact resistance testing device (hereinafter referred to as the tester) integrates multiple different types of resistance testing channels, including continuity testing channels, static resistance testing channels (when the equipment is stationary, such as without movement or vibration), and dynamic resistance testing channels (when the equipment is in motion, such as rotating, vibrating, or experiencing current switching). The intelligent contact resistance testing device is suitable for applications requiring testing of the electrical performance indicators of the contact resistance of wind power equipment during production, inspection, and maintenance.

[0050] The intelligent contact resistance testing device adopts a portable carrying case design (e.g., 400mm×260mm×150mm), with a built-in modular mounting slot. A lightweight aluminum alloy frame secures the mounting panel, computer, and core modules of the testing host. The panel is equipped with two JY27466T23F35SN aviation connectors as test output interfaces for connecting adapter cables, adapting to contact resistance devices with different interfaces. The overall layout and panel arrangement are as follows. Figure 2 As shown, the intelligent contact resistance testing device includes test port 151, test port 2 152, probe interface 153, DC charging port 154, power switch 155, power indicator 156, keyboard interface 157, mouse interface 158, and network port 159. The functional units of the tester adopt a modular design, allowing for individual replacement and updates. All units are relatively independent and do not affect each other. In case of a fault at the testing site, the faulty unit can be easily removed and a spare inserted. Each module is independently calibrated; therefore, replacing a module does not require recalibrating the entire intelligent contact resistance testing device.

[0051] See Figure 1 The multi-channel intelligent contact resistance testing device 10 includes a host control module 110, a multi-channel switching module 120, a resistance measurement module 130, and a signal processing module 140.

[0052] The host control module 110 is used to receive the channel test parameters of the contact resistance and generate channel selection test commands based on the channel test parameters.

[0053] Specifically, the upper-level control module 110 refers to the core control unit that configures test parameters. It can be implemented using an industrial-grade embedded processor to convert user-input test requirements into executable channel control instructions.

[0054] The multi-channel switching module 120 switches to the target test channel of the corresponding type based on the channel selection test command.

[0055] Specifically, the multi-channel switching module 120 refers to the hardware unit that realizes physical channel switching. It can be implemented using a relay array structure and completes the fast switching of four-wire channels through matrix coding technology.

[0056] The resistance measurement module 130 applies a current of the corresponding type according to the type of the target test channel, and acquires the voltage of the target test channel to obtain the resistance value based on the voltage and current.

[0057] Specifically, the resistance measurement module 130 refers to the functional unit that performs electrical measurements. It can be implemented by combining a constant current source and a differential amplifier circuit, and the interference of wire resistance is eliminated by using a four-wire measurement method.

[0058] The signal processing module 140 performs noise reduction processing on the resistance value to obtain the target resistance value and evaluates the changing trend of the target resistance value.

[0059] Specifically, the signal processing module 140 refers to the data analysis unit, which can be implemented using digital filtering algorithms and trend analysis algorithms to extract effective resistance characteristics and evaluate performance stability.

[0060] In this embodiment, the upper-level control module 110 receives the channel test parameters of the contact resistance and generates a channel selection test command based on the channel test parameters; the multi-channel switching module 120 switches to the target test channel of the corresponding type based on the channel selection test command; the resistance measurement module 130 applies the corresponding type of current according to the type of the target test channel and collects the voltage of the target test channel, and obtains the resistance value based on the voltage and current; the signal processing module 140 performs noise reduction processing on the resistance value to obtain the target resistance value and evaluates the changing trend of the target resistance value, thereby realizing automated testing of multi-dimensional performance of contact resistance, solving the problems of low testing efficiency, lack of dynamic data and accumulation of human error in traditional methods, eliminating the subjective bias of manual interpretation, and providing a quantitative basis for equipment status assessment.

[0061] In one embodiment of this specification, the multi-channel switching module 120 includes a relay array unit 121 and a channel status feedback unit 122.

[0062] The relay array unit 121 is a multi-channel matrix structure that supports at least 32 four-wire channel switching, used to switch to the corresponding target test channel according to the channel selection test command;

[0063] Specifically, the multi-channel matrix structure uses 32 measurement points as one array, expanding to form a 96-channel matrix array. The relay array unit 121 refers to the hardware component that enables channel switching through the multi-channel matrix structure. It can be implemented using industrial-grade electromagnetic relays or solid-state relay arrays, with dynamic channel allocation achieved through matrix encoding technology. This unit eliminates the influence of wire resistance on the measurement through a four-wire connection, ensuring the independence and integrity of the signal path during switching. The four-wire connection allows for resistance measurement using the Kelvin bridge test method, employing high-precision AD+ automatic range switching technology to ensure accuracy for micro-resistance measurements even at low current. When the resistance value being measured is small, this testing method can obtain very accurate test results. This testing method utilizes direct voltage reading from both ends of the resistor being measured, eliminating errors in test wire connection, especially when measuring short cable lengths, and compensating for the internal resistance of the tester.

[0064] The channel status feedback unit 122 is used to provide real-time feedback on the conduction status of the target test channel to the upper control module 110; wherein, the conduction status includes conduction, short circuit and open circuit.

[0065] Specifically, the channel status feedback unit 122 refers to a module that monitors the electrical status of the channel in real time. It can be implemented using an optocoupler isolation circuit combined with a voltage comparator, determining the continuity, short circuit, or open circuit status by collecting the voltage difference across the channel. This unit uploads the status information in real time via a digital signal transmission protocol, providing closed-loop feedback on the channel health status to the upper control module 110. Incorrect wiring (i.e., wiring errors, such as cross-connections between channels) constitutes an abnormal continuity state for the continuity test channel, specifically categorized as follows: If the incorrect wiring forms a low-resistance path (e.g., cross-contact between two channel wires), it is judged as a short circuit (resistance < 10mΩ, continuity test threshold). If the incorrect wiring causes an open circuit (e.g., wires not connected or poor contact), it is judged as an open circuit (resistance > 1kΩ, open circuit threshold). Critical situations (e.g., contact resistance between 1mΩ and 100mΩ): judged as critical poor contact (abnormal state).

[0066] In this embodiment, the relay array unit 121 establishes a signal path topology network through a multi-path matrix structure. After receiving a channel selection command, it controls the closure of relays at specific row and column intersections to form a target test channel. The four-wire connection method separates the current application path from the voltage acquisition path, avoiding measurement errors introduced by contact resistance. The channel status feedback unit 122 performs status detection after each channel switch, determining the conduction status by comparing a preset threshold with the real-time voltage value. For example, when the detected voltage is lower than the short-circuit threshold, it is determined to be a short-circuit state; when it is higher than the open-circuit threshold, it is determined to be an open-circuit state. The status information is transmitted to the upper control module 110 through an isolated communication interface, triggering channel reselection or test termination operations under abnormal conditions.

[0067] In some other solutions, multi-channel test equipment uses a single-channel relay sequential switching method. The switching speed is limited by the mechanical contact action time and lacks a real-time status feedback mechanism. This application achieves parallel channel control through a matrix relay array, reducing the single switching time to the millisecond level. At the same time, it forms a closed-loop control through a four-wire connection and status feedback mechanism, avoiding the accumulation of test errors caused by poor contact or channel failure. This achieves high-speed and high-reliability channel switching control in multi-channel testing, solving the problems of low test efficiency and misjudgment caused by mechanical delay and lack of status monitoring.

[0068] In one embodiment of this specification, the resistance measurement module 130 includes a current source unit 131, a voltage acquisition unit 132, and a calculation unit 133.

[0069] Current source unit 131 is used to apply current to the target test channel;

[0070] Specifically, the current source unit 131 refers to a circuit module that can output a stable test current. It can be implemented by using closed-loop feedback control combined with a low-temperature drift reference voltage source. By monitoring the output current in real time and dynamically adjusting it, the current value applied to the channel under test is ensured to be accurate and controllable, avoiding measurement errors caused by temperature drift or load changes.

[0071] The voltage acquisition unit 132 is used to acquire the voltage at both ends of the target test channel;

[0072] Specifically, the voltage acquisition unit 132 refers to the circuit used to accurately measure the potential difference between the two ends of the channel under test. It can be implemented by using a differential amplifier circuit in conjunction with a high-precision analog-to-digital converter. By suppressing common-mode interference and amplifying the effective signal, the acquisition accuracy of weak voltage signals can be improved.

[0073] The calculation unit 133 calculates the resistance value of the target test channel based on voltage and current;

[0074] Specifically, the calculation unit 133 refers to the processor module that performs resistance value calculation. It can be implemented by an embedded microcontroller or a digital signal processor. By acquiring synchronous sampling data of current and voltage in real time, it applies Ohm's law to calculate the resistance value and eliminates the systematic error introduced by the resistance of the wire.

[0075] In this embodiment, the current source unit 131 maintains the stability of the output current through a closed-loop feedback mechanism. For example, in a dynamic testing scenario, when the load fluctuates due to changes in the contact state of the tested channel, the current sampling circuit feeds back the actual current value to the PID controller in real time, dynamically adjusting the output current to maintain the set value. The voltage acquisition unit 132 adopts a differential input method, connecting to both ends of the tested channel through a shielded cable, effectively eliminating the influence of wire resistance and contact resistance in the test circuit on voltage measurement. The calculation unit 133 performs digital filtering on the synchronously acquired current and voltage data, removes high-frequency noise, calculates the resistance value, and selects the corresponding calibration parameters for compensation according to the test channel type, ensuring the accuracy of static and dynamic resistance measurements.

[0076] This embodiment separates the current application and voltage measurement circuits using a four-wire Kelvin connection, and combines a high-precision reference source with differential signal processing technology to significantly reduce the influence of the inherent impedance of the test system on the measurement results. Furthermore, this scheme achieves stable measurement under dynamic operating conditions through closed-loop current control and synchronous sampling mechanisms. This application can accurately measure contact resistance values ​​in the milliohm to ten-ohm range, effectively distinguishing between normal conduction, critical poor contact, and open / short circuit states. In dynamic testing scenarios, by synchronously acquiring current and voltage data in real time, it accurately captures the transient characteristics of resistance changes, providing a reliable data foundation for evaluating contact resistance stability.

[0077] In one embodiment of this specification, the signal processing module 140 includes a noise reduction unit 141 and a trend analysis unit 142.

[0078] The noise reduction unit 141 is used to filter each resistor value and output the filtered target resistor values.

[0079] Specifically, the noise reduction unit 141 refers to a circuit or algorithm module used to eliminate noise interference during resistance measurement. This can be implemented using a Kalman filter algorithm, a moving average filter algorithm, or a threshold comparison method. For example, for a dynamic resistance test channel, the Kalman filter algorithm can dynamically adjust the noise covariance matrix according to the equipment rotation speed, thus adapting to noise characteristics under different operating conditions; for a static resistance test channel, the moving average filter algorithm suppresses high-frequency noise through a moving average operation with a window length of 10 sampling points; for a continuity test channel, the threshold comparison method directly determines the resistance state through a preset threshold, avoiding invalid data processing.

[0080] The trend analysis unit 142 is used to determine the fluctuation range, standard deviation and resistance change slope of the target resistance value, and to generate the change trend of the target resistance value based on the fluctuation range, standard deviation and resistance change slope.

[0081] Specifically, the signal processing module 140 first selects the corresponding noise reduction method based on the type of the target test channel. The resistance data from the dynamic resistance test channel is processed by a Kalman filter to output a smoothed resistance sequence; the data from the static resistance test channel is processed using a moving average filtering algorithm to eliminate random noise; the resistance value of the continuity test channel is directly compared with a preset threshold to output the on / off state. The noise-reduced target resistance value is input to the trend analysis unit 142, which calculates the fluctuation range of the maximum and minimum values ​​by traversing the resistance sequence, quantifies the data dispersion using standard deviation, and obtains the slope of change by fitting a resistance-time curve using the least squares method. These three parameters are comprehensively analyzed to form a resistance change trend evaluation result, used to determine the stability of the contact resistance.

[0082] In this embodiment, through adaptive noise reduction based on channel type and calculation of multi-dimensional trend parameters, a precise match between noise suppression and trend analysis is achieved. This application can effectively eliminate noise interference from different types of test channels and improve the signal-to-noise ratio of resistance measurement data. Simultaneously, based on comprehensive trend analysis of fluctuation range, standard deviation, and slope of change, abnormal fluctuation patterns of contact resistance can be accurately identified, providing a quantitative basis for early warning of equipment contact performance degradation. For example, in the dynamic testing scenario of a wind power pitch system, this technology can capture abnormal changes in resistance slope caused by contact wear, avoiding missed detections caused by noise masking in traditional methods.

[0083] In one embodiment of this specification, the upper-level control module 110 includes a parameter configuration unit 111 and an instruction generation unit 112.

[0084] The parameter configuration unit 111 is used to receive channel test parameters input by the user;

[0085] Specifically, the parameter configuration unit 111 refers to an interface module used to receive and parse user-input test parameters. It can be implemented using a graphical user interface or an API interface, acquiring configuration information such as test channel type, current setpoint, and sampling frequency through human-machine interaction devices or communication protocols. This unit converts discrete input parameters into a structured data format, providing standardized input for subsequent instruction generation.

[0086] The instruction generation unit 112 is used to generate channel selection test instructions based on channel test parameters.

[0087] Specifically, the instruction generation unit 112 is a logic module that generates executable control instructions based on parameter configuration. It can be implemented using a microcontroller or a programmable logic device. By parsing the structured data output by the parameter configuration unit 111, it generates binary control instructions containing the target channel number, test mode, and excitation current value according to a preset protocol format. This unit converts parameters into actions, ensuring that the test process is executed according to predetermined logic.

[0088] In this embodiment, for example, a user inputs test parameters to the parameter configuration unit 111 via a touchscreen or external computer, such as selecting a dynamic resistance test mode, setting a 100mA excitation current, and a 50Hz sampling frequency. The parameter configuration unit 111 converts the input text or selections into a machine-readable data structure, for example, encoding the dynamic resistance mode as binary 01 and quantizing the current value as a 12-bit digital value. After receiving the data structure, the instruction generation unit 112 calls a preset instruction template to fill in the parameters, generating a complete instruction frame containing the channel address, test mode code, and current setting value, and sends it to the multi-channel switching module 120 via the SPI bus. This process achieves seamless integration from manual input to device execution, avoiding the risk of parameter missetting in traditional manual operation.

[0089] In this embodiment, the solution uses a parameter configuration unit 111 to achieve digital input and formatted storage, and an instruction generation unit 112 to automatically construct control instructions based on the parameter data, eliminating errors from manual translation and improving the matching accuracy between parameter settings and instruction execution. For example, in dynamic resistance testing scenarios, other methods require setting three independent knobs for channel number, test mode, and sampling rate, while this solution uses a parameter configuration unit 111 to receive composite parameters at once, and an instruction generation unit 112 to automatically generate composite instructions, reducing operation steps and setting time. This application achieves automated processing of test parameter input and instruction generation, effectively solving the problems of low efficiency and error-proneness of manual settings. The parameter configuration unit 111 ensures parameter integrity through structured data input, and the instruction generation unit 112 automatically generates standardized instructions based on the parameters, improving the reliability and consistency of the testing process. In multi-channel testing scenarios for wind power equipment, this solution supports batch parameter import and instruction sequence generation, meeting the high-efficiency testing needs under complex operating conditions.

[0090] In one embodiment of this specification, the current source unit 131 employs closed-loop feedback control, including a PID regulator, a low-temperature drift reference voltage source, and a current sampling circuit.

[0091] A PID controller is used to dynamically adjust the output current;

[0092] Specifically, a PID controller is a closed-loop controller based on proportional, integral, and derivative components. It can be implemented using an analog circuit built with an operational amplifier or a digital processor. It dynamically adjusts the drive signal of the current source by calculating the linear combination of the output current error in real time.

[0093] The low-temperature drift reference voltage source provides a current setting reference;

[0094] Specifically, a low-temperature drift reference voltage source refers to a high-precision reference source with a temperature coefficient of less than 1ppm / ℃. It can be a bandgap reference circuit or a Zener diode structure to provide a long-term stable voltage reference for the current setting value.

[0095] The current sampling circuit monitors the output current in real time and feeds it back to the PID controller.

[0096] Specifically, the current sampling circuit refers to the detection loop that converts the output current into a voltage signal. It can be implemented using a precision shunt resistor in conjunction with a differential amplifier to acquire the current signal in real time and feed it back to the control loop.

[0097] In this embodiment, closed-loop feedback control acquires the actual value of the output current in real time through a current sampling circuit, compares it with the target value set by a low-temperature drift reference voltage source, and generates an error signal. The PID controller automatically adjusts the output power of the drive circuit based on the dynamic characteristics of the error signal to compensate for current deviations caused by changes in load impedance or fluctuations in ambient temperature. For example, when the measured resistance suddenly decreases, the current sampling circuit detects an upward trend in the output current, and the PID controller immediately reduces the drive voltage to maintain a constant current state. This control process is completed within microseconds, ensuring the stability of the test current under dynamic operating conditions.

[0098] This solution, by introducing a closed-loop feedback mechanism combined with a low-temperature drift reference source and high-speed PID control, effectively suppresses the interference of temperature changes on the reference source while rapidly responding to dynamic changes in load impedance. For example, in scenarios where equipment rotation causes instantaneous fluctuations in contact resistance, the closed-loop system can control the current fluctuation amplitude within ±0.1% of the set value, significantly better than the typical ±2% accuracy of the open-loop system. This application achieves high-precision and stable output of the test current, solving the measurement error problem caused by current fluctuations in dynamic resistance testing. The closed-loop feedback mechanism effectively compensates for the effects of line impedance changes and ambient temperature drift, ensuring the long-term stability of the current value under different test conditions. The coordinated operation of the current sampling circuit and the PID controller enables the system to quickly respond to load changes, providing a reliable excitation source for accurate measurement of dynamic resistance.

[0099] In one embodiment of this specification, the voltage acquisition unit 132 employs a differential amplifier circuit.

[0100] In this embodiment, the differential amplifier circuit refers to an amplifier circuit composed of two symmetrical input ports. Specifically, it can be implemented using a combination of instrumentation amplifiers or operational amplifiers, and is used to suppress common-mode interference signals and amplify differential-mode signals. Common-mode signals refer to in-phase interference signals that appear simultaneously at both input ports, while differential-mode signals refer to the effective voltage difference between the two input ports. The differential amplifier circuit filters out environmental electromagnetic interference through its common-mode rejection ratio (CMRR) parameter.

[0101] Specifically, during contact resistance testing, the test cable is susceptible to electromagnetic interference from the motor's operation, leading to common-mode noise superimposed on the voltage acquisition signal. The two input terminals of the differential amplifier circuit are connected to the positive and negative terminals of the channel under test, respectively, and common-mode interference is eliminated through subtraction. For example, when using the AD8421 instrumentation amplifier, its input stage has a built-in electromagnetic shielding structure, effectively isolating external magnetic field coupling. After pre-filtering, the input signal enters the differential amplifier, where common-mode interference is suppressed, and the effective signal is amplified and output to the analog-to-digital converter. In dynamic resistance testing scenarios, when changes in equipment speed cause fluctuations in the interference frequency, the wideband common-mode rejection characteristics of the differential amplifier circuit still maintain stable signal extraction capabilities.

[0102] Differential amplification technology, through a dual-path symmetrical input structure, eliminates interference signals as common-mode components while amplifying the effective signal as differential-mode components. This design significantly improves the signal-to-noise ratio of voltage measurements in the high electromagnetic interference environment of wind power generation equipment. This application solves the problem of voltage signals being susceptible to common-mode interference in dynamic resistance testing, leading to measurement inaccuracies. The differential amplification circuit effectively filters out electromagnetic noise introduced by the test cables, ensuring the accuracy and reliability of the voltage data required for resistance calculations, and is particularly suitable for operating environments with strong electromagnetic interference, such as pitch systems.

[0103] In one embodiment of this specification, the noise reduction unit 141 selects a noise reduction method according to the type of the target test channel, specifically including:

[0104] For the dynamic resistance test channel, a Kalman filter algorithm is used. The noise covariance matrix is ​​dynamically adjusted according to the equipment rotation speed, and the filter window length is adaptively set according to the sampling frequency; for example, the filter window length is 5-20 sampling periods.

[0105] Specifically, the Kalman filter algorithm is a recursive filtering method based on a state-space model. It can be implemented by adjusting the noise covariance matrix in real time, and by dynamically tracking the changes in the equipment rotation speed to adjust the filtering parameters, thereby suppressing random noise in dynamic resistance testing.

[0106] The dynamic resistance test channel generates time-varying noise during equipment rotation. The noise covariance matrix is ​​updated in real time using a Kalman filter algorithm. For example, when the equipment speed increases, the process noise covariance is increased to adapt to rapid changes. At the same time, the filter window length of 5 to 20 sampling periods is selected according to the dynamic characteristics to balance the response speed and smoothing effect.

[0107] For the static resistance test channel, a moving average filtering algorithm is used, with the filtering window length matched to the sampling frequency; for example, the window length is 10 sampling points and the step size is 1.

[0108] Specifically, the moving average filtering algorithm refers to the weighted averaging of continuous sampling points, which can be implemented by using a fixed window length and step size to eliminate high-frequency interference in static resistance testing through smoothing.

[0109] The noise in the static resistance test channel is mainly steady-state interference. A moving average filter with a window length of 10 sampling points is used. The calculation is performed by moving one sampling point at a time to gradually eliminate random fluctuations.

[0110] For continuity test channels, the threshold comparison method is used to directly determine the resistance status;

[0111] Specifically, the threshold comparison method refers to setting upper and lower threshold values ​​for the resistance value. This can be achieved by using a preset continuity judgment standard, which directly compares the measured value with the threshold to quickly determine the continuity status. The continuity test channel needs to quickly determine the on / off status. This is done by directly comparing the measured resistance value with a set threshold range. For example, when the resistance value exceeds 1 kiloohms, it is determined to be an open circuit, and when it is below 10 milliohms, it is determined to be a short circuit, achieving a millisecond-level response.

[0112] In this embodiment, the proposed solution designs differentiated noise reduction strategies based on the noise characteristics of different test channels, solving the problems of noise parameter mismatch in dynamic testing, insufficient smoothness in static testing, and low efficiency in continuity testing. This application achieves real-time noise tracking and suppression in dynamic resistance testing, improving the accuracy of capturing transient changes; optimizes the smoothing effect of static resistance test data, avoiding measurement deviations caused by high-frequency interference; simplifies the judgment logic of continuity testing, and shortens the response time. Different types of test channels employ appropriate noise reduction methods, improving overall processing efficiency while ensuring measurement accuracy.

[0113] In one embodiment of this specification, the trend analysis unit 142 fits the resistance-time curve using the least squares method to calculate the fluctuation range, standard deviation, and slope of the target resistance value, which serve as the evaluation result of the trend.

[0114] In this embodiment, the optimal curve is fitted by minimizing the sum of the squared differences between the predicted and actual values. This can be achieved using a linear regression algorithm to eliminate random noise interference and extract the overall trend of resistance changes. The fluctuation range refers to the difference between the maximum and minimum resistance values ​​in the time series. This can be achieved by traversing the filtered resistance data series and recording the extreme values, characterizing the amplitude of dynamic resistance changes. The standard deviation is an indicator of the dispersion of the resistance value relative to the mean. This can be achieved by calculating the square root of the average of the squared differences between each data point and the mean, quantifying the stability of resistance fluctuations. The slope of change refers to the linear trend slope of the resistance-time curve. This can be calculated using the derivative of the fitted line, determining the rate and direction of resistance change over time.

[0115] Specifically, the raw data collected by the resistance measurement module 130 is processed to form a time-series resistance value. The trend analysis unit 142 constructs a two-dimensional dataset with time as the independent variable and resistance value as the dependent variable. The slope and intercept of the best-fit line are calculated using the least squares method to generate a trend line of resistance changing over time. Simultaneously, the entire dataset is traversed to identify the maximum and minimum resistance values, and the difference in fluctuation range is calculated. The standard deviation is calculated based on the fitted residual data to reflect the dispersion of the resistance value. Finally, the fluctuation range, standard deviation, and slope are output as comprehensive evaluation indicators to form a quantitative assessment of the contact resistance performance.

[0116] In some specific implementations, the fitting of the resistance-time curve can be performed in segments. For example, when the equipment rotation speed changes, the time interval can be automatically divided and the trend parameters of each segment can be calculated separately. The standard deviation can be calculated using a sliding window method, for example, updating the dispersion index every 10 sampling points. The slope calculation can be combined with the equipment operating status, for example, distinguishing the slope changes during the forward and reverse rotation phases within the rotation cycle.

[0117] This solution extracts three key indicators—fluctuation range, dispersion, and rate of change—through mathematical modeling, enabling the differentiation between transient disturbances and actual performance degradation, thus addressing the problem of insufficient trend feature extraction in dynamic resistance assessment. This application achieves multi-dimensional quantitative analysis of the dynamic characteristics of contact resistance, accurately identifying gradual faults and predicting potential failure risks, providing data support for equipment maintenance.

[0118] In some other embodiments of this specification, the multi-channel intelligent contact resistance testing device 10 integrates a self-testing and calibration module, specifically including:

[0119] Automatic calibration function: It automatically calibrates every 24 hours through built-in 0.1Ω, 1Ω, and 10Ω precision low-temperature drift resistors (accuracy ±0.1%), covering the range from 1mΩ to 10Ω, with a calibration error ≤ ±0.05%.

[0120] Channel self-test logic: When the relay array switches, the channel conduction status is monitored in real time. If an open circuit / short circuit is detected, the faulty channel is marked through the host computer software and an audible and visual alarm is triggered.

[0121] Accuracy verification process: Before testing, the "reference resistance test" is automatically run to compare the measured value with the nominal value. If the deviation is >0.2%, a recalibration prompt will be given to ensure the reliability of the test.

[0122] In some other embodiments of this specification, the multi-channel intelligent contact resistance testing device 10 integrates a power supply module, which uses a lithium battery pack, specifically configured as follows:

[0123] Battery pack structure: 3 18650 lithium batteries are connected in series and then 2 groups are connected in parallel, with a total voltage of 12V and a capacity of 5000mAh. It is equipped with a balance protection board to achieve overcharge / over-discharge protection.

[0124] Battery life performance: Under 25℃ conditions, continuous testing of 96 channels at a 100Hz sampling rate yielded a measured battery life of ≥8 hours; supports charging via an external 12V adapter, with a charging time of ≤4 hours.

[0125] Low power management: When the battery level is below 10%, the host computer interface displays a red warning and automatically switches to low power mode, limiting the high current test function.

[0126] In some other embodiments of this specification, the signal processing module 140 further includes:

[0127] The extended data management unit specifically includes:

[0128] Database design: An embedded SQLite database is used, and the stored fields include product model, batch number, test time, channel number, resistance value, fluctuation range and alarm status.

[0129] Excel export function: Supports one-click export of test records as .xlsx files, including raw data, resistance-time trend charts, and pass rate statistical reports.

[0130] Multi-dimensional query: Users can filter records by fields such as "product batch", "test date" or "operator", and fuzzy search is supported (e.g., enter "2023-07" to query all test data for the current month).

[0131] In some other embodiments of this specification, the signal processing module 140 also integrates alarm protection logic, specifically including:

[0132] Threshold dynamic setting: The dynamic resistance fluctuation range (ΔR) threshold can be customized (default ±5%), and the short-circuit threshold for continuity test is set to <10mΩ.

[0133] Alarm triggering mechanism: When ΔR exceeds the limit, the yellow LED on the panel flashes and the buzzer sounds; the host computer pops up a window to indicate the fault channel number, the current resistance value, and suggested handling measures.

[0134] Fault isolation handling: The matrix switching module automatically isolates faulty channels, skips subsequent tests, and records fault logs to avoid affecting the overall test progress.

[0135] In some other embodiments of this specification, the multi-channel switching module 120 supports matrix expansion, specifically including:

[0136] Basic array: A 32-channel relay matrix (4×8) serves as the basic unit, supporting four-wire channel switching.

[0137] Cascading Expansion: Three basic units can be cascaded via the SPI bus to form a 96-channel full matrix (12×8), with a switching time of ≤10ms.

[0138] Redundancy design: Each relay contact is connected to two normally open contacts in parallel. In the event of a single-path failure, it automatically switches to the backup contact to ensure test continuity.

[0139] In some other embodiments of this specification, the multi-channel switching module further includes: a resistance value prediction unit, used to quickly sample the initial resistance value of each channel before channel switching; a channel allocation unit, used to assign priority to channels according to the initial resistance value, giving higher priority to channels whose resistance value is close to a set threshold or changes drastically, and increasing the test frequency and data acquisition density in subsequent tests; and a resource allocation unit, used to dynamically allocate more precise test resources to high-priority channels, including more precise current sources and voltage acquisition units, to improve the test accuracy and reliability of critical channels.

[0140] In some other embodiments of this specification, the multi-channel switching module further includes: a stability monitoring unit for real-time monitoring of the connection stability of each channel during testing; and a dynamic adjustment unit for dynamically adjusting the testing strategy based on the connection stability, including:

[0141] When the connection stability is lower than the set threshold, the test frequency of the channel is automatically reduced to reduce interference with unstable connections;

[0142] Meanwhile, the frequency of monitoring the connection status of this channel is increased to promptly detect and address connection problems; the data compensation unit provides real-time compensation for data anomalies caused by unstable connections, ensuring the continuity and reliability of test data.

[0143] In some other embodiments of this specification, the apparatus further includes a collaborative enhancement and optimization module, specifically comprising:

[0144] The channel status monitoring unit monitors the operating status of each channel in real time (such as current, voltage, temperature, etc.) and generates status reports.

[0145] The status aggregation unit aggregates the status reports from each channel to generate a global status graph, displaying the overall operating status of all channels;

[0146] The collaborative enhancement unit adopts a novel "collaborative enhancement" strategy based on the global state map, which optimizes the measurement accuracy of other channels by adjusting the measurement parameters of some channels.

[0147] Specific methods include, but are not limited to: increasing the excitation current intensity of certain channels to improve their measurement accuracy, while reducing the excitation current intensity of adjacent channels to reduce interference.

[0148] The following is combined with Figures 3 to 6 The multi-channel intelligent contact resistance testing device 10 is introduced below.

[0149] Figure 3 The main interface of the tester's host computer software after startup is displayed, containing the following key elements: Equipment Model Selection Area: Provides a drop-down menu or list box for selecting the model of the wind turbine equipment under test (e.g., pitch system model). Test Mode Switching Button: Contains three independent tabs: "Continuity Test," "Static Resistance Test," and "Dynamic Resistance Test," which users can switch between. Real-time Status Bar: Displays the current tester connection status (e.g., "Connected," "Not Connected"), battery level (percentage), and self-test status (e.g., "Self-test Passed"). Start / Stop Buttons: "Start Test" and "Stop Test" buttons are used to control the test process.

[0150] Figure 4 In the settings, the channel parameters are as follows: The input box displays "Current number of channels: 96," which can be manually modified (e.g., reduced to 32 channels). Current setting: The slider or numeric input box sets the test current (range 0–200mA, default 100mA). Dynamic test parameters: Sampling frequency (Hz) defaults to 100Hz, adjustable to 50Hz or 200Hz. Fluctuation threshold (%): default ±5%, used for dynamic resistance alarms. Alarm settings: Checkboxes enable / disable audible and visual alarms; threshold exceeding limits are indicated by color (early warnings and alarms can use different colors).

[0151] Figure 5 In the real-time testing process, the main interface is divided into three areas:

[0152] Real-time Data Area: Displays the current resistance values ​​(in mΩ) of all 96 channels in tabular format, with abnormal values ​​(such as open circuits or short circuits) marked in a set color. Trend Graph Area: Dynamically plots resistance-time curves (horizontal axis: time, vertical axis: resistance value), supporting zooming and panning. Alarm Display Area: Displays scrolling alarm information (e.g., "Channel #45 Fluctuation Exceeds Limit: ΔR=6.2%)", simultaneously triggering panel LED flashing and a buzzer.

[0153] Figure 6 The historical data query interface includes the following functions:

[0154] Filter criteria: Product batch number (text box); Test date range (calendar selector); Operator name (drop-down menu); Query results list: A table displaying summary information of matching records (such as batch number, test time, pass rate).

[0155] Operation buttons: "View Details": Jumps to the complete data (including line chart) of a single record. "Export Excel": Generates an .xlsx file containing raw data, trend charts, and statistical reports. "Print Report": Calls the printer to output a PDF test report.

[0156] Based on the same general inventive concept, this invention also protects a multi-channel intelligent contact resistance testing method, such as... Figure 7 As shown, Figure 7 This is a schematic flowchart of the multi-channel intelligent contact resistance testing method provided in an embodiment of the present invention. The multi-channel intelligent contact resistance testing method provided by the present invention will be described below. The multi-channel intelligent contact resistance testing method described below can be referred to in correspondence with the multi-channel intelligent contact resistance testing device described above.

[0157] Multi-channel intelligent contact resistance testing methods include:

[0158] Step 710: Receive the channel test parameters of the contact resistance and generate a channel selection test command based on the channel test parameters;

[0159] Step 720: Based on the channel selection test command, switch to the target test channel of the corresponding type;

[0160] Step 730: Apply the corresponding type of current according to the type of the target test channel, and collect the voltage of the target test channel. Obtain the resistance value based on the voltage and current.

[0161] Step 740: Perform noise reduction processing on the resistance value to obtain the target resistance value, and evaluate the changing trend of the target resistance value.

[0162] Figure 8 This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention.

[0163] like Figure 8 As shown, the electronic device may include a processor 810, a communications interface 820, a memory 830, and a communication bus 840. The processor 810, communications interface 820, and memory 830 communicate with each other via the communication bus 840. The processor 810 can call logic instructions from the memory 830 to execute a multi-channel intelligent contact resistance testing method.

[0164] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0165] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the multi-channel intelligent contact resistance testing method provided by the above methods.

[0166] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the multi-channel intelligent contact resistance testing method provided by the methods described above.

[0167] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0168] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, 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 can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-channel intelligent contact resistance testing device, characterized in that, The intelligent contact resistance testing device integrates multiple different types of resistance testing channels, including continuity testing channels, static resistance testing channels, and dynamic resistance testing channels. The device includes: The host control module is used to receive the channel test parameters of the contact resistance and generate a channel selection test command based on the channel test parameters. The multi-channel switching module switches to the corresponding target test channel based on the channel selection test command. The resistance measurement module applies a current of the corresponding type according to the type of the target test channel, and acquires the voltage of the target test channel, and obtains the resistance value based on the voltage and the current; The signal processing module performs noise reduction processing on the resistance value to obtain the target resistance value and evaluates the changing trend of the target resistance value. The signal processing module includes: The noise reduction unit employs a Kalman filter algorithm for the dynamic resistance test channel, with the noise covariance matrix dynamically adjusted according to the equipment rotation speed and the filter window length adaptively set according to the sampling frequency; for the static resistance test channel, a moving average filter algorithm is used, with the filter window length matched to the sampling frequency; and for the continuity test channel, a threshold comparison method is used to directly determine the resistance status. The trend analysis unit fits the resistance-time curve using the least squares method to calculate the fluctuation range, standard deviation, and slope of the target resistance value, which serve as the evaluation result of the trend.

2. The multi-channel intelligent contact resistance testing device according to claim 1, characterized in that, The multi-channel switching module includes: The relay array unit is a multi-channel matrix structure that supports at least 32 four-wire channel switching and is used to switch to the corresponding target test channel according to the channel selection test command. The channel status feedback unit is used to provide real-time feedback on the conduction status of the target test channel to the upper control module; wherein, the conduction status includes conduction, short circuit and open circuit.

3. The multi-channel intelligent contact resistance testing device according to claim 1, characterized in that, The resistance measurement module includes: A current source unit is used to apply current to the target test channel; A voltage acquisition unit is used to acquire the voltage across the target test channel. The calculation unit calculates the resistance value of the target test channel based on the voltage and the current.

4. The multi-channel intelligent contact resistance testing device according to claim 1, characterized in that, The host control module includes: A parameter configuration unit is used to receive the channel test parameters input by the user; The instruction generation unit is used to generate the channel selection test instruction based on the channel test parameters.

5. The multi-channel intelligent contact resistance testing device according to claim 3, characterized in that, The current source unit employs closed-loop feedback control, including: A PID controller is used to dynamically adjust the output current. Low-temperature drift reference voltage source provides a current setting reference; The current sampling circuit monitors the output current in real time and feeds it back to the PID controller.

6. The multi-channel intelligent contact resistance testing device according to claim 3, characterized in that, The voltage acquisition unit uses a differential amplifier circuit.

7. A multi-channel intelligent testing method for contact resistance, characterized in that, The method is applied to the multi-channel intelligent contact resistance testing device according to any one of claims 1 to 6, and the method includes: Receive channel test parameters for contact resistance and generate channel selection test instructions based on the channel test parameters; Based on the channel selection test command, switch to the target test channel of the corresponding type; According to the type of the target test channel, apply a current of the corresponding type and collect the voltage of the target test channel, and obtain the resistance value based on the voltage and the current; The resistance value is subjected to noise reduction processing to obtain the target resistance value, and the changing trend of the target resistance value is evaluated. The process includes noise reduction of the resistance value to obtain the target resistance value, and evaluation of the changing trend of the target resistance value, including: For the dynamic resistance test channel, a Kalman filter algorithm is used, with the noise covariance matrix dynamically adjusted according to the equipment rotation speed and the filter window length adaptively set according to the sampling frequency; for the static resistance test channel, a moving average filter algorithm is used, with the filter window length matched to the sampling frequency; for the continuity test channel, a threshold comparison method is used to directly determine the resistance status. By fitting the resistance-time curve using the least squares method, the fluctuation range, standard deviation, and slope of the target resistance value are calculated as evaluation results of the change trend.

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