A kind of disconnecting switch opening and closing position detection method

Abstract

The application discloses a kind of methods suitable for isolating switch opening and closing position detection, belong to isolating switch detection technical field.This method includes: obtaining the first contact resistance sequence of each detection point when isolating switch is in opening position and the second contact resistance sequence when closing position;According to the real-time temperature value of each detection point, heat drift compensation is carried out on two sequences, and first compensation sequence and second compensation sequence are obtained accordingly;According to the two compensation sequences, the opening and closing state characteristic interval of each detection point is constructed;Real-time contact resistance value and real-time temperature value are collected and heat drift compensation is carried out, to obtain real-time compensation resistance value;According to the spatial position relationship between real-time compensation resistance value and opening and closing state characteristic interval, the current opening and closing position of isolating switch is determined.The method can eliminate the interference of temperature change on contact resistance measurement, and realize reliable opening and closing state judgment according to statistical characteristic interval.

Description

Technical Field

[0001] This invention relates to the field of disconnector switch testing technology, specifically a method for detecting the open / closed position of a disconnector switch. Background Technology

[0002] Detecting the open / close position of disconnecting switches is crucial for the safe operation of power systems. Current technologies, which determine the open / close status by measuring contact resistance, typically rely on directly collecting the contact resistance value between the contacts and making decisions based on a single threshold or fixed range. Contact resistance is significantly affected by temperature; the resistivity of the contact material increases with temperature, leading to a noticeable drift in contact resistance values ​​measured under different ambient temperatures or load temperature rises, even under the same contact condition. When the temperature rise is significant, the contact resistance at the closed position may overlap with the resistance value at the open position at lower temperatures, causing misjudgment by the detection system. To reduce the impact of temperature, some solutions use temperature sensors to monitor the ambient temperature and set a coarse temperature compensation coefficient. However, these compensation methods are often based on overall empirical values ​​and fail to fully reflect the resistance change characteristics of each contact detection point at a specific temperature, resulting in insufficient compensation accuracy and a risk of misjudgment under conditions of large temperature fluctuations. Furthermore, existing discrimination methods often directly compare the compensated resistance value with a single threshold, without fully considering the statistical distribution characteristics of contact resistance values ​​under the same conditions. Factors such as contact surface condition and minor vibrations cause the contact resistance value in the same state to fluctuate within a normal range. A single threshold cannot describe this distribution boundary, resulting in poor robustness in judging the resistance value near the boundary, easily causing state jumps or failure to determine the state. Based on these problems, it is necessary to solve how to accurately compensate for contact resistance drift under temperature changes and to construct a reliable state determination interval using the statistical distribution characteristics of the resistance values ​​at each detection point, thereby improving the accuracy and stability of opening and closing detection. Summary of the Invention

[0003] This invention provides a method for detecting the open / close position of a disconnecting switch, aiming to achieve reliable detection of the open / close position of the disconnecting switch, eliminate the influence of temperature changes on the measured contact resistance value, and improve the fault tolerance and anti-interference capability of the discrimination method by constructing an open / close state interval based on statistical characteristics.

[0004] To achieve the above objectives, the present invention provides the following technical solution: The present invention proposes a method for detecting the open / closed position of a disconnecting switch. The method includes: The invention obtains a first contact resistance sequence corresponding to each detection point when the disconnecting switch is in the open position, and a second contact resistance sequence corresponding to each detection point when the disconnecting switch is in the closed position. As a technical solution of the invention, each contact of the disconnecting switch is independently assigned a detection point; when the disconnecting switch is in the open position, the contact resistance values ​​of each detection point are continuously collected at multiple sampling times to form a first contact resistance sequence corresponding to each detection point; when the disconnecting switch is in the closed position, the contact resistance values ​​of each detection point are continuously collected at multiple sampling times to form a second contact resistance sequence corresponding to each detection point; the number of sampling times corresponding to each detection point is the same.

[0005] Based on the real-time temperature values ​​at each detection point, thermal drift compensation is performed on the first contact resistance sequence and the second contact resistance sequence to obtain a first compensation sequence and a second compensation sequence. Preferably, the real-time temperature values ​​at each detection point are collected simultaneously at each sampling time; based on the real-time temperature value of each detection point at each sampling time, a preset resistance temperature coefficient corresponding to that temperature value is obtained; the contact resistance value at each sampling time in the first contact resistance sequence of each detection point is divided by the preset resistance temperature coefficient at the corresponding sampling time to obtain the first compensation sequence of that detection point; the contact resistance value at each sampling time in the second contact resistance sequence of each detection point is divided by the preset resistance temperature coefficient at the corresponding sampling time to obtain the second compensation sequence of that detection point. The preset resistance temperature coefficient is obtained by performing contact resistance calibration experiments and fitting at multiple temperature calibration points for each detection point beforehand.

[0006] Based on the first compensation sequence and the second compensation sequence, the opening and closing state characteristic intervals for each detection point are constructed. Specifically, the mean value of all compensation resistance values ​​in the first compensation sequence of each detection point is calculated as the opening characteristic value of that detection point; the mean value of all compensation resistance values ​​in the second compensation sequence of each detection point is calculated as the closing characteristic value of that detection point; the standard deviation of the first compensation sequence of each detection point is added to and subtracted from the opening characteristic value of each detection point to obtain the opening state sub-interval of that detection point; the standard deviation of the second compensation sequence of each detection point is added to and subtracted from the closing characteristic value of each detection point to obtain the closing state sub-interval of that detection point; the opening state sub-intervals and closing state sub-intervals of all detection points are merged to form the overall opening state characteristic interval and the overall closing state characteristic interval.

[0007] The system collects the real-time contact resistance and temperature values ​​of each detection point of the disconnect switch at the current moment. In a preferred embodiment, at the current detection moment, the system simultaneously reads the real-time contact resistance value output by the contact resistance sensor corresponding to each detection point; at the current detection moment, it simultaneously reads the real-time temperature value output by the temperature sensor corresponding to each detection point; and stores the real-time contact resistance and temperature values ​​of each detection point in pairs according to the detection point number.

[0008] Thermal drift compensation is performed on the real-time contact resistance value based on the real-time temperature value to obtain the real-time compensation resistance value. For each detection point, the preset resistance temperature coefficient corresponding to the detection point is queried based on the real-time temperature value of the detection point; the real-time contact resistance value of each detection point is divided by the preset resistance temperature coefficient of the corresponding detection point to obtain the real-time compensation resistance value of each detection point; the real-time compensation resistance values ​​of all detection points are combined in the order of detection point numbers to form a real-time compensation vector.

[0009] Based on the spatial relationship between the real-time compensation resistance value and the characteristic interval of the opening and closing states, the current opening and closing position of the disconnecting switch is determined. Specifically, it is determined whether the real-time compensation resistance value of each detection point falls within the opening state sub-interval corresponding to that detection point, and the number of detection points falling within the opening state sub-interval is counted and recorded as the first quantity; it is also determined whether the real-time compensation resistance value of each detection point falls within the closing state sub-interval corresponding to that detection point, and the number of detection points falling within the closing state sub-interval is counted and recorded as the second quantity; when the first quantity is greater than the second quantity, the disconnecting switch is determined to be in the opening position; when the second quantity is greater than the first quantity, the disconnecting switch is determined to be in the closing position.

[0010] Further, the specific method for determining whether the real-time compensation resistance value of each detection point falls within the corresponding open state sub-interval is as follows: compare the real-time compensation resistance value of each detection point with the lower limit and upper limit of the open state sub-interval for that detection point; if the real-time compensation resistance value is greater than or equal to the lower limit and less than or equal to the upper limit, then the detection point is determined to fall within the open state sub-interval; count the number of detection points falling within the open state sub-interval among all detection points to obtain the first quantity. Similarly, the specific method for determining whether the real-time compensation resistance value of each detection point falls within the corresponding closed state sub-interval is as follows: compare the real-time compensation resistance value of each detection point with the lower limit and upper limit of the closed state sub-interval for that detection point; if the real-time compensation resistance value is greater than or equal to the lower limit and less than or equal to the upper limit, then the detection point is determined to fall within the closed state sub-interval; count the number of detection points falling within the closed state sub-interval among all detection points to obtain the second quantity.

[0011] The above scheme eliminates measurement drift caused by temperature changes by collecting contact resistance sequences of historical opening and closing positions and introducing temperature compensation, making the constructed opening and closing state characteristic interval more representative and stable. By adopting sub-intervals based on point-by-point matching of detection points and a voting mechanism to determine the position, it can reduce the interference of individual detection point anomalies on the overall judgment and improve the accuracy and reliability of disconnector switch opening and closing position detection in complex environments.

[0012] The technical effects and advantages provided by the present invention in the above technical solution are as follows: By acquiring the contact resistance sequences at each detection point in both the open and closed positions, and using the real-time temperature values ​​synchronously collected at each sampling moment, thermal drift compensation is performed point-by-point and time-by-time using a preset resistance temperature coefficient. The contact resistance values ​​are then converted to reference temperature conditions before being used for state feature construction. The preset resistance temperature coefficient is obtained through contact resistance calibration experiments at multiple temperature calibration points for each detection point, fully reflecting the independent thermal resistance characteristics of each contact, rather than using a globally uniform compensation coefficient. The compensation process divides each sampling point in the first and second contact resistance sequences by the preset coefficient at the corresponding temperature to obtain the first and second compensation sequences. During real-time detection, compensation is also performed based on the current temperature and the corresponding coefficient. The resulting resistance values ​​exhibit good consistency over a wide temperature range, effectively eliminating resistance drift caused by changes in ambient temperature or contact self-heating, keeping the resistance values ​​corresponding to the open and closed states within a stable range, and fundamentally reducing misjudgments caused by temperature overlap. Based on the compensated sequence, the opening and closing characteristic values ​​of each detection point are calculated, which are the mean of the corresponding compensated sequence. Then, combined with the standard deviation of each sequence, the opening and closing sub-intervals for each detection point are constructed by adding and subtracting the standard deviation from the mean. These sub-intervals of all detection points are then merged to form the overall opening and closing characteristic intervals. This interval construction method utilizes the natural discreteness of resistance values ​​under the same state, using statistical boundaries to describe the normal fluctuation range, eliminating reliance on subjectively set fixed thresholds. When determining the position of the real-time compensated resistance value, it is checked whether the real-time compensated resistance value of each detection point falls into the corresponding opening or closing sub-interval. The number of detection points falling into each interval is counted, and the current opening / closing state is determined based on a majority vote principle. This method integrates information from multiple detection points. Even if individual detection points fall into the wrong interval due to local anomalies, it will not change the final judgment result, significantly enhancing the fault tolerance of the detection method for local fluctuations in contact resistance and avoiding erroneous judgments caused by signal distortion at a single detection point. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0014] Figure 1 This is a flowchart of the method for detecting the open / closed position of a disconnector switch; Figure 2This is a flowchart of synchronous acquisition and thermal drift compensation of contact resistance at multiple detection points of disconnecting switches; Figure 3 This is a graph showing the relationship between the real-time contact resistance and compensation resistance of the disconnector switch detection point and temperature. Figure 4 It is the contact resistance temperature calibration and fitting curve. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] See Figure 1 This invention provides a method for detecting the open / closed position of a disconnecting switch. The method includes: acquiring a first contact resistance sequence corresponding to each detection point when the disconnecting switch is in the open position, and a second contact resistance sequence corresponding to each detection point when it is in the closed position; performing thermal drift compensation on the first contact resistance sequence and the second contact resistance sequence based on the real-time temperature value at each detection point to obtain a first compensation sequence and a second compensation sequence; constructing a characteristic interval of the open / closed state for each detection point based on the first compensation sequence and the second compensation sequence; collecting the real-time contact resistance value and the real-time temperature value at each detection point of the disconnecting switch at the current moment; performing thermal drift compensation on the real-time contact resistance value based on the real-time temperature value to obtain a real-time compensation resistance value; and determining the current open / closed position of the disconnecting switch based on the spatial relationship between the real-time compensation resistance value and the characteristic interval of the open / closed state.

[0017] In practice, each contact of the disconnecting switch is equipped with an independent detection point. Each detection point is equipped with a contact resistance sensor and a temperature sensor. The contact resistance sensor is used to measure the resistance value of the contact circuit, and the temperature sensor is used to measure the ambient temperature near the contact.

[0018] When the disconnector is in the open position, synchronous data acquisition is performed on all detection points. The contact resistance value of each detection point is continuously acquired at multiple sampling times. The contact resistance values ​​at all sampling times corresponding to each detection point are arranged according to the acquisition sequence to form the first contact resistance sequence for that detection point. During the acquisition process, the total number of sampling times is set to N, where N is a positive integer greater than 1. For any detection point, its first contact resistance sequence can be expressed as: in, Indicates the detection point number. The value range is from 1 to M, where M is the total number of detection points; Indicates the sampling time number. The value range is from 1 to N; Indicates the number is The detection point is in the open position. The contact resistance value collected at each sampling time.

[0019] When the disconnector is in the closed position, synchronous data acquisition is performed on all detection points. The contact resistance values ​​of each detection point are continuously acquired at N sampling times, forming a second contact resistance sequence for each detection point. For any detection point, the second contact resistance sequence can be expressed as: in, Indicates the number is The detection point is in the closed position. The contact resistance value is collected at each sampling time. The number of sampling times for all detection points in both the open and closed positions is N, ensuring that the sequence length is the same.

[0020] At each sampling moment, the real-time temperature value at each detection point is simultaneously collected. For the numbered... The detection point, at the first The temperature value output by the temperature sensor is recorded synchronously at each sampling time, and denoted as . Therefore, corresponding to each of the first contact resistance sequence Each of them has a synchronously acquired temperature value. ; corresponding to each of the second contact resistance sequence Similarly, there is a synchronously acquired temperature value. .

[0021] Based on the real-time temperature value of each detection point at each sampling time, the preset temperature coefficient of resistance corresponding to that detection point at that temperature value is obtained. The preset temperature coefficient of resistance is defined as a normalization correction factor for the contact resistance value at different temperatures relative to a reference temperature. It is obtained by performing contact resistance calibration experiments on each detection point at multiple temperature calibration points and fitting the results. The fitting results form a mapping relationship between temperature and the preset temperature coefficient of resistance. In specific implementations, this mapping relationship is stored in the detection system in the form of a lookup table or a piecewise function. For example, for the numbered... The detection point is at temperature The preset temperature coefficient of resistance is denoted as . . It is a dimensionless numerical value, with a range greater than 0, and a value of 1 at the reference temperature.

[0022] Thermal drift compensation is performed on the first and second contact resistance sequences based on a preset temperature coefficient of resistance. The contact resistance value at each sampling time in the first contact resistance sequence for each detection point is divided by the preset temperature coefficient of resistance at the corresponding sampling time to obtain the first compensation sequence for that detection point. The elements in the first compensation sequence are represented as follows: in, Indicates the number is The detection point corresponds to the tripping position at the 1st The compensation resistor value at each sampling time.

[0023] Dividing the contact resistance value at each sampling time in the second contact resistance sequence of each detection point by the preset resistance temperature coefficient at the corresponding sampling time yields the second compensation sequence for that detection point. The elements in the second compensation sequence are represented as follows: in, Indicates the number is The detection point corresponds to the closing position at the 1st The compensation resistor value at each sampling time.

[0024] Through the above process, the first compensation sequence for each detection point is composed of all according to The second compensation sequence is composed of all the permutations from 1 to N. according to Arranged from 1 to N, it completes the thermal drift compensation for the contact resistance sequence.

[0025] In practice, for each detection point, a first compensation sequence is obtained. The first compensation sequence consists of N compensation resistor values. For the detection point numbered m, the compensation resistor value at the nth sampling time is denoted as... Where m is the detection point number, ranging from 1 to M, M is the total number of detection points, and n is the sampling time number, ranging from 1 to N, where N is the total number of sampling times. The tripping characteristic value of the detection point with number m is calculated. The tripping characteristic value is the arithmetic mean of all compensation resistor values ​​in the first compensation sequence. The formula for calculating the tripping characteristic value is: in, This represents the tripping characteristic value of the detection point numbered m, with the unit being the same as the resistance value unit; Indicates the total number of sampling times; This represents the compensation resistance value at the nth sampling moment corresponding to the tripping position of the detection point numbered m.

[0026] For each detection point, a second compensation sequence is obtained. The second compensation sequence consists of N compensation resistor values. In the second compensation sequence of the detection point numbered m, the compensation resistor value at the nth sampling time is denoted as... Calculate the closing characteristic value of the detection point numbered m. The closing characteristic value is the arithmetic mean of all compensation resistor values ​​in the second compensation sequence, denoted as m. The calculation method for the closing characteristic value is the same as that for the opening characteristic value, which is to sum all elements in the second compensation sequence and then divide by N.

[0027] In practice, the standard deviation of the first compensation sequence for the detection point numbered m is calculated and denoted as... The standard deviation of the first compensation sequence is obtained using the sample standard deviation calculation method with Bessel correction, that is, by first calculating the sum of the compensation resistor values ​​and the tripping characteristic values ​​in the first compensation sequence. The sum of squared deviations is obtained by dividing the sum of squared deviations by N and subtracting 1 to get the sample variance. The square root of the sample variance is then used to obtain the sample variance. Calculate the standard deviation of the second compensated sequence for the detection point numbered m, denoted as . The standard deviation of the second compensated sequence was obtained in the same way.

[0028] After calculating the eigenvalues ​​and standard deviations, a circuit breaker state sub-interval for detection point m is constructed. The circuit breaker eigenvalues ​​of detection point m are then... Add the standard deviation of the first compensated sequence at that detection point The upper limit value of the sub-interval of the tripping state is obtained. The tripping characteristic value of the detection point numbered m Subtract the standard deviation of the first compensated sequence at that detection point The lower limit value of the circuit breaker state sub-interval is obtained. The tripping state sub-interval consists of a lower limit value and an upper limit value, denoted as interval []. , ].

[0029] Construct a sub-interval for the closing status of detection point m. Assign the closing characteristic value of detection point m... Add the standard deviation of the second compensated sequence at that detection point The upper limit value of the sub-interval of the closed state is obtained. The closing characteristic value of the detection point numbered m Subtract the standard deviation of the second compensated sequence at that detection point The lower limit value of the closed state sub-interval is obtained. The closing state sub-interval consists of a lower limit value and an upper limit value, denoted as interval []. , ].

[0030] In practice, after constructing the aforementioned intervals for all detection points, the open state sub-intervals of all detection points are merged to form the overall open state characteristic interval. The overall open state characteristic interval is a set containing the open state sub-intervals corresponding to each detection point numbered 1 to M. The closed state sub-intervals of all detection points are then merged to form the overall closed state characteristic interval. The overall closed state characteristic interval contains the closed state sub-intervals corresponding to each detection point numbered 1 to M.

[0031] In specific implementation, please refer to Figure 2 At the current detection moment, synchronous data acquisition is performed on all detection points of the disconnector switch. Each detection point is pre-installed with a contact resistance sensor and a temperature sensor. The contact resistance sensor measures the resistance value of the corresponding contact circuit, and the temperature sensor measures the temperature at that detection point. The control unit simultaneously sends acquisition commands to all detection points, reads the real-time contact resistance value output by each contact resistance sensor, and reads the real-time temperature value output by each temperature sensor. For the detection point numbered p, the real-time contact resistance value read at the current detection moment is recorded as... Where p represents the detection point number, and the value of p ranges from 1 to M, where M is the total number of detection points; the real-time temperature value read at the same time is recorded as... .

[0032] The real-time contact resistance and real-time temperature values ​​of each detection point are paired and stored according to the detection point number. In the control unit's memory, a storage record is assigned to each detection point, containing a detection point number field, a real-time contact resistance value field, and a real-time temperature value field. The read data... and Write the values ​​into the record corresponding to the detection point number p, so that the real-time contact resistance value and the real-time temperature value are paired through the same detection point number.

[0033] In practice, for each detection point, the preset temperature coefficient of resistance for that point is looked up based on its real-time temperature value. The preset temperature coefficient of resistance is a mapping relationship between temperature and coefficient obtained through calibration experiments, stored in the control unit in the form of a lookup table or piecewise function. For the detection point numbered p, the real-time temperature value is used as the lookup table. As the input for the query, the corresponding preset resistance temperature coefficient is retrieved from the mapping relationship, denoted as . . It is a dimensionless coefficient whose value is expressed in terms of temperature. The correction factor for the contact resistance value relative to the resistance value at the reference temperature, where the preset resistance temperature coefficient at the reference temperature is set to 1.

[0034] After obtaining the preset temperature coefficient of resistance, thermal drift compensation is performed on the real-time contact resistance value. The real-time compensation resistance value is obtained by dividing the real-time contact resistance value of each detection point by the corresponding preset temperature coefficient of resistance. For the detection point numbered p, the real-time compensation resistance value is denoted as... The calculation formula is as follows: in, This represents the real-time compensation resistance value of the detection point numbered p after thermal drift compensation at the current detection time. This represents the real-time contact resistance value collected at the detection point numbered p at the current detection time; This indicates that the detection point numbered p is at the real-time temperature value. The corresponding preset temperature coefficient of resistance.

[0035] In practice, after completing the compensation calculations for all detection points, the real-time compensation resistance values ​​of all detection points are combined in order of their detection point numbers to form a real-time compensation vector. The real-time compensation vector is an M-dimensional vector, where the p-th element is the real-time compensation resistance value of the detection point numbered p. This real-time compensation vector contains the resistance values ​​of all detection points after temperature compensation at the current detection time.

[0036] See Figure 3 The horizontal axis of the graph represents the real-time temperature value of the disconnector switch detection point, in degrees Celsius (°C); the vertical axis represents the corresponding resistance value, in milliohms (mΩ). In the legend, blue dots represent real-time contact resistance values, and orange triangles represent real-time compensation resistance values ​​after thermal drift compensation. The overall data covers a temperature range from approximately -20°C to 60°C.

[0037] The real-time contact resistance value of the blue dots in the graph shows a significant upward trend with increasing temperature, gradually rising from approximately 4.2 mΩ to nearly 6.0 mΩ, reflecting a significant thermal drift phenomenon in the contact resistance with temperature changes. In the low-temperature range (-20℃ to 0℃), the resistance value is concentrated between 4.2 mΩ and 4.7 mΩ, gradually increasing with rising temperature, and the data points show some fluctuation.

[0038] The real-time compensated resistance values ​​represented by the orange triangle are relatively stable, generally ranging from 4.8 mΩ to 5.2 mΩ, demonstrating the effect of thermal drift compensation for real-time contact resistance values ​​using a preset temperature coefficient of resistance. The compensated data points show no significant trend fluctuation with temperature changes, remaining essentially stable, indicating that the compensation algorithm effectively suppresses the influence of temperature on resistance measurement.

[0039] In practical implementation, the real-time compensation resistance value of the detection point numbered q is obtained and denoted as q. Where q represents the detection point number, and the value of q ranges from 1 to M, where M is the total number of detection points. The tripping status sub-interval corresponding to the detection point with number q is obtained. The tripping status sub-interval includes a lower limit value and an upper limit value. The lower limit value is denoted as... The upper limit of the interval is denoted as The real-time compensation resistance value of the detection point numbered q. The lower limit of the interval of the tripped state sub-interval and the upper limit of the interval Compare them.

[0040] If real-time compensation resistance value Satisfies being greater than or equal to the lower limit of the interval And less than or equal to the upper limit of the interval. If the condition is met, then the detection point numbered q is determined to fall within the open state sub-interval. If the real-time compensation resistor value Less than the lower limit of the interval or greater than the upper limit of the interval. If the detection point numbered q is not within the open circuit state sub-interval, then it is determined that the detection point is not within the open circuit state sub-interval.

[0041] Perform the above comparison and judgment operation on all detection points, traversing the detection point numbers q from 1 to M, and recording the judgment result for each detection point. Set a first quantity counter, with an initial value of 0. During the traversal, whenever a detection point is determined to fall within the open state sub-interval, increment the count value of the first quantity counter by 1. After the traversal is completed, the final count value of the first quantity counter is the first quantity, which represents the number of detection points among all detection points that fall within the open state sub-interval.

[0042] In specific implementation, the closing state sub-interval corresponding to the detection point numbered q is obtained. The closing state sub-interval includes a lower limit value and an upper limit value. The lower limit value is denoted as... The upper limit of the interval is denoted as The real-time compensation resistor value of the detection point numbered q. The lower limit of the interval of the closed state sub-interval and the upper limit of the interval Compare them.

[0043] If real-time compensation resistance value Satisfies being greater than or equal to the lower limit of the interval And less than or equal to the upper limit of the interval. If the condition is met, then the detection point numbered q is determined to fall within the closed state sub-interval. If the real-time compensation resistor value Less than the lower limit of the interval or greater than the upper limit of the interval. If the detection point numbered q is not within the closed state sub-interval, then it is determined that the detection point is not within the closed state sub-interval.

[0044] Perform the above comparison and judgment operation on all detection points, traversing the detection point numbers q from 1 to M, and recording the judgment result for each detection point. Set a second count counter, with an initial value of 0. During the traversal, whenever a detection point is determined to fall within the closed state sub-interval, increment the count value of the second count counter by 1. After the traversal is completed, the final count value of the second count counter is the second count, which represents the number of detection points among all detection points that fall within the closed state sub-interval.

[0045] In practice, a first quantity and a second quantity are obtained. The first quantity and the second quantity are then compared numerically. If the first quantity is greater than the second quantity, a determination result is output, indicating that the disconnector is currently in the open position. If the second quantity is greater than the first quantity, a determination result is output, indicating that the disconnector is currently in the closed position.

[0046] In practice, the preset temperature coefficient of resistance is obtained by performing contact resistance calibration experiments on each detection point at multiple temperature calibration points and then fitting the results. The contact resistance calibration experiment is conducted during the commissioning phase after the disconnecting switch is installed. The experiment focuses on each detection point of the disconnecting switch, and each detection point is calibrated independently.

[0047] In practice, a programmable temperature control chamber and a micro-ohmmeter are configured for the contact resistance calibration experiment. The disconnect switch is placed entirely inside the programmable temperature control chamber, which has the ability to accurately control the ambient temperature within a preset temperature range. The micro-ohmmeter is connected to both ends of the contact at the test point using a four-wire measurement method. This four-wire method eliminates the influence of the lead resistance on the measured contact resistance value.

[0048] In practical implementation, for the detection point numbered r, where r ranges from 1 to M, and M is the total number of detection points, K temperature calibration points are set, where K is a positive integer greater than 1. The K temperature calibration points are arranged in ascending or descending order to cover the temperature range that may occur during the actual operation of the disconnecting switch. The temperature calibration points are selected using equal or non-equal intervals. At each temperature calibration point, the programmable temperature control chamber is started, and the ambient temperature inside the chamber is adjusted to stabilize the temperature value corresponding to that calibration point and maintained for a preset time. The preset time is set to 30 minutes to ensure that the contact temperature and the ambient temperature reach thermal equilibrium. The preset time of 30 minutes is based on the fact that, through thermal equilibrium time testing experiments, the temperature difference between the contact body and the ambient temperature decreases to within 1% of the initial temperature difference within 30 minutes, which meets the temperature stability requirements of the calibration experiment.

[0049] In practice, after the temperature inside the programmable temperature control chamber stabilizes within a preset time, the contact resistance value of the detection point numbered r at the current temperature calibration point is measured using a micro-ohmmeter. At the same temperature calibration point, the contact resistance value is measured L times consecutively, where L is a positive integer greater than 1. The arithmetic mean of the L measurements is calculated, and this arithmetic mean is used as the calibration contact resistance value of the detection point numbered r at that temperature calibration point. The above steps are repeated for each temperature calibration point to obtain K sets of data pairs between temperature values ​​and calibration contact resistance values. The temperature value corresponding to the k-th temperature calibration point is denoted as... , temperature value The measured calibrated contact resistance value is denoted as: , where k is the temperature calibration point number, and the value of k ranges from 1 to K.

[0050] In practice, the calibrated contact resistance value of the detection point numbered r at a reference temperature is used as the normalization reference, with the reference temperature selected as 20℃. The temperature value... The rated contact resistance value below Divide by the calibrated contact resistance value at the reference temperature To obtain the temperature value Corresponding preset temperature coefficient of resistance Preset temperature coefficient of resistance The calculation formula is: in, This indicates that the detection point numbered r is at a temperature value The corresponding preset temperature coefficient of resistance is a dimensionless value. This indicates that the detection point numbered r is at a temperature value The measured calibrated contact resistance value; This represents the calibrated contact resistance value measured at the reference temperature at the detection point numbered r.

[0051] In practice, K sets of data pairs are obtained for the detection point numbered r at K temperature calibration points, with each data pair containing a temperature value. and a corresponding preset temperature coefficient of resistance K sets of data pairs are used as fitting samples, and polynomial curve fitting is performed using the least squares method. The order of the fitting polynomial is set to D, where D is a positive integer greater than or equal to 1. The fitting process solves for the polynomial coefficients, ensuring that the polynomial adapts to the specified temperature value. The function value at that point and The sum of squared deviations is minimized. After fitting, the preset resistance temperature coefficient function for the detection point numbered r is obtained, denoted as... Where X represents the temperature input variable. The fitted functional relationship... The preset resistance temperature coefficient is stored in the storage unit of the detection system in the form of a piecewise function or a lookup table, serving as the basis for querying the preset resistance temperature coefficient. During subsequent detection, for the detection point numbered r, the real-time temperature value is input, and then... The corresponding preset resistance temperature coefficient can be obtained by calculation or interpolation.

[0052] See Figure 4 The horizontal axis of the graph represents temperature values ​​(unit: °C), ranging from approximately -20 °C to 80 °C, while the vertical axis represents contact resistance values ​​(unit: mΩ), ranging from approximately 8.5 mΩ to 13.5 mΩ. The graph displays the calibrated contact resistance values ​​measured at multiple temperature calibration points in scatter plot form. These scatter plots are evenly distributed around each temperature point, reflecting the minor fluctuations and measurement errors that exist during the actual measurement process.

[0053] The curve, plotted as a continuous solid red line, represents the trend of the fitted contact resistance corresponding to the preset resistance temperature coefficient function obtained by least squares polynomial fitting. The fitted curve shows an overall trend of monotonically increasing contact resistance as temperature rises, and the curve shape conforms to the expected nonlinear relationship between temperature and resistance, indicating that the fitted function can effectively reflect the law of contact resistance change with temperature.

[0054] The temperature range shown in the figure covers multiple temperature calibration points described in the above embodiment. The experiment used a programmable temperature control chamber to control the temperature range, gradually increasing from a low temperature of -20℃ to a high temperature of 80℃, ensuring coverage of the actual operating temperature environment. The scatter plots at each temperature point were obtained by averaging multiple measurements, demonstrating the accuracy and repeatability of the calibration experiment.

[0055] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for detecting the open / closed position of a disconnecting switch, characterized in that, The method includes: Obtain the first contact resistance sequence corresponding to each detection point when the disconnecting switch is in the open position, and the second contact resistance sequence corresponding to each detection point when it is in the closed position; Based on the real-time temperature values ​​at each detection point, thermal drift compensation is performed on the first contact resistance sequence and the second contact resistance sequence to obtain the first compensation sequence and the second compensation sequence. Construct the opening and closing state characteristic intervals of each detection point based on the first compensation sequence and the second compensation sequence; Collect the real-time contact resistance and temperature values ​​at each detection point of the disconnect switch at the current moment; Thermal drift compensation is performed on the real-time contact resistance value based on the real-time temperature value to obtain the real-time compensated resistance value. The current opening / closing position of the disconnecting switch is determined based on the spatial relationship between the real-time compensation resistance value and the opening / closing state characteristic interval.

2. The method for detecting the open / closed position of a disconnecting switch according to claim 1, characterized in that, The acquisition of the first contact resistance sequence corresponding to each detection point when the disconnecting switch is in the open position, and the second contact resistance sequence corresponding to each detection point when it is in the closed position, specifically includes: Each contact of the disconnector switch is equipped with an independent detection point; When the disconnecting switch is in the open position, the contact resistance value of each detection point is continuously collected at multiple sampling times to form the first contact resistance sequence corresponding to each detection point; When the disconnector is in the closed position, the contact resistance value of each detection point is continuously collected at multiple sampling times to form the second contact resistance sequence corresponding to each detection point; The number of sampling times corresponding to each detection point is the same.

3. The method for detecting the open / closed position of a disconnecting switch according to claim 2, characterized in that, The step of performing thermal drift compensation on the first contact resistance sequence and the second contact resistance sequence based on the real-time temperature values ​​at each detection point, thereby obtaining a first compensation sequence and a second compensation sequence, specifically includes: Real-time temperature values ​​at each detection point are collected simultaneously at each sampling time; Based on the real-time temperature value of each detection point at each sampling time, obtain the preset resistance temperature coefficient corresponding to that detection point at that temperature value; Divide the contact resistance value at each sampling moment in the first contact resistance sequence of each detection point by the preset resistance temperature coefficient at the corresponding sampling moment to obtain the first compensation sequence of that detection point. Divide the contact resistance value at each sampling moment in the second contact resistance sequence of each detection point by the preset resistance temperature coefficient at the corresponding sampling moment to obtain the second compensation sequence of that detection point.

4. The method for detecting the open / closed position of a disconnecting switch according to claim 3, characterized in that, The step of constructing the opening and closing state feature intervals of each detection point based on the first compensation sequence and the second compensation sequence specifically includes: Calculate the mean value of all compensation resistor values ​​in the first compensation sequence of each detection point, and use it as the tripping characteristic value of that detection point; Calculate the mean value of all compensation resistor values ​​in the second compensation sequence of each detection point, and use it as the closing characteristic value of that detection point; Add or subtract the standard deviation of the first compensation sequence of each detection point to the tripping characteristic value of that detection point to obtain the tripping state sub-interval of that detection point. Add or subtract the standard deviation of the second compensation sequence for each detection point from its closing characteristic value to obtain the closing state sub-interval for that detection point. The open and closed state sub-intervals of all detection points are merged to form the overall open state characteristic interval and the overall closed state characteristic interval.

5. A method for detecting the open / closed position of a disconnecting switch according to claim 4, characterized in that, The acquisition of real-time contact resistance and temperature values ​​at each detection point of the disconnector switch at the current moment specifically includes: At the current detection moment, the real-time contact resistance value output by the contact resistance sensor corresponding to each detection point is read simultaneously. At the current detection moment, the real-time temperature value output by the temperature sensor corresponding to each detection point is read simultaneously; The real-time contact resistance and real-time temperature values ​​of each detection point are paired and stored according to the detection point number.

6. The method for detecting the open / closed position of a disconnecting switch according to claim 5, characterized in that, The step of performing thermal drift compensation on the real-time contact resistance value based on the real-time temperature value to obtain the real-time compensated resistance value specifically includes: For each detection point, the preset resistance temperature coefficient corresponding to that detection point is queried based on the real-time temperature value of that detection point. Divide the real-time contact resistance value of each detection point by the preset resistance temperature coefficient of the corresponding detection point to obtain the real-time compensation resistance value of each detection point. The real-time compensation resistance values ​​of all detection points are combined in order of detection point number to form a real-time compensation vector.

7. A method for detecting the open / closed position of a disconnecting switch according to claim 6, characterized in that, The step of determining the current opening / closing position of the disconnecting switch based on the spatial relationship between the real-time compensation resistance value and the opening / closing state characteristic interval specifically includes: Determine whether the real-time compensation resistor value of each detection point falls within the corresponding tripping state sub-interval of the detection point, and count the number of detection points that fall within the tripping state sub-interval, which is recorded as the first number. Determine whether the real-time compensation resistor value of each detection point falls within the corresponding closing state sub-interval of the detection point, and count the number of detection points that fall within the closing state sub-interval, which is recorded as the second number. When the first quantity is greater than the second quantity, it is determined that the disconnecting switch is currently in the open position; When the second quantity is greater than the first quantity, it is determined that the disconnecting switch is currently in the closed position.

8. A method for detecting the open / closed position of a disconnecting switch according to claim 7, characterized in that, The process of determining whether the real-time compensation resistor value of each detection point falls within the corresponding tripping state sub-interval and counting the number of detection points falling within the tripping state sub-interval, denoted as the first number, specifically includes: The real-time compensation resistor value of each detection point is compared with the lower limit and upper limit of the circuit breaker state sub-interval of that detection point; If the real-time compensation resistor value is greater than or equal to the lower limit of the interval and less than or equal to the upper limit of the interval, then the detection point is determined to fall within the open state sub-interval. The first number is obtained by counting the number of detection points that fall within the open circuit state sub-interval.

9. A method for detecting the open / closed position of a disconnecting switch according to claim 7, characterized in that, The process of determining whether the real-time compensation resistor value of each detection point falls within the corresponding closing state sub-interval and counting the number of detection points falling within the closing state sub-interval, denoted as the second number, specifically includes: The real-time compensation resistor value of each detection point is compared with the lower limit and upper limit of the closing state sub-interval of that detection point; If the real-time compensation resistor value is greater than or equal to the lower limit of the interval and less than or equal to the upper limit of the interval, then the detection point is determined to fall within the closed state sub-interval. The second quantity is obtained by counting the number of detection points that fall within the closed state sub-interval among all detection points.

10. A method for detecting the open / closed position of a disconnecting switch according to claim 3, characterized in that, The preset temperature coefficient of resistance is obtained by performing contact resistance calibration experiments on each detection point at multiple temperature calibration points and then fitting the results.

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