A method and system for temperature control of a resettable explosion-proof capacitor

Abstract

This invention relates to the field of capacitor temperature control, and more particularly to a method and system for controlling the temperature of a resettable explosion-proof capacitor. The method includes: determining the processing method—either adjusting the cooling device or analyzing the operational behavior—based on temperature characterization coefficients and heat dissipation characterization coefficients; determining the driving state based on speed change reference values ​​and direction change reference values; determining the adjustment method—harmonic detection and adjustment based on driving parameters—based on the driving state; and determining the cooling method of the cooling device—either water cooling or circulating cooling—based on the harmonic amplitude and harmonic dispersion coefficient of the target segment. This invention addresses the problem of poor temperature control performance caused by the inability of temperature control methods to effectively adapt to dynamic driving states, thereby improving the temperature control effect.

Description

Technical Field

[0001] This invention relates to the field of temperature control for capacitors, and more particularly to a method and system for temperature control of a resettable explosion-proof capacitor. Background Technology

[0002] With the rapid development of the new energy vehicle industry, capacitors, due to their high power density and rapid charging and discharging characteristics, play a crucial role in automotive electric drive systems, energy recovery, and other fields. Temperature control is a core technology for ensuring the stable operation of capacitors in complex on-board environments, and its control precision directly affects the capacitor's performance degradation rate and the overall vehicle safety. However, existing temperature control technologies often suffer from poor temperature control performance when dealing with changing driving conditions because the temperature control methods cannot effectively adapt to dynamic driving states. Therefore, how to achieve accurate monitoring and dynamic regulation of capacitor temperature under complex and changing on-board conditions is a key technical challenge that urgently needs to be solved by those skilled in the art.

[0003] Chinese Patent Publication No. CN111245084A discloses a hybrid power supply device and control method based on a CAN bus that withstands surge current. The device includes: a surge capacitor module composed of an insulated-gate bipolar transistor (IGBT), a rectifier diode, a capacitor, an adjustable resistor, and a current detection module; a battery module composed of a battery, an IGBT, and a current detection module; and a main control module composed of a microcontroller. The main control module receives inputs from two current detection modules and real-time vehicle driving data acquired via the CAN bus. It controls the on / off state of each IGBT and the magnitude of the variable resistor through its outputs. The microcontroller analyzes the vehicle driving data, considering driving intentions, operating status, and working conditions, to control the charging and discharging of the capacitor. The capacitor provides a larger current to ensure stable vehicle operation. However, the above technical solution has the following problems: although it considers the influence of vehicle driving conditions on capacitor charging and discharging, it does not consider the influence of driving conditions on capacitor temperature, leading to poor adaptability of the temperature control method and consequently low temperature control accuracy. Summary of the Invention

[0004] To address this issue, the present invention provides a method and system for controlling the temperature of a recoverable explosion-proof capacitor, thereby overcoming the problem that the existing technology does not take into account the influence of driving conditions on capacitor temperature, resulting in poor adaptability of the temperature control method and consequently low temperature control accuracy.

[0005] To achieve the above objectives, the present invention provides a method for temperature control of a resettable explosion-proof capacitor, comprising:

[0006] Based on the temperature characterization coefficient and the heat dissipation characterization coefficient, the processing method is determined to be either adjusting the cooling device or analyzing the operational behavior.

[0007] During the adjustment process of the cooling device, the power of the cooling device is determined based on the difference in the heat dissipation characterization coefficient;

[0008] In the process of analyzing and processing operational behavior, the driving state is determined based on the reference values ​​for speed and direction changes, and the driving state is used to determine whether to perform harmonic detection and adjustment based on driving parameters.

[0009] When adjusting harmonic detection, the focus time is determined based on driving parameters, and the sampling strategy is determined based on the equalization coefficient of the focus time, which is to either increase the sampling frequency or dynamically adjust the sampling window.

[0010] Once the data acquisition is complete, the harmonic performance status is determined based on the harmonic amplitude and harmonic dispersion coefficient of the target segment. Based on the harmonic performance status, the cooling method of the cooling device is determined to be either water cooling or circulating cooling. When the cooling method is circulating cooling, the cycle duration ratio is determined based on the effective harmonic difference.

[0011] Furthermore, the processing method is determined based on the temperature characterization coefficient and the heat dissipation characterization coefficient;

[0012] If the temperature characterization coefficient is greater than the preset temperature characterization coefficient and the heat dissipation characterization coefficient is less than or equal to the preset heat dissipation characterization coefficient, the processing method is to adjust the cooling device.

[0013] If the temperature characterization coefficient is less than or equal to the preset temperature characterization coefficient or the heat dissipation characterization coefficient is greater than the preset heat dissipation characterization coefficient, the processing method is to analyze and process the operation behavior.

[0014] Furthermore, when adjusting the cooling device, the power of the cooling device is determined based on the difference in the heat dissipation characterization coefficient;

[0015] The difference between the power of the cooling device and the heat dissipation characterization coefficient is negatively correlated.

[0016] Furthermore, when analyzing and processing operational behavior, if the driving state is such that the speed change reference value is greater than the preset speed change reference value and the direction change reference value is greater than the preset direction change reference value, then harmonic detection and adjustment are performed based on the driving parameters.

[0017] Furthermore, during harmonic detection and adjustment, the time of interest is determined based on driving parameters, and the sampling strategy is determined based on the comparison between the equalization coefficient of the time of interest and the preset equalization coefficient.

[0018] If the equalization coefficient at the time of interest is greater than the preset equalization coefficient, the sampling strategy is to increase the sampling frequency.

[0019] If the equalization coefficient at the time of interest is less than or equal to the preset equalization coefficient, the sampling strategy is to dynamically adjust the sampling window.

[0020] Furthermore, when increasing the sampling frequency, the sampling frequency is increased based on the effective difference.

[0021] The sampling frequency and the effective difference are positively correlated;

[0022] The effective difference is the maximum value between the velocity change difference and the direction change difference.

[0023] Furthermore, when dynamically adjusting the sampling window, the paragraph category is determined based on the density of the focus time, and the adjustment method is determined based on the paragraph category;

[0024] If the paragraph category is a type of paragraph where the density of the focus time is greater than the preset density, the adjustment method is to perform transient focus sampling adjustment;

[0025] If the paragraph category is a Class II paragraph where the density of the focus time is less than or equal to the preset density, the adjustment method is to increase the window length.

[0026] Furthermore, based on the acquisition completion conditions, the harmonic performance status is determined according to the harmonic amplitude and harmonic dispersion coefficient of the target segment, and the cooling method of the cooling device is determined according to the harmonic performance status.

[0027] If the harmonic behavior is the first behavior state where the harmonic amplitude is greater than the preset harmonic amplitude and the harmonic dispersion coefficient is greater than the preset harmonic dispersion coefficient, the cooling method is water cooling.

[0028] If the harmonic behavior is the second behavior state, where the harmonic amplitude is less than or equal to the preset harmonic amplitude or the harmonic dispersion coefficient is less than or equal to the preset harmonic dispersion coefficient, the cooling method is the cyclic cooling method.

[0029] The conditions for data collection completion are that the paragraph category is determined and data collection is completed.

[0030] Furthermore, when the cooling method is a cyclic cooling method, the cycle duration ratio is determined based on the effective harmonic difference;

[0031] If the effective harmonic difference is less than the preset effective harmonic difference, the cycle duration ratio is the reference cycle duration ratio.

[0032] If the effective harmonic difference is greater than or equal to the preset effective harmonic difference, the cycle duration ratio is the value obtained after adaptive adjustment to the reference cycle duration ratio.

[0033] The present invention also provides a system for applying the temperature control method of the recoverable explosion-proof capacitor, comprising:

[0034] The data acquisition unit includes several data acquisition devices used to acquire monitoring data;

[0035] An analysis and processing unit, connected to the data acquisition unit, is used to determine the processing method—either adjusting the cooling device or analyzing the operational behavior—based on the temperature characterization coefficient and the heat dissipation characterization coefficient.

[0036] The adjustment processing unit, which is connected to the data acquisition unit and the analysis unit respectively, is used to determine the power of the cooling device based on the difference in heat dissipation characterization coefficient when adjusting the cooling device; to determine the driving state based on the speed change reference value and the direction change reference value when analyzing the driving behavior; and to determine whether to perform harmonic detection adjustment based on the driving parameters based on the driving state.

[0037] The sampling decision unit is connected to the data acquisition unit, the analysis and processing unit and the adjustment and processing unit respectively, and is used to determine the time of concern based on driving parameters, and determine the sampling strategy based on the balance coefficient of the time of concern, which is to increase the sampling frequency or to dynamically adjust the sampling window.

[0038] The cooling regulation unit is connected to the data acquisition unit, analysis and processing unit, regulation and processing unit and sampling decision unit respectively. It is used to determine the harmonic performance state based on the harmonic amplitude and harmonic dispersion coefficient of the target segment after the acquisition is completed, and to determine the cooling method of the cooling device as water cooling or cyclic cooling based on the harmonic performance state. The cyclic cooling method is determined according to the effective harmonic difference and the ratio of the cycle time.

[0039] Compared with the prior art, the beneficial effect of the present invention is that the processing method is determined according to the temperature characterization coefficient and the heat dissipation characterization coefficient in the technical solution of the present invention. The temperature characterization coefficient and the heat dissipation characterization coefficient reflect the temperature status of the capacitor in the actual scenario, and different processing methods are set accordingly. This avoids the problem that a single processing method is difficult to meet the needs of the actual scenario, which leads to the inaccuracy of subsequent temperature adjustment, and improves the accuracy of capacitor temperature control.

[0040] Furthermore, in the technical solution of this invention, when analyzing and processing operational behavior, the influence of driving speed and direction on harmonic detection and adjustment is considered. The temperature rise trend is predicted in advance through harmonic detection, avoiding the risk of overheating due to temperature feedback delay caused by relying solely on temperature feedback in the temperature control process in the prior art, thereby improving the safety of capacitor use.

[0041] Furthermore, the technical solution of this invention employs different sampling strategies based on the evenness of the distribution of attention times, making the selection of sampling strategies more consistent with actual scenarios and improving the rationality of sampling strategies. Specifically, when dynamically adjusting the sampling window, the paragraph category is determined based on the density of attention times, and the adjustment method is determined based on the paragraph category. This avoids the inability of a single adjustment method to achieve accurate data collection, which could lead to the omission of transient data, thereby improving the integrity of data collection. The dynamic acquisition strategy avoids the data redundancy problem caused by continuous high-frequency sampling, reduces data storage pressure, and thus improves the accuracy and efficiency of data collection.

[0042] Furthermore, in the technical solution of this invention, the harmonic performance state is determined based on the harmonic amplitude and harmonic dispersion coefficient of the segment, and different cooling methods of the cooling device are corresponding to the harmonic performance state. This avoids the insufficient temperature control accuracy caused by the single cooling method in the prior art. When the cooling method is a cyclic cooling method, the cycle duration ratio is dynamically adjusted according to the effective harmonic difference, and the liquid cooling duration and air cooling duration are dynamically adjusted according to the effective harmonic difference. The cyclic cooling method with the reference cycle duration ratio is the main method, and high-energy-consuming water cooling is only used when there is a high harmonic risk. Low-power cyclic cooling is used at other times, thereby reducing energy consumption. By extending the liquid cooling duration, the temperature rise can be quickly suppressed, reducing the risk of capacitor explosion due to a sharp increase in temperature. This achieves precise and efficient control of capacitor temperature. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the temperature control method for the recoverable explosion-proof capacitor of the present invention;

[0044] Figure 2 This is a flowchart illustrating how the processing method is determined based on the temperature characterization coefficient and the heat dissipation characterization coefficient according to the present invention.

[0045] Figure 3 This is a flowchart illustrating the process of determining the sampling strategy based on the equalization coefficient at the time of interest in this invention.

[0046] Figure 4 This is a unit connection diagram of the temperature control system for the recoverable explosion-proof capacitor of the present invention. Detailed Implementation

[0047] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0048] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0050] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] Please see Figures 1 to 3 As shown, the present invention provides a method for temperature control of a resettable explosion-proof capacitor, comprising:

[0052] Based on the temperature characterization coefficient and the heat dissipation characterization coefficient, the processing method is determined to be either adjusting the cooling device or analyzing the operational behavior.

[0053] During the adjustment process of the cooling device, the power of the cooling device is determined based on the difference in the heat dissipation characterization coefficient;

[0054] In the process of analyzing and processing operational behavior, the driving state is determined based on the reference values ​​for speed and direction changes, and the driving state is used to determine whether to perform harmonic detection and adjustment based on driving parameters.

[0055] When adjusting harmonic detection, the focus time is determined based on driving parameters, and the sampling strategy is determined based on the equalization coefficient of the focus time, which is to either increase the sampling frequency or dynamically adjust the sampling window.

[0056] Once the data acquisition is complete, the harmonic performance status is determined based on the harmonic amplitude and harmonic dispersion coefficient of the target segment. Based on the harmonic performance status, the cooling method of the cooling device is determined to be either water cooling or circulating cooling. When the cooling method is circulating cooling, the cycle duration ratio is determined based on the effective harmonic difference.

[0057] The application scenario of this invention is automotive capacitors, which employ both air cooling and water cooling for cyclic cooling. In this invention, air cooling is achieved through forced ventilation via the vehicle's air conditioning duct, with a fan located at the duct inlet to force in cool air and a fan at the outlet to remove hot air. Water cooling is achieved by arranging a cooling plate on the capacitor surface, with thermally conductive silicone grease filling the interface and coolant channels within the cooling plate, allowing the coolant to circulate and indirectly absorb heat, thereby reducing the capacitor temperature.

[0058] This invention provides several monitoring cycles, the duration of which can be adaptively set by the user according to actual application needs. This invention provides a value for the duration of a single monitoring cycle, which is 5 minutes.

[0059] This invention utilizes several historical records. Each historical record includes at least a weighting coefficient, a temperature characterization coefficient, a heat dissipation characterization coefficient, a speed change reference value, a direction change reference value, an equalization coefficient, a time interval, a density, a harmonic amplitude, a harmonic dispersion coefficient, and an effective harmonic difference. Each historical record is also marked with a pass / fail flag, indicating whether the historical record meets user requirements. Whether a historical record meets user requirements can be determined, but is not limited to, based on whether the maximum temperature during capacitor use meets the user's temperature requirements. Determining whether a historical record meets user requirements based on self-defined indicators is a concept already understood by those skilled in the art and is not limited here.

[0060] This invention establishes target judgment values ​​and relevant reference values. The correspondence between the target judgment values ​​and relevant reference values ​​is expressed through a calculation formula that includes an adjustment coefficient and a benchmark judgment value. The calculation formula is: Target judgment value = Benchmark judgment value + Relevant reference value × Adjustment coefficient. Specifically, the target judgment values ​​in this invention include cooling device power, window length, and cycle time ratio. The relevant reference values ​​include temperature extremes, density, and effective harmonic difference. It can be understood that each target judgment value has a corresponding relevant reference value, and each target judgment value corresponds to a benchmark judgment value, which is set by the user. Each relevant reference value also has a separate adjustment coefficient, which is set by the user. For example, the value of the adjustment coefficient corresponding to density can be set according to the user's needs. The user can determine the window length corresponding to different densities based on historical records, thereby determining the degree of influence of density on window length, and thus determining the adjustment coefficient. Different adjustment coefficients can be selected accordingly. The greater the degree of influence, the larger the adjustment coefficient. The adjustment coefficient is positive when there is a positive correlation and negative when there is a negative correlation.

[0061] Specifically, the processing method is determined based on the temperature characterization coefficient and the heat dissipation characterization coefficient;

[0062] If the temperature characterization coefficient is greater than the preset temperature characterization coefficient and the heat dissipation characterization coefficient is less than or equal to the preset heat dissipation characterization coefficient, the processing method is to adjust the cooling device.

[0063] If the temperature characterization coefficient is less than or equal to the preset temperature characterization coefficient or the heat dissipation characterization coefficient is greater than the preset heat dissipation characterization coefficient, the processing method is to analyze and process the operation behavior.

[0064] Temperature characterization coefficient = α1 × ambient temperature + α2 × capacitor temperature; where α1 is the first weighting coefficient and α2 is the second weighting coefficient. The values ​​of α1 and α2 can be set directly by the user based on domain experience, or by using statistical methods such as regression analysis or principal component analysis (PCA) to determine the contribution of ambient temperature and capacitor temperature to the temperature characterization coefficient, thereby determining the corresponding weighting coefficient values. The greater the contribution, the greater the weighting coefficient value. The weights can also be adjusted through training based on historical records (such as machine learning).

[0065] The ambient temperature is determined by setting several first detection points in the engine compartment with the capacitor location as the center and within a range of less than or equal to a preset distance from the center location. The detection temperature of several first detection points is detected in each monitoring cycle. For a single monitoring cycle, the average value of the detection temperature of all first detection points is recorded as the ambient temperature of that monitoring cycle.

[0066] The method for confirming the capacitor temperature is as follows: several second detection points are evenly set on the surface of the capacitor, thermocouples are placed at each second detection point and the thermocouples are tightly attached to the capacitor shell, connected to a temperature acquisition instrument, the temperature corresponding to several second detection points is detected, and the average value of the temperature corresponding to the second detection points is recorded as the capacitor temperature.

[0067] The preset number of the first and second detection points can be adaptively set by the user according to actual application needs. It is understood that the higher the user's requirement for the detection accuracy of the ambient temperature, the larger the preset number of the first detection points; the higher the user's requirement for the detection accuracy of the capacitor temperature, the larger the preset number of the second detection points. This invention provides a method for determining the preset number, which extracts the corresponding number of the first and second detection points from the historical records that meet the user's needs, filters out outliers, and records the average value of the number of the first and second detection points after removing outliers as the preset number of the first and second detection points, respectively. The method for filtering outliers can be, but is not limited to, the 3σ criterion method or the IQR method.

[0068] The heat dissipation characteristic coefficient = (maximum capacitor temperature - ambient temperature) / capacitor power loss; where, capacitor power loss = RMS current² × equivalent series resistance. The RMS current is determined by connecting a current probe clamp in series with the capacitor's charging and discharging circuit and directly reading the RMS current value using an oscilloscope. The equivalent series resistance is determined by directly measuring the equivalent series resistance using a digital LCR meter.

[0069] The preset temperature characterization coefficient and preset heat dissipation characterization coefficient can be adaptively set by the user according to actual needs. It is understood that both ambient temperature and heat dissipation efficiency will affect the temperature of the capacitor itself. The smaller the user's tolerance for the influence of the capacitor temperature, the smaller the preset temperature characterization coefficient and the larger the preset heat dissipation characterization coefficient. This invention provides a method for determining the preset temperature characterization coefficient and preset heat dissipation characterization coefficient, which extracts the corresponding temperature characterization coefficient and heat dissipation characterization coefficient from the historical records that meet the user's needs, filters out outliers, and records the average values ​​of the temperature characterization coefficient and heat dissipation characterization coefficient after removing outliers as the preset temperature characterization coefficient and preset heat dissipation characterization coefficient, respectively.

[0070] Specifically, when adjusting the cooling device, the power of the cooling device is determined based on the difference in the heat dissipation characterization coefficient.

[0071] The difference between the power of the cooling device and the heat dissipation characterization coefficient is negatively correlated.

[0072] The power of the cooling device = base power + k1 × heat dissipation characterization coefficient difference; where k1 is the adjustment coefficient corresponding to the heat dissipation characterization coefficient difference, and the heat dissipation characterization coefficient difference = preset heat dissipation characterization coefficient - heat dissipation characterization coefficient; the value of the base power can be adaptively set by the user according to the actual application requirements. This invention provides a method for determining the value of the base power by extracting the power of the corresponding cooling device in the historical records that meet the user's requirements, filtering out the outliers, and recording the average power of the cooling device after removing the outliers as the base power.

[0073] Specifically, when analyzing and processing driving behavior, if the driving state is such that the speed change reference value is greater than the preset speed change reference value and the direction change reference value is greater than the preset direction change reference value, then harmonic detection and adjustment are performed based on the driving parameters.

[0074] A driving state in which the speed change reference value is less than or equal to the preset speed change reference value or the direction change reference value is less than or equal to the preset direction change reference value is considered a qualified driving state, and no adjustment is required for a qualified driving state.

[0075] The method for confirming the speed change reference value is as follows: several time point detection points are evenly set within the monitoring period, the speed curve corresponding to the vehicle within the monitoring period is extracted, the slope of the detection point at each time point on the speed curve is detected, and the average value of the slopes corresponding to all time point detection points is recorded as the speed change reference value.

[0076] The method for confirming the direction change reference value is as follows: the center position of the steering wheel when the vehicle is traveling straight is recorded as the zero position; the angle of rotation of the steering wheel from the zero position to the left or right is recorded as the left rotation angle and the right rotation angle, respectively; the maximum left rotation angle and the maximum right rotation angle within each time period are detected; and the average angle is recorded as the steering wheel angle change value for that time period. The time period is determined by a fixed duration centered on the time corresponding to each detection point. The user can adaptively set the value of the fixed duration according to actual needs. It is understood that the higher the accuracy requirement of the direction change reference value, the larger the fixed duration value. This invention provides a fixed duration value: fixed duration = 3s; average angle = (maximum left rotation angle + maximum right rotation angle) / 2; the average value of the steering wheel angle change values ​​for all time periods within a single cycle is recorded as the direction change reference value.

[0077] The preset number of time detection points can be set by the user according to the actual application requirements. It is understood that the higher the accuracy requirements of the speed change reference value and the direction change reference value, the larger the preset number of time detection points will be. This invention provides a method for setting the preset number of time detection points, which extracts the corresponding number of time detection points in the historical records that meet the user's requirements, filters out the outliers, and records the average number of time detection points after removing the outliers as the preset number of time detection points.

[0078] The method for determining the preset speed change reference value and the preset direction change reference value allows users to adaptively set them according to their actual needs. It is understood that during driving, the faster the speed and direction change, the greater the impact on capacitor temperature control. Therefore, the lower the user's tolerance for the impact on capacitor temperature control, the smaller the preset speed change reference value and the smaller the preset direction change reference value. This invention provides a method for determining the preset speed change reference value and the preset direction change reference value. It extracts the corresponding speed change reference value and direction change reference value from historical records that meet the user's needs, filters out outliers, and records the average values ​​of the speed change reference value and direction change reference value after removing outliers as the preset speed change reference value and preset direction change reference value, respectively.

[0079] Specifically, during harmonic detection and adjustment, the focus time is determined based on driving parameters, and the sampling strategy is determined based on the comparison between the equalization coefficient of the focus time and the preset equalization coefficient.

[0080] If the equalization coefficient at the time of interest is greater than the preset equalization coefficient, the sampling strategy is to increase the sampling frequency.

[0081] If the equalization coefficient at the time of interest is less than or equal to the preset equalization coefficient, the sampling strategy is to dynamically adjust the sampling window.

[0082] Driving parameters include speed change reference values ​​and direction change reference values. The moment when both the speed change reference value and the direction change reference value are greater than a preset speed change reference value are recorded as the focus moment. The equalization coefficient is determined by detecting the time interval between each focus moment. Let Δti represent the time interval between the i-th focus moment and the (i+1)-th focus moment. The equalization coefficient = ;in, = Total duration of a single monitoring cycle / (N-1), where N-1 is the number of time intervals within a single monitoring cycle.

[0083] The user can adaptively set the value of the preset equalization coefficient according to the actual application requirements. It can be understood that the greater the impact of the distribution state at the time of focus on the sampling strategy, the smaller the preset equalization coefficient will be. This invention provides a method for setting the value of the preset equalization coefficient, which extracts the corresponding equalization coefficient from the historical records that meet the user's needs, filters out outliers, and records the average value of the equalization coefficient after removing outliers as the preset equalization coefficient.

[0084] Specifically, when increasing the sampling frequency, the sampling frequency is increased based on the effective difference.

[0085] The sampling frequency and the effective difference are positively correlated;

[0086] The effective difference is the maximum value between the velocity change difference and the direction change difference.

[0087] Sampling frequency = k2 × effective difference; where k2 is the adjustment coefficient corresponding to the effective difference, velocity change difference = velocity change reference value - preset velocity change reference value, direction change difference = direction change reference value - preset direction change reference value.

[0088] Specifically, when dynamically adjusting the sampling window, the paragraph category is determined based on the density of the focus time, and the adjustment method is determined based on the paragraph category;

[0089] If the paragraph category is a type of paragraph where the density of the focus time is greater than the preset density, the adjustment method is to perform transient focus sampling adjustment;

[0090] If the paragraph category is a Class II paragraph where the density of the focus time is less than or equal to the preset density, the adjustment method is to increase the window length.

[0091] The target set is constructed based on the time interval between two adjacent moments of interest. Taking the first moment of interest within the monitoring period as the starting moment, the time interval between it and the second moment of interest is detected. If the time interval is less than a preset time interval, both the starting moment and the second moment of interest are recorded in the target set. If the time interval is greater than or equal to the preset time interval, the starting moment is not recorded in the target set, and the time interval detection continues with the second moment of interest as the starting moment until the detected time interval is greater than or equal to the preset time interval. At this point, the target set is established. Then, taking the first moment of interest in the time sequence that is not recorded in the target set as the starting moment, the time interval detection and target set establishment continue until the target set covers all moments of interest, and the time interval between any two adjacent moments of interest in the target set is less than the preset time interval. For a single target set, its density = the total duration corresponding to the target set / the number of target moments in the target set.

[0092] The user can adaptively set the value of the preset time interval according to actual needs. It is understood that the greater the influence of the time interval on the paragraph category, the smaller the value of the preset time interval. This invention provides a method for setting the preset time interval by extracting the corresponding time interval from the historical records that meet the user's needs, filtering out outliers, and recording the average value of the time intervals after removing outliers as the preset time interval.

[0093] The preset density value can be set adaptively by the user according to actual needs. It can be understood that the greater the influence of paragraph category on the adjustment method, the smaller the preset density value. This invention provides a method for setting the preset density value by extracting the corresponding density from the historical records that meet the user's needs, filtering out outliers, and recording the average density after removing outliers as the preset density.

[0094] During transient focusing and sampling adjustment, if the time interval between two points of interest is less than the average time interval, the number of sampling times between the two points of interest is increased. The user can adaptively set the number of sampling times according to the actual application requirements. It can be understood that the higher the user's requirements for the temperature control accuracy of the capacitor, the greater the increase in the number of sampling times. This invention provides a method for determining the value of the increase in the number of sampling times. In this invention, the increase in the number of sampling times is (average time interval - time interval) × the existing number of sampling times within the segment.

[0095] Specifically, based on the acquisition completion conditions, the harmonic performance status is determined according to the harmonic amplitude and harmonic dispersion coefficient of the target segment, and the cooling method of the cooling device is determined according to the harmonic performance status.

[0096] If the harmonic behavior is the first behavior state where the harmonic amplitude is greater than the preset harmonic amplitude and the harmonic dispersion coefficient is greater than the preset harmonic dispersion coefficient, the cooling method is water cooling.

[0097] If the harmonic behavior is the second behavior state, where the harmonic amplitude is less than or equal to the preset harmonic amplitude or the harmonic dispersion coefficient is less than or equal to the preset harmonic dispersion coefficient, the cooling method is the cyclic cooling method.

[0098] The conditions for data collection completion are that the paragraph category is determined and data collection is completed.

[0099] The capacitor's current value is affected by harmonic currents, causing the capacitor to generate additional heat and thus increase its temperature. The distribution of hot spots, whether local hot spots or overall temperature rise, is determined by analyzing the harmonic behavior of the segment. The harmonic amplitude is confirmed by extracting the harmonic variation curve corresponding to the target segment, obtaining the fundamental frequency peak value in the spectrum diagram for fundamental frequency location, recording the harmonic position at the integer multiple of the fundamental frequency, and recording the peak value corresponding to the harmonic position as the harmonic amplitude.

[0100] The harmonic dispersion coefficient is determined as follows: Harmonic dispersion coefficient = Where M is the number of harmonics occurring within a single period. Let z be the amplitude corresponding to the i-th harmonic, and z be the average value of the harmonic amplitude within a single period.

[0101] Users can adaptively set the preset harmonic amplitude and preset harmonic dispersion coefficient according to actual application needs. It is understood that the greater the influence of harmonic performance on the cooling method, the smaller the preset harmonic amplitude and the smaller the preset harmonic dispersion coefficient. This invention provides a method for setting the preset harmonic amplitude and preset harmonic dispersion coefficient, which extracts the corresponding harmonic amplitude and harmonic dispersion coefficient from the historical records that meet the user's needs, filters out outliers, and records the average values ​​of the harmonic amplitude and harmonic dispersion coefficient after removing outliers as the preset harmonic amplitude and preset harmonic dispersion coefficient, respectively.

[0102] Specifically, when the cooling method is a cyclic cooling method, the cycle duration ratio is determined based on the effective harmonic difference;

[0103] If the effective harmonic difference is less than the preset effective harmonic difference, the cycle duration ratio is the reference cycle duration ratio.

[0104] If the effective harmonic difference is greater than or equal to the preset effective harmonic difference, the cycle duration ratio is the value obtained after adaptive adjustment to the reference cycle duration ratio.

[0105] The effective harmonic difference is the larger of the harmonic amplitude difference and the harmonic dispersion coefficient difference, wherein the harmonic amplitude difference = preset harmonic amplitude - harmonic amplitude, and the harmonic dispersion coefficient difference = preset harmonic dispersion coefficient - harmonic dispersion coefficient; the cycle duration ratio = water cooling duration / air cooling duration;

[0106] The method to increase the cycle time ratio is to extend the water cooling time to increase the cycle time ratio. The value of the extended time can be adaptively set by the user according to the actual application requirements. It can be understood that the higher the user's requirements for temperature control accuracy, the longer the water cooling extended time will be. This invention provides a value for the extended time: extended time = 0.2 × water cooling time.

[0107] The preset effective harmonic difference value can be adaptively set by the user according to the actual application requirements. It can be understood that the greater the influence of the effective harmonic difference value on the dynamic adjustment of the cycle duration ratio, the smaller the preset effective harmonic difference value will be. This invention provides a method for setting the preset effective harmonic difference value, which extracts the corresponding effective harmonic difference value in the historical records that meet the user's requirements, filters out the outliers, and records the average value of the effective harmonic difference value after removing the outliers as the preset effective harmonic difference value.

[0108] Please see Figure 4 The diagram shown is a unit connection diagram of the resettable explosion-proof capacitor temperature control system of the present invention. The present invention also provides a resettable explosion-proof capacitor temperature control system, comprising:

[0109] The data acquisition unit includes several data acquisition devices used to acquire monitoring data;

[0110] An analysis and processing unit, connected to the data acquisition unit, is used to determine the processing method—either adjusting the cooling device or analyzing the operational behavior—based on the temperature characterization coefficient and the heat dissipation characterization coefficient.

[0111] The adjustment processing unit, which is connected to the data acquisition unit and the analysis unit respectively, is used to determine the power of the cooling device based on the difference in heat dissipation characterization coefficient when adjusting the cooling device; to determine the driving state based on the speed change reference value and the direction change reference value when analyzing the driving behavior; and to determine whether to perform harmonic detection adjustment based on the driving parameters based on the driving state.

[0112] The sampling decision unit is connected to the data acquisition unit, the analysis and processing unit and the adjustment and processing unit respectively. It is used to determine the time of concern based on driving parameters, determine the distribution state based on the balance coefficient of the time of concern, and determine the sampling strategy based on the distribution state, which is to increase the sampling frequency or dynamically adjust the sampling window.

[0113] The cooling regulation unit is connected to the data acquisition unit, analysis and processing unit, regulation and processing unit and sampling decision unit respectively. It is used to determine the harmonic performance state based on the harmonic amplitude and harmonic dispersion coefficient of the target segment after the acquisition is completed, and to determine the cooling method of the cooling device as water cooling or cyclic cooling based on the harmonic performance state. The cyclic cooling method determines the cycle time ratio based on the effective harmonic difference.

[0114] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for temperature control of a resettable explosion-proof capacitor, characterized in that, include: Based on the temperature characterization coefficient and the heat dissipation characterization coefficient, the processing method is determined to be either adjusting the cooling device or analyzing the operational behavior. During the adjustment process of the cooling device, the power of the cooling device is determined based on the difference in the heat dissipation characterization coefficient; In the process of analyzing and processing operational behavior, the driving state is determined based on the reference values ​​for speed and direction changes, and the driving state is used to determine whether to perform harmonic detection and adjustment based on driving parameters. When adjusting harmonic detection, the focus time is determined based on driving parameters, and the sampling strategy is determined based on the equalization coefficient of the focus time, which is to either increase the sampling frequency or dynamically adjust the sampling window. Under the condition that the acquisition is completed, the harmonic performance status is determined according to the harmonic amplitude and harmonic dispersion coefficient of the target segment, and the cooling method of the cooling device is determined to be either water cooling or circulating cooling based on the harmonic performance status. When the cooling method is circulating cooling, the cycle duration ratio is determined according to the effective harmonic difference. The moment when the driving state is such that both the speed change reference value and the direction change reference value are greater than the preset direction change reference value is recorded as the focus moment. The equalization coefficient is determined by detecting the time interval between each focus moment. Let Δti represent the time interval between the i-th focus moment and the (i+1)-th focus moment, and the equalization coefficient = ;in, =Total duration of a single monitoring cycle / (N-1), where N-1 is the number of time intervals within a single monitoring cycle; The harmonic dispersion coefficient is determined as follows: Harmonic dispersion coefficient = Where M is the number of harmonics occurring within a single period. Let z be the amplitude corresponding to the i-th harmonic, and z be the average value of the harmonic amplitude within a single period; The effective harmonic difference is the larger of the harmonic amplitude difference and the harmonic dispersion coefficient difference; Difference in heat dissipation characterization coefficient = Preset heat dissipation characterization coefficient - Heat dissipation characterization coefficient.

2. The temperature control method for a resettable explosion-proof capacitor according to claim 1, characterized in that, The processing method is determined based on the temperature characterization coefficient and the heat dissipation characterization coefficient. If the temperature characterization coefficient is greater than the preset temperature characterization coefficient and the heat dissipation characterization coefficient is less than or equal to the preset heat dissipation characterization coefficient, the processing method is to adjust the cooling device. If the temperature characterization coefficient is less than or equal to the preset temperature characterization coefficient or the heat dissipation characterization coefficient is greater than the preset heat dissipation characterization coefficient, the processing method is to analyze and process the operation behavior.

3. The temperature control method for a resettable explosion-proof capacitor according to claim 2, characterized in that, When adjusting the cooling device, the power of the cooling device is determined based on the difference in the heat dissipation characterization coefficient; The power of the cooling device = base power + k1 × difference in heat dissipation characterization coefficient.

4. The temperature control method for a resettable explosion-proof capacitor according to claim 2, characterized in that, When analyzing and processing driving behavior, if the driving state is such that the speed change reference value is greater than the preset speed change reference value and the direction change reference value is greater than the preset direction change reference value, then harmonic detection and adjustment are performed based on the driving parameters.

5. The temperature control method for a resettable explosion-proof capacitor according to claim 4, characterized in that, When adjusting harmonic detection, the focus time is determined based on driving parameters, and the sampling strategy is determined based on the comparison between the equalization coefficient of the focus time and the preset equalization coefficient. If the equalization coefficient at the time of interest is greater than the preset equalization coefficient, the sampling strategy is to increase the sampling frequency. If the equalization coefficient at the time of interest is less than or equal to the preset equalization coefficient, the sampling strategy is to dynamically adjust the sampling window.

6. The temperature control method for a resettable explosion-proof capacitor according to claim 5, characterized in that, When increasing the sampling frequency, the sampling frequency is increased based on the effective difference. The sampling frequency and the effective difference are positively correlated; The effective difference is the maximum value between the velocity change difference and the direction change difference; Speed ​​change difference = speed change reference value - preset speed change reference value; direction change difference = direction change reference value - preset direction change reference value.

7. The temperature control method for a resettable explosion-proof capacitor according to claim 6, characterized in that, When dynamically adjusting the sampling window, the paragraph category is determined based on the density of the time of interest, and the adjustment method is determined based on the paragraph category. If the paragraph category is a type of paragraph where the density of the focus time is greater than the preset density, the adjustment method is to perform transient focus sampling adjustment; If the paragraph category is a Class II paragraph where the density of the focus time is less than or equal to the preset density, the adjustment method is to increase the window length.

8. The temperature control method for a resettable explosion-proof capacitor according to claim 7, characterized in that, Based on the acquisition completion conditions, the harmonic performance status is determined according to the harmonic amplitude and harmonic dispersion coefficient of the target segment, and the cooling method of the cooling device is determined according to the harmonic performance status. If the harmonic behavior is the first behavior state where the harmonic amplitude is greater than the preset harmonic amplitude and the harmonic dispersion coefficient is greater than the preset harmonic dispersion coefficient, the cooling method is water cooling. If the harmonic behavior is the second behavior state, where the harmonic amplitude is less than or equal to the preset harmonic amplitude or the harmonic dispersion coefficient is less than or equal to the preset harmonic dispersion coefficient, the cooling method is the cyclic cooling method. The conditions for data collection completion are that the paragraph category is determined and data collection is completed.

9. The temperature control method for a resettable explosion-proof capacitor according to claim 8, characterized in that, When the cooling method is cyclic cooling, the cycle duration ratio is determined based on the effective harmonic difference. If the effective harmonic difference is less than the preset effective harmonic difference, the cycle duration ratio is the reference cycle duration ratio. If the effective harmonic difference is greater than or equal to the preset effective harmonic difference, the cycle duration ratio is the value obtained after adaptive adjustment to the reference cycle duration ratio.

10. A system applying the temperature control method for a resettable explosion-proof capacitor according to any one of claims 1 to 9, characterized in that, include: The data acquisition unit includes several data acquisition devices used to acquire monitoring data; An analysis and processing unit, connected to the data acquisition unit, is used to determine the processing method—either adjusting the cooling device or analyzing the operational behavior—based on the temperature characterization coefficient and the heat dissipation characterization coefficient. An adjustment processing unit, which is connected to the data acquisition unit and the analysis processing unit respectively, is used to determine the power of the cooling device based on the difference in the heat dissipation characterization coefficient when adjusting the cooling device. When analyzing and processing operational behavior, the driving state is determined based on speed change reference values ​​and direction change reference values; and based on the driving state, it is determined whether to perform harmonic detection and adjustment according to driving parameters. The sampling decision unit is connected to the data acquisition unit, the analysis and processing unit and the adjustment and processing unit respectively, and is used to determine the time of concern based on driving parameters, and determine the sampling strategy based on the balance coefficient of the time of concern, which is to increase the sampling frequency or to dynamically adjust the sampling window. The cooling regulation unit is connected to the data acquisition unit, analysis and processing unit, regulation and processing unit and sampling decision unit respectively. It is used to determine the harmonic performance state based on the harmonic amplitude and harmonic dispersion coefficient of the target segment after the acquisition is completed, and to determine the cooling method of the cooling device as water cooling or cyclic cooling based on the harmonic performance state. The cyclic cooling method determines the cycle time ratio based on the effective harmonic difference.

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