Discharge resistance evaluation method and device, electronic equipment and storage medium

Abstract

Embodiments of the present application relate to a discharge resistance evaluation method and device, electronic equipment and storage medium, comprising: obtaining parameter information required for evaluating a target discharge resistance, then determining the capacitance and resistance of each branch in the target object according to the charging process, iterating the discharge resistance according to a preset unit resistance value, inputting the discharge resistance and other required parameters into a pre-constructed first state model and second state model in each iteration period, determining the maintenance time corresponding to the discharge resistance of the iteration period, determining the maintenance time corresponding to the discharge resistance in each iteration period, and then obtaining the corresponding relationship between the maintenance time and the discharge resistance, and determining the target discharge resistance according to the given target maintenance time and the corresponding relationship between the maintenance time and the discharge resistance. In this way, the target discharge resistance corresponding to any maintenance time can be quickly determined, especially for the working conditions with limited maintenance time, which has extremely high application value.

Description

Technical Field

[0001] The present invention relates to the field of electronic and electrical technology, and in particular to a method, apparatus, electronic device and storage medium for evaluating discharge resistance. Background Technology

[0002] Supercapacitor energy storage systems have become a hot topic in addressing the problem of brake energy recovery in urban rail trains. Due to the nonlinear and charge redistribution characteristics of supercapacitors, discharge using a fixed resistor takes significantly longer than equivalent analysis under linear characteristics. Furthermore, after discharge ceases, charge redistribution causes the voltage to rebound rapidly, exceeding the system's safe voltage. This operational characteristic makes routine maintenance and repair of supercapacitor energy storage systems a major challenge. Currently, supercapacitor systems typically employ long-duration discharge using a fixed resistor, extending the discharge time to achieve the desired discharge. However, subway systems allow limited maintenance and repair time for supercapacitor energy storage systems, and the system must not be exposed to a power source exceeding its safe voltage during maintenance and repair. Therefore, long-duration discharge is unsuitable for this application.

[0003] Another approach employs multi-stage resistor switching, switching the resistance value by connecting equal-value resistors in parallel. When the voltage is relatively high, a large resistor is used for discharge to prevent excessive discharge power; when the voltage is low, a small resistor is used to increase the discharge rate. This method can achieve short-term discharge, but it requires additional control units and more complex detection, control, and protection logic. It also requires more contactors and a larger design space, posing significant challenges to design and cost. Furthermore, after rapid discharge, the voltage rebound is faster, easily exceeding the safe voltage threshold.

[0004] Currently, there is no technology to design discharge resistors based on the nonlinear characteristics and charge redistribution characteristics of supercapacitors in applications requiring short-term discharge. This problem urgently needs to be solved. Summary of the Invention

[0005] This application provides a method, apparatus, electronic device, and storage medium for evaluating discharge resistance, in order to solve all or part of the problems in the prior art.

[0006] In a first aspect, this application provides a method for evaluating discharge resistance, the method comprising:

[0007] The target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage at the start of charging the target object with the rated current, the second voltage corresponding to the first preset charging time, the third voltage corresponding to the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the ratio of branch time constants are obtained.

[0008] Based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the ratio of the branch time constant, determine the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance coefficient of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch in the target object other than the first branch. The first branch is the first branch in the target object.

[0009] Based on the maximum allowable maintenance time, rated capacitance, third voltage, and discharge cutoff voltage, determine the resistance range of the discharge resistor for discharging the target object.

[0010] The discharge resistor is iterated within a preset unit resistance range to obtain the discharge resistor corresponding to each iteration cycle.

[0011] The third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except the first branch are input into the pre-constructed first state model and iterated from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time when the initial voltage is reached. The first discharge resistance is the discharge resistance in the current iteration cycle.

[0012] The initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitance and resistance corresponding to each branch of the target object except the first branch are input into the pre-constructed second state model and iteratively processed from the initial iteration time. When the terminal voltage of the target object reaches the first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor.

[0013] The resistance value of the target discharge resistor of the target object is evaluated based on the target maintenance time, each discharge resistor, and the first target time corresponding to each discharge resistor.

[0014] This method first obtains the parameter information required to evaluate the target discharge resistance. Then, based on the charging process, it determines the capacitance and resistance of each branch in the target object. The discharge resistance is iterated according to a preset unit resistance value. In each iteration cycle, the discharge resistance and other required parameters are input into a pre-constructed first-state model and a second-state model to determine the first target time, i.e., the maintenance time, corresponding to the discharge resistance in this iteration cycle. By determining the maintenance time corresponding to the discharge resistance in each iteration cycle, the correspondence between maintenance time and discharge resistance can be obtained. Therefore, after determining the target maintenance time, the target discharge resistance can be determined based on the target maintenance time and the correspondence between maintenance time and discharge resistance. This method first sets the parameters of the nonlinear circuit model based on the charging process, making it more consistent with the operating conditions of nonlinear circuits. It uses numerical iteration to solve the discharge process and charge redistribution process of the nonlinear circuit model, and can quickly evaluate the discharge resistance that meets both the operating condition safety (first preset condition) and the target maintenance time. It is applicable to any maintenance condition, especially suitable for short-term maintenance conditions using supercapacitor energy storage systems as energy recovery systems, and has extremely high application value.

[0015] In conjunction with the first aspect, in a first embodiment of the first aspect of the present invention, based on the rated current, the first sub-capacitor of the first branch in the target object, the capacitance coefficient corresponding to the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance corresponding to each branch in the target object other than the first branch are determined, including:

[0016] The resistance of the first branch is determined based on the third voltage, the fourth voltage, and the rated current.

[0017] The first sub-capacitor is determined based on the rated current, the first preset charging time, the first voltage, and the second voltage;

[0018] The capacitance coefficient is determined based on the first sub-capacitor, the rated current, the second preset charging time, and the third voltage.

[0019] Based on the first branch resistance, the first sub-capacitor, the third voltage, and the ratio of branch time constants, determine the branch voltage corresponding to each branch in the target object;

[0020] The capacitance of the i-th branch is determined based on the branch voltage corresponding to the i-th branch, the capacitance, rated current, second preset charging time, first voltage, and capacitance coefficient of the first branch.

[0021] The resistance of the i-th branch is determined based on the capacitance of the i-th branch and the time constant corresponding to the i-th branch, where i is a positive integer greater than or equal to 2.

[0022] This method allows for the determination of the capacitance coefficients of the first sub-capacitor of the first branch and the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch other than the first branch in the target object, based on the parameter information during the charging process. This provides data support for subsequent state modeling.

[0023] In conjunction with the first embodiment of the first aspect, in the second embodiment of the first aspect of the present invention, the third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except the first branch are input into a pre-constructed first state model for iterative processing from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time at which the initial voltage is reached, including:

[0024] The third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except the first branch are input into the pre-constructed first state model and iterate from the initial discharge time to obtain the terminal voltage of the target object and the branch voltage of each branch at each time.

[0025] When the terminal voltage reaches the second preset condition, the current time is confirmed as the initial iteration time, and the branch voltage of the j-th branch is confirmed as the initial voltage, where the j-th branch is any one of the branches of the target object, and j is a positive integer.

[0026] By substituting the parameters during the discharge process into a pre-constructed first-state model, the branch voltage of each branch and the terminal voltage of the target object can be obtained when the discharge reaches the second preset condition. This allows the determination of the initial voltage of each branch, which in turn determines the input to the second-state model, ensuring the accuracy of the evaluation results.

[0027] In conjunction with any embodiment of the first aspect to the second embodiment of the first aspect, in the third embodiment of the first aspect of the present invention, the initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitor and resistor corresponding to each branch of the target object except the first branch are input to a pre-constructed second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches the first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is determined to be the first target time corresponding to the first discharge resistor, including:

[0028] Based on the first discharge resistor, capacitance coefficient, first sub-capacitor, first branch resistance, and the capacitance and resistance of each branch in the target object except the first branch, construct the charge redistribution state matrix.

[0029] The initial voltage of the second state and the charge redistribution state matrix are input into the second state model and iterated from the initial iteration time to obtain the branch voltage corresponding to each branch at each time in the charge redistribution state.

[0030] Based on the branch voltage, branch capacitance, and branch resistance of the kth branch at each moment, determine the terminal voltage of the target object at each moment, where the kth branch is any one of the branches of the target object.

[0031] When the terminal voltage reaches the second preset condition, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor.

[0032] In this way, when the target object reaches the second state, the parameters corresponding to the second state are input into the pre-constructed second state model for iteration. The branch voltage corresponding to each payment at each moment can be determined, thereby determining the terminal voltage corresponding to the target object at each moment. When the terminal voltage reaches the first preset condition, such as a preset safe voltage threshold, the time from the start of discharge to reaching the first preset condition is determined to be the first target time, which is the maintenance time. This provides a data basis for subsequently constructing the correspondence between maintenance time and discharge resistance.

[0033] In conjunction with the third embodiment of the first aspect, in the fourth embodiment of the first aspect of the present invention, the resistance value of the target discharge resistor of the target object is evaluated based on the target maintenance time, each discharge resistor, and the first target time corresponding to each discharge resistor, including:

[0034] By performing curve fitting on each discharge resistor and its corresponding first target time, a maintenance time model is obtained.

[0035] Based on the target maintenance time and the maintenance time model, the discharge resistance of the target object is estimated to obtain the target discharge resistance of the target object.

[0036] By using this method, and through curve fitting, the maintenance time model can be determined, thus maximizing the accuracy of the model.

[0037] In conjunction with any of the embodiments of the first aspect to the second embodiment of the first aspect or the fourth embodiment of the first aspect, in the fifth embodiment of the first aspect of the present invention, the method further includes:

[0038] When the terminal voltage reaches the second preset condition, the time between the initial discharge time and the time when the second preset condition is reached is confirmed as the second target time corresponding to the first discharge resistor.

[0039] By performing curve fitting on each first target time and its corresponding second target time, a discharge time model is obtained.

[0040] The first target time for the target object is estimated based on the target maintenance time and discharge time model, so as to evaluate the start time of maintenance of the target object based on the first target time.

[0041] This method can also determine the discharge end time of the target object, which can be used as a data reference during the maintenance process.

[0042] In conjunction with the fifth embodiment of the first aspect, in the sixth embodiment of the first aspect of the invention, the method further includes:

[0043] Obtain the number of parallel and series connections of the target objects in the target object system;

[0044] The system discharge resistance of the supercapacitor system is determined based on the target discharge resistance, the number of parallel connections, and the number of series connections.

[0045] This method allows for the determination of the system discharge resistance of the target system based on the number of series and parallel connections of each target object in the system. It enables the rapid and accurate determination of the discharge resistance of the target system and is of great significance in system-level applications.

[0046] Secondly, this application provides a discharge resistance evaluation device, which includes: an acquisition module, a processing module, a determination module, a first iteration module, a second iteration module, a third iteration module, and an evaluation module;

[0047] The acquisition module is used to acquire the target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage when charging the target object with the rated current begins, the second voltage corresponding to the first preset charging time, the third voltage corresponding to the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the branch time constant ratio.

[0048] The processing module is used to determine the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance coefficient of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch in the target object, excluding the first branch, based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the ratio of the branch time constants. The first branch is the first branch in the target object.

[0049] The determination module is used to determine the resistance range of the discharge resistor for discharging the target object based on the maximum allowable maintenance time, rated capacitance, third voltage, and discharge cutoff voltage.

[0050] The first iteration module is used to iterate the discharge resistor within a preset unit resistance range to obtain the discharge resistor corresponding to each iteration cycle.

[0051] The second iteration module is used to input the third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except the first branch into the pre-constructed first state model for iterative processing from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time when the initial voltage is reached. The first discharge resistance is the discharge resistance in the current iteration cycle.

[0052] The third iteration module is used to input the initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitance and resistance corresponding to each branch in the target object except the first branch into the pre-built second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches the first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor.

[0053] The evaluation module is used to evaluate the resistance value of the target discharge resistor of the target object based on the target maintenance time, each discharge resistor, and the first target time corresponding to each discharge resistor.

[0054] Optionally, the device includes:

[0055] The determination module is specifically used to: determine the resistance of the first branch based on the third voltage, the fourth voltage, and the rated current; determine the first sub-capacitor based on the rated current, the first preset charging time, the first voltage, and the second voltage; determine the capacitance coefficient based on the first sub-capacitor, the rated current, the second preset charging time, and the third voltage; determine the branch voltage corresponding to each branch in the target object based on the ratio of the first branch resistance, the first sub-capacitor, the third voltage, and the branch time constant; determine the capacitance of the i-th branch based on the branch voltage corresponding to the i-th branch, the capacitance, rated current, second preset charging time, first voltage, and the capacitance coefficient of the branches preceding the i-th branch; and determine the resistance of the i-th branch based on the capacitance of the i-th branch and the time constant corresponding to the i-th branch, where i is a positive integer greater than or equal to 2.

[0056] Optionally, the device may also include: an input module and a determination module;

[0057] The input module is used to input the third voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitance and resistance corresponding to each branch in the target object except the first branch into the pre-built first state model to iterate from the initial discharge time to obtain the terminal voltage of the target object and the branch voltage of each branch at each time.

[0058] The determination module is used to confirm that the current time is the initial iteration time when the terminal voltage reaches the second preset condition, and to confirm that the branch voltage of the j-th branch is the initial voltage, where the j-th branch is any one of the branches of the target object, and j is a positive integer.

[0059] Optionally, the device may also include: a building module;

[0060] The module is used to construct a charge redistribution state matrix based on the first discharge resistor, capacitance coefficient, first sub-capacitor, first branch resistance, and the capacitance and resistance of each branch in the target object except the first branch.

[0061] The input module is also used to input the initial voltage of the second state and the charge redistribution state matrix into the second state model for iterative processing from the initial iteration time, and to obtain the branch voltage corresponding to each branch at each time in the charge redistribution state.

[0062] The determination module is also used to determine the terminal voltage of the target object at each time step based on the branch voltage, branch capacitance, and branch resistance of the kth branch at each time step, wherein the kth branch is any one of the branches of the target object.

[0063] The confirmation module is also used to confirm, when the terminal voltage reaches the first preset condition, the time between the start of the initial discharge time and the time when the first preset condition is reached as the first target time corresponding to the first discharge resistor.

[0064] Optionally, the device may also include: a curve fitting module;

[0065] The curve fitting module is used to perform curve fitting on each discharge resistor and its corresponding first target time to obtain the maintenance time model.

[0066] The processing module is also used to estimate the discharge resistance of the target object based on the target maintenance time and the maintenance time model, and to obtain the target discharge resistance of the target object.

[0067] Optionally, the device includes:

[0068] The confirmation module is also used to confirm that when the terminal voltage reaches the second preset condition, the time between the initial discharge time and the time when the second preset condition is reached is the second target time corresponding to the first discharge resistor.

[0069] The curve fitting module is also used to perform curve fitting on each first target time and its corresponding second target time to obtain the discharge time model;

[0070] The evaluation module is also used to estimate the first target time of the target object based on the target maintenance time and the discharge time model, so as to evaluate the start time of maintenance of the target object based on the first target time.

[0071] Optionally, the device includes:

[0072] The acquisition module is also used to acquire the number of parallel and series connections of target objects in the target object system;

[0073] The determination module is also used to determine the system discharge resistance of the supercapacitor system based on the target discharge resistance, the number of parallel connections, and the number of series connections.

[0074] Thirdly, an electronic device is provided, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0075] Memory, used to store computer programs;

[0076] When a processor executes a program stored in a memory, it implements the steps of the discharge resistance evaluation method according to any embodiment of the first aspect.

[0077] Fourthly, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the discharge resistance evaluation method as described in any embodiment of the first aspect. Attached Figure Description

[0078] Figure 1 This is a schematic diagram of a fixed resistor discharge structure for a supercapacitor system provided in an embodiment of the present invention;

[0079] Figure 2 This is a schematic diagram of a multi-stage resistive discharge structure of a supercapacitor system provided in an embodiment of the present invention;

[0080] Figure 3 This is a schematic diagram of a discharge resistance evaluation method provided in an embodiment of the present invention;

[0081] Figure 4 This is a schematic diagram of the equivalent circuit of a single supercapacitor cell provided in an embodiment of the present invention;

[0082] Figure 5 A schematic diagram of the discharge circuit of a single supercapacitor cell provided in an embodiment of the present invention;

[0083] Figure 6 This is a schematic diagram of the discharge process of a single supercapacitor cell provided in an embodiment of the present invention;

[0084] Figure 7 This is a schematic diagram of the charging and discharging process of a single supercapacitor cell provided in an embodiment of the present invention;

[0085] Figure 8 This is a schematic diagram of the charging process of a single supercapacitor cell provided in an embodiment of the present invention;

[0086] Figure 9 This is a schematic flowchart of a branch parameter determination method for a discharge resistance evaluation method provided in an embodiment of the present invention;

[0087] Figure 10 A schematic diagram of the discharge process of a single supercapacitor cell provided in an embodiment of the present invention;

[0088] Figure 11 This is a schematic flowchart of a method for determining a first target time according to an embodiment of the present invention;

[0089] Figure 12 This is a schematic diagram of another discharge resistance evaluation method provided in an embodiment of the present invention;

[0090] Figure 13 A schematic diagram of curve fitting for a three-dimensional array provided by the present invention;

[0091] Figure 14 A schematic diagram of the equivalent circuit of the supercapacitor system provided by the present invention;

[0092] Figure 15 A schematic diagram of the discharge circuit of the supercapacitor system provided by the present invention;

[0093] Figure 16 This is a schematic diagram of a discharge resistance evaluation device provided in an embodiment of the present invention;

[0094] Figure 17 This is a schematic diagram of an electronic device structure provided in an embodiment of the present invention. Detailed Implementation

[0095] 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.

[0096] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of the present invention.

[0097] Currently, supercapacitor systems generally employ two discharge methods. One method uses a fixed resistor for long-term discharge, extending the discharge time to achieve the desired discharge. Figure 1 As shown, Figure 1 The diagram illustrates the discharge of a fixed resistor. The equivalent electrical model of a supercapacitor system includes the equivalent series resistance (ESR) and capacitance C, using a fixed resistor R for long-term discharge. Another approach is to employ multi-stage resistor switching, such as... Figure 2 The equivalent circuit diagram shown uses a parallel equivalent resistor R to switch the resistance value. When the voltage is relatively high, a large resistor is used for discharge to prevent excessive discharge power; when the voltage is low, a small resistor is used to increase the discharge rate. This method can achieve short-term discharge, but it requires additional control units and more complex detection, control, and protection logic. It also requires more contactors and a larger design space, posing significant challenges to design and cost. Furthermore, after rapid discharge, the voltage rebound is faster, easily exceeding the safe voltage threshold, which poses a certain degree of danger.

[0098] To address the aforementioned technical problems, and to determine the discharge resistance based on the nonlinear characteristics and charge redistribution characteristics of supercapacitors in order to meet the needs of maintenance conditions with limited repair time, this application provides a discharge resistance evaluation method, as detailed in the embodiments below. Figure 3As shown, Figure 3 This is a schematic flowchart of a discharge resistance evaluation method provided by an embodiment of the present invention. The method includes the following steps:

[0099] Step 110: Obtain the target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage at the start of charging the target object with the rated current, the second voltage corresponding to the first preset charging time, the third voltage corresponding to the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the ratio of branch time constants.

[0100] Specifically, the target maintenance time is the time required to meet maintenance conditions, such as the specified or set maintenance time for routine maintenance or fault occurrence in urban railway systems. The maximum permissible maintenance time can be determined by considering multiple maintenance conditions, taking a value greater than the maximum maintenance time for all conditions. The rated capacitance of the target object can be the factory-set capacitance value. The fourth voltage generated after charging stops is the voltage to which the voltage of the target object momentarily drops when charging is complete. The discharge cutoff voltage is a manually set voltage value. The branch time constant ratio is the time relationship coefficient between the branches of the target object during charge distribution, which is related to the characteristics of the target object and can be determined based on its characteristics.

[0101] In an alternative example, the target object could be a single supercapacitor cell, or other objects that exhibit nonlinear characteristics and charge redistribution properties during charging and discharging.

[0102] The supercapacitor cells are charged with rated current, and the first voltage at the start of charging, the second voltage corresponding to the first preset charging time, the third voltage corresponding to the second preset charging time, and the fourth voltage generated after charging stops are obtained. Then, the target object is discharged, and the initial discharge time is obtained. The voltage at the initial discharge time is the fourth voltage.

[0103] For ease of explanation, the method of this invention will be described with the target object being a single supercapacitor cell. The five-branch equivalent electrical model of a single supercapacitor cell is as follows: Figure 4 As shown, U c R is the voltage across a single supercapacitor cell, measured by the supercapacitor management unit. conn R1 represents the equivalent connection resistance caused by the series and parallel connection of the supercapacitors. R1 is the resistance of the first branch, C1 is the first sub-capacitor of the first branch, R2 is the resistance of the second branch, C2 is the capacitor of the second branch, R3 is the resistance of the third branch, C3 is the capacitor of the third branch, R4 is the resistance of the fourth branch, C4 is the capacitor of the fourth branch, R5 is the resistance of the fifth branch, C5 is the capacitor of the fifth branch, and K... VLet K be the coefficient of the voltage-controlled capacitor, and let K be the capacitance value of the second sub-capacitor in the first branch. V and U c Relatedly, during the charging and discharging process of a single supercapacitor cell, because the terminal voltage U... c Since the capacitance value changes constantly, the capacitance value of the second sub-capacitor also changes with time, exhibiting time-varying characteristics. The capacitance value of the second sub-capacitor is calculated according to the following formula:

[0104] C0 = Kv * U c (Formula 1)

[0105] Where C0 is the capacitance value of the second sub-capacitor, K V U is the capacitance coefficient of the voltage-controlled capacitor, that is, the capacitance coefficient of the second sub-capacitor in the first branch. c This represents the terminal voltage of a single supercapacitor cell.

[0106] During discharge, an equivalent electrical model of a single supercapacitor cell is constructed, such as... Figure 5 As shown, the capacitance of the first branch is the sum of the first sub-capacitor and the second sub-capacitor, i.e., K. V *U c +C1, U1 is the voltage of the first branch, U2 is the voltage of the second branch, U3 is the voltage of the third branch, U4 is the voltage of the fourth branch, U5 is the voltage of the fifth branch, R cell This is the discharge resistor for a single supercapacitor cell.

[0107] During the maintenance period, the discharge curve throughout the entire maintenance process is as follows: Figure 6 As shown, the supercapacitor cells first pass through a constant-value discharge resistor R. cell Discharge, voltage U c From the initial voltage U B Start descending to U T1 After the first stage of resistive discharge ends, the system enters the second stage for charge redistribution, with voltage U... c Slowly rise and exceed U T2 No maintenance work is performed during the discharge process, but maintenance work can be performed during the charge redistribution process. T1 U is the discharge cutoff voltage. T2 For the agreed safe voltage, U T2 During manual maintenance, the voltage can be set to 36V, but the specific value should be determined based on the actual operating conditions. This is just an example. t0 is the start of discharge, t0 to t1 is the discharge time, and t0 to t2 is the maintenance time. When t0 is 0, the value of t1 is the discharge time, and the value of t2 is the maintenance time. Considering the inconsistency of capacitor values, to prevent some individual cells from reverse charging, the discharge cutoff voltage U... T1 It can be determined using the following formula:

[0108] U T1 =0.02*UB (Formula 2)

[0109] Step 120: Based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the ratio of branch time constants, determine the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch other than the first branch in the target object.

[0110] Specifically, the first branch is the first branch in the target object. Using the parameter information during the charging process of a single supercapacitor cell, the model parameters of the single supercapacitor cell are determined, including the first sub-capacitor of the first branch, the capacitance coefficient corresponding to the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance corresponding to each branch in the target object other than the first branch.

[0111] In an optional example, such as in Figure 7 The schematic diagram of the supercapacitor cell charging process shown illustrates that the supercapacitor cell is charged with a rated current I. N During charging, the voltage rises from 0V to the unit's rated voltage U. N This is the third voltage, followed by a resting period that should be greater than three times the maintenance time. U0 is the instantaneous terminal voltage of the supercapacitor cell during the initial charging stage, i.e., the first voltage. After charging is complete, the voltage drops to U0. D That is, the fourth voltage.

[0112] A schematic diagram of the voltage change in the first branch during the charging process is shown below. Figure 8 As shown, charging is completed to the first preset charging time t. B The voltage value U1 at 0.1s is the second voltage. The supercapacitor is charged to its rated voltage U. N The second preset charging time corresponding to this time is t. E .

[0113] Optionally, based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the branch time constant ratio, determine the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch in the target object other than the first branch. Specifically, this includes, for example: Figure 9 The steps shown are as follows:

[0114] Step 1201: Determine the resistance of the first branch based on the third voltage, the fourth voltage, and the rated current.

[0115] Specifically, Figure 5The first branch resistor shown can be passed through Figure 8 The parameters for the charging process shown are determined using the following formulas:

[0116]

[0117] Where R1 is the resistance of the first branch, U N For the third voltage, I N U is the rated current during charging. D This is the fourth voltage.

[0118] Step 1202: Determine the first sub-capacitor based on the rated current, the first preset charging time, the first voltage, and the second voltage.

[0119] Specifically, Figure 5 The first sub-capacitor C1 in the capacitor is determined by the following formula:

[0120]

[0121] Among them, t B The first preset charging time.

[0122] Step 1203: Determine the capacitance coefficient based on the first sub-capacitor, rated current, second preset charging time, and third voltage.

[0123] The capacitance coefficient K corresponding to the second sub-capacitor of the first branch is... V It can be determined using the following formula:

[0124]

[0125] Among them, t E The second preset charging time.

[0126] Once the capacitance coefficient is determined, the terminal voltage U can be determined using Formula 1. c The second sub-capacitor of the corresponding first branch is used to determine the capacitance of the first branch.

[0127] Step 1204: Determine the branch voltage corresponding to each branch in the target object based on the first branch resistance, the first sub-capacitor, the third voltage, and the ratio of branch time constants.

[0128] Specifically, the time constant of the first branch satisfies the following formula:

[0129] τ1=R1*(K v *U N +C1)(Formula Six)

[0130] Where τ1 is the time constant of the first branch.

[0131] Let the time constant of the second branch be τ2, the time constant of the third branch be τ3, the time constant of the fourth branch be τ4, and the time constant of the fifth branch be τ5. The ratio of the branch time constants among the branches satisfies the following formula:

[0132]

[0133] The erfcinv function is the inverse function of the complementary error function, and n takes any positive integer from 1 to 4.

[0134] The values ​​of τ2, τ3, τ4, and τ5 can be obtained from the above formulas. The terminal voltage of a single supercapacitor cell can be monitored in real time. Therefore, based on the time constant of each branch, the voltage corresponding to each branch after charging is completed can be determined. Figure 10 As shown, the initial voltage of the first branch is U. D The charge transfer from the first branch to the second branch ends after 3*τ1 time. Therefore, the voltage corresponding to the second branch is U. A1 The charge transfer in the first and second branches ends in the third branch after a time interval of 3*τ2. The charge transfer in the remaining branches is similar. Neglecting the charge transfer in non-adjacent branches, the voltage corresponding to the third branch is U. B1 The voltage corresponding to the fourth branch is U. C1 The voltage corresponding to the fifth branch is U. D1 .

[0135] Step 1205: Determine the capacitance of the i-th branch based on the branch voltage corresponding to the i-th branch, the capacitance, rated current, second preset charging time, first voltage, and capacitance coefficient of the first branch.

[0136] Specifically, in Figure 5 In the equivalent circuit diagram of a single supercapacitor shown, charge redistribution begins immediately after charging is complete, and charge transfer begins in the branches. The voltage change process is as follows: Figure 10 As shown, according to the principle of charge balance, when the transfer of charge from the first branch to the second branch ends, the following formula is satisfied:

[0137] I N *t E =(K V *U A1 +C1+C2)*(U A1 -U0)(Formula 8)

[0138] Where C2 is the capacitance of the second branch, which is an unknown quantity, while the other parameters are known quantities. Therefore, the value of C2 can be determined according to the above formula.

[0139] When the charge transfer from the first and second branches to the third branch ends, the following formula is satisfied:

[0140] I N *t E =(K V *U B1 +C1+C2+C3)*(U B1 -U0)(Formula Nine)

[0141] Where C3 is the capacitance of the third branch, which is an unknown quantity, while the other parameters are known quantities. Therefore, the value of C3 can be determined according to the above formula.

[0142] Similarly, when the charge transfer from the first, second, and third branches to the fourth branch ends, the following formula is satisfied:

[0143] I N *t E =(K V *U C1 +C1+C2+C3+C4)*(U C1 -U0)(Formula 10)

[0144] Where C4 is the capacitance of the fourth branch, which is an unknown quantity, while the other parameters are known quantities. Therefore, the value of C4 can be determined according to the above formula.

[0145] Similarly, when the charge transfer from the first, second, third, and fourth branches to the fifth branch ends, the following formula is satisfied:

[0146] I N *t E =(K V *U D1 +C1+C2+C3+C4+C5)*(U D1 -U0)(Formula Eleven)

[0147] C5 is the capacitance of the fifth branch, which is an unknown quantity, while the other parameters are known quantities. Therefore, the value of C5 can be determined according to the above formula.

[0148] Step 1206: Determine the resistance of the i-th branch based on the capacitance of the i-th branch and the time constant corresponding to the i-th branch.

[0149] Specifically, i is a positive integer greater than or equal to 2.

[0150] The time constant of the nth branch satisfies the following formula:

[0151] τ n =R n *C n (Formula 12)

[0152] Among them, R n Let n be the resistance of the nth branch. nLet be the capacitance of the nth branch.

[0153] Substituting C2, C3, C4, and C5 into Formula XII will determine R2, R3, R4, and R5.

[0154] In an optional example, after determining C1, C2, C3, C4, C5, R1, R2, R3, R4, and R5, the above parameters can be optimized using a non-dominated sorting genetic algorithm (NSGA-II). Taking the terminal voltage of the supercapacitor cell as the optimization target, the parameters are continuously adjusted and iterated to reduce the error between the calculated terminal voltage data and the test data to a certain range, and finally obtain more accurate parameter values ​​for the supercapacitor cell.

[0155] Step 130: Determine the resistance range of the discharge resistor for discharging the target object based on the maximum allowable maintenance time, rated capacitance, third voltage, and discharge cutoff voltage.

[0156] Specifically, in such Figure 6 The schematic diagram of the discharge process of a single supercapacitor cell shows that the discharge of a single supercapacitor cell reaches U... T2 Given time t2, and the rated capacitance of a single supercapacitor cell being C, then the resistance of the single supercapacitor cell is R. c It can be determined using the following formula:

[0157]

[0158] Among them, U T1 U is the discharge cutoff voltage. B This is the initial discharge voltage.

[0159] The maximum resistance value within the resistance range can be a value greater than R. c Larger values, for example, could be R c 1.2 times:

[0160] R max =1.2R c (Formula Fourteen)

[0161] Therefore, the range of values ​​for the discharge resistance of a single supercapacitor cell can be determined as follows:

[0162] 0 <R cell <R max (Formula Fifteen)

[0163] Among them, R cell This refers to the discharge resistance of a single supercapacitor cell.

[0164] Step 140: Iterate the discharge resistor within a preset unit resistance range to obtain the discharge resistor corresponding to each iteration cycle.

[0165] Specifically, the preset unit resistance value can be 0.01 ohms, 0.1 ohms, etc. The specific value can be set according to actual needs. For example, if the resistance range is large and the number of iterations is small, a larger unit resistance value can be selected.

[0166] In an optional example, for instance, R cell From 0 ohms to R max The system iterates through the data with a preset unit resistance of 0.01 ohms to form R. cell An array, containing each R cell This serves as the discharge resistor for each iteration cycle.

[0167] Step 150: Input the third voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitance and resistance corresponding to each branch in the target object except the first branch into the pre-constructed first state model and perform iterative processing from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time when the initial voltage is reached.

[0168] Specifically, the first discharge resistor is the discharge resistor within the current iteration cycle.

[0169] In one optional example, a single supercapacitor cell has a discharge state and a charge redistribution state during the discharge process. The two states can be analyzed separately to obtain the maintenance time corresponding to the first discharge resistance.

[0170] During the discharge process, a first-state model is constructed. Figure 5 In the equivalent discharge circuit diagram of the supercapacitor cell shown, it is assumed that it is charged to the rated voltage U. N Discharge begins. In the initial discharge state, the values ​​of U1 to U5 are equal and are the same as U. N Equivalent value, the capacitance of the first branch is the sum of the first sub-capacitor and the second sub-capacitor of the first branch:

[0171] C 1s =C0 + C1 (Formula Sixteen)

[0172] Among them, C 1s Let C1 be the capacitor of the first branch, C0 be the second sub-capacitor of the first branch, and C1 be the first sub-capacitor of the first branch. As shown in Formula 1, C0 is linearly related to the terminal voltage of the supercapacitor cell. Because the terminal voltage changes constantly during discharge, C0 also changes constantly with the terminal voltage. 1s It also changes with the terminal voltage at any given moment.

[0173] Optionally, the third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object (excluding the first branch) are input into a pre-constructed first state model for iterative processing from the initial discharge moment to obtain the initial voltage of the second state model and the initial iteration moment when the initial voltage is reached, including:

[0174] The third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except the first branch are input into the pre-constructed first state model and iterate from the initial discharge time to obtain the terminal voltage of the target object and the branch voltage of each branch at each time.

[0175] When the terminal voltage reaches the second preset condition, the current time is confirmed as the initial iteration time, and the branch voltage of the j-th branch is confirmed as the initial voltage, where the j-th branch is any one of the branches of the target object, and j is a positive integer.

[0176] Specifically, during the discharge process of a single supercapacitor cell, the first state model is the discharge state module of the single supercapacitor cell, and the circuit state equation is as follows:

[0177]

[0178] Wherein, U1(t) is the voltage of the first branch at time t, U2(t) is the voltage of the second branch at time t, U3(t) is the voltage of the third branch at time t, U4(t) is the voltage of the fourth branch at time t, and U5(t) is the voltage of the fifth branch at time t.

[0179] in,

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192]

[0193]

[0194]

[0195]

[0196]

[0197]

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205] Among them, A11 is The time-varying relationship coefficient between U1(t) and U1(t) is A12. The time-varying relationship coefficient between U2(t) and A13 is... The time-varying relationship coefficient between U3(t) and A14 is... The time-dependent coefficient of U4(t), A15 is... The time-dependent coefficient of U5(t), A21, is... The time-varying relationship coefficient between U1(t) and U1(t) is A22. The coefficient of relationship between U2(t) and time, A23 is The coefficient of relationship between U3(t) and time, A24 is The time-varying relationship coefficient between U4(t) and A25 is... The time-varying relationship coefficient between U5(t) and A31 is... The time-varying relationship coefficient between U1(t) and U1(t) is A32. The coefficient of relationship between U2(t) and time, A33, is The time-varying relationship coefficient between U3(t) and A34 is... The time-varying relationship coefficient between U4(t) and A35 is... The time-varying relationship coefficient between U5(t) and A41 is... The time-varying relationship coefficient between U1(t) and U1(t) is A42. The coefficient of relationship between U2(t) and time, A43 is The time-varying relationship coefficient between U3(t) and A44 is... The time-varying relationship coefficient between U4(t) and U4(t) is A45. The time-varying relationship coefficient between U5(t) and A51 is... The time-varying relationship coefficient between U1(t) and U1(t) is A52. The coefficient of relationship between U2(t) and time, A53 is The coefficient of relationship between U3(t) and time, A54 is The coefficient of relationship between U4(t) and time, A55 is The time-varying coefficient between U5(t) and U5(t).

[0206] In formulas (18) to (42),

[0207] M = R1 * R2 * R3 * R4 * R5 + R cell *R2*R3*R4*R5+R cell *R1*R3*R4*R5+

[0208] R cell *R1*R2*R4*R5+R cell *R1*R2*R3*R5+R cell *R1*R2*R3*R4

[0209] (Formula 43)

[0210] In formulas (18) to (43), R cell For the discharge resistance in the current iteration cycle, for example, R cell From 0 ohms to R max If the system iterates through the system using a preset unit resistance of 0.01 ohms, then in the first iteration, R... cellThe resistance is 0.01 ohms, and R is [value missing] in the second iteration. cell It is 0.02 ohms.

[0211] Let the state matrix be:

[0212]

[0213] The initial state of the state equations at t=0 satisfies:

[0214]

[0215] Where U1(0) to U5(0) represent the voltages of the first to fifth branches in the initial discharge state, respectively. In the initial discharge state, the voltage of each branch is equal to U... N Because C in state matrix A 1s With terminal voltage U C Linear dependence, U C The state changes over time during the discharge process, therefore the state matrix A is a time-varying state matrix. Given a fixed initial value, the iteration period of each discharge resistor can be solved numerically. The discharge state model is constructed as follows:

[0216]

[0217] Wherein, U1(t) is the voltage of the first branch at the current moment during the discharge phase, U1(t+1) is the voltage of the first branch at the next moment during the discharge phase, U2(t) is the voltage of the second branch at the current moment during the discharge phase, U2(t+1) is the voltage of the second branch at the next moment during the discharge phase, U3(t) is the voltage of the third branch at the current moment during the discharge phase, U3(t+1) is the voltage of the third branch at the next moment during the discharge phase, U4(t) is the voltage of the fourth branch at the current moment during the discharge phase, U4(t+1) is the voltage of the fourth branch at the next moment during the discharge phase, U5(t) is the voltage of the fifth branch at the current moment during the discharge phase, and U5(t+1) is the voltage of the fifth branch at the next moment during the discharge phase.

[0218] By using the voltage of any branch at the current moment, the voltage at the next moment, the branch capacitance, and the branch resistance of each branch, the terminal voltage of a single supercapacitor cell can be calculated (taking the first branch as an example):

[0219] U c (t+1)=U1(t)+R1*C 1s *(U1(t+1)-U1(t))(Formula 47)

[0220] This formula indicates that, using the current voltage of the first branch, the voltage of the first branch at the next moment, the capacitance of the first branch, and the resistance of the first branch, the terminal voltage of a single supercapacitor cell at the next moment, U, can be determined. c (t+1) represents the terminal voltage of a single supercapacitor cell.

[0221] When the second preset condition U is met c (t)=U T1 When the voltage at the current moment reaches the preset discharge cutoff voltage, the time at this moment is recorded as the initial iteration time of the second state model. The final voltage of any branch at the initial iteration time is the initial charge redistribution voltage of the second state model.

[0222] Step 160: Input the initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitor and resistor corresponding to each branch of the target object except the first branch into the pre-constructed second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches the first preset condition, confirm that the time from the initial discharge time to the time when the first preset condition is reached is the first target time corresponding to the first discharge resistor.

[0223] Specifically, the second state model is a charge redistribution state model. The initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitance and resistance corresponding to each branch of the target object except the first branch are input into the charge redistribution state model for iterative processing to obtain the terminal voltage of the supercapacitor cell at each moment. When the terminal voltage of the supercapacitor cell reaches the first preset condition, the time from the initial discharge moment to the moment when the first preset condition is reached is determined as the first target time corresponding to the first discharge resistor. The first target time is the agreed maintenance time.

[0224] Optionally, the initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch of the target object (excluding the first branch) are input into a pre-constructed second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches a first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is determined as the first target time corresponding to the first discharge resistor, including, for example... Figure 11 The method steps shown are as follows:

[0225] Step 1110: Construct a charge redistribution state matrix based on the first discharge resistor, capacitance coefficient, first sub-capacitor, first branch resistance, and the capacitance and resistance of each branch in the target object except the first branch.

[0226] Specifically, during the charge redistribution stage, the resistor has completed its discharge process, and the voltage of a single supercapacitor cell slowly increases due to charge redistribution. The state equation for this stage is:

[0227]

[0228] The charge redistribution state matrix B is:

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242]

[0243]

[0244]

[0245]

[0246]

[0247]

[0248]

[0249]

[0250]

[0251]

[0252]

[0253]

[0254]

[0255] Among them, B11 is The time-varying relationship coefficient between U1(t) and U1(t) is A12. The coefficient of relationship between U2(t) and time, B13 is The time-varying relationship coefficient between U3(t) and B14 is... The time-dependent coefficient of the relationship between U4(t) and B15 is... The time-varying relationship coefficient between U5(t) and B21 is... The time-varying relationship coefficient between U1(t) and B22 is... The coefficient of relationship between B23 and U2(t) over time is B23. The coefficient of relationship between B24 and U3(t) over time is... The time-varying relationship coefficient between B25 and U4(t) is... The time-varying relationship coefficient between U5(t) and B31 is... The time-varying relationship coefficient between U1(t) and B32 is... The coefficient of relationship between U2(t) and time, B33 is The time-varying relationship coefficient between B3(t) and U3(t) is B34. The time-varying relationship coefficient between B35 and U4(t) is... The time-varying relationship coefficient between U5(t) and B41 is... The time-varying relationship coefficient between U1(t) and U1(t) is B42. The coefficient of relationship between U2(t) and time, B43 is The coefficient of relationship between U3(t) and time, B44 is The time-dependent coefficient of the relationship between U4(t) and B45 is... The time-varying relationship coefficient between U5(t) and B51 is... The time-varying relationship coefficient between U1(t) and U1(t) is B52. The coefficient of relationship between U2(t) and time, B53 is The coefficient of relationship between U3(t) and time, B54 is The time-varying relationship coefficient between U4(t) and B55 is... The coefficient of relationship between U5(t) and time, M, is the same as that in (Formula 43).

[0256] Step 1120: Input the initial voltage of the second state and the charge redistribution state matrix into the second state model and perform iterative processing from the initial iteration time to obtain the branch voltage corresponding to each branch at each time in the charge redistribution state.

[0257] Specifically, the initial state of the charge redistribution equation is:

[0258]

[0259] Where t1 is the initial iteration time of the second state, i.e. the charge redistribution state, and U1(t1) is the initial voltage of the second state. This formula means that at the initial iteration time, the voltage of each branch is the same and is the branch voltage of any branch at the end of the discharge, i.e. the initial iteration time.

[0260] In an optional example, the initial voltage of the second state can be replaced by the voltage of any of the other branches at the initial discharge moment.

[0261] Step 1130: Determine the terminal voltage of the target object at each moment based on the branch voltage, branch capacitance, and branch resistance of the kth branch at each moment.

[0262] Specifically, the k-th branch is any one of the branches of the target object. Because C in the state matrix B... 1s With terminal voltage U C Linear correlation, while U C The charge redistribution process changes with time, therefore the state matrix B is a time-varying state matrix. Given a fixed initial value, the iteration period of each discharge resistor can be solved numerically. The charge redistribution state model is constructed as follows:

[0263]

[0264] Wherein, U1(t) is the voltage of the first branch at the current moment in the charge redistribution stage, U1(t+1) is the voltage of the first branch at the next moment in the charge redistribution stage, U2(t) is the voltage of the second branch at the current moment in the charge redistribution stage, U2(t+1) is the voltage of the second branch at the next moment in the charge redistribution stage, U3(t) is the voltage of the third branch at the current moment in the charge redistribution stage, U3(t+1) is the voltage of the third branch at the next moment in the charge redistribution stage, U4(t) is the voltage of the fourth branch at the current moment in the charge redistribution stage, U4(t+1) is the voltage of the fourth branch at the next moment in the charge redistribution stage, U5(t) is the voltage of the fifth branch at the current moment in the charge redistribution stage, and U5(t+1) is the voltage of the fifth branch at the next moment in the charge redistribution stage.

[0265] During the charge redistribution phase, the terminal voltage of a single supercapacitor cell can be calculated using the voltage of any branch at the current moment, the voltage at the next moment, the branch capacitance, and the branch resistance (taking the first branch as an example):

[0266] U c (t+1)=U1(t)+R1*C 1s *(U1(t+1)-U1(t))(Formula Seventy-Seven)

[0267] This formula indicates that, using the current voltage of the first branch, the voltage of the first branch at the next moment, the capacitance of the first branch, and the resistance of the first branch, the terminal voltage of a single supercapacitor cell at the next moment, U, can be determined. c (t+1) represents the terminal voltage of a single supercapacitor cell.

[0268] Step 1140: When the terminal voltage reaches the first preset condition, confirm that the time from the start of the initial discharge time to the time when the first preset condition is reached is the first target time corresponding to the first discharge resistor.

[0269] Specifically, the first preset constraint is the condition at the end of the charge redistribution. Because the voltage rises slowly during the charge redistribution process, maintenance must be stopped when the voltage reaches a certain safety threshold. Therefore, when the first preset condition is reached, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor, i.e., the maintenance time.

[0270] In an optional example, such as in Figure 6 In the schematic diagram of the discharge process of a single supercapacitor cell shown, the first preset condition is assumed to be U. T2 U T2 The specific value can be set according to the maintenance conditions. For example, in maintenance conditions involving manual intervention, U T2 It can be set to 36V.

[0271] Therefore, when U c (t)=U T2 When the first preset condition is met, record the corresponding time t2. Then, the time from the initial discharge time to t2 is the resistance R within this iteration cycle. cell The first target time for discharge and charge redistribution is the total maintenance time.

[0272] Step 170: Evaluate the resistance value of the target discharge resistor of the target object based on the target maintenance time, each discharge resistor, and the first target time corresponding to each discharge resistor.

[0273] Specifically, by obtaining the resistance value of each discharge resistor within the iteration cycle, the first target time corresponding to each discharge resistor can be determined. Based on this, the correspondence between the discharge resistor and the first target time can be obtained. Then, by giving the target maintenance time and the correspondence between the discharge resistor and the first target time, the discharge resistor corresponding to the target maintenance time can be determined.

[0274] In a preferred embodiment, the resistance value of the target discharge resistor of the target object is evaluated based on the target maintenance time, each discharge resistor, and the first target time corresponding to each discharge resistor, including:

[0275] By performing curve fitting on each discharge resistor and its corresponding first target time, a maintenance time model is obtained.

[0276] Based on the target maintenance time and the maintenance time model, the discharge resistance of the target object is estimated to obtain the target discharge resistance of the target object.

[0277] Specifically, the discharge resistance in each iteration cycle can determine the first target time, i.e. the maintenance time, corresponding to the discharge resistance in that iteration cycle. By taking the maintenance times corresponding to multiple discharge resistances and performing curve fitting, the maintenance time model can be obtained.

[0278] In an optional example, such as a fifth-order polynomial fit, the curve fitting equation for maintenance time versus discharge resistance would be:

[0279] z = b1 * x 5 +b2*x 4 +b3*x 3 +b4*x 2 +b5*x+b6 (Formula Seventy-Eight)

[0280] Where the independent variable x is the maintenance time t2, and the dependent variable z is the discharge resistance R. cellb1 to b6 are coefficients. After fitting, the values ​​of b1 to b6 can be obtained, thereby determining the maintenance time model. Then, by giving the target maintenance time, i.e. the value of x, the discharge resistor value corresponding to x can be determined.

[0281] When there are fewer than 5 values ​​for the discharge resistor, a fourth or third order polynomial fitting can be performed. Of course, the more values ​​are fitted, the more accurate the model will be.

[0282] During the discharge process, the moment when the discharge cutoff voltage is reached can also be recorded to determine the discharge end time of the discharge resistor, providing better data support for maintenance conditions.

[0283] Optionally, the method also includes, for example, Figure 12 The method steps shown are as follows:

[0284] Step 1210: When the terminal voltage reaches the second preset condition, confirm that the time between the initial discharge time and the time when the second preset condition is reached is the second target time corresponding to the first discharge resistor.

[0285] Specifically, the second preset condition is that the terminal voltage of the supercapacitor cell reaches the discharge cutoff voltage. The time when the second preset condition is reached in each iteration cycle is recorded. The time from the initial discharge time to the time when the second preset condition is reached is the second target time corresponding to the discharge resistance in that iteration cycle. The second target time is the discharge time corresponding to the resistance in each iteration cycle.

[0286] In this way, multiple three-dimensional arrays can be formed. Each array includes the discharge resistor within an iteration cycle and the corresponding first target time and second target time. Thus, there is a correspondence between the discharge resistor and the first target time, the discharge resistor and the second target time, and the first target time and the second target time.

[0287] Step 1220: Perform curve fitting on each first target time and its corresponding second target time to obtain the discharge time model.

[0288] Specifically, in an optional example, such as in Figure 6 In the schematic diagram of the discharge process of a single supercapacitor cell shown, a fifth-order polynomial fit is performed on each discharge resistor and its corresponding discharge time, as follows:

[0289] y = a1 * x 5 +a2*x 4 +a3*x 3 +a4*x 2 +a5*x+a6 (Formula 79)

[0290] In this model, the dependent variable y is the discharge time t1, the independent variable x is the maintenance time t2, and a1 to a6 are coefficients. After fitting, the values ​​of a1 to a6 can be obtained, thereby determining the discharge time model. Then, by giving the target maintenance time, i.e. the value of x, the discharge time corresponding to x can be determined. Based on the discharge time, the corresponding maintenance plan can be specified, such as determining the maintenance intervention time.

[0291] Of course, the discharge resistance in the three-dimensional array can also be curve-fitted with the second target time to obtain the correspondence between the discharge resistance and the second target time.

[0292] Step 1230: Estimate the first target time of the target object based on the target maintenance time and discharge time model, so as to evaluate the start time of maintenance of the target object based on the first target time.

[0293] Specifically, in an optional example, such as in Figure 6 The schematic diagram of the discharge process of a single supercapacitor cell shown is illustrated in the following diagram: [Diagram showing curve fitting of the three-dimensional array]. Figure 13 As shown, the vertical axis R cell R is the discharge resistance of a single supercapacitor cell. cell The relationship between E and discharge time t1 is shown by curve E,R cell The relationship between the curve and the maintenance time t2 is curve F,t 2max R is the maximum permissible maintenance time set according to operating conditions. max The discharge resistor is the one corresponding to the maximum allowable maintenance time.

[0294] In practical applications, supercapacitor cells generally appear in series-parallel connection systems, i.e., supercapacitor systems. There is a definite mapping relationship between supercapacitor systems and supercapacitor cells. First, the discharge resistance of the supercapacitor cells can be obtained by a given target maintenance time. Then, based on the connection form of the supercapacitor cells in the supercapacitor system, the discharge resistance of the supercapacitor system can be determined, making this method applicable to a wider range of scenarios.

[0295] Optionally, the method also includes:

[0296] Obtain the number of parallel and series connections of the target objects in the target object system;

[0297] The system discharge resistance of the supercapacitor system is determined based on the target discharge resistance, the number of parallel connections, and the number of series connections.

[0298] Specifically, when the target object is a single supercapacitor cell, the target system is a supercapacitor system, for example in... Figure 3 In the equivalent circuit diagram of a single supercapacitor shown, based on the individual unit's electrical model, the equivalent electrical model of an n-series, m-parallel supercapacitor system can be derived, as follows: Figure 14 As shown, U s The open-circuit voltage of the supercapacitor system is n*R. conn / m is the equivalent connection resistance of the supercapacitor system, U 1S U is the voltage of the first branch of the supercapacitor system. 2S U is the voltage of the second branch of the supercapacitor system. 3S U is the voltage of the third branch of the supercapacitor system. 4S U is the voltage of the fourth branch of the supercapacitor system. 5S n*R1 / m is the voltage of the fifth branch of the supercapacitor system, n*R2 / m is the resistance of the first branch of the supercapacitor system, n*R3 / m is the resistance of the third branch of the supercapacitor system, n*R4 / m is the resistance of the fourth branch of the supercapacitor system, n*R5 / m is the resistance of the fifth branch of the supercapacitor system, and m*(k v *(Us-I*R conn *n / m) / n+C1) / n is the first branch capacitor of the supercapacitor system, m*C2 / n is the second branch capacitor of the supercapacitor system, m*C3 / n is the third branch capacitor of the supercapacitor system, m*C4 / n is the fourth branch capacitor of the supercapacitor system, and m*C5 / n is the fifth branch capacitor of the supercapacitor system.

[0299] During resistive discharge, the influence of the connection resistance is negligible due to the small current. An equivalent electrical model of the supercapacitor system's discharge circuit can be established as follows: Figure 15 As shown, R d R is the discharge resistor of the supercapacitor system. d The discharge resistance R of a single supercapacitor cell cell The following relationship exists between them:

[0300]

[0301] Where n is the number of supercapacitor cells in series in the supercapacitor system, and m is the number of supercapacitor cells in parallel in the supercapacitor system. That is, n supercapacitor cells are first connected in series, and m sets of lines with n supercapacitor cells in series are then connected in parallel to obtain the supercapacitor system.

[0302] Supercapacitor systems share the same discharge and charge redistribution characteristics. During maintenance, the supercapacitor system first passes through a constant resistor R. dDuring discharge, the voltage Us decreases from the initial voltage to the discharge cutoff voltage. After the resistance discharge is complete, the system undergoes charge redistribution, and the voltage Us slowly rises and exceeds the set safety voltage, i.e., the first preset condition. No maintenance work is performed during the discharge process, but maintenance work can be performed during the charge redistribution process. In maintenance conditions, a total maintenance time t2 is generally given. Based on the correspondence between t2 and the discharge resistance of the supercapacitor cell, i.e., (Formula 78), the discharge resistance R of the supercapacitor cell can be determined. cell Then, the discharge resistance R of the supercapacitor system can be determined using the following formula. d :

[0303]

[0304] Where z is the target maintenance time, n is the number of supercapacitor cells in series in the supercapacitor system, and m is the number of supercapacitor cells in parallel in the supercapacitor system.

[0305] The discharge resistance evaluation method provided in this invention obtains the target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage at the start of charging the target object with the rated current, the second voltage corresponding to the charging time of the first preset charging time, the third voltage corresponding to the charging time of the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the branch time constant ratio. Based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the branch time constant ratio, the method determines the first sub-capacitor of the first branch in the target object, the capacitance coefficient corresponding to the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance corresponding to each branch in the target object other than the first branch, wherein the first branch is the first branch in the target object. Based on the maximum allowable maintenance time, the rated capacitance, the third voltage, and the discharge cutoff voltage, the method determines the resistance value range of the discharge resistor for discharging the target object. The method iterates the discharge resistor within the resistance value range according to a preset unit resistance value. The process involves obtaining the discharge resistance corresponding to each iteration cycle; inputting the third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch of the target object (excluding the first branch) into a pre-constructed first state model for iterative processing from the initial discharge time; obtaining the initial voltage of the second state model and the initial iteration time at which the initial voltage is reached; where the first discharge resistance is the discharge resistance within the current iteration cycle; inputting the initial voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch of the target object (excluding the first branch) into a pre-constructed second state model for iterative processing from the initial iteration time; when the terminal voltage of the target object reaches a first preset condition, confirming the time from the initial discharge time to the time when the first preset condition is reached as the first target time corresponding to the first discharge resistance; and evaluating the resistance value of the target discharge resistance of the target object based on the target maintenance time, each discharge resistance, and the first target time corresponding to each discharge resistance. First, the parameters of the nonlinear circuit model were set according to the charging process, which is more in line with the working conditions of nonlinear circuits. The discharge process and charge redistribution process of the nonlinear circuit model were solved by numerical iteration. The discharge resistance that meets both the safety of the working condition (first preset condition) and the target maintenance time can be quickly evaluated. It is applicable to any maintenance working condition, especially to short-term maintenance working conditions using supercapacitor energy storage system as energy recovery system, and has extremely high application value.

[0306] The above are embodiments of the discharge resistance evaluation method provided in this application. Other embodiments of the discharge resistance evaluation method provided in this application will be described below. Please refer to the following for details.

[0307] Figure 16 A discharge resistance evaluation device provided in an embodiment of the present invention includes: an acquisition module 1601, a processing module 1602, a determination module 1603, a first iteration module 1604, a second iteration module 1605, a third iteration module 1606, and an evaluation module 1607.

[0308] The acquisition module 1601 is used to acquire the target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage when charging the target object with the rated current begins, the second voltage corresponding to the first preset charging time, the third voltage corresponding to the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the branch time constant ratio.

[0309] The processing module 1602 is used to determine the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance coefficient of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch in the target object other than the first branch, based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the ratio of the branch time constants. The first branch is the first branch in the target object.

[0310] The determination module 1603 is used to determine the resistance range of the discharge resistor for discharging the target object based on the maximum allowable maintenance time, rated capacitance, third voltage, and discharge cutoff voltage.

[0311] The first iteration module 1604 is used to iterate the discharge resistor according to a preset unit resistance value within a resistance range to obtain the discharge resistor corresponding to each iteration cycle.

[0312] The second iteration module 1605 is used to input the third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except the first branch into the pre-constructed first state model for iterative processing from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time when the initial voltage is reached. The first discharge resistance is the discharge resistance in the current iteration cycle.

[0313] The third iteration module 1606 is used to input the initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitor and resistor corresponding to each branch in the target object except the first branch into the pre-constructed second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches the first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor.

[0314] The evaluation module 1607 is used to evaluate the resistance value of the target discharge resistor of the target object based on the target maintenance time, each discharge resistor, and the first target time corresponding to each discharge resistor.

[0315] Optionally, the device includes:

[0316] The determination module 1603 is specifically used to: determine the resistance of the first branch based on the third voltage, the fourth voltage, and the rated current; determine the first sub-capacitor based on the rated current, the first preset charging time, the first voltage, and the second voltage; determine the capacitance coefficient based on the first sub-capacitor, the rated current, the second preset charging time, and the third voltage; determine the branch voltage corresponding to each branch in the target object based on the ratio of the first branch resistance, the first sub-capacitor, the third voltage, and the branch time constant; determine the capacitance of the i-th branch based on the branch voltage corresponding to the i-th branch, the capacitance, rated current, second preset charging time, first voltage, and the capacitance coefficient of the branches preceding the i-th branch; and determine the resistance of the i-th branch based on the capacitance of the i-th branch and the time constant corresponding to the i-th branch, where i is a positive integer greater than or equal to 2.

[0317] Optionally, the device may also include: an input module 1608 and a determination module 1609;

[0318] The input module 1608 is used to input the third voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitance and resistance corresponding to each branch in the target object except the first branch into the pre-built first state model to iterate from the initial discharge time and obtain the terminal voltage of the target object and the branch voltage of each branch at each time.

[0319] The determination module 1609 is used to confirm that the current time is the initial iteration time when the terminal voltage reaches the second preset condition, and to confirm that the branch voltage of the j-th branch is the initial voltage, where the j-th branch is any one of the branches of the target object, and j is a positive integer.

[0320] Optionally, the device may also include: a construction module 1610 and a confirmation module 1611;

[0321] Module 1610 is used to construct a charge redistribution state matrix based on the first discharge resistor, capacitance coefficient, first sub-capacitor, first branch resistance, and the capacitance and resistance of each branch in the target object except the first branch.

[0322] The input module 1608 is also used to input the initial voltage of the second state and the charge redistribution state matrix into the second state model for iterative processing from the initial iteration time, and to obtain the branch voltage corresponding to each branch at each time in the charge redistribution state.

[0323] The determining module 1603 is also used to determine the terminal voltage of the target object at each time step based on the branch voltage, branch capacitance and branch resistance of the kth branch at each time step, wherein the kth branch is any one of the branches of the target object.

[0324] The confirmation module 1611 is also used to confirm, when the terminal voltage reaches the first preset condition, the time from the start of the initial discharge time to the time when the first preset condition is reached as the first target time corresponding to the first discharge resistor.

[0325] Optionally, the device may also include: a curve fitting module 1612;

[0326] The curve fitting module 1612 is used to perform curve fitting on each discharge resistor and its corresponding first target time to obtain the maintenance time model.

[0327] The processing module 1602 is also used to estimate the discharge resistance of the target object based on the target maintenance time and the maintenance time model, and to obtain the target discharge resistance of the target object.

[0328] Optionally, the device includes:

[0329] The confirmation module 1611 is also used to confirm that when the terminal voltage reaches the second preset condition, the time between the initial discharge time and the time when the second preset condition is reached is the second target time corresponding to the first discharge resistor.

[0330] The curve fitting module 1610 is also used to perform curve fitting on each first target time and the corresponding second target time to obtain the discharge time model.

[0331] The evaluation module 1607 is also used to estimate the first target time of the target object based on the target maintenance time and the discharge time model, so as to evaluate the start time of maintenance of the target object based on the first target time.

[0332] Optionally, the device includes:

[0333] The acquisition module 1601 is also used to acquire the number of parallel and series connections of the target objects in the target object system;

[0334] The determination module 1603 is also used to determine the system discharge resistance of the supercapacitor system based on the target discharge resistance, the number of parallel connections, and the number of series connections.

[0335] The functions performed by each component in the discharge resistance evaluation device provided in this embodiment have been described in detail in any of the above method embodiments, and therefore will not be repeated here.

[0336] This invention provides a discharge resistance evaluation device that acquires the target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage at the start of charging the target object with the rated current, the second voltage corresponding to the charging time of the first preset charging time, the third voltage corresponding to the charging time of the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the branch time constant ratio. Based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the branch time constant ratio, it determines the first sub-capacitor of the first branch in the target object, the capacitance coefficient corresponding to the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance corresponding to each branch in the target object other than the first branch, wherein the first branch is the first branch in the target object. Based on the maximum allowable maintenance time, the rated capacitance, the third voltage, and the discharge cutoff voltage, it determines the resistance range of the discharge resistor for discharging the target object. The discharge resistors are iterated within the resistance range according to a preset unit resistance value. The process involves obtaining the discharge resistance corresponding to each iteration cycle; inputting the third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch of the target object (excluding the first branch) into a pre-constructed first state model for iterative processing from the initial discharge time, and obtaining the initial voltage of the second state model and the initial iteration time when the initial voltage is reached. The first discharge resistance is the discharge resistance within the current iteration cycle. The process continues with inputting the initial voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch of the target object (excluding the first branch) into the pre-constructed second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches a first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is identified as the first target time corresponding to the first discharge resistance. Based on the target maintenance time, each discharge resistance, and the first target time corresponding to each discharge resistance, the resistance value of the target discharge resistance of the target object is evaluated. First, the parameters of the nonlinear circuit model were set according to the charging process, which is more in line with the working conditions of nonlinear circuits. The discharge process and charge redistribution process of the nonlinear circuit model were solved by numerical iteration. The discharge resistance that meets both the safety of the working condition (first preset condition) and the target maintenance time can be quickly evaluated. It is applicable to any maintenance working condition, especially to short-term maintenance working conditions using supercapacitor energy storage system as energy recovery system, and has extremely high application value.

[0337] like Figure 17As shown, this application provides an electronic device including a processor 111, a communication interface 112, a memory 113, and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114.

[0338] Memory 113 is used to store computer programs;

[0339] In one embodiment of this application, when the processor 111 executes the program stored in the memory 113, it implements the discharge resistance evaluation method provided in any of the foregoing method embodiments, including:

[0340] The target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage at the start of charging the target object with the rated current, the second voltage corresponding to the first preset charging time, the third voltage corresponding to the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the ratio of branch time constants are obtained.

[0341] Based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the ratio of the branch time constant, determine the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance coefficient of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch in the target object other than the first branch. The first branch is the first branch in the target object.

[0342] Based on the maximum allowable maintenance time, rated capacitance, third voltage, and discharge cutoff voltage, determine the resistance range of the discharge resistor for discharging the target object.

[0343] The discharge resistor is iterated within a preset unit resistance range to obtain the discharge resistor corresponding to each iteration cycle.

[0344] The third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except the first branch are input into the pre-constructed first state model and iterated from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time when the initial voltage is reached. The first discharge resistance is the discharge resistance in the current iteration cycle.

[0345] The initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistor, and the capacitance and resistance corresponding to each branch of the target object except the first branch are input into the pre-constructed second state model and iteratively processed from the initial iteration time. When the terminal voltage of the target object reaches the first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor.

[0346] The resistance value of the target discharge resistor of the target object is evaluated based on the target maintenance time, each discharge resistor, and the first target time corresponding to each discharge resistor.

[0347] Optionally, based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the branch time constant ratio, determine the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch other than the first branch in the target object, including:

[0348] The resistance of the first branch is determined based on the third voltage, the fourth voltage, and the rated current.

[0349] The first sub-capacitor is determined based on the rated current, the first preset charging time, the first voltage, and the second voltage;

[0350] The capacitance coefficient is determined based on the first sub-capacitor, the rated current, the second preset charging time, and the third voltage.

[0351] Based on the first branch resistance, the first sub-capacitor, the third voltage, and the ratio of branch time constants, determine the branch voltage corresponding to each branch in the target object;

[0352] The capacitance of the i-th branch is determined based on the branch voltage corresponding to the i-th branch, the capacitance, rated current, second preset charging time, first voltage, and capacitance coefficient of the first branch.

[0353] The resistance of the i-th branch is determined based on the capacitance of the i-th branch and the time constant corresponding to the i-th branch, where i is a positive integer greater than or equal to 2.

[0354] Optionally, the third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object (excluding the first branch) are input into a pre-constructed first state model for iterative processing from the initial discharge moment to obtain the initial voltage of the second state model and the initial iteration moment when the initial voltage is reached, including:

[0355] The third voltage, capacitance coefficient, first discharge resistance, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except the first branch are input into the pre-constructed first state model and iterate from the initial discharge time to obtain the terminal voltage of the target object and the branch voltage of each branch at each time.

[0356] When the terminal voltage reaches the second preset condition, the current time is confirmed as the initial iteration time, and the branch voltage of the j-th branch is confirmed as the initial voltage, where the j-th branch is any one of the branches of the target object, and j is a positive integer.

[0357] Optionally, the initial voltage, capacitance coefficient, first discharge resistor, first sub-capacitor, first branch resistance, and the capacitance and resistance corresponding to each branch of the target object (excluding the first branch) are input into a pre-constructed second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches a first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is determined to be the first target time corresponding to the first discharge resistor, including:

[0358] Based on the first discharge resistor, capacitance coefficient, first sub-capacitor, first branch resistance, and the capacitance and resistance of each branch in the target object except the first branch, construct the charge redistribution state matrix.

[0359] The initial voltage of the second state and the charge redistribution state matrix are input into the second state model and iterated from the initial iteration time to obtain the branch voltage corresponding to each branch at each time in the charge redistribution state.

[0360] Based on the branch voltage, branch capacitance, and branch resistance of the kth branch at each moment, determine the terminal voltage of the target object at each moment, where the kth branch is any one of the branches of the target object.

[0361] When the terminal voltage reaches the second preset condition, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor.

[0362] Optionally, the resistance value of the target discharge resistor of the target object is evaluated based on the target maintenance time, each discharge resistor, and the first target time corresponding to each discharge resistor, including:

[0363] By performing curve fitting on each discharge resistor and its corresponding first target time, a maintenance time model is obtained.

[0364] Based on the target maintenance time and the maintenance time model, the discharge resistance of the target object is estimated to obtain the target discharge resistance of the target object.

[0365] Optionally, the method also includes:

[0366] When the terminal voltage reaches the second preset condition, the time between the initial discharge time and the time when the second preset condition is reached is confirmed as the second target time corresponding to the first discharge resistor.

[0367] By performing curve fitting on each first target time and its corresponding second target time, a discharge time model is obtained.

[0368] The first target time for the target object is estimated based on the target maintenance time and discharge time model, so as to evaluate the start time of maintenance of the target object based on the first target time.

[0369] Optionally, the method also includes:

[0370] Obtain the number of parallel and series connections of the target objects in the target object system;

[0371] The system discharge resistance of the supercapacitor system is determined based on the target discharge resistance, the number of parallel connections, and the number of series connections.

[0372] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the discharge resistance evaluation method provided in any of the foregoing method embodiments.

[0373] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0374] The above are merely specific embodiments of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for evaluating discharge resistance, characterized in that, The method includes: The target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage at the start of charging the target object with the rated current, the second voltage corresponding to the first preset charging time, the third voltage corresponding to the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the branch time constant ratio are obtained. Based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the branch time constant ratio, determine the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance coefficient of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch in the target object other than the first branch, wherein the first branch is the first branch in the target object; Based on the maximum allowable maintenance time, the rated capacitance, the third voltage, and the discharge cutoff voltage, the resistance range of the discharge resistor for discharging the target object is determined. The discharge resistor is iterated within the resistance range according to a preset unit resistance value to obtain the discharge resistor corresponding to each iteration cycle. The third voltage, the capacitance coefficient, the first discharge resistor, the first sub-capacitor, the first branch resistor, and the capacitance and resistance corresponding to each branch in the target object except the first branch are input into the pre-constructed first state model and iteratively processed from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time when the initial voltage is reached, wherein the first discharge resistor is the discharge resistance in the current iteration cycle; The initial voltage, the capacitance coefficient, the first discharge resistor, the first sub-capacitor, the first branch resistor, and the capacitance and resistance corresponding to each branch of the target object except the first branch are input into the pre-constructed second state model and iteratively processed from the initial iteration time. When the terminal voltage of the target object reaches the first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is determined to be the first target time corresponding to the first discharge resistor. The resistance value of the target discharge resistor of the target object is evaluated based on the target maintenance time, each of the discharge resistors, and the first target time corresponding to each of the discharge resistors.

2. The method according to claim 1, characterized in that, The step of determining the capacitance coefficient of the first sub-capacitor of the first branch, the capacitance coefficient of the second sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch other than the first branch in the target object based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the branch time constant ratio, includes: The resistance of the first branch is determined based on the third voltage, the fourth voltage, and the rated current; The first sub-capacitor is determined based on the rated current, the first preset charging time, the first voltage, and the second voltage; The capacitance coefficient is determined based on the first sub-capacitor, the rated current, the second preset charging time, and the third voltage. Based on the first branch resistance, the first sub-capacitor, the third voltage, and the ratio of the branch time constants, determine the branch voltage corresponding to each branch in the target object; The capacitance of the i-th branch is determined based on the branch voltage corresponding to the i-th branch, the capacitances corresponding to the branches preceding the i-th branch, the rated current, the second preset charging time, the first voltage, and the capacitance coefficient of the first branch. The resistance of the i-th branch is determined based on the capacitance of the i-th branch and the time constant corresponding to the i-th branch, where i is a positive integer greater than or equal to 2.

3. The method according to claim 2, characterized in that, The step of inputting the third voltage, the capacitance coefficient, the first discharge resistor, the first sub-capacitor, the first branch resistance, and the capacitance and resistance corresponding to each branch in the target object (excluding the first branch) into a pre-constructed first state model for iterative processing from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time when the initial voltage is reached includes: The third voltage, the capacitance coefficient, the first discharge resistor, the first sub-capacitor, the first branch resistor, and the capacitance and resistance corresponding to each branch of the target object except the first branch are input into the pre-constructed first state model and iterate from the initial discharge time to obtain the terminal voltage of the target object and the branch voltage of each branch at each time. When the terminal voltage reaches the second preset condition, the current time is confirmed as the initial iteration time, and the branch voltage of the j-th branch is confirmed as the initial voltage, wherein the j-th branch is any one of the branches of the target object, and j is a positive integer.

4. The method according to any one of claims 1-3, characterized in that, The process involves inputting the initial voltage, the capacitance coefficient, the first discharge resistor, the first sub-capacitor, the first branch resistance, and the capacitance and resistance corresponding to each branch of the target object (excluding the first branch) into a pre-constructed second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches a first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is determined to be the first target time corresponding to the first discharge resistor, including: A charge redistribution state matrix is ​​constructed based on the first discharge resistor, the capacitance coefficient, the first sub-capacitor, the first branch resistance, and the capacitance and resistance corresponding to each branch in the target object except for the first branch. The initial voltage of the second state and the charge redistribution state matrix are input into the second state model and iterated from the initial iteration time to obtain the branch voltage corresponding to each branch at each time in the charge redistribution state. Based on the branch voltage, branch capacitance, and branch resistance of the kth branch at each moment, determine the terminal voltage of the target object corresponding to each moment, wherein the kth branch is any one of the branches of the target object. When the terminal voltage reaches the first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor.

5. The method according to claim 4, characterized in that, The step of evaluating the resistance value of the target discharge resistor of the target object based on the target maintenance time, each of the discharge resistors, and the first target time corresponding to each of the discharge resistors includes: By performing curve fitting on each of the discharge resistors and their corresponding first target time, a maintenance time model is obtained. The discharge resistance of the target object is estimated based on the target maintenance time and the maintenance time model to obtain the target discharge resistance of the target object.

6. The method according to any one of claims 1-3 or 5, characterized in that, The method further includes: When the terminal voltage reaches the second preset condition, the time from the initial discharge time to the time when the second preset condition is reached is confirmed as the second target time corresponding to the first discharge resistor. Curve fitting is performed on each of the first target times and the corresponding second target times to obtain the discharge time model; The first target time of the target object is estimated based on the target maintenance time and the discharge time model, so as to evaluate the start time of maintenance of the target object based on the first target time.

7. The method according to claim 6, characterized in that, The method further includes: Obtain the number of parallel and series connections of the target objects in the target object system; The system discharge resistance of the supercapacitor system is determined based on the target discharge resistance, the number of parallel connections, and the number of series connections.

8. A discharge resistance evaluation device, characterized in that, The device includes: The acquisition module is used to acquire the target maintenance time, the maximum allowable maintenance time, the rated capacitance of the target object, the first voltage when the target object is charged with the rated current, the second voltage corresponding to the first preset charging time, the third voltage corresponding to the second preset charging time, the fourth voltage generated after charging stops, the initial discharge time, the discharge cutoff voltage, and the branch time constant ratio. The processing module is used to determine, based on the rated current, the first preset charging time, the second preset charging time, the first voltage, the second voltage, the third voltage, the fourth voltage, and the branch time constant ratio, the capacitance coefficient of the first sub-capacitor of the first branch, the resistance of the first branch, and the capacitance and resistance of each branch in the target object other than the first branch, wherein the first branch is the first branch in the target object; The determination module is used to determine the resistance range of the discharge resistor for discharging the target object based on the maximum allowable maintenance time, the rated capacitance, the third voltage, and the discharge cutoff voltage. The first iteration module is used to iterate the discharge resistor according to a preset unit resistance value within the resistance range to obtain the discharge resistor corresponding to each iteration cycle. The second iteration module is used to input the third voltage, the capacitance coefficient, the first discharge resistor, the first sub-capacitor, the first branch resistor, and the capacitance and resistance corresponding to each branch in the target object except the first branch into the pre-constructed first state model for iterative processing from the initial discharge time to obtain the initial voltage of the second state model and the initial iteration time when the initial voltage is reached, wherein the first discharge resistor is the discharge resistance in the current iteration cycle; The third iteration module is used to input the initial voltage, the capacitance coefficient, the first discharge resistor, the first sub-capacitor, the first branch resistor, and the capacitance and resistance corresponding to each branch of the target object except the first branch into a pre-constructed second state model for iterative processing from the initial iteration time. When the terminal voltage of the target object reaches the first preset condition, the time from the initial discharge time to the time when the first preset condition is reached is confirmed as the first target time corresponding to the first discharge resistor. The evaluation module is used to evaluate the resistance value of the target discharge resistor of the target object based on the target maintenance time, each of the discharge resistors, and the first target time corresponding to each of the discharge resistors.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; The memory is used to store computer programs; When the processor executes the program stored in the memory, it implements the steps of the discharge resistance evaluation method according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the discharge resistance evaluation method as described in any one of claims 1-7.

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