A method for realizing time-sharing supercharging using supercapacitor

Abstract

The present invention discloses a method for realizing time-sharing supercharging by using a supercapacitor, which relates to the technical field of electric vehicle charging, including detecting the current power and charging demand of an electric vehicle battery, determining a target charging amount; dividing the charging process into N time periods based on the target charging amount; at the beginning of each time period, charging the supercapacitor to a first preset value by using a high-power charging device; disconnecting the circuit connection between the supercapacitor and the high-power charging device, and establishing a circuit connection between the supercapacitor and the electric vehicle battery; controlling the supercapacitor to transmit electric energy to the electric vehicle battery in a pulse manner, and dynamically adjusting the pulse frequency and duty cycle according to the real-time temperature and power information of the electric vehicle battery; and repeatedly executing the supercapacitor charging and discharging process until N time periods are completed or the battery is fully charged. The present invention shortens the battery charging time to a certain extent by using the supercapacitor as an energy cache unit and combining the segmented control strategy.

Description

Technical Field

[0001] The invention relates to the technical field of electric vehicle charging, and in particular to a method for realizing time-sharing supercharging by using a supercapacitor. Background Art

[0002] With the rapid development of new energy vehicles, electric vehicle charging technology faces many challenges. In the existing technology, directly using high-power chargers to charge electric vehicle batteries has the following problems: first, high-current direct charging can easily cause the battery temperature to rise sharply, affecting the battery life; second, the high-frequency pulse current during the charging process will cause impacts on the charging equipment and the power grid; third, the battery charge state and temperature changes cause charging efficiency fluctuations, making it difficult to achieve the optimal charging strategy.

[0003] Although there are charging solutions that use supercapacitors as buffers, there are still the following shortcomings: on the one hand, the charging parameters cannot be dynamically adjusted according to the battery status, and the charging efficiency is low; on the other hand, there is a lack of refined segmented control of the charging process, making it difficult to balance charging speed and safety; in addition, the charging and discharging control of supercapacitors in existing solutions is relatively simple, and its fast charging advantage cannot be fully utilized. Summary of the invention

[0004] In view of the problems existing in the existing electric vehicle charging solutions, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is how to utilize the fast charging characteristics of supercapacitors to achieve efficient and safe charging of electric vehicle batteries.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a method for time-sharing supercharging using a supercapacitor, which includes detecting the current power and charging demand of an electric vehicle battery to determine a target charge amount; based on the target charge amount, dividing the charging process into N time periods; at the beginning of each time period, charging the supercapacitor to a first preset value using a high-power charging device; disconnecting the circuit connection between the supercapacitor and the high-power charging device, and establishing a circuit connection between the supercapacitor and the electric vehicle battery; controlling the supercapacitor to transmit electrical energy to the electric vehicle battery in a pulse manner, and dynamically adjusting the pulse frequency and duty cycle according to the real-time temperature and power information of the electric vehicle battery; and repeating the supercapacitor charging and discharging process until N time periods are completed or the battery is fully charged.

[0008] As a preferred solution of the method for realizing time-sharing supercharging using a supercapacitor as described in the present invention, the charging process is divided into N time periods, including: calculating the overall charging time according to the corrected target charging amount; determining the optimal charging time of the electric vehicle battery according to the real-time temperature value; determining the number of initial time periods according to the overall charging time and the optimal charging time; calculating the initial duration of each time period according to the number of initial time periods and the overall charging time; dividing the N time periods into two charging stages based on the current state of charge value SOC of the electric vehicle battery, the charging stages including a fast charging stage and a slow charging stage; selecting a corresponding charging power curve according to different charging stages; and dynamically adjusting the duration of each time period according to the selected charging power curve.

[0009] As a preferred solution of the method for realizing time-sharing supercharging by using a supercapacitor as described in the present invention, wherein: disconnecting the circuit connection between the supercapacitor and the high-power charging device includes: collecting the capacitor voltage value at both ends of the supercapacitor, and when the capacitor voltage value reaches a first preset value, controlling the first switch tube to be turned on; monitoring and evaluating the electrical parameters of the output end of the LC buffer circuit, and executing the disconnection operation of the high-power charging device when the preset conditions are met; establishing the circuit connection between the supercapacitor and the electric vehicle battery includes: controlling the third switch tube to be turned on, establishing the connection between the LC buffer circuit and the electric vehicle battery; collecting the path voltage value and the path current value in the power supply path between the third switch tube and the electric vehicle battery; calculating the impedance value of the power supply path according to the path voltage value and the path current value; judging whether the impedance value is within the preset impedance range, and if the impedance value is within the preset impedance range, entering the pulse charging mode; wherein the electrical parameters include the buffer output voltage value and the buffer output current value, and the preset conditions include that the change rate of the buffer output voltage value is less than the second preset value, and the change rate of the buffer output current value is less than the third preset value.

[0010] As a preferred solution of the method of using a supercapacitor to achieve time-sharing supercharging described in the present invention, the following steps are included: dynamically adjusting the pulse frequency and duty cycle according to the real-time temperature and power information of the electric vehicle battery: collecting the real-time temperature value and the current state of charge value of the electric vehicle battery; the charging control unit queries the pulse control lookup table according to the real-time temperature value and the current state of charge value to determine the initial pulse frequency and duty cycle; starting pulse charging, and the supercapacitor transmits electrical energy to the electric vehicle battery through the LC buffer circuit; during the pulse charging process, real-time monitoring of the first parameter set; based on the first parameter set, dynamically adjusting the initial pulse frequency and duty cycle; if the current state of charge value reaches the high threshold, reducing the pulse frequency and duty cycle, and entering the slow charging stage; when the supercapacitor voltage drops to the minimum operating voltage threshold or the current time period ends, stopping the pulse transmission of the current charging cycle and disconnecting the circuit.

[0011] As a preferred solution of the method of the present invention for realizing time-sharing supercharging using a supercapacitor, the first parameter set includes the supercapacitor voltage, the electric vehicle battery terminal voltage, the charging current and the electric vehicle battery temperature.

[0012] As a preferred solution of the method for realizing time-sharing supercharging by using a supercapacitor according to the present invention, the calculation formula of the target charging amount is as follows:

[0013] ;

[0014] in, is the preset target state of charge value, SOC is the current state of charge value, is the rated capacity of the battery, is the current charging efficiency coefficient.

[0015] As a preferred solution of the method for realizing time-sharing supercharging by using a supercapacitor according to the present invention, the calculation formula of the current state of charge value is as follows:

[0016] ;

[0017] Among them, SOC is the current state of charge value, V is the real-time voltage value, and I is the real-time current value. is the weight coefficient, , , They are the minimum operating voltage, maximum operating voltage, and average operating voltage of the battery, is the initial state of charge value, is the rated capacity of the battery, and dt is the sampling time interval.

[0018] In a second aspect, an embodiment of the present invention provides a system for implementing time-sharing supercharging using a supercapacitor, which includes a battery status detection module for detecting the current power level and charging demand of an electric vehicle battery and determining a target charging amount; a charging process planning module for dividing the charging process into N time periods based on the target charging amount; a supercapacitor charging module for charging the supercapacitor to a first preset value using a high-power charging device at the beginning of each time period; a circuit switching control module for disconnecting the circuit connection between the supercapacitor and the high-power charging device and establishing a circuit connection between the supercapacitor and the electric vehicle battery; a pulse charging control module for controlling the supercapacitor to transmit electrical energy to the electric vehicle battery in a pulse manner and dynamically adjusting the pulse frequency and duty cycle according to the real-time temperature and power level information of the electric vehicle battery; and a charging cycle execution module for repeatedly executing the supercapacitor charging and discharging process until N time periods are completed or the battery is fully charged.

[0019] The beneficial effects of the present invention are as follows: the present invention shortens the battery charging time to a certain extent by using supercapacitors as energy cache units and combining them with a segmented control strategy. In particular, the application of the LC buffer circuit helps to reduce voltage fluctuations in traditional direct charging schemes. At the same time, the pulse charging control method based on impedance monitoring designed by the present invention improves the charging efficiency while ensuring charging safety through dynamic adjustment of pulse parameters. In addition, the triple switch tube coordinated control and protection mechanism adopted by the present invention can better control the temperature changes during the charging process and improve the charging uniformity, which has a positive effect on protecting the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings to be used in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 The present invention is a flow chart of a method for realizing time-sharing supercharging using a supercapacitor.

[0022] Figure 2 The basic topology of the charging system using supercapacitors to achieve time-sharing supercharging.

[0023] Figure 3 The present invention is a flow chart of duration calculation for a method of realizing time-sharing supercharging using supercapacitors. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0027] Example 1, reference Figure 1~Figure 3, which is the first embodiment of the present invention, and provides a method for realizing time-sharing supercharging using a supercapacitor,

[0028] It should be noted in advance that Figure 2 As shown, the charging system of this embodiment is mainly composed of a high-power charging device, a supercapacitor module, an LC buffer circuit and a switch control circuit. Among them, the high-power charging device is used to quickly charge the supercapacitor; the supercapacitor module is used as an energy cache unit to store the electric energy provided by the high-power charging device; the LC buffer circuit is composed of an inductor L and a capacitor C, which is used to smooth the fluctuations of voltage and current and reduce electromagnetic interference.

[0029] The switch control circuit includes three main switch tubes: the first switch tube controls the connection between the supercapacitor and the LC buffer circuit; the second switch tube controls the connection between the high-power charging device and the supercapacitor; and the third switch tube controls the connection between the LC buffer circuit and the electric vehicle battery. All switch tubes use high-reliability power MOSFET or IGBT devices, with safety features such as overcurrent protection and overvoltage protection.

[0030] In addition, the basic topology of the charging system is as follows Figure 2 As shown: the high-power charging device is connected to the supercapacitor through the second switch tube, the supercapacitor is connected to the input end of the LC buffer circuit through the first switch tube, and the output end of the LC buffer circuit is connected to the electric vehicle battery through the third switch tube.

[0031] Based on the above hardware structure, the method flow chart of this embodiment is as follows: Figure 1 As shown, the following steps are included:

[0032] S1: Detect the current power and charging demand of the electric vehicle battery and determine the target charging amount.

[0033] Specifically, the battery management system establishes an electrical connection with the electric vehicle battery, collects the real-time voltage value V, real-time current value I and real-time temperature value T of the electric vehicle battery, filters the collected data and processes abnormal values; according to the real-time voltage value V and real-time current value I, the current state of charge value SOC of the electric vehicle battery is calculated, and the specific formula is as follows:

[0034] ;

[0035] Among them, SOC is the current state of charge value, V is the real-time voltage value, and I is the real-time current value. is the weight coefficient, , , They are the minimum operating voltage, maximum operating voltage, and average operating voltage of the battery, is the initial state of charge value, is the rated capacity of the battery, and dt is the sampling time interval.

[0036] Further, the target charge capacity is calculated The process is as follows: subtract the preset target state of charge value from the current state of charge value to obtain the state of charge difference; read the electric vehicle battery capacity parameter, multiply the electric vehicle battery capacity parameter by the state of charge difference to obtain the theoretical target charge amount; calculate the current charging efficiency coefficient based on the real-time temperature value T; use the current charging efficiency coefficient to correct the theoretical target charge amount to obtain the corrected target charge amount. The specific formula is as follows:

[0037] ;

[0038] in, is the preset target state of charge value, SOC is the current state of charge value, is the rated capacity of the battery, is the current charging efficiency coefficient, the specific formula is as follows:

[0039] ;

[0040] in, is the current charging efficiency coefficient, T is the real-time temperature value ( ), For the best working temperature, is the temperature deviation threshold ( ), , They are respectively the maximum and minimum operating temperatures allowed for electric vehicle batteries.

[0041] Furthermore, the corrected target charging amount is transmitted to the charging control unit for use in time period division and charging strategy formulation for the subsequent charging process.

[0042] S2: Based on target charge , the charging process is divided into N time periods.

[0043] Specifically, the following steps are included:

[0044] S2.1: According to the revised target charging capacity , calculate the total charging time .

[0045] Specific, overall charging time The calculation formula is as follows:

[0046] ;

[0047] in, For the total charging time, is the corrected target charge capacity, is the rated power of the charging system, is the average charging efficiency (usually 0.8~0.9).

[0048] S2.2: Determine the optimal charging time of the electric vehicle battery according to the real-time temperature value T.

[0049] Specifically, the corresponding optimal charging time is obtained by searching the temperature-optimal charging time relationship data table; if the real-time temperature value T has no exact correspondence in the search table, it is calculated by a linear interpolation method.

[0050] S2.3: Divide the total charging time by the optimal charging time, and round up to obtain the number of initial time periods N.

[0051] It should be noted that rounding up is to ensure that the charging process can cover the entire target charging amount to avoid insufficient charging, and N should be no less than 2.

[0052] S2.4: Calculate the initial duration of each time period according to the initial number of time periods N and the total charging duration.

[0053] Specifically, the calculation formula for the initial duration is as follows:

[0054] ;

[0055] in, For the initial duration of each time period, is the total charging time, and N is the number of initial time periods.

[0056] S2.5: Based on the current state of charge value SOC of the electric vehicle battery, the N time periods are divided into two charging stages.

[0057] Specifically, the charging stage includes a fast charging stage and a slow charging stage. The division process is as follows: According to the current state of charge value SOC of the battery, the proportion of the fast charging stage is calculated. The calculation formula is as follows:

[0058] ;

[0059] Among them, SOC is the current state of charge value.

[0060] Furthermore, the function makes it so that: when the SOC is less than 0.2, the proportion of the fast charging stage is 1; when the SOC is greater than or equal to 0.2 and less than 0.8, the proportion of the fast charging stage decreases linearly with the increase of the SOC; when the SOC is greater than or equal to 0.8, the proportion of the fast charging stage is 0%.

[0061] Furthermore, according to the calculated fast charging stage ratio, the number of time periods in the fast charging stage is determined, and a corresponding number of time periods are divided into the fast charging stage, and the remaining time periods are divided into the slow charging stage.

[0062] Preferably, in this way, a smooth transition of the charging strategy with changes in SOC is achieved, which not only ensures the fast charging demand at low SOC, but also avoids excessive fast charging at high SOC, which is beneficial to improving charging efficiency and protecting battery life.

[0063] S2.6: Select a corresponding charging power curve from a preset charging power curve library according to different charging stages.

[0064] In this embodiment, a constant current charging curve is selected in the fast charging stage, and a constant voltage charging curve is selected in the slow charging stage.

[0065] S2.7: Dynamically adjust the duration of each time period according to the selected charging power curve.

[0066] Specifically, the dynamic adjustment process is as follows: when each time period is initialized, the initial charging power of the time period is determined based on the selected charging power curve; during the execution of the time period, the actual charging amount is continuously monitored; at the end of each time period, the deviation between the actual charging amount and the theoretical expected charging amount is calculated. Based on this deviation, the duration of the subsequent time periods is adjusted accordingly: when the actual charging amount is lower than expected, the duration of the next time period is appropriately extended; when the actual charging amount exceeds expectations, the duration of the next time period is appropriately shortened. Repeat this dynamic adjustment process until all scheduled time periods are over. If the target charging amount is still not achieved after the end of the final time period, the duration of the last time period will continue to be extended until the target charging amount requirement is met.

[0067] In addition, the adjustment amplitude is proportional to the difference, but a maximum adjustment limit (such as ±10% of the original duration) is set to avoid excessive fluctuations. At the same time, the charging power of the next time period is fine-tuned according to the adjusted duration to maintain consistency with the charging power curve.

[0068] S2.8: Transmit the duration of the N time periods and the corresponding charging power values ​​to the charging control unit for controlling the subsequent charging process.

[0069] It should be noted that the duration calculation flow chart is as follows Figure 3 shown.

[0070] S3: At the beginning of each time period, the supercapacitor is charged to a first preset value using a high-power charging device.

[0071] Specifically, the first preset value refers to the target charging voltage value of the supercapacitor, which is determined in the following way: first, a 12% margin is added to the nominal voltage of the electric vehicle battery to compensate for the voltage drop loss in the subsequent charging process; then the voltage constraint is determined, that is, the upper voltage limit value shall not exceed 90% of the rated voltage of the supercapacitor; finally, the initial voltage value is limited within the above constraints to obtain the final first preset value.

[0072] Furthermore, the present invention adopts a constant power charging method to charge the supercapacitor. In the initial stage of charging, that is, when the supercapacitor capacity is between 0% and 50%, the maximum charging current is controlled not to exceed 1.5 times the rated current to achieve fast charging; when the capacity reaches 50% to 80%, the maximum charging current is limited to within 1.2 times the rated current to ensure charging efficiency while avoiding excessive charging stress; when the capacity exceeds 80%, a linear regulation strategy is adopted to gradually reduce the charging current to 0.5 times the rated current to protect the supercapacitor and extend its service life.

[0073] It should be noted that during the entire charging process, the system continuously monitors the temperature changes of the supercapacitor. Once the temperature exceeds the threshold of 85°C, the control unit immediately reduces the charging power to 50% of the rated power until the temperature drops to a safe range. This dynamic temperature management strategy not only ensures the safety of the charging process, but also effectively avoids the performance degradation of the supercapacitor due to overheating.

[0074] Preferably, the above segmented control strategy not only ensures the efficiency of the supercapacitor charging process, but also achieves effective protection of the supercapacitor. At the same time, the safety and reliability of the charging process are ensured through the cooperation of temperature monitoring and power regulation mechanism.

[0075] S4: disconnect the circuit connection between the supercapacitor and the high-power charging device, and establish the circuit connection between the supercapacitor and the battery of the electric vehicle.

[0076] Specifically, the following steps are included:

[0077] S4.1: Collecting the capacitor voltage value at both ends of the super capacitor, and when the capacitor voltage value reaches a first preset value, controlling the first switch tube to be turned on.

[0078] One end of the first switch tube is connected in series with the super capacitor, and the other end of the first switch tube is connected to the input end of the LC buffer circuit.

[0079] S4.2: Monitor and evaluate electrical parameters at the output end of the LC buffer circuit, determine system stability, and perform a disconnect operation of the high-power charging device when preset conditions are met.

[0080] Specifically, the buffer output voltage value and the buffer output current value at the output end of the LC buffer circuit are continuously collected; and the change rate of the buffer output voltage value and the buffer output current value is calculated. In this embodiment, the change rate is calculated using a sliding window method.

[0081] Furthermore, it is determined whether the system satisfies the condition that the rate of change of the buffer output voltage value is less than the second preset value, and the rate of change of the buffer output current value is less than the third preset value. If so, the disconnection operation of the high-power charging device is executed. The disconnection operation includes: controlling the high-power charging device to gradually reduce the output power, and the reduction rate does not exceed 10% of the rated power per second; when the output power of the high-power charging device drops to 10% or less of the rated power, controlling the second switch tube to disconnect, and cutting off the circuit connection between the high-power charging device and the supercapacitor.

[0082] In this embodiment, the second preset value, the third preset value and the predetermined duration T are dynamically adjusted according to the current charging stage and the battery characteristics. In the fast charging stage, the second preset value ranges from 0.3V to 0.7V per millisecond, the third preset value ranges from 0.5A to 1.5A per millisecond, and the predetermined duration T is not less than 100 milliseconds. In the slow charging stage, the above parameter values ​​should be appropriately reduced, and the specific values ​​are automatically calculated by the system according to the battery characteristics and charging requirements. The size k of the sliding window is usually selected to be 10 to 20 to balance the response speed and noise resistance.

[0083] S4.3: Control the third switch tube to be turned on to establish a connection between the LC buffer circuit and the battery of the electric vehicle.

[0084] Among them, the input end of the third switch tube is electrically connected to the output end of the LC buffer circuit, and the output end of the third switch tube is electrically connected to the battery of the electric vehicle.

[0085] S4.4: Collect the path voltage value and path current value in the power supply path between the third switch tube and the battery of the electric vehicle.

[0086] S4.5: Calculate the impedance value of the power supply path based on the path voltage value and the path current value.

[0087] Specifically, the impedance value is calculated as follows:

[0088] ;

[0089] Where Z is the impedance value of the power supply path, is the path voltage value, is the path current value.

[0090] S4.6: Determine whether the impedance value is within the preset impedance range. If the impedance value is within the preset impedance range, enter the pulse charging mode.

[0091] It should be noted that the upper limit of the preset impedance range is 120% of the nominal impedance value of the power supply path, and the lower limit of the preset impedance range is 80% of the nominal impedance value of the power supply path. This design is to ensure charging efficiency while promptly detecting possible abnormalities in the power supply path, such as poor contact or short circuit.

[0092] In addition, the parameters of the pulse charging mode are dynamically adjusted according to the charging stage (fast charging or slow charging) divided in S2. In the fast charging stage, pulses with higher frequency and duty cycle are used; while in the slow charging stage, pulses with lower frequency and duty cycle are used to optimize charging efficiency and protect the battery.

[0093] S5: Use pulse mode to control the supercapacitor to transmit electric energy to the electric vehicle battery, and dynamically adjust the pulse frequency and duty cycle according to the real-time temperature and power information of the electric vehicle battery.

[0094] Specifically, the following steps are included:

[0095] S5.1: Collect the real-time temperature value T and current state of charge value SOC of the electric vehicle battery, and transmit them to the charging control unit.

[0096] It should be noted that data collection should be carried out after the supercapacitor establishes a circuit connection with the electric vehicle battery through the third switch tube to ensure the real-time and accuracy of the data.

[0097] S5.2: The charging control unit queries the pulse control lookup table according to the real-time temperature value T and the current state of charge value SOC to determine the initial pulse frequency and duty cycle.

[0098] It should be noted that the pulse control lookup table is pre-set based on battery type, SOC, temperature and other parameters to optimize the pulse charging process. When the SOC is low, a higher pulse frequency and a larger duty cycle are selected; when the SOC is high, the pulse frequency and duty cycle are gradually reduced to ensure a smooth transition of the charging process.

[0099] S5.3: Start pulse charging, and the supercapacitor transmits electrical energy to the electric vehicle battery in an intermittent manner through the LC buffer circuit.

[0100] The LC snubber circuit is composed of an inductor L and a capacitor C, which is used to smooth the fluctuations of voltage and current and reduce the instantaneous impact on the battery during charging. The pulse period is determined by the pulse frequency, and the charging time is determined by the duty cycle.

[0101] S5.4: During the pulse charging process, monitor the first parameter set in real time.

[0102] The first parameter set includes supercapacitor voltage, electric vehicle battery terminal voltage, charging current and electric vehicle battery temperature.

[0103] S5.5: Based on the first parameter data, dynamically adjust the initial pulse frequency and duty cycle.

[0104] Specifically, the charging control unit first calculates the difference between the supercapacitor voltage and the battery terminal voltage of the electric vehicle. When the difference is less than the preset minimum voltage difference threshold, the control unit pauses the current charging cycle and triggers the recharging process of the supercapacitor. During the charging process, if it is detected that the charging current exceeds the preset maximum current threshold, the control unit will reduce the duty cycle accordingly to prevent excessive current from damaging the battery. At the same time, the system continuously monitors the battery temperature of the electric vehicle. Once the temperature exceeds the preset maximum temperature threshold, the control unit will simultaneously reduce the pulse frequency and duty cycle, and even suspend charging if necessary until the temperature drops to a safe range.

[0105] Preferably, through this multi-parameter real-time monitoring and dynamic adjustment mechanism, the system can maximize battery safety and optimize the charging process while ensuring charging efficiency.

[0106] S5.6: If the current state of charge value SOC reaches the high threshold, the pulse frequency and duty cycle are gradually reduced to enter the slow charging stage.

[0107] Specifically, the charging control unit continuously monitors the SOC value of the battery. Once it detects that the SOC exceeds SOC_high, the system starts to execute the charging mode conversion. During this process, the pulse frequency f and the duty cycle D will gradually decrease according to the predetermined curve. This gradual adjustment ensures a smooth transition of the charging process and avoids the negative impact that sudden current changes may have on the battery. The slow charging stage uses a lower pulse frequency and duty cycle. The main purpose is to accurately control the charging process, prevent overcharging, and protect the battery to the greatest extent and extend its service life.

[0108] S5.7: When the supercapacitor voltage drops to the minimum operating voltage threshold or the current time period ends, the pulse transmission of the current charging cycle is stopped and the circuit connection is disconnected.

[0109] Specifically, the charging control unit continuously monitors the supercapacitor voltage, the current time, and the current state of charge value SOC. Once any condition is detected, the control unit immediately sends a signal to stop pulse transmission. Subsequently, the system disconnects the third switch tube, the first switch tube, and the second switch tube in a predetermined order to ensure that the circuit connection is safely cut off.

[0110] S6: Repeat the supercapacitor charging and discharging process until N time periods are completed or the battery is fully charged.

[0111] After each charging cycle, the system first evaluates whether the termination condition of the overall charging process is met. If the condition is not met, it returns to step S3 and starts a new round of supercapacitor charging. In this process, the system dynamically adjusts the charging parameters based on the data of the previous cycle, such as adjusting the duration of each time period or modifying the initial frequency and duty cycle of pulse charging to optimize the subsequent charging efficiency.

[0112] In addition, the system monitors the battery temperature T in real time. If T exceeds the preset maximum safe temperature, the charging process will be suspended until the temperature drops to a safe range. When the termination condition is met, the system performs a final safety check, including confirming that all switch tubes are disconnected, and recording the overall data of the entire charging process, and then completely exits the charging mode.

[0113] Furthermore, the present embodiment also provides a system for implementing time-sharing supercharging using a supercapacitor, including a battery status detection module, which is used to detect the current power level and charging demand of the electric vehicle battery and determine the target charging amount; a charging process planning module, which is used to divide the charging process into N time periods based on the target charging amount; a supercapacitor charging module, which is used to charge the supercapacitor to a first preset value using a high-power charging device at the beginning of each time period; a circuit switching control module, which is used to disconnect the circuit connection between the supercapacitor and the high-power charging device, and establish a circuit connection between the supercapacitor and the electric vehicle battery; a pulse charging control module, which is used to control the supercapacitor to transmit electrical energy to the electric vehicle battery in a pulse manner, and dynamically adjust the pulse frequency and duty cycle according to the real-time temperature and power information of the electric vehicle battery; and a charging cycle execution module, which is used to repeatedly execute the supercapacitor charging and discharging process until N time periods are completed or the battery is fully charged.

[0114] In summary, the present invention shortens the battery charging time to a certain extent by using supercapacitors as energy cache units and combining them with a segmented control strategy. In particular, the application of the LC buffer circuit helps to reduce voltage fluctuations in traditional direct charging schemes. At the same time, the pulse charging control method based on impedance monitoring designed by the present invention improves the charging efficiency while ensuring charging safety through dynamic adjustment of pulse parameters. In addition, the triple switch tube collaborative control and protection mechanism adopted by the present invention can better control the temperature changes during the charging process and improve the charging uniformity, which has a positive effect on protecting the battery life.

[0115] Example 2, reference Figure 1~Figure 3 , which is the second embodiment of the present invention, and this embodiment provides a method for time-sharing supercharging using a supercapacitor. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0116] First, in the initial condition setting, the initial SOC of the battery is 25%, the ambient temperature is 28°C, and the target charging SOC is 80%. The charging process is divided into 12 time periods, of which the fast charging stage occupies 7 time periods and the slow charging stage occupies 5 time periods. The initial frequency of pulse charging is set to 800Hz, and the duty cycle is 70%. The charging threshold of the supercapacitor is set to 450V, and the minimum operating voltage is 150V. To ensure data reliability, each group of experiments was repeated 3 times, and the average value was taken as the final result.

[0117] Afterwards, during the experiment, the data acquisition system recorded key parameters with a sampling period of 2ms. When the battery SOC was in the range of 25%~40%, the charging current stabilized at around 180A, and the charging power reached 180kW. At this time, the battery temperature slowly rose from 28°C to 35°C. As the SOC increased to 40%~60%, the system automatically reduced the charging current to 140A, the charging power to 150kW, and the battery temperature continued to rise to 39°C. When the SOC reached 60%~80%, the charging current was further reduced to 90A, the charging power was reduced to 100kW, and the battery temperature finally stabilized at 42°C.

[0118] Then, the experimental results showed that the entire charging process took 45 minutes, and the average charging efficiency reached 89.5%. The cycle efficiency of the supercapacitor remained above 92%, and the temperature rose to 58°C without triggering the temperature protection mechanism. The battery terminal voltage ripple coefficient was controlled within 1.8%, and the charging curve was smooth without obvious oscillation. Through impedance monitoring, the impedance value of the power supply path was always kept within the range of ±15% of the nominal value, indicating that the system stability was good.

[0119] Finally, compared with the traditional direct charging method, the advantages of the present invention are shown in Table 1.

[0120] Table 1 Comparison of performance indicators of the present invention and traditional direct charging method

[0121]

[0122] In summary, the experimental data show that compared with the traditional direct charging method, the scheme of the present invention has achieved certain improvements in key indicators such as charging time, charging power, and charging efficiency. In particular, under the premise of ensuring battery safety, the charging time of 25%~80% is shortened by 22.4%, while the voltage ripple is reduced by 28.0%, and the charging process is more stable. These data show that the present invention has certain application value in the field of electric vehicle fast charging.

[0123] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for realizing time-sharing supercharging using a supercapacitor, characterized in that: include, Detect the current power and charging requirements of the electric vehicle battery and determine the target charging amount; Based on the target charging amount, dividing the charging process into N time periods; At the beginning of each time period, charging the supercapacitor to a first preset value using a high-power charging device; Disconnecting the circuit connection between the supercapacitor and the high-power charging device, and establishing the circuit connection between the supercapacitor and the battery of the electric vehicle; Controlling the supercapacitor to transmit electric energy to the electric vehicle battery in a pulse manner, and dynamically adjusting the pulse frequency and duty cycle according to the real-time temperature and power information of the electric vehicle battery; Repeat the supercapacitor charging and discharging process until N time periods are completed or the battery is fully charged; The dividing the charging process into N time periods includes: Calculate the total charging time based on the corrected target charging amount; Determine the optimal charging time for electric vehicle batteries based on real-time temperature values; Determining the number of initial time periods according to the overall charging duration and the optimal charging duration; Calculating an initial duration of each time period according to the number of initial time periods and the total charging duration; Based on the current state of charge value SOC of the electric vehicle battery, the N time periods are divided into two charging stages, wherein the charging stages include a fast charging stage and a slow charging stage; According to the current state of charge value SOC of the battery, the proportion of the fast charging stage is calculated. The calculation formula is as follows: ； Among them, SOC is the current state of charge value; When the SOC is less than 0.2, the fast charging stage ratio is 1; when the SOC is greater than or equal to 0.2 and less than 0.8, the fast charging stage ratio decreases linearly with the increase of SOC; when the SOC is greater than or equal to 0.8, the fast charging stage ratio is 0; Select the corresponding charging power curve according to different charging stages; Dynamically adjust the duration of each time period according to the selected charging power curve; The disconnecting the circuit connection between the super capacitor and the high-power charging device comprises: Collecting the capacitor voltage value at both ends of the super capacitor, and when the capacitor voltage value reaches a first preset value, controlling the first switch tube to turn on; Monitor and evaluate electrical parameters at the output of the LC snubber circuit and, when a preset condition is met, perform a disconnect operation of the high-power charging device; The establishing of the circuit connection between the supercapacitor and the electric vehicle battery comprises: Controlling the third switch tube to be turned on to establish a connection between the LC buffer circuit and the battery of the electric vehicle; Collecting a path voltage value and a path current value in a power supply path between the third switch tube and the electric vehicle battery; Calculating the impedance value of the power supply path according to the path voltage value and the path current value; Determining whether the impedance value is within a preset impedance range, and if the impedance value is within the preset impedance range, entering a pulse charging mode; The electrical parameters include a buffer output voltage value and a buffer output current value, and the preset conditions include that a change rate of the buffer output voltage value is less than a second preset value, and a change rate of the buffer output current value is less than a third preset value.

2. The method for realizing time-sharing supercharging using a supercapacitor as claimed in claim 1, characterized in that: The step of dynamically adjusting the pulse frequency and duty cycle according to the real-time temperature and power information of the electric vehicle battery comprises the following steps: Collect the real-time temperature value and current state of charge value of the electric vehicle battery; The charging control unit queries the pulse control lookup table according to the real-time temperature value and the current state of charge value to determine the initial pulse frequency and duty cycle; Start pulse charging, and the supercapacitor transfers power to the electric vehicle battery through the LC buffer circuit; During the pulse charging process, a first parameter set is monitored in real time; Based on the first parameter set, dynamically adjusting the initial pulse frequency and duty cycle; If the current state of charge value reaches the high threshold, the pulse frequency and duty cycle are reduced to enter the slow charging stage; When the supercapacitor voltage drops to the minimum operating voltage threshold or the current time period ends, the pulse transmission of the current charging cycle is stopped and the circuit connection is disconnected.

3. The method for realizing time-sharing supercharging using a supercapacitor as claimed in claim 2, characterized in that: The first parameter set includes supercapacitor voltage, electric vehicle battery terminal voltage, charging current and electric vehicle battery temperature.

4. The method for realizing time-sharing supercharging using a supercapacitor as claimed in claim 1, characterized in that: The target charge capacity is calculated as follows: ； in, is the preset target state of charge value, SOC is the current state of charge value, is the rated capacity of the battery, is the current charging efficiency coefficient.

5. The method for realizing time-sharing supercharging using a supercapacitor as claimed in claim 4, characterized in that: The calculation formula of the current state of charge value is as follows: ； Among them, SOC is the current state of charge value, V is the real-time voltage value, and I is the real-time current value. is the weight coefficient, , , They are the minimum operating voltage, maximum operating voltage, and average operating voltage of the battery, is the initial state of charge value, is the rated capacity of the battery, and dt is the sampling time interval.

6. A system for realizing time-sharing supercharging using a supercapacitor, based on the method for realizing time-sharing supercharging using a supercapacitor according to any one of claims 1 to 5, characterized in that: Also includes, The battery status detection module is used to detect the current power level and charging demand of the electric vehicle battery and determine the target charging amount; A charging process planning module, configured to divide the charging process into N time periods based on the target charging amount; A supercapacitor charging module, used to charge the supercapacitor to a first preset value using a high-power charging device at the beginning of each time period; A circuit switching control module, used to disconnect the circuit connection between the supercapacitor and the high-power charging device, and establish a circuit connection between the supercapacitor and the electric vehicle battery; A pulse charging control module, used to control the supercapacitor to transmit electric energy to the electric vehicle battery in a pulse manner, and dynamically adjust the pulse frequency and duty cycle according to the real-time temperature and power information of the electric vehicle battery; The charging cycle execution module is used to repeatedly execute the supercapacitor charging and discharging process until N time periods are completed or the battery is fully charged.

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