A temperature control method for liquid-cooled supercharging pile

Abstract

The present invention provides a temperature control method for a liquid-cooled supercharging pile in the field of charging pile technology, comprising the following steps: step S10, creating a thermal resistance model; step S20, performing parameter tuning on the thermal resistance model to obtain thermal resistance parameters; step S30, the liquid-cooled supercharging pile obtains line internal resistance, output current and ambient temperature; step S40, the liquid-cooled supercharging pile calculates the fan opening, pump opening and theoretical gun head temperature based on the thermal resistance parameters, line internal resistance, output current and ambient temperature; step S50, the liquid-cooled supercharging pile starts charging based on the fan opening, pump opening and output current; step S60, during the charging process, the measured gun temperature of the charging gun is collected through a temperature sampling circuit, and the output current, fan opening and pump opening are dynamically adjusted based on the measured gun temperature, theoretical gun head temperature and the maximum steady-state temperature of the gun head. The advantages of the present invention are: greatly improving the flexibility and convenience of temperature control of the liquid-cooled supercharging pile, and greatly reducing power consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of charging piles, and in particular to a temperature control method for a liquid-cooled supercharging pile. Background Art

[0002] To increase charging speed, improve user experience, and reduce range anxiety, liquid-cooled supercharging stations have emerged. These stations primarily consist of a charging control module, a power module, a charging gun, a coolant pump, coolant, a cooling fan, and a temperature sampling circuit. The charging control module controls the power output of the power module, the coolant pump speed to regulate flow, and the cooling fan speed to adjust the cooling air volume. The temperature sampling circuit samples the temperatures of the air, the charging gun electrodes, and the coolant to achieve a closed-loop control system. The power module transmits power to the charging gun via a power cable. The coolant pump uses piping to achieve heat exchange between the coolant and the charging gun. The cooling fan dissipates the heat of the coolant into the air.

[0003] During operation, traditional liquid-cooled supercharging piles directly start the maximum cooling capacity and maximum circulation speed, or select several preset levels through control strategies to control the cooling capacity and circulation speed. This has the following disadvantages: 1. Excessive cooling capacity increases the power consumption of the liquid-cooled supercharging pile; 2. In order to verify whether the control strategy meets the requirements, it is necessary to continuously test the data corresponding to each point, which is very cumbersome.

[0004] Therefore, how to provide a temperature control method for a liquid-cooled supercharging pile to improve the flexibility and convenience of temperature control of the liquid-cooled supercharging pile and reduce power consumption has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a temperature control method for a liquid-cooled supercharging pile, so as to improve the flexibility and convenience of the temperature control of the liquid-cooled supercharging pile and reduce power consumption.

[0006] The present invention is implemented as follows: a temperature control method for a liquid-cooled supercharging pile, comprising the following steps:

[0007] Step S10: creating a thermal resistance model of a liquid-cooled supercharging pile;

[0008] Step S20, performing parameter tuning on the thermal resistance model to obtain thermal resistance parameters;

[0009] Step S30: The liquid-cooled supercharging pile obtains the line internal resistance, output current, and ambient temperature;

[0010] Step S40: The liquid-cooled supercharging pile calculates the fan opening, pump opening, and theoretical gun tip temperature based on the thermal resistance parameter, line internal resistance, output current, and ambient temperature.

[0011] Step S50: The liquid-cooled supercharging pile starts charging based on the fan opening, pump opening, and output current;

[0012] Step S60: During the charging process, the actual gun temperature of the charging gun is collected through the temperature sampling circuit, and the output current, fan opening and pump opening are dynamically adjusted based on the actual gun temperature, the theoretical gun head temperature and the maximum steady-state temperature of the gun head.

[0013] Furthermore, in step S10, the thermal resistance model includes a gun line static thermal resistance R t1 , a static thermal resistance R from coolant to air t2 , Dynamic thermal resistance R from coolant to charging gun t3 , Dynamic thermal resistance R from coolant to air t4 ;

[0014] R t2 With R t3 After parallel connection, one end is connected to R t1 One end is connected to R t4 One end of the connection; R t1 The other end of R t4 to the other end of the

[0015] Furthermore, in step S20, the thermal resistance parameter includes the static thermal resistance R t1 , static thermal resistance R from coolant to air t2 , dynamic thermal resistance R from coolant to charging gun t3 , dynamic thermal resistance R from coolant to air t4 resistance value.

[0016] Furthermore, the step S30 is specifically as follows:

[0017] The liquid-cooled supercharging pile parses the received charging instructions to obtain the output current, collects the ambient temperature through the temperature sampling circuit, obtains the line internal resistance by temperature compensating the rated internal resistance of the charging gun line, or obtains the line internal resistance by calculating the line voltage drop and current value.

[0018] Furthermore, in step S40, the calculation formula of the fan opening, pump opening and theoretical gun tip temperature is:

[0019]

[0020] Among them, R t5 =R t2 R t3 ; R t6 =R t4 +R t5 ; R t7 =R t1 R t6;K f Indicates the fan opening, the value range is [0,100]; R f Indicates the dynamic thermal resistance between coolant and air when the fan opening is 100%; K P Indicates the pump opening, the value range is [0,100]; R P It represents the dynamic thermal resistance between the coolant and the charging gun when the pump opening is 100°; i represents the output current; r represents the internal resistance of the charging gun circuit; T1 represents the theoretical gun tip temperature; and T3 represents the ambient temperature.

[0021] Furthermore, the step S50 is specifically as follows:

[0022] The liquid-cooled supercharging pile controls the cooling fan to operate based on the fan opening, controls the coolant pump to operate based on the pump opening, and controls the charging gun to operate based on the output current, thereby starting charging.

[0023] Furthermore, the step S60 is specifically as follows:

[0024] During the charging process, the liquid-cooled supercharging pile collects the actual temperature of the charging gun through the temperature sampling circuit;

[0025] When the measured gun temperature is higher than the theoretical gun head temperature, the fan opening and the pump opening are recalculated and adjusted;

[0026] When the measured gun temperature is higher than the maximum steady-state temperature of the gun head, the output current is gradually reduced until the measured gun temperature is lower than the maximum steady-state temperature of the gun head.

[0027] Furthermore, in step S60, the maximum steady-state temperature of the gun tip is calculated as follows:

[0028] The maximum steady-state temperature of the gun tip = the maximum limit temperature of the gun tip - safety margin.

[0029] The advantages of the present invention are:

[0030] By creating a thermal resistance model of the liquid-cooled supercharging pile and performing parameter tuning to obtain thermal resistance parameters, the liquid-cooled supercharging pile obtains the line internal resistance, output current and ambient temperature, and calculates the fan opening, pump opening and theoretical gun head temperature based on the thermal resistance parameters, line internal resistance, output current and ambient temperature, and starts charging based on the fan opening, pump opening and output current; during the charging process, the measured gun temperature (gun head temperature) of the charging gun is collected, and the output current, fan opening and pump opening are dynamically adjusted based on the measured gun temperature, theoretical gun head temperature and the maximum steady-state temperature of the gun head; that is, through the thermal resistance model, the thermal resistance parameters can be obtained at room temperature, avoiding a large number of high and low temperature experiments, saving a lot of time and test verification costs; and the fan opening and pump opening are dynamically adjusted during the temperature control process, that is, the cooling capacity and circulation speed are steplessly adjusted to avoid being at the maximum cooling capacity and maximum circulation speed all the time, ultimately greatly improving the flexibility and convenience of temperature control of the liquid-cooled supercharging pile and greatly reducing power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] Figure 1 This is a flow chart of a temperature control method for a liquid-cooled supercharging pile according to the present invention.

[0033] Figure 2 This is a circuit principle block diagram of the liquid-cooled supercharging pile of the present invention.

[0034] Figure 3 Schematic diagram of the thermal resistance model of the present invention. DETAILED DESCRIPTION

[0035] Please refer to Figures 1 to 3 As shown, a preferred embodiment of a temperature control method for a liquid-cooled supercharging pile of the present invention includes the following steps:

[0036] Step S10: creating a thermal resistance model of a liquid-cooled supercharging pile;

[0037] Step S20, performing parameter tuning on the thermal resistance model to obtain thermal resistance parameters;

[0038] Step S30: The liquid-cooled supercharging pile obtains the line internal resistance, output current, and ambient temperature;

[0039] Step S40: The liquid-cooled supercharging pile calculates the fan opening, pump opening, and theoretical gun tip temperature based on the thermal resistance parameter, line internal resistance, output current, and ambient temperature.

[0040] Step S50: The liquid-cooled supercharging pile starts charging based on the fan opening, pump opening, and output current;

[0041] Step S60: During the charging process, the actual gun temperature of the charging gun is collected through the temperature sampling circuit, and the output current, fan opening and pump opening are dynamically adjusted based on the actual gun temperature, the theoretical gun head temperature and the maximum steady-state temperature of the gun head.

[0042] In step S10, the thermal resistance model includes a gun line static thermal resistance R t1 , a static thermal resistance R from coolant to air t2 , Dynamic thermal resistance R from coolant to charging gun t3 , Dynamic thermal resistance R from coolant to air t4 ;

[0043] R t2 With R t3 After parallel connection, one end is connected to R t1 One end is connected to R t4 One end of the connection; R t1 The other end of R t4 to the other end of the

[0044] In step S20, the thermal resistance parameters include the static thermal resistance of the gun line R t1 , static thermal resistance R from coolant to air t2 , dynamic thermal resistance R from coolant to charging gun t3 , dynamic thermal resistance R from coolant to air t4 resistance value.

[0045] The parameter setting is specifically as follows:

[0046] Assume T1 is the theoretical gun tip temperature, T2 is the coolant temperature, T3 is the ambient temperature, R t1 is the static thermal resistance of the gun line, R t2 is the static thermal resistance from coolant to air, R t3 is the dynamic thermal resistance from the coolant to the charging gun, R t4 is the dynamic thermal resistance from coolant to air, R t3 Related to the pump opening, R t4 Related to the speed of the cooling fan.

[0047] The charging control module controls the speed of the cooling fan in proportion and defines the fan opening as K. f , 100% speed of the cooling fan under full opening condition corresponds to the fan opening of 100, so the fan opening K P The range is [0, 100]; similarly, the speed opening range of the coolant pump is [0, 100]; in specific implementation, the deviation between the opening control value and the actual value can be calibrated through tools such as a tachometer, and the software output value can be calibrated.

[0048] Assume that R t3 When the coolant pump opening is 100, it is RP , the coolant pump opening decreases, and the coolant flow rate per unit time decreases year-on-year. Therefore, in the interval Kp∈(0,100], R t3 =Rp / Kp; Similarly, assuming R t4 When the fan opening is 100, it is R f When the fan opening decreases, the fan speed decreases, and the air volume that can be brought out per unit time decreases year-on-year. Therefore, in the interval Kf∈(0,100], R t4 =Rf / Kf.

[0049] Therefore, the thermal resistance model needs to calculate R t1 、R t2 , Rp, and Rf. As long as 4 sets of different conditions are given, the values ​​of these 4 parameters can be calculated.

[0050] (1) Get R t1 :

[0051] When Kp=0,Kf=0,due to R t3 、R t4 Much larger than R t1 Can be ignored, then:

[0052]

[0053] (2) Obtain R t2 , Rp, Rf:

[0054] Assuming that the current flowing through the charging gun is i, the internal resistance of the charging line is r, the total heat generation power is p, the charging gun electrode temperature is T1, the coolant temperature is T2, and the ambient temperature is T3, under the conditions of Kp>0, Kf>0, we have:

[0055]

[0056] For the convenience of calculation, assume that Rt5, Rt6, and Rt7 satisfy the following formula:

[0057]

[0058] We can get:

[0059]

[0060] Under the condition of medium current change, three combinations are achieved by adjusting two groups of Kp and two groups of Kf, which are:

[0061] Combination a: (Kp1, Kf1), the test values ​​can be obtained: T1a, T2a, T3a, and R t3a =Rp / Kp1,R t4a =Rf / Kf1;

[0062] Combination b: (Kp1, Kf2), the coolant pump opening remains unchanged, adjust the fan opening, and the test values ​​are: T1b, T2b, T3b, and R t3b =Rp / Kp1=R t3a ,R t4b =Rf / Kf2, due to R t2 unchanged, so R t5a =R t5b ;

[0063] Combination c: (Kp2, Kf2), the fan opening remains unchanged, adjust the coolant pump opening, and the test values ​​are: T1c, T2c, T3c, and: R t3b =Rp / Kp2,R t4c =Rf / Kf2=R t4b , we can find:

[0064]

[0065] Combined with R t1 We can get:

[0066]

[0067] According to the above conditions, we can get:

[0068]

[0069] Substituting into the original formula we get:

[0070]

[0071] according to We can get:

[0072]

[0073] So far, R t1 、R t2 , Rp, and Rf have been obtained.

[0074] The step S30 is specifically as follows:

[0075] The liquid-cooled supercharging pile parses the received charging instructions to obtain the output current, collects the ambient temperature through the temperature sampling circuit, obtains the line internal resistance by temperature compensating the rated internal resistance of the charging gun line, or obtains the line internal resistance by calculating the line voltage drop and current value.

[0076] In step S40, the calculation formula of the fan opening, pump opening and theoretical gun tip temperature is:

[0077]

[0078] Among them, R t5 =R t2 R t3 ; R t6 =R t4 +R t5 ; R t7 =R t1 R t6 ;K f Indicates the fan opening, the value range is [0,100]; R f Indicates the dynamic thermal resistance between coolant and air when the fan opening is 100%; K P Indicates the pump opening, the value range is [0,100]; R P It represents the dynamic thermal resistance between the coolant and the charging gun when the pump opening is 100°; i represents the output current; r represents the internal resistance of the charging gun circuit; T1 represents the theoretical gun tip temperature; and T3 represents the ambient temperature.

[0079] The step S50 is specifically as follows:

[0080] The liquid-cooled supercharging pile controls the cooling fan to operate based on the fan opening, controls the coolant pump to operate based on the pump opening, and controls the charging gun to operate based on the output current, thereby starting charging.

[0081] The step S60 is specifically as follows:

[0082] During the charging process, the liquid-cooled supercharging pile collects the actual temperature of the charging gun through the temperature sampling circuit;

[0083] When the measured gun temperature is higher than the theoretical gun head temperature, the fan opening and the pump opening are recalculated and adjusted;

[0084] When the measured gun temperature is higher than the maximum steady-state temperature of the gun head, the output current is gradually reduced until the measured gun temperature is lower than the maximum steady-state temperature of the gun head.

[0085] During implementation, the following measures can be used to improve control:

[0086] ① If the actual gun temperature does not reach Y, the start command of the coolant pump and the cooling fan will not be issued temporarily. Wait until the actual gun temperature reaches Y before issuing it. The default setting is Y≤40℃;

[0087] ② At the current room temperature, when the coolant pump and cooling fan are set to the maximum opening, if the theoretical gun tip temperature is greater than the maximum steady-state temperature, the output current will be limited when starting charging so that the theoretical gun tip temperature calculated under this current condition is less than the maximum steady-state temperature;

[0088] ③ When the start-up command of the coolant pump and the cooling fan is issued, but the coolant pump or the cooling fan does not execute normally, the output current is limited, so that the calculated theoretical gun tip temperature is lower than the maximum steady-state temperature, and a fault is reported.

[0089] ④ When the coolant pump or cooling fan feedback is abnormal, the output current is limited so that the calculated theoretical gun tip temperature is lower than the maximum steady-state temperature and a fault is reported.

[0090] ⑤ When the gun wire temperature and the shell temperature of the charging gun reach the maximum temperature point, the output current is limited so that the calculated theoretical gun tip temperature is lower than the maximum steady-state temperature.

[0091] ⑥ When the coolant temperature reaches the maximum threshold of the coolant setting, the output current is limited so that the calculated theoretical gun tip temperature is lower than the maximum steady-state temperature.

[0092] In step S60, the calculation formula of the maximum steady-state temperature of the gun tip is:

[0093] The maximum steady-state temperature of the gun tip = the maximum limit temperature of the gun tip - safety margin.

[0094] In specific implementation, the optimal opening can be selected based on the following method:

[0095] Method 1: From the calculated data, select X opening degree data with the lowest power consumption based on the power consumption of the cooling fan and the coolant pump. X can be set to an integer between 10 and 20. Select E data with the highest maximum steady-state temperature from the gun tip. E can be set to an integer between 5 and 10. Then, select the intermediate steady-state temperature data, which is the optimal opening degree.

[0096] Method 2: Use a pre-calculated data table of the relationship between current, ambient temperature and opening to look up the table and find the optimal opening.

[0097] In summary, the advantages of the present invention are:

[0098] By creating a thermal resistance model of the liquid-cooled supercharging pile and performing parameter tuning to obtain thermal resistance parameters, the liquid-cooled supercharging pile obtains the line internal resistance, output current and ambient temperature, and calculates the fan opening, pump opening and theoretical gun head temperature based on the thermal resistance parameters, line internal resistance, output current and ambient temperature, and starts charging based on the fan opening, pump opening and output current; during the charging process, the measured gun temperature (gun head temperature) of the charging gun is collected, and the output current, fan opening and pump opening are dynamically adjusted based on the measured gun temperature, theoretical gun head temperature and the maximum steady-state temperature of the gun head; that is, through the thermal resistance model, the thermal resistance parameters can be obtained at room temperature, avoiding a large number of high and low temperature experiments, saving a lot of time and test verification costs; and the fan opening and pump opening are dynamically adjusted during the temperature control process, that is, the cooling capacity and circulation speed are steplessly adjusted to avoid being at the maximum cooling capacity and maximum circulation speed all the time, ultimately greatly improving the flexibility and convenience of temperature control of the liquid-cooled supercharging pile and greatly reducing power consumption.

[0099] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A temperature control method for a liquid-cooled supercharging pile, characterized by: The steps include: Step S10: Create a thermal resistance model of a liquid-cooled supercharging pile; the thermal resistance model includes a gun line static thermal resistance R t1 , a static thermal resistance R from coolant to air t2 , Dynamic thermal resistance R from coolant to charging gun t3 , Dynamic thermal resistance R from coolant to air t4 ; Step S20, performing parameter tuning on the thermal resistance model to obtain thermal resistance parameters; Step S30: The liquid-cooled supercharging pile obtains the line internal resistance, output current, and ambient temperature; Step S40: The liquid-cooled supercharging pile calculates the fan opening, pump opening, and theoretical gun tip temperature based on the thermal resistance parameter, line internal resistance, output current, and ambient temperature. The calculation formula for the fan opening, pump opening, and theoretical gun tip temperature is: ； in, ; ; ; Indicates the fan opening, the value range is [0,100]; Indicates the dynamic thermal resistance between coolant and air when the fan opening is 100%; Indicates the pump opening, the value range is [0,100]; Indicates the dynamic thermal resistance between the coolant and the charging gun when the pump opening is 100%; Indicates output current; Indicates the internal resistance of the charging gun circuit; Indicates the theoretical gun tip temperature; Indicates the ambient temperature; Step S50: The liquid-cooled supercharging pile starts charging based on the fan opening, pump opening, and output current; Step S60: During the charging process, the actual gun temperature of the charging gun is collected through the temperature sampling circuit, and the output current, fan opening and pump opening are dynamically adjusted based on the actual gun temperature, the theoretical gun head temperature and the maximum steady-state temperature of the gun head.

2. A temperature control method for a liquid-cooled supercharging pile according to claim 1, characterized in that: In step S10, R t2 With R t3 After parallel connection, one end is connected to R t1 One end is connected to R t4 One end of the connection; R t1 The other end of R t4 to the other end of the 3. The temperature control method for a liquid-cooled supercharging pile according to claim 1, characterized in that: In step S20, the thermal resistance parameters include the static thermal resistance of the gun line R t1 , static thermal resistance R from coolant to air t2 , dynamic thermal resistance R from coolant to charging gun t3 , dynamic thermal resistance R from coolant to air t4 resistance value.

4. The temperature control method for a liquid-cooled supercharging pile according to claim 1, characterized in that: The step S30 is specifically as follows: The liquid-cooled supercharging pile parses the received charging instructions to obtain the output current, collects the ambient temperature through the temperature sampling circuit, obtains the line internal resistance by temperature compensating the rated internal resistance of the charging gun line, or obtains the line internal resistance by calculating the line voltage drop and current value.

5. The temperature control method for a liquid-cooled supercharging pile according to claim 1, characterized in that: The step S50 is specifically as follows: The liquid-cooled supercharging pile controls the cooling fan to operate based on the fan opening, controls the coolant pump to operate based on the pump opening, and controls the charging gun to operate based on the output current, thereby starting charging.

6. The temperature control method for a liquid-cooled supercharging pile according to claim 1, characterized in that: The step S60 is specifically as follows: During the charging process, the liquid-cooled supercharging pile collects the actual temperature of the charging gun through the temperature sampling circuit; When the measured gun temperature is higher than the theoretical gun head temperature, the fan opening and the pump opening are recalculated and adjusted; When the measured gun temperature is higher than the maximum steady-state temperature of the gun head, the output current is gradually reduced until the measured gun temperature is lower than the maximum steady-state temperature of the gun head.

7. The temperature control method for a liquid-cooled supercharging pile according to claim 1, characterized in that: In step S60, the calculation formula of the maximum steady-state temperature of the gun tip is: The maximum steady-state temperature of the gun tip = the maximum limit temperature of the gun tip - safety margin.

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