Phase change cooling charging pile and temperature control method thereof

Abstract

The invention relates to the technical field of charging cooling, in particular to a phase change cooling charging pile and a temperature control method thereof. The phase change cooling charging pile comprises a control module, a phase change bin, a power module, a charging cable, a cable liquid cooling module and a heat exchange liquid cooling module, the power module is arranged at the bottom of the phase change bin, the phase change bin is filled with phase change liquid for immersing the power module, the cable liquid cooling module is used for transferring heat generated by the charging cable into the phase change liquid, and the heat exchange liquid cooling module is used for transferring the heat generated by the charging cable into the phase change liquid. The heat exchange liquid cooling module is used for condensing the phase change liquid gasified after heat absorption. When the charging pile works, the control module obtains the temperature of the charging cable and the temperature of the power module and regulates and controls the working power of the cable liquid cooling module, the heat exchange liquid cooling module and the power module in real time according to the temperature, so that it is ensured that the charging cable and the power module can be at the proper working temperature, the proportion of converting electric energy into internal energy is reduced, and the charging efficiency is improved. And the balance of heat production and heat dissipation efficiency is maintained, so that the charging efficiency can be ensured, and the increase of heat dissipation energy consumption caused by overhigh temperature can be avoided.

Description

Technical Field

[0001] The present invention relates to the field of charging cooling technology, and more specifically, to a phase change cooling charging pile and a temperature control method thereof. Background Art

[0002] With the development of new energy technologies, new energy vehicles (hereinafter referred to as electric vehicles) are placing increasingly higher demands on charging speeds. Improving charging speeds depends on two key factors: battery improvements and the availability of supporting charging station infrastructure to convert mains electricity into high-voltage direct current (HVDC). The conversion and transmission of current generates significant heat, which can cause charging stations to overheat and even catch fire and become damaged. Therefore, effective temperature control of charging stations is crucial to the development of new energy vehicles. Charging stations typically convert mains electricity into HVDC using power modules, which are then transmitted to the vehicle's battery via charging cables.

[0003] Copper is generally used as the conductor in charging cables. Metal conductors have the characteristic of increasing resistance as temperature rises. For example, for every 1°C increase in copper temperature, the resistivity will increase by 0.004 times its original value. As the resistivity increases, the proportion of electrical energy converted into internal energy will further increase, and the charging cable temperature will further increase, thereby increasing the load on the heat dissipation module and increasing power loss.

[0004] The power module also has an optimal operating temperature range, which is determined by a combination of charging efficiency and power module temperature. According to current research, for every 10°C increase in the power module temperature of a Supercharger charging station, charging efficiency decreases by 1.5%-2%, while for every 10°C decrease in the power module temperature of a Supercharger charging station, the condensing module power increases by 100-300W. The optimal operating temperature range for the power module is generally 50-70°C.

[0005] A Chinese patent discloses an integrated cooling system and method for a soaking super charging pile, aiming to solve the problem that the existing low-power charging pile air cooling and liquid cooling heat dissipation methods cannot meet the heat dissipation needs of super charging piles, and charging cables and charging guns lack effective cooling. The invention includes: a working medium tank filled with liquid phase change cooling working medium, which immerses the charging power module and leaves a gap at the top; a system pressure sensor is arranged to monitor the pressure, and a power sensor is arranged to obtain the power on the grid side; a charging power module temperature and state sensor is arranged on the charging power module; a condenser is sealingly connected to the top of the working medium tank; the end of the charging cable is connected to the working medium tank through a flange; a charging management module collects data and calculates the appropriate rotating speed of the air cooler or the appropriate flow rate of the condensing water. However, the cooling method of this scheme only considers the regulation of the heat dissipation components, and cannot adaptively adjust the heat generating components such as the power module and the charging cable, which may cause these components to continuously operate at high temperatures, increasing the proportion of electrical energy converted into internal energy, reducing charging efficiency, increasing heat dissipation energy consumption, and even causing the heat generation efficiency to be greater than the heat dissipation efficiency, posing a risk of high temperature out of control. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art temperature control, which cannot balance the heat dissipation energy consumption and charging efficiency, and provides a phase change cooling charging pile and a temperature control method thereof, which can dynamically control the charging power and the heat dissipation power in combination with the charging process to control the charging pile to always be in a suitable temperature range for charging.

[0007] To solve the above technical problems, the technical scheme adopted by the present application is: A phase change cooling charging pile is provided, comprising a cabinet, a phase change bin is arranged in the cabinet; a power module, the power module is arranged at the bottom of the phase change bin; a charging cable, the charging cable is arranged beside the cabinet, and the charging cable is electrically connected to the power module; a cable liquid cooling module, part of the cable liquid cooling module is arranged in the charging cable, and the rest of the cable liquid cooling module is arranged at the bottom of the phase change bin; a heat exchange liquid cooling module, part of the heat exchange liquid cooling module is arranged at the top of the phase change bin, and the rest of the heat exchange liquid cooling module is located outside the cabinet; a control module, the control module comprises a controller, a first temperature sensor and a second temperature sensor, the first temperature sensor is arranged in the charging cable, the controller is electrically connected to the power module, the cable liquid cooling module, the heat exchange liquid cooling module, the first temperature sensor and the second temperature sensor, and the controller can also be electrically connected to the charging vehicle; The phase change tank is also filled with phase change liquid, the liquid level of the phase change liquid is higher than the power module and the cable liquid cooling module, and the liquid level of the phase change liquid is lower than the heat exchange liquid cooling module.

[0008] Through this setting mode, when the electric vehicle is charging, the power module converts the mains into high-voltage direct current and delivers it to the electric vehicle battery through the charging cable. At this time, the power module and the charging cable both generate heat. The power module is immersed in the phase change liquid, and the generated heat is directly absorbed by the phase change liquid. The heat generated in the charging cable is delivered to the phase change tank by the cable liquid cooling module and transferred to the phase change liquid. The phase change liquid changes into phase change gas after absorbing heat, and the gasification takes away the heat. The phase change gas rises and meets the heat exchange liquid cooling module at the top of the phase change tank, transfers the heat to the heat exchange liquid cooling module, and condenses into phase change liquid and falls back to the bottom of the phase change tank. The heat exchange liquid cooling module exchanges heat to the cabinet outside. Due to the characteristics of the phase change liquid, the power module immersed in the phase change liquid is always in an environment not higher than the phase change temperature, and the heat exchange efficiency is guaranteed throughout the process. On the other hand, the design of the phase change tank provides redundancy for heat dissipation. When fast charging is needed, the power module is in a high heat generation state, the vaporization speed in the phase change tank is greater than the liquefaction speed, the phase change liquid decreases and the phase change gas increases in the phase change tank, but the phase change liquid can still remain below the phase change temperature, and the power module will not overheat. When the charging is completed and the standby state is reached, the power module is in a low power consumption or shutdown state. At this time, the liquefaction speed is greater than the vaporization speed, the phase change liquid increases and the phase change gas decreases, and it returns to the balance state until the next charging.

[0009] During the charging process, the control module can collect the state of the vehicle, including the battery model, the battery power percentage, etc. It can also collect the temperatures t1 and t2 in the power module and the charging cable in real time as reference information, and dynamically adjust the power of the cable liquid cooling module, the power module and the heat exchange liquid cooling module according to the above reference information, to balance the charging efficiency and temperature control, which can not only guarantee the charging efficiency, but also avoid the increase of heat dissipation energy consumption caused by high temperature.

[0010] Preferably, the phase change liquid uses an insulating phase change electronic fluorinated liquid.

[0011] Preferably, the cable liquid cooling module and the heat exchange liquid cooling module are provided with water cooling liquid, which includes but is not limited to ethylene glycol, mineral oil or single-phase fluorinated liquid.

[0012] A temperature control method of a phase change cooling charging pile is applied to the phase change cooling charging pile as described above, which comprises: S1, setting the first temperature valve T1, the second temperature valve T2, the third temperature valve T3 and the fourth temperature valve T4 by the control module; S2, electrically connecting the power module with the electric car through the charging cable, and the power module works; S3, the first temperature sensor acquires the first temperature value t1 at the charging cable and transmits it to the controller, and the second temperature sensor acquires the second temperature value t2 and transmits it to the controller; S4, the controller controls the operation of the cable liquid cooling module according to the comparison result of the first temperature value t1 and the first temperature threshold T1 and the second temperature threshold T2, and controls the operation of the heat exchange liquid cooling module and the power module according to the comparison result of the second temperature value t2 and the third temperature threshold T3 and the fourth temperature threshold T4; S5, after receiving the charging end instruction, the controller controls the power module to stop working, and controls the cable liquid cooling module and the heat exchange liquid cooling module to continue working; when t1

[0013] Through this setting mode, the user can preset the optimal working temperature interval according to the charging pile model. When the charging pile charges the electric car, the controller dynamically adjusts the working efficiency of the power module to control the heat generation of the power module and the charging cable; at the same time, the controller controls the working of the cable liquid cooling module and the working of the heat exchange liquid cooling module according to the heat generation of the power module and the charging cable, so as to ensure that the charging pile reaches the balance between heat generation and heat dissipation, and each component is controlled in the preset optimal working temperature interval, thereby inhibiting the rise of resistance in the charging cable and the power module, reducing the proportion of electric energy converted into internal energy, reducing the electric energy loss in the charging process, and reducing the heat dissipation burden of the cable liquid cooling module and the heat exchange liquid cooling module, reducing the electric energy consumption of heat dissipation, thereby reducing the heat dissipation burden and energy consumption without reducing the charging efficiency too much.

[0014] Preferably, the cable liquid cooling module comprises a liquid cooling hose, a first water pump and a first heat exchange pipeline, the charging cable comprises an outer pipe and a plurality of inner cables, the liquid cooling hose is in close contact with the inner cables, the liquid cooling hose, the first water pump and the first heat exchange pipeline are in communication to form a loop and are filled with water cooling liquid, and the first heat exchange pipeline is arranged in the phase change bin below the liquid level of the phase change liquid; In S4, the control method of the cable liquid cooling module is specifically: When t1 When T1 ; When T2

[0015] The water coolant in the liquid cooling hose absorbs heat in the charging cable and flows to the first heat exchange pipeline immersed in the phase change liquid under the driving of the first water pump. The water coolant in the first heat exchange pipeline releases heat to the phase change liquid and then flows back into the liquid cooling hose. Therefore, as the flow rate of the water coolant increases, the temperature exchange efficiency between the charging cable and the phase change liquid also increases. Through this arrangement, [T1, T2] is the optimal working temperature range of the charging cable. When the temperature is lower than T1, the temperature has little effect on the working efficiency of the charging cable, and T1 is close to the temperature of the charging cable under normal conditions. When the temperature is lower than T1, active heat dissipation has little effect on the charging cable, so the first water pump does not need to work at this time. When the charging cable is in the temperature range [T1, T2], the controller dynamically adjusts the first water pump to increase the flow rate of the water coolant in the liquid cooling hose and the first heat exchange pipeline by increasing the power of the first water pump, so as to improve the heat exchange capacity of the water coolant and the heat dissipation effect of the cable liquid cooling module, so that the heat dissipation rate can be adjusted synchronously with the heat generation efficiency of the charging cable. However, during the actual charging process, the charging cable may still exceed the optimal working temperature range due to environmental factors, actual charging rate, etc. At this time, the first water pump operates at the maximum set power to maximize the heat dissipation capacity of the cable heat exchange module.

[0016] Preferably, the cable liquid cooling module further comprises a first flow rate meter, which is electrically connected to the controller.

[0017] Through this arrangement, the controller can obtain the flow rate of the water coolant in the cable liquid cooling module and thus adjust the first water pump in a closed loop.

[0018] Preferably, in step S4, ; wherein, ; I is the output current of the power module, R1 is the direct current resistance of the charging cable, is the dynamic adjustment power of the power module at time t, V b is the output voltage of the power module, is the density of the water coolant, is the cross-sectional area of the first heat exchange pipeline, is the specific heat capacity of the water coolant, is the heat exchange temperature difference of the water coolant.

[0019] Through this arrangement, the controller can calculate the heat generated by the charging cable according to the output power of the power module and adjust the heat dissipation capacity of the cable liquid cooling module in real time, so as to keep the heat generation and heat dissipation in the charging cable balanced and avoid rapid or excessive temperature rise. The flow rate of the water coolant is adjusted according to the temperature, which can avoid energy waste caused by the heat dissipation efficiency being much higher than the heat generation efficiency.

[0020] Preferably, the heat exchange liquid cooling module comprises a second heat exchange pipeline, a second water pump and a water tank, the second heat exchange pipeline forms a communication loop with the water tank through the second water pump, the second heat exchange pipeline is arranged in the phase change bin and located above the liquid level of the phase change liquid, and the water tank is arranged outside the cabinet body. In S4, the control method of the heat exchange liquid cooling module and the power module is specifically: When t2 ; When T3≤t2 , < ; the controller dynamically adjusts the power of the second water pump so that the water flow speed in the second heat exchange pipeline is ; When T4≤t2, the controller controls the power module to operate at the minimum design power, and the second water pump operates at the maximum design power.

[0021] When the phase change liquid absorbs heat, it will be gasified into phase change gas, and the liquefaction efficiency of the phase change gas depends on the heat dissipation efficiency of the second heat exchange pipeline. When the gasification efficiency of the phase change liquid is higher than the liquefaction efficiency of the phase change gas, the pressure in the phase change bin will be too high, which will cause an explosion risk. Or the phase change liquid level is lower than the cable liquid cooling module and the power module, which cannot absorb heat, resulting in high temperature and equipment damage.

[0022] Through this setting mode, the controller can dynamically adjust the working conditions of the power module and the heat exchange liquid cooling module according to the temperature of the power module to control the heat generation of the power module, avoid the temperature of the power module being too high, and control the power of the heat exchange liquid cooling module at the same time, so as to ensure that the phase change gas liquefaction and the phase change liquid gasification are balanced, and avoid the temperature in the phase change bin being too high.

[0023] Under normal circumstances, the power module in operation is in the temperature interval of [T3, T4], at this time, the heat exchange liquid cooling module dynamically adjusts the water flow speed according to the temperature of the power module, so that the heat exchange efficiency of the water cooling liquid in the second heat exchange pipeline is equivalent to the heat generation efficiency of the power module, and the gas-liquid conversion balance in the phase change bin is maintained. Since the power module generates heat when the charging cabinet is working, only the temperature of the power module can be considered as a control source. When the power module temperature exceeds T4, it indicates that the heat dissipation capacity of the phase change liquid cannot bear the heat production load of the power module at this time, the output of the power module is adjusted to the minimum design value at this time, the minimum design power can include standby or shutdown conditions, to minimize the heat production of the power module, and the second water pump works at the highest power to improve the heat dissipation efficiency of the heat exchange liquid cooling module, thereby improving the liquefaction efficiency of the phase change gas and maintaining the gas-liquid balance in the phase change bin.

[0024] Preferably, in step S4, the dynamic adjustment power of the power module is specifically: ; Wherein, P max is the maximum allowed charging power of the battery, k is the attenuation coefficient, and SOC is the percentage of the remaining capacity of the battery to the nominal capacity.

[0025] Through this setting mode, the output power of the power module is dynamically adjusted according to the battery capacity of the charged battery, which is beneficial to the battery health and will not cause excessive impact on the charging efficiency.

[0026] Preferably, the heat exchange liquid cooling module further comprises a second flow rate meter, and the second flow rate meter is electrically connected to the controller.

[0027] Preferably, in step S4, the dynamic adjustment flow rate of the second water pump is: ; Wherein, is the total heat production power of the super-charging charging pile phase change bin at t, is the density of the cooling water, is the cross-sectional area of the second heat exchange pipeline, is the specific heat capacity of the cooling water, is the heat exchange temperature difference of the cooling water.

[0028] Through this setting mode, the second water pump can adjust the flow rate in real time according to the heat production in the phase change bin, so that the heat dissipation efficiency and the heat production efficiency are leveled, and the gas-liquid conversion balance in the phase change bin is maintained.

[0029] Preferably, , ; Wherein, is the heat production power of the power module at t, I is the charging current, R2 is the direct current resistance of the power module, Pe is the optimal charging power at t, V b is the battery voltage of the electric vehicle, is the heat production power of the charging cable at t, is the total heat production power in the phase change room of the super-charging charging pile at t.

[0030] Preferably, the control module further includes a pressure sensor for obtaining a first pressure value p1, the pressure sensor being installed on the top of the phase change chamber and electrically connected to the controller. The controller is pre-set with a first pressure valve P1 and a second pressure valve P2. In this case, in S4, the control method of the heat exchange liquid cooling module and the power module is specifically as follows: When t2 <T3且p1<P1时,所述功率模组以最大充电功率 Work; When T3≤t2<T4, p1<P2; or P1≤p1<P2, t2<T4, the controller controls the output power of the power module to be dynamically adjusted to , < The controller controls the second water pump to operate so that the water flow rate in the second heat exchange pipe is ; When T4≤t2 or P2≤p1, the controller controls the power module to operate at the minimum design power, and the second water pump to operate at the maximum design power.

[0031] Through this setting, the controller can intuitively monitor the gas-liquid relationship in the phase change chamber through the pressure sensor, and incorporate the pressure feedback in the phase change chamber into the dynamic adjustment of the power module and the heat exchange liquid cooling module, thereby preventing the risk of leakage or even explosion caused by excessive pressure in the phase change chamber, thereby further improving the safety of the charging pile.

[0032] Preferably, a pressure relief valve is further included, which is communicatively connected to the controller, and the phase change chamber can be connected to the outside world through the pressure relief valve. A critical pressure P3 is also preset in the controller, and P2≤P3; in step S4, it also includes: when P3≤p1, the controller issues the following instructions: the power module is shut down, the second water pump operates at the maximum design power, and the pressure relief valve is opened.

[0033] Through this setting, when an unexpected situation occurs, such as the failure of the power module or heat exchange module to control the temperature to continue to rise, and the pressure in the phase change chamber is too high, the controller can control the pressure relief valve to open and discharge the excess phase change gas in the phase change chamber, thereby avoiding irreversible damage to the charging cabinet.

[0034] Preferably, in step S4, the t1 also participates in the power regulation of the power module, and the power regulation method of the power module is: When t1<T1, t2<T3, p1<P1, the power module charges at the maximum power P max Work; When t1<T2, T3≤t2<T4, p1<P2; or P1≤p1<P2, t1<T2, t2<T4; or T1≤t1<T2, t2<T4, p1<P2, the controller controls the output power of the power module to be dynamically adjusted to ; When T2≤t1 or T4≤t2 or P2≤p1, the controller controls the power module to operate at the minimum design power.

[0035] Because the power module's output current is converted into internal energy due to DC resistance when passing through the charging cable, there's a possibility that the cable liquid cooling module's heat dissipation efficiency will fall below the charging cable's heat generation capacity due to excessive power module output. This configuration allows the charging cable's temperature control to be integrated into the power module's power control, thereby controlling the current in the charging cable and preventing excessive current from generating heat that exceeds the cable liquid cooling module's heat dissipation capacity.

[0036] Compared with the prior art, the present invention has the following beneficial effects: (1) During the charging process, the control module can collect the vehicle status, including battery model, battery charge percentage, etc.; it can also collect the temperatures t1 and t2 in the power module and charging cable in real time as reference information, and dynamically adjust the power of the cable liquid cooling module, power module and heat exchange liquid cooling module based on the above reference information to achieve a balance between charging efficiency and temperature control, which can not only ensure charging efficiency but also avoid excessive temperature leading to increased heat dissipation energy consumption.

[0037] (2) By dynamically regulating the cable liquid cooling module through the controller, the charging cable is kept within the preset optimal operating temperature range, thereby suppressing the increase in resistance in the charging cable and reducing the proportion of electrical energy converted into internal energy. This not only reduces the power loss during the charging process, but also reduces the heat dissipation burden of the cable liquid cooling module and the power consumption of heat dissipation, thereby reducing the heat dissipation burden and energy consumption without excessively reducing the charging efficiency.

[0038] (3) The controller dynamically controls the power of the power module and the water-heating and cooling module, ensuring the charging efficiency of the power module to the battery. The water-heating and cooling module is adjusted in real time according to the power module, which not only maintains the gas-liquid conversion balance in the phase change chamber, but also avoids the imbalance of heat generation and heat dissipation leading to excessive pressure in the phase change chamber, and does not waste heat dissipation capacity due to excessive power consumption, thereby improving the safety of the charging pile and reducing the power consumption of the water-heating and cooling module.

[0039] (4) By combining the charging cable temperature, the power module temperature and the phase change bin pressure, the output power of the power module is dynamically adjusted, so that the charging pile is ensured to be in the preset optimal working temperature range during the whole working process and each working component, which is beneficial to reduce the power consumption of the heat dissipation assembly and improve the charging efficiency, and the safety of the charging pile is ensured to the maximum extent. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the phase change cooling charging pile of the application; Figure 2 It is a schematic diagram of the cable liquid cooling module structure of the phase change cooling charging pile of the application; Figure 3 It is a schematic diagram of the operation process of the temperature control method of the phase change cooling charging pile of the application.

[0041] The illustration marks are explained as follows: 1, cabinet; 11, phase change bin; 12, pressure relief valve; 2, power module; 3, charging cable; 31, outer pipe; 32, inner cable; 4, cable liquid cooling module; 41, liquid cooling hose; 42, first water pump; 43, first heat exchange pipe; 5, heat exchange liquid cooling module; 51, second heat exchange pipe; 52, second water pump; 53, water tank; 6, control module; 61, controller; 62, first temperature sensor; 63, second temperature sensor; 64, pressure sensor; 7, phase change liquid. DETAILED DESCRIPTION

[0042] The application will be further described below in combination with specific embodiments. The drawings are only used for exemplary description, and the representation is only a schematic diagram, not a physical diagram, and cannot be understood as a limitation on the patent; in order to better illustrate the embodiments of the application, some components in the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some known structures and their descriptions in the drawings may be omitted.

[0043] The same or similar reference numerals in the drawings of the embodiments of the application correspond to the same or similar components; in the description of the application, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "left", "right" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the position relationship in the drawings are only used for exemplary description, and cannot be understood as a limitation on the patent, and for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0044] Embodiment 1 As shown in FIG. 1 and Figure 2The first embodiment of the phase change cooling charging pile is shown, comprising The cabinet body 1 is provided with a phase change bin 11 inside. The power module 2 is arranged at the bottom of the phase change bin 11. The charging cable 3 is arranged beside the cabinet body 1, and the charging cable 3 is electrically connected with the power module 2. The cable liquid cooling module 4 is partially arranged in the charging cable 3, and the rest of the cable liquid cooling module 4 is arranged at the bottom of the phase change bin 11. The heat exchange liquid cooling module 5 is partially arranged at the top of the phase change bin 11, and the rest of the heat exchange liquid cooling module 5 is located outside the cabinet body 1. The control module 6 includes a controller 61, a first temperature sensor 62 and a second temperature sensor 63. The first temperature sensor 62 is arranged in the charging cable 3. The controller 61 is electrically connected with the power module, the cable liquid cooling module 4, the heat exchange liquid cooling module 5, the first temperature sensor 62 and the second temperature sensor 63, respectively. The controller 61 can also be electrically connected with the charging vehicle. The phase change bin 11 is also filled with phase change liquid 7, the liquid level of the phase change liquid 7 is higher than the power module 2 and the cable liquid cooling module 4, and the liquid level of the phase change liquid 7 is lower than the heat exchange liquid cooling module 5.

[0045] Through this arrangement, when the electric vehicle is charging, the power module 2 converts the mains into high-voltage direct current and delivers it to the electric vehicle battery through the charging cable 3. At this time, the power module 2 and the charging cable 3 both generate heat. The power module 2 is immersed in the phase change liquid 7, and the heat generated is directly absorbed by the phase change liquid 7. The heat generated in the charging cable 3 is delivered to the phase change bin 11 by the cable liquid cooling module 4 and transferred to the phase change liquid 7. After absorbing heat, the phase change liquid 7 changes into phase change gas, which takes away the heat. The phase change gas rises and, after meeting the heat exchange liquid cooling module 5 at the top of the phase change bin 11, transfers the heat to the heat exchange liquid cooling module 5 and condenses into phase change liquid 7 falling back to the bottom of the phase change bin 11. The heat exchange liquid cooling module 5 exchanges the heat to the outside of the cabinet body 1. Due to the characteristics of the phase change liquid 7, the power module 2 immersed in the phase change liquid 7 is always in an environment not higher than the phase change temperature, ensuring the heat exchange efficiency throughout the process. On the other hand, the design of the phase change bin 11 provides redundancy for heat dissipation. When fast charging is needed, the power module 2 is in a high heat generation state, the vaporization speed in the phase change bin 11 is greater than the liquefaction speed, the phase change liquid 7 in the phase change bin 11 decreases and the phase change gas increases, but the phase change liquid 7 can still remain below the phase change temperature, and the power module 2 will not overheat. When the charging is completed and the power module 2 is in standby state, the power module 2 is in low power consumption or shutdown state. At this time, the liquefaction speed is greater than the vaporization speed, the phase change liquid 7 increases and the phase change gas decreases, until it returns to the balance state and waits for the next charging.

[0046] During the charging process, the control module 6 can collect the vehicle state, including the battery model, the battery power percentage, etc.; it can also collect the temperatures t1 and t2 in the power module 2 and the charging cable 3 in real time as reference information, and dynamically adjust the power of the cable liquid cooling module 4, the power module 2 and the heat exchange liquid cooling module according to the above reference information, so as to balance the charging efficiency and temperature control, which can ensure the charging efficiency and avoid the increase of heat dissipation energy consumption caused by high temperature.

[0047] As an embodiment of the present application, the phase change liquid 7 adopts an insulating phase change electronic fluorinated liquid.

[0048] As an embodiment of the present application, the cable liquid cooling module 4 and the heat exchange liquid cooling module 5 are provided with water cooling liquid, which includes but is not limited to ethylene glycol, mineral oil or single-phase fluorinated liquid.

[0049] As an embodiment of the present application, the cable liquid cooling module 4 includes a liquid cooling hose 41, a first water pump 42 and a first heat exchange pipeline 43, the charging cable 3 includes an outer pipe 31 and an inner cable 32, the liquid cooling hose 41 is in close abutment with the inner cable 32, the liquid cooling hose 41 is communicated with the first heat exchange pipeline 43 through the first water pump 42, and the first heat exchange pipeline 43 is arranged in the phase change bin 11 and located below the liquid level of the phase change liquid 7.

[0050] Through this arrangement, when charging, high-voltage current flows through the inner cable 32 of the charging cable 3 and generates heat, at this time, the first water pump 42 works to drive the water cooling liquid in the liquid cooling hose 41 and the first heat exchange pipeline 43 to circulate, the water cooling liquid in the liquid cooling hose 41 absorbs heat at the inner cable 32, and flows into the first heat exchange pipeline 43 under the driving of the first water pump 42, the first heat exchange pipeline 43 is immersed in the phase change liquid 7, the water cooling liquid in the first heat exchange pipeline 43 exchanges heat with the phase change liquid 7, and the water cooling liquid is quickly cooled and reenters the liquid cooling hose 41 under the action of the first water pump 42, which continuously dissipates heat for the inner cable 32.

[0051] As an embodiment of the present application, the heat exchange liquid cooling module 5 includes a second heat exchange pipeline 51, a second water pump 52 and a water tank 53, the second heat exchange pipeline 51 is communicated with the water tank 53 through the second water pump 52, the second heat exchange pipeline 51 is arranged in the phase change bin 11 and located above the liquid level of the phase change liquid 7, and the water tank 53 is arranged outside the cabinet 1.

[0052] The water tank 53 is a general term for water containers. In fact, the user can design the volume of the water tank 53 according to the actual use condition, or even use a water pool or other setting mode. Through this setting mode, when the phase change liquid 7 in the phase change bin 11 absorbs heat and phase changes, the phase change gas rises and contacts the second heat exchange pipeline 51 located at the top of the phase change bin 11. The second heat exchange pipeline 51 has low-temperature water cooling liquid flowing therein. The phase change gas releases heat and recondenses into phase change liquid 7. The phase change liquid 7 gathers to form liquid beads and flows back to the bottom of the phase change bin 11 under the action of gravity to participate in the phase change cycle again. Under the driving of the second water pump 52, the second heat exchange pipeline 51 and the water cooling liquid in the water tank 53 circulate. The water cooling liquid in the water tank 53 that has finished heat dissipation is continuously drawn into the second heat exchange pipeline 51 by the second water pump 52. The water cooling liquid in the second heat exchange pipeline 51 that has absorbed heat flows into the water tank 53 and is cooled in the water tank 53.

[0053] Embodiment 2 As Figure 3 The first embodiment of the temperature control method of the phase change cooling charging pile of the application is applied to the phase change cooling charging pile of embodiment 1, and includes the following steps. S1, setting the first temperature valve T1, the second temperature valve T2, the third temperature valve T3 and the fourth temperature valve T4 by the control module 6; S2, electrically connecting the power module 2 and the electric vehicle through the charging cable 3, and the power module 2 works; S3, the first temperature sensor 62 acquires the first temperature value t1 at the charging cable 3 and sends it to the controller 61, and the second temperature sensor 63 acquires the second temperature value t2 and sends it to the controller 61; S4, the controller 61 controls the cable liquid cooling module 4 to work according to the comparison result of the first temperature value t1 and the first temperature valve T1 and the second temperature valve T2, and controls the work of the heat exchange liquid cooling module 5 and the power module according to the comparison result of the second temperature value t2 and the third temperature valve T3 and the fourth temperature valve T4; S5, after receiving the charging end instruction, the controller 61 controls the power module 2 to stop working, and controls the cable liquid cooling module 4 and the heat exchange liquid cooling module 5 to continue working; when t1 < T1 and t2 < T3 are satisfied, the cable liquid cooling module 4 and the heat exchange liquid cooling module 5 both enter the standby state.

[0054] Through the setting mode, the user can preset the optimal working temperature interval according to the charging pile model. When the charging pile charges the electric car, the controller 61 controls the heat generation of the power module 2 and the charging cable 3 by dynamically adjusting the working efficiency of the power module 2; at the same time, the controller 61 controls the working of the cable liquid cooling module 4 and the heat exchange liquid cooling module 5 according to the heat generation of the power module 2 and the charging cable 3, ensures that the balance between heat generation and heat dissipation is achieved in the charging pile, and controls each component in the preset optimal working temperature interval, thereby inhibiting the resistance rise in the charging cable 3 and the power module 2, reducing the proportion of electric energy converted into internal energy, reducing the electric energy loss in the charging process, reducing the heat dissipation burden of the cable liquid cooling module 4 and the heat exchange liquid cooling module 5, reducing the power consumption of heat dissipation, thereby reducing the heat dissipation burden and energy consumption without excessively reducing the charging efficiency.

[0055] As an embodiment of the present application, the cable liquid cooling module 4 includes a liquid cooling hose 41, a first water pump 42 and a first heat exchange pipeline 43, the charging cable 3 includes an outer pipe and a plurality of inner cables, the liquid cooling hose 41 is in close contact with the inner cables, the liquid cooling hose 41, the first water pump 42 and the first heat exchange pipeline 43 are in communication to form a loop and are filled with water cooling liquid, and the first heat exchange pipeline 43 is arranged in the phase change bin 11 and located below the liquid level of the phase change liquid 7. In S4, the control method of the cable liquid cooling module 4 is specifically: When t1 When T1≤t1 When T2≤t1, the first water pump 42 operates at the maximum power.

[0056] ​The water coolant in the liquid cooling hose 41 absorbs heat in the charging cable 3 and flows to the first heat exchange pipeline 43 immersed in the phase change liquid 7 under the driving of the first water pump 42. The water coolant in the first heat exchange pipeline 43 releases heat to the phase change liquid 7 and then flows into the liquid cooling hose 41 again. Therefore, as the flow rate of the water coolant increases, the temperature exchange efficiency between the charging cable 3 and the phase change liquid 7 also increases. Through this arrangement, [T1, T2] is the optimal working temperature range of the charging cable 3. When the temperature is lower than T1, the temperature has little effect on the working efficiency of the charging cable 3, and T1 is close to the temperature of the charging cable 3 under normal conditions. When the temperature is lower than T1, active heat dissipation has little effect on the charging cable 3, so the first water pump 42 does not need to work at this time. When the charging cable 3 is in the temperature range [T1, T2], the controller 61 dynamically adjusts the first water pump 42. By increasing the power of the first water pump 42, the flow rate of the water coolant in the liquid cooling hose 41 and the first heat exchange pipeline 43 is increased, and the heat exchange capacity of the water coolant is increased, thereby improving the heat dissipation effect of the cable liquid cooling module 4. The heat dissipation rate can be adjusted synchronously with the heat generation efficiency of the charging cable 3. However, during the actual charging process, due to the environment, the actual charging rate and other reasons, the charging cable 3 may still exceed the optimal working temperature range. At this time, the first water pump 42 operates at the maximum set power to maximize the heat dissipation capacity of the cable heat exchange module.

[0057] As an embodiment of the present application, the cable liquid cooling module 4 further comprises a first flow rate meter, which is electrically connected to the controller 61.

[0058] Through this arrangement, the controller 61 can obtain the flow rate of the water coolant in the cable liquid cooling module 4 and thereby perform closed-loop adjustment on the first water pump 42.

[0059] As an embodiment of the present application, in step S4, wherein, I is the output current of the power module 2, R1 is the direct current resistance of the charging cable, P(t) is the dynamic adjustment power of the power module 2 at time t, V b V is the output voltage of the power module 2, ρ is the density of the water coolant, A is the cross-sectional area of the first heat exchange pipeline 43, Cp is the specific heat capacity of the water coolant, ΔT is the heat exchange temperature difference of the water coolant.

[0060] Through this arrangement, the controller 61 can calculate the heat generated by the charging cable 3 according to the output power of the power module 2 and adjust the heat dissipation capacity of the cable liquid cooling module 4 in real time, so that the charging cable 3 maintains a balance between heat generation and heat dissipation, and the temperature rise is avoided. The flow rate of the water coolant is adjusted according to the temperature, which can avoid energy waste caused by the heat dissipation efficiency being much higher than the heat generation efficiency.​

[0061] As an embodiment of the present application, the heat exchange liquid cooling module 5 comprises a second heat exchange pipeline 51, a second water pump 52 and a water tank 53, the second heat exchange pipeline 51 forms a communication loop with the water tank 53 through the second water pump 52, the second heat exchange pipeline 51 is arranged in the phase change bin 11 and above the liquid level of the phase change liquid 7, and the water tank 53 is arranged outside the cabinet 1; In S4, the control method of the heat exchange liquid cooling module 5 and the power module is specifically: When t2 ; When T3≤t2 , < T4, the controller 61 controls the output power of the power module 2 to be dynamically adjusted to ; the controller 61 dynamically adjusts the power of the second water pump 52, so that the water flow speed in the second heat exchange pipeline 51 is ; When T4≤t2, the controller 61 controls the power module 2 to operate at the minimum design power, and the second water pump 52 operates at the maximum design power.

[0062] When the phase change liquid 7 absorbs heat, it will be gasified into phase change gas, and the liquefaction efficiency of the phase change gas depends on the heat dissipation efficiency of the second heat exchange pipeline 51. When the gasification efficiency of the phase change liquid 7 is higher than the liquefaction efficiency of the phase change gas, it will cause the pressure in the phase change bin 11 to be too large, which has the risk of explosion; or the liquid level of the phase change liquid 7 is lower than the cable liquid cooling module 4 and the power module 2, which cannot absorb heat, resulting in high temperature and equipment damage.

[0063] Through this setting mode, the controller 61 can dynamically adjust the working conditions of the power module 2 and the heat exchange liquid cooling module 5 according to the temperature of the power module 2, so as to control the heat generation of the power module 2, avoid the temperature of the power module 2 being too high, and at the same time control the power of the heat exchange liquid cooling module 5, so as to ensure that the phase change gas liquefaction and the phase change liquid 7 gasification are balanced, and avoid the temperature in the phase change bin 11 being too high.

[0064] Under normal circumstances, the working power module 2 is in the temperature interval of [T3, T4], at this time the heat exchange liquid cooling module 5 dynamically adjusts the water flow speed according to the temperature of the power module 2, so that the heat exchange efficiency of the water cooling liquid in the second heat exchange pipeline 51 is equivalent to the heat generation efficiency of the power module 2, and the gas-liquid conversion balance in the phase change bin 11 is maintained. Since the power module 2 generates heat as the main heat source during the operation of the charging cabinet, only the temperature of the power module 2 can be considered as the control source at this time; When the temperature of the power module 2 exceeds T4, it indicates that the heat dissipation capacity of the phase change liquid 7 cannot bear the heat production load of the power module 2 at this time, and the output of the power module 2 is adjusted to the minimum design value at this time. The minimum design power can include standby or shutdown conditions, so as to minimize the heat production of the power module 2, and the second water pump 52 works at the highest power to improve the heat dissipation efficiency of the heat exchange liquid cooling module 5, thereby improving the liquefaction efficiency of the phase change gas and maintaining the gas-liquid balance in the phase change bin 11.

[0065] As an embodiment of the present application, in step S4, the dynamic adjustment power of the power module 2 is specifically: ; Wherein, P max is the maximum allowed charging power of the battery, k is the attenuation coefficient, and SOC is the percentage of the remaining capacity of the battery to the nominal capacity.

[0066] Through this setting mode, the output power of the power module 2 is dynamically adjusted according to the battery capacity of the charged battery, which is beneficial to the battery health and will not cause too much influence on the charging efficiency.

[0067] As an embodiment of the present application, the heat exchange liquid cooling module 5 is also provided with a second flow rate meter, and the second flow rate meter is electrically connected with the controller 61.

[0068] As an embodiment of the present application, in step S4, the dynamic adjustment flow rate of the second water pump 52 is: ; Wherein, is the total heat production power of the supercharged charging pile phase change bin 11 at t time, is the density of the cooling water, is the cross-sectional area of the second heat exchange pipeline, is the specific heat capacity of the cooling water, is the heat exchange temperature difference of the cooling water.

[0069] Through this setting mode, the second water pump 52 can adjust the flow rate in real time according to the heat production in the phase change bin 11, so as to make the heat dissipation efficiency and the heat production efficiency flat, and maintain the gas-liquid conversion balance in the phase change bin 11.

[0070] As an embodiment of the present application, , ; Wherein, is the heat production power of the power module 2 at t time, I is the charging current, R2 is the direct current resistance of the power module 2, Pe is the optimal charging power at t time, V b is the voltage of the electric vehicle battery, is the heat production power of the charging cable at t time, is the total heat production power of the phase change indoor charging pile at time t.

[0071] As an embodiment of the present application, the control module 6 further comprises a pressure sensor 64 for obtaining the first pressure value p1, the pressure sensor 64 is arranged at the top of the phase change bin 11, the pressure sensor 64 is electrically connected with the controller 61, the controller 61 is pre-set with a first pressure valve P1 and a second pressure valve P2, at this time in S4, the control method of the heat exchange liquid cooling module 5 and the power module is specifically: When t2 is working; When T3≤t2 , < , the controller 61 controls the second water pump 52 to work, so that the water flow velocity in the second heat exchange pipeline 51 is ; When T4≤t2 or P2≤p1, the controller 61 controls the power module 2 to run at the minimum design power, and the second water pump 52 works at the maximum design power.

[0072] The first pressure valve and the second pressure valve here both refer to the set numerical threshold value instead of the physical valve. Through this setting mode, the controller 61 can directly monitor the gas-liquid relationship in the phase change bin 11 through the pressure sensor 64, and feed back the pressure in the phase change bin 11 to participate in the dynamic adjustment of the power module 2 and the heat exchange liquid cooling module 5, so as to prevent the risk of leakage or even explosion due to excessive pressure in the phase change bin 11, and further improve the safety of the charging pile.

[0073] Embodiment 3 The following is a second embodiment of a temperature control method of a phase change cooling charging pile of the present application, which is similar to embodiment 2, the difference is that the charging pile further comprises a pressure relief valve 12, and the dynamic adjustment mode of the power module 2 is different.

[0074] As an embodiment of the present application, the pressure relief valve 12 is in communication connection with the controller 61, the phase change bin 11 can be communicated with the outside through the pressure relief valve 12, and the controller 61 is further pre-set with a critical pressure P3, P2≤P3; in step S4, further comprising: when P3≤p1, the controller 61 issues the following instructions: the power module 2 is stopped, the second water pump 52 works at the maximum design power, and the pressure relief valve 12 is opened.

[0075] Through the setting mode, when an unexpected situation occurs, such as power module 2 or heat exchange module regulation failure causes temperature to continuously rise, the pressure in phase change bin 11 is too large, controller 61 can control pressure relief valve 12 to open, and the excessive phase change gas in phase change bin 11 is discharged, so that irreversible damage to the charging cabinet is avoided.

[0076] As an embodiment of the present application, in step S4, t1 also participates in the power regulation of power module 2, and the power regulation method of power module 2 is: When t1 < T1, t2 < T3, and p1 < P1, power module 2 is in maximum charging power P max Working; When t1 < T2, T3≤t2 < T4, and p1 < P2; or P1≤p1 < P2, t1 < T2, t2 < T4; or T1≤t1 < T2, t2 < T4, and p1 < P2, controller 61 controls the output power of power module 2 to dynamically adjust to ; When T2≤t1 or T4≤t2 or P2≤p1, controller 61 controls power module 2 to run at the minimum design power.

[0077] Since the output current of power module 2 will also be converted into internal energy when passing through charging cable 3 due to direct current resistance, there is a possibility that the output power of power module 2 is too high, which causes the heat dissipation efficiency of cable liquid cooling module 4 to be lower than the heat generation capacity of charging cable 3. Through this setting mode, the temperature regulation of charging cable 3 also participates in the power regulation of power module 2, so as to control the size of the current in charging cable 3, and avoid the heat generation of charging cable 3 due to excessive current from exceeding the heat dissipation capacity of cable liquid cooling module 4.

[0078] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those of ordinary skill in the art. Here, it is not necessary and impossible to exhaust all embodiments. Any modification, equivalent replacement and improvement made within the spirit and principles of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A phase change cooling charging pile, characterized in that: including a cabinet body, inside which a phase change chamber is provided; a power module, which is installed at the bottom of the phase change chamber; a charging cable, which is installed beside the cabinet body, and the charging cable is electrically connected to the power module; a cable liquid cooling module, part of which is installed inside the charging cable, and the rest of the cable liquid cooling module is installed at the bottom of the phase change chamber; a heat exchange liquid cooling module, part of which is installed at the top of the phase change chamber, and the rest of the heat exchange liquid cooling module is located outside the cabinet body; a control module, which includes a controller, a first temperature sensor and a second temperature sensor. The first temperature sensor is installed inside the charging cable, and the controller is electrically connected to the power module, the cable liquid cooling module, the heat exchange liquid cooling module, the first temperature sensor and the second temperature sensor respectively. The controller can also be electrically connected to a charging vehicle; a phase change liquid is further filled in the phase change chamber. The liquid level of the phase change liquid is higher than the power module and the cable liquid cooling module, and the liquid level height of the phase change liquid is lower than the heat exchange liquid cooling module.

2. A temperature control method for a phase change cooling charging pile, characterized in that: Applied to the phase change cooling charging pile as described in claim 1, including: S1. Set a first temperature valve T1, a second temperature valve T2, a third temperature valve T3 and a fourth temperature valve T4 through the control module; S2. Electrically connect the power module with the electric vehicle through the charging cable, and the power module works; S3. The first temperature sensor obtains a first temperature value t1 at the charging cable and transmits it to the controller, and the second temperature sensor obtains a second temperature value t2 and transmits it to the controller; S4. The controller controls the operation of the cable liquid cooling module according to the comparison result of the first temperature value t1 with the first temperature valve T1 and the second temperature valve T2. The controller controls the operation of the heat exchange liquid cooling module and the power module according to the comparison result of the second temperature value t2 with the third temperature valve T3 and the fourth temperature valve T4; S5. After receiving a charging end instruction, the controller controls the power module to stop operating, and controls the cable liquid cooling module and the heat exchange liquid cooling module to continue operating; when t1 < T1 and t2 < T3 are satisfied, both the cable liquid cooling module and the heat exchange liquid cooling module enter the standby state.

3. The temperature control method for a phase change cooling charging pile according to claim 2, characterized in that: The cable liquid cooling module includes a liquid cooling hose, a first water pump and a first heat exchange pipeline. The charging cable includes an outer pipe and several inner cables. The liquid cooling hose is in close contact with the inner cables. The liquid cooling hose, the first water pump and the first heat exchange pipeline are interconnected to form a loop and filled with a water cooling liquid. The first heat exchange pipeline is installed in the phase change chamber and below the liquid level of the phase change liquid; In S4, the control method of the cable liquid cooling module is specifically as follows: When t1 < T1, the first water pump is in the standby state; When T1 ≤ t1 < T2, the controller dynamically adjusts the power of the first water pump, and the first water pump controls the flow rate of the water coolant to be ; When T2 ≤ t1, the first water pump operates at the maximum power.

4. The temperature control method for a phase change cooling charging pile according to claim 3, characterized in that: In step S4, ; in, ; I is the output current of the power module, R1 is the DC resistance of the charging cable, is the dynamic adjustment power of the power module at time t, V b is the output voltage of the power module, is the density of the water coolant, is the cross-sectional area of ​​the first heat exchange pipeline, is the specific heat capacity of the water coolant, is the heat exchange temperature difference of the water coolant.

5. The temperature control method for a phase change cooling charging pile according to claim 3, characterized in that: The heat exchange liquid cooling module includes a second heat exchange pipeline, a second water pump and a water tank. The second heat exchange pipeline forms a communication loop with the water tank through the second water pump. The second heat exchange pipeline is installed in the phase change chamber and is located above the liquid level of the phase change liquid. The water tank is installed outside the cabinet. In S4, the control method of the heat exchange liquid cooling module and the power module is specifically as follows: When t2 < T3, the power module operates at the maximum charging power ; When T3≤t2<T4, the controller controls the output power of the power module to be dynamically adjusted to , < ; The controller dynamically adjusts the power of the second water pump so that the water flow rate in the second heat exchange pipeline is ; When T4≤t2, the controller controls the power module to operate at the minimum design power, and the second water pump to operate at the maximum design power.

6. The temperature control method for a phase change cooling charging pile according to claim 4 or 5, characterized in that: In step S4, the dynamic adjustment power of the power module is specifically: ； Among them, P max is the maximum allowable charging power of the battery, k is the attenuation coefficient, and SOC is the percentage of the remaining battery capacity to the nominal capacity.

7. The temperature control method for a phase change cooling charging pile according to claim 5, characterized in that: In step S4, the dynamically adjusted flow rate of the second water pump is: ； in, is the total heat generation power of the supercharging charging pile phase change warehouse at time t, is the density of cooling water, is the cross-sectional area of ​​the second heat exchange pipe, is the specific heat capacity of cooling water, is the heat exchange temperature difference of cooling water.

8. The temperature control method for a phase change cooling charging pile according to claim 5, characterized in that: The control module further includes a pressure sensor for obtaining a first pressure value p1. The pressure sensor is installed on the top of the phase change chamber and is electrically connected to the controller. The controller is pre-set with a first pressure valve P1 and a second pressure valve P2. At this time, in S4, the control method of the heat exchange liquid cooling module and the power module is specifically as follows: When t2 < T3 and p1 < P1, the power module operates at the maximum charging power ; When T3≤t2<T4, p1<P2; or P1≤p1<P2, t2<T4, the controller controls the output power of the power module to be dynamically adjusted to , < The controller controls the second water pump to operate so that the water flow rate in the second heat exchange pipe is ; When T4≤t2 or P2≤p1, the controller controls the power module to operate at the minimum design power, and the second water pump to operate at the maximum design power.

9. The temperature control method for a phase change cooling charging pile according to claim 8, characterized in that: It also includes a pressure relief valve, which is in communication with the controller. The phase change chamber can be connected to the outside world through the pressure relief valve. The controller is also preset with a critical pressure P3, where P2≤P3; In step S4, it also includes: when P3≤p1, the controller issues the following instructions: the power module is shut down, the second water pump operates at the maximum design power, and the pressure relief valve is opened.

10. The temperature control method for a phase change cooling charging pile according to claim 8, characterized in that: In step S4, the t1 also participates in the power regulation of the power module, and the power regulation method of the power module is: When t1<T1, t2<T3, p1<P1, the power module charges at the maximum power P max Work; When t1<T2, T3≤t2<T4, p1<P2; or P1≤p1<P2, t1<T2, t2<T4; or T1≤t1<T2, t2<T4, p1<P2, the controller controls the output power of the power module to be dynamically adjusted to ; When T2≤t1 or T4≤t2 or P2≤p1, the controller controls the power module to operate at the minimum design power.

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