PCS and battery liquid cooling control method and system

Abstract

The invention discloses a PCS and a battery liquid cooling control method and system. The PCS and battery liquid cooling control method comprises the steps of obtaining temperatures of a PCS side and a battery side, and judging whether the battery side needs to be cooled or not based on a comparison result of the battery side temperature and a first temperature threshold value; judging whether the PCS side needs to be cooled or not based on a comparison result of the PCS side and a second temperature threshold value; if the battery side needs to be cooled, the environment temperature is obtained; a working mode is selected based on comparison of the environment temperature with a third temperature threshold value and a fourth temperature threshold value; if the environment temperature is smaller than the third temperature threshold value, a full-free cold operation mode is selected; if the environment temperature is larger than the third temperature threshold value and smaller than the fourth temperature threshold value, an independent cooling mode is selected; if the environment temperature is larger than a fourth temperature threshold value, a water mixing operation mode is selected; and if the PCS side needs to be cooled, only the PCS side is cooled in a free cold operation mode. Different working modes are selected by acquiring the environment temperature, so that the working efficiency is improved, and high-temperature derating cannot occur when liquid cooling is adopted on the PCS side.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid cooling control of energy storage systems, and in particular to a PCS and battery liquid cooling control method and system. Background Art

[0002] At present, the thermal management of electrochemical energy storage systems mainly adopts air-cooled air conditioning cooling or liquid-cooled battery packs, while PCS is mostly air-cooled. This traditional cooling method is greatly affected by the environment, especially in terms of waterproof and dustproof and temperature adaptability. The temperature difference of the battery cells in the air-cooled system is large, resulting in low efficiency of PCS, which in turn affects the life of the entire energy storage system.

[0003] Moreover, in order to achieve effective air cooling, a larger space is usually required to arrange the air duct and waterproof shutters, which not only reduces the space utilization, but also easily affects the normal operation of the system due to dirt and blockage. Summary of the invention

[0004] To solve the above problems, the first aspect of the present application provides a PCS and battery liquid cooling control method, including:

[0005] Obtain the temperatures of the PCS side and the battery side, and determine whether the battery side needs to be cooled based on a comparison result between the battery side temperature and a first temperature threshold; and determine whether the PCS side needs to be cooled based on a comparison result between the PCS side temperature and a second temperature threshold;

[0006] If the battery side needs to be cooled, the ambient temperature is obtained; the working mode is selected based on the comparison between the ambient temperature and the third temperature threshold and the fourth temperature threshold; the third temperature threshold is less than the fourth temperature threshold; if the ambient temperature is less than the third temperature threshold, the full free cooling operation mode is selected; if the ambient temperature is greater than the third temperature threshold and less than the fourth temperature threshold, the independent cooling mode is selected; if the ambient temperature is greater than the fourth temperature threshold, the mixed water operation mode is selected;

[0007] If the PCS side needs to be cooled, only the PCS side is cooled in free cooling mode.

[0008] Wherein, the full free cold operation mode comprises the following steps:

[0009] The electric three-way valve controls the connection between port 1 and port 2;

[0010] The fan starts to lower the temperature of the liquid supply on the battery side;

[0011] The battery side water pump and the PCS side water pump are turned on until the battery side temperature is lower than the first temperature threshold.

[0012] Wherein, the independent cooling mode comprises the following steps:

[0013] The electric three-way valve controls the connection between port 1 and port 3;

[0014] Compressor startup controls the liquid supply temperature; compressor suction superheat is controlled based on EEV, and compressor exhaust saturation temperature is controlled based on the fan;

[0015] The battery side water pump and the PCS side water pump are turned on until the battery side temperature is lower than the first temperature threshold.

[0016] Wherein, the mixed water operation mode comprises the following steps:

[0017] The electric three-way valve controls the connection between port 1 and port 3;

[0018] Compressor startup controls the liquid supply temperature; compressor suction superheat is controlled based on EEV, and compressor exhaust saturation temperature is controlled based on the fan;

[0019] The battery side water pump and the PCS side water pump are turned on, and the electric ball valve is opened to control the PCS side liquid supply temperature until the battery side temperature is lower than the first temperature threshold.

[0020] The cooling of only the PCS side in free cooling operation mode comprises the following steps:

[0021] The electric three-way valve controls the connection between port 1 and port 3;

[0022] The fan starts to control the liquid supply temperature on the PCS side, and the fan can only run at the minimum speed;

[0023] The battery side water pump and the PCS side water pump are turned on until the PCS side temperature is lower than the second temperature threshold.

[0024] Wherein, the compressor and the EEV are both controlled by PID; the control unit obtains the liquid supply temperature and then adjusts the working power of the compressor; the control unit obtains the suction superheat of the compressor and adjusts the valve opening of the EEV.

[0025] Wherein, it also includes a pressure sensor to obtain water pressure, and if the water pressure is less than a preset pressure value, the liquid replenishing pump is controlled to replenish liquid.

[0026] Among them, the PCS and battery liquid cooling control method also includes a heating mode; the heating mode is implemented based on a PTC thermistor.

[0027] The second aspect of the present application further provides a PCS and battery liquid cooling control system, which can apply the PCS and battery liquid cooling control method as described in any of the above items, including:

[0028] An electric three-way valve, wherein port 1 of the electric three-way valve is connected to the battery liquid inlet, port 2 of the electric three-way valve is connected to the PCS liquid inlet, and port 3 of the electric three-way valve is connected to the first end of the plate exchanger;

[0029] A water cooler, one end of which is connected to the PCS liquid inlet, the other end of which is connected to one end of the PCS circulating water pump, and the other end of which is connected to the PCS liquid return port;

[0030] A compressor, one end of the compressor is connected to the second end of the plate exchanger, and the other end of the compressor is connected to one end of the condenser;

[0031] EEV, one end of the EEV is connected to the other end of the condenser, the other end of the EEV is connected to the third end of the plate changer, the fourth end of the plate changer is connected to one end of the battery circulating water pump, and the other end of the battery circulating water pump is connected to the battery liquid return port.

[0032] Among them, it also includes an on-off electric ball valve, a regulating electric ball valve and a fan; one end of the on-off electric ball valve is connected to the side of the battery circulating water pump close to the plate changer, and the other end of the on-off electric ball valve is connected to the side of the PCS circulating water pump close to the water cooler; the on-off electric ball valve is used to control whether the water cooled by the water cooler flows into the battery circulating water pump; one end of the regulating electric ball valve is connected to the battery liquid return port, and the other end of the regulating electric ball valve is connected to the PCS liquid return port; the regulating electric ball valve is used to adjust the liquid return ratio of the battery liquid return port and the PCS liquid return port; the fan is used to cool the condenser.

[0033] Beneficial effects of the present invention: Different from the prior art, the PCS and battery liquid cooling control method of the present invention includes: obtaining the temperature of the PCS side and the battery side, judging whether the battery side needs to be cooled based on the comparison result of the battery side temperature and the first temperature threshold; judging whether the PCS side needs to be cooled based on the comparison result of the PCS side and the second temperature threshold; if the battery side needs to be cooled, then obtaining the ambient temperature; selecting the working mode based on the comparison of the ambient temperature with the third temperature threshold and the fourth temperature threshold; the third temperature threshold is less than the fourth temperature threshold; if the ambient temperature is less than the third temperature threshold, selecting the full free cooling operation mode; if the ambient temperature is greater than the third temperature threshold and less than the fourth temperature threshold, selecting the independent cooling mode; if the ambient temperature is greater than the fourth temperature threshold, selecting the mixed water operation mode; if the PCS side needs to be cooled, then only the PCS side is cooled in the free cooling operation mode. The work efficiency is improved by obtaining the ambient temperature to select different working modes, and the PCS side will not experience high temperature derating when liquid cooling is used. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A schematic flow chart of the first embodiment of the PCS and battery liquid cooling control method provided in this application;

[0035] Figure 2 A schematic diagram of a flow chart of an embodiment of a full free cooling operation mode provided in the present application;

[0036] Figure 3 A schematic diagram of a flow chart of an embodiment of an independent cooling mode provided in the present application;

[0037] Figure 4 A schematic diagram of a flow chart of an embodiment of a mixed water operation mode provided in this application;

[0038] Figure 5 A flow chart of an embodiment of cooling only the PCS side in a free cooling operation mode provided by the present application;

[0039] Figure 6 This is a structural schematic diagram of an embodiment of a PCS and battery liquid cooling control system provided by the present application;

[0040] Figure 7 for Figure 6 Schematic diagram of water flow in full free cooling operation mode;

[0041] Figure 8 for Figure 6 Schematic diagram of water flow in independent cooling mode;

[0042] Fig. 9 for Figure 6 Schematic diagram of water flow in mixed water operation mode. DETAILED DESCRIPTION

[0043] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0044] like Figure 1 As shown, Figure 1 The flowchart of the first embodiment of the PCS and battery liquid cooling control method provided in this application includes the following steps:

[0045] S1: Obtain the temperature of the PCS (power conversion system) side and the battery side, and determine whether the battery side needs to be cooled based on the comparison result between the battery side temperature and the first temperature threshold; determine whether the PCS side needs to be cooled based on the comparison result between the PCS side and the second temperature threshold.

[0046] The actual temperature of the PCS side and the battery side is obtained in real time through the temperature sensor. The temperature sensor transmits the temperature data to the control unit. After receiving the temperature data, the control unit will compare the temperature of the battery side with the pre-set first temperature threshold; similarly, the temperature of the PCS side will be compared with the second temperature threshold; if the temperature of the battery side exceeds the first temperature threshold, it is judged that the battery side needs to be cooled down, and if the temperature of the PCS side exceeds the second temperature threshold, it is judged that the PCS side needs to be cooled down. It should be clarified that this application does not limit the specific values ​​of the first temperature threshold and the second temperature threshold, and users can set them according to specific circumstances.

[0047] S2: If the battery side needs to be cooled, the ambient temperature is obtained; the working mode is selected based on the comparison between the ambient temperature and the third temperature threshold and the fourth temperature threshold; the third temperature threshold is less than the fourth temperature threshold; if the ambient temperature is less than the third temperature threshold, the full free cooling operation mode is selected; if the ambient temperature is greater than the third temperature threshold and less than the fourth temperature threshold, the independent cooling mode is selected; if the ambient temperature is greater than the fourth temperature threshold, the mixed water operation mode is selected;

[0048] If it is detected that the temperature of the battery side exceeds the first temperature threshold, it is determined that the battery side needs to be cooled; the ambient temperature is compared with the third temperature threshold and the fourth temperature threshold to select a different working mode.

[0049] Fully free cooling operation mode: Utilizes natural cooling in low temperature environments, consumes almost no additional electricity, and greatly improves the energy efficiency of the system.

[0050] Independent cooling mode: Suitable for medium temperature environments, it provides the necessary cooling capacity through compressor refrigeration, which not only ensures the cooling effect but also avoids unnecessary energy waste.

[0051] Mixed water operation mode: Provides greater cooling capacity in high temperature environments, ensuring stable operation of the system under extreme conditions, while reducing energy consumption by optimizing the fluid path.

[0052] By intelligently selecting the working mode that best suits the current environment, the equipment can be prevented from being in a high-load state for a long time, thereby extending the service life of the compressor, fan and other components.

[0053] S3: If the PCS side needs to be cooled, only the PCS side is cooled in free cooling mode; low-temperature air in the environment is used for cooling, minimizing the use of mechanical refrigeration equipment and further reducing energy consumption; liquid cooling replaces traditional air cooling, which not only better prevents water and dust, but also improves the protection level of the PCS, further enhancing the environmental adaptability of the system.

[0054] In summary, the PCS and battery liquid cooling control method of this embodiment includes: obtaining the temperature of the PCS side and the battery side, judging whether the battery side needs to be cooled based on the comparison result of the battery side temperature and the first temperature threshold; judging whether the PCS side needs to be cooled based on the comparison result of the PCS side and the second temperature threshold; if the battery side needs to be cooled, then obtaining the ambient temperature; selecting the working mode based on the comparison of the ambient temperature with the third temperature threshold and the fourth temperature threshold; the third temperature threshold is less than the fourth temperature threshold; if the ambient temperature is less than the third temperature threshold, selecting the full free cooling operation mode; if the ambient temperature is greater than the third temperature threshold and less than the fourth temperature threshold, selecting the independent cooling mode; if the ambient temperature is greater than the fourth temperature threshold, selecting the mixed water operation mode; if the PCS side needs to be cooled, then only the PCS side is cooled in the free cooling operation mode. The work efficiency is improved by obtaining the ambient temperature to select different working modes, and the PCS side will not experience high temperature derating when liquid cooling is used.

[0055] In one embodiment, if Figure 2 As shown, Figure 2 The schematic diagram of the process of an embodiment of the full free cold operation mode provided in the present application includes the following steps:

[0056] Step S211: The electric three-way valve controls the connection between port 1 and port 2; the coolant flows directly to the battery side after flowing out of the plate converter without passing through the compressor or condenser. This fluid path selection allows the coolant to be naturally cooled by the low-temperature air in the environment;

[0057] Step S212: The fan is started to reduce the temperature of the battery-side liquid supply; the fan is started to increase air flow and help the coolant absorb more cold air from the environment. The function of the fan is to accelerate the heat exchange between the coolant and the outside air, thereby more effectively reducing the temperature of the battery-side liquid supply.

[0058] Step S213: The battery side water pump and the PCS side water pump are turned on until the battery side temperature is lower than the first temperature threshold; the battery side water pump and the PCS side water pump are started to ensure that the coolant circulates throughout the system. The battery side water pump pushes the coolant through the battery module to take away the heat; the PCS side water pump maintains the circulation of the coolant on the PCS side to ensure the cooling effect of the entire system; the temperature of the battery side is continuously monitored until it drops below the first temperature threshold, and the system stops the operation of the fan and water pump.

[0059] Using low-temperature air in the environment for cooling consumes almost no additional electricity, greatly improving the energy efficiency of the system. There is no need to start the compressor, which reduces the wear of the compressor and other related mechanical parts and extends their service life.

[0060] In one embodiment, if Figure 3 As shown, Figure 3The flowchart of an embodiment of the independent cooling mode provided in this application includes the following steps:

[0061] Step S221: The electric three-way valve controls the connection between port 1 and port 3; the coolant flows out of the plate converter, passes through the compressor and condenser, and then flows to the battery side. This fluid path selection enables the coolant to effectively exchange heat through the refrigerant cycle, thereby achieving more efficient cooling;

[0062] Step S222: The compressor starts to control the liquid supply temperature; the compressor suction superheat is controlled based on the EEV (electronic expansion valve), and the compressor exhaust saturation temperature is controlled based on the fan.

[0063] The function of the compressor is to increase the pressure and temperature of the refrigerant so that it releases heat in the condenser and then enters the evaporator after being regulated by the EEV, absorbing heat from the coolant in the process, thereby reducing the supply liquid temperature.

[0064] EEV is adjusted according to the compressor suction superheat to ensure that the refrigerant is in an appropriate superheat state before entering the compressor. This helps optimize the compressor's operating efficiency, prevent liquid hammer, and protect the compressor from damage; it starts the fan to help the condenser dissipate heat and control the saturation temperature of the compressor exhaust.

[0065] The function of the fan is to accelerate the air flow, take away the heat in the condenser, and ensure that the compressor operates within a safe operating temperature range. At the same time, the speed of the fan can be adjusted according to actual needs to maintain the optimal exhaust saturation temperature.

[0066] Step S223: the battery side water pump and the PCS side water pump are turned on until the battery side temperature is lower than the first temperature threshold; this step is the same as step S213 and will not be repeated here.

[0067] Compressor refrigeration can quickly reduce the temperature of the coolant, ensure that the temperature on the battery side drops quickly, and prevent performance degradation or damage caused by high temperature; through the coordinated work of EEV and fan, the suction superheat and exhaust saturation temperature of the compressor can be accurately controlled to ensure the efficiency and stability of the refrigeration process.

[0068] In one embodiment, if Figure 4 As shown, Figure 4 The flow chart of an embodiment of the mixed water operation mode provided in this application includes the following steps:

[0069] Step S231: the electric three-way valve controls the connection between port 1 and port 3; it is the same as step S221 and will not be repeated here.

[0070] Step S232: start the compressor to control the liquid supply temperature; control the compressor suction superheat based on the EEV, and control the compressor exhaust saturation temperature based on the fan; the same as step S222, which will not be repeated here.

[0071] Step S233: The battery side water pump and the PCS side water pump are turned on, and the electric ball valve is turned on to control the liquid supply temperature on the PCS side until the battery side temperature is lower than the first temperature threshold; the electric ball valve is turned on to adjust the coolant flow through the PCS side. The function of the electric ball valve is to control the liquid supply temperature on the PCS side to ensure that the temperature on the PCS side is also within a suitable range. By adjusting the opening of the electric ball valve, the amount of coolant flowing into the PCS side can be accurately controlled to achieve the desired cooling effect.

[0072] By adjusting the electric ball valve, the battery side and the PCS side can be cooled simultaneously, ensuring that both key components can operate within an appropriate temperature range; by precisely controlling the fan speed, water pump flow and the opening of the electric ball valve, the battery side and the PCS side can be kept within a stable temperature range, improving the reliability and stability of the system.

[0073] In one embodiment, if Figure 5 As shown, Figure 5 The schematic diagram of a flow chart of an embodiment of cooling only the PCS side in a free cooling operation mode provided in this application includes the following steps:

[0074] Step S31: the electric three-way valve controls the connection between port 1 and port 3;

[0075] Step S32: The fan is started to control the liquid supply temperature on the PCS side. The fan can only run at the minimum speed. The function of the fan is to increase air flow and help the coolant absorb more cold air from the environment, thereby reducing the temperature of the liquid supply on the PCS side. Running at the minimum speed can reduce power consumption while providing necessary air flow to assist in cooling.

[0076] Step S33: The battery side water pump and the PCS side water pump are turned on until the PCS side temperature is lower than the second temperature threshold; the system continuously monitors the PCS side temperature until it drops below the second temperature threshold; once the temperature reaches the target value, the system can stop the fan and water pump, or keep running at a low speed to maintain temperature stability.

[0077] The fan only runs at the minimum speed, which significantly reduces power consumption and achieves the purpose of energy saving; the low-temperature air in the environment is used for cooling, which minimizes the use of mechanical refrigeration equipment and further reduces energy consumption; by precisely controlling the fan speed and water pump flow, the PCS side can be kept within a stable temperature range, improving the reliability and stability of the system.

[0078] In one embodiment, the compressor and EEV are both controlled by PID (proportional-integral-differential); the control unit obtains the liquid supply temperature and then adjusts the working power of the compressor; the control unit obtains the suction superheat of the compressor to adjust the valve opening of the EEV; the control unit continuously obtains the latest liquid supply temperature and suction superheat data, and adjusts the working power of the compressor and the valve opening of the EEV in real time according to the PID algorithm to ensure that the system is always in the best working state. The PID control algorithm is common knowledge for those skilled in the art and will not be described in detail.

[0079] Through PID control, the system can respond quickly to temperature changes, keep the liquid supply temperature within the set target range, and ensure that the battery side and PCS side work in a stable temperature environment; by precisely controlling the EEV valve opening, it ensures that the compressor suction superheat is always within a safe range, preventing liquid refrigerant from entering the compressor, avoiding the occurrence of liquid hammer, and extending the service life of the compressor.

[0080] In one embodiment, a pressure sensor is also included to obtain water pressure. If the water pressure is less than a preset pressure value, the refilling water pump is controlled to perform refilling. If the water pressure is lower than the preset pressure value, the control unit will trigger the refilling water pump to start. The refilling water pump extracts coolant from the liquid storage tank and injects it into the system until the water pressure returns to a normal range. During the refilling process, the control unit continues to monitor the water pressure to ensure that there is no excessive refilling to avoid excessive pressure in the system. Once the water pressure returns to above the preset pressure value, the control unit will stop the operation of the refilling water pump to keep the water pressure in the system stable. In another embodiment, the control unit can also set a certain hysteresis range to prevent the water pressure from fluctuating frequently near the critical value, causing the refilling water pump to start and stop frequently.

[0081] By real-time monitoring of water pressure and automatic refilling, low-pressure alarms caused by poor exhaust or a small amount of leakage can be effectively prevented to ensure the normal operation of the system; timely refilling can avoid system shutdowns caused by low pressure, reducing unnecessary downtime and maintenance costs.

[0082] In one embodiment, the PCS and battery liquid cooling control method also includes a heating mode; the heating mode is implemented based on a PTC thermistor; the temperature sensor in the system monitors the temperature of the battery side and the PCS side in real time, and feeds back the data to the control unit; the control unit determines whether it is necessary to start the heating mode based on a pre-set target temperature range; if the temperature is detected to be lower than the set minimum operating temperature threshold, the control unit triggers the PTC thermistor to start; the PTC thermistor starts to generate heat, and the heat is transferred to the battery side and / or PCS side through the coolant to increase its temperature; the control unit dynamically adjusts the heating power of the PTC thermistor based on the gap between the actual temperature and the target temperature; when the temperature approaches the target temperature, the heating power is reduced to prevent overheating; when the temperature continues to drop, the heating power is increased to ensure that the temperature rises rapidly.

[0083] PTC thermistors have a self-limiting temperature characteristic, that is, as the temperature rises, the resistance increases and the current decreases, thereby automatically limiting the maximum temperature to prevent overheating; PTC thermistors have a high heating efficiency and can quickly heat up in a short period of time, reducing heating time and improving energy utilization efficiency.

[0084] The present application also provides a PCS and battery liquid cooling control system, which can apply the PCS and battery liquid cooling control method described in any of the above embodiments, such as Figure 6 As shown, Figure 6 The structural diagram of an embodiment of the PCS and battery liquid cooling control system provided in this application includes:

[0085] Electric three-way valve, port 1 of the electric three-way valve is connected to the battery liquid inlet, port 2 of the electric three-way valve is connected to the PCS liquid inlet, and port 3 of the electric three-way valve is connected to the first end of the plate exchanger.

[0086] Water cooler, one end of the water cooler is connected to the PCS liquid inlet, the other end of the water cooler is connected to one end of the PCS circulating water pump, and the other end of the PCS circulating water pump is connected to the PCS liquid return port; in free cooling mode, the water cooler cools down through the ambient air, and the coolant flows to the PCS side after passing through the water cooler to take away the heat; the water cooler and the PCS circulating water pump work together to ensure that the coolant circulates on the PCS side to maintain a suitable temperature.

[0087] Compressor, one end of the compressor is connected to the second end of the plate exchanger, and the other end of the compressor is connected to one end of the condenser; in the independent cooling mode and the mixed water operation mode, the compressor is started, and the refrigerant circulates in a closed loop. The compressor increases the pressure and temperature of the refrigerant, so that it releases heat in the condenser, and then enters the evaporator after being regulated by the EEV, absorbs the heat in the coolant, and reduces the supply temperature.

[0088] EEV, one end of EEV is connected to the other end of the condenser, the other end of EEV is connected to the third end of the plate changer, the fourth end of the plate changer is connected to one end of the battery circulating water pump, and the other end of the battery circulating water pump is connected to the battery return port. EEV is adjusted according to the suction superheat of the compressor to ensure that the refrigerant is in an appropriate superheat state before entering the compressor, optimize the working efficiency of the compressor, and prevent the occurrence of liquid hammer.

[0089] The PCS and battery liquid cooling control system also includes an on-off electric ball valve, an adjusting electric ball valve and a fan; one end of the on-off electric ball valve is connected to the side of the battery circulating water pump close to the plate changer, and the other end of the on-off electric ball valve is connected to the side of the PCS circulating water pump close to the water cooler; the on-off electric ball valve is used to control whether the water cooled by the water cooler flows into the battery circulating water pump; for example, when only the PCS side is cooled, the on-off electric ball valve is closed to prevent the coolant from flowing into the battery side; in the mixed water operation mode, the on-off electric ball valve is opened to allow part of the coolant to flow into the battery side.

[0090] One end of the regulating electric ball valve is connected to the battery liquid return port, and the other end of the regulating electric ball valve is connected to the PCS liquid return port; the regulating electric ball valve is used to adjust the liquid return ratio of the battery liquid return port and the PCS liquid return port; for example, in the mixed water operation mode, the regulating electric ball valve can adjust the coolant distribution on the battery side and the PCS side according to actual needs to optimize the cooling effect.

[0091] The fan is used to cool the condenser, and the fan speed can be adjusted according to actual needs to maintain the optimal exhaust saturation temperature and ensure that the compressor operates within a safe operating temperature range.

[0092] like Figure 7-9 As shown, Figure 7 for Figure 6 Schematic diagram of water flow in full free cooling operation mode; Figure 8 for Figure 6 Schematic diagram of water flow in independent cooling mode; Fig. 9 for Figure 6 Schematic diagram of water flow in mixed water operation mode.

[0093] Full free cooling operation mode: Cooling water on the battery side flows into port 1, then flows out from port 2 to merge with cooling water on the PCS side, and then flows into the water cooler; it is diverted through the on-off electric ball valve, with one part flowing to the PCS circulating water pump and the other part flowing to the battery circulating water pump. At this time, the regulating electric ball valve does not work.

[0094] I will not go into details here Figure 8 and Fig. 9 Schematic diagram of water flow, the water flow direction can be seen from Figure 8 and Fig. 9 Obtained without a doubt.

[0095] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A PCS and battery liquid cooling control method, characterized in that: include: Obtain the temperatures of the PCS side and the battery side, and determine whether the battery side needs to be cooled based on a comparison result between the battery side temperature and a first temperature threshold; and determine whether the PCS side needs to be cooled based on a comparison result between the PCS side temperature and a second temperature threshold; If the battery side needs to be cooled, the ambient temperature is obtained; the working mode is selected based on the comparison between the ambient temperature and the third temperature threshold and the fourth temperature threshold; the third temperature threshold is less than the fourth temperature threshold; if the ambient temperature is less than the third temperature threshold, the full free cooling operation mode is selected; if the ambient temperature is greater than the third temperature threshold and less than the fourth temperature threshold, the independent cooling mode is selected; if the ambient temperature is greater than the fourth temperature threshold, the mixed water operation mode is selected; If the PCS side needs to be cooled, only the PCS side is cooled in free cooling mode.

2. The PCS and battery liquid cooling control method according to claim 1, characterized in that: The full free cold operation mode comprises the following steps: The electric three-way valve controls the connection between port 1 and port 2; The fan starts to lower the temperature of the liquid supply on the battery side; The battery side water pump and the PCS side water pump are turned on until the battery side temperature is lower than the first temperature threshold.

3. The PCS and battery liquid cooling control method according to claim 1, characterized in that: The independent cooling mode comprises the following steps: The electric three-way valve controls the connection between port 1 and port 3; Compressor startup controls the liquid supply temperature; compressor suction superheat is controlled based on EEV, and compressor exhaust saturation temperature is controlled based on the fan; The battery side water pump and the PCS side water pump are turned on until the battery side temperature is lower than the first temperature threshold.

4. The PCS and battery liquid cooling control method according to claim 1, characterized in that: The mixed water operation mode comprises the following steps: The electric three-way valve controls the connection between port 1 and port 3; Compressor startup controls the liquid supply temperature; compressor suction superheat is controlled based on EEV, and compressor exhaust saturation temperature is controlled based on the fan; The battery side water pump and the PCS side water pump are turned on, and the electric ball valve is opened to control the PCS side liquid supply temperature until the battery side temperature is lower than the first temperature threshold.

5. The PCS and battery liquid cooling control method according to claim 1, characterized in that: The cooling of only the PCS side in the free cooling operation mode comprises the following steps: The electric three-way valve controls the connection between port 1 and port 3; The fan starts to control the liquid supply temperature on the PCS side, and the fan can only run at the minimum speed; The battery side water pump and the PCS side water pump are turned on until the PCS side temperature is lower than the second temperature threshold.

6. The PCS and battery liquid cooling control method according to claim 3 or 4, characterized in that: The compressor and the EEV are both controlled by PID; the control unit obtains the liquid supply temperature and then adjusts the working power of the compressor; the control unit obtains the suction superheat of the compressor and adjusts the valve opening of the EEV.

7. The PCS and battery liquid cooling control method according to any one of claims 1 to 5, characterized in that: It also includes a pressure sensor to obtain water pressure, and if the water pressure is less than a preset pressure value, the liquid replenishing pump is controlled to replenish liquid.

8. The PCS and battery liquid cooling control method according to claim 7, characterized in that: The PCS and battery liquid cooling control method also includes a heating mode; the heating mode is implemented based on a PTC thermistor.

9. A PCS and battery liquid cooling control system, which can be applied to the PCS and battery liquid cooling control method as described in any one of claims 1 to 8, characterized in that: include: An electric three-way valve, wherein port 1 of the electric three-way valve is connected to the battery liquid inlet, port 2 of the electric three-way valve is connected to the PCS liquid inlet, and port 3 of the electric three-way valve is connected to the first end of the plate exchanger; A water cooler, one end of which is connected to the PCS liquid inlet, the other end of which is connected to one end of the PCS circulating water pump, and the other end of which is connected to the PCS liquid return port; A compressor, one end of the compressor is connected to the second end of the plate exchanger, and the other end of the compressor is connected to one end of the condenser; EEV, one end of the EEV is connected to the other end of the condenser, the other end of the EEV is connected to the third end of the plate changer, the fourth end of the plate changer is connected to one end of the battery circulating water pump, and the other end of the battery circulating water pump is connected to the battery liquid return port.

10. The PCS and battery liquid cooling control system according to claim 9, characterized in that: It also includes an on-off electric ball valve, an adjusting electric ball valve and a fan; one end of the on-off electric ball valve is connected to the side of the battery circulating water pump close to the plate changer, and the other end of the on-off electric ball valve is connected to the side of the PCS circulating water pump close to the water cooler; the on-off electric ball valve is used to control whether the water cooled by the water cooler flows into the battery circulating water pump; one end of the adjusting electric ball valve is connected to the battery liquid return port, and the other end of the adjusting electric ball valve is connected to the PCS liquid return port; the adjusting electric ball valve is used to adjust the liquid return ratio of the battery liquid return port and the PCS liquid return port; the fan is used to cool the condenser.

Images