Temperature control method and system for power equipment

Abstract

The embodiment of the invention relates to the technical field of equipment heat dissipation, and discloses a temperature control method and system for power equipment. The power equipment is connected to the liquid cooling heat dissipation loop in series, and a temperature sensor is connected to an inlet of the power equipment in series and used for monitoring the temperature of cooling liquid at the inlet; the liquid cooling heat dissipation loop, the heat exchange heat dissipation loop and the refrigeration heat dissipation loop are connected in parallel to the power equipment through at least one multi-way valve; the method comprises the steps that a temperature threshold value is set based on the working condition of the power equipment; on the basis of the comparison result of the cooling liquid temperature and the temperature threshold value, a circulation path of cooling liquid is selected through the multi-way valve; wherein the circulation path comprises a liquid cooling heat dissipation loop, a heat exchange heat dissipation loop or a refrigeration heat dissipation loop, and any combination thereof. The system can select the loop or the loop combination meeting the current heat dissipation requirement according to the current cooling liquid state.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of device heat dissipation, in particular to a temperature control method and system of power equipment. BACKGROUND

[0002] In the power system, during the operation of the power equipment, part of the electric energy is actively or passively converted into heat. The existing technology usually dissipates heat through a heat exchange cooling system or a refrigeration cooling system. The heat exchange cooling system carries away the heat generated by the equipment through the flow of cooling liquid inside or on the surface of the equipment, and then releases the heat to the external environment through an air-water heat exchanger. The refrigeration cooling system uses a compressor, a condenser, an evaporator and an expansion valve to absorb the heat of the equipment in the evaporation process of the refrigerant, so as to cool the equipment.

[0003] In actual application, the existing heat exchange cooling system depends on the ambient temperature, and the heat dissipation efficiency decreases significantly when the ambient temperature rises. Although the refrigeration cooling system can maintain high-efficiency heat dissipation, it is accompanied by high energy consumption and high operating cost. More importantly, the two systems run independently and cannot be flexibly switched according to actual needs, resulting in energy consumption and resource waste. SUMMARY

[0004] The purpose of the embodiment of the present application is to provide a temperature control method and system of power equipment, so as to solve the problem that the heat exchange cooling system and the refrigeration cooling system run independently and cannot be flexibly switched according to actual needs, resulting in energy consumption and resource waste.

[0005] In order to solve the above technical problems, the embodiment of the present application provides a temperature control method of power equipment, the power equipment is connected in series on a liquid cooling heat dissipation circuit, a temperature sensor is connected in series at the inlet of the power equipment, and the temperature sensor is used to monitor the cooling liquid temperature at the inlet; the liquid cooling heat dissipation circuit, a heat exchange cooling circuit and a refrigeration cooling circuit are connected in parallel to the power equipment through at least one multi-way valve; the method comprises the following steps: setting a temperature threshold value based on the working condition of the power equipment; selecting a flow path of the cooling liquid through the multi-way valve based on the comparison result of the cooling liquid temperature and the temperature threshold value; wherein the flow path comprises the liquid cooling heat dissipation circuit, the heat exchange cooling circuit or the refrigeration cooling circuit, and any combination thereof.

[0006] The embodiment of the present application also provides a temperature control system of an electric power device, wherein the electric power device is connected in series to a liquid cooling heat dissipation loop, a temperature sensor is connected in series to an inlet of the electric power device, and the temperature sensor is used for monitoring a cooling liquid temperature at the inlet; the liquid cooling heat dissipation loop, a heat exchange heat dissipation loop and a refrigeration heat dissipation loop are connected in parallel to the electric power device through at least one multi-way valve; the electric power device is electrically connected to the temperature sensor and the multi-way valve; the electric power device is used for setting a temperature threshold based on a working condition of the electric power device, and is used for selecting a flow path of the cooling liquid through the multi-way valve based on a comparison result of the cooling liquid temperature and the temperature threshold; wherein the flow path comprises the liquid cooling heat dissipation loop, the heat exchange heat dissipation loop or the refrigeration heat dissipation loop, and any combination thereof.

[0007] In the embodiment of the present application, the electric power device is connected in series to the liquid cooling heat dissipation loop, the temperature sensor is arranged at the inlet of the liquid cooling heat dissipation loop, and the temperature sensor is used for acquiring the cooling liquid temperature before entering the electric power device; the liquid cooling heat dissipation loop, the heat exchange heat dissipation loop and the refrigeration heat dissipation loop are connected in parallel to the electric power device, and are connected through at least one multi-way valve, so that the flow path of the cooling liquid can be controlled based on the at least one multi-way valve, and the system with low, medium and high heat dissipation levels is provided for the cooling liquid. In the specific implementation, the temperature threshold is preset according to the working condition of the electric power device, the appropriate temperature threshold is set based on the change of the working condition of the electric power device, so as to meet the heat dissipation requirement under different working conditions; then, the cooling liquid temperature at the inlet acquired by the temperature sensor is compared with the threshold, and the multi-way valve is driven to switch the flow path of the cooling liquid, so that the cooling liquid can be switched between the three loops and the combinations thereof, and the system can select the loop or the loop combination meeting the current heat dissipation requirement according to the current cooling liquid state. Based on this, the system can increase the heat dissipation capacity when the heat dissipation requirement is improved, and can only keep the low-consumption loop when the requirement is reduced, so that the temperature of the electric power device is kept in the safe interval, and the unnecessary operation of the heat exchange or refrigeration system is avoided, and the precise temperature control and energy efficiency optimization are realized.

[0008] In addition, the method further comprises: controlling the flow of the cooling liquid on the flow path based on the temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result, so that the flow of the cooling liquid on each flow path can be dynamically adjusted according to the temperature difference between the cooling liquid temperature and the temperature threshold on the basis of the control of the flow path of the cooling liquid. The flow adjustment based on the temperature difference not only accurately matches the heat dissipation capacity with the cooling liquid heat dissipation pressure, but also further optimizes the energy consumption, avoids the insufficient extensive control caused by the single switching loop, and thus realizes the higher energy efficiency utilization rate while ensuring the stable temperature of the device.

[0009] In addition, the temperature threshold includes a first temperature threshold and a second temperature threshold; the first temperature threshold is less than the second temperature threshold; the flow path of the cooling liquid and the flow of the cooling liquid in the flow path are selected and controlled in the following manner: if the cooling liquid temperature is less than or equal to the first temperature threshold, the multi-way valve is controlled to close the heat exchange cooling loop and the refrigeration cooling loop, and the flow of the cooling liquid is adjusted based on the temperature difference between the cooling liquid temperature and the first temperature threshold; if the cooling liquid temperature is greater than or equal to the second temperature threshold, the multi-way valve is controlled to at least open the refrigeration cooling loop, and the flow of the cooling liquid in the heat exchange cooling loop and the liquid cooling loop is adjusted based on the temperature difference between the cooling liquid temperature and the second temperature threshold. In the above method, when the cooling liquid temperature does not exceed the first temperature threshold, the heat exchange cooling loop and the refrigeration cooling loop are completely closed, and the flow is adjusted in the liquid cooling loop according to the temperature difference to meet the basic cooling demand in the low load or low ambient temperature condition; when the cooling liquid temperature reaches or exceeds the second temperature threshold, at least the refrigeration cooling loop is opened in parallel, and the flow is distributed between the heat exchange loop and the liquid cooling loop according to the temperature difference to meet the enhanced cooling demand in the high load or high ambient temperature condition. This linkage control of the hierarchical threshold and the loop and the flow can minimize energy consumption and system load by first switching the loop / loop combination and then fine-tuning the flow of each loop, thereby realizing more efficient and reliable temperature management of the power equipment.

[0010] In addition, the multi-way valve is also used to adjust the flow of the cooling liquid; the flow of the cooling liquid in the flow path is controlled based on the temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result, including: the flow of the cooling liquid in the flow path is controlled by the multi-way valve based on the temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result. Therefore, by expanding the function of the multi-way valve to flow adjustment, the multi-way valve can also distribute the flow rate of the cooling liquid according to the temperature difference while switching the loop, realizing unified scheduling and flow limiting of the liquid cooling, heat exchange and refrigeration loops. In addition, this design simplifies the system structure, reduces the need for additional valves or flow control elements, integrates the opening of the cooling channel and the flow adjustment, ensures that the temperature control accuracy is met, further reduces the complexity and energy consumption of the equipment, and improves the response speed and reliability of the temperature management.

[0011] In addition, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit each include a flow regulating valve; and the method of controlling the flow of the cooling liquid in the flow path based on the temperature difference between the cooling liquid temperature and the temperature threshold value and the comparison result includes: controlling the flow of the cooling liquid in the flow path by the flow regulating valve based on the temperature difference between the cooling liquid temperature and the temperature threshold value and the comparison result. Thus, by respectively arranging the flow regulating valves on the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit and driving the valves based on the temperature difference, more precise flow control is achieved.

[0012] In addition, the method is applied to the power equipment; and the power equipment is electrically connected to the temperature sensor and the multi-way valve. Compared with the prior art of switching the circuit by the control body on the refrigeration heat dissipation circuit and switching the circuit by the external host computer, the structure takes the power equipment body as the execution body of the method, which can more conveniently and quickly respond to the working condition change and achieve rapid and accurate temperature control. BRIEF DESCRIPTION OF DRAWINGS

[0013] One or more embodiments are illustrated by way of example in the figures that are part of this disclosure and which are illustrative, but not restrictive, of the embodiments, wherein elements having the same reference number designates like elements throughout the various figures, and wherein the figures do not necessarily bear a proportional relationship to each other.

[0014] Figure 1 is a structure diagram of a heat dissipation circuit with an electronic four-way valve involved in a temperature control method of power equipment according to an embodiment of the present application;

[0015] Figure 2 is a structure diagram of a heat dissipation circuit with an electronic three-way valve involved in a temperature control method of power equipment according to an embodiment of the present application;

[0016] Figure 3 is a structure diagram of a heat dissipation circuit with a flow control valve involved in a temperature control method of power equipment according to an embodiment of the present application;

[0017] Figure 4 is a first flowchart of a temperature control method of power equipment according to an embodiment of the present application;

[0018] Figure 5 is a second flowchart of a temperature control method of power equipment according to an embodiment of the present application;

[0019] Figure 6 is a flowchart of a method of implementing circuit switching and flow control in a temperature control method of power equipment according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] In modern power systems, power electronic devices such as converters, energy storage cells, etc. have become the core components of new energy access, smart grid and industrial automation. During the operation of these devices at high power and for a long time, part of the electrical energy is converted into a large amount of heat. If the heat is not dissipated in time or sufficiently, not only will the device temperature rise, the efficiency will decrease, but also the over-temperature protection will be triggered, the life of the components will be shortened, and even the system will be shut down or malfunction, which will seriously affect the reliability and safety of the power system.

[0021] Currently, the common heat dissipation methods in industrial sites mainly include two types:

[0022] 1. Heat exchange cooling system: The cooling liquid is introduced into the device interior or attached to the heat exchange pipeline through a liquid cooling circuit, and the heat is taken away by the flow of the cooling liquid, and then the heat is released to the environment through an air-water heat exchanger. This method has simple structure and low energy consumption.

[0023] 2. Refrigeration cooling system: The refrigerant circulates between the compressor, condenser, expansion valve and evaporator, etc. Through the refrigeration cycle of evaporation heat absorption and condensation heat release, the cooling liquid is deeply cooled, so that it can still maintain high heat dissipation efficiency under high ambient temperature.

[0024] However, these two solutions have their own limitations:

[0025] 1. When the temperature difference between the environment and the cooling liquid decreases, the heat exchange capacity of the liquid cooling system will decrease significantly, making it difficult to meet the heat dissipation requirements under high temperature or heavy load conditions.

[0026] 2. Although the refrigeration system can maintain high efficiency of heat dissipation, it is accompanied by the long-term opening of high-energy-consuming components such as compressors, resulting in a sharp increase in energy consumption and rising operation and maintenance costs.

[0027] 3. More importantly, these two systems usually run independently in most applications, and cannot be cooperatively controlled according to the actual situation, which can easily lead to unnecessary energy consumption and resource waste, further increasing the operating cost.

[0028] Therefore, there is an urgent need for a temperature control solution that can sense the heat dissipation requirements in real time according to the load of the device itself and the external environment temperature, and can flexibly call different heat dissipation systems, and can seamlessly switch and cooperate between the two or multiple combinations, so as to ensure the stable and safe operation of the power device while achieving the dual optimization of energy consumption and operating cost.

[0029] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. However, those skilled in the art can understand that, in the embodiments of the present application, many technical details are presented in order to make the readers better understand the present application. However, the technical solutions claimed by the present application can be implemented even if there are no such technical details and various changes and modifications based on the following embodiments. The division of the following embodiments is for the convenience of description, and should not constitute any limitation on the specific implementation modes of the present application, and the embodiments can be combined and referenced with each other on the premise of not contradicting.

[0030] An embodiment of the present application relates to a temperature control method of a power device, the execution subject of which is a power device to be cooled, such as a battery cell with a management system, a converter, a rectifier or an inverter equipped with an embedded controller, etc., which has a control unit built-in. In some cases, the execution subject can also be a device other than the power device to be cooled, such as a smart power distribution cabinet with a microcontroller, a digital signal processor or a field programmable gate array; in addition, it can also be applied to a PLC, a DCS or a host computer monitoring terminal with control capability. The execution subject collects the signal of a temperature sensor through its internal control unit, and drives a multi-way valve to realize switching and flow regulation of each cooling circuit, so as to complete accurate control of the temperature of the power device. In the embodiment of the present application, the power device is connected in series on a liquid cooling cooling circuit, a temperature sensor is connected in series at the inlet of the power device, and is used to monitor the cooling liquid temperature at the inlet; the liquid cooling cooling circuit, the heat exchange cooling circuit and the refrigeration cooling circuit are connected in parallel to the power device through at least one multi-way valve; the method comprises: setting a temperature threshold based on the working condition of the power device; selecting the flow path of the cooling liquid through the multi-way valve based on the comparison result of the cooling liquid temperature and the temperature threshold; wherein the flow path comprises the liquid cooling cooling circuit, the heat exchange cooling circuit or the refrigeration cooling circuit, and any combination thereof. In the embodiment of the present application, the power device is connected in series on the liquid cooling cooling circuit, the temperature sensor is arranged at the inlet of the liquid cooling cooling circuit, and the temperature of the cooling liquid before entering the power device can be obtained through the temperature sensor; the liquid cooling cooling circuit, the heat exchange cooling circuit and the refrigeration cooling circuit are connected in parallel to the power device, and are connected by at least one multi-way valve, so that the flow path of the cooling liquid can be controlled based on the at least one multi-way valve, and a system providing low, medium and high cooling levels for the cooling liquid can be provided. In a specific implementation, the temperature threshold is preset according to the working condition of the power device, and the appropriate temperature threshold can be set based on the change of the working condition of the power device to meet the cooling demand under different working conditions; then, the cooling liquid temperature at the inlet obtained by the temperature sensor is compared with the threshold, and the multi-way valve is driven to switch the flow path of the cooling liquid, so that the cooling liquid can be switched between the three circuits and their combinations, and the system can select the circuit or circuit combination meeting the current cooling demand according to the current cooling liquid state. Based on this, the system can increase the cooling capacity when the cooling demand increases, and only keep the low-consumption circuit when the demand decreases, so that the temperature of the power device can be kept in the safe interval, and the unnecessary operation of the heat exchange or refrigeration system is avoided, thereby realizing accurate temperature control and energy efficiency optimization.

[0031] In the embodiment of the present application, the power device is connected in series on a liquid cooling cooling circuit, a temperature sensor is connected in series at the inlet of the power device, and is used to monitor the cooling liquid temperature at the inlet; the liquid cooling cooling circuit, the heat exchange cooling circuit and the refrigeration cooling circuit are connected in parallel to the power device through at least one multi-way valve.

[0032] In the present embodiment, the configuration and function of each heat dissipation circuit are as follows: the liquid cooling heat dissipation circuit is only composed of passive components such as pipelines, circulating pumps, liquid storage tanks, and does not contain any active heat dissipation device. When the cooling liquid flows in the device or on the surface, it relies on the temperature difference between itself, the pipe wall and the ambient air to achieve natural cooling through convection and radiation, which has extremely low energy consumption but limited heat dissipation capacity, and is suitable for low load or low ambient temperature conditions. The air-water heat exchanger is arranged on the heat exchange heat dissipation circuit, and when the cooling liquid passes through the heat exchanger, it exchanges heat with the ambient air or water system, and releases heat to the external environment, thereby achieving moderate active heat dissipation. The circuit can improve the heat exchange efficiency through auxiliary components such as fans or water pumps, and only needs to open the corresponding multi-way valve channel when switching, without the need to start the compressor refrigeration system additionally. The refrigeration heat dissipation circuit is provided with an evaporator, and the evaporator and the compressor, condenser and expansion valve are separately constructed into a refrigeration system. When the cooling liquid flows through the evaporator, the refrigerant absorbs the heat energy of the liquid to evaporate; then it is compressed by the compressor, releases heat in the condenser and liquefies, and finally returns to the evaporator through the expansion valve to complete a refrigeration cycle. The circuit can deeply cool the cooling liquid, and still maintains excellent heat dissipation effect under high ambient temperature or high power density conditions, but consumes more energy accordingly.

[0033] Among them, the above-mentioned liquid cooling heat dissipation circuit does not have an active heat dissipation device, and only through the flow of the cooling liquid in the circuit, the natural cooling of the cooling liquid is realized. The above-mentioned heat exchange heat dissipation circuit is provided with an air-water heat exchanger, which can release the heat of the cooling liquid to the external environment through the heat exchanger to achieve moderate active heat dissipation. The above-mentioned refrigeration heat dissipation circuit is provided with an evaporator containing refrigerant, which realizes deep cooling of the cooling liquid through the refrigeration cycle of evaporative heat absorption, condensation heat release between the compressor, condenser, expansion valve and evaporator, thereby maintaining high heat dissipation efficiency under high ambient temperature.

[0034] It should be noted that the method involved in the present embodiment is applied to the power device; the power device is electrically connected to the temperature sensor and the multi-way valve. Specifically, the power device can be electrically connected and communicated with the temperature sensor and the multi-way valve through an electrical connection line such as a CAN bus or a Modbus protocol. Compared with the prior art of switching the circuit through the control body on the refrigeration heat dissipation circuit and switching the circuit through the external upper computer, the present structure takes the power device body as the execution subject of the method, which can more conveniently and quickly respond to the working condition change, and realize rapid and accurate temperature control.

[0035] Optionally, the power device mentioned in the present embodiment is a converter or an electric core. That is, the temperature control method of the present embodiment can be applied to PCS and other converters, and can also directly act on battery monomers or battery modules.

[0036] In this embodiment of the invention, the flow path of the coolant needs to be switched using the aforementioned multi-way valve to achieve different cooling effects on the power equipment. Optionally, to facilitate rapid switching and precise control of different heat dissipation circuits, the following two types of multi-way valves can be selected: one electronic four-way valve, or two electronic three-way valves.

[0037] In the first case mentioned above, such as Figure 1 The aforementioned multi-way valve is an electronic four-way valve; the liquid cooling circuit, heat exchange circuit, and refrigeration circuit are connected in parallel to the power equipment via the electronic four-way valve. Specifically, in the structure of the electronic four-way valve, the valve body integrates four ports, corresponding to the inlet and outlet of the liquid cooling circuit, the inlet and outlet of the heat exchange circuit, and the inlet and outlet of the refrigeration circuit, respectively. This electronic four-way valve can achieve one-button or combined switching of the three circuits under the action of a control signal. A motor drive unit is integrated on the valve body shell; the control unit only needs to send a control command, and the four-way valve can accurately complete circuit switching, flow control, and report the current valve position and flow status in real time.

[0038] In the second case mentioned above, such as Figure 2 The system comprises two multi-way valves, both being electronic three-way valves. The liquid cooling circuit and the heat exchange circuit are connected in parallel to the power equipment via a first electronic three-way valve. The liquid cooling circuit and the refrigeration circuit are also connected in parallel to the power equipment via a second electronic three-way valve. Specifically, in the dual electronic three-way valve structure, the first and second electronic three-way valves are independently controlled, respectively responsible for switching between the liquid cooling circuit and the heat exchange circuit, and between the liquid cooling circuit and the refrigeration circuit. One set of channels of the first electronic three-way valve is connected in series with the liquid cooling circuit, and the other set is connected in series with the heat exchange circuit. The second electronic three-way valve has one set of channels connected in series with the liquid cooling circuit, and the other set is connected in series with the refrigeration circuit. The two electronic three-way valves connect the heat exchange circuit and the refrigeration circuit in parallel to the liquid cooling circuit in this manner. The power equipment sends control commands to the two electronic three-way valves via electrical connection lines, and the two electronic three-way valves switch and combine circuits based on the controlled refrigeration. Furthermore, this solution has advantages in fault redundancy: even if one of the electronic three-way valves gets stuck, the other electronic three-way valve can still maintain the operation of either the liquid cooling circuit or the refrigeration circuit or the heat exchange circuit.

[0039] In the embodiment of the present application, the flow of the cooling liquid in the flow path needs to be controlled to achieve more precise cooling liquid temperature control, thereby achieving more precise power equipment cooling effect. Optionally, in order to finely adjust the flow of the cooling liquid in each loop, two structures can be selected: through the flow control function of the multi-way valve itself, or by adding a flow regulating valve to achieve flow control.

[0040] In the above first case, as Figure 1 The flow control can be achieved by adjusting the multi-way valve itself based on the control instruction of the power equipment. Specifically, when the flow control is performed by the multi-way valve itself, an electronic multi-way valve with a proportional valve core can be selected, and the valve core is driven by a stepper motor or a servo motor. The power equipment sends a control instruction to the multi-way valve through an electrical connection line, and the multi-way valve adjusts the flow of the cooling liquid to the corresponding loop based on the control instruction. Based on this, the advantage of one valve with multiple uses can be achieved, that is, coarse adjustment of the loop and fine adjustment of the flow.

[0041] In the above second case, as Figure 3 A flow regulating valve can be arranged on each of the heat exchange heat dissipation loop and the refrigeration heat dissipation loop. The flow regulating valve on the corresponding loop is adjusted based on the control instruction of the power equipment to achieve flow control. Specifically, an electronic expansion valve or a proportional flow dividing valve can be independently installed on the heat exchange heat dissipation loop and the refrigeration heat dissipation loop. The power equipment can send a control instruction to each flow regulating valve through an electrical connection line, and each flow regulating valve adjusts the flow of the corresponding loop. This structure can independently adjust the heat exchange heat dissipation loop and the refrigeration heat dissipation loop when the loop is switched, so that stable cooling effect can be maintained without overshoot during switching.

[0042] In the embodiment of the present application, an expansion tank is further arranged on the liquid cooling heat dissipation loop to compensate for the volume change of the cooling liquid. Specifically, the expansion tank can be preferably arranged at the highest point of the liquid cooling loop, and a certain rated volume allowance is reserved to adapt to the thermal expansion caused by temperature rise. In addition, a liquid level sensor is arranged on the inner wall of the expansion tank to monitor the liquid level in the loop in real time. When the liquid level exceeds the preset safety range, an alarm is sent to the power equipment and a liquid supplement device is started to compensate. At the same time, a safety relief valve is arranged at the top of the expansion tank to automatically release pressure when the pressure exceeds the design value, thereby ensuring the safety of the system.

[0043] In the embodiment of the present application, a circulating pump is further arranged on the liquid cooling heat dissipation loop, and the circulating pump is used to make the cooling liquid flow. When it is detected that the flow in the loop is lower than a preset threshold or the pump body temperature is abnormal, the power equipment can send a stop instruction to the circulating pump through an electrical connection line, so that the power equipment can obtain stable and reliable cooling liquid circulation in any case.

[0044] The following will specifically describe the implementation details of the temperature control method of the power equipment of the embodiment of the present application. The following implementation details are provided for the convenience of understanding, and are not essential for implementing the present solution.

[0045] As shown in Figure 4 The embodiment of the present application includes steps 110 and 130, and the details are as follows:

[0046] In step 110, a temperature threshold is set based on the working condition of the power equipment.

[0047] Specifically, according to the current operating condition of the power equipment (such as output power, ambient temperature, load fluctuation, etc.), the control unit in the power equipment refers to the pre-calibrated working condition-temperature mapping table to set the temperature threshold. The mapping table can be obtained through offline calibration experiments, or can be optimized online based on historical operation data of the equipment, so that the temperature threshold can meet the safety margin of the equipment, and frequent switching is not triggered due to being too high or too low. At the same time, a hysteresis interval can be added in the threshold setting to avoid system control jitter caused by slight fluctuations in temperature, thereby improving the stability and reliability of the heat dissipation system.

[0048] Optionally, the temperature threshold can also be updated in real time according to the current working condition of the power equipment to achieve dynamic adjustment of the temperature threshold, that is, dynamic adjustment of the cooling liquid processing logic.

[0049] In step 120, based on the comparison result of the cooling liquid temperature and the temperature threshold, the flow path of the cooling liquid is selected through the multi-way valve; wherein the flow path includes a liquid cooling heat dissipation loop, a heat exchange heat dissipation loop or a refrigeration heat dissipation loop, and any combination thereof.

[0050] Step 130, based on the temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result, control the flow of the cooling liquid in the flow path.

[0051] In the above step 130, based on the control of the cooling liquid flow path, the flow of the cooling liquid in each flow path can be dynamically adjusted according to the temperature difference between the cooling liquid temperature and the temperature threshold. This temperature difference-based flow adjustment not only accurately matches the heat dissipation capacity with the cooling liquid heat dissipation pressure, but also further optimizes the energy consumption, avoids the deficiency of extensive control caused by single switching loop, thereby ensuring the stability of the equipment temperature while achieving higher energy efficiency.

[0052] It should be noted that in the embodiments of the present application, steps 110 and 120 in the above method constitute a basic cooling liquid flow path switching function: only by setting a temperature threshold and comparing the temperature, automatic switching between the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit can be realized, and the heat dissipation demand under general working conditions can be met. When there is a higher requirement for temperature control accuracy and response speed, step 130 can be further executed to finely adjust the flow of the cooling liquid, and the synergy of flow path switching and flow control is realized to maintain the device temperature in the target range in a fast and energy-saving manner. Users can flexibly set to execute only steps 110 to 120 or execute steps 110 to 130 at the same time according to the device operating conditions and control requirements, so as to balance the system complexity, response speed and energy consumption.

[0053] As described above, in an optional embodiment, when only the control of the flow path of the cooling liquid needs to be realized, steps 120 can be used to achieve the purpose. At this time, the temperature threshold can include a first temperature threshold and a second temperature threshold; the first temperature threshold is less than the second temperature threshold. As Figure 5 Step 120 includes steps 210 to 230, which are as follows:

[0054] In step 210, if the cooling liquid temperature is less than or equal to the first temperature threshold, the multi-way valve is controlled to make the cooling liquid pass through only the liquid cooling heat dissipation circuit. Therefore, this mode can meet the basic heat dissipation demand when the device load is low or the environmental temperature is low, while the energy consumption of the heat exchanger and the refrigeration unit is maximally saved.

[0055] In step 220, if the cooling liquid temperature is greater than the first temperature threshold and less than the second temperature threshold, the multi-way valve is controlled to make the cooling liquid pass through the liquid cooling heat dissipation circuit and the heat exchange heat dissipation circuit at the same time. Therefore, this mode makes the cooling liquid carry the heat inside the device and also releases part of the heat to the external environment through the air-water heat exchanger after passing through the power device.

[0056] In step 230, if the cooling liquid temperature is greater than or equal to the second temperature threshold, the multi-way valve is controlled to make the cooling liquid pass through the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit at the same time. Therefore, this mode can start the refrigeration unit to deeply cool the cooling liquid after heat exchange, so as to meet the heat dissipation demand under high load or extreme environment.

[0057] As mentioned above, in another optional embodiment, i.e. when the cooperative control of the flow path and flow rate of the cooling liquid needs to be achieved, the steps 120 to 130 are needed to be performed. At this time, the temperature threshold includes a first temperature threshold and a second temperature threshold; the first temperature threshold is less than the second temperature threshold. As Figure 6 , the steps 120 and 130 include steps 310 to 320, which are as follows:

[0058] In step 310, if the cooling liquid temperature is less than or equal to the first temperature threshold, the multi-way valve is controlled to close the heat exchange cooling loop and the refrigeration cooling loop, and the flow rate of the cooling liquid is adjusted based on the temperature difference between the cooling liquid temperature and the first temperature threshold.

[0059] In step 320, if the cooling liquid temperature is greater than or equal to the second temperature threshold, the multi-way valve is controlled to at least open the refrigeration cooling loop, and the flow rate of the cooling liquid in the heat exchange cooling loop and the liquid cooling loop is adjusted based on the temperature difference between the cooling liquid temperature and the second temperature threshold.

[0060] Through the above steps 310 to 320, when the cooling liquid temperature does not exceed the first temperature threshold, the heat exchange cooling loop and the refrigeration cooling loop can be completely closed, and the flow rate in the liquid cooling loop is adjusted according to the temperature difference to meet the basic cooling demand in the low load or low ambient temperature condition; when the cooling liquid temperature reaches or exceeds the second temperature threshold, at least the refrigeration cooling loop is opened in parallel, and the flow rate is distributed between the heat exchange loop and the liquid cooling loop according to the temperature difference to meet the enhanced cooling demand in the high load or high ambient temperature condition. This linkage control of the hierarchical threshold and the loop and flow rate, by first switching the loop / loop combination and then fine-tuning the flow rate of each loop, can minimize energy consumption and system load, thereby achieving more efficient and reliable temperature management of the power equipment.

[0061] Optionally, after the above steps 310 to 320, the temperature threshold further includes a third temperature threshold, and the third temperature threshold is less than the first temperature threshold. At this time, as Figure 6 , step 330 is further included, and when the cooling liquid temperature is less than the third temperature threshold, the circulating pump is closed. In this way, it can be avoided that the equipment is over-cooled or the temperature difference is too large due to continuous circulation in extreme conditions (such as extremely low ambient temperature or sudden cooling of the cooling liquid after the equipment is shut down), which may cause thermal stress or temperature out of control. Through the hierarchical linkage of the existing three-level threshold (third threshold < first threshold < second threshold) and the loop, flow rate, and pump stop, not only the cooling efficiency and energy consumption can be balanced, but also the equipment can be automatically protected in a special temperature range, thereby improving the reliability and safety of the overall system.

[0062] In the embodiment of the present application, when adjusting the flow of the cooling liquid in step 130, in order to finely adjust the flow of the cooling liquid in each circuit, two structures can be selected: through the flow control function of the multi-way valve itself, or by adding a flow regulating valve to achieve flow control.

[0063] As shown above, in the first structure, i.e. through the flow control function of the multi-way valve itself, step 130 is specifically implemented as: based on the temperature difference between the cooling liquid temperature and the temperature threshold value and the comparison result, the flow of the cooling liquid in the flow path is controlled through the multi-way valve. Thus, by extending the function of the multi-way valve to flow regulation, the multi-way valve can not only switch the circuit, but also distribute the cooling liquid flow rate according to the temperature difference, realizing the unified scheduling and flow limiting of the liquid cooling, heat exchange and refrigeration circuits. In addition, this design simplifies the system structure, reduces the need for additional valves or flow control elements, integrates the opening of the heat dissipation channel and flow regulation, ensures that the temperature control accuracy is met, further reduces the complexity and energy consumption of the equipment, and improves the response speed and reliability of temperature management.

[0064] As shown above, in the second structure, i.e. through the addition of a flow regulating valve to achieve flow control, step 130 is specifically implemented as: based on the temperature difference between the cooling liquid temperature and the temperature threshold value and the comparison result, the flow of the cooling liquid in the flow path is controlled through the flow regulating valve. Thus, by setting flow regulating valves on the heat exchange and refrigeration cooling circuits respectively, and driving these valves based on the temperature difference, more precise flow control is achieved.

[0065] In the embodiment of the present application, the power equipment is connected in series on the liquid cooling heat dissipation circuit, the temperature sensor is arranged at the inlet of the liquid cooling heat dissipation circuit, the temperature of the cooling liquid before entering the power equipment can be obtained through the temperature sensor, the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit are connected in parallel to the power equipment, and at least one multi-way valve is used to realize the connection, so that the flow path of the cooling liquid can be controlled based on the at least one multi-way valve, and the system with low, medium and high heat dissipation levels is provided for the cooling liquid. In the specific implementation, the temperature threshold value is preset according to the working condition of the power equipment, the appropriate temperature threshold value can be set based on the change of the working condition of the power equipment to meet the heat dissipation requirement in different working conditions, then the temperature of the cooling liquid at the inlet obtained by the temperature sensor is compared with the threshold value, the multi-way valve is driven to switch the flow path of the cooling liquid, the cooling liquid can be switched between the three circuits and their combinations, and the system can select the circuit or circuit combination meeting the current heat dissipation requirement according to the current state of the cooling liquid. Based on this, the system can increase the heat dissipation capacity when the heat dissipation requirement increases, and only keep the low-consumption circuit when the requirement decreases, so that the temperature of the power equipment can be kept in the safe range, and the unnecessary operation of the heat exchange or refrigeration system is avoided, thereby realizing accurate temperature control and energy efficiency optimization.

[0066] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise specifically limited.

[0067] In the description of the embodiments of the present application, the term "and / or" is only used to describe the association relationship of the associated objects, which means that there are three kinds of relationships, for example, A and / or B, which means that there are three kinds of situations that A exists, A and B exist, and B exists. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0068] The step division of the above method is only for clear description, and can be combined into one step or split into multiple steps in implementation, as long as the same logical relationship is included, which is within the protection scope of the present patent; adding insignificant modifications or introducing insignificant designs in the algorithm or flow, but not changing the core design of the algorithm and flow are within the protection scope of the present patent.

[0069] In addition, the examples mentioned in the above embodiments can be freely combined, and any combination can be understood as an embodiment. The "embodiment" or "example" appearing at various positions in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. Those skilled in the art can understand that the embodiments described herein can be combined with other embodiments.

[0070] Another embodiment of the present application relates to a temperature control system of an electric power device, wherein the electric power device is connected in series to a liquid cooling heat dissipation loop, a temperature sensor is connected in series at an inlet of the electric power device for monitoring a temperature of cooling liquid at the inlet; the liquid cooling heat dissipation loop, a heat exchange heat dissipation loop and a refrigeration heat dissipation loop are connected in parallel to the electric power device through at least one multi-way valve; the electric power device is electrically connected to the temperature sensor and the multi-way valve; the electric power device is configured to set a temperature threshold based on a working condition of the electric power device; and to select a flow path of the cooling liquid through the multi-way valve based on a comparison result of the temperature of the cooling liquid and the temperature threshold; wherein the flow path includes the liquid cooling heat dissipation loop, the heat exchange heat dissipation loop or the refrigeration heat dissipation loop, and any combination thereof.

[0071] In an optional embodiment, the temperature threshold includes a first temperature threshold and a second temperature threshold; the first temperature threshold is less than the second temperature threshold. At this time, the electric power device is configured to control the multi-way valve to make the cooling liquid pass through only the liquid cooling heat dissipation loop when the temperature of the cooling liquid is less than or equal to the first temperature threshold; and to control the multi-way valve to make the cooling liquid pass through the liquid cooling heat dissipation loop and the heat exchange heat dissipation loop at the same time when the temperature of the cooling liquid is greater than the first temperature threshold and less than the second temperature threshold; and to control the multi-way valve to make the cooling liquid pass through the liquid cooling heat dissipation loop, the heat exchange heat dissipation loop and the refrigeration heat dissipation loop at the same time when the temperature of the cooling liquid is greater than or equal to the second temperature threshold.

[0072] In the embodiments of the present application, the electric power device is further configured to control a flow rate of the cooling liquid in the flow path based on a temperature difference between the temperature of the cooling liquid and the temperature threshold and the comparison result.

[0073] In an optional embodiment, the temperature threshold comprises a first temperature threshold and a second temperature threshold; the first temperature threshold is less than the second temperature threshold; the power device selects the flow path of the cooling liquid and controls the flow of the cooling liquid in the flow path by: if the cooling liquid temperature is less than or equal to the first temperature threshold, controlling the multi-way valve to close the heat exchange cooling loop and the refrigeration cooling loop, and adjusting the flow of the cooling liquid based on the temperature difference between the cooling liquid temperature and the first temperature threshold; if the cooling liquid temperature is greater than or equal to the second temperature threshold, controlling the multi-way valve to at least open the refrigeration cooling loop, and adjusting the flow of the cooling liquid in the heat exchange cooling loop and the liquid cooling cooling loop based on the temperature difference between the cooling liquid temperature and the second temperature threshold.

[0074] Further, in the optional embodiment described above, the temperature threshold further comprises a third temperature threshold, and the third temperature threshold is less than the first temperature threshold. The liquid cooling cooling loop is further provided with a circulating pump for flowing the cooling liquid; the power device is further configured to close the circulating pump when the cooling liquid temperature is less than the third temperature threshold.

[0075] It should be noted that in the embodiments of the present application, the flow of the cooling liquid in the flow path needs to be controlled to achieve more precise cooling liquid temperature control, thereby achieving more precise power device cooling effect. Optionally, in order to finely adjust the flow of the cooling liquid in each loop, two structures can be selected: through the flow control function of the multi-way valve itself, or by adding a flow regulating valve to achieve flow control.

[0076] In an optional embodiment, the multi-way valve is further configured to adjust the flow of the cooling liquid. At this time, the power device is configured to control the flow of the cooling liquid in the flow path through the multi-way valve based on the temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result.

[0077] In an optional embodiment, the heat exchange cooling loop and the refrigeration cooling loop each comprise a flow regulating valve. At this time, the power device is configured to control the flow of the cooling liquid in the flow path through the flow regulating valve based on the temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result.

[0078] It should be noted that in the embodiments of the present application, the flow path of the cooling liquid needs to be switched through the multi-way valve described above, thereby achieving different cooling effects on the power device. Optionally, in order to facilitate the rapid switching and accurate control of different cooling loops, two forms of multi-way valves can be selected: an electronic four-way valve, or two electronic three-way valves.

[0079] In an optional embodiment, the multi-way valve is an electronic four-way valve; the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit are connected in parallel to the power device through the electronic four-way valve.

[0080] In an optional embodiment, the number of the multi-way valves is 2, and the multi-way valves are electronic three-way valves; the liquid cooling heat dissipation circuit and the heat exchange heat dissipation circuit are connected in parallel to the power device through a first electronic three-way valve; and the liquid cooling heat dissipation circuit and the refrigeration heat dissipation circuit are connected in parallel to the power device through a second electronic three-way valve.

[0081] In the embodiments of the present application, an expansion tank is further arranged on the liquid cooling heat dissipation circuit to compensate the volume change of the cooling liquid.

[0082] In the embodiments of the present application, the power device is a converter or an electric core, or other power device with a built-in control unit to be cooled.

[0083] It can be found that the present embodiment is a device embodiment corresponding to the above-mentioned method embodiments, and the present embodiment can be implemented in cooperation with the above-mentioned method embodiments. The related technical details mentioned in the above-mentioned method embodiments are still valid in the present embodiment. In order to reduce repetition, they will not be described here. Correspondingly, the related technical details mentioned in the present embodiment can also be applied in the above-mentioned method embodiments.

[0084] It is worth mentioning that each module involved in the present embodiment is a logical module. In actual application, a logical unit can be a physical unit, or a part of a physical unit, or realized in combination of multiple physical units. In addition, in order to highlight the innovative part of the present application, units not closely related to solving the technical problems proposed in the present application are not introduced in the present embodiment, but this does not mean that there are no other units in the present embodiment.

[0085] Those skilled in the art can understand that the above-mentioned embodiments are specific embodiments for implementing the present application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. A temperature control method of an electric power device, characterized by, The power device is connected in series with a liquid cooling heat dissipation circuit, a temperature sensor is connected in series with an inlet of the power device, and the temperature sensor is used to monitor a cooling liquid temperature at the inlet; the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit are connected in parallel with the power device through at least one multi-way valve; The method comprises: setting a temperature threshold based on a working condition of the power device; selecting a flow path of the cooling liquid through the multi-way valve based on a comparison result of the cooling liquid temperature and the temperature threshold; The flow path comprises the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit or the refrigeration heat dissipation circuit, or any combination thereof.

2. The temperature control method of a power device according to claim 1, characterized by, The temperature threshold comprises a first temperature threshold and a second temperature threshold; the first temperature threshold is less than the second temperature threshold; The method comprises: if the cooling liquid temperature is less than or equal to the first temperature threshold, controlling the multi-way valve to make the cooling liquid pass through only the liquid cooling heat dissipation circuit; if the cooling liquid temperature is greater than the first temperature threshold and less than the second temperature threshold, controlling the multi-way valve to make the cooling liquid pass through the liquid cooling heat dissipation circuit and the heat exchange heat dissipation circuit at the same time; if the cooling liquid temperature is greater than or equal to the second temperature threshold, controlling the multi-way valve to make the cooling liquid pass through the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit at the same time.

3. The temperature control method of a power device according to claim 1, characterized by, The method further comprises: controlling a flow rate of the cooling liquid in the flow path based on a temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result.

4. The temperature control method of a power device according to claim 3, characterized by, The temperature threshold comprises a first temperature threshold and a second temperature threshold; the first temperature threshold is less than the second temperature threshold; The method comprises: if the cooling liquid temperature is less than or equal to the first temperature threshold, controlling the multi-way valve to close the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit, and adjusting the flow rate of the cooling liquid based on a temperature difference between the cooling liquid temperature and the first temperature threshold; if the cooling liquid temperature is greater than or equal to the second temperature threshold, controlling the multi-way valve to open at least the refrigeration heat dissipation circuit, and adjusting the flow rate of the cooling liquid in the heat exchange heat dissipation circuit and the liquid cooling heat dissipation circuit based on a temperature difference between the cooling liquid temperature and the second temperature threshold.

5. The temperature control method of a power device according to claim 3, wherein The multi-way valve is further used to adjust the flow rate of the cooling liquid; The method comprises: controlling the flow rate of the cooling liquid in the flow path through the multi-way valve based on the temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result.

6. The temperature control method of a power device according to claim 3, wherein The heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit each comprise a flow rate adjusting valve; The method comprises: The flow of the cooling liquid in the flow path is controlled by the flow regulating valve based on the temperature difference between the cooling liquid temperature and the temperature threshold and the comparison result.

7. The temperature control method of a power device according to claim 4, wherein The temperature threshold further includes a third temperature threshold, which is less than the first temperature threshold; the liquid cooling heat dissipation circuit further comprises a circulating pump configured to flow the cooling liquid; and the method further comprises: When the cooling liquid temperature is less than the third temperature threshold, the circulating pump is turned off.

8. The temperature control method of the power device according to claim 1, wherein The method is applied to the power equipment; and the power equipment is electrically connected with the temperature sensor and the multi-way valve.

9. The temperature control method of the power device according to any one of claims 1 to 8, characterized by, The multi-way valve is an electronic four-way valve. The liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit are connected in parallel to the power equipment through an electronic four-way valve.

10. The temperature control method of the power device according to any one of claims 1 to 8, characterized by, The number of the multi-way valves is two, and the multi-way valves are electronic three-way valves. The liquid cooling heat dissipation circuit and the heat exchange heat dissipation circuit are connected in parallel to the power equipment through a first electronic three-way valve. The liquid cooling heat dissipation circuit and the refrigeration heat dissipation circuit are connected in parallel to the power equipment through a second electronic three-way valve.

11. The temperature control method of the power device according to any one of claims 1 to 8, characterized by, The liquid cooling heat dissipation circuit further comprises an expansion tank configured to compensate for the volume change of the cooling liquid.

12. The temperature control method of the power device according to any one of claims 1 to 8, characterized by, The power equipment is a converter or a battery cell.

13. A temperature control system for an electrical device, characterized by The power equipment is connected in series to the liquid cooling heat dissipation circuit, a temperature sensor is connected in series to an inlet of the power equipment, the temperature sensor is configured to monitor the cooling liquid temperature at the inlet, the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit and the refrigeration heat dissipation circuit are connected in parallel to the power equipment through at least one multi-way valve, and the power equipment is electrically connected with the temperature sensor and the multi-way valve. The power equipment is configured to set a temperature threshold based on the working condition of the power equipment, and to select a flow path of the cooling liquid through the multi-way valve based on the comparison result between the cooling liquid temperature and the temperature threshold; wherein the flow path includes the liquid cooling heat dissipation circuit, the heat exchange heat dissipation circuit or the refrigeration heat dissipation circuit, or any combination thereof.

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