Direct-hanging energy storage converter water cooling system and control method

Abstract

The invention discloses a direct-hanging energy storage converter water cooling system and a control method, and relates to the technical field of energy storage systems, the system comprises a water cooling unit, a water inlet solenoid valve, a water outlet solenoid valve, a water segregator and a three-phase power module; the water cooling unit is connected with the water inlet electromagnetic valve and the water outlet electromagnetic valve and used for providing cooling water for the three-phase power module. The water inlet electromagnetic valve is connected with an inlet of the water segregator and used for controlling the pressure and flow of inlet water; the water outlet electromagnetic valve is connected with the three-phase water outlet pipe and is used for controlling the pressure and flow of outlet water; an outlet pipeline of the water segregator is connected with one end of a three-phase power module, and the other end of the three-phase power module is connected with an output pipeline and is converged to be connected with a water outlet electromagnetic valve. Through flow control in the horizontal direction and the vertical direction, three-phase water pressure and water flow velocity balance is achieved, and therefore three-phase dynamic heat balance of the direct-hanging energy storage converter and heat management, closed circulation heat dissipation and high protection level of all power assemblies are achieved.

Description

Technical Field

[0001] This invention relates to the field of energy storage system technology, and in particular to a water-cooling system and control method for a direct-connected energy storage converter. Background Technology

[0002] A direct-connect energy storage converter (PCS) is a power conversion device that converts direct current (DC) to alternating current (AC) or vice versa to meet the grid's charging and discharging requirements for energy storage systems. When designing a water-cooling system for a PCS, several factors need to be considered, including system thermal management, equipment stability, efficiency, and maintenance costs.

[0003] Designing a direct-connected energy storage converter requires comprehensive consideration of heat exchange efficiency, system stability, equipment lifespan, environmental impact, safety, and ease of maintenance. Through proper design and intelligent control, the energy storage converter can be ensured to operate efficiently and stably under various conditions.

[0004] For example, Chinese patent CN114784402A provides an environmental control system for water-cooled energy storage systems, achieving integrated system composition, intelligent system control, and high-level sealing protection. It combines battery system thermal management, prefabricated compartment environmental control, and electrical equipment compartment environmental control into an integrated environmental control system. However, this system does not provide methods for horizontal and vertical flow balancing control, and therefore cannot effectively suppress uneven module operating temperatures. Uneven module operating temperatures can easily lead to problems such as the system not operating at full load and module overheating failures.

[0005] In summary, the existing technology system still lacks an effective multi-dimensional control method for adjusting flow rate and temperature, and no effective solution has yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0006] Therefore, it is necessary to provide a water-cooling system and control method for a direct-connected energy storage converter to address the aforementioned technical problems.

[0007] In a first aspect, the present invention provides a water-cooled system for a direct-connected energy storage converter, comprising: a water-cooled unit, an inlet solenoid valve, an outlet solenoid valve, a water distributor, and a three-phase power module.

[0008] The water-cooled unit is connected to the inlet solenoid valve and the outlet solenoid valve respectively, and is used to provide cooling water for the three-phase power module.

[0009] The inlet solenoid valve is connected to the inlet of the water distributor to control the pressure and flow rate of the incoming water;

[0010] The outlet solenoid valve is connected to the three-phase outlet pipe to control the outlet pressure and flow rate;

[0011] The outlet pipes of the water distributor are connected to one end of the three-phase power module, and the other end of the three-phase power module is connected to the output pipe, which is then connected to the outlet solenoid valve.

[0012] Furthermore, the three-phase power module includes three phases and several levels of independent power modules. The independent power modules located in the same phase are connected in parallel, and the number of independent power modules in each phase is the same.

[0013] Each independent power module includes a water-cooled PACK module and an energy storage converter module.

[0014] Furthermore, the water inlet of the water-cooled PACK module is connected in parallel with the water inlet of the energy storage converter module, and is connected to the outlet pipe of the water distributor through a solenoid valve. The solenoid valve is used to maintain the same water inlet flow rate for the water-cooled PACK module and the energy storage converter module.

[0015] Furthermore, the water distributor is located above the energy storage converter module and is installed horizontally. All multiple outlets of the water distributor are at the same height to maintain pressure and flow balance within the energy storage converter module.

[0016] Furthermore, both the inlet solenoid valve and the outlet solenoid valve utilize flow control formulas for flow control.

[0017] The calculation process of the flow control formula includes:

[0018] Collect the actual average temperature of the water-cooled PACK module and energy storage converter module in each independent power module, calculate the sum of the temperatures of the independent power modules of each three-phase stage, and sum the temperatures of all stages. Then calculate the average value of the summed values ​​to obtain the average temperature term.

[0019] Obtain the preset temperature setting value and subtract the average temperature value to obtain the temperature deviation;

[0020] Obtain the integral coefficient and proportional coefficient common to the inlet solenoid valve and the outlet solenoid valve. Divide the integral coefficient by the complex frequency variable to obtain the integral term and the proportional coefficient to obtain the proportional term. Calculate the sum of the integral term and the proportional term to obtain the control coefficient.

[0021] Multiplying the temperature deviation by the control coefficient yields the flow control deviation between the inlet and outlet solenoid valves, thereby enabling flow adjustment between the inlet and outlet solenoid valves.

[0022] Furthermore, the solenoid valve uses the cross-sectional area calculation formula to control the pressure and flow balance between the corresponding water-cooled PACK module and the energy storage converter module.

[0023] The calculation process for the cross-sectional area includes:

[0024] The average actual temperature of the water-cooled PACK module and energy storage converter module in any independent power module is obtained. The cumulative average actual temperature of all independent power modules in the same phase is subtracted to obtain the single-phase temperature difference. The single-phase temperature difference is then multiplied by the controller transfer function and the temperature influence factor to obtain the temperature regulation component.

[0025] Calculate the cumulative average value of liquid flow rate of all stages of solenoid valves in the phase where any independent power module is located, obtain the average flow rate value, divide it by the factor composed of the flow coefficient and the pressure difference between the two ends of the independent power module, obtain the flow rate term, multiply it by the liquid flow rate influence factor, and obtain the flow rate correction component.

[0026] The temperature regulation component and the flow correction component are added together to obtain the signal of change in flow cross-sectional area used to control the opening of the solenoid valve.

[0027] Furthermore, both the temperature influence factor and the flow rate influence factor can be automatically adjusted according to the actual operating conditions;

[0028] The automatic adjustment of the temperature influence factor based on actual operating conditions includes:

[0029] Several experimental groups were set up for all independent power modules in a single phase. The actual temperature data of the water-cooled PACK module and the energy storage converter module in each independent power module were recorded, and the deviation value between the independent power module and the actual average temperature in each experimental group was calculated.

[0030] The minimum deviation of the independent power module within a single phase is selected as the temperature influence factor.

[0031] Secondly, the present invention also provides a control method for a water-cooled system of a direct-connected energy storage converter, the control method comprising:

[0032] The cooling water in the water-cooled unit is supplied to the water distributor by the inlet solenoid valve, and the actual temperature data in the three-phase power module is monitored in real time. The flow control deviation of the inlet solenoid valve is calculated in real time using the flow control formula, so as to adjust and control the pressure and flow of the cooling water inlet in real time.

[0033] The opening degree of the solenoid valve is calculated using the cross-sectional area calculation formula, and the solenoid valves corresponding to each independent power module are controlled in real time to ensure that the water inlet flow of all water-cooled PACK modules and energy storage converter modules in the three-phase power module is consistent.

[0034] The cooling water discharged from the three-phase power module is delivered to the water-cooled unit by the outlet solenoid valve. The flow control deviation of the outlet solenoid valve is calculated in real time using the flow control formula, so as to adjust and control the pressure and flow of the cooling water outlet in real time and realize the recycling of return water.

[0035] Furthermore, the flow control deviation of the inlet solenoid valve is calculated in real time using the flow control formula, including:

[0036] Collect the actual average temperature of the water-cooled PACK module and energy storage converter module in each independent power module, calculate the sum of the temperatures of the independent power modules of each three-phase stage, and sum the temperatures of all stages. Then calculate the average value of the summed values ​​to obtain the average temperature term.

[0037] Obtain the preset temperature setting value and subtract the average temperature value to obtain the temperature deviation;

[0038] Obtain the integral coefficient and proportional coefficient of the inlet solenoid valve, divide the integral coefficient by the complex frequency variable to obtain the integral term and the proportional coefficient to obtain the proportional term, and calculate the sum of the integral term and the proportional term as the control coefficient.

[0039] Multiplying the temperature deviation by the control coefficient yields the flow control deviation of the inlet solenoid valve, thereby enabling flow adjustment of the inlet solenoid valve.

[0040] Furthermore, the calculation of the solenoid valve opening degree using the cross-sectional area calculation formula includes:

[0041] The average actual temperature of the water-cooled PACK module and energy storage converter module in any independent power module is obtained. The cumulative average actual temperature of all independent power modules in the same phase is subtracted to obtain the single-phase temperature difference. The single-phase temperature difference is then multiplied by the controller transfer function and the temperature influence factor to obtain the temperature regulation component.

[0042] Calculate the cumulative average value of liquid flow rate of all stages of solenoid valves in the phase where any independent power module is located, obtain the average flow rate value, divide it by the factor composed of the flow coefficient and the pressure difference between the two ends of the independent power module, obtain the flow rate term, multiply it by the liquid flow rate influence factor, and obtain the flow rate correction component.

[0043] The temperature regulation component and the flow correction component are added together to obtain the signal of change in flow cross-sectional area used to control the opening of the solenoid valve.

[0044] The beneficial effects of this invention are as follows: By controlling the flow rate in the horizontal and vertical directions, the three-phase water pressure and flow velocity are balanced, thereby achieving dynamic thermal balance of the three phases in the direct-connected energy storage converter and thermal management of each power component. It features closed-loop heat dissipation, high protection level, and meets the environmental adaptability requirements of the direct-connected energy storage converter. It has the advantages of simple structure and flexible method, providing an effective solution for the module balancing control of high-voltage direct-connected cascaded energy storage converters. It can be widely used in the field of water-cooled cascaded high-voltage, high-capacity power conversion. By maintaining temperature balance, it can reduce the performance degradation of equipment caused by temperature imbalance, improve system stability, and extend the service life of the entire equipment. Attached Figure Description

[0045] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0046] Figure 1 This is a system block diagram of a direct-connected energy storage converter water cooling system according to an embodiment of the present invention;

[0047] Figure 2 This is a logic execution diagram of a direct-connected energy storage converter water-cooling system according to an embodiment of the present invention;

[0048] Figure 3 This is a schematic diagram of an independent power module in a direct-connected energy storage converter water cooling system according to an embodiment of the present invention;

[0049] Figure 4 This is a flowchart of a control method for a direct-connected energy storage converter water-cooling system according to an embodiment of the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0051] Please see Figures 1-3 A direct-connected energy storage converter water cooling system is provided, including: a water-cooled unit, an inlet solenoid valve, an outlet solenoid valve, a water distributor, and a three-phase power module.

[0052] The water-cooled unit is connected to the inlet solenoid valve and the outlet solenoid valve respectively, and is used to provide cooling water for the three-phase power module.

[0053] The inlet solenoid valve is connected to the inlet of the water distributor to control the pressure and flow rate of the incoming water.

[0054] The outlet solenoid valve is connected to the three-phase outlet pipe and is used to control the outlet pressure and flow rate.

[0055] The outlet pipes of the water distributor are connected to one end of the three-phase power module, and the other end of the three-phase power module is connected to the output pipe, which is then connected to the outlet solenoid valve.

[0056] In the description of this invention, the three-phase power module includes three phases and several levels of independent power modules, the independent power modules located in the same phase are connected in parallel, and the number of independent power modules in each phase is the same; each independent power module includes a water-cooled PACK module and an energy storage converter module.

[0057] Specifically, such as Figure 1 and Figure 3 As shown, the three-phase power module includes three phases A, B, and C, and the independent power modules are numbered according to the three phases A, B, C and their number of stages. For example, the water-cooled PACK module is labeled as PACK_A. i PACK_B i and PACK_C i The energy storage converter module is marked as PCSM_A i PCSM_B i and PCSM_C i , where i = 1, 2, 3, ..., n, and n is a series.

[0058] In the description of this invention, the water inlet of the water-cooled PACK module is connected in parallel with the water inlet of the energy storage converter module, and is connected via a solenoid valve (also known as a module-side solenoid valve, such as...) Figure 1 As shown, the outlet pipes of the water distributor are connected according to the three-phase distribution. The solenoid valve is used to maintain the same water inflow to the water-cooled PACK module and the energy storage converter module.

[0059] Specifically, the water cooling system employs a dual flow and temperature balance method, as detailed below:

[0060] Temperatures are detected at the inlet of the three-phase water-cooled PACK module and the three-phase energy storage converter module; temperature matrix M. T As shown in the following formula:

[0061]

[0062] In the description of this invention, the water distributor is located above the energy storage converter module and is installed horizontally. The multiple outlets of the water distributor are all at the same height to maintain the pressure and flow balance within the energy storage converter module. Thus, the three-phase water pressure and flow velocity balance can be achieved through the characteristics of the water distributor, thereby realizing the three-phase dynamic thermal balance of the direct-connected energy storage converter.

[0063] In the description of this invention, both the inlet solenoid valve and the outlet solenoid valve utilize a flow control formula for flow control; wherein, the calculation process of the flow control formula includes:

[0064] Step S101: Collect the actual average temperature of the water-cooled PACK module and energy storage converter module in each independent power module, calculate the sum of the temperatures of the independent power modules of each three-phase stage, and sum the temperatures of all stages, then calculate the average value of the summed values ​​to obtain the average temperature term.

[0065] Step S102: Obtain the preset temperature setting value and subtract the average temperature value to obtain the temperature deviation.

[0066] Step S103: Obtain the integral coefficient and proportional coefficient common to the inlet solenoid valve and the outlet solenoid valve. Divide the integral coefficient by the complex frequency variable to obtain the integral term and the proportional coefficient to obtain the proportional term. Calculate the sum of the integral term and the proportional term to obtain the control coefficient.

[0067] Step S104: Multiply the temperature deviation by the control coefficient to obtain the flow control deviation between the inlet solenoid valve and the outlet solenoid valve, so as to realize the flow adjustment of the inlet solenoid valve and the outlet solenoid valve.

[0068] Specifically, the calculation formula for flow control is as follows:

[0069]

[0070] In the formula, ΔA inout It is a flow control deviation; T set It is the temperature setpoint; T Ai T Bi T Ci This represents the average actual temperature of the water-cooled PACK module and energy storage converter module in the i-level power modules of phases A, B, and C; k iin It is the integral coefficient for the inlet and outlet solenoid valve control, k pin It is the proportional control coefficient of the inlet and outlet solenoid valves.

[0071] In the description of this invention, the solenoid valve uses a cross-sectional area calculation formula to control the pressure and flow balance between the corresponding water-cooled PACK module and the energy storage converter module; wherein, the calculation process of the cross-sectional area calculation formula includes:

[0072] Step S201: Obtain the average actual temperature of the water-cooled PACK module and energy storage converter module within any independent power module, subtract the cumulative average actual temperature of all independent power modules within the same phase to obtain the single-phase temperature difference, and then compare the single-phase temperature difference with the controller transfer function (the controller transfer function expression is...). The temperature regulation component is obtained by multiplying the temperature influence factor by the temperature factor.

[0073] Step S202: Calculate the cumulative average value of liquid flow rate of all stages of solenoid valves in the phase where any independent power module is located, obtain the average flow rate value, divide it by the factor composed of the flow coefficient and the pressure difference between the two ends of the independent power module, obtain the flow rate term, and then multiply it by the liquid flow rate influence factor to obtain the flow rate correction component.

[0074] Step S203: Add the temperature regulation component and the flow correction component to obtain the change signal of the flow cross-sectional area used to control the opening of the solenoid valve.

[0075] Specifically, the formula for calculating the cross-sectional area is as follows:

[0076]

[0077] In the formula, Q j C is the liquid flow rate at the valve orifice; C is the flow coefficient; ΔA j It is the flow cross-sectional area at the inlet of the solenoid valve; ΔP j It is the pressure difference between the inlet and outlet of the solenoid valve; k i It is the temperature integral coefficient; k p It is the temperature proportionality coefficient; k Q It is the liquid flow rate influencing factor; k T It is a temperature-related factor; T Aj It is the actual average temperature of the water-cooled PACK module and energy storage converter module in the A-phase j-level power module, T Ai It represents the average actual temperature of the water-cooled PACK module and energy storage converter module in the A-phase i-level power module; S is a complex frequency variable; ΔP Aj It is the pressure difference between the water-cooled PACK module and the energy storage converter module in the A-phase j-level power module.

[0078] Where, k Q This is the liquid flow rate influence factor, with a default value of 0.5, k TAj k TBj k TCj It is a three-phase J-level temperature influence factor.

[0079] In the description of this invention, both the temperature influence factor and the flow rate influence factor can be automatically adjusted according to the actual operating conditions.

[0080] The automatic adjustment of the temperature influence factor based on actual operating conditions includes:

[0081] Step S301: Set up several experimental groups for all independent power modules in a single phase, record the actual temperature data of the water-cooled PACK module and the energy storage converter module in each independent power module, and calculate the deviation value between the independent power module and the average actual temperature in each experimental group.

[0082] Step S302: Select the minimum deviation of the independent power module within a single phase as the temperature influence factor.

[0083] Specifically, the liquid flow rate influence factor and temperature influence factor are adjusted according to the actual operating conditions to reduce the balance error between modules.

[0084] (1) Taking phase A as an example, select k TAj ={k T1 k T2 , ...k Tm}, j = 1, 2...n, according to the cross-sectional area calculation formula, control the solenoid valve on the control module side, i.e., the solenoid valve, and record the actual temperature data of the water-cooled PACK module and the energy storage converter module in the power module, where the temperature data of the i-th stage and j-th group is T. Aij .

[0085] (2) Calculate the deviation of each group of temperature data from the mean using the following formula, e1, e2, ... e m This indicates the deviation of each group.

[0086]

[0087] (2) Screening temperature influence factor k TAj The minimum value is min(e1, e2, ... e). m k at time TAj Similarly, the temperature influence factors k for phases B and C are derived. TBj k TCj .

[0088] Please see Figure 4 The present invention also provides a control method for a water-cooled system of a direct-connected energy storage converter, the control method comprising:

[0089] S1. The cooling water in the water-cooled unit is supplied to the water distributor using the inlet solenoid valve, and the actual temperature data in the three-phase power module is monitored in real time. The flow control deviation of the inlet solenoid valve is calculated in real time using the flow control formula, so as to adjust and control the pressure and flow of the cooling water inlet in real time.

[0090] In the description of this invention, the real-time calculation of the flow control deviation of the inlet solenoid valve using the flow control formula includes:

[0091] S11. Collect the actual average temperature of the water-cooled PACK module and energy storage converter module in each independent power module, calculate the sum of the temperatures of the independent power modules of each three-phase stage, and sum the temperatures of all stages. Then calculate the average value of the summed values ​​to obtain the average temperature term.

[0092] S12. Obtain the preset temperature setting value and subtract the average temperature value to obtain the temperature deviation.

[0093] S13. Obtain the integral coefficient and proportional coefficient of the inlet solenoid valve, divide the integral coefficient by the complex frequency variable to obtain the integral term and the proportional coefficient to obtain the proportional term, and calculate the sum of the integral term and the proportional term as the control coefficient.

[0094] S14. Multiply the temperature deviation by the control coefficient to obtain the flow control deviation of the inlet solenoid valve, so as to realize the flow adjustment of the inlet solenoid valve.

[0095] S2. Calculate the opening degree of the solenoid valve using the cross-sectional area calculation formula, and control the solenoid valve corresponding to each independent power module in real time to ensure that the water inlet flow of all water-cooled PACK modules and energy storage converter modules in the three-phase power module is consistent.

[0096] In the description of this invention, calculating the opening degree of the solenoid valve using the cross-sectional area calculation formula includes:

[0097] S21. Obtain the average actual temperature of the water-cooled PACK module and energy storage converter module in any independent power module, subtract the cumulative average actual temperature of all independent power modules in the same phase to obtain the single-phase temperature difference, and multiply the single-phase temperature difference with the controller transfer function and temperature influence factor to obtain the temperature regulation component.

[0098] S22. Calculate the cumulative average value of liquid flow rate of all stages of solenoid valves in the phase where any independent power module is located, obtain the average flow rate value, divide it by the factor composed of the flow coefficient and the pressure difference between the two ends of the independent power module, obtain the flow rate term, multiply it by the liquid flow rate influence factor, and obtain the flow rate correction component.

[0099] S23. Add the temperature regulation component and the flow correction component to obtain the signal of change in flow cross-sectional area used to control the opening of the solenoid valve.

[0100] S3. The cooling water discharged from the three-phase power module is transported to the water-cooled unit using the outlet solenoid valve. The flow control deviation of the outlet solenoid valve is calculated in real time using the flow control formula to adjust and control the pressure and flow of the cooling water outlet in real time, so as to realize the recycling of return water.

[0101] In summary, by utilizing the above-mentioned technical solution of this invention, three-phase water pressure and flow velocity balance is achieved through horizontal and vertical flow control, thereby realizing three-phase dynamic thermal balance and thermal management of each power component in the direct-connected energy storage converter. This provides closed-loop heat dissipation, high protection levels, and meets the environmental adaptability requirements of the direct-connected energy storage converter. It has the advantages of simple structure and flexible method, providing an effective solution for the module balance control of high-voltage direct-connected cascaded energy storage converters. It has wide applications in the field of water-cooled cascaded high-voltage, high-capacity power conversion. By maintaining temperature balance, it can reduce equipment performance degradation caused by temperature imbalance, improve system stability, and extend the service life of the entire equipment.

[0102] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

Claims

1. A water-cooling system for a direct-connected energy storage converter, characterized in that, include: Water-cooled unit, inlet solenoid valve, outlet solenoid valve, water distributor and three-phase power module; The water-cooled unit is connected to the inlet solenoid valve and the outlet solenoid valve respectively, and is used to provide cooling water for the three-phase power module. The inlet solenoid valve is connected to the inlet of the water distributor and is used to control the pressure and flow rate of the inlet water; The water outlet solenoid valve is connected to the three-phase water outlet pipe and is used to control the water outlet pressure and flow rate; The outlet pipes of the water distributor are connected to one end of the three-phase power module, and the other end of the three-phase power module is connected to the output pipe, which is then connected to the outlet solenoid valve.

2. The water-cooled system for a direct-connected energy storage converter according to claim 1, characterized in that, The three-phase power module includes three phases and several levels of independent power modules. The independent power modules located in the same phase are connected in parallel, and the number of independent power modules in each phase is the same. Each of the aforementioned independent power modules includes a water-cooled PACK module and an energy storage converter module.

3. The water-cooling system for a direct-connected energy storage converter according to claim 2, characterized in that, The water inlet of the water-cooled PACK module is connected in parallel with the water inlet of the energy storage converter module, and is connected to the outlet pipe of the water distributor through a solenoid valve. The solenoid valve is used to maintain the same water inlet flow rate for the water-cooled PACK module and the energy storage converter module.

4. The water-cooled system for a direct-connected energy storage converter according to claim 2, characterized in that, The water distributor is located above the energy storage converter module and is installed horizontally. The multiple outlets of the water distributor are all at the same height to maintain the pressure and flow balance within the energy storage converter module.

5. A water-cooled system for a direct-connected energy storage converter according to claim 3, characterized in that, Both the inlet solenoid valve and the outlet solenoid valve use flow control formulas for flow control. The calculation process of the flow control formula includes: Collect the actual average temperature of the water-cooled PACK module and energy storage converter module in each independent power module, calculate the average temperature of all independent power modules, and obtain the average temperature term. Obtain the preset temperature setting value and subtract the average temperature value to obtain the temperature deviation; Obtain the integral coefficient and proportional coefficient common to the inlet solenoid valve and the outlet solenoid valve. Divide the integral coefficient by the complex frequency variable to obtain the integral term and the proportional coefficient to obtain the proportional term. Calculate the sum of the integral term and the proportional term to obtain the control coefficient. Multiplying the temperature deviation by the control coefficient yields the flow control deviation between the inlet solenoid valve and the outlet solenoid valve, thereby enabling flow adjustment between the inlet and outlet solenoid valves.

6. A water-cooled system for a direct-connected energy storage converter according to claim 3, characterized in that, The solenoid valve uses the cross-sectional area calculation formula to control the pressure and flow balance between the corresponding water-cooled PACK module and the energy storage converter module. The calculation process of the cross-sectional area calculation formula includes: The average actual temperature of the water-cooled PACK module and energy storage converter module in any independent power module is obtained. The cumulative average actual temperature of all independent power modules in the same phase is subtracted to obtain the single-phase temperature difference. The single-phase temperature difference is then multiplied by the controller transfer function and the temperature influence factor to obtain the temperature regulation component. Calculate the cumulative average value of liquid flow rate of all stages of solenoid valves in the phase where any independent power module is located, obtain the average flow rate value, divide it by the factor composed of the flow coefficient and the pressure difference between the two ends of the independent power module, obtain the flow rate term, multiply it by the liquid flow rate influence factor, and obtain the flow rate correction component. The temperature regulation component and the flow correction component are added together to obtain the change signal of the flow cross-sectional area used to control the opening of the solenoid valve.

7. A water-cooled system for a direct-connected energy storage converter according to claim 6, characterized in that, Both the temperature influence factor and the flow rate influence factor can be automatically adjusted according to the actual operating conditions; The automatic adjustment of the temperature influence factor based on actual operating conditions includes: Several experimental groups were set up for all independent power modules in a single phase. The actual temperature data of the water-cooled PACK module and the energy storage converter module in each independent power module were recorded, and the deviation value between the independent power module and the actual average temperature in each experimental group was calculated. The minimum deviation of the independent power module within a single phase is selected as the temperature influence factor.

8. A control method for a direct-connected energy storage converter water-cooling system, used to control the direct-connected energy storage converter water-cooling system according to any one of claims 1-7, characterized in that, The control method includes: The cooling water in the water-cooled unit is supplied to the water distributor by the water inlet solenoid valve, and the actual temperature data in the three-phase power module is monitored in real time. The flow control deviation of the water inlet solenoid valve is calculated in real time using the flow control formula, so as to adjust and control the pressure and flow of the cooling water inlet in real time. The opening degree of the solenoid valve is calculated using the cross-sectional area calculation formula, and the solenoid valves corresponding to each independent power module are controlled in real time to ensure that the water inlet flow of all water-cooled PACK modules and energy storage converter modules in the three-phase power module is consistent. The cooling water discharged from the three-phase power module is delivered to the water-cooled unit using a water outlet solenoid valve. The flow control deviation of the water outlet solenoid valve is calculated in real time using a flow control formula to adjust and control the pressure and flow rate of the cooling water outlet in real time, so as to realize the recycling of return water.

9. The control method for a direct-connected energy storage converter water-cooling system according to claim 8, characterized in that, The real-time calculation of the flow control deviation of the inlet solenoid valve using the flow control formula includes: Collect the actual average temperature of the water-cooled PACK module and energy storage converter module in each independent power module, calculate the average temperature of all independent power modules, and obtain the average temperature term. Obtain the preset temperature setting value and subtract the average temperature value to obtain the temperature deviation; Obtain the integral coefficient and proportional coefficient of the inlet solenoid valve, divide the integral coefficient by the complex frequency variable to obtain the integral term and the proportional coefficient to obtain the proportional term, and calculate the sum of the integral term and the proportional term as the control coefficient. The flow control deviation of the inlet solenoid valve is obtained by multiplying the temperature deviation by the control coefficient, so as to realize the flow adjustment of the inlet solenoid valve.

10. The control method for a direct-connected energy storage converter water-cooling system according to claim 8, characterized in that, The calculation of the solenoid valve opening degree using the cross-sectional area calculation formula includes: The average actual temperature of the water-cooled PACK module and energy storage converter module in any independent power module is obtained. The cumulative average actual temperature of all independent power modules in the same phase is subtracted to obtain the single-phase temperature difference. The single-phase temperature difference is then multiplied by the controller transfer function and the temperature influence factor to obtain the temperature regulation component. Calculate the cumulative average value of liquid flow rate of all stages of solenoid valves in the phase where any independent power module is located, obtain the average flow rate value, divide it by the factor composed of the flow coefficient and the pressure difference between the two ends of the independent power module, obtain the flow rate term, multiply it by the liquid flow rate influence factor, and obtain the flow rate correction component. The temperature regulation component and the flow correction component are added together to obtain the change signal of the flow cross-sectional area used to control the opening of the solenoid valve.

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