Storage and charging system double-waterway thermal management system control method based on dynamic weight

Abstract

The invention discloses a storage and charging system double-waterway heat management system control method based on dynamic weight, relates to the technical field of energy storage system heat management, is applied to a double-waterway cooling system of a storage and charging system, and comprises the following steps: obtaining multi-dimensional dynamic parameters of the storage and charging system; judging whether the battery temperature is lower than a first preset temperature threshold and the temperature of the energy storage converter is lower than a second preset temperature threshold; if yes, respectively calculating a battery weight value and an energy storage converter weight value based on the multi-dimensional dynamic parameters; calculating a target distribution proportion based on the battery weight value and the energy storage converter weight value; determining a working mode of the double-waterway cooling system based on the target distribution proportion; and controlling an actuating mechanism of the double-waterway cooling system to act based on the battery temperature, the temperature of the energy storage converter and the working mode. The technical problem that in the prior art, refrigeration resources are wasted or heat dissipation is insufficient due to fixed proportion distribution is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal management of energy storage systems, and particularly to a control method for a dual-waterway thermal management system of a storage and charging system based on dynamic weights. Background Art

[0002] With the increase in the driving range of new energy vehicles and the improvement of the high-rate charging technology of power batteries, consumers' demand for fast charging is increasing day by day. At present, most of the charging piles on the market still adopt traditional natural cooling technology, which can no longer meet the needs of a wide range of users. Therefore, water-cooling systems are now equipped on charging piles. However, the traditional dual-waterway system uses a fixed ratio distribution (such as battery:PCS = 6:4), resulting in the problems of wasted cooling capacity under low load (it is measured that there is more than 20% of cold redundancy in 36% of the working conditions) and insufficient heat dissipation under high load (the temperature difference is more than 8 °C when both systems are fully loaded). Summary of the Invention

[0003] The purpose of the present invention is to provide a control method for a dual-waterway thermal management system of a storage and charging system based on dynamic weights to solve at least one of the above technical problems.

[0004] In a first aspect, an embodiment of the present invention provides a control method for a dual-waterway thermal management system of a storage and charging system based on dynamic weights, which is applied to the dual-waterway cooling system of the storage and charging system; the storage and charging system includes a battery and a power conversion system (PCS); the dual-waterway cooling system includes a battery cooling waterway and a charging equipment cooling waterway; the method includes: obtaining multi-dimensional dynamic parameters of the storage and charging system; the multi-dimensional dynamic parameters include the battery temperature and the temperature of the power conversion system (PCS); determining whether the battery temperature is lower than a first preset temperature threshold and the temperature of the power conversion system (PCS) is lower than a second preset temperature threshold; if so, calculating a battery weight value and a power conversion system (PCS) weight value respectively based on the multi-dimensional dynamic parameters; calculating a target allocation ratio based on the battery weight value and the power conversion system (PCS) weight value; determining the working mode of the dual-waterway cooling system based on the target allocation ratio; the working mode includes a battery priority mode, a balanced mode, and a power conversion system (PCS) priority mode; controlling the actuator of the dual-waterway cooling system to act based on the battery temperature, the temperature of the power conversion system (PCS), and the working mode; wherein, the calculation formula of the target allocation ratio includes: K = W batt / (W batt + W pcs + 0.001) In the formula, K is the target allocation ratio, W batt is the battery weight value, and W pcs is the power conversion system (PCS) weight value.

[0005] Further, a first heat exchanger is provided in the battery cooling water circuit, an air cooler and a second heat exchanger are provided in the charging device cooling water circuit, a compressor is provided in the refrigeration circuit of the first heat exchanger, the cooling circuit of the first heat exchanger and the refrigeration circuit of the second heat exchanger are connected through a three-way proportional valve, and the cooling circuit of the second heat exchanger is connected in series with the air cooler; based on the battery temperature, the temperature of the energy storage converter and the working mode, controlling the action of the actuator of the dual-waterway cooling system, including: based on the working mode, controlling the opening of the three-way proportional valve; based on proportional integral derivative control, controlling the operating power of the compressor and the rotational speed of the fan of the air cooler to control the battery temperature within a first preset temperature range and the temperature of the energy storage converter within a second preset temperature range.

[0006] Further, determining the working mode of the dual-waterway cooling system based on the target allocation ratio includes: if the target allocation ratio is greater than a first preset ratio threshold, determining that the working mode of the dual-waterway cooling system is the battery priority mode; if the target allocation ratio is between the first preset ratio threshold and a second preset ratio threshold, determining that the working mode of the dual-waterway cooling system is the balanced mode; if the target allocation ratio is less than the second preset ratio threshold, determining that the working mode of the dual-waterway cooling system is the energy storage converter priority mode.

[0007] Further, controlling the opening of the three-way proportional valve based on the working mode includes: if the working mode is the battery priority mode, controlling the opening of the three-way proportional valve within a first preset range; if the working mode is the balanced mode, controlling the opening of the three-way proportional valve within a second preset range; if the working mode is the energy storage converter priority mode, controlling the opening of the three-way proportional valve within a third preset range.

[0008] Further, the method further includes: if the battery temperature is not lower than a first preset temperature threshold, or the temperature of the energy storage converter is not lower than a second preset temperature threshold, performing an emergency cooling mode.

[0009] Further, the emergency cooling mode includes: if the battery temperature is not lower than the first preset temperature threshold, controlling the three-way proportional valve to be fully open on the battery cooling water circuit side and controlling the operating power of the compressor to be the maximum power; if the temperature of the energy storage converter is not lower than the second preset temperature threshold, controlling the opening of the three-way proportional valve based on the working mode, controlling the operating power of the energy storage converter to be lower than a preset power, and controlling the operating power of the compressor to be the maximum power.

[0010] Furthermore, the multi-dimensional dynamic parameters further include: battery discharge rate, battery temperature rise rate, power and efficiency of the energy storage converter, and fan speed of the dry cooler in the cooling water circuit of the charging device.

[0011] Furthermore, the calculation formula for the battery weight value includes: W batt =0.6*(T batt -40) 1.2 +0.3*ln(dT / dt + 1)+0.1*e (0.8*Crate) The calculation formula for the weight value of the energy storage converter includes: W pcs =0.4*(T igbt -60)+0.4*(power / η)+0.2*fan_speed_ratio In the formula, T batt represents the battery temperature, dT / dt represents the battery temperature rise rate, Crate represents the battery discharge rate, T igbt represents the temperature of the energy storage converter, power represents the power of the energy storage converter, η represents the efficiency of the energy storage converter, and fan_speed_ratio represents the fan speed.

[0012] The present invention provides a control method for a dual-waterway thermal management system of a storage and charging system based on dynamic weights, which quantifies multi-dimensional dynamic parameters of the storage and charging system into weight values of refrigeration requirements, realizes the change from threshold control to predictive allocation, takes the refrigeration capacity as a schedulable resource, dynamically reallocates according to the real-time threat degree, improves the overall energy efficiency of the system, and alleviates the technical problems of waste of refrigeration resources or insufficient heat dissipation caused by fixed ratio allocation in the existing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the specific embodiments or the description of the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0014] Figure 1 It is a flowchart of a control method for a dual-waterway thermal management system of a storage and charging system based on dynamic weights provided by an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a dual-waterway cooling system provided by an embodiment of the present invention.

[0015] In the figure: 1. Battery cooling water circuit; 2. Charging equipment cooling water circuit; 3. First heat exchanger; 4. Dry cooler; 5. Second heat exchanger; 6. Compressor; 7. Three-way proportional valve; 8. First circulation pump; 9. Second circulation pump; 10. Fan. Detailed implementation manners

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] Figure 1 is a flowchart of a control method for a dual-waterway thermal management system of a storage and charging system based on dynamic weights according to an embodiment of the present invention. This method is applied to the dual-waterway cooling system of the storage and charging system. Among them, the storage and charging system includes a battery and an energy storage converter.

[0018] Figure 2 is a schematic structural diagram of a dual-waterway cooling system according to an embodiment of the present invention. As Figure 2 shown, the dual-waterway cooling system includes a battery cooling water circuit 1 and a charging equipment cooling water circuit 2; among them, a first heat exchanger 3 is provided in the battery cooling water circuit 1, a dry cooler 4 and a second heat exchanger 5 are provided in the charging equipment cooling water circuit 2, a compressor 6 is provided in the refrigeration circuit of the first heat exchanger 3, the cooling circuit of the first heat exchanger 3 is connected to the refrigeration circuit of the second heat exchanger 4 through a three-way proportional valve 7, the cooling circuit of the second heat exchanger 5 is connected in series with the dry cooler 4, and a fan 10 is provided in the dry cooler 4.

[0019] Specifically, as Figure 2 shown, a first circulation pump 8 is further provided on the battery cooling water circuit 1, and a second circulation pump 9 is further provided on the charging equipment cooling water circuit 2.

[0020] Specifically, as Figure 1 shown, the control method provided by the embodiment of the present invention specifically includes the following steps: Step S102, obtaining multi-dimensional dynamic parameters of the storage and charging system; the multi-dimensional dynamic parameters include the battery temperature and the temperature of the energy storage converter.

[0021] Step S104, determining whether the battery temperature is lower than a first preset temperature threshold and the temperature of the energy storage converter is lower than a second preset temperature threshold; if so, execute step S106; if not, execute step S114.

[0022] Preferably, the first preset temperature threshold is 40 °C, and the second preset temperature threshold is 60 °C.

[0023] Step S106: Calculate the battery weight value and the energy storage converter weight value respectively based on the multi-dimensional dynamic parameters.

[0024] Step S108: Calculate the target allocation ratio based on the battery weight value and the energy storage converter weight value.

[0025] Step S110: Determine the working mode of the dual-waterway cooling system based on the target allocation ratio; the working modes include the battery priority mode, the balanced mode, and the energy storage converter priority mode.

[0026] Step S112: Control the actuator of the dual-waterway cooling system to act based on the battery temperature, the temperature of the energy storage converter, and the working mode.

[0027] Step S114: Execute the emergency cooling mode.

[0028] Among them, the calculation formula for the target allocation ratio includes: K = W batt / (W batt + W pcs + 0.001) In the formula, K is the target allocation ratio, W batt is the battery weight value, W pcs is the energy storage converter weight value.

[0029] Specifically, the multi-dimensional dynamic parameters further include: the battery discharge rate, the battery temperature rise rate, the power and efficiency of the energy storage converter, and the fan speed of the air cooler in the cooling water path of the charging device.

[0030] The calculation formula for the battery weight value includes: W batt = 0.6*(T batt - 40) 1.2 + 0.3*ln(dT / dt + 1) + 0.1*e (0.8*Crate) The calculation formula for the energy storage converter weight value includes: W pcs = 0.4*(T igbt - 60) + 0.4*(power / η) + 0.2*fan_speed_ratio In the formula, T batt represents the battery temperature, dT / dt represents the battery temperature rise rate, Crate represents the battery discharge rate, Tigbt represents the temperature of the energy storage converter, power represents the power of the energy storage converter, η represents the efficiency of the energy storage converter, and fan_speed_ratio represents the fan speed.

[0031] Specifically, step S110 includes the following steps: Step S1101, if the target allocation ratio is greater than the first preset ratio threshold, determine that the working mode of the dual-waterway cooling system is the battery priority mode; for example, the first preset ratio threshold is 0.7.

[0032] Step S1102, if the target allocation ratio is between the first preset ratio threshold and the second preset ratio threshold, determine that the working mode of the dual-waterway cooling system is the balanced mode; for example, the second preset ratio threshold is 0.3.

[0033] Step S1103, if the target allocation ratio is less than the second preset ratio threshold, determine that the working mode of the dual-waterway cooling system is the energy storage converter priority mode.

[0034] Specifically, step S112 further includes the following steps: Step S1121, based on the working mode, control the opening degree of the three-way proportional valve; Specifically, if the working mode is the battery priority mode, control the opening degree of the three-way proportional valve within the first preset range; for example, the first preset range includes 80% - 100%, that is, control the opening degree of the three-way proportional valve on the battery cooling waterway side to be 80% - 100%.

[0035] If the working mode is the balanced mode, control the opening degree of the three-way proportional valve within the second preset range; for example, the second preset range includes 30% - 80%, that is, control the opening degree of the three-way proportional valve on the battery cooling waterway side to be 30% - 80%.

[0036] If the working mode is the energy storage converter priority mode, control the opening degree of the three-way proportional valve within the third preset range. For example, the third preset range includes 0 - 30%, that is, control the opening degree of the three-way proportional valve on the battery cooling waterway side to be 0 - 30%.

[0037] Step S1122, based on the proportional integral derivative control, control the operating power of the compressor and the rotational speed of the fan of the dry cooler to control the battery temperature within the first preset temperature range and the temperature of the energy storage converter within the second preset temperature range.

[0038] Optionally, the first preset temperature range includes 20°C - 40°C; the second preset temperature range includes 40°C - 60°C.

[0039] Specifically, in the embodiment of the present invention, the emergency cooling mode includes: If the battery temperature is not lower than the first preset temperature threshold, control the three-way proportional valve to be fully open on the battery cooling waterway side, and control the operating power of the compressor to be the maximum power; If the temperature of the energy storage converter is not lower than the second preset temperature threshold, control the opening of the three-way proportional valve based on the working mode, control the operating power of the energy storage converter to be lower than the preset power, and control the operating power of the compressor to be the maximum power.

[0040] Specifically, if the battery temperature continuously is not lower than the first preset temperature threshold, or the temperature of the energy storage converter continuously is not lower than the second preset temperature threshold, perform three-level load reduction on the energy storage converter until the energy storage converter is shut down and the charging circuit is cut off.

[0041] Specifically, the control strategy in step S112 further includes: if the battery temperature is within the first preset temperature range and the temperature of the energy storage converter is within the second preset temperature range, execute the optimization strategy; specifically, on the premise of ensuring that the battery temperature and the temperature of the energy storage converter do not exceed the first preset temperature range and the second preset temperature range respectively, optimize the power of the compressor to achieve the purpose of energy saving.

[0042] In an optional implementation manner provided by the embodiment of the present invention, the optimization strategy includes: (1) The compressor speed is adjusted step by step every 5%; (2) Give priority to reducing the flow rate of the high-threat branch by 5%; (3) Record the actuator feedback status of the optimal energy efficiency parameters every 30 minutes.

[0043] Preferably, the method provided by the embodiment of the present invention further includes a fault mode, including: Determine whether a sensor fault or a communication interruption fault occurs; If a sensor fault occurs, switch to the standby system; if a communication interruption fault occurs, perform local backup operation; Ensure battery cooling throughout the process, control the circulating pump to run at the lowest speed, control the opening of the three-way proportional valve to be 20%, and cache the operating state.

[0044] As can be seen from the above description, the present invention provides a control method for a dual-waterway thermal management system of a storage and charging system based on dynamic weights, quantifies the multi-dimensional dynamic parameters of the storage and charging system into weight values of cooling requirements, realizes the change from threshold control to predictive allocation, takes the cooling capacity as a schedulable resource, dynamically reallocates according to the real-time threat degree, improves the overall energy efficiency of the system, and alleviates the technical problems of waste of cooling resources or insufficient heat dissipation caused by fixed ratio allocation in the prior art.

[0045] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0046] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A control method for a dual-waterway thermal management system of a storage and charging system based on dynamic weights, characterized in that, Dual-waterway cooling system applied to a storage and charging system; the storage and charging system includes a battery and an energy storage converter; the dual-waterway cooling system includes a battery cooling waterway and a charging device cooling waterway; the method includes: Obtain multi-dimensional dynamic parameters of the storage and charging system; the multi-dimensional dynamic parameters include the battery temperature and the temperature of the energy storage converter; Determine whether the battery temperature is lower than a first preset temperature threshold and the temperature of the energy storage converter is lower than a second preset temperature threshold; If so, calculate a battery weight value and an energy storage converter weight value respectively based on the multi-dimensional dynamic parameters; Calculate a target allocation ratio based on the battery weight value and the energy storage converter weight value; Determine the working mode of the dual-waterway cooling system based on the target allocation ratio; the working modes include a battery priority mode, a balanced mode, and an energy storage converter priority mode; Control the actuator of the dual-waterway cooling system to act based on the battery temperature, the temperature of the energy storage converter, and the working mode; Among them, the calculation formula of the target allocation ratio includes: K = W batt / (W batt + W pcs + 0.001) Where K is the target allocation ratio, and W batt is the battery weight value, and W pcs is the energy storage converter weight value.

2. The method according to claim 1, wherein: A first heat exchanger is arranged in the battery cooling waterway, an air cooler and a second heat exchanger are arranged in the charging device cooling waterway, a compressor is arranged in the refrigeration circuit of the first heat exchanger, the cooling circuit of the first heat exchanger is communicated with the refrigeration circuit of the second heat exchanger through a three-way proportional valve, and the cooling circuit of the second heat exchanger is connected in series with the air cooler; Controlling the actuator of the dual-waterway cooling system based on the battery temperature, the temperature of the energy storage converter, and the working mode includes: Controlling the opening degree of the three-way proportional valve based on the working mode; Based on proportional-integral-derivative control, control the operating power of the compressor and the rotational speed of the fan of the air cooler to control the battery temperature within a first preset temperature range and the temperature of the energy storage converter within a second preset temperature range.

3. The method according to claim 2, wherein: Determining the working mode of the dual-waterway cooling system based on the target allocation ratio includes: If the target allocation ratio is greater than a first preset ratio threshold, determine that the working mode of the dual-waterway cooling system is the battery priority mode; If the target allocation ratio is between the first preset ratio threshold and the second preset ratio threshold, determine that the working mode of the dual-waterway cooling system is the balanced mode; If the target allocation ratio is less than the second preset ratio threshold, determine that the working mode of the dual-waterway cooling system is the energy storage converter priority mode.

4. The method according to claim 2, wherein: Controlling the opening degree of the three-way proportional valve based on the working mode includes: If the working mode is the battery priority mode, control the opening degree of the three-way proportional valve within a first preset range; If the working mode is the balanced mode, control the opening degree of the three-way proportional valve within a second preset range; If the working mode is the energy storage converter priority mode, control the opening degree of the three-way proportional valve within a third preset range.

5. The method according to claim 2, characterized in that: The method further includes: if the battery temperature is not lower than the first preset temperature threshold, or the temperature of the energy storage converter is not lower than the second preset temperature threshold, execute an emergency cooling mode.

6. The method according to claim 5, wherein: The emergency cooling mode includes: If the battery temperature is not lower than the first preset temperature threshold, control the three-way proportional valve to be fully open on the battery cooling water circuit side, and control the operating power of the compressor to be the maximum power; If the temperature of the energy storage converter is not lower than the second preset temperature threshold, control the opening degree of the three-way proportional valve based on the working mode, control the operating power of the energy storage converter to be lower than the preset power, and control the operating power of the compressor to be the maximum power.

7. The method according to claim 1, wherein: The multi-dimensional dynamic parameters further include: battery discharge rate, battery temperature rise rate, power and efficiency of the energy storage converter, and fan speed of the air cooler in the charging device cooling water circuit.

8. The method according to claim 7, characterized in that: The calculation formula for the battery weight value includes: W batt =0.6*(T batt -40) 1.2 +0.3*ln(dT / dt + 1)+0.1*e (0.8*Crate) The calculation formula for the energy storage converter weight value includes: W pcs = 0.4*(T igbt - 60)+0.4*(power / η)+0.2*fan_speed_ratio Where, T batt represents the battery temperature, dT / dt represents the battery temperature rise rate, Crate represents the battery discharge rate, T igbt represents the temperature of the energy storage converter, power represents the power of the energy storage converter, η represents the efficiency of the energy storage converter, and fan_speed_ratio represents the fan speed.

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