Battery box fan speed regulation control method and energy storage system

Abstract

The invention relates to a battery box fan speed regulation control method and an energy storage system, relates to the field of electrochemical energy storage, in particular to the field of battery thermal management control, and provides an energy storage battery box fan speed regulation control method. A battery management system (BMS) collects the temperature of a battery cell in a battery box in real time and monitors the working state of a speed regulation fan; the BMS controls starting, rotating speed and stopping of the speed regulation fan in a combined mode according to the maximum temperature, the minimum temperature, the temperature range and the temperature change rate of the energy storage battery, the BMS judges the fault state of the speed regulation fan according to the fan driving signal and the speed regulation fan state signal, if the fault state is achieved, the BMS actively cuts off a fan power source, meanwhile, a battery system is cut off, and the energy storage battery is started. The reliability of thermal management of the energy storage battery is effectively improved, the consistency of the working temperature of the battery is guaranteed, meanwhile, the thermal management loss is reduced, and the charging and discharging efficiency of the energy storage battery system is improved.

Description

Technical Field

[0001] The invention relates to a battery box fan speed regulation control method and an energy storage system, and belongs to the field of battery thermal management control. Background Art

[0002] In recent years, with the rapid development of large-scale electrochemical energy storage power stations, the consistency problem of large-scale series-parallel energy storage batteries has become increasingly prominent, mainly including voltage consistency, temperature consistency and other issues.

[0003] Traditional air-cooled battery plug-ins usually use an open-loop fan control method. When the fan is operating at full power or in a shutdown state, there is a lack of fan status monitoring, resulting in high fan operation losses and the inability to effectively monitor fan failures. There is a risk of fan burnout, which poses a major safety hazard to the stable operation of the energy storage battery. Summary of the invention

[0004] The purpose of the present invention is to provide a battery box fan speed control method and an energy storage system to solve the problems of low temperature consistency of multiple batteries in an energy storage battery box and large thermal management loss.

[0005] To achieve the above purpose, a battery box fan speed control method of the present invention is characterized by:

[0006] 1) Collect and calculate the maximum temperature, temperature change rate and temperature range in the battery box;

[0007] 2) If the maximum temperature is greater than a preset high temperature start setting or the temperature extreme difference is greater than a preset extreme difference start setting, the fan speed is adjusted according to the temperature change rate;

[0008] If the maximum temperature is less than a preset high temperature stop value and the temperature extreme difference is less than a preset extreme difference stop value, the fan will be turned off;

[0009] The fan is used to dissipate heat from the battery cells in the battery box through air flow.

[0010] The maximum temperature, temperature extreme difference and temperature change rate of the energy storage battery are used to jointly control the start, speed and stop of the speed-regulating fan, thereby improving the temperature consistency of the energy storage battery and reducing thermal management losses.

[0011] Furthermore, in a battery box fan speed control method described in the present invention, in the step 2), adjusting the fan speed according to the temperature change rate includes: setting at least two intervals according to the size of the temperature change rate, when the collected temperature change rate falls into the interval with a smaller temperature change rate, the corresponding fan speed is lower than the fan speed corresponding to when the collected temperature change rate falls into the interval with a larger temperature change rate.

[0012] Different fan speeds are set according to the real-time temperature change rate, effectively reducing the thermal management loss of the battery box.

[0013] Furthermore, in a battery box fan speed control method described in the present invention, before step 2), it is also necessary to determine whether the fan is started; if the fan is in the started state, when the temperature change rate is not a negative value, the speed is increased; when the temperature change rate is a negative value, the current speed is maintained.

[0014] When the temperature is high, the fan speed is controlled by collecting the real-time temperature change rate. When the temperature change rate increases or remains unchanged, the speed is increased to dissipate heat. When the temperature change rate decreases, the fan maintains the current speed, effectively reducing the thermal management loss of the battery box and achieving energy saving of the system.

[0015] Furthermore, a battery box fan speed control method described in the present invention collects in real time a status signal of the speed-regulating fan and a fan speed control signal: if the fan speed control signal is 0, and the status signal of the speed-regulating fan collected in real time is a speed signal with a certain frequency or a start-up state, or the fan speed control signal is greater than 0, and the status signal of the speed-regulating fan collected in real time is no speed or a stationary state, then it is determined that the speed-regulating fan is faulty; if the fan speed control signal is 0, and the status signal of the speed-regulating fan collected in real time is no speed or a stationary state, or the fan speed control signal is greater than 0, and the status signal of the speed-regulating fan collected in real time is a speed signal with a certain frequency or a start-up state, then it is determined that the speed-regulating fan is normal.

[0016] By comparing the fan speed signal with the real-time acquisition of the speed regulating fan status signal, the fan fault detection and protection are realized, which greatly improves the battery cycle life.

[0017] A battery box fan speed control method, comprising the following steps:

[0018] 1) Collect and calculate the minimum temperature, temperature change rate and temperature range in the battery box;

[0019] 2) If the minimum temperature is less than a preset low temperature start setting or the temperature extreme difference is greater than a preset extreme difference start setting, the fan speed is adjusted according to the temperature change rate;

[0020] If the minimum temperature is greater than a preset low temperature stop value and the temperature extreme difference is less than a preset extreme difference stop value, the fan will be turned off;

[0021] The fan is used to dissipate heat from the battery cells in the battery box through air flow.

[0022] The minimum temperature, temperature extreme difference and temperature change rate of the energy storage battery are used to jointly control the start, speed and stop of the speed-regulating fan, thereby improving the temperature consistency of the energy storage battery and reducing thermal management losses.

[0023] Furthermore, in the battery box fan speed control method described in the present invention, in the step 2), adjusting the fan speed according to the temperature change rate includes: setting at least two intervals according to the temperature change rate, and when the collected temperature change rate falls into the interval with a smaller temperature change rate, the corresponding fan speed is lower than the corresponding fan speed when the collected temperature change rate falls into the interval with a larger temperature change rate. .

[0024] Different fan speeds are set according to the real-time temperature change rate, effectively reducing the thermal management loss of the battery box.

[0025] Furthermore, in the battery box fan speed control method described in the present invention, before step 2), it is also necessary to determine whether the fan is started; if the fan is in the started state, when the temperature change rate is not a negative value, the current speed is maintained; when the temperature change rate is a negative value, the speed is increased.

[0026] When the temperature is low, the fan speed is controlled by collecting the real-time temperature change rate. When the temperature change rate increases or remains unchanged, the current speed is maintained. When the temperature change rate decreases, in order to balance the temperature inside the battery box, the fan speed is increased, which effectively reduces the thermal management loss of the battery box and effectively improves the consistency of the operating temperature of the batteries in the energy storage battery box.

[0027] Furthermore, a battery box fan speed control method described in the present invention collects in real time a status signal of the speed-regulating fan and a fan speed control signal: if the fan speed control signal is 0, and the status signal of the speed-regulating fan collected in real time is a speed signal with a certain frequency or a start-up state, or the fan speed control signal is greater than 0, and the status signal of the speed-regulating fan collected in real time is no speed or a stationary state, then it is determined that the speed-regulating fan is faulty; if the fan speed control signal is 0, and the status signal of the speed-regulating fan collected in real time is no speed or a stationary state, or the fan speed control signal is greater than 0, and the status signal of the speed-regulating fan collected in real time is a speed signal with a certain frequency or a start-up state, then it is determined that the speed-regulating fan is normal.

[0028] By comparing the fan speed signal with the real-time acquisition of the speed regulating fan status signal, the fan fault detection and protection are realized, which greatly improves the battery cycle life.

[0029] A battery box fan speed control system includes a processor, wherein the processor is used to execute instructions for implementing the battery box fan speed control method.

[0030] An energy storage system includes at least one battery box, wherein the battery box includes the battery box fan speed control system as described above.

[0031] The present invention adopts a fan with speed regulation function and state monitoring function, and uses the maximum temperature, minimum temperature, temperature range and temperature change rate of the energy storage battery to jointly control the start, speed and stop of the speed regulating fan, thereby improving the temperature consistency of the energy storage battery and reducing the thermal management loss. The battery management system BMS determines the fault state of the speed regulating fan according to the output fan drive signal and the state signal of the speed regulating fan. If it is a fault state, the BMS actively cuts off the power supply of the fan and cuts off the battery system at the same time to protect the battery system. The present invention effectively improves the consistency of the operating temperature of the batteries in the energy storage battery box, reduces the thermal management loss, and realizes the fault detection and protection of the fan, improves the operating reliability of the energy storage battery box, and effectively improves the battery cycle life. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flow chart of a method for controlling a speed-adjustable fan under high temperature conditions in an embodiment of the present invention;

[0033] Figure 2 is a flow chart of a speed regulating fan control method under low temperature conditions in an embodiment of the present invention;

[0034] Figure 3 It is a flow chart of a fault detection method in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0036] The present invention proposes a battery box fan speed control method and energy storage system. The battery management system BMS collects the temperature in the battery box in real time and monitors the working state of the speed-adjusting fan. The BMS controls the start, speed and stop of the speed-adjusting fan according to the maximum temperature, minimum temperature, temperature range and temperature change rate of the energy storage battery. The BMS determines the fault state of the speed-adjusting fan according to the fan drive signal and the state signal of the speed-adjusting fan. If it is a fault state, the BMS actively cuts off the fan power supply, sets the speed to zero, and cuts off the battery system at the same time.

[0037] Battery box fan speed control method embodiment:

[0038] In this embodiment, the battery management system BMS collects the temperature Tn of the energy storage battery in real time through the temperature sensor, and calculates the maximum temperature Tmax, the minimum temperature Tmin, the temperature change rate K, and the temperature extreme difference ΔT, where n is the number of temperature sensors matching the energy storage battery, the temperature change rate is the maximum temperature change rate, and the temperature extreme difference ΔT=Tmax-Tmin;

[0039] The battery management system BMS is configured with the following constants for starting the speed-adjusting fan: high temperature starting constant THon, low temperature starting constant TLon, and extreme difference starting constant TDon; the battery management system BMS is configured with the following constants for the temperature change rate Kr1, Kr2, and Kr3, and Kr1<Kr2<Kr3; the battery management system BMS is configured with the following constants for stopping the speed-adjusting fan: high temperature stopping constant THoff, low temperature stopping constant TLoff, and extreme difference stopping constant TDoff;

[0040] The starting speed of the speed-regulating fan is proportional to the temperature change rate of the energy storage battery within a certain range.

[0041] like Figure 1 As shown in the flow chart of the speed regulating fan control method under high temperature conditions in an embodiment of the present invention, the maximum temperature, minimum temperature, temperature change rate and temperature range of the battery box are collected. When the fan is not started, the high temperature strategy in the starting speed strategy of the speed regulating fan is adjusted by adjusting the temperature change rate to adjust the fan speed. When the fan is started, the high temperature strategy in the strategy in which the speed regulating fan speed changes with the temperature is used to adjust the fan speed.

[0042] like Figure 2 As shown in the flow chart of the speed regulating fan control method under low temperature conditions in an embodiment of the present invention, the maximum temperature, minimum temperature, temperature change rate and temperature range of the battery box are collected. When the fan is not started, the low temperature strategy in the starting speed strategy of the speed regulating fan is adjusted by adjusting the temperature change rate to adjust the fan speed. When the fan is started, the fan speed is adjusted by the low temperature strategy in the strategy in which the speed regulating fan speed changes with the temperature.

[0043] (1) In this embodiment, the battery management system BMS adjusts the starting speed strategy of the speed regulating fan according to the temperature change rate of the energy storage battery as follows:

[0044] When controlling the fan to start from static state:

[0045] When the temperature change rate K is less than Kr1, the battery management system BMS adjusts the fan start speed to 1 / 3 of the rated speed;

[0046] When the temperature change rate Kr1≤K<Kr2, the battery management system BMS adjusts the fan start speed to 2 / 3 of the rated speed;

[0047] When the temperature change rate K ≥ Kr3, the battery management system BMS adjusts the fan starting speed to the rated speed.

[0048] (2) The strategy of changing the speed of the speed-adjusting fan with the temperature in this embodiment is as follows:

[0049] Under high temperature conditions, when Tmax>THon or ΔT>TDon and it lasts for a certain period of time, the battery management system BMS controls the speed-adjustable fan to start; when Tmax<THoff and ΔT<TDoff and it lasts for a certain period of time, the battery management system BMS controls the speed-adjustable fan to zero speed;

[0050] Under low temperature conditions, when Tmin<TLon or ΔT>TDon and maintains for a certain time, the battery management system BMS controls the speed regulating fan to start; when Tmin>TLoff and ΔT<TDoff and maintains for a certain time, the battery management system BMS controls the speed regulating fan to zero.

[0051] (3) In this embodiment, the strategy for adjusting the speed of the speed-regulating fan based on the real-time temperature change rate of the energy storage battery is as follows:

[0052] Under high temperature conditions, after the speed regulating fan has started:

[0053] K≥0, increase the speed in a certain step length, up to the rated speed;

[0054] K<0, keep the speed unchanged until K=0.

[0055] Under low temperature conditions, after the speed regulating fan has started:

[0056] K≥0, keep the speed unchanged;

[0057] K<0, the speed increases in certain steps up to the rated speed.

[0058] (4) The flowchart of the fault detection method in the embodiment of the present invention is as follows Figure 3 As shown in the figure, the strategy of jointly judging the fault status by the real-time collected status signal of the speed regulating fan and the fan speed control signal is as follows:

[0059] SF is the status signal of the speed regulating fan collected in real time by the battery management system BMS, and R is the fan speed control signal of the battery management system BMS:

[0060] When R=0, that is, the battery management system BMS does not send a speed command to the speed-regulating fan, if SF is a speed signal with a certain frequency or is in a startup state, it is determined that the speed-regulating fan is faulty; if SF is no speed or is in a stationary state, it is determined that the speed-regulating fan is normal;

[0061] When R>0, the battery management system BMS has sent a speed command to the speed-regulating fan. If SF is a speed signal of a certain frequency or is in a starting state, the speed-regulating fan is judged to be normal. If SF is no speed or is in a stationary state, the speed-regulating fan is judged to be faulty.

[0062] When the battery management system BMS determines that the speed regulating fan is in a fault state, the BMS cuts off the power supply of the speed regulating fan, sets the fan speed control signal R to zero, and cuts off the battery system to achieve fault isolation.

[0063] Battery box fan speed control system implementation example:

[0064] A battery box fan speed control system of the present invention controls a plurality of fans in the battery box through a processor to perform temperature balance control for the battery box. The processor executes instructions to implement a battery box fan speed control method. The corresponding battery box fan speed control method has been introduced clearly enough in the method embodiment and will not be repeated here.

[0065] Energy storage system implementation example:

[0066] An energy storage system of the present invention includes an energy storage battery box that adopts an energy storage system battery box fan speed control method of the present invention, the energy storage battery box includes a box body and a plurality of single cells arranged in the box body, temperature sensors are arranged at different positions in the battery box for collecting the temperature of different areas or different single cells; a cooling fan is arranged on the box body and / or in the box body, the cooling fan can form air flow between the single cells in the box body and inside and outside the box body, so as to achieve temperature balance and heat dissipation in the battery box. The corresponding energy storage system battery box fan speed control method has been introduced clearly enough in the method embodiment, and will not be repeated here.

Claims

1. A battery box fan speed control method, characterized in that: The steps include: 1) Collect and calculate the maximum temperature, temperature change rate and temperature range in the battery box; 2) If the maximum temperature is greater than a preset high temperature start setting or the temperature extreme difference is greater than a preset extreme difference start setting, the fan speed is adjusted according to the temperature change rate; If the maximum temperature is less than a preset high temperature stop value and the temperature extreme difference is less than a preset extreme difference stop value, the fan will be turned off; The fan is used to dissipate heat from battery cells in the battery box through air flow.

2. The battery box fan speed control method according to claim 1 is characterized in that: In the step 2), adjusting the fan speed according to the temperature change rate includes: setting at least two intervals according to the size of the temperature change rate, when the collected temperature change rate falls into the interval with a smaller temperature change rate, the corresponding fan speed is lower than the fan speed corresponding to when the collected temperature change rate falls into the interval with a larger temperature change rate.

3. The battery box fan speed control method according to claim 1, characterized in that: Before step 2), it is also necessary to determine whether the fan is started; if the fan is started, when the temperature change rate is not a negative value, the speed is increased; when the temperature change rate is a negative value, the current speed is maintained.

4. The battery box fan speed control method according to claim 3 is characterized in that: Real-time collection of the status signal of the speed-regulating fan and the fan speed control signal: if the fan speed control signal is 0, and the real-time collection of the status signal of the speed-regulating fan is a speed signal with a certain frequency or a startup state, or the fan speed control signal is greater than 0, and the real-time collection of the status signal of the speed-regulating fan is no speed or a stationary state, then it is determined that the speed-regulating fan is faulty; if the fan speed control signal is 0, and the real-time collection of the status signal of the speed-regulating fan is no speed or a stationary state, or the fan speed control signal is greater than 0, and the real-time collection of the status signal of the speed-regulating fan is a speed signal with a certain frequency or a startup state, then it is determined that the speed-regulating fan is normal.

5. A battery box fan speed control method, characterized in that: The steps include: 1) Collect and calculate the minimum temperature, temperature change rate and temperature range in the battery box; 2) If the minimum temperature is less than a preset low temperature start setting or the temperature extreme difference is greater than a preset extreme difference start setting, the fan speed is adjusted according to the temperature change rate; If the minimum temperature is greater than a preset low temperature stop value and the temperature extreme difference is less than a preset extreme difference stop value, the fan will be turned off; The fan is used to dissipate heat from the battery cells in the battery box through air flow.

6. The battery box fan speed control method according to claim 5 is characterized in that: In the step 2), adjusting the fan speed according to the temperature change rate includes: setting at least two intervals according to the size of the temperature change rate, when the collected temperature change rate falls into the interval with a smaller temperature change rate, the corresponding fan speed is lower than the fan speed corresponding to when the collected temperature change rate falls into the interval with a larger temperature change rate.

7. The battery box fan speed control method according to claim 5, characterized in that: Before step 2), it is also necessary to determine whether the fan is started; if the fan is started, when the temperature change rate is not a negative value, the current speed is maintained; when the temperature change rate is a negative value, the speed is increased.

8. The battery box fan speed control method according to claim 7, characterized in that: Real-time collection of the status signal of the speed-regulating fan and the fan speed control signal: if the fan speed control signal is 0, and the real-time collection of the status signal of the speed-regulating fan is a speed signal with a certain frequency or a startup state, or the fan speed control signal is greater than 0, and the real-time collection of the status signal of the speed-regulating fan is no speed or a stationary state, then it is determined that the speed-regulating fan is faulty; if the fan speed control signal is 0, and the real-time collection of the status signal of the speed-regulating fan is no speed or a stationary state, or the fan speed control signal is greater than 0, and the real-time collection of the status signal of the speed-regulating fan is a speed signal with a certain frequency or a startup state, then it is determined that the speed-regulating fan is normal.

9. A battery box fan speed control system, characterized in that: It includes a processor, which is used to execute instructions to implement the battery box fan speed control method as claimed in any one of claims 1 to 8.

10. An energy storage system, characterized in that: It comprises at least one battery box, and the battery box comprises the battery box fan speed control system as described in claim 9.

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