A temperature-based battery energy storage system power supply method

Abstract

The present invention discloses a temperature-based power supply method for a battery energy storage system, the method comprising the following steps: S1. For each battery pack in the energy storage system, multiple discrete power points are determined, and the critical power that causes the battery pack temperature to rise rapidly is tested; S2. For each battery pack in the energy storage system, it is made to work at the critical power, and the maximum working time of the battery pack at the critical power is measured as the maximum working time of the battery pack; S3. Based on the external power supply demand of the energy storage system, the critical power of each battery pack in the energy storage system, and the maximum working time of each battery pack in the energy storage system, the power supply strategy of the energy storage system is designed. The present invention can ensure that when the battery energy storage system is supplying power to the outside, the temperature of the battery pack in the energy storage system will not be higher than the maximum allowable temperature, thereby avoiding damage to the battery pack and effectively ensuring the safety of the battery energy storage system.

Description

Technical Field

[0001] The present invention relates to battery energy storage, and in particular to a temperature-based power supply method for a battery energy storage system. Background Art

[0002] Battery energy storage systems can achieve energy storage and bidirectional power flow. At present, battery energy storage systems usually use Boost converters and battery packs in series to form a minimum energy storage unit, and then multiple minimum energy storage units are connected in parallel to form a battery energy storage system. However, when the battery energy storage system is used to supply power to the outside, each battery pack will generate heat as the output power increases. When the temperature is too high, it may cause battery damage or even cause safety accidents. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a temperature-based battery energy storage system power supply method, which can ensure that when the battery energy storage system is supplying power to the outside, the temperature of the battery pack in the energy storage system will not be higher than the maximum allowable temperature, thereby avoiding damage to the battery pack and effectively ensuring the safety of the battery energy storage system.

[0004] The object of the present invention is achieved through the following technical solutions: a temperature-based battery energy storage system power supply method, the battery energy storage system includes a plurality of battery packs, and the plurality of battery packs jointly realize the external power supply of the battery energy storage system; the method comprises the following steps:

[0005] S1. For each battery pack in the energy storage system, determine multiple discrete power points and test the critical power that causes the battery pack temperature to rise rapidly;

[0006] S2. For each battery pack in the energy storage system, operate it at a critical power and measure the maximum operating time of the battery pack at the critical power as the maximum operating time of the battery pack;

[0007] S3. Design a power supply strategy for the energy storage system based on the external power supply demand of the energy storage system, the critical power of each battery pack in the energy storage system, and the maximum working time of each battery pack in the energy storage system.

[0008] The beneficial effects of the present invention are as follows: the present invention first tests the critical power of each battery pack, then measures the maximum working time of the battery pack under the critical power, and then based on the external power supply demand of the energy storage system, ensures that the output power of each battery pack does not exceed the critical power when supplying power to the outside, and the working time is lower than the maximum working time, so that when the battery energy storage system supplies power to the outside, the temperature of the battery pack in the energy storage system will not be higher than the maximum allowable temperature, thereby avoiding damage to the battery pack and effectively ensuring the safe use of the battery energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0010] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0011] like Figure 1 As shown, a temperature-based battery energy storage system power supply method is characterized in that: the battery energy storage system includes multiple battery packs, and the multiple battery packs jointly realize the external power supply of the battery energy storage system; the method includes the following steps:

[0012] S1. For each battery pack in the energy storage system, determine multiple discrete power points and test the critical power that causes the battery pack temperature to rise rapidly;

[0013] S2. For each battery pack in the energy storage system, operate it at a critical power and measure the maximum operating time of the battery pack at the critical power as the maximum operating time of the battery pack;

[0014] S3. Design a power supply strategy for the energy storage system based on the external power supply demand of the energy storage system, the critical power of each battery pack in the energy storage system, and the maximum working time of each battery pack in the energy storage system.

[0015] Furthermore, the step S1 includes the following sub-steps:

[0016] S101. For any battery pack in the energy storage system, let the maximum power it can output be P max , according to P max Determine N discrete power points, the power interval between discrete power points ΔP=P max / N, the power value of the nth discrete power point is expressed as:

[0017] P n =nΔP,n=1,2,..,N;

[0018] S102. The output power of the battery pack is adjusted to the nth discrete power point for a duration of t, and the temperature change of the battery pack is measured during the duration, where the temperature change refers to the temperature difference from the beginning of the duration to the end of the duration;

[0019] S103. When n=1, 2, ..., N, repeat step S102 to obtain the temperature changes of N discrete power points, recorded as ΔT1, ΔT2, ..., ΔT N ;

[0020] S104. Set the threshold value τ of the temperature change T , according to ΔT1, ΔT2, ..., ΔT N Select the first one that is greater than τ T The temperature change is calculated, and the power value of the discrete power point corresponding to the temperature change is saved as the critical power of the battery pack, that is, the first power that causes the battery pack temperature to rise rapidly;

[0021] S105. For each battery pack in the energy storage system, steps S101 to S104 are repeated to obtain the critical power of all battery packs.

[0022] Furthermore, the step S2 comprises:

[0023] S201. For any battery pack in the energy storage system, the battery pack will work when the output power is the critical power and start timing;

[0024] S202. The temperature of the battery pack is collected in real time by the temperature sensor and compared with the maximum allowable temperature. When the temperature of the battery pack reaches the maximum allowable temperature, the timing is stopped and the timing result is used as the maximum working time of the battery pack at the critical power and the maximum working time of the battery pack. That is, as long as the working time of the battery pack does not exceed the maximum working time, the battery temperature will not exceed the maximum allowable temperature.

[0025] S203. For each battery pack, repeat steps S201 to S202 to obtain the maximum operating time of each battery pack under the critical power.

[0026] Furthermore, the power supply demand of the energy storage system includes a total power supply power P and a total power supply time T, and the step S3 includes the following sub-steps:

[0027] S301. Assume that the number of battery packs in the energy storage system is M, and the initialization parameter m is M / 3, where M is an integer multiple of 3;

[0028] S302. Randomly select m battery packs from the M battery packs;

[0029] S303. Calculate the average power supply of m battery packs

[0030]

[0031] S304. Compare with the critical power of the selected m battery groups respectively:

[0032] If the critical powers of the selected m battery packs are all greater than Then proceed to step S305;

[0033] If there is at least one battery pack whose critical power is not greater than P among the selected m battery packs, the value of m is updated, and the updated m is equal to the m before the update plus 1, and then the process returns to step S302;

[0034] S305. Determine whether the current m battery packs satisfy the following conditions: the maximum working time of each battery pack is not less than the total power supply time T;

[0035] If satisfied, the output power of the current m battery packs is set to Then start power supply to the outside for time T;

[0036] If not, then for each battery pack whose maximum working time is less than the total power supply time T among the current m battery packs, stop supplying power to the outside after its working time reaches the maximum working time, and select a battery pack with a critical power greater than The battery pack that stops supplying power supplies instead of the battery pack that stops supplying power.

[0037] Further, in step S305, if there are multiple battery packs whose maximum working time is less than the total power supply time T among the current m battery packs, after the multiple battery packs whose maximum working time is less than the total power supply time T stop supplying power, different power packs with a power greater than 100W are required from the remaining Mm battery packs. The battery packs respectively replace the multiple battery packs that have stopped supplying power to continue supplying power.

[0038] The above is a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A temperature-based battery energy storage system power supply method, characterized in that: The battery energy storage system includes a plurality of battery packs, and the plurality of battery packs are used together to realize external power supply of the battery energy storage system; the method includes the following steps: S1. For each battery pack in the energy storage system, determine multiple discrete power points and test the critical power that causes the battery pack temperature to rise rapidly; The step S1 comprises the following sub-steps: S101. For any battery pack in the energy storage system, let the maximum power it can output be P max , according to P max Determine N discrete power points, the power interval between discrete power points ΔP=P max / N, the power value of the nth discrete power point is expressed as: P n =nΔP,n=1,2,..,N; S102. The output power of the battery pack is adjusted to the nth discrete power point for a duration of t, and the temperature change of the battery pack is measured during the duration, where the temperature change refers to the temperature difference from the beginning of the duration to the end of the duration; S103. When n=1, 2, ..., N, repeat step S102 to obtain the temperature changes of N discrete power points, recorded as ΔT1, ΔT2, ..., ΔT N ; S104. Set the threshold value τ of the temperature change T , according to ΔT1, ΔT2, ..., ΔT N Select the first one that is greater than τ T The temperature change is calculated, and the power value of the discrete power point corresponding to the temperature change is saved as the critical power of the battery pack, that is, the first power that causes the battery pack temperature to rise rapidly; S105. For each battery pack in the energy storage system, repeat steps S101 to S104 to obtain the critical power of all battery packs; S2. For each battery pack in the energy storage system, operate it at a critical power and measure the maximum operating time of the battery pack at the critical power as the maximum operating time of the battery pack; S3. Design a power supply strategy for the energy storage system based on the external power supply demand of the energy storage system, the critical power of each battery pack in the energy storage system, and the maximum working time of each battery pack in the energy storage system.

2. A temperature-based battery energy storage system power supply method according to claim 1, characterized in that: The step S2 comprises: S201. For any battery pack in the energy storage system, the battery pack will work when the output power is the critical power and start timing; S202. The temperature of the battery pack is collected in real time by the temperature sensor and compared with the maximum allowable temperature. When the temperature of the battery pack reaches the maximum allowable temperature, the timing is stopped and the timing result is used as the maximum working time of the battery pack at the critical power and the maximum working time of the battery pack. That is, as long as the working time of the battery pack does not exceed the maximum working time, the battery temperature will not exceed the maximum allowable temperature. S203. For each battery pack, repeat steps S201 to S202 to obtain the maximum operating time of each battery pack under the critical power.

3. A temperature-based battery energy storage system power supply method according to claim 1, characterized in that: The power supply demand of the energy storage system includes the total power supply power P and the total power supply time T.

4. A temperature-based battery energy storage system power supply method according to claim 3, characterized in that: The step S3 comprises the following sub-steps: S301. Assume that the number of battery packs in the energy storage system is M, and the initialization parameter m is M / 3, where M is an integer multiple of 3; S302. Randomly select m battery packs from the M battery packs; S303. Calculate the average power supply of m battery packs S304. Compare with the critical power of the selected m battery groups respectively: If the critical powers of the selected m battery packs are all greater than Then proceed to step S305; If among the selected m battery packs, there is at least one critical power not greater than If the battery pack is not updated, the value of m is updated, and the updated value of m is equal to the value of m before the update plus 1, and then the process returns to step S302; S305. Determine whether the current m battery packs satisfy the following conditions: the maximum working time of each battery pack is not less than the total power supply time T; If satisfied, the output power of the current m battery packs is set to Then start power supply to the outside for time T; If not, then for each battery pack whose maximum working time is less than the total power supply time T among the current m battery packs, stop supplying power to the outside after its working time reaches the maximum working time, and select a battery pack with a critical power greater than The battery pack that stops supplying power supplies instead of the battery pack that stops supplying power.

5. A temperature-based battery energy storage system power supply method according to claim 4, characterized in that: In step S305, if there are multiple battery packs whose maximum working time is less than the total power supply time T among the current m battery packs, after these multiple battery packs whose maximum working time is less than the total power supply time T stop supplying power, different power greater than the total power supply time T are required to be selected from the remaining Mm battery packs. The battery packs respectively replace the multiple battery packs that have stopped supplying power to continue supplying power.

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