Pre-charging control method of energy storage battery and main controller

Abstract

The invention discloses a pre-charging control method for an energy storage battery, and the method comprises the steps: controlling a pre-charging switching tube to be closed, so as to enable a battery pack to carry out the pre-charging operation of an inverter bus capacitor through a pre-charging loop; collecting circuit parameters of the pre-charging loop, and setting a target threshold value; the collected circuit parameters are compared with a target threshold value, and when the circuit parameters meet the target threshold value, it is judged that the pre-charging operation is finished; a main loop switch tube is controlled to be closed, and a pre-charging switch tube is controlled to be disconnected; according to the circuit parameters collected in the pre-charging operation, the pre-charging effect of the pre-charging operation is judged, and a judgment result is obtained; and adjusting the circuit parameters of the next pre-charging operation according to the judgment result. On the basis, the circuit safety of the pre-charging operation can be ensured, inverters of different brands and different application scenes are compatible, self-adaptive circuit parameter adjustment is performed according to different conditions, the charging efficiency is greatly improved, and the applicability and universality of the energy storage battery are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of energy storage battery management, and particularly relates to a pre-charging control method of an energy storage battery. BACKGROUND

[0002] In recent years, the photovoltaic energy storage industry has developed rapidly, and the application scenarios of energy storage batteries are increasingly diversified. When an energy storage battery is applied in combination with an inverter, before the main loop of the energy storage battery circuit is closed, the battery and the inverter port need to be pre-charged to a similar voltage value through a pre-charging process, so as to avoid a huge impact current caused by a voltage difference between the battery and the inverter, causing a short circuit of the battery, and existing safety risks such as fire and damage to the battery.

[0003] The existing pre-charging method of an energy storage battery usually adopts fixed circuit parameters. In the process of implementing the embodiments of the application, the inventors found that at least the following problems exist in the prior art: when facing various types and brands of inverters, due to different characteristics of the inverter ports, the pre-charging method with fixed circuit parameters may cause pre-charging failure in some scenarios, thereby limiting the application of the energy storage battery. SUMMARY

[0004] The embodiments of the application mainly solve the technical problem of how to improve the applicability of the pre-charging method of an energy storage battery.

[0005] To solve the above technical problem, one technical solution adopted by the embodiments of the application is to provide a pre-charging control method of an energy storage battery, applied to a pre-charging circuit, wherein the pre-charging circuit comprises a main controller, a battery pack, a main loop, a pre-charging loop and an inverter bus capacitor; the main loop comprises a main loop switch tube, the pre-charging loop comprises a pre-charging switch tube, the main loop switch tube and the pre-charging switch tube are connected in parallel, a first end of the main loop switch tube and a first end of the pre-charging switch tube are connected to a positive electrode of the battery pack; the main loop switch tube and the pre-charging switch tube are connected in series with the inverter bus capacitor, a second end of the main loop switch tube is connected to a positive electrode of the inverter bus capacitor, and a negative electrode of the inverter bus capacitor is connected to a negative electrode of the battery pack; the method comprises: controlling the pre-charging switch tube to be closed, so that the battery pack performs a pre-charging operation on the inverter bus capacitor through the pre-charging loop; collecting circuit parameters of the pre-charging loop, setting a target threshold; comparing the collected circuit parameters with the target threshold, and determining that the pre-charging operation is completed when the circuit parameters meet the target threshold; controlling the main loop switch tube to be closed and the pre-charging switch tube to be disconnected; determining the pre-charging effect of the pre-charging operation according to the circuit parameters collected in the pre-charging operation, and obtaining a determination result; and adjusting the circuit parameters of the next pre-charging operation according to the determination result.

[0006] Optionally, controlling the precharge switch to close so that the battery pack precharges the inverter bus capacitor through the precharge circuit includes: controlling the precharge switch to close; after the precharge switch is closed, controlling the precharge switch to perform a high-frequency switching control operation to enable the battery pack to perform a PWM pulse precharge operation on the inverter bus capacitor in the form of a pulse cycle; and at the end of the PWM pulse precharge operation, controlling the precharge switch to close for a second preset time so that the battery pack performs a precharge operation on the inverter bus capacitor for the second preset time.

[0007] Optionally, the circuit parameters include the voltage of the inverter bus capacitor and the voltage of the battery pack, and the target threshold includes a voltage threshold; comparing the collected circuit parameters with the target threshold, and determining that the pre-charging operation ends when the circuit parameters meet the target threshold, includes: determining that the pre-charging operation ends when the voltage of the inverter bus capacitor exceeds the voltage threshold and the difference between the voltage of the inverter bus capacitor and the voltage of the battery pack is within a preset range.

[0008] Optionally, the circuit parameters include the current of the pre-charging circuit, and the target threshold includes a current threshold; comparing the collected circuit parameters with the target threshold, and determining that the pre-charging operation ends when the circuit parameters meet the target threshold, includes: determining that the pre-charging operation ends when the current of the pre-charging circuit is less than the current threshold.

[0009] Optionally, the circuit parameters include the second preset time; the step of judging the pre-charging effect of the pre-charging operation based on the circuit parameters collected during the pre-charging operation and obtaining a judgment result includes: setting a time interval and a time node for the pre-charging operation; wherein, the time interval is a preset time value interval reflecting the pre-charging state, and the time node is a preset ideal time value of the second preset time; comparing the time interval and the time node with the second preset time to obtain the judgment result of the pre-charging operation.

[0010] Optionally, comparing the time interval and the time node with the second preset time to obtain the determination result of the pre-charging operation includes: if the second preset time is less than the time node, calculating the difference between the time node and the second preset time, and recording it as a first time difference; if the second preset time is greater than or equal to the time node, calculating the difference between the second preset time and the time node, and recording it as a second time difference; if the first time difference is greater than the time interval, determining that the second preset time is too short; if the second time difference is greater than the time interval, determining that the second preset time is too long; if the first time difference or the second time difference is less than or equal to the time interval, determining that the second preset time is normal, and the operation time of the pre-charging operation is normal.

[0011] Optionally, the circuit parameters further include a first preset time corresponding to the PWM pulse pre-charge operation; adjusting the circuit parameters for the next pre-charge operation based on the determination result includes: setting a time optimization coefficient; when the second preset time is too short, determining that the first preset time is too long, then shortening the first preset time in the next pre-charge operation; the magnitude of shortening the first preset time is the product of the first time difference and the time optimization coefficient; when the second preset time is too long, determining that the first preset time is too short, then increasing the first preset time in the next pre-charge operation; the magnitude of increasing the first preset time is the product of the second time difference and the time optimization coefficient.

[0012] Optionally, the pre-charge circuit further includes a pre-charge resistor, which is connected in series with the pre-charge switch and in parallel with the main circuit switch. The circuit parameters include the temperature of the pre-charge resistor. The step of determining the pre-charge effect of the pre-charge operation based on the circuit parameters collected during the pre-charge operation, and obtaining a determination result, includes: setting a temperature threshold for the pre-charge operation; obtaining the highest temperature of the pre-charge resistor during the pre-charge operation based on its temperature; determining that the pre-charge operation is abnormal if the highest temperature is greater than the temperature threshold; and determining that the pre-charge operation is normal if the highest temperature is less than or equal to the temperature threshold. The step of adjusting the circuit parameters for the next pre-charge operation based on the determination result includes: if the pre-charge operation is determined to be abnormal, reducing the duty cycle of the PWM pulse pre-charge operation in the next pre-charge operation; the duty cycle of the PWM pulse pre-charge operation is the percentage of the effective pre-charge time of the PWM pulse pre-charge operation.

[0013] Optionally, if the pre-charge operation is determined to be abnormal, then reducing the duty cycle of the PWM pulse pre-charge operation in the next pre-charge operation includes: setting a temperature optimization coefficient and calculating the temperature difference between the highest temperature and the temperature threshold; obtaining the on-time of the pre-charge switch within one pulse cycle of the high-frequency switch control operation; if the pre-charge operation is determined to be abnormal, then reducing the on-time in the next pre-charge operation; the reduction in the on-time is the product of the temperature difference and the temperature optimization coefficient.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in the embodiments of this application is: to provide a main controller, including: a memory and a processor, the memory being connected to the processor, the processor being used to execute one or more computer programs stored in the memory, and when the processor executes the one or more computer programs, causing the main controller to implement the pre-charge control method for the energy storage battery described in any of the above claims.

[0015] Unlike related technologies, this application provides a pre-charge control method and main controller for energy storage batteries. Through a pre-charge circuit, the battery pack pre-charges the inverter bus capacitor, reducing the safety risks associated with inrush current. By setting a target threshold and combining it with collected circuit parameters, the operating state within the pre-charge circuit can be accurately reflected, the pre-charge operation status can be precisely identified, and the pre-charge effect can be judged. The judgment result is then used for the next pre-charge operation. Instead of manual parameter setting or adjustment each time, it adaptively collects data, performs pre-charge operations, optimizes parameters, and monitors the pre-charge circuit status in real time, significantly improving safety performance and charging efficiency. Furthermore, it is compatible with inverters of different brands and different application scenarios. The adaptive adjustment of circuit parameters through pre-charge operations greatly expands the application range of energy storage batteries, improving their applicability and versatility. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a schematic diagram of a pre-charging circuit corresponding to a pre-charging method for an energy storage battery provided in an embodiment of this application.

[0018] Figure 2 This is a schematic flowchart of a pre-charging method for an energy storage battery provided in an embodiment of this application.

[0019] Figure 3 This is a schematic diagram of the pre-charging operation process of a pre-charging method for an energy storage battery provided in an embodiment of this application.

[0020] Figure 4 This is a schematic diagram of the pre-charging completion status determination process of a pre-charging method for an energy storage battery provided in an embodiment of this application.

[0021] Figure 5 This is a schematic diagram of the pre-charging completion status determination process of a second type of energy storage battery pre-charging method provided in another embodiment of this application.

[0022] Figure 6 This is a schematic diagram of the pre-charging result determination process of a pre-charging method for an energy storage battery provided in an embodiment of this application.

[0023] Figure 7 This is a schematic diagram of the pre-charging result determination process of a pre-charging method for an energy storage battery provided in another embodiment of this application.

[0024] Figure 8 This is a schematic diagram of the pre-charging adaptive adjustment process of a pre-charging method for an energy storage battery provided in an embodiment of this application.

[0025] Figure 9 This is a schematic diagram of the pre-charge adaptive adjustment process of a pre-charge method for an energy storage battery provided in another embodiment of this application.

[0026] Figure 10 This is a schematic diagram of the structure of a main controller provided in an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] It should be noted that, unless otherwise specified, the various features in the embodiments of this application can be combined with each other, all of which are within the protection scope of this application. Furthermore, although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device schematic diagram or the order in the flowchart.

[0029] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0030] In recent years, the photovoltaic energy storage industry has developed rapidly. When energy storage batteries are used in conjunction with inverters, the inverter is charged through a charging circuit. However, if charging is performed directly, a huge inrush current will be generated between the energy storage battery and the inverter, which can easily lead to a short circuit in the energy storage battery, posing safety risks such as fire and battery damage. Therefore, before the main circuit of the energy storage battery charging circuit is closed, a pre-charging operation is required to ensure that the voltages at the energy storage battery and inverter ports are consistent before charging. Specifically, the pre-charging operation is implemented through a pre-charging circuit to achieve the effect of the energy storage battery charging the inverter. As application scenarios become increasingly diversified, energy storage batteries are no longer limited to pairing with inverters from a single brand, but are instead paired with inverters from different manufacturers, models, and with varying parameters. Simultaneously, complex application scenarios such as multiple inverters operating in parallel are also on the rise, placing higher demands on the compatibility and flexibility of energy storage batteries and inverters. Current pre-charging operations typically use uniform parameters, which lacks applicability and cannot adapt to inverters with different parameters.

[0031] Based on these issues, this application proposes a pre-charge control method for energy storage batteries, applied to a pre-charge circuit, such as... Figure 1 As shown, the pre-charge circuit is the circuit medium for the energy storage battery to pre-charge and charge the inverter. The pre-charge circuit includes the main controller, battery pack, main circuit, pre-charge circuit, and inverter bus capacitor. The main circuit is the primary charging circuit, including a main circuit switch. Controlling the main circuit switch's opening and closing controls the charging circuit's on / off state. The pre-charge circuit is the pre-charging circuit, including a pre-charge switch. Controlling the pre-charge switch's opening and closing controls the pre-charge circuit's on / off state. The charging circuit and pre-charge circuit are connected in parallel. Specifically, the main circuit switch and the pre-charge switch are connected in parallel, with their first terminals connected to the positive terminal of the battery pack. Both are connected in series with the inverter bus capacitor, which is connected in series in the main pre-charge circuit. The negative terminal of the inverter bus capacitor is connected to the negative terminal of the battery pack. The inverter bus capacitor is a key energy storage component inside the inverter used to stabilize the DC bus voltage and buffer electrical energy. The voltage across its terminals is directly equivalent to the voltage output by the battery pack, and it is the core charging object in the pre-charging process.

[0032] The pre-charging circuit proposed in this application embodiment is merely an example used to implement the pre-charging control method for the energy storage battery proposed in this application embodiment, and does not specifically limit the component configuration, connection relationship, and operation mode of the pre-charging circuit.

[0033] In some embodiments of this application, based on Figure 1 The pre-charging circuit shown is as follows: Figure 2 As shown, the method includes, but is not limited to, the following steps: 101: Control the pre-charge switch to close so that the battery pack pre-charges the inverter bus capacitor through the pre-charge circuit.

[0034] After the pre-charge switch is closed, the pre-charge circuit begins pre-charging. During the pre-charging process of the inverter bus capacitor, the pre-charge circuit continuously generates heat. If the pre-charging operation continues uninterrupted, with the pre-charge switch continuously closed, the battery pack continuously charges the inverter bus capacitor with a large current. When the inverter bus capacitor has a large capacitance, the overall pre-charging operation time will be significantly prolonged, potentially damaging the components in the circuit. Therefore, an optimized pre-charging operation is needed to protect the pre-charge circuit.

[0035] In some embodiments, such as Figure 3 As shown, the step of pre-charging the battery pack to the inverter bus capacitor through the pre-charge circuit includes: 1011: After the precharge switch is closed, the precharge switch is controlled to perform a high-frequency switching control operation, so that the battery pack performs a PWM pulse precharge operation on the inverter bus capacitor in the form of a pulse cycle. 1012: When the PWM pulse pre-charge operation ends, control the pre-charge switch to close for a second preset time, so that the battery pack performs a pre-charge operation on the inverter bus capacitor for the second preset time.

[0036] By completing the pre-charging operation in a coordinated manner through steps 1011 and 1012, the pre-charging operation can be made safe and efficient.

[0037] Specifically, the core of the PWM (Pulse Width Modulation) pre-charge operation is to control the temperature in the pre-charge circuit. High-frequency switching control is achieved by alternately turning the pre-charge switch on and off within one pulse cycle. For example, with a pulse period of 1ms, the on cycle is 0.5ms and the off cycle is 0.5ms. This pulsed high-frequency switching control operation results in a pulsed current in the circuit, which then charges the inverter bus capacitor in the form of a pulsed current. When the switch is on, the inverter bus capacitor absorbs energy, and its voltage rises slightly. When the switch is off, the inverter bus capacitor voltage remains stable, and the pre-charge circuit stops working and does not continue to generate heat. By reducing the effective value of the current in the pre-charge circuit through the PWM pulse pre-charge operation, the pre-charge circuit will not generate heat for a prolonged period, thus preventing overheating and significantly increasing the safety factor.

[0038] Understandably, if a single PWM pulse pre-charge operation is used, although it can achieve the temperature control effect of the pre-charge circuit, the effective charging time of the PWM pulse pre-charge is not high due to the reduced effective current value. This results in a slow rise in the voltage of the inverter bus capacitor, and the overall pre-charge operation takes too long, which affects the user experience and may lead to insufficient charging.

[0039] Specifically, this embodiment employs a two-stage pre-charging operation. After completing the PWM pulse pre-charging operation in step 1011, step 1012 is immediately executed, continuously controlling the pre-charging switch to remain closed for a second preset time. The core function is to replenish energy during the pre-charging operation in the pre-charging circuit. At this time, the switch no longer performs high-frequency switching operations; instead, it remains closed, allowing the battery pack to continuously charge the inverter bus capacitor through the pre-charging circuit. During step 1012, the inverter bus capacitor has already accumulated a certain voltage through the PWM pulse pre-charging operation in step 1011. At this point, the voltage to be pre-charged is relatively small, the charging circuit current decreases, and there is no safety risk of excessive heat generation. Continuous pre-charging can quickly complete the remaining pre-charging operation, solving the problem of low efficiency in a single PWM pulse pre-charging operation.

[0040] In this application embodiment, a PWM pulse pre-charge operation is used to solve the heat generation problem of the pre-charge circuit, and a continuous pre-charge operation is used to solve the problems of pre-charge efficiency and pre-charge sufficiency. The two steps work together to complete the pre-charge operation.

[0041] 102: Collect the circuit parameters of the pre-charge circuit and set the target threshold.

[0042] The circuit parameters are quantifiable physical quantities in the pre-charge circuit, reflecting the real-time status of the battery, pre-charge circuit, and inverter during the pre-charge operation; the target threshold is a pre-set critical threshold based on requirements such as safety, compatibility, and charging adequacy, and serves as the basis for judging whether each state in the pre-charge circuit meets the pre-charge expectation.

[0043] 103: Compare the collected circuit parameters with the target threshold. When the circuit parameters meet the target threshold, determine that the pre-charging operation has ended.

[0044] In some embodiments, the circuit parameters include the voltage of the inverter bus capacitor. and the voltage of the battery pack The target threshold includes a voltage threshold. For example... Figure 4 As shown, comparing the collected circuit parameters with the target threshold, and determining the end of the pre-charging operation when the circuit parameters meet the target threshold, includes: 10301: Obtain the voltage of the inverter bus capacitor. and the voltage of the battery pack Set the voltage threshold and preset range; 10302: Calculate the voltage of the inverter bus capacitor. With the voltage of the battery pack The difference ; 10303: The voltage of the inverter bus capacitor Compare with the voltage threshold and the difference Compare with a preset range. If the voltage of the inverter bus capacitor... Exceeding the voltage threshold and the difference If the preset range is met, proceed to step 10304; otherwise, proceed to step 10305.

[0045] 10304: Determine the voltage of the inverter bus capacitor. Once the objective is met, the pre-charging operation ends.

[0046] 10305: Determine the voltage of the inverter bus capacitor. If the target is not met, the pre-charging operation is not completed and will continue.

[0047] It is understandable that the voltage of the inverter bus capacitor... This is the voltage output by the battery pack, the voltage across the inverter bus capacitor, and the target voltage value to be achieved during the pre-charging operation. The ultimate ideal target is the voltage of the inverter bus capacitor. With the voltage of the battery pack Consistent. Battery pack voltage. The voltages on both sides of the battery pack are the output voltages of the energy storage batteries themselves and also the reference voltages for pre-charging operations. The voltage threshold is the target voltage value, i.e., the preset voltage of the inverter bus capacitor. The target value is set as a critical value for judging whether the inverter bus capacitor is close to the battery voltage, for example: battery pack voltage. 90%. The preset range is the final allowable difference. Upper limit.

[0048] Specifically, during the pre-charging operation, the voltage of the inverter bus capacitor is collected. and battery pack voltage And calculate the difference between the two. Compare the voltages of the inverter bus capacitors. And voltage threshold, when the voltage of the inverter bus capacitor Exceeding the voltage threshold, and the difference When the voltage is within the preset range, determine the voltage of the inverter bus capacitor at this time. The target voltage value has been reached, and the voltage of the battery pack is... Approaching completion of the pre-charge operation requires two conditions to be met simultaneously. This is because the essence of pre-charge is to level the voltage of the inverter bus capacitors. With the voltage of the battery pack The voltage difference is the root cause of inrush current in a circuit, so controlling the voltage difference is the core operation to avoid excessive inrush current.

[0049] In some embodiments, the circuit parameters include the current of the pre-charging circuit. The target threshold includes a current threshold; such as Figure 5 As shown, comparing the collected circuit parameters with the target threshold, and determining the end of the pre-charging operation when the circuit parameters meet the target threshold, includes: 10311: Obtain the current of the pre-charge circuit. Set the current threshold.

[0050] 10312: The current of the pre-charging circuit Compared with the current threshold, if the current of the pre-charging circuit... If the current is less than the current threshold, proceed to step 10313; if the current of the pre-charging circuit is... If the current is greater than or equal to the current threshold, proceed to step 10314.

[0051] 10313: Determine the current of the pre-charging circuit. The target has been met, and the pre-charging operation has ended.

[0052] 10314: Determine the current of the pre-charging circuit If the target is not met, the pre-charging operation is not completed and will continue.

[0053] Understandably, the current in the pre-charging circuit... This refers to the current flowing through the pre-charge circuit during the pre-charge operation, and it is a core indicator reflecting the pre-charge state. The current threshold is the target current value, i.e., the preset current of the pre-charge circuit. The steady-state current value is set as the critical current for determining whether the pre-charging operation is nearing its end. If it is less than this value, it indicates that the pre-charging is close to completion.

[0054] Specifically, during the pre-charging operation, the current of the pre-charging circuit is collected. At the start of the pre-charge operation, the voltage of the inverter bus capacitor... The voltage difference is 0. The current is very large; according to Ohm's law, the current in the pre-charging circuit is... Extremely high. As the pre-charge operation proceeds, the voltage of the inverter bus capacitor... Gradually increase, voltage difference The current in the pre-charging circuit decreases at this time. It also decreases accordingly. The voltage difference decreases as the pre-charge operation nears its end. The current in the pre-charging circuit decreases as it gets smaller. It also gets smaller and smaller, as the current in the pre-charging circuit... When the current is below the preset current threshold, it indicates that the pre-charging is nearing completion, and there is no threat of a large current surge. The current in the pre-charging circuit... The magnitude of this directly reflects the pre-charge intensity and the current in the pre-charge circuit. The large reading indicates that pre-charging is still proceeding rapidly and the capacitor is not fully charged; the current in the pre-charging circuit... The instructions state that the pre-charging process is nearing completion, and at this point, closing the main circuit will not cause damage to the main circuit switch or battery due to a large current surge.

[0055] 104: Control the main circuit switch to close, and simultaneously control the precharge switch to open.

[0056] It is understandable that step 104 is the switching step between pre-charging operation and normal charging operation. Disconnecting the pre-charging switch cuts off the pre-charging circuit, indicating the end of the pre-charging operation and that the pre-charging circuit will no longer operate. Closing the main circuit switch opens the main charging circuit, indicating the start of the charging operation. Both steps must be performed simultaneously. If the main circuit switch is closed beforehand and the pre-charging switch is closed later, the pre-charging circuit may be short-circuited, resulting in a large short circuit. If the pre-charging switch is closed beforehand and the main circuit switch is closed later, the inverter bus capacitor voltage may drop sharply, thus increasing the voltage difference during charging. The current increases again, generating a large inrush current. Therefore, by performing a synchronized switching operation, circuit risks are avoided, and a smooth switching between pre-charging and charging operations is achieved.

[0057] 105: Based on the circuit parameters collected during the pre-charging operation, the pre-charging effect of the pre-charging operation is determined, and a determination result is obtained; In some embodiments, the circuit parameters include the second preset time T2; such as Figure 6 As shown, the step of judging the pre-charging effect of the pre-charging operation based on the circuit parameters collected during the pre-charging operation, and obtaining the judgment result, includes: 10501: Obtain the second preset time T2, and set the time interval and time node T3 of the pre-charging operation.

[0058] 10502: Compare the time node with the second preset time T2. If the second preset time T2 is less than the time node T3, execute steps 10503 and 10504; if the second preset time T2 is greater than or equal to the time node, execute step 10507. 10503: Calculate the difference T0 between the time node T3 and the second preset time T2, and record it as the first time difference; 10504: Compare the first time difference with the time interval. If the first time difference is greater than the time interval, proceed to step 10505; if the first time difference is less than or equal to the time interval, proceed to step 10506.

[0059] 10505: It is determined that the second preset time T2 is too short, and the operation time of the pre-charging operation is abnormal.

[0060] 10506: It is determined that the second preset time T2 is normal, and the operation time of the pre-charging operation is normal.

[0061] 10507: Calculate the difference T0 between the second preset time T2 and the time node T3, and record it as the second time difference; 10508: Compare the second time difference with the time interval. If the second time difference is greater than the time interval, proceed to step 10509; if the second time difference is less than or equal to the time interval, proceed to step 10506.

[0062] 10509: It is determined that the second preset time T2 is too long, and the operation time of the pre-charging operation is abnormal.

[0063] It should be noted that the second preset time T2 is the time from the end of the PWM pulse pre-charge operation to the completion of the pre-charge operation; the time interval is a preset time value interval reflecting the pre-charge state, which is a fluctuation threshold, to allow the second preset time T2 to deviate from the target value error range, and to avoid misjudging the pre-charge result due to small fluctuations; the time node T3 is the preset ideal time value of the second preset time T2, which is set based on a large number of inverter adaptation tests to preset an ideal continuous pre-charge time that takes into account both charging efficiency and safety.

[0064] It is understandable that fixing the duration of the PWM pulse pre-charge operation will result in different charging effects depending on the inverter: different inverters have significantly different bus capacitor capacities, requiring longer PWM pulse pre-charge operations to charge the capacitor to near the battery pack voltage, while smaller capacitors require less time. A fixed duration makes it impossible to determine whether the current PWM pulse pre-charge operation is suitable for the current inverter, i.e., whether the PWM pulse pre-charge operation is sufficient. The more sufficient the PWM pulse pre-charge operation, the higher the voltage charged to the bus capacitor during this stage, resulting in less voltage supplementation needed during the continuous pre-charge stage, and a shorter second preset time T2, and vice versa. Therefore, the second preset time T2 is a core indicator reflecting the effectiveness of the PWM pulse pre-charge operation that can be obtained without additional sensors. Furthermore, judging solely by the length of the second preset time T2 is prone to misjudgment due to fluctuations. Therefore, a common judgment of the time interval is introduced, placing the target value within an acceptable error range. This allows for determining whether the second preset time T2 meets the standard while avoiding misjudgments caused by small fluctuations.

[0065] Specifically, a time node that has been extensively tested and verified is first preset, and a time interval is set to account for factors such as slight differences in inverter capacitors, to avoid judging an anomaly based on a slight deviation from the second preset time T2. Then, the difference between the second preset time T2 and the time node T3 is calculated, and the result is further compared based on the difference. If the second preset time T2 is larger than the time node T3, it means that the second preset time T2 is longer. If this is within the allowable range, it means the result is normal. If it exceeds the allowable range, it means that the second preset time T2 is too long, indicating that the PWM pulse pre-charge operation is insufficient, and the inverter bus capacitor is not fully charged during this stage. If the second preset time T2 is smaller than the time node T3, it means that the second preset time T2 is shorter. If this is within the allowable range, it means the result is normal. If it exceeds the allowable range, it means that the second preset time T2 is too short, indicating that the PWM pulse pre-charge operation time is too long.

[0066] By using dual judgment criteria, the adaptability of the PWM pulse pre-charge operation to the inverter can be accurately identified, avoiding insufficient pre-charge efficiency or redundant pre-charge working time, improving system efficiency and stability while enhancing the accuracy of the judgment.

[0067] In some embodiments, such as Figure 1 As shown, the pre-charge circuit further includes a pre-charge resistor, which is connected in series with the pre-charge switch and in parallel with the main circuit switch; the circuit parameters include the temperature of the pre-charge resistor; as shown... Figure 7 As shown, the step of judging the pre-charging effect of the pre-charging operation based on the circuit parameters collected during the pre-charging operation, and obtaining the judgment result, includes: 10511: Obtain the temperature of the pre-charge resistor to obtain the highest temperature of the pre-charge resistor during the pre-charge operation. Set the temperature threshold for the pre-charging operation; 10512: The highest temperature Compare with the temperature threshold. If the highest temperature... If the temperature exceeds the stated temperature threshold, proceed to step 10513; if the highest temperature... If the temperature is less than or equal to the stated temperature threshold, then proceed to step 10514.

[0068] 10513: Determine the highest temperature of the pre-charge resistor during the pre-charge operation. If the value is too high, the pre-charge operation will malfunction.

[0069] 10514: Determine the highest temperature of the pre-charge resistor during the pre-charge operation. Normal, the pre-charging operation is normal.

[0070] It is understood that during the pre-charging operation in the pre-charging circuit, current flows through the pre-charging resistor, causing it to generate heat and its temperature to rise. The temperature of the pre-charging resistor is a direct reflection of the heat generated. Throughout the pre-charging process, the pre-charging resistor will reach its highest temperature. Excessive temperature can lead to the risk of the pre-charging resistor burning out, thus causing safety issues for the entire pre-charging circuit. Therefore, a temperature threshold is set. This temperature threshold represents the highest permissible operating temperature of the pre-charging resistor during pre-charging. Exceeding this temperature threshold poses a risk to the pre-charging resistor. The temperature threshold is set as the product of the maximum permissible operating temperature of the pre-charging resistor and a preset proportional coefficient. For example, the preset proportional coefficient is 0.7, leaving a safety margin of 0.3 to ensure the safety of the pre-charging circuit.

[0071] Specifically, the operating temperature of the pre-charging resistor during the pre-charging operation in the pre-charging circuit is obtained, and the highest temperature is obtained by analyzing the collected operating temperature. The highest temperature Compare with the temperature threshold. If the highest temperature If the temperature is less than or equal to the temperature threshold, it indicates that the pre-charge resistor is operating safely and there is no risk of burnout due to excessive current and temperature rise; if the maximum temperature is... If the temperature exceeds the threshold, it indicates that the pre-charge resistor is overheating and approaching the maximum allowable operating temperature, posing a safety risk of burnout. In this case, the pre-charge operation is abnormal.

[0072] By monitoring the temperature of the pre-charge resistor, the risk of overheating of the pre-charge resistor can be resolved. Even in situations such as multiple inverters operating in parallel or excessively large bus capacitors, safety accidents such as pre-charge resistor burnout and battery fires will not occur, thus extending the lifespan of the core component, the pre-charge resistor. At the same time, the status of the pre-charge operation is also monitored.

[0073] 106: Adjust the circuit parameters for the next pre-charging operation based on the determination result.

[0074] In some embodiments, the circuit parameters further include a first preset time T1 corresponding to the PWM pulse pre-charge operation, after step 10505 or step 10509 is executed, such as Figure 8 As shown, adjusting the circuit parameters for the next pre-charging operation based on the determination result includes: 10601: Obtain the first preset time T1 and set the time optimization coefficient. If step 10505 has been executed, then execute step 10602; if step 10509 has been executed, then execute step 10603.

[0075] 10602: If the first preset time T1 is determined to be too long, the first preset time T1 shall be shortened in the next pre-charging operation.

[0076] 10603: If the first preset time T1 is determined to be too short, the first preset time T1 shall be increased in the next pre-charging operation.

[0077] It should be noted that the first preset time T1 represents the duration of the PWM pulse pre-charge operation. Shortening the first preset time T1 by the amount of reduction is the product of the first time difference and the time optimization coefficient; increasing the first preset time T1 by the amount of increase is the product of the second time difference and the time optimization coefficient. The time optimization coefficient is a proportional factor controlling the adjustment range of the first preset time T1. Its purpose is to prevent excessive adjustment leading to errors and loss of adjustment effect. It is set as a preset fixed proportional coefficient, determined based on extensive inverter adaptation testing, to ensure that the adjustment of the first preset time T1 is smooth and accurate.

[0078] It is understandable that the first preset time T1 and the second preset time T2 have a strong negative correlation. The longer the first preset time T1, the more electricity the battery pack charges the inverter bus capacitor during the PWM pulse pre-charge operation phase, and the less electricity needs to be added during the continuous pre-charge phase, resulting in a shorter second preset time T2; conversely, the shorter the first preset time T1, the less electricity needs to be added during the continuous pre-charge phase. By collecting the duration of the continuous pre-charge, the complex PWM pulse pre-charge problem can be reflected more conveniently and accurately. At the same time, a time optimization coefficient is introduced to adjust the magnitude of the change, preventing excessive adjustment from causing parameter oscillations.

[0079] Specifically, if the first preset time T1 is too long, it is considered redundant. In this case, the calculated first time difference is multiplied by a time optimization coefficient, and the resulting first preset time T1 is shortened. If the first preset time T1 is too short, it is considered insufficient. In this case, the calculated second time difference is multiplied by a time optimization coefficient, and the resulting first preset time T1 is increased. Both shortening and increasing the first preset time T1 are aimed at making the pre-charging operation more accurate, efficient, and safe, while also improving the user experience.

[0080] In some embodiments, after step 10513 is performed, as follows Figure 9 As shown, adjusting the circuit parameters for the next pre-charging operation based on the determination result includes: 10611: Obtain the on-time of the precharge switch tube within one pulse cycle of the high-frequency switch control operation; 10612: Set the temperature optimization coefficient and calculate the maximum temperature. The temperature difference T between the stated temperature threshold and the stated temperature value. 10613: Reduce the conduction duration during the next pre-charge operation.

[0081] It should be noted that the pulse period refers to the complete cycle time of one on-off cycle during the PWM pulse pre-charge operation. The on-time of the pre-charge switch is the time during which the pre-charge switch is turned on for charging within one pulse period. Optimizing the pre-charge operation based on the temperature of the pre-charge resistor means optimizing the duty cycle of the PWM pulse pre-charge operation. The duty cycle of the PWM pulse pre-charge operation is the percentage of the effective pre-charge time of the PWM pulse pre-charge operation, and this percentage is fed back and adjusted by the on-time of the pre-charge switch. The temperature optimization coefficient is a proportional standard for controlling the adjustment range of the on-time. It is set as a preset fixed coefficient, determined based on the characteristics of the pre-charge resistor and the pulse period, to ensure that the adjustment range matches the temperature. The reduction in the on-time is the product of the temperature difference T and the temperature optimization coefficient.

[0082] It's understandable that the duty cycle is essentially the ratio of the on-time within a pulse period to the total period. With a fixed pulse period, adjusting the on-time is equivalent to precisely adjusting the duty cycle. For example, if the pulse period is 1ms and the on-time is 0.5ms, the duty cycle is 50%. By controlling the on-time, the duty cycle can be adjusted precisely and slightly, providing a convenient and intuitive quantification method. By reducing the duty cycle of the pre-charge switch, the on-time within one pulse period is reduced, preventing the pre-charge resistor from overheating and burning out during PWM pulse pre-charge operations due to excessively long and frequent on-time. This allows for temperature control and ensures the stability of the pre-charge operation.

[0083] In summary, unlike related technologies, this application provides a pre-charge control method for energy storage batteries. By using a pre-charge circuit, the battery pack pre-charges the inverter bus capacitor, reducing the safety risks associated with inrush current. By setting a target threshold and combining it with collected circuit parameters, the method accurately reflects the operating state within the pre-charge circuit, precisely identifies the pre-charge operation, and determines the pre-charge effect. The determination result is then used for the next pre-charge operation. Instead of manual parameter setting or adjustment each time, the method adaptively collects data, performs pre-charge operations, optimizes parameters, and monitors the pre-charge circuit status in real time, significantly improving safety and charging efficiency. Furthermore, it is compatible with inverters from different brands and in different application scenarios. The adaptive adjustment of circuit parameters through pre-charge operations greatly expands the application range of energy storage batteries, enhancing their applicability and versatility.

[0084] Please see Figure 10 , Figure 10This is a schematic diagram of a main controller provided in an embodiment of this application. The main controller 30 includes one or more processors 31 and a memory 32. The memory 32 is connected to one or more processors 31, for example, via a bus.

[0085] Processor 31 is configured to support the main controller 30 in performing the corresponding functions in the methods described in the above method embodiments. Processor 31 may be a central processing unit (CPU), a network processor (NP), a hardware chip, or any combination thereof. The aforementioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The aforementioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0086] Memory 32 is used to store program code, etc. Memory 32 may include volatile memory (VM), such as random access memory (RAM); memory 32 may also include non-volatile memory (NVM), such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); memory 32 may also include combinations of the above types of memory.

[0087] The memory 32 can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the pre-charge control method for the energy storage battery in the embodiments of this application. The processor 31 executes various functional applications and data processing of the pre-charge control method for the energy storage battery by running the non-volatile software programs, instructions, and modules stored in the memory 32, that is, it realizes the functions of each module or unit of the pre-charge control method for the energy storage battery provided in the above method embodiments.

[0088] The memory 32 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and applications required for at least one function. The data storage area may store data created based on the use of the immersive meeting implementation device, etc. In some embodiments, the memory 32 may include remotely located memories 32 relative to the processor 31, which can be connected via a network to a precharge control identification device for the energy storage battery. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0089] The one or more modules are stored in the memory 32. When executed by the one or more processors 31, they perform the pre-charge control method for the energy storage battery in any of the above method embodiments. For example, they perform the method steps described in the above method embodiments to realize the functions of the modules described in the above device embodiments.

[0090] The main controller in this application embodiment can be an MCU or a DSP / FPGA chip, etc.

[0091] This application provides a non-volatile computer-readable storage medium storing computer-executable instructions that are executed by one or more processors 31, for example... Figure 10 One of the processors 31 can be configured to execute the pre-charge control method for the energy storage battery in any of the above method embodiments, for example, to execute the method described above. Figure 2 Steps 101 to 106 in the method are as follows. Figure 3 Steps 1011 to 1012 in the method are as follows. Figure 4 Method steps 10301 to 10305, Figure 5 Method steps 10311 to 10314 in the text Figure 6 Method steps 10501 to 10509 in the text Figure 7 Method steps 10511 to 10514, Figure 8 Method steps 10601 to 10603, Figure 9 Steps 10611 to 10613 in the method.

[0092] This application provides a computer program product, which includes a computer program stored on a non-volatile computer-readable storage medium. The computer program includes program instructions, which, when executed by the main controller, enable the main controller to perform any of the above-described method embodiments. Figure 2 Steps 101 to 106 in the method are as follows. Figure 3Steps 1011 to 1012 in the method are as follows. Figure 4 Method steps 10301 to 10305, Figure 5 Method steps 10311 to 10314 in the text Figure 6 Method steps 10501 to 10509 in the text Figure 7 Method steps 10511 to 10514, Figure 8 Method steps 10601 to 10603, Figure 9 Steps 10611 to 10613 in the method.

[0093] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0094] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A pre-charge control method for an energy storage battery, applied to a pre-charge circuit, characterized in that, The pre-charge circuit includes a main controller, a battery pack, a main circuit, a pre-charge circuit, and an inverter bus capacitor. The main circuit includes a main circuit switch, and the pre-charge circuit includes a pre-charge switch. The main circuit switch and the pre-charge switch are connected in parallel. The first terminal of the main circuit switch and the first terminal of the pre-charge switch are connected to the positive terminal of the battery pack. The main circuit switch and the pre-charge switch are connected in series with the inverter bus capacitor. The second terminal of the main circuit switch is connected to the positive terminal of the inverter bus capacitor, and the negative terminal of the inverter bus capacitor is connected to the negative terminal of the battery pack. The method includes: The precharge switch is controlled to close, so that the battery pack precharges the inverter bus capacitor through the precharge circuit. Collect the circuit parameters of the pre-charge circuit and set the target threshold; The collected circuit parameters are compared with the target threshold. When the circuit parameters meet the target threshold, the pre-charging operation is determined to be over. The main circuit switch is closed, and the precharge switch is opened simultaneously. Based on the circuit parameters collected during the pre-charging operation, the pre-charging effect of the pre-charging operation is determined, and a determination result is obtained. The circuit parameters for the next pre-charging operation are adjusted based on the determination result.

2. The method according to claim 1, characterized in that, The control of closing the pre-charge switch to allow the battery pack to pre-charge the inverter bus capacitor through the pre-charge circuit includes: Control the closure of the precharge switch transistor; After the precharge switch is closed, the precharge switch is controlled to perform a high-frequency switching control operation, so that the battery pack performs a PWM pulse precharge operation on the inverter bus capacitor in the form of a pulse cycle. When the PWM pulse pre-charge operation ends, the pre-charge switch is controlled to close for a second preset time, so that the battery pack performs a pre-charge operation on the inverter bus capacitor for the second preset time.

3. The method according to claim 1, characterized in that, The circuit parameters include the voltage of the inverter bus capacitor and the voltage of the battery pack, and the target threshold includes a voltage threshold. The step of comparing the collected circuit parameters with the target threshold, and determining that the pre-charging operation ends when the circuit parameters meet the target threshold, includes: When the voltage of the inverter bus capacitor exceeds the voltage threshold, and the difference between the voltage of the inverter bus capacitor and the voltage of the battery pack is within a preset range, the pre-charging operation is determined to be over.

4. The method according to claim 1, characterized in that, The circuit parameters include the current of the pre-charging circuit, and the target threshold includes a current threshold. The step of comparing the collected circuit parameters with the target threshold, and determining the end of the pre-charging operation when the circuit parameters meet the target threshold, includes: When the current in the pre-charging circuit is less than the current threshold, the pre-charging operation is determined to be over.

5. The method according to claim 2, characterized in that, The circuit parameters include the second preset time; The step of determining the pre-charging effect of the pre-charging operation based on the circuit parameters collected during the pre-charging operation, and obtaining a determination result, includes: The time interval and time node of the pre-charging operation are set; wherein, the time interval is a preset time value interval reflecting the pre-charging state, and the time node is the ideal time value of the second preset time. The time interval and the time node are compared with the second preset time to obtain the determination result of the pre-charging operation.

6. The method according to claim 5, characterized in that, The step of comparing the time interval and the time node with the second preset time to obtain the determination result of the pre-charging operation includes: If the second preset time is less than the time node, calculate the difference between the time node and the second preset time, and record it as the first time difference; if the second preset time is greater than or equal to the time node, calculate the difference between the second preset time and the time node, and record it as the second time difference. If the first time difference is greater than the time interval, the second preset time is determined to be too short; if the second time difference is greater than the time interval, the second preset time is determined to be too long. If the first time difference or the second time difference is less than or equal to the time interval, then the second preset time is determined to be normal, and the operation time of the pre-charging operation is normal.

7. The method according to claim 6, characterized in that, The circuit parameters also include the first preset time corresponding to the PWM pulse precharge operation. The step of adjusting the circuit parameters for the next pre-charging operation based on the determination result includes: Set the time optimization factor; If the second preset time is too short, the first preset time is determined to be too long, and the first preset time is shortened in the next pre-charging operation; the amount of shortening the first preset time is the product of the first time difference and the time optimization coefficient; If the second preset time is too long, the first preset time is determined to be too short. Then, the first preset time is increased in the next pre-charging operation. The increase in the first preset time is the product of the second time difference and the time optimization coefficient.

8. The method according to claim 2, characterized in that, The pre-charge circuit also includes a pre-charge resistor, which is connected in series with the pre-charge switch and in parallel with the main circuit switch; the circuit parameters include the temperature of the pre-charge resistor; The step of determining the pre-charging effect of the pre-charging operation based on the circuit parameters collected during the pre-charging operation, and obtaining a determination result, includes: Set the temperature threshold for the pre-charge operation; The highest temperature of the pre-charging resistor during the pre-charging operation is obtained based on the temperature of the pre-charging resistor. If the highest temperature is greater than the temperature threshold, the pre-charging operation is determined to be abnormal; if the highest temperature is less than or equal to the temperature threshold, the pre-charging operation is determined to be normal. The step of adjusting the circuit parameters for the next pre-charging operation based on the determination result includes: If the pre-charge operation is determined to be abnormal, the duty cycle of the PWM pulse pre-charge operation will be reduced in the next pre-charge operation. The duty cycle of the PWM pulse precharge operation is the percentage of the effective precharge time of the PWM pulse precharge operation.

9. The method according to claim 8, characterized in that, If the pre-charge operation is determined to be abnormal, then in the next pre-charge operation, the duty cycle of the PWM pulse pre-charge operation is reduced, including: Set a temperature optimization coefficient and calculate the temperature difference between the highest temperature and the temperature threshold. Obtain the on-time of the precharge switch transistor within one pulse cycle of the high-frequency switch control operation; If the pre-charging operation is determined to be abnormal, the conduction time will be reduced in the next pre-charging operation; the reduction in the conduction time is the product of the temperature difference and the temperature optimization coefficient.

10. A main controller, characterized in that, include: A memory and a processor, the memory being connected to the processor, the processor being configured to execute one or more computer programs stored in the memory, wherein, when executing the one or more computer programs, the processor causes the main controller to implement the pre-charge control method for the energy storage battery as described in any one of claims 1 to 9.

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