Control system of energy storage system

Abstract

The utility model discloses a control system of an energy storage system, which comprises an upper computer and a battery monitoring unit, and the battery monitoring unit is in communication connection with the upper computer and is used for monitoring the voltage of a battery cell in the energy storage system; each battery monitoring unit comprises a microcontroller and a discharging unit, the upper computer is in communication connection with the microcontroller and sends the voltage of a monitored target battery cell to the microcontroller, and the microcontroller transmits the voltage monitoring result of the target battery cell back to the upper computer; the discharging unit is electrically connected with the microcontroller and the target battery cell, and the discharging unit receives a control signal of the microcontroller and discharges the target battery cell; the control signal is issued by the microcontroller after receiving an equalization instruction of the upper computer, the equalization instruction is obtained when the output result is 1 after the upper computer receives the voltage monitoring result, and the output result is 1 which indicates that the target battery cell is in a floating charge state and the voltage of the target battery cell is greater than a preset threshold value. The utility model aims to maintain the balance state of the battery voltage and further prolong the service life of the battery.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery, more particularly to a control system of energy storage system. BACKGROUND

[0002] The battery group used in the transformer substation of the power system is usually composed of 110-120 batteries, and due to the manufacturing and other reasons, individual batteries will be damaged in advance when most of the batteries are in good condition. Because the characteristics of new and old batteries are inconsistent, when they are connected into the original battery group, the float current for maintaining the terminal voltage of the old battery will make the terminal voltage of the new battery exceed the allowable value, resulting in serious water loss and anode plate damage of the new battery, so the new battery often appears to be damaged soon after replacement.

[0003] In the related art, the method of replacing the damaged battery is mainly used for the above phenomenon, and a shunt resistor is connected in parallel across the two ends of the newly replaced battery. However, this method requires accurate calculation of the resistance value of the shunt resistor, and the resistance value is usually not in the resistance value of the resistance renard series, and it is very troublesome to customize the resistance and the maintenance personnel need to monitor the voltage of the new battery and adjust the resistance value frequently, which has great technical difficulty and requires a lot of work. Therefore, it is necessary to provide a control system of energy storage system, which can maintain the balanced state of the battery voltage and prolong the service life of the battery. SUMMARY

[0004] Therefore, the utility model provides a control system of energy storage system, which can maintain the balanced state of the battery voltage and prolong the service life of the battery.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme:

[0006] A control system of energy storage system, the control system comprises an upper computer and at least one battery monitoring unit, wherein:

[0007] Each battery monitoring unit is in communication connection with the upper computer and monitors the voltage of at least one battery cell in the energy storage system;

[0008] Each battery monitoring unit comprises a microcontroller and a discharging unit, wherein:

[0009] The upper computer is in communication connection with the microcontroller and sends the voltage of the target battery cell to be monitored to the microcontroller, the target battery cell being the currently monitored battery cell, and the microcontroller returns the voltage monitoring result of the target battery cell to the upper computer;

[0010] The discharge unit is electrically connected with the microcontroller and the target battery cell, and the discharge unit receives a control signal of the microcontroller to discharge the target battery cell; wherein the control signal is sent by the microcontroller after receiving an equalization instruction of the upper computer, the equalization instruction of the upper computer is obtained when an output result of the upper computer is 1 after receiving a voltage monitoring result, and the output result of 1 indicates that the target battery cell is in a floating state and the voltage of the target battery cell is greater than a preset threshold value.

[0011] The discharge unit comprises a transistor, a sampling resistor, a fuse and a discharge power resistor, wherein:

[0012] The control end of the transistor is electrically connected with the microcontroller, and the input end of the transistor is electrically connected with the target battery cell;

[0013] The first end of the sampling resistor is electrically connected with the output end of the transistor, and the second end of the sampling resistor is grounded;

[0014] The transistor is turned on by receiving the control signal and discharges by using the sampling resistor;

[0015] The first end of the fuse is electrically connected with the target battery cell, and the second end of the fuse is electrically connected with the first end of the transistor;

[0016] The first end of the discharge power resistor is electrically connected with the second end of the fuse, and the second end of the discharge power resistor is electrically connected with the first end of the transistor;

[0017] The number of the battery monitoring units is the same as the number of the battery cells in the energy storage system, and each battery monitoring unit monitors one battery cell in the energy storage system;

[0018] The microcontroller is electrically connected with the first end of the sampling resistor and samples during the discharging process.

[0019] Optionally, the resistance value of the sampling resistor ranges from 0.2 ohm to 3 ohm, and the peak discharge current of the sampling resistor ranges from 4A to 6A.

[0020] Optionally, the transistor comprises a bipolar transistor, a junction field effect transistor and an insulated gate field effect transistor.

[0021] Optionally, the transistor further comprises an N-type transistor or a P-type transistor, wherein the control signal of the N-type transistor is a low-level signal, and the control signal of the P-type transistor is a high-level signal.

[0022] Optionally, the fuse comprises a glass tube fuse, a ceramic tube fuse and a plastic package fuse.

[0023] Optionally, the resistance value of the discharge power resistor ranges from 15 ohm to 30 ohm.

[0024] Compared with the prior art, the control system of the energy storage system has at least the following beneficial effects:

[0025] The voltage of each battery cell is monitored by the battery monitoring unit, precise measurement of the voltage of each battery cell is realized, performance degradation or safety hazards caused by uneven battery cell voltage are avoided, the host computer can realize real-time sampling, and the voltage of the battery cell is ensured to be within a reasonable range. Further, when the target battery cell is in a floating state and the voltage exceeds the preset threshold, the host computer can issue an equalization instruction to the microcontroller, so that the microcontroller can receive the equalization instruction issued by the host computer and send a control signal to the discharging unit, and the voltage of the target battery cell is reduced through the discharging unit to prevent overcharging from damaging the battery cell, thereby prolonging the service life of the battery cell. In addition, the discharging unit is composed of a transistor, a sampling resistor, a fuse and a discharging power resistor, which provides multiple protections for the target battery cell: the fuse can prevent the target battery cell from accidentally short-circuiting or overcurrent damage to the discharging unit; the sampling resistor and the discharging power resistor are used to accurately control and monitor the discharging power, and improve the accuracy and safety of the discharging process. Therefore, the control system of the energy storage unit can improve the reliability, efficiency and safety of the target battery cell, and prolong the service life of the target battery cell.

[0026] Of course, any product implementing the present application does not necessarily need to achieve all the above technical effects at the same time.

[0027] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the application.

[0029] Figure 1 is a circuit schematic diagram of the control system of the energy storage system provided by the present application. DETAILED DESCRIPTION

[0030] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. Note that the relative arrangement, numerical expressions and values of the components and steps set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0031] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting to the scope of the present application and its applications or uses.

[0032] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art(s) can not be discussed in detail herein. However, where appropriate, the techniques, methods, and apparatus should be considered as being illustrative only and should not be considered as limiting.

[0033] In all of the examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not limiting. Thus, other examples of the illustrative embodiments can have different values.

[0034] It should be noted that like reference numerals and letters refer to like items throughout the drawings, and once an item is defined in one drawing, it should not require further discussion in subsequent drawings.

[0035] Embodiment 1

[0036] Referring to Figure 1 , Figure 1 is a circuit schematic diagram of the control system of the energy storage system provided by the utility model.

[0037] As Figure 1 shown, the control system of the energy storage system provided by the utility model includes a host computer M1 and at least one battery monitoring unit 100 (for example, it can also include but is not limited to a battery detection unit 200, a battery detection unit 300, etc.), wherein: the battery monitoring unit 100 is in communication connection with the host computer M1, and the voltage of at least one battery cell (not shown in the figure) is monitored.

[0038] It should be noted that the host computer M1 is the main control unit of the control system, and is used for coordinating and managing the battery monitoring unit 100 in the energy storage system. Specifically, the host computer M1 can be connected with the battery monitoring unit 100 through a communication protocol, so as to realize the operations of reading data, issuing commands, etc. Among them, the utility model does not limit the above-mentioned communication protocol, for example, it can include Modbus protocol, CAN protocol, RS485 protocol or other bus protocol, so as to ensure the stability and real-time performance of the communication between the host computer M1 and the battery monitoring unit 100.

[0039] For example, the battery monitoring unit 100 is used for monitoring the first battery cell; the battery monitoring unit 200 is used for detecting the second battery cell; and the battery monitoring unit 300 is used for monitoring the third battery cell. Thus, the host computer M1 can be connected with the battery monitoring unit 100, the battery monitoring unit 200 and the battery monitoring unit 300 respectively, so as to realize the monitoring of the voltage of each battery cell.

[0040] The battery monitoring unit 100 comprises a microcontroller U2 and a discharging unit 101, wherein: the host computer M1 is in communication connection with the microcontroller U2, and sends the voltage of a target battery cell (not shown in the figure) to be monitored to the microcontroller U2, the target battery cell being the currently monitored battery cell, and the microcontroller U2 can return the voltage monitoring result of the target battery cell to the host computer M1; the discharging unit 101 is in electrical connection with the host computer M1 and the target battery cell, and the discharging unit 101 can receive the control signal of the microcontroller U2 to discharge the target battery cell; wherein the control signal is issued by the microcontroller U2 after receiving the equalization instruction of the host computer M1, and the equalization instruction of the host computer M1 is obtained by the host computer M1 when the output result is 1 after receiving the voltage monitoring result, and the output result of 1 indicates that the target battery cell is in a floating state and the voltage of the target battery cell is greater than a preset threshold.

[0041] For example, the microcontroller U2 is used to receive the equalization instruction of the host computer M1 and control the work of the discharging unit 101. Specifically, the microcontroller U2 can receive the monitoring request signal from the host computer M1 to monitor the voltage of the target battery cell, thereby obtaining the voltage monitoring result and returning it to the host computer M1. Further, the microcontroller U2 can issue a control signal to the discharging unit 101 according to the equalization instruction of the host computer M1, so that the discharging unit 101 can discharge the target battery cell. Wherein the microcontroller U2 and the host computer M1 can be in communication connection through a communication protocol (such as Modbus protocol, CAN protocol or RS485 protocol, etc.), which is not limited by the utility model.

[0042] For example, the discharging unit 101 can discharge the target battery cell, thereby reducing the voltage of the target battery cell and ensuring that it is within a safe range. Specifically, the discharging unit 101 is in electrical connection with the target battery cell and the microcontroller U2, respectively, for receiving the control signal from the microcontroller U2 and starting the discharging operation.

[0043] For example, the host computer M1 can receive the voltage monitoring result of the microcontroller U2, thereby monitoring the voltage of the target battery cell in real time and obtaining its voltage state. If the voltage of the target battery cell is greater than the preset threshold, and the voltage of the target battery cell is in a floating state, the host computer M1 can output the result as 1 and send the equalization instruction to the microcontroller U2. Wherein the utility model does not limit the preset threshold, for example, when the target battery cell is 12V, the preset threshold can include 13V; or, when the target battery cell is 2V, the preset threshold can include 2.1V.

[0044] It should be noted that the floating state is a common state in the charging of the battery, and mainly appears in the low current and low voltage charging stage applied after the battery is fully charged in order to maintain the full state thereof. Specifically, in order to avoid the battery from being caused to drop in power due to self-discharge during long-term standby, after the battery is fully charged, the floating state can be maintained so that the self-charging current thereof is gradually reduced to a very low level, only compensating for the energy loss of the self-discharge of the battery, thereby prolonging the service life of the battery itself.

[0045] If the target battery is in the floating state and the voltage is too large (i.e., exceeds the preset threshold), it indicates that the voltage of the target battery exceeds the safe range after being fully charged due to the floating voltage being set too high or being improperly controlled, which seriously affects the performance and service life of the battery, and even brings safety hazards. Therefore, the host computer M1 can monitor the voltage state of the target battery in real time, and output a result of 1 when the voltage state of the target battery is that the voltage of the target battery is greater than the preset threshold and the target battery is in the floating state, and send an equalization instruction to the microcontroller U2, so as to avoid the voltage of the target battery being too large and affecting the service life thereof.

[0046] The discharging unit 101 comprises a transistor U1, a sampling resistor R2, a fuse F1 and a discharging power resistor R1, wherein: the control end of the transistor U1 is electrically connected to the microcontroller U2, and the input end of the transistor U1 is electrically connected to the target battery; the first end of the sampling resistor R2 is electrically connected to the output end of the transistor U1, and the second end of the sampling resistor R2 is grounded; the transistor U1 is turned on by receiving a control signal and discharges by using the discharging power resistor R1; the first end of the fuse F1 is electrically connected to the target battery, and the second end of the fuse F1 is electrically connected to the first end of the transistor U1; the first end of the discharging power resistor R1 is electrically connected to the second end of the fuse F1, and the second end of the discharging power resistor R1 is electrically connected to the first end of the transistor U1.

[0047] For example, the transistor U1 can comprise an N-channel MOSFET or a bipolar transistor, etc., which is not limited in the present application, and the transistor U1 serves as a switching element and can be turned on or off according to the control signal sent by the microcontroller U2; the sampling resistor R2 can monitor the discharging current, so as to be used for monitoring the change of the current during the discharging of the target battery; the fuse F1 can protect the circuit and prevent the transistor U1 or other elements in the circuit from being damaged due to excessive current; and the discharging power resistor R1 can be used for limiting and consuming the electric energy discharged by the target battery, so as to prevent the current from being too large.

[0048] For example, the control system of the energy storage system provided by the utility model can include the following working principles: the host computer M1 is in communication connection with the microcontroller U2, and sends the voltage of the target battery cell subjected to monitoring to the microcontroller U2, and the microcontroller U2 returns the voltage monitoring result of the target battery cell to the host computer M1. Thus, the host computer M1 can obtain the real-time voltage information of the target battery cell through communication. Further, when the host computer M1 outputs the result as 1 after receiving the voltage monitoring result, it indicates that the voltage of the target battery cell exceeds the preset threshold value and is in the floating state. Thus, the host computer M1 can send the equalization instruction to the microcontroller U2, and then the microcontroller U2 can send the control signal to the discharging unit 101 after receiving the equalization instruction. On this basis, the control end of the transistor U1 changes from the cut-off state to the conducting state after receiving the control signal, forming a path, and the current flows from the positive electrode of the target battery cell, passes through the fuse F1, the discharging power resistor R1 and the transistor U1, and then passes through the sampling resistor R2, and finally flows to the ground. During the discharging process, the target battery cell is discharged through the discharging power resistor R1, thereby reducing the voltage of the target battery cell.

[0049] Among them, the voltage drop of the sampling resistor R2 reflects the size of the current flowing through. The microcontroller U2 can monitor the discharging current in real time by measuring the voltage across the sampling resistor R2, thereby adjusting the conducting state of the transistor U1 to ensure stable discharging. If an abnormality (such as short circuit or excessive current) occurs in the discharging circuit, the fuse F1 will melt and cut off the circuit to prevent further damage to other components.

[0050] The discharging unit 101 utilizes the switching characteristics of the transistor U1 to dissipate the excess energy of the target battery cell through the discharging power resistor R1, and simultaneously realizes accurate monitoring and protection through the sampling resistor R2 and the fuse F1, ensuring that the entire discharging process is safe, reliable and efficient.

[0051] The number of battery monitoring units 100 is the same as the number of battery cells in the energy storage system (not shown in the figure), and each battery monitoring unit 100 monitors one battery cell in the energy storage system; the microcontroller U2 is electrically connected to the first end of the sampling resistor R2 and samples during the discharging process.

[0052] For example, if the energy storage system contains 12 battery cells, 12 battery monitoring units 100 are required, and each battery monitoring unit 100 corresponds to the management of one battery cell. Thus, it can be ensured that each battery cell can be independently monitored and managed, avoiding measurement deviation or control delay due to multiple battery cells sharing one battery monitoring unit 100.

[0053] For example, the microcontroller U2 is electrically connected to the first end of the sampling resistor R2 and samples during the discharging process. In this way, the microcontroller U2 can obtain the sampling result by reading the voltage across the sampling resistor R2, and then send the sampling result to the host computer M1 to determine whether the discharging process is normal, such as whether the discharging current is too large or too small, whether the on state of the transistor U1 needs to be adjusted, whether the discharging operation can be stopped, and the like. In this way, overcharging, overdischarging and other safety problems that may be caused can be avoided, and the service life of the target battery cell is also enhanced.

[0054] Compared with the prior art, the control system of the energy storage system has at least the following beneficial effects:

[0055] The voltage of each battery cell is monitored by the battery monitoring unit 100, so that the voltage of each battery cell can be accurately measured, and the performance degradation or safety hazards caused by uneven battery cell voltage can be avoided. The host computer M1 can perform real-time sampling to ensure that the battery cell voltage is within a reasonable range. Further, when the target battery cell is in the floating charging state and the voltage exceeds the preset threshold, the host computer M1 can issue an equalization instruction to the microcontroller U2, so that the microcontroller U2 can receive the equalization instruction issued by the host computer M1 and send a control signal to the discharging unit 101, and the voltage of the battery cell is reduced by the discharging unit 101 to prevent overcharging from damaging the battery cell, thereby prolonging the service life of the battery cell. In addition, the discharging unit 101 is composed of the transistor U1, the sampling resistor R2, the fuse F1 and the discharging power resistor R1, which provides multiple protections for the target battery cell. The fuse F1 can prevent the target battery cell from being damaged by accidental short circuit or overcurrent. The sampling resistor R2 and the discharging power resistor R1 are used to accurately control and monitor the discharging power, thereby improving the accuracy and safety of the discharging process. Therefore, the control system of the energy storage unit can improve the reliability, efficiency and safety of the target battery cell, and prolong the service life of the battery cell.

[0056] Embodiment 2

[0057] On the basis of the above-mentioned embodiments, the control system of the energy storage system provided by the present application can further include the following features:

[0058] Optionally, the resistance value of the sampling resistor R2 is in the range of 0.2 ohms to 3 ohms, and the peak discharging current of the sampling resistor R2 is in the range of 4A to 6A.

[0059] It should be understood that if the resistance value of the sampling resistor R2 is too low, the voltage drop generated by the discharge current is too small, and the microcontroller U2 is difficult to accurately collect the current signal, which may cause insufficient current monitoring accuracy and affect the stability of the discharge control. If the resistance value of the sampling resistor R2 is too high, although the voltage drop is large and the signal is easy to collect, it will also cause the sampling resistor R2 to consume too much energy, which may affect the long-term stability of the sampling resistor. Therefore, the resistance value of the sampling resistor R2 is in the range of 0.2 ohms to 3 ohms, which not only ensures low power loss, but also provides sufficient voltage signals for measurement.

[0060] For example, if the peak current of the discharge current of the sampling resistor R2 is less than 4A, the discharge speed is slow, which may prolong the time of the target battery in a high-voltage state and increase the risk of battery damage. If the peak current of the discharge current of the sampling resistor R2 is higher than 6A, the discharge speed is faster, but it may cause the sampling resistor R2, the discharge power resistor R1 or the transistor U1 to overheat or even be damaged. Therefore, the peak current of the discharge current of the sampling resistor R2 is in the range of 4A to 6A, which can quickly restore the voltage of the target battery to a safe range and avoid damage or safety hazards caused by overcharging.

[0061] Optionally, the transistor U1 includes a bipolar transistor, a junction field effect transistor, and an insulated gate field effect transistor.

[0062] It should be noted that the bipolar transistor is a current-controlled semiconductor device with three main parts: emitter, base, and collector. The bipolar transistor controls the collector current through the base current, and its operation depends on the movement of electrons and holes. The working principle of the bipolar transistor is based on current, not voltage control. Further, the bipolar transistor is suitable for switching operation of large current, can withstand high current load, and the manufacturing cost of the bipolar transistor is relatively low, suitable for large-scale application.

[0063] The junction field effect transistor is a device that uses an electric field to control current, consisting of a source, a drain, and a gate. Unlike bipolar transistors, the junction field effect transistor is a voltage-controlled device. The junction field effect transistor controls the current between the source and the drain through the gate voltage. The higher the gate voltage, the smaller the current, and vice versa. The junction field effect transistor has very high input impedance and is suitable for low-power applications such as signal processing. Due to its working principle, the junction field effect transistor usually consumes less power when operating, so it is suitable for systems that require long-term operation and high energy efficiency, and the junction field effect transistor is also suitable for applications that require high input impedance.

[0064] An insulated-gate field-effect transistor controls the current between the source and the drain through the voltage of the gate. The working principle of an insulated-gate field-effect transistor is electric field control, and the gate voltage controls the conductivity of the channel. Insulated-gate field-effect transistors have high efficiency and low loss in high-current and high-frequency applications. Insulated-gate field-effect transistors can achieve very fast switching response and are suitable for applications requiring fast control. Compared with bipolar transistors, insulated-gate field-effect transistors have very low power consumption and are particularly suitable for long-running systems.

[0065] For example, the selection of the transistor U1 can be determined according to the requirements of the discharge control. Insulated-gate field-effect transistors are preferred due to their high efficiency, low power consumption, and fast switching characteristics. Bipolar transistors are suitable for high-current applications, and junction field-effect transistors are more suitable for low-power and high-impedance applications.

[0066] Optionally, the transistor U1 further includes an N-type transistor or a P-type transistor, wherein the control signal of the N-type transistor is a low-level signal, and the control signal of the P-type transistor is a high-level signal.

[0067] For example, the transistor U1 can include an N-type transistor or a P-type transistor, and the level of its control signal will be different according to the type of the transistor.

[0068] For example, the N-type transistor controls the conduction and shutdown between the source and the drain by applying a certain voltage to the gate. The working principle is that the gate voltage makes the conduction channel between the source and the drain form or break. For an N-type transistor, a low-level signal (logic "0") is used as the control signal to turn on the N-type transistor. Specifically, the channel between the source and the drain of the N-type transistor will only be conductive when the gate voltage is higher than a certain threshold of the source voltage. When the control signal is low, the gate voltage is lower than the threshold, and the N-type transistor is in the on state.

[0069] For example, the working principle of the P-type transistor is similar to that of the N-type transistor, but its conduction channel is dominated by holes (positive charge carriers). When the gate voltage is relatively low with respect to the source voltage, the P-type transistor is conductive. That is, a lower voltage needs to be applied to the gate of the P-type transistor to make it conductive. For a P-type transistor, a high-level signal (logic "1") is usually used as the control signal to turn on the transistor. Specifically, when the gate voltage is close to the source voltage (or lower than the source voltage threshold), the P-type transistor is conductive.

[0070] Optionally, the fuse F1 includes a glass tube fuse, a ceramic tube fuse, and a plastic package fuse.

[0071] It should be noted that the glass tube fuse is usually composed of a glass tube shell and a metal wire inside. The metal wire conducts electricity under normal current, but when the current exceeds a safe value, the metal wire will melt and cut off the circuit. The glass tube fuse is transparent, so that the user can directly see whether it is melted, which is convenient for inspection, and the glass tube fuse is relatively small and suitable for low current protection.

[0072] The shell of the ceramic tube fuse is made of ceramic material, and there is also a metal wire inside. The ceramic tube fuse has better high temperature resistance, impact resistance and stronger mechanical strength than the glass tube fuse, and is suitable for high current and high power circuits. The ceramic shell has good heat resistance and can withstand high working temperature; the ceramic material has strong high temperature resistance and is suitable for high temperature environment or large current circuit; the ceramic tube is relatively firm and has good impact resistance and is not easy to break, and the ceramic tube fuse is suitable for withstanding larger current, especially overload current.

[0073] The plastic package fuse adopts a plastic shell to package the internal metal wire, and the shell is usually made of durable plastic materials such as polyester and polycarbonate. The plastic package fuse is often used in small and light electrical equipment, and the plastic package fuse is relatively light and suitable for small electronic products and equipment. At the same time, the manufacturing cost of the plastic package fuse is low, and it is suitable for cost-sensitive applications.

[0074] Optionally, the resistance value of the discharging power resistor R1 is in the range of 15 ohms to 30 ohms.

[0075] It should be understood that if the resistance value of the discharging power resistor R1 is lower than 15 ohms, a larger discharging current can be provided to make the discharging speed of the target battery faster, but it can also make the heat during the discharging process higher, and thus the discharging power resistor R1 needs to withstand more heat loss. If the resistance value of the discharging power resistor R1 is higher than 30 ohms, a smaller discharging current is provided, making the discharging process of the target battery slower, and thus the voltage reduction speed is slower.

[0076] Therefore, the resistance value of the discharging power resistor R1 is in the range of 15 ohms to 30 ohms, which not only ensures that the voltage of the target battery is reduced to a safe range within a short time, but also avoids excessive heat caused by excessive current, prolonging the service life and reliability of the target battery.

[0077] Although some specific embodiments of the present application have been described in detail by examples, those skilled in the art should understand that the above examples are only for illustration, not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A control system for an energy storage system, characterized by, The control system comprises a host computer and at least one battery monitoring unit, wherein: Each battery monitoring unit is in communication connection with the host computer and monitors the voltage of at least one battery cell in the energy storage system; Each battery monitoring unit comprises a microcontroller and a discharging unit, wherein: The host computer is in communication connection with the microcontroller and sends the voltage of the target battery cell to the microcontroller, the target battery cell being the currently monitored battery cell, and the microcontroller returns the voltage monitoring result of the target battery cell to the host computer; The discharging unit is in electrical connection with the microcontroller and the target battery cell, and the discharging unit receives the control signal of the microcontroller to discharge the target battery cell; wherein the control signal is issued by the microcontroller after receiving the equalization instruction of the host computer, the equalization instruction of the host computer is obtained by the host computer when the output result is 1 after receiving the voltage monitoring result, and the output result of 1 indicates that the target battery cell is in a floating state and the voltage of the target battery cell is greater than a preset threshold; The discharging unit comprises a transistor, a sampling resistor, a fuse and a discharging power resistor, wherein: The control end of the transistor is electrically connected to the microcontroller, and the input end of the transistor is electrically connected to the target battery cell; The first end of the sampling resistor is electrically connected to the output end of the transistor, and the second end of the sampling resistor is grounded; The transistor is turned on by receiving the control signal and discharges by using the sampling resistor; The first end of the fuse is electrically connected to the target battery cell, and the second end of the fuse is electrically connected to the first end of the transistor; The first end of the discharging power resistor is electrically connected to the second end of the fuse, and the second end of the discharging power resistor is electrically connected to the first end of the transistor; The number of battery monitoring units is the same as the number of battery cells in the energy storage system, and each battery monitoring unit monitors one battery cell in the energy storage system; The microcontroller is electrically connected to the first end of the sampling resistor and samples during discharging.

2. The control system of claim 1, wherein, The resistance value of the sampling resistor ranges from 0.2 ohms to 3 ohms, and the peak discharge current of the sampling resistor ranges from 4A to 6A.

3. The control system of claim 1, wherein, The transistor comprises a bipolar transistor, a junction field effect transistor and an insulated gate field effect transistor.

4. The control system of claim 1, wherein, The transistor further comprises an N-type transistor or a P-type transistor, wherein the control signal of the N-type transistor is a low-level signal, and the control signal of the P-type transistor is a high-level signal.

5. The control system of claim 1, wherein, The fuse comprises a glass tube fuse, a ceramic tube fuse and a plastic package fuse.

6. The control system of claim 1, wherein, The resistance value of the discharging power resistor ranges from 15 ohms to 30 ohms.

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