CN106961150B - Control method and system of composite energy storage battery - Google Patents

Abstract

The invention relates to the field of electrical control, in particular to a control method and system for a composite energy storage battery. After the AC power generated by the power generation module is converted into DC power, the DC power is output from the DC bus; the inverter converts the DC power into AC power suitable for the corresponding load and then provides it to the corresponding load; When the AC power is more than the AC power required by the load, the excess AC power is converted into DC power, and the DC power is stored in the energy type battery and/or power type battery under the control of a battery controller; when the power generation module When the generated AC power is less than the AC power required by the load, the battery controller controls the energy-based battery and/or the power-based battery to provide power to the load, wherein the power-based battery has a lower power density than the power-based battery; larger than power type batteries.

Description

Control method and system for composite energy storage battery

technical field

The invention relates to the field of electrical control, in particular to a control method and system for a composite energy storage battery.

Background technique

At present, the wind-solar hybrid system is a distributed energy power supply system, which usually includes four major components: wind turbines, photovoltaic modules, wind-solar hybrid controllers, batteries (usually lead-acid batteries) and inverters, as shown in Figure 1. The wind-solar hybrid power supply system can solve the problem of electricity consumption in remote areas or areas with inconvenient power supply. For example, wind turbines convert wind energy into three-phase AC output, usually using permanent magnet generators, and small wind turbines usually do not have the function of pitching. The photovoltaic module converts solar energy into DC power output. The function of the wind-solar hybrid controller is to convert the AC power output by the permanent magnet wind turbine into DC power, match the battery voltage, and realize the protection of the wind turbine, photovoltaic reverse power protection, and battery charging protection. The maximum power tracking of wind turbines and photovoltaics can also be realized as required. The battery plays a vital role in the whole system. When the wind and solar resources are in good condition, the battery is charged to store the remaining electric energy. When the wind and wind resources are not good, the stored energy is output for the electricity load through the battery discharge. At present, colloidal lead-acid batteries are usually used for batteries.

The wind-solar hybrid power supply system puts forward higher demands on the energy density, power density, service life and price of energy storage batteries, which are difficult to meet by traditional lead-acid batteries or lithium batteries. The existing lead-acid battery has a relatively low cycle charge and discharge life, generally only 200 to 500 times. The battery of the wind-solar hybrid power supply system usually needs to be replaced in about a year; The power of the load increases gradually, especially when the short-term high-power load is used, the short-term peak power of the load increases greatly. In order to solve this problem, in addition to wind turbines and photovoltaic modules with larger power generation, it is also necessary to configure batteries with larger capacity to meet the power demand. Lead-acid batteries have high energy density, but low power density, so the number of parallel lead-acid batteries can only be increased, and the lead-acid battery is forced to increase the configuration capacity to obtain large charging and discharging power, which greatly increases the volume, weight and cost of the system. ; If considering various factors such as electricity demand, system cost, volume and weight, the battery configuration is more inclined to adopt the configuration scheme of high power and minimum energy storage capacity. The battery no longer works in the condition of low current charging and discharging, but high current charging and discharging will reduce the utilization rate of battery energy storage, and also reduce the service life of lead-acid batteries.

In the traditional wind-solar hybrid power supply system, the lead-acid battery is directly connected between the charging power source and the electricity load. The charging and discharging of the lead-acid battery depends on the difference between the wind-solar power generation power and the electricity load power. The charging and discharging of the lead-acid battery is completely uncontrolled. , There is no other means and way to realize the charge and discharge management of the battery, and it is impossible to effectively improve the battery utilization rate and service life. In addition, the wind-solar hybrid power supply system, the use of lead-acid batteries is too extensive, and the lack of control of lead-acid battery power, unbalanced conditions and The monitoring of health status is not conducive to use and maintenance. Even if there is a composite energy storage, a composite battery component is formed by connecting a lithium battery and a lead-acid battery in parallel. The matching requirements of the two batteries are extremely high, and the two batteries The output characteristics of the battery cannot be controlled independently and flexibly, and the complementary characteristics of the two batteries cannot be fully utilized. The effect of improving the lifespan and energy utilization is greatly reduced.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the prior art, the present invention provides a control method and system for a composite energy storage battery that increases the overall life of the battery.

The present invention includes the following technical solutions:

A control method of a composite energy storage battery, the control method comprising:

After converting the AC power generated by the power generation module into DC power, and outputting the DC power from the DC bus;

The inverter device converts the direct current electric energy into alternating current electric energy suitable for the corresponding load and provides it to the corresponding load; wherein,

When the AC power generated by the power generation module is more than the AC power required by the load, the excess AC power is converted into DC power, and the DC power is stored in the energy under the control of a battery controller. type batteries and/or power type batteries;

When the AC power generated by the power generation module is less than the AC power required by the load, the battery controller controls the energy type battery and/or the power type battery to provide power to the load, wherein,

The power density of the energy type battery is lower than that of the power type battery; the energy density of the energy type battery is higher than that of the power type battery.

Preferably, in the control method, the energy type battery is a lead-acid battery and/or the power type battery is a lithium battery.

Preferably, in the control method, when the AC power generated by the power generation module is less than the AC power required by the load, the power battery is charged; and

When the power type battery is charged to 70% of the battery capacity, the energy type battery starts to be charged and the power type battery is charged with a voltage limit and constant current.

Preferably, in the control method, when the energy type battery is charged to 80% of the battery power, the energy type battery is charged with a constant voltage and current limit.

Preferably, in the control method, after both the energy type battery and the power type battery are fully charged, the battery controller increases the DC bus voltage, and cooperates with the power generation controller to realize the abandonment of wind and light. Preferably, in the control method, when the AC power generated by the power generation module is less than the AC power required by the load, when the power supply is less than the rated power of the load, the power battery is preferentially used for discharging , when the remaining capacity of the power type battery is 20%, the energy type battery starts to discharge.

Preferably, in the control method, when the AC power generated by the power generation module is less than the AC power required by the load, during the discharge process of the power type battery, if the discharge current of the power type battery is greater than The power battery allows a maximum discharge current, and the power battery and the energy-type battery are simultaneously discharged according to a set ratio.

Preferably, in the control method,

The battery controller collects the DC bus electrical signal on the DC bus side, and the battery controller controls the working state of the energy type battery and/or the power type battery in real time according to the collected DC bus electrical signal;

The battery controller collects the electrical signal of the energy-type battery, and controls the working state of the power-type battery and/or the energy-type battery in real time according to the electrical signal of the energy-type battery;

The battery controller collects the electrical signal of the power battery, and controls the working state of the power battery and/or the energy battery in real time according to the electrical signal of the power battery.

Preferably, the control method further includes:

The battery controller detects and/or protects the energy type battery and the power type battery.

Preferably, the control method further includes:

The battery protection system performs battery protection for the power type battery.

A control system for a composite energy storage battery, characterized in that, when applied to a process in which a power generation unit provides electrical energy to a load, the control system includes:

Inverter device;

a power generation unit, connected to the load through the inverter device, so as to provide electrical energy to the load;

A battery pack is connected to the inverter device and the power generation unit respectively, so as to store the electric energy output by the power generation unit, and the load obtains the electric energy provided by the battery pack or the power generation unit through the inverter device to work ;

a battery controller connected to the battery pack to control charging/discharging of the battery pack;

The battery pack includes at least an energy-type battery and a power-type battery, and the power-type battery has a lower power density than the power-type battery, and the energy-type battery has a higher energy density than the power-type battery.

Preferably, the power generation unit includes:

Power generation module to generate electricity;

a power generation controller, connected to the power generation module and connected to the inverter device through a DC bus, to convert the electric energy generated by the power generation module; wherein,

The power generation module includes photovoltaic components and/or wind turbines.

Preferably, the battery controller includes:

a DC bus sampling unit, for sampling the electrical signal of the DC bus to obtain the DC bus electrical signal;

a battery sampling unit, respectively sampling the electrical signals of the power-type battery and the energy-type battery to obtain the power-type battery electrical signal and the energy-type battery electrical signal;

The main control module is respectively connected to the DC bus sampling unit and the battery sampling unit, and according to the DC bus electrical signal and/or the power battery electrical signal and/or the energy battery electrical signal, the main circuit of the energy battery is and/or the main circuit of the power battery.

Preferably, the energy type battery is a lead-acid battery and/or the power type battery is a lithium battery.

The beneficial effects of the present invention are:

The invention uses the lead-acid battery and the lithium battery as independent individuals, and realizes completely independent charge and discharge control, dynamic power adjustment and energy management of the two batteries through the battery controller. In the invention, the voltages of the two batteries are matched. The requirements are very low, and can be achieved within the range of 0 to 100%, and the two battery charging and discharging methods and charging and discharging power are completely independently controlled, which can be flexibly allocated and managed according to the current state and demand of the battery, on the premise of meeting the demand. Give full play to the individual characteristics of the two batteries, improve battery energy utilization, and improve battery life. Through charge and discharge control and energy management, under normal working conditions, lithium batteries with higher cycle life are given priority, and only in short-term high-power and The lead-acid battery is enabled under the requirement of long-term discharge, which reduces the frequency of use of the lead-acid battery and increases the overall life of the system.

Description of drawings

1 is a schematic structural diagram of a wind-solar hybrid power supply system in the prior art;

Fig. 2 is the structural schematic diagram of the control system of the composite energy storage of the present invention;

Fig. 3 is the variation curve of electric power generation and electric power consumption of the present invention;

4a-4c are comparative diagrams of the battery selection scheme of the present invention;

Fig. 5 is the control circuit diagram of the composite battery of the present invention;

Fig. 6 is the control schematic diagram of the battery controller of the present invention;

Fig. 7 is the electric energy management flow chart of the battery controller of the present invention;

Fig. 8 is the circuit connection diagram of the battery controller of the present invention;

9 is a circuit connection diagram of an IGBT-based battery controller in the present invention;

FIG. 10 is a circuit connection diagram of the MOSFET-based battery controller of the present invention.

Detailed ways

It should be noted that, in the case of no conflict, the following technical solutions and technical features can be combined with each other.

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

FIG. 2 is a schematic structural diagram of a wind-solar hybrid power supply system based on composite energy storage proposed in this embodiment. In this embodiment, wind-solar power generation is used as an example as a power generation module, but it is not limited to the above two power generation modes. The specific conditions can be based on actual conditions. Make settings. As shown in Figure 2, two energy storage elements are used in the system to work together. One energy storage element has high energy density and can be used as an energy battery; another energy storage element has high power density and can be called a power battery. It can meet the requirements of energy and power at the same time under the condition of reducing the volume, weight and cost as much as possible. The first energy storage element can use lead-acid batteries, which have high energy density and low cost, but low power density. The second energy storage element usually uses lithium batteries, such as lithium titanate batteries, lithium iron phosphate batteries, etc., with high power density and high energy density, but the current cost is high, the second energy storage element can also use super capacitors, super capacitors The power density is high, but the energy density is low and the cost is high. According to the user's local wind and load conditions, the ratio of the two energy storage elements is reasonably configured to achieve the best configuration of the system. Under normal circumstances, the energy storage capacity ratio of lithium battery and lead-acid battery can be 2:8, or even lower, and the specific ratio can be set according to the details.

In the prior art, wind turbines and photovoltaic modules pass through a wind-solar hybrid controller. In this embodiment, wind and photovoltaic power generation is used as an example. If other forms of power generation are used, the corresponding power generation controller can be used, that is, wind-solar hybrid power generation. The controller can be used as a kind of power generation controller. In this embodiment, the AC power generated by the wind and photovoltaic power generation modules is converted into DC power and output to the inverter through the DC bus. The AC power used by the electrical load (load) phase is output to the load. As shown above, the two types of batteries mentioned above can be connected to the DC bus. When the power required by the load is less than the power generated by the power generation module, the two types of batteries can store energy according to the set mode. On the contrary, When the electrical energy required by the load is greater than the electrical energy generated by the power generation module, the two batteries will provide electrical energy for the load. In addition to the use of composite energy storage, the difference from the wind-solar hybrid power supply system in the prior art is that the energy storage element passes through a composite battery controller. Hanging on the DC bus, the composite battery controller (battery controller) is the core device for realizing the energy management of the wind-solar hybrid power supply system. Its main functions include: power distribution of lead-acid batteries and lithium batteries; charging of lead-acid batteries and lithium batteries Discharge control and battery protection; monitoring of lead-acid battery and lithium battery power, imbalance status and health status, etc.; cooperating with wind-solar hybrid controller to achieve abandonment of wind and solar energy; through the power distribution strategy of the composite battery controller to ensure the priority use of lithium battery charging Discharge, maintain the dynamic balance of system power, reduce the number of cycle charging and discharging of lead-acid batteries, and improve the service life of lead-acid batteries. The control method of the battery controller will be described in detail later.

Figure 3 is a typical graph of wind-solar power generation power and electricity load power in a day in a certain area. It can be seen that the batteries in the wind-solar hybrid power supply system need to be charged and discharged frequently within a day to achieve a dynamic balance of system power. The cycle charge and discharge life of lithium batteries is 2000 to 3000 times, and the cycle charge and discharge life of lead-acid batteries is only 200 to 500 times. As shown in Figure 4a, this embodiment is based on the power distribution strategy of composite energy storage. Discharge ensures the dynamic power balance of the system, and the lead-acid battery is only used when the power of the lithium battery is not enough during the period of poor wind conditions or peak load power consumption, which greatly improves the service life of the lead-acid battery. If the power distribution strategy of the composite battery controller is used to ensure that the high-power load is running, the higher rate discharge of the lithium battery is given priority, and the lead-acid battery is discharged at a small rate, and the best performance of the system user requirements, cost, volume and weight can be obtained. The charge-discharge rate of lead-acid batteries does not exceed 0.3C. The configuration scheme is designed according to 0.3C as shown in Figure 4b. The price of lead-acid batteries in the market is generally 500-700 yuan/kWh, and the price of lithium batteries is generally 1500-3000 yuan/kWh. kWh, which includes the price of the battery management system (BMS), so the cost of power supply can be greatly reduced through the technical solution of this embodiment.

As shown in Figure 4c, through the comparison of the above schemes, the power distribution strategy of the composite battery controller ensures that high-power load operation is given priority to the use of lithium batteries for higher rate discharge, and lead-acid batteries for low rate discharge. In terms of cost, volume and weight have obvious advantages. If only the cost, volume and weight are pursued, and the single energy storage method of lead-acid battery is selected, the maximum charging current of lead-acid battery will be above 0.5C, and the maximum discharge current will be above 1C. Lead-acid battery energy utilization and service life.

In this embodiment, the two batteries are connected to the DC bus through the composite battery controller, and the charge and discharge control of the two batteries can be realized by the composite battery controller. When the wind power is greater than the load power, the lithium battery is preferentially used for charging, and there is no restriction on the charging current. The remaining power (SOC) of the lithium battery reaches about 70%, and the lead-acid battery is charged. At the same time, the lithium battery is limited by constant voltage Charge to ensure that the lithium battery is fully charged. After the lithium battery is fully charged, only the lead-acid battery is charged. When the SOC of the lead-acid battery reaches about 80% and is about to be fully charged, the lead-acid battery is charged with a constant voltage and current limit. The voltage value of abandoning wind and light of the device makes the whole power supply system automatically switch to the state of abandoning wind and abandoning light after the composite battery is fully charged. When the wind power is less than the load power, the lithium battery is given priority to discharge, and the lead-acid battery is used when the discharge SOC of the lithium battery reaches about 20%. Under certain circumstances, the lithium battery and the lead-acid battery are discharged according to a certain current ratio. The charge and discharge control of the lithium battery and the lead-acid battery by the composite battery controller can not only improve the utilization rate of the battery, but also prolong the service life of the battery. The composite battery controller not only realizes the monitoring of lithium batteries, but also integrates the function of the lead-acid battery BMS to monitor the SOC, imbalance and health status of the lead-acid battery, which is conducive to the maintenance of the lead-acid battery and improves the use of the lead-acid battery. life. The battery protection system (BMS) in this embodiment can perform battery protection for the lithium battery.

Figure 5 is a schematic circuit diagram of a composite battery controller. As shown in Figure 5, the circuit schematic diagram is mainly divided into a control loop and a main loop, wherein the main loop includes a lead-acid battery main circuit and a lithium battery main circuit, both of which share a control loop . In this embodiment, the control loop includes a first voltage sampling unit (voltage sampling 1), which samples the electrical signal of the DC bus, and according to the sampled DC bus electrical signal, the first main control unit (main control 1) And/or the second main control unit (main control 2) controls the working conditions of the main circuit of the lithium battery and/or the main circuit of the lead-acid battery, and the second voltage sampling unit samples the electrical signals from the lithium battery and the lead-acid battery side respectively, It is also controlled by the first main control unit and the second main control unit according to the sampled signal. In addition, the control loop also includes a pair of external interfaces to receive signals from outside the control loop to control the control loop. The external interface will be described in detail later. Figure 6 is a control circuit diagram of a composite battery. The circuit diagram in Figure 6 is mainly divided into a lithium battery control block diagram and a lead-acid battery control block diagram. The control block diagram of each battery includes the DC bus outer loop control and the battery voltage outer loop control. When the composite battery When high-power discharge is performed, the two batteries are discharged at the same time according to a certain proportion. As shown in Figure 7, after power-on, the program automatically completes the initialization and standby states in sequence. When the superior sends the power-on command, the system enters the pre-charge state. After the pre-charge is completed, it first enters the lithium battery working state, and then the The process jumps to normal working conditions according to the corresponding state adjustment. As shown in Figure 8, the composite battery controller includes a control circuit part and a main circuit part, wherein the control circuit consists of a control board, a power board, an interface board, etc., and the main circuit part includes a lithium battery and a lead-acid battery main circuit. Part; external interfaces include DC bus interface, composite battery interface and communication interface with lithium battery BMS, etc.

In this embodiment, based on the connection diagram of FIG. 5 , the interface board and the control board adopt the RS485 communication mode, and are connected through the CAN bus, and the EPO emergency stop signal can control the stop of the control loop for circuit protection. The main control unit and the second main control unit can also control the control devices (such as the following IGBT or MOSFET) in the main circuit of the lithium battery and the main circuit of the lead-acid battery through the PWM signal according to the electrical signals sampled from the DC bus side and the battery side. parameters such as duty cycle. As shown in Figure 9, from the safety point of view, the battery voltage of the household system is generally low, the rated voltage is usually 48V, and the DC bus voltage is usually relatively high, usually 110V or even higher, the battery controller needs to achieve DC boost function, and power can flow in both directions. At the same time, considering that the current ripple of the battery will affect the utilization rate and life of the battery, the bidirectional Buck-boost circuit is used to realize the interleaved parallel connection. The power device usually selected in the case of high DC bus voltage is the IGBT, in which the IGBT is turned off. And conduction can be controlled and adjusted through the control loop. The controllers of the two batteries select the number of staggered and parallel channels according to the power requirements. In Figure 9, both the lithium battery and the lead-acid battery are staggered and connected in parallel for 3 channels. Figure 10 shows the implementation scheme of the MOSFET-based PCS controller for the composite battery. The power devices different from those in Figure 9 use MOSFETs. In addition to the staggered parallel connection, the capacity is expanded by MOSFET single-tube parallel connection. This scheme is suitable for low power, system DC busbars In the case of low voltage.

As shown in Figure 9 and Figure 10, by superimposing the current ripple, the output voltage of the lithium battery and lead-acid battery tends to be stable, preventing the output voltage from fluctuating greatly, and the switching sensitivity of the MOSFET is higher than that of the IGBT. The switching frequency of the circuit can be increased, which can enhance the stability of the output voltage.

In summary, the power distribution strategy and control method of the composite battery of the present invention, the charging and discharging of the lithium battery is preferentially used to realize the dynamic power balance of the wind-solar storage complementary power supply system, the service life of the battery is improved, and the charging and discharging control and protection of the composite battery is achieved by coordinating the two. It can realize the charge control and discharge control of lithium battery and lead-acid battery, and improve the energy utilization rate and service life of the battery; the invention realizes the independent and flexible charge and discharge control and management of the two batteries through the composite battery controller, which greatly improves the battery efficiency. The requirements for matching the two batteries are reduced; the lithium battery has a high cycle charge and discharge life, and the power balance of the wind-solar hybrid power supply system is prioritized through the charge and discharge of the lithium battery, which greatly improves the service life of the lead-acid battery; through the charging management of the lithium battery/lead-acid battery , greatly improve the effective utilization rate of lithium battery and lead-acid battery energy storage, which can reduce the configuration capacity of lithium battery and lead-acid battery, thereby reducing system cost, volume and weight; through the coordinated charging control of the two batteries, to ensure When the wind and wind resources are good and the power of one battery is high, the other battery controls the DC bus voltage, and the battery performs constant voltage and current limiting control, which not only ensures the stability of the herdsmen's wind-solar hybrid power supply system, but also achieves maximum Maximize the utilization rate of lead-acid batteries; through the discharge management of lithium batteries/lead-acid batteries, it is ensured that when high-power loads work for a short time, the lithium batteries are discharged at a high rate, and the lead-acid batteries are discharged at a small rate to ensure the load power demand. Optimizing the output distribution of the two batteries not only ensures the service life of the battery, but also reduces the configuration of the battery and reduces the cost, volume and weight.

Typical examples of specific structures of specific embodiments are given through the description and drawings, and other transformations may be made based on the spirit of the present invention. Although the above-described invention provides existing preferred embodiments, these are not intended to be limiting.

Various changes and modifications will no doubt become apparent to those skilled in the art upon reading the above description. Therefore, the appended claims should be construed to cover all changes and modifications of the true intent and scope of this invention. Any and all equivalent ranges and content within the scope of the claims should still be considered to be within the intent and scope of the invention.

Claims (10)

1. A control method for a composite energy storage battery, wherein the control method comprises: After converting the electrical energy generated by the power generation module into DC electrical energy, the DC electrical energy is output from the DC bus; The inverter device converts the direct current electric energy into alternating current electric energy suitable for the corresponding load and provides it to the corresponding load; wherein, When the AC power generated by the power generation module is more than the AC power required by the load, the excess AC power is converted into DC power, and the DC power is stored in the energy under the control of a battery controller. type batteries and/or power type batteries; When the AC power generated by the power generation module is less than the AC power required by the load, the battery controller controls the energy type battery and/or the power type battery to provide power to the load, wherein, The power density of the energy type battery is smaller than that of the power type battery; the energy density of the energy type battery is greater than that of the power type battery; In the control method, The battery controller collects the DC bus electrical signal on the DC bus side, and the battery controller controls the working state of the energy type battery and/or the power type battery in real time according to the collected DC bus electrical signal; The battery controller collects the electrical signal of the energy-type battery, and controls the working state of the power-type battery and/or the energy-type battery in real time according to the electrical signal of the energy-type battery; The battery controller collects the electrical signal of the power-type battery, and controls the working state of the power-type battery and/or the energy-type battery in real time according to the electrical signal of the power-type battery; In the control method, after the energy-type battery and the power-type battery are fully charged, the battery controller increases the DC bus voltage, and cooperates with the power generation controller to realize curtailment of wind and light. 2 . The control method of a composite energy storage battery according to claim 1 , wherein, in the control method, the energy-type battery is a lead-acid battery and/or the power-type battery is a lithium battery. 3 . 3 . The control method for a composite energy storage battery according to claim 1 , wherein, in the control method, when the AC power generated by the power generation module is more than the AC power required by the load, the said power-type battery charging; and When the power type battery is charged to 70% of the battery capacity, the energy type battery starts to be charged and the power type battery is charged with a voltage limit and constant current. 4 . The control method of the composite energy storage battery according to claim 3 , wherein, in the control method, when the energy-type battery is charged to 80% of the battery power, the energy-type battery has a constant voltage limit. 5 . flow charging. 5 . The control method of the composite energy storage battery according to claim 1 , wherein, in the control method, when the AC power generated by the power generation module is less than the AC power required by the load, the control method is 5. 6 . When the power supply power is less than the rated power of the load, the power type battery is preferentially used for discharging, and when the remaining power of the power type battery is 20%, the energy type battery starts to discharge. 6 . The method for controlling a composite energy storage battery according to claim 5 , wherein, in the control method, when the alternating current electric energy generated by the power generation module is less than the alternating current electric energy required by the load, 6 . During the discharge process of the power type battery, if the discharge current of the power type battery is greater than the allowable maximum discharge current of the power type battery, the power type battery and the energy type battery are simultaneously discharged according to a set ratio. 7. The control method of the composite energy storage battery according to claim 1, wherein the control method further comprises: The battery controller detects and/or protects the energy type battery and the power type battery. 8. The control method of the composite energy storage battery according to claim 1, wherein the control method further comprises: The battery protection system performs battery protection for the power type battery. 9 . A control system for a composite energy storage battery, characterized in that the control method for a composite energy storage battery according to any one of the preceding claims 1-8 is applied to a process in which a power generation unit provides electrical energy to a load, and the said The control system includes: Inverter device; a power generation unit, connected to the load through the inverter device, so as to provide electrical energy to the load; A battery pack is connected to the inverter device and the power generation unit respectively, so as to store the electric energy output by the power generation unit, and the load obtains the electric energy provided by the battery pack or the power generation unit through the inverter device to work ; a battery controller connected to the battery pack to control charging/discharging of the battery pack; Wherein, the battery pack includes at least an energy type battery and a power type battery, and the power density of the energy type battery is lower than that of the power type battery, and the energy density of the energy type battery is higher than that of the power type battery; The power generation unit includes: Power generation module to generate electricity; a power generation controller, connected to the power generation module and connected to the inverter device through a DC bus, to convert the electric energy generated by the power generation module; wherein, The power generation module includes photovoltaic modules and/or wind turbines; The battery controller includes: a DC bus sampling unit, for sampling the electrical signal of the DC bus to obtain the DC bus electrical signal; a battery sampling unit, respectively sampling the electrical signals of the power-type battery and the energy-type battery to obtain the power-type battery electrical signal and the energy-type battery electrical signal; The main control module is respectively connected to the DC bus sampling unit and the battery sampling unit, and according to the DC bus electrical signal and/or the power battery electrical signal and/or the energy battery electrical signal, the main circuit of the energy battery is and/or the main circuit of the power battery. 10 . The control system for a composite energy storage battery according to claim 9 , wherein the energy type battery is a lead-acid battery and/or the power type battery is a lithium battery. 11 .

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