Battery pack control method in hybrid energy storage state based on illumination

Abstract

The present invention discloses a method for controlling a battery pack in a hybrid energy storage state based on illumination, including step S1, which detects the status of multiple energy storage battery packs in real time, proceeding to step S2 if the battery pack is in a standby state, step S3 if the battery pack is in a charging state, step S4 if the battery pack is in a discharging state, and step S5 if the battery pack is in a simultaneous charge-discharge state; step S2, which detects the light irradiation status in the standby state, compares the illuminance coefficient value at that time with a set threshold, and adjusts circuit parameters based on the structure; step S3, which operates in a Buck step-down mode in the charging state, step S4, which operates in a Boost step-up mode in the discharging state; step S5, which adjusts the circuit parameters based on the difference in electrical energy between output and input in the charging-discharging state; and step S6, which returns to step S1 and repeatedly controls the multiple energy storage batteries. This new energy power generation control method enables the battery pack in the hybrid energy storage state to absorb and store new energy safely, stably, quickly, and efficiently.

Description

[Technical Field]

[0001] The present invention relates to the technical field of battery pack control, and more particularly to a method for controlling a battery pack in a hybrid energy storage state based on illumination. [Background technology]

[0002] As smart grid construction plans progress, solar energy, as an ideal renewable energy source, is seeing increasingly broad application prospects. The primary approach to developing and utilizing solar energy is photovoltaic power generation, which offers advantages such as noiselessness, pollution-free operation, universally available and inexhaustible energy, no regional restrictions, unmanned operation, a short construction cycle, and a wide degree of flexibility in scale design. Photovoltaic power generation can be implemented in two ways: off-grid stand-alone power supply and grid-connected power generation. Due to the high production costs of solar cells, photovoltaic power generation has traditionally been used in remote, unpowered areas, with many off-grid users, such as small and medium-sized systems. However, in recent years, the photovoltaic power generation industry and its market have undergone significant changes, rapidly moving toward urban grid-connected power generation, new energy vehicles, and building-integrated photovoltaic power generation.

[0003] In the prior art, there are several methods for controlling energy storage battery packs based on weather changes, but these methods do not detect and adaptively adjust the individual states of the hybrid energy storage battery in real time, nor do they involve adjusting the circuit power supply according to the light irradiation conditions. Light irradiation detection generally uses a photoresistor, but the detection accuracy is low. For example, in weather with low illumination but strong ultraviolet rays, the illumination is greatly affected by shadows caused by light irradiation, and there is no circuit that does not adjust based on the power state SOC and maximum charging capacity SOP provided by the energy storage battery pack BMS at this time, so automatic adaptability is low. Summary of the Invention

[0004] For the above problems mentioned in the prior art, in order to solve the above technical problems, the present invention provides a control method for a battery pack in a hybrid energy storage state based on illuminance, the present invention is used for a hybrid energy storage battery, and the circuit parallel connection of the present invention is suitable for parallel connection of multiple types of batteries, but can also operate independently, and includes the following steps: In step S1, the states of the multiple energy storage battery packs are detected in real time, and if they are in a standby state, the process proceeds to step S2; if they are in a charging state, the process proceeds to step S3; if they are in a discharging state, the process proceeds to step S4; and if they are in a simultaneous charging-discharging state, the process proceeds to step S5; In step S2, the light illumination status is detected, i.e., the illuminance coefficient value and the set threshold value are calculated, and it is determined whether the PV photovoltaic power generation power source is working at that time, and the standby voltage of the DC side of the DC-AC inverter device PCS is adjusted; In step S3, the control unit issues a control signal PWM for the forward charge control IGBT T-ci through the IGBT controller, and dynamically adjusts and suppresses the charge power by adjusting its duty ratio; In step S4, the control unit issues a duty ratio corresponding to the control signal PWM of the discharge control IGBT Td through the IGBT controller to dynamically adjust the DC side of the DC-AC inverter device PCS; In step S5, adjusting the participation of the energy storage battery pack BAT in charging or discharging according to the magnitude of the output power Po and the input power Pi; In step S6, the process returns to step S1, and the control of the multi-energy storage battery is repeated.

[0005] Preferably, the detecting of the light illumination condition is performed by calculating an illumination coefficient value according to the color of the RGB image of the battery pack captured in real time, and then determining the illumination. The specific illumination coefficient value γ is as follows: γ=k1R+k2G+k3B

[0006] R is the R channel value of the RGB image captured by the CCD camera, G is the G channel value of the RGB image captured by the CCD camera, and B is the B channel value of the RGB image captured by the CCD camera. k1, k2, and k3 are weighting coefficients for the R channel value, G channel value, and B channel value, respectively. The larger the illumination coefficient value γ, the stronger the illumination. 2. The method for controlling a battery pack based on illuminance and battery state according to claim 1.

[0007] Preferably, the values ​​of the weighting coefficients k1, k2, and k3 for the R, G, and B channel values ​​are all 0.33 or 255.

[0008] Preferably, after step S5, when the voltage Vi at the input port of the DC power generation power supply is greater than the voltage Vo at the output port of the DC regulated power supply, if the output power Po at this time is smaller than the input power Pi, the input-output through-hole and reverse isolation diode D4 enters a critical conduction state, and electrical energy is directly supplied to the DC-AC inverter device PCS, and the remaining power of the PV photovoltaic power supply is absorbed by the energy storage battery pack BAT, but the no-load peak voltage of the PV photovoltaic power supply must be controlled within a voltage range set on the DC side of the DC-AC inverter device PCS. If the output power Po is greater than the input power Pi, the input-output through-hole and reverse isolation diode D4 are cut off due to the boost function of the discharge circuit, and the energy storage battery pack BAT participates in charging and discharging to buffer the changes in electrical energy.

[0009] Preferably, after step S5, if the power consumption of the external power grid is less than a set threshold and there is no PV photovoltaic power generation at that time, the method further includes: activating the operation of the reverse charge control IGBT T-co by the IGBT controller based on the capacity state SOC of the energy storage battery pack, so as to absorb electrical energy from the power grid through the reverse rectification circuit of the DC-AC inverter device PCS, thereby improving energy storage.

[0010] Preferably, in the above step S2, when the plurality of energy storage battery packs are in a standby state, the operations of the forward charge control IGBT T-ci, the discharge control IGBT Td and the reverse charge control IGBT T-co are stopped.

[0011] Preferably, the gates of the forward charge control IGBT T-ci, the discharge control IGBT Td and the reverse charge control IGBT T-co are connected to corresponding IGBT controllers, respectively.

[0012] Preferably, in the above step S5, if the state type of the multiple energy storage battery packs is a simultaneous charge-discharge state, that is, if the PV photovoltaic power generation power source generates power normally and the DC-AC inverter device PCS outputs power to the power grid and operates simultaneously, the control unit detects the data of the voltage Vi and current Ii at the input port of the DC power generation power source and the voltage Vo and current Io at the output port of the DC regulated power source, as well as the charge-discharge capability parameters uploaded by the battery management system BMS of the energy storage battery packs, and simultaneously adjusts the duty ratios of the control signals PWM of the forward charge control IGBT T-ci and the discharge control IGBT Td according to the output-input electrical energy difference ΔP=Po-Pi; if the output power Po is greater than the input power Pi, the energy storage battery pack BAT engages in discharging; if the output power Po is less than the input power Pi, the energy storage battery pack BAT charges; and if the output power Po is equal to the input power Pi, the energy storage battery pack BAT operates in a critical state to perform voltage clamping and dynamic energy compensation.

[0013] Preferably, in the above step S4, if the state type of the plurality of energy storage battery packs is a discharging state, the discharge control IGBT Td, the discharge energy storage inductance Ld, and the discharge freewheel diode D2 operate in a Boost voltage step-up mode. After the control unit detects changes in the voltage Vo and current Io of the output port of the DC regulated power supply, the control unit issues and dynamically adjusts a duty ratio corresponding to the control signal PWM of the discharge control IGBT Td via the IGBT controller based on the current load power demand of the DC-AC inverter device PCS and the current maximum discharge capacity SOP2 provided by the battery management system BMS of the energy storage battery pack, so as to meet the DC side energy input demand of the DC-AC inverter device PCS within the maximum power threshold range of the system.

[0014] Preferably, in the above step S3, if the state type of the plurality of energy storage battery packs is a charging state, the forward charge control IGBT T-ci, the charging energy storage inductance Lc, and the charge return diode D1 operate in Buck step-down mode, and after the control unit detects changes in the voltage Vi and current Ii of the input port of the DC power generation power supply, the control unit issues a control signal PWM for the forward charge control IGBT T-ci via the IGBT controller based on the state of charge SOC and maximum charging capacity SOP1 detected by the energy storage battery pack BMS, and adjusts the duty ratio to dynamically adjust and suppress the charging power.

[0015] Preferably, in the above step S2, if the illumination coefficient value is smaller than the set threshold value or the PV photovoltaic power supply is not working, the standby voltage on the DC side of the DC-AC inverter device PCS is equal to the voltage of the battery pack, i.e., Vout=Vbat; if the illumination coefficient value is greater than the set threshold value and the PV photovoltaic power supply is generating power normally, then the DC-AC inverter device PCS is made through via the input-output through and reverse isolation diode D4, and the standby voltage on the DC side of the PCS is equal to the voltage of the photovoltaic power supply, i.e., Vout=Vin.

[0016] Preferably, the maximum charge capacity SOP1 or / and the maximum discharge capacity SOP2 are obtained by the following method: in step S71, a plurality of energy storage battery packs are selected, and different temperatures, polarization voltages, durations, SOC, and SOH values ​​are detected; in step S72, a constant voltage discharge is performed on the plurality of energy storage battery packs, and the constant voltage UcL and the current at the discharge end time of the battery in each charge state are recorded; in step S73, a constant voltage charge is performed on the battery, and the constant voltage UcW and the current at the charge end time of the battery in each charge state are recorded; in step S74, a constant voltage charge is performed on the battery; In step S75, constant power charging is performed on the battery to determine that the maximum discharge power of the battery in different charge states can be obtained. Subsequently, the parameters of steps S71, S72, S73, S74, and S75 are input into a convolutional neural network for training to obtain a trained convolutional neural network model. The current state of the energy storage battery pack is input into the trained convolutional neural network model to obtain the maximum charge capacity SOP1 and the maximum discharge capacity SOP2.

[0017] The present invention provides a method for controlling a battery pack in a hybrid energy storage state based on illumination, and the beneficial technical effects that can be achieved are as follows:

[0018] 1. Adaptively adjust the illuminance coefficient according to the detected light illumination conditions. If the illuminance coefficient value is lower than the set threshold or the PV photovoltaic power source is not working, the illuminance coefficient value will be judged according to the color of the image, which greatly improves the judgment accuracy.

[0019] 2. Based on the state of charge SOC and maximum charging capacity SOP1 detected by the energy storage battery pack BMS, the control unit issues a control signal PWM for the forward charging control IGBT T-ci via the IGBT controller, and dynamically adjusts and suppresses the charging power by adjusting its duty ratio, allowing the battery pack to safely, stably, quickly and efficiently absorb and store new energy.

[0020] 3. The maximum charging capacity SOP1 and maximum discharging capacity SOP2 are obtained by training a convolutional neural network algorithm based on historical data, which greatly improves accuracy.

[0021] 4. According to the output-input electrical energy difference, ΔP=Po-Pi, the duty ratio of the control signal PWM of the forward charge control IGBT T-ci and the discharge control IGBT Td is simultaneously adjusted. When the output power Po is greater than the input power Pi, the energy storage battery pack BAT is involved in discharging; when the output power Po is less than the input power Pi, the energy storage battery pack BAT is involved in charging; and when the output power Po is equal to the input power Pi, the energy storage battery pack BAT operates in a critical state, thereby realizing voltage clamping and dynamic energy compensation and improving the adaptive capability of power control.

[0022] 5. The present invention is applicable to hybrid energy storage batteries. The circuit parallel connection of the present invention is suitable for multiple types of batteries to be connected in parallel to form different types of battery packs, and these different types of batteries can be separately or independently involved in system adjustment according to their different characteristics, thereby making full use of the advantages of these different batteries. [Brief explanation of the drawings]

[0023] In order to more clearly describe the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings used in the description of the embodiments or the prior art. Of course, the drawings described below are only some embodiments of the present invention, and those skilled in the art can further obtain other drawings based on these drawings without any creative work. [Figure 1] FIG. 2 is a step schematic diagram of the method for controlling a battery pack in a hybrid energy storage state based on illumination of the present invention. [Figure 2] 1 is a state diagram of forward independent charging of the input side of a DC power conversion device in a battery pack control method based on illuminance and battery state; [Figure 3]1 is a state diagram of the independent discharge of the battery pack of the DC power conversion device in the battery pack control method based on illuminance and battery state. [Figure 4] 1 is a state diagram illustrating the charging of an energy storage battery pack BAT of a DC power conversion device in a battery pack control method based on illuminance and battery state. [Figure 5] 1 is a state diagram of reverse independent charging on the output side of a DC power conversion device in a battery pack control method based on illuminance and battery state; [Figure 6] 10 is a state diagram of a direct current power converter through-state and simultaneous charging of a battery pack in a battery pack control method based on illuminance and battery state. FIG. [Figure 7] 1 is a state diagram illustrating the state in which the energy storage battery pack BAT of the DC power conversion device is involved in discharging in the battery pack control method based on illuminance and battery state. DETAILED DESCRIPTION OF THE INVENTION

[0024] The following provides a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the drawings in the embodiments of the present invention, but of course, the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the claims of the present invention.

[0025] Example 1 Compared with the conventional new energy power generation system, the embodiment of the present invention provides a method for controlling a battery pack in a hybrid energy storage state based on illumination, which, as shown in FIG. 1 , includes the following steps: In step S1, detecting the states of a plurality of energy storage battery packs in real time, and determining the state types of the plurality of energy storage battery packs, including standby state, charging state, discharging state, and simultaneous charging-discharging state; In step S2, when the plurality of energy storage battery packs are in standby state, detect the light irradiation situation. If the illumination coefficient value is less than the set threshold value, or the PV photovoltaic power supply is not working, the standby voltage of the DC side of the DC-AC inverter device PCS is equal to the voltage of the battery pack, i.e., Vout=Vbat. If the illumination coefficient value is greater than the set threshold value and the PV photovoltaic power supply is generating normally, then the DC-AC inverter device PCS is made to pass through via the input-output pass-through and reverse isolation diode D4, and the standby voltage of the DC side of the PCS is equal to the voltage of the photovoltaic power supply, i.e., Vout=Vin. In step S3, if the state type of the multiple energy storage battery packs is a charging state, as shown in Figure 2, which is a state diagram of forward independent charging on the input side of the DC power conversion device, the forward charge control IGBT T-ci, the charging energy storage inductance Lc, and the charge return diode D1 operate in Buck step-down mode. After the control unit detects the changes in the voltage Vi and current Ii of the input port of the DC power generation power supply, the control unit issues a control signal PWM of the forward charge control IGBT T-ci through the IGBT controller based on the state of charge SOC and maximum charging capacity SOP1 detected by the energy storage battery pack BMS, and adjusts its duty ratio to dynamically adjust and suppress the charging power, allowing the battery pack to safely, stably, quickly, and efficiently absorb and store new energy. In step S4, if the state type of the plurality of energy storage battery packs is a discharging state, the discharge control IGBT Td, the discharge energy storage inductance Ld, and the discharge freewheel diode D2 operate in Boost voltage step-up mode. After the control unit detects the changes in the voltage Vo and current Io of the output port of the DC regulated power supply, the control unit issues and dynamically adjusts the duty ratio corresponding to the control signal PWM of the discharge control IGBT Td through the IGBT controller based on the current load power demand of the DC-AC inverter device PCS and the current maximum discharge capacity SOP2 provided by the battery management system BMS of the energy storage battery pack, so as to meet the DC side energy input requirement of the DC-AC inverter device PCS within the maximum power threshold range of the system, where the load power demand is determined according to the load resistance and the task requirement of the load, and specifically the load power demand can be custom-set; In step S5, if the state type of the multiple energy storage battery packs is a simultaneous charge-discharge state, that is, the PV photovoltaic power generation power source generates power normally, and the DC-AC inverter device PCS outputs power to the power grid and operates simultaneously, the control unit detects the data of the voltage Vi and current Ii of the input port of the DC power generation power source and the voltage Vo and current Io of the output port of the DC regulated power source, as well as the charge-discharge capability parameters uploaded by the battery management system BMS of the energy storage battery packs, and simultaneously adjusts the duty ratios of the control signals PWM of the forward charge control IGBT T-ci and the discharge control IGBT Td according to the output-input electrical energy difference ΔP=Po-Pi; when the output power Po is greater than the input power Pi, the energy storage battery pack BAT engages in discharge; when the output power Po is less than the input power Pi, the energy storage battery pack BAT charges; when the output power Po is equal to the input power Pi, the energy storage battery pack BAT operates in a critical state to perform voltage clamping and dynamic energy compensation; In step S6, return to step S1 to complete the control of the multi-energy battery repeatedly.

[0026] In some embodiments, after step 5, if the voltage Vi at the input port of the DC power generation power supply is greater than the voltage Vo at the output port of the DC regulated power supply, and the output power Po at this time is smaller than the input power Pi, the input-output through-hole and reverse isolation diode D4 will be in a critical conduction state, and some of the electrical energy will be directly supplied to the DC-AC inverter device PCS, and the remaining power of the PV solar power generation power supply will be absorbed by the energy storage battery pack BAT, but the no-load peak voltage of the PV solar power generation power supply must be controlled within a voltage range set on the DC side of the DC-AC inverter device PCS. If the output power Po is greater than the input power Pi, the input-output through-hole and reverse isolation diode D4 will be cut off due to the boost function of the discharge circuit, and the energy storage battery pack BAT will be involved in charging and discharging to buffer the changes in electrical energy.

[0027] In some embodiments, after step 5, if the power consumption of the external power grid is less than a set threshold, the method further includes: activating the reverse charging control IGBT T-co operation by the IGBT controller according to the capacity state SOC of the energy storage battery pack and the capacity control policy, and absorbing and storing electrical energy from the power grid through the reverse rectification circuit of the DC-AC inverter device PCS, thereby achieving the purpose of improving energy storage efficiency.

[0028] In some embodiments, in step S2, if the plurality of energy storage battery packs are in standby, the forward charge control IGBT T-ci, the discharge control IGBT Td, and the reverse charge control IGBT T-co are stopped from operating.

[0029] In some embodiments, the gates of the forward charge control IGBT T-ci, the discharge control IGBT Td and the reverse charge control IGBT T-co are respectively connected to corresponding IGBT controllers.

[0030] When the energy storage battery pack is normally online, the forward charge control IGBT (insulated gate bipolar transistor) T-ci and the discharge control IGBT Td may operate independently in a time-division manner or simultaneously, but the reverse charge control IGBT T-co operates independently only when there is no input power supply at the input port Vin+ of the DC power generation power supply and independent energy storage is required, and they all operate together in a process set by the control unit. When outputting electrical energy (including the operation of an independent power grid), the control unit detects the changes in the voltage Vo and current Io of the output port of the DC regulated power supply, and then, based on the current load power demand of the DC-AC inverter device PCS and the current discharge capacity SOP provided by the battery management system BMS of the energy storage battery pack, the control unit issues and dynamically adjusts the duty ratio corresponding to the control signal PWM of the discharge control IGBT Td via the IGBT Driver (IGBT controller) to meet the DC side energy input requirement of the DC-AC inverter device PCS within the maximum allowable power range of the system. At this time, the DC power conversion device is in the independent discharge state of the battery pack, and as shown in Figure 3, the arrow in the figure indicates the direction of the current. When the new energy generation and the DC-AC inverter device PCS are operating simultaneously, the control unit detects the data of the voltage Vi and current Ii at the input port of the DC generation power supply and the voltage Vo and current Io at the output port of the DC regulated power supply, as well as the charge-discharge capability parameters uploaded by the battery management system BMS of the energy storage battery pack, and simultaneously adjusts the duty ratios of the control signals PWM of the forward charge control IGBT T-ci and the discharge control IGBT Td according to the output-input electrical energy difference. When the output power Po is greater than the input power Pi, the energy storage battery pack BAT is involved in discharging, as shown in a state diagram in FIG. 7, where the arrow in the diagram indicates the direction of current. When the output power Po is less than the input power Pi, the energy storage battery pack BAT is involved in charging, as shown in a state diagram in FIG. 4, where the arrow in the diagram indicates the direction of current. When the output power Po is equal to the input power Pi, the energy storage battery pack BAT operates in a critical state, mainly playing the roles of voltage clamping and dynamic energy compensation.When the external power grid is in a special period, such as off-peak power consumption, and there is no new energy generation and no need to output electrical energy, the IGBT controller (IGBT Driver) activates the reverse charge control IGBT T-co operation based on the capacity state of the energy storage battery pack and the capacity control policy. The reverse rectification circuit of the DC-AC inverter PCS absorbs and stores electrical energy from the power grid, achieving the goal of efficiently storing energy during off-peak hours and reducing power waste. At this time, the DC power conversion system is in a reverse independent charging state on the output side, as shown in Figure 5, where the arrow indicates the direction of current. In any operating condition, the DC-AC inverter PCS always operates online in one direction, eliminating the need for bidirectional conversion and improving the system's response capability. When the voltage Vi at the input port of the DC power generation power supply is greater than the voltage Vo at the output port of the DC regulated power supply, and the output power Po is less than the input power Pi, the input-output through-hole and reverse isolation diode D4 will enter a critical conduction state, and some of the electrical energy will be directly supplied to the DC-AC inverter device PCS, and the remaining PV new energy will be absorbed by the energy storage battery pack BAT. At this time, the DC power conversion device will enter a through-hole and simultaneous battery pack charging state, as shown in Figure 6, the arrow in the figure indicates the direction of current. When the output power Po is greater than the input power Pi, the input-output through-hole and reverse isolation diode D4 will be cut off due to the boost function of the discharge circuit, and the energy storage battery pack BAT will intervene in the charge-discharge process in a timely manner to buffer the changes in electrical energy.

[0031] In some embodiments, when the access ports Vbat+ of the energy storage battery packs of multiple DC power conversion devices are independently connected to different energy storage battery packs, the battery management system of each energy storage battery pack controls its respective energy storage battery pack to ensure the coordinated operation of the entire system, but the monitoring policy of each battery management system is slightly different depending on the type of energy storage battery pack. Table 1 is an operating status logic table of a DC power conversion device, in which "1" indicates operation, "0" indicates stop, "↑" indicates energy storage, and "↓" indicates energy release.

[0032] [Table 1]

[0033] A brief explanation of Table 1 follows:

[0034] 1. Standby state (Table 1-No. 1): All IGBTs (T-ci, Td, T-co) are stopped, and when there is insufficient external light or the PV power supply is not working, the standby voltage on the DC side of the DC-AC inverter PCS is equal to the battery pack voltage, i.e., voltage Vout = Vbat. When there is sufficient external light and the PV power supply is normal, the DC-AC inverter PCS is switched to the through state via the input-output through and reverse isolation diode D4, and the standby voltage on the DC side is equal to the PV power supply voltage, i.e., Vout = Vin. The standby state of the DC power supply converter requires that the DC-AC inverter PCS must also be in standby state; otherwise, there is a risk.

[0035] 2. Independent charging process control (Table 1-NO.2): The forward charging control IGBT T-ci, charging energy storage inductance Lc, and charging return diode D1 operate in Buck step-down mode. After the control unit detects the changes in the voltage Vi and current Ii of the input port of the DC power source, based on the state of charge SOC and maximum charging capacity SOP given by the energy storage battery pack BMS at this time, the control unit issues a control signal PWM for the forward charging control IGBT T-ci via the IGBT driver, and adjusts its duty ratio to dynamically adjust and suppress the charging power, allowing the battery pack to safely, stably, quickly, and efficiently absorb and store new energy.

[0036] 3. Control of the independent discharge (including the operation of an independent power grid) process (Table 1-NO.3): The discharge control IGBT Td, discharge energy storage inductance Ld, and discharge freewheel diode D2 operate in Boost mode. After detecting the changes in the voltage Vo and current Io of the output port of the DC regulated power supply, the control unit will dynamically adjust the duty ratio corresponding to the control signal PWM of the discharge control IGBT Td via the IGBT Driver (IGBT controller) based on the current load power demand of the DC-AC inverter device PCS and the current discharge capacity SOP provided by the battery management system BMS of the energy storage battery pack, to meet the DC side energy input demand of the DC-AC inverter device PCS within the maximum allowable power range of the system.

[0037] 4. Control of simultaneous charge-discharge process (Table 1-NO.4): When new energy such as photovoltaic (PV) is normally generated and the DC-AC inverter device PCS outputs power to the power grid and operates simultaneously, the control unit detects the voltage Vi and current Ii of the input port of the DC power generation power supply, and the voltage Vo and current Io of the output port of the DC regulated power supply, as well as the charge-discharge capability parameters uploaded by the battery management system BMS of the energy storage battery pack, and controls the forward charge control IGBT T-ci and the discharge control IGBT according to the output-input electrical energy difference ΔP=Po-Pi. The duty ratio of the control signal PWM of Td is adjusted simultaneously. When the output power Po is greater than the input power Pi, the energy storage battery pack BAT is involved in discharging. When the output power Po is less than the input power Pi, the energy storage battery pack BAT is involved in charging. When the output power Po is equal to the input power Pi, the energy storage battery pack BAT operates in a critical state, mainly playing the role of voltage clamping and dynamic energy compensation. However, to ensure the smooth and safe operation of the DC-B-DC circuit and output electrical energy, the battery pack must be connected, and the safety priority level of all management control units is in accordance with BMS>Control Unit>PCS>EMS (Energy Management System).

[0038] 5. Control of special operating conditions (Table 1-NO. 5): When the voltage Vi at the input port of the DC power generation power supply is greater than the voltage Vo at the output port of the DC regulated power supply, if the output power Po at that time is less than the input power Pi, the input-output through-hole and reverse isolation diode D4 will enter a critical conduction state, and some of the electrical energy will be directly supplied to the DC-AC inverter device PCS, and the remaining PV new energy will be absorbed by the energy storage battery pack BAT. However, the PV no-load peak voltage must be controlled within the allowable voltage range on the DC side of the DC-AC inverter device PCS, which should be fully taken into consideration when building the system. When the output power Po is greater than the input power Pi, the input-output through-hole and reverse isolation diode D4 will be cut off due to the boost function of the discharge circuit, and the energy storage battery pack BAT will intervene in the charge-discharge process in a timely manner to buffer the changes in electrical energy.

[0039] 6. When the external power grid is in a special time period such as off-peak power consumption, when there is no new energy generation and no need to output electrical energy (for example, at night, when there is no wind, or when off-peak power consumption is present), the IGBT controller (IGBT Driver) will activate the reverse charging control IGBT T-co operation (the operating situation is the same as that of independent charging process No. 2) based on the capacity state SOC and capacity control policy of the energy storage battery pack, and collect and store electrical energy from the power grid through the reverse rectification circuit of the DC-AC inverter device PCS, thereby achieving the purpose of improving energy storage efficiency.

[0040] In some embodiments, the maximum charge capacity SOP1 and the maximum discharge capacity SOP2 are obtained by the following method: in step S11, a plurality of energy storage battery packs are selected, and different temperatures, polarization voltages, durations, SOC, and SOH values ​​are detected; in step S12, a constant voltage discharge is performed on the plurality of energy storage battery packs, and the constant voltage UcL and the current at the discharge end time of the battery at each charge state are recorded; in step S13, a constant voltage charge is performed on the battery, and the constant voltage UcW and the current at the charge end time of the battery at each charge state are recorded; and in step S14, a constant voltage charge is performed on the battery. A constant power discharge is performed to determine that the maximum discharge power of the battery in different charge states can be obtained; in step S15, a constant power charge is performed on the battery to determine that the maximum discharge power of the battery in different charge states can be obtained; then, the parameters of steps S11, S12, S13, S14, and S15 are input into a convolutional neural network for training to obtain a trained convolutional neural network model; the current state of the energy storage battery pack is input into the trained convolutional neural network model to obtain the maximum charge capacity SOP1 and the maximum discharge capacity SOP2.

[0041] In some embodiments, detecting the lighting conditions involves determining the illuminance according to an illuminance coefficient value of the color of the captured image, where the specific illuminance coefficient value γ is as follows: γ=k1R+k2G+k3B

[0042] R is the R channel value of the RGB image acquired by the CCD camera, G is the G channel value of the RGB image acquired by the CCD camera, B is the B channel value of the RGB image acquired by the CCD camera, and k1, k2, and k3 represent weighting coefficients for the R channel value, G channel value, and B channel value, respectively.

[0043] In some embodiments, the weighting factors k1, k2, and k3 for the R, G, and B channel values ​​are all 0.33 or 255.

[0044] The system of the present invention can achieve the following beneficial technical effects:

[0045] 1. Based on the state of charge SOC and maximum charging capacity SOP1 detected by the energy storage battery pack BMS, the control unit issues a control signal PWM for the forward charging control IGBT T-ci through the IGBT controller, and dynamically adjusts and suppresses the charging power by adjusting its duty ratio, allowing the battery pack to safely, stably, quickly and efficiently absorb and store new energy.

[0046] 2. Adaptively adjust according to the detected light illumination conditions. If the illuminance coefficient value is lower than the set threshold or the PV photovoltaic power source is not working, the illuminance coefficient value will be judged according to the color of the image, which greatly improves the judgment accuracy.

[0047] 3. The maximum charging capacity SOP1 and maximum discharging capacity SOP2 are obtained by training a convolutional neural network algorithm based on historical data, which greatly improves accuracy.

[0048] 4. According to the output-input electrical energy difference, ΔP=Po-Pi, the duty ratio of the control signal PWM of the forward charge control IGBT T-ci and the discharge control IGBT Td is simultaneously adjusted. When the output power Po is greater than the input power Pi, the energy storage battery pack BAT is involved in discharging; when the output power Po is less than the input power Pi, the energy storage battery pack BAT is involved in charging; and when the output power Po is equal to the input power Pi, the energy storage battery pack BAT operates in a critical state, thereby realizing voltage clamping and dynamic energy compensation and improving the adaptive capability of power control.

[0049] Although the method for controlling a battery pack based on illuminance and battery status has been described in detail above, the present specification uses specific examples to explain the principles and embodiments of the present invention, and the description of the above examples is only used to help understand the core idea of ​​the present invention, and at the same time, those skilled in the art can make any changes in the specific embodiments and application scope in accordance with the idea and method of the present invention. In short, the contents of this specification should not be understood as limiting the present invention.

Claims

1. Step S1: detecting the states of a plurality of energy storage battery packs in real time, proceeding to step S2 if they are in a standby state, proceeding to step S3 if they are in a charging state, proceeding to step S4 if they are in a discharging state, and proceeding to step S5 if they are in a simultaneous charge-discharge state; Step S2: detecting the light irradiation situation, i.e., calculating the illuminance coefficient value and the magnitude of the set threshold value, determining whether the PV photovoltaic power generation power source is operating at that time, and further adjusting the standby voltage on the DC side of the DC-AC inverter device PCS; Step S3: the control unit issues a control signal PWM for the forward charge control IGBT T-ci through the IGBT controller, and dynamically adjusts and suppresses the charging power by adjusting its duty ratio; Step S4: the control unit generates a duty ratio corresponding to the control signal PWM of the discharge control IGBT T-d through the IGBT controller to dynamically adjust the DC side of the DC-AC inverter device PCS; Step S5 of adjusting the participation of the energy storage battery pack BAT in charging or discharging based on the magnitude of the output power Po and the input power Pi; and step S6, which returns to step S1 and repeatedly controls the multi-energy storage battery. A method for controlling a battery pack in a hybrid energy storage state based on illumination, comprising:

2. The light illumination condition is detected by calculating an illumination coefficient value according to the color of the RGB image of the battery pack captured in real time, and then determining the illumination. The specific illumination coefficient value γ is as follows: γ=κ 1 R+k 2 G+k 3 B R is the R channel value of the RGB image acquired by the CCD camera, G is the G channel value of the RGB image acquired by the CCD camera, B is the B channel value of the RGB image acquired by the CCD camera, and k 1 , k 2 , k 3 represent the weighting coefficients for the R channel value, G channel value, and B channel value, respectively. The larger the illumination coefficient value γ, the stronger the illumination.

2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 1.

3. Weighting coefficient k for R channel value, G channel value, and B channel value 1 , k 2 , k 3 The values ​​of are all 0.33 or 255.

3. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 2.

4. After step S5, if the voltage Vi of the input port of the DC power generation power supply is greater than the voltage Vo of the output port of the DC regulated power supply, and the output power Po at this time is smaller than the input power Pi, the input-output through-hole and reverse isolation diode D4 enter a critical conduction state, and electrical energy is directly supplied to the DC-AC inverter device PCS, and the remaining power amount of the PV solar power generation power supply is absorbed by the energy storage battery pack BAT, but the no-load peak voltage of the PV solar power generation power supply must be controlled within a voltage range set on the DC side of the DC-AC inverter device PCS. When the output power Po is greater than the input power Pi, the input-output through-hole and reverse isolation diode D4 are cut off due to the boosting action of the discharge circuit, and the energy storage battery pack BAT participates in charging and discharging to buffer the change in electrical energy.

2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 1.

5. After step S5, if the power consumption of the external power grid is less than the set threshold and there is no PV photovoltaic power generation at that time, the IGBT controller activates the operation of the reverse charge control IGBT T-co according to the capacity state SOC of the energy storage battery pack, and absorbs electric energy from the power grid through the reverse rectification circuit of the DC-AC inverter device PCS to improve energy storage.

2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 1.

6. In step S2, if the plurality of energy storage battery packs are in a standby state, the operations of the forward charge control IGBT T-ci, the discharge control IGBT T-d, and the reverse charge control IGBT T-co are stopped.

2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 1.

7. The gates of the forward charge control IGBT T-ci, the discharge control IGBT T-d, and the reverse charge control IGBT T-co are connected to the corresponding IGBT controllers.

7. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 6.

8. In step S5, if the state type of the multiple energy storage battery packs is a simultaneous charge-discharge state, that is, if the PV photovoltaic power generation power source generates power normally and the DC-AC inverter device PCS outputs power to the power grid and operates simultaneously, the control unit detects the data of the voltage Vi and current Ii of the input port of the DC power generation power source and the voltage Vo and current Io of the output port of the DC regulated power source, as well as the charge-discharge capability parameters uploaded by the battery management system BMS of the energy storage battery packs, and simultaneously adjusts the duty ratios of the control signals PWM of the forward charge control IGBT T-ci and the discharge control IGBT T-d according to the output-input electrical energy difference ΔP=Po-Pi. If the output power Po is greater than the input power Pi, the energy storage battery pack BAT engages in discharging. If the output power Po is less than the input power Pi, the energy storage battery pack BAT charges. If the output power Po is equal to the input power Pi, the energy storage battery pack BAT operates in a critical state to perform voltage clamping and dynamic energy compensation.

2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 1.

9. In step S4, if the state type of the plurality of energy storage battery packs is a discharging state, the discharge control IGBT T-d, the discharge energy storage inductance Ld, and the discharge freewheel diode D2 operate in a Boost voltage step-up mode. After the control unit detects changes in the voltage Vo and current Io of the output port of the DC regulated power supply, the control unit issues and dynamically adjusts a duty ratio corresponding to the control signal PWM of the discharge control IGBT T-d via the IGBT controller based on the current load power demand of the DC-AC inverter device PCS and the current maximum discharge capacity SOP2 provided by the battery management system BMS of the energy storage battery pack, so as to meet the DC side energy input demand of the DC-AC inverter device PCS within the maximum power threshold range of the system.

2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 1.

10. In step S3, if the state type of the plurality of energy storage battery packs is a charging state, the forward charge control IGBT T-ci, the charge energy storage inductance Lc, and the charge return diode D1 operate in a buck step-down mode, and after the control unit detects changes in the voltage Vi and current Ii of the input port of the DC power generation power source, the control unit issues a control signal PWM for the forward charge control IGBT T-ci via the IGBT controller based on the state of charge SOC and maximum charging capacity SOP1 detected by the energy storage battery pack BMS, and adjusts the duty ratio to dynamically adjust and suppress the charging power.

2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 1.

11. In step S2, if the illumination coefficient value is smaller than the set threshold value or the PV photovoltaic power supply is not operating, the standby voltage on the DC side of the DC-AC inverter device PCS is equal to the voltage of the battery pack, i.e., Vout=Vbat. If the illumination coefficient value is greater than the set threshold value and the PV photovoltaic power supply is generating power normally, then the DC-AC inverter device PCS is made through via the input-output through and reverse isolation diode D4, and the standby voltage on the DC side of the PCS is equal to the voltage of the photovoltaic power supply, i.e., Vout=Vin.

2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 1.

12. The maximum charging capacity SOP1 or / and the maximum discharging capacity SOP2 are obtained by the following method: in step S71, a plurality of energy storage battery packs are selected, and different temperatures, polarization voltages, durations, SOC, and SOH values ​​are detected; in step S72, constant voltage discharge is performed on the plurality of energy storage battery packs, and the constant voltage UcL and the current at the discharge end time of the battery in each charge state are recorded; in step S73, constant voltage charging is performed on the battery, and the constant voltage UcW and the current at the charge end time of the battery in each charge state are recorded; and in step S74, constant power discharge is performed on the battery. In step S75, constant power charging is performed on the battery to determine that the maximum discharge power of the battery in different charge states can be obtained; then, the parameters of steps S71, S72, S73, S74, and S75 are input into a convolutional neural network for training, to obtain a trained convolutional neural network model; and the current state of the energy storage battery pack is input into the trained convolutional neural network model to obtain the maximum charge capacity SOP1 and the maximum discharge capacity SOP2. The method for controlling a battery pack in a hybrid energy storage state based on illumination as claimed in claim 10.

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