A photovoltaic and generator coordinated control charging method, system and device

Abstract

The application discloses a photovoltaic and generator coordinated control charging method, system and equipment. The method realizes the coordinated control of the photovoltaic module and the generator according to the relationship between the battery state of charge (SOC) and the set value. When the battery SOC is higher than the set value, the generator stops working, and only the photovoltaic module charges. The charging current value Ipvs is calculated through a photovoltaic charging algorithm module, and is input into a photovoltaic state machine function, so as to control the photovoltaic module to output corresponding current and complete the charging of the battery. When the battery SOC is lower than the set value, the generator and the photovoltaic module cooperatively charge. With the help of a coordinated charging algorithm module, the solar charging set value Ipvs and the generator charging set value Ibsgs are respectively calculated and output, and are respectively transmitted to corresponding solar charging state machine functions and generator state machine functions. Meanwhile, the self-adaptive switching of single generator and double generators can be realized when the generator charges, and the photovoltaic and generator cooperative charging is realized.

Description

Technical Field

[0001] This invention belongs to the field of power generation technology, and in particular relates to a method, system and equipment for coordinated control of photovoltaic and generator charging. Background Technology

[0002] Solar energy, as a clean and renewable energy source, is widely used in the automotive and shipbuilding sectors. Solar panels installed on the roofs or decks of vehicles and ships convert photovoltaic energy into lithium battery charging, which can reduce dependence on traditional energy sources. However, it has significant instability: affected by weather, sunlight angle, day and night cycles, the output voltage and current fluctuate wildly. Directly inputting such fluctuating electrical energy into lithium batteries can easily cause charging parameters to exceed safety thresholds.

[0003] Vehicle (boat) generators are another important source of charging, driven by the engine, converting mechanical energy into electrical energy to recharge lithium batteries during driving or idling. However, load fluctuations in vehicles and boats can lead to unstable output: the output voltage may drop momentarily when the power system load increases sharply, and may rise sharply when the load decreases sharply. In addition, some systems use simple parallel charging between the two, lacking an effective energy distribution mechanism, which can easily cause overcurrent or overvoltage when the outputs are superimposed.

[0004] Lithium-ion battery charging has strict requirements on voltage and current. Overvoltage can lead to electrolyte decomposition and lithium deposition, causing capacity decay and even safety hazards; overcurrent can cause a sudden rise in battery temperature, accelerating electrode aging. Although existing systems are equipped with basic protection devices such as fuses and voltage regulators, they are mostly passive protections, only cutting off the circuit after an anomaly, and cannot actively coordinate and control: when solar output increases suddenly, the voltage regulator may not respond in time and could damage the battery; when the load fluctuates, the protection devices may frequently trip, interrupting charging and reducing energy utilization efficiency. At the same time, the energy utilization efficiency of existing technologies is insufficient: when solar output is low, the system does not increase the charging power of the vehicle (boat) generator in time to make up for the shortfall; the surplus energy of the vehicle (boat) at idle is wasted due to the lack of a coordination mechanism. Therefore, achieving dynamic coordinated charging of both, while avoiding overvoltage and overcurrent and maximizing the utilization of clean energy and surplus energy, has become a technical challenge that vehicle and ship energy storage systems urgently need to solve. Summary of the Invention

[0005] This invention aims to overcome the aforementioned limitations through innovative improvements based on scenario-specific control of battery SOC. It proposes a method, system, and device for coordinated control of photovoltaic (PV) and generator charging. By precisely controlling the charging current according to different scenarios, it prevents charging parameters from exceeding battery safety thresholds from the outset. Simultaneously, based on an energy allocation strategy according to battery SOC, it achieves coordinated charging of PV and generator. This not only prevents PV energy from being idle due to insufficient output but also recovers excess energy from vehicle (ship) idling through the generator, filling potential energy gaps in PV power. Overall, this improves energy utilization and indirectly extends the driving range of vehicle and ship energy storage systems.

[0006] Specifically, the photovoltaic and generator coordinated control charging method of the present invention includes:

[0007] When the battery SOC is higher than the set value, the generator stops charging and the photovoltaic module starts charging. At this time, the photovoltaic charging algorithm module calculates the charging current value Ipvs that needs to be output to the photovoltaic state machine function. Based on the charging current value Ipvs, the photovoltaic module is controlled to output the corresponding current to the battery to complete the charging.

[0008] When the battery SOC is lower than the set value, the generator and photovoltaic module work together to charge. At this time, the coordinated charging algorithm module calculates and outputs the solar charging set value Ipvs and the generator charging set value Ibsgs to the corresponding solar charging state machine function and generator state machine function.

[0009] During generator charging, the generator automatically switches between single and dual generator charging modes.

[0010] This invention achieves precise coordinated charging of photovoltaic and generator based on battery SOC state in different scenarios. When the battery SOC is higher than the set value, the photovoltaic charging algorithm module controls the current to charge the photovoltaic system alone. When the battery SOC is lower than the set value, the coordinated charging algorithm module controls the current to charge both the photovoltaic system and the generator together. The generator can also switch between single and dual operation adaptively. This not only avoids the risk of overvoltage and overcurrent from the source to protect the life of the lithium battery, but also maximizes the utilization of solar energy and vehicle (ship) idling energy. At the same time, it adapts to vehicle and ship load fluctuations to improve the stability of the charging system and energy utilization efficiency.

[0011] Preferably, the step of calculating the charging current value Ipvs to be output to the photovoltaic state machine function through the photovoltaic charging algorithm module specifically includes:

[0012] The required charging current Ix of the battery is calculated using the PI algorithm. The calculation formula is Ix = (Io + Ibatt - N) × Kt × Kl.

[0013] The required charging current Ix of the battery is determined: if Ix < 1A, it is determined that no charging is needed; if Ix ≥ 1A, the initial charging current value Ipvs = 1A is set and output to the PV solar charger, so that the PV solar charger charges with a starting current of 1A. The initial charging current value is dynamically adjusted based on the battery SOC.

[0014] Within 100ms after charging starts, calculate the current difference Ie = It - Ipv.

[0015] The new charging current value Ipvs is calculated based on the current difference Ie. The calculation formula is: Ipvs=ΔIpv+Ie×P, and ΔIpv=Ipv+Ie×K; where the output current of the PV solar charger is stabilized by adjusting the parameters P and K.

[0016] The latest charging current value Ipvs is output to the photovoltaic state machine function to control the photovoltaic module to output the corresponding current to the battery.

[0017] Establish an N-value self-learning model: After each charging cycle, record the average charging efficiency ŋ during the charging process, where ŋ = actual battery charge / total photovoltaic output. If ŋ < 85%, then for the next charge, N = N - 0.2, reducing the compensation value to increase the actual charging current; if ŋ ≥ 90%, then for the next charge, N = N + 0.1, increasing the compensation value to avoid overcharging; the value of N is limited to 0.5 ≤ N ≤ 3 to ensure that the compensation amount is within a reasonable range.

[0018] In the formula, Io represents the maximum allowable charging current of the battery; Ibat represents the current current of the battery, with a positive value indicating that the battery is discharging externally and a negative value indicating that the battery is absorbing external current; N is a compensation parameter; It is the currently required charging current; and Ipv is the current output current of the PV solar panels. Within 100ms after charging starts, It and Ipv are collected every preset time interval to calculate the average current difference. At the same time, the standard deviation of the current difference is calculated. If the standard deviation of the current difference is >0.5A, it is determined that there is abnormal fluctuation. The median value is used instead of the average current difference value Ie to reduce the impact of instantaneous interference.

[0019] Establish a correlation model between P, K, and Ie: When Ie ≥ 2A (large current deviation): P = 0.8, K = 0.3 (increase the proportional coefficient to speed up the adjustment); when 0.5A ≤ Ie < 2A (medium current deviation): P = 0.5, K = 0.5 (balance adjustment speed and stability); when Ie < 0.5A (small current deviation): P = 0.2, K = 0.8 (increase the integral coefficient to reduce steady-state error); update the P and K values ​​every 200ms based on the latest Ie to achieve dynamic adaptation.

[0020] After each charge, key parameters such as Kt, Kl, N, P, and K, as well as the charging efficiency, are automatically archived, and a parameter-efficiency correlation database is established. When the database has recorded 100 charges, a neural network algorithm is used to optimize the initial values ​​of the parameters so that the initial parameters of subsequent charges are more in line with the actual use scenario.

[0021] Preferably, the coordinated charging algorithm module calculates, specifically including:

[0022] The direction of the battery bus current Ibat determines whether the battery is in a discharging or charging state.

[0023] The formula for calculating the required charging current Ibsgs for the generator is:

[0024] When the battery is in a discharging state, Ibsgs = (Io + Ibat - N) × Kp;

[0025] When the battery is charging, Ibsgs = (Io - Ibat - N) × Kp;

[0026] Based on the photovoltaic priority principle, the solar charging setting value Ipvs is set to a constant according to the maximum output capacity of the photovoltaic module, the current light intensity, or the battery charging demand.

[0027] Where Ipv is the photovoltaic charging current and the battery bus current; Kp is the generator priority coefficient, with a value of 0.6-1.0 that is dynamically adjustable.

[0028] Preferably, the generator charging process involves automatic switching between single and dual generator charging, specifically including:

[0029] If the required charging current Ibsgs of the generator is less than 40A, only one main generator is activated, and the current is distributed to it. The output current of the main generator is adjusted as follows: initially set to 1 / 4 Ibsgs, then increased by 0.5A-2A every 0.5s-2s, causing the output current to rise slowly from low to high. If the required charging current Ibsgs of the generator is greater than or equal to 40A, both generators are activated simultaneously, and the current is shared equally between them. The output current of each generator is adjusted as follows: initially set to 1 / 8 Ibsgs, then increased by 0.5A-2A every 0.5s-2s, causing the output current to rise slowly from low to high. When switching generator operating states, the cumulative operating time of the generator is considered. If the cumulative operating time exceeds 2 hours and the switching threshold is close, the current operating state is maintained first.

[0030] Preferably, the generator charging process automatically switches between single and dual generators during charging, further comprising:

[0031] Define the basic switching threshold I th0 The final switching threshold I is calculated based on the battery charging stage, the generator's cumulative running time, and the current load fluctuation coefficient. th =I th0 ×K adj ;

[0032] When the charging current Ibsgs th Switch to single-player mode;

[0033] When the charging current Ibsgs is greater than or equal to I th Switch to dual-machine mode;

[0034] ​During switching, the rising interval Tstep is calculated based on the difference between the initial current and the target current, and the rising step size ΔIstep is set in a segmented increment. The rising interval Tstep and the rising step size ΔIstep are adaptively adjusted according to the rising interval Tstep and the rising step size ΔIstep.

[0035] Preferred options also include:

[0036] During battery charging, monitor changes in photovoltaic charging current to determine if any sudden changes in photovoltaic data occur.

[0037] If a sudden change occurs in the photovoltaic data, the generator charging setpoint Ibsgs will be recalculated using the following formula:

[0038] Ibsgs=(Io+Id-Ipv-N)×Kd.

[0039] Kd is the mutation decay coefficient, with an initial value of 0.7, which increases by 0.05 in each adjustment period until it returns to the normal calculated value.

[0040] The adjustment cycle is set to 1 / 3 of the original cycle, the descent speed is set to 3 times the original descent amount, and a lower current limit protection is added during the descent process, with Ibsgs≥5A, to avoid the impact of restarting after the generator stops.

[0041] At the same time, the generator charging setpoint Ibsgs is controlled to decrease according to a preset adjustment cycle and decreasing speed;

[0042] The preset adjustment period is less than 1 / 2 of the generator current adjustment period before the photovoltaic data mutation; the decreasing rate is greater than twice the amount of Ibsgs decrease in each adjustment period than the amount of decrease before the photovoltaic data mutation.

[0043] Based on the same concept, the present invention also proposes a photovoltaic and generator coordinated control charging system, comprising:

[0044] The battery monitoring unit is used to monitor the current battery SOC status in real time;

[0045] The photovoltaic charging algorithm module calculates the charging current value Ipvs that needs to be output to the photovoltaic state machine function when only the photovoltaic module is charging.

[0046] The coordinated charging algorithm module calculates the solar charging setpoint Ipvs and the generator charging setpoint Ibsgs when the generator and photovoltaic module work together to charge.

[0047] The solar charging state machine function is used to control the photovoltaic module to output the corresponding current to the battery to complete charging based on the solar charging setpoint Ipvs.

[0048] The generator state machine function is used to control the generator to output the corresponding current until the battery is fully charged, based on the generator charging setpoint Ibsgs.

[0049] Preferably, the system further includes: a generator control unit;

[0050] The generator control unit adaptively switches between single and dual generators to charge the generator based on the required charging current Ibsgs and the generator's current demand time.

[0051] Preferably, the system further includes: a photovoltaic data mutation monitoring unit;

[0052] The photovoltaic data mutation monitoring unit determines whether a photovoltaic data mutation has occurred based on the change in photovoltaic charging current; if a photovoltaic data mutation occurs, it sends a command to the coordinated charging algorithm module to recalculate the generator charging setpoint Ibsgs.

[0053] Based on the same concept, the present invention also proposes a battery charging drive device, which is driven by a photovoltaic and generator coordinated control charging system as described above, so as to control the generator and PV solar charger to charge the battery.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] First, it achieves precise current control based on battery SOC in different scenarios. When SOC is high, the photovoltaic charging algorithm calculates Ipvs to control the current; when SOC is low, the coordinated algorithm calculates Ipvs and Ibsgs to control the current, thus avoiding overvoltage and overcurrent risks from the source, effectively protecting the lithium battery and extending its service life. Second, it achieves efficient energy utilization. When SOC is high, photovoltaic clean energy is used first, and when SOC is low, photovoltaic and generator charge together to maximize the capture of solar energy and recover the idling energy of the vehicle (boat), thereby improving the driving range. Third, the generator single / dual adaptive switching can dynamically adapt to the load fluctuations of the vehicle and boat, avoiding redundancy or insufficiency of power generation, ensuring the stable operation of the charging system, and improving the overall reliability. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of a photovoltaic and generator coordinated control charging method in this embodiment.

[0057] Figure 2 This is a schematic diagram of a photovoltaic and generator coordinated control charging system in this embodiment. Detailed Implementation

[0058] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0059] Example 1: As Figure 1 As shown, the photovoltaic and generator coordinated control charging method of the present invention includes:

[0060] When the battery SOC is higher than the set value, the generator stops charging and the photovoltaic module starts charging. At this time, the photovoltaic charging algorithm module calculates the charging current value Ipvs that needs to be output to the photovoltaic state machine function. Based on the charging current value Ipvs, the photovoltaic module is controlled to output the corresponding current to the battery to complete the charging.

[0061] When the battery SOC is lower than the set value, the generator and photovoltaic module work together to charge. At this time, the coordinated charging algorithm module calculates and outputs the solar charging set value Ipvs and the generator charging set value Ibsgs to the corresponding solar charging state machine function and generator state machine function.

[0062] During generator charging, the generator automatically switches between single and dual generator charging modes.

[0063] Preferably, the step of calculating the charging current value Ipvs to be output to the photovoltaic state machine function through the photovoltaic charging algorithm module specifically includes:

[0064] Preferably, the required charging current Ix of the battery is calculated using the PI algorithm. The calculation formula is Ix = (Io + Ibatt - N) × Kt × Kl, where Kt is the battery temperature compensation coefficient. The battery temperature T (unit: °C) is collected in real time by a temperature sensor and is determined according to a piecewise function: when T ≤ 15 °C, Kt = 1.2 (improving charging current compensation activity at low temperatures); when 15 °C < T < 35 °C, Kt = 1.0 (maintaining standard current at room temperature); when T ≥ 35 °C... At ℃, Kt=0.8 (reduce current to avoid thermal runaway at high temperatures); Kl is a light intensity correction term, which is collected by the light intensity L (unit: W / ㎡) by the light sensor attached to the photovoltaic module. When L<200W / ㎡, Kl=0.6 (limit charging current under weak light); when 200W / ㎡≤L<800W / ㎡, Kl=0.8 (moderately increase current under medium light); when L≥800W / ㎡, Kl=1.0 (fully utilize photovoltaic output under strong light).

[0065] The required charging current Ix of the battery is determined: if Ix < 1A, charging is deemed unnecessary; if Ix ≥ 1A, an initial charging current value Ipvs = 1A is set and output to the PV solar charger, causing the PV solar charger to charge with a starting current of 1A. The initial charging current value is dynamically adjusted based on the battery's SOC. Preferably, the current SOC value of the battery is collected in real time by the Battery Management System (BMS), divided into 5 levels according to the SOC range, and a differentiated initial charging current reference value is set for each level.

[0066]

[0067] Within 100ms after charging starts, calculate the current difference Ie = It - Ipv.

[0068] The new charging current value Ipvs is calculated based on the current difference Ie. The calculation formula is: Ipvs=ΔIpv+Ie×P, and ΔIpv=Ipv+Ie×K; where the output current of the PV solar charger is stabilized by adjusting the parameters P and K.

[0069] The latest charging current value Ipvs is output to the photovoltaic state machine function to control the photovoltaic module to output the corresponding current to the battery.

[0070] Establish an N-value self-learning model: After each charging cycle, record the average charging efficiency ŋ during the charging process, where ŋ = actual battery charge / total photovoltaic output. If ŋ < 85%, then for the next charge, N = N - 0.2, reducing the compensation value to increase the actual charging current; if ŋ ≥ 90%, then for the next charge, N = N + 0.1, increasing the compensation value to avoid overcharging; the value of N is limited to 0.5 ≤ N ≤ 3 to ensure that the compensation amount is within a reasonable range.

[0071] In the formula, Io represents the maximum allowable charging current of the battery; Ibat represents the current current of the battery, with a positive value indicating that the battery is discharging externally and a negative value indicating that the battery is absorbing external current; N is a compensation parameter; It is the currently required charging current; and Ipv is the current output current of the PV solar panels. Within 100ms after charging starts, It and Ipv are collected every preset time interval to calculate the average current difference. At the same time, the standard deviation of the current difference is calculated. If the standard deviation of the current difference is >0.5A, it is determined that there is abnormal fluctuation. The median value is used instead of the average current difference value Ie to reduce the impact of instantaneous interference.

[0072] Establish a correlation model between P, K, and Ie: When Ie ≥ 2A (large current deviation): P = 0.8, K = 0.3 (increase the proportional coefficient to speed up the adjustment); when 0.5A ≤ Ie < 2A (medium current deviation): P = 0.5, K = 0.5 (balance adjustment speed and stability); when Ie < 0.5A (small current deviation): P = 0.2, K = 0.8 (increase the integral coefficient to reduce steady-state error); update the P and K values ​​every 200ms based on the latest Ie to achieve dynamic adaptation.

[0073] After each charge, key parameters such as Kt, Kl, N, P, and K, as well as the charging efficiency, are automatically archived, and a parameter-efficiency correlation database is established. When the database has recorded 100 charges, a neural network algorithm is used to optimize the initial values ​​of the parameters so that the initial parameters of subsequent charges are more in line with the actual use scenario.

[0074] Preferably, the coordinated charging algorithm module calculates, specifically including:

[0075] The direction of the battery bus current Ibat determines whether the battery is in a discharging or charging state.

[0076] The formula for calculating the required charging current Ibsgs for the generator is:

[0077] When the battery is in a discharging state, Ibsgs = (Io + Ibat - N) × Kp;

[0078] When the battery is charging, Ibsgs = (Io - Ibat - N) × Kp;

[0079] Based on the photovoltaic priority principle, the solar charging setting value Ipvs is set to a constant according to the maximum output capacity of the photovoltaic module, the current light intensity, or the battery charging demand.

[0080] Where Ipv is the photovoltaic charging current and the battery bus current; Kp is the generator priority coefficient, with a value of 0.6-1.0 that is dynamically adjustable.

[0081] Preferably, the generator charging process involves automatic switching between single and dual generator charging, specifically including:

[0082] If the required charging current Ibsgs of the generator is less than 40A, only one main generator is activated, and the current is distributed to it. The output current of the main generator is adjusted as follows: initially set to 1 / 4 Ibsgs, then increased by 0.5A-2A every 0.5s-2s, causing the output current to rise slowly from low to high. If the required charging current Ibsgs of the generator is greater than or equal to 40A, both generators are activated simultaneously, and the current is shared equally between them. The output current of each generator is adjusted as follows: initially set to 1 / 8 Ibsgs, then increased by 0.5A-2A every 0.5s-2s, causing the output current to rise slowly from low to high. When switching generator operating states, the cumulative operating time of the generator is considered. If the cumulative operating time exceeds 2 hours and the switching threshold is close, the current operating state is maintained first.

[0083] Assuming initial operation is in single-generator mode, the main generator's current output current is 38A (corresponding to Ibsgs = 38A < 40A). At this point, due to a sudden increase in system load, the battery discharge current rises sharply, Ibat = 22A (discharge state). The generator's required current Ibsgs is recalculated: Ibsgs = 30A + 22A - 2A = 50A, satisfying the switching condition of generator required current ≥ 50A, and the duration of this required current reaches a set threshold. In this embodiment, this is set to 10 seconds to ensure non-instantaneous fluctuations, triggering the system to switch from single-generator mode to dual-generator mode. Current adjustment strategy during the switching process:

[0084] First, activate the backup generator to prevent the main generator from bearing high current alone.

[0085] The initial current values ​​for the two generators are: 1 / 8 × Ibsgs = 1 / 8 × 50A = 6.25A. The main generator first reduces the current of 38A to 6.25A at a rate of 2A per 0.5s, and the standby generator starts directly at 6.25A.

[0086] The adjustment interval is set to 1 second, and each generator increases by 1.5A each time.

[0087] After 1 second: 6.25A + 1.5A = 7.75A per unit (total 15.5A).

[0088] 2 seconds later: 7.75A + 1.5A = 9.25A per generator (total 18.5A); ... gradually increasing, eventually the two generators share 50A of current (25A per generator). After the switching is completed, the current output is stable. Throughout the process, the battery bus voltage fluctuation is controlled within ±0.3V to ensure system stability.

[0089] Preferably, the generator charging process automatically switches between single and dual generators, and the power generation control process of the dual generator system under different power states, current loads, and other operating conditions is described in detail, further including:

[0090] Define the basic switching threshold I th0 The final switching threshold I is calculated based on the battery charging stage, the generator's cumulative running time, and the current load fluctuation coefficient. th =I th0 ×K adj ;

[0091] Battery charging phase correction: Constant current charging phase K adj1 =1.0, K during constant voltage charging stage adj1 ==0.9, reduce the switching threshold near full charge to reduce the frequency of dual-machine startup;

[0092] Generator cumulative running time correction: K when the cumulative running time trun of a single generator is less than 2h adj2 ==1.0; K when 2h≤trun<4h adj2 =1.1, extending single-machine running time; K when trun≥4h adj2 ==1.2, further increasing the switching threshold to avoid single-machine overload;

[0093] Load fluctuation coefficient correction: Calculate the fluctuation coefficient Cv of the generator demand current in the first 3 seconds = current standard deviation / current average. When Cv < 5%, K adj3 =1.0; K = 5% ≤ Cv < 10% adj3 =0.95; K = when Cv≥10% adj3 =0.9, when the load fluctuates greatly, the switching threshold is reduced to improve charging stability.

[0094] Final K adj =K adj1 ×K adj2 ×K adj3 And 0.8≤K adj ≤1.2, ensuring that the threshold fluctuates within a reasonable range.

[0095] When the charging current Ibsgs th Switch to single-player mode;

[0096] When the charging current Ibsgs is greater than or equal to I th Switch to dual-machine mode;

[0097] During switching, the rise interval Tstep is calculated based on the difference between the initial current and the target current. When the difference is greater than 30A, Tstep = 0.4s, at which point the target is rapidly approached. When 10A < difference < 30A, Tstep = 1.5s, at which point the rise speed is slowed down when approaching the target.

[0098] Simultaneously, a segmented incremental step size ΔIstep is set, adaptively adjusted according to the rising interval Tstep and the rising step size ΔIstep. Preferably, the first two steps have step sizes of 0.3A, 0.6A, and 0.9A, respectively, and the subsequent step size is set to ΔIstep = min(1.2A, ΔIremain / 5), where ΔIremain / 5 is the remaining difference between the current and the target current. This avoids current surges caused by excessively large step sizes, and the maximum step size is 0.5-2A.

[0099] Preferably, when operating in a single generator state, when the charging current Ibsgs ≥ I th ​=50A, then switch from single generator state to dual generator state; at this time, only CAN1 generator and CAN2 generator activation signals are allocated Ibsgs1=Ibsgs / 8, Ibsgs2=Ibsgs / 8, output set current to make the main generator work. After the sum of the main generator voltage difference and the battery voltage meets the range, the main relay is closed, and the current is increased by 1A every 1s, so that the output current rises slowly from low to high.

[0100] When the dual generators are operating, if the charging current Ibsgs < I th =40A, then switch from dual generator state to single generator state. At this time, only the CAN1 generator activation signal is allocated Ibsgs1=Ibsgs / 4, and the output set current makes the main generator work. After the sum of the main generator voltage difference and the battery voltage meets the range, the main relay is closed, and the current is increased by 1A every 1s, so that the output current rises slowly from low to high.

[0101] Preferred options also include:

[0102] During battery charging, monitor changes in photovoltaic charging current to determine if any sudden changes in photovoltaic data occur.

[0103] If a sudden change occurs in the photovoltaic data, the generator charging setpoint Ibsgs is recalculated. The calculation formula is Ibsgs = (Io + Id - Ipv - N) × Kd, where Kd is the sudden change attenuation coefficient, with an initial value of 0.7, which increases by 0.05 in each adjustment cycle until it returns to the normal calculated value.

[0104] The adjustment cycle is set to 1 / 3 of the original cycle, the descent speed is set to 3 times the original descent amount, and a lower current limit protection is added during the descent process, with Ibsgs≥5A, to avoid the impact of restarting after the generator stops.

[0105] At the same time, the generator charging setpoint Ibsgs is controlled to decrease according to a preset adjustment cycle and decreasing speed;

[0106] The preset adjustment period is less than 1 / 2 of the generator current adjustment period before the photovoltaic data mutation; the decreasing rate is greater than twice the amount of Ibsgs decrease in each adjustment period than the amount of decrease before the photovoltaic data mutation.

[0107] To further illustrate the photovoltaic and generator coordinated control charging method of the present invention, this embodiment is based on an off-grid energy storage system:

[0108] The target battery uses a 12V lead-acid battery pack with a capacity of 100Ah. The state of charge (SOC) threshold is set at 30%, meaning that when SOC ≥ 30%, the photovoltaic system charges independently, and when SOC < 30%, the photovoltaic system and the generator charge together.

[0109] Photovoltaic module: Maximum output current 20A, dynamically affected by light intensity;

[0110] Two diesel generators: each with a rated output current of 50A, supporting single / dual generator adaptive switching.

[0111] When the battery SOC is 40% or higher than 30%, the generator stops working, and only the photovoltaic module is charged. The process is as follows:

[0112] Assuming the battery is currently discharging: Ibat = 5A, meaning it discharges 5A externally, substituting the parameters: Ix = 30A + 5A - 2A = 33A.

[0113] Since Ix = 33A ≥ 1A, the charging condition is met. The initial charging current Ipvs = 1A is set and output to the photovoltaic state machine to control the photovoltaic module to start charging at 1A.

[0114] Within 100ms after charging starts, the following was detected:

[0115] The current required charging current It = 33A, the same as Ix, since there are no other load changes;

[0116] The initial value of the actual photovoltaic output current Ipv is 1A. Calculate the current difference: Ie = It - Ipv = 33A - 1A = 32A.

[0117] Adjust Ipvs according to the formula: ΔIpv=Ipv+Ie*K, take K=0.1, ΔIpv=1A+32A*0.1=4.2A;

[0118] Ipvs=ΔIpvv+Ie*P, take P=0.05, Ipvs=4.2A+32A*0.05=5.8A.

[0119] Output Ipvs=5.8A to the photovoltaic state machine to control the photovoltaic module to output 5.8A. Repeat the above calculation (once every 100ms), and by adjusting K and P (K=0.02, P=0.01 when finally stable), make Ipv gradually approach It, and finally stabilize at 33A, if the maximum output capacity of the photovoltaic module allows.

[0120] In this embodiment, when the battery SOC is 20% or lower than 30%, the coordinated charging mode is activated, and the process is as follows:

[0121] The detected battery bus current Ibat = 8A, indicating a discharge state. According to the coordination algorithm:

[0122] During discharge, Ibsgs = Io + Ibat - N. Substituting the parameters, Ibsgs = 30A + 8A - 2A = 36A.

[0123] Based on the principle of prioritizing photovoltaics, and considering the current light intensity, assuming the maximum output capacity of photovoltaics is 15A, the preset value of Ipvs=15A is a constant and is output to the photovoltaic state machine.

[0124] Since Ibsgs = 36A < 40A, only the main generator is activated. Current adjustment method:

[0125] First assignment: 1 / 4 × Ibsgs = 9A;

[0126] Then, the current increases by 1A every 1 second, outputting 9A, 10A, 11A, ..., 36A in sequence to avoid sudden current surges impacting the battery.

[0127] If, during charging, the battery discharge current increases, causing Ibsgs to rise to 50A and remain so for 10 seconds, and the required current is ≥50A, then switch from a single generator to a dual generator.

[0128] Initial value assigned to each generator: 1 / 8 × 50A = 6.25A;

[0129] Each unit increases by 1A every 1 second until both units share 50A, or 25A each.

[0130] If Ibsgs subsequently drops to 35A and remains below 40A for 10 seconds, switch back to single generator mode and gradually increase it to 35A according to the single generator adjustment logic.

[0131] If, during the collaborative charging process, a sudden cloud cover occurs, causing the photovoltaic current to drop sharply from 15A to 5A, this indicates a data mutation. In this case, the processing procedure is to recalculate Ibsgs.

[0132] The specific formula is: Ibsgs = Io + Id - Ipv - N;

[0133] Where Id is the current battery discharge current, Ibat=8A; Ipv=5A.

[0134] Ibsgs = 30A + 8A - 5A - 2A = 31A.

[0135] The primary generator adjustment cycle is 1 second, and the decrease is 1A / cycle;

[0136] After the mutation, the adjustment period was changed to 0.5s, which is less than 1 / 2 of the original period, and the descent speed was changed to 3A / cycle, which is greater than twice the original descent amount.

[0137] Control the generator current to decrease from the current 36A to 31A at a rate of 3A / 0.5s to avoid battery voltage fluctuations.

[0138] The system achieves the following through the above method:

[0139] When SOC≥30%, the current stabilization response time for photovoltaic charging alone is <1s;

[0140] When SOC < 30%, the photovoltaic system and generator work together, and the switching between single and dual machines is smooth with no impact and the current transition is smooth.

[0141] When photovoltaic voltage suddenly changes, the generator quickly compensates, and the battery bus voltage fluctuation is controlled within ±0.5V, ensuring charging safety and efficiency.

[0142] Example 2: As Figure 2 As shown, the present invention also proposes a photovoltaic and generator coordinated control charging system, comprising:

[0143] The battery monitoring unit is used to monitor the current battery SOC status in real time. Preferably, it employs high-precision voltage and current sensors to collect battery terminal voltage and bus current data in real time. Using an SOC algorithm (in this embodiment, the ampere-hour integration method combined with open-circuit voltage correction), the current battery SOC value is calculated. The sampling frequency is 10Hz, and the SOC calculation error is ≤2%. This unit transmits the SOC status signal to the control module in real time, which serves as the basis for determining the charging mode switching. When SOC ≥ 30%, a photovoltaic-only charging command is output; when SOC < 30%, a coordinated charging command is output.

[0144] The photovoltaic charging algorithm module calculates the charging current value Ipvs that needs to be output to the photovoltaic state machine function when only the photovoltaic module is charging. Preferably, the photovoltaic charging algorithm module receives the SOC status and the current battery current Ibat output by the battery monitoring unit. First, it calculates the required charging current Ix = Io + Ibat - N using the PI algorithm, where Io = 30A and N = 2A. Then, it determines the charging start condition based on Ix. When Ix ≥ 1A, it sets the initial Ipvs = 1A. After charging starts, it collects the actual output current Ipv of the photovoltaic module and the current required charging current It every 100ms, calculates the current difference Ie = It - Ipv, and dynamically adjusts Ipvs using Ipvs = ΔIpv + Ie × P, ΔIpv = Ipv + Ie × K, where P = 0.05 and K = 0.1, and outputs it to the solar charging state machine function.

[0145] The coordinated charging algorithm module calculates the solar charging setpoint Ipvs and the generator charging setpoint Ibsgs when the generator and photovoltaic module are charging in tandem. Specifically, when activated in coordinated charging mode, the module simultaneously receives the SOC status from the battery monitoring unit, Ibat data, and the output capacity data from the photovoltaic module. On one hand, it presets a constant Ipvs based on the photovoltaic priority principle (e.g., 20A for sufficient sunlight and 10A for weak sunlight) and outputs it to the solar charging state machine function. On the other hand, it calculates the generator charging setpoint Ibsgs based on the Ibat current direction: Ibsgs = Io + Ibat - N during discharge and Ibsgs = Io - Ibat - N during charging, and outputs it to the generator state machine function. When it receives a command from the photovoltaic data change monitoring unit, it immediately recalculates and updates the setpoints according to Ibsgs = Io + Id - Ipv - N.

[0146] The solar charging state machine function is used to control the photovoltaic module to output the corresponding current to the battery to complete charging according to the solar charging set value Ipvs. Preferably, the DC / DC converter of the photovoltaic charger is controlled by a PWM pulse width modulation signal to stably adjust the output current of the photovoltaic module to the set value Ipvs, with an adjustment response time ≤50ms and current ripple ≤0.5A.

[0147] The generator state machine function controls the generator's excitation regulator and throttle actuator based on the generator charging setpoint Ibsgs, achieving precise control of the output current. When Ibsgs changes, the adjustment follows a logic of first adjusting the excitation current and then matching the throttle opening, with a current control accuracy of ≤±1A.

[0148] Preferably, the system further includes: a generator control unit;

[0149] The generator control unit is linked with the generator state machine function to monitor Ibsgs and the duration of the required current in real time. When Ibsgs < 40A, only the main generator is activated, and the current is adjusted according to the strategy of initially assigning 1 / 4 of Ibsgs, and then increasing by 1A every 1 second. When Ibsgs ≥ 40A, both generators are activated and the current is evenly distributed, and the current is adjusted according to the strategy of initially assigning 1 / 8 of Ibsgs, and then increasing by 0.8A every 0.8 seconds. It also has a state switching judgment function: when a single generator is working, if Ibsgs ≥ 50A and lasts for 10 seconds, a single-to-dual-generator switch is triggered; when both generators are working, if Ibsgs < 40A and lasts for 10 seconds, a dual-to-single-generator switch is triggered.

[0150] Preferably, the system further includes: a photovoltaic data mutation monitoring unit;

[0151] The photovoltaic data mutation monitoring unit determines whether a photovoltaic data mutation has occurred based on changes in the photovoltaic charging current. If a photovoltaic data mutation occurs, it sends a command to the coordinated charging algorithm module to recalculate the generator charging setpoint Ibsgs. Specifically, the mutation detection threshold is set to an Ipv change of ≥5A within 1 second. When a mutation is detected causing Ipv to drop sharply from 15A to 5A, a command is immediately sent to the coordinated charging algorithm module to recalculate Ibsgs, and a rapid adjustment signal is simultaneously output to the generator state machine function. This controls Ibsgs to respond quickly with an adjustment period of 0.5s and a decrease of 3A per cycle, avoiding battery voltage fluctuations.

[0152] Example 3: The present invention also proposes a battery charging drive device, wherein the device is driven by the photovoltaic and generator coordinated control charging system as described above, so as to control the generator and PV solar charger to charge the battery.

[0153] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A method for coordinated control of photovoltaic and generator charging, characterized in that, include: When the battery SOC is higher than the set value, the generator stops charging and the photovoltaic module starts charging. At this time, the photovoltaic charging algorithm module calculates the solar charging set value Ipvs that needs to be output to the solar charging state machine function. Based on the solar charging set value Ipvs, the photovoltaic module is controlled to output the corresponding current to the battery to complete the charging. When the battery SOC is lower than the set value, the generator and photovoltaic module work together to charge. At this time, the coordinated charging algorithm module calculates and outputs the solar charging set value Ipvs and the generator charging set value Ibsgs to the corresponding solar charging state machine function and generator state machine function. During generator charging, the generator charging process involves adaptive switching between single and dual generators. The calculation of the solar charging setpoint Ipvs, which needs to be output to the solar charging state machine function through the photovoltaic charging algorithm module, specifically includes: The required charging current Ix of the battery is calculated using the PI algorithm. The calculation formula is Ix=(Io+Ibat-N)×Kt×Kl; The required charging current Ix of the battery is determined: if Ix < 1A, it is determined that no charging is needed; if Ix ≥ 1A, the initial solar charging setting value Ipvs0 = 1A is set and output to the PV solar charger, so that the PV solar charger charges with a starting current of 1A; wherein, the initial solar charging setting value Ipvs0 is dynamically adjusted based on the battery SOC. Within 100ms after charging starts, calculate the current difference Ie = It - Ipv; The new solar charging setpoint Ipvs1 is calculated based on the current difference Ie, using the formula: Ipvs1 = ΔIpv + Ie × P, where ΔIpv = Ipv + Ie × K; where adjustment... The parameters P and K are adjusted to stabilize the output current of the PV solar charger. The latest solar charging setting value Ipvs1 is output to the solar charging state machine function to control the photovoltaic module to output the corresponding current to the battery. After each charging cycle, the average charging efficiency ŋ during the charging process is recorded, where ŋ = actual battery charge / total photovoltaic output power; the compensation parameter N is dynamically updated based on the average charging efficiency ŋ. In the formula, Io is the maximum allowable charging current of the battery; Ibat is the current current of the battery, positive indicates that the battery is discharging externally, and negative indicates that the battery is absorbing external current; N is the compensation parameter; Kt is the battery temperature compensation coefficient; Kl is the light intensity correction term; It is the current required charging current; and Ipv is the current output current of the PV solar charger. Within 100ms after charging starts, It and Ipv are collected every preset time, and the average current difference and the standard deviation of the current difference are calculated. If the standard deviation of the current difference is >0.5A, it is determined that there is abnormal fluctuation, and the median value is used to replace the current difference Ie. Establish an association model between P, K and Ie, and update the values of P and K every 200 ms according to the latest Ie to achieve dynamic adaptation; after each charging is completed, automatically archive the key parameters of Kt, Kl, N, P, K and the average charging efficiency of this charging, and establish a parameter-efficiency association database; when the database records reach 100 charging times, use a neural network algorithm to optimize the initial values of the parameters.

2. The photovoltaic and generator coordinated control charging method according to claim 1, characterized in that, The calculation of the coordinated charging algorithm module specifically includes: Determine whether the battery is in a discharging state or a charging state according to the current direction of the battery's current Ibat. Calculate the generator charging set value Ibsgs, and the formula is: When the battery is in the discharging state, Ibsgs = (Io + Ibat - N) × Kp; When the battery is in the charging state, Ibsgs = (Io - Ibat - N) × Kp; Based on the principle of photovoltaic priority, preset the solar charging set value Ipvs as a constant according to the maximum output capacity of the photovoltaic module, the current light intensity or the battery charging demand. Where Kp is the generator priority coefficient, and the value is dynamically adjustable within 0.6 - 1.

0.

3. The photovoltaic and generator coordinated control charging method according to claim 2, characterized in that, When the generator charges, the single generator and the dual generator can automatically switch to charge the generator, specifically including: If the generator charging set value Ibsgs < 40A, only activate one main generator, distribute the current to the main generator, and the output current of the main generator is adjusted as follows: the first assignment is 1 / 4Ibsgs, and then every 0.5s - 2s, it increases by 0.5A - 2A successively, so that the output current rises slowly from low to high; If the generator charging set value Ibsgs ≥ 40A, activate two generators at the same time, and the two generators share the current equally, and the output current of each generator is adjusted as follows: the first assignment is 1 / 8Ibsgs, and then every 0.5s - 2s, it increases by 0.5A - 2A successively, so that the output current rises slowly from low to high; Among them, when the generator operating state switches, judge the cumulative operating duration of the generator. When the cumulative operation exceeds 2 hours and the switching threshold is approaching, the current operating state is preferentially maintained.

4. The photovoltaic and generator coordinated control charging method according to claim 3, characterized in that, When the generator charges, the single generator and the dual generator can automatically switch to charge the generator, and it also includes: Define the basic switching threshold Ith0, and calculate the final switching threshold Ith according to the battery charging stage, the cumulative operating duration of the generator, and the current load fluctuation coefficient. When the generator charging set value Ibsgs < Ith, switch to the single-machine mode; When the generator charging set value Ibsgs is greater than or equal to Ith, switch to the dual-machine mode; During the switching, calculate the rising interval Tstep according to the difference between the current current and the target current, and at the same time use a piecewise increasing setting for the rising step size △Istep, and adaptively adjust according to the rising interval Tstep and the rising step size △Istep.

5. The photovoltaic and generator coordinated control charging method according to claim 4, characterized in that, It also includes: During the battery charging process, monitor the change of the photovoltaic charging current and judge whether there is a photovoltaic data mutation. If there is a photovoltaic data mutation, recalculate the generator charging set value Ibsgs, and the calculation formula is Ibsgs = (Io + Id - Ipv - N) × Kd; At the same time, the generator charging setpoint Ibsgs is controlled to decrease according to a preset adjustment cycle and decreasing speed; Wherein, the preset adjustment period is less than 1 / 2 of the generator current adjustment period before the photovoltaic data mutation; the decrease rate is greater than twice the decrease of Ibsgs in each adjustment period; Kd is the mutation attenuation coefficient; and Id is the current battery discharge current.

6. A system for a photovoltaic and generator coordinated control charging method according to any one of claims 1-5, characterized in that, include: The battery monitoring unit is used to monitor the current battery SOC status in real time; The photovoltaic charging algorithm module calculates the solar charging setpoint Ipvs that needs to be output to the solar charging state machine function when only the photovoltaic module is charging. The coordinated charging algorithm module calculates the solar charging setpoint Ipvs and the generator charging setpoint Ibsgs when the generator and photovoltaic module work together to charge. The solar charging state machine function is used to control the photovoltaic module to output the corresponding current to the battery to complete charging based on the solar charging setpoint Ipvs. The generator state machine function is used to control the generator to output the corresponding current until the battery is fully charged, based on the generator charging setpoint Ibsgs.

7. The system according to claim 6, characterized in that, Also includes: Generator control unit; The generator control unit adaptively switches between single and dual generators to charge the generator based on the generator charging setpoint Ibsgs and the generator current demand time.

8. The system according to claim 7, characterized in that, Also includes: Photovoltaic data mutation monitoring unit; The photovoltaic data mutation monitoring unit determines whether a photovoltaic data mutation has occurred based on the change in photovoltaic charging current; if a photovoltaic data mutation occurs, it sends a command to the coordinated charging algorithm module to recalculate the generator charging setpoint Ibsgs.

9. A battery charging drive device, characterized in that, The device is driven by a photovoltaic and generator coordinated control charging system as described in any one of claims 6-8, in order to control the generator and PV solar charger to charge the battery.

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