Energy scheduling and MPPT (Maximum Power Point Tracking) control system and method suitable for multi-path photovoltaic

Abstract

The invention provides an energy scheduling and MPPT (Maximum Power Point Tracking) control system and method suitable for multi-path photovoltaic. The system comprises a plurality of photovoltaic panels, a photovoltaic conversion module, a battery bus, a battery management module and a main control module, wherein the main control module integrates a sampling unit, an energy scheduling unit, an MPPT control unit and a comparator. The sampling unit obtains voltages and currents of all paths of photovoltaic and battery buses, the energy dispatching unit distributes reference power under the constraint of target charging power, the MPPT control unit drives all photovoltaic conversion modules to track the maximum power point under the constraint of the reference power, and the comparator compares a sampling electrical parameter with a safety threshold value. And the corresponding photovoltaic conversion module is turned off through the independent hardware access during overrun. According to the scheme, matching of multi-path photovoltaic power and battery requirements is achieved, the photovoltaic energy utilization rate is improved, fluctuation of a battery bus is reduced, and the fault response speed and the system safety are improved.

Description

Technical Field

[0001] This application relates to the field of photovoltaic energy dispatch, and in particular to an energy dispatch and MPPT control system and method applicable to multi-channel photovoltaic systems. Background Technology

[0002] With the popularization of photovoltaic power generation and energy storage technologies, systems that use multiple photovoltaic panels to DC charge battery packs are widely used. Existing multi-channel photovoltaic systems often adopt independent MPPT control or polling access methods for each channel. Although they aim for maximum power output of a single channel, they lack a unified power coordination mechanism, making it difficult to balance the power demand of the battery side with voltage and current constraints.

[0003] Due to differences in photovoltaic panel orientation, shading, temperature, etc., when the target charging power issued by the BMS does not match the photovoltaic power output, power mismatch is likely to occur: some branches may be overloaded or operate with limited power, resulting in low overall energy utilization; at the same time, sudden power changes or shutdowns in a single circuit may cause fluctuations in the total power of the bus, leading to voltage over-limit and affecting charging safety.

[0004] In terms of protection, existing systems mostly rely on software polling to detect anomalies and then shut down devices. The response time is in the microsecond to millisecond range, which is difficult to deal with transient faults and can easily cause the bus voltage and current to exceed the standard for a short time, increasing the risk of device damage.

[0005] Furthermore, power dispatch often employs fixed priority or simple proportional allocation, failing to comprehensively consider the real-time power generation capacity and operating status of each channel. When the output of some channels decreases, traditional dispatching struggles to reallocate power in a timely and granular manner, leading to long-term overload or surplus in some channels, resulting in low utilization and hindering PCB layout and component temperature balance. Summary of the Invention

[0006] The purpose of this application is to solve the aforementioned problems of multi-path photovoltaic power mismatch and protection lag.

[0007] According to one aspect of this application, an energy dispatch and MPPT control system suitable for multi-channel photovoltaic systems is provided for coordinating multiple photovoltaic inputs and charging a battery system, wherein the battery system includes a battery pack and a battery management module for outputting a target charging power of the battery pack. The system includes: Several photovoltaic panels connected in parallel; Several photovoltaic conversion modules are connected to each of the photovoltaic panels respectively, and are used to adjust the input voltage and input current of the corresponding photovoltaic panels; The battery busbar is connected to all the photovoltaic conversion modules and the battery pack, and is used to collect the output power of each photovoltaic conversion module and charge the battery pack. The main control module, electrically connected to each of the photovoltaic panels, each of the photovoltaic conversion modules, and the battery management module, includes: A sampling unit is used to collect electrical parameters of each photovoltaic panel and the battery busbar; An energy dispatching unit is used to allocate a reference power to each photovoltaic panel based on the target charging power and the electrical parameters of each photovoltaic panel; The MPPT control unit is used to control each photovoltaic conversion module to perform maximum power point tracking control under the corresponding reference power constraint based on the reference power and electrical parameters of each photovoltaic panel. The comparator is located inside the main control module and is electrically connected to the sampling unit and the drive control terminal of each photovoltaic conversion module. It is used to compare the electrical parameters with preset safety thresholds. When any electrical parameter exceeds the corresponding safety threshold, it bypasses the main control module control program and directly outputs a shutdown signal to the drive control terminal of the corresponding photovoltaic conversion module within a preset response time.

[0008] This application offers the following advantages: it matches the output power of multiple photovoltaic (PV) circuits with the power requirements of the battery pack, preventing overload or long-term surplus in some PV branches, improving the overall energy utilization rate of the multi-channel PV system, and reducing power and voltage fluctuations on the battery bus. Furthermore, the comparator within the main control module forms an independent hardware protection path. Compared to protection methods that rely solely on software polling, this shortens fault response time, quickly isolates fault channels, and reduces the risk of bus voltage and current overshoot and power device damage, thereby improving the operational safety and reliability of the multi-channel PV system. Attached Figure Description

[0009] The accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. The drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0010] Figure 1 This is a module connection diagram of the energy dispatch and MPPT control system described in one embodiment of this application; Figure 2 This is a topology diagram of a buck-boost DC-DC converter circuit according to an embodiment of this application; Figure 3 This is a logic block diagram of the energy scheduling and MPPT control method described in one embodiment of this application.

[0011] The following are the reference numerals: 100, Energy Dispatch and MPPT Control System; 10, Photovoltaic Conversion Module; 20, Battery Bus; 30, Main Control Module; 31, Sampling Unit; 32, Energy Dispatch Unit; 33, MPPT Control Unit; 34, Comparator; 200, Photovoltaic Panel; 300, Battery System; 310, Battery Pack; 320, Battery Management Module. Detailed Implementation

[0012] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this application. However, this application can be implemented in many different forms and is not limited to the embodiments described herein.

[0013] Please refer to Figure 1 One embodiment of this application provides an energy dispatch and MPPT control system 100 suitable for multi-channel photovoltaic systems, used to coordinate multiple photovoltaic inputs and charge a battery system 300. The photovoltaic side includes a plurality of photovoltaic panels 200 connected in parallel; the battery system 300 includes a battery pack 310 and a battery management module 320 that outputs the target charging power of the battery pack 310. The system includes: A number of photovoltaic conversion modules 10 are connected one-to-one with a number of photovoltaic panels 200 to adjust the input voltage and input current of the photovoltaic panels 200; The battery bus 20 is connected to all photovoltaic conversion modules 10, and collects the output power of each photovoltaic conversion module 10 to charge the battery pack 310. The main control module 30 is electrically connected to each photovoltaic panel 200, each photovoltaic conversion module 10, and the battery management module 320, and includes: Sampling unit 31 collects electrical parameters of each photovoltaic panel 200 and battery bus 20; The energy dispatching unit 32 allocates reference power to each photovoltaic panel 200 based on the target charging power of the battery pack 310 and the electrical parameters of each photovoltaic panel 200. MPPT control unit 33 controls each photovoltaic conversion module 10 to perform maximum power point tracking control under the corresponding reference power constraint, based on the reference power and electrical parameters corresponding to each photovoltaic panel 200. Comparator 34 is located inside the main control module 30 and is electrically connected to the sampling unit 31 and the drive control terminal of each photovoltaic conversion module 10. It compares the electrical parameters with preset safety thresholds. When any electrical parameter exceeds the corresponding safety threshold, it directly outputs a shutdown signal to the drive control terminal of the corresponding photovoltaic conversion module 10 within a preset response time.

[0014] In this embodiment, the photovoltaic conversion module 10 is disposed between the photovoltaic panel 200 and the battery bus 20, and is used to regulate the voltage and current of each photovoltaic module. The sampling unit 31 obtains the electrical parameters of the photovoltaic side and the battery bus 20 through the voltage and current sampling circuit, and sends them synchronously to the energy scheduling unit 32, the MPPT control unit 33, and the comparator 34. The energy scheduling unit 32 calculates and updates the reference power of each photovoltaic module based on the target charging power and real-time electrical parameters issued by the battery management module 320. The MPPT control unit 33 generates the control quantity of each conversion module according to the reference power and electrical parameters, and performs constrained maximum power point tracking control. The comparator 34 directly performs hardware comparison of the sampled electrical parameters with the preset safety threshold. When any electrical parameter is detected to exceed the limit, it directly outputs a shutdown signal to the drive control terminal of the corresponding photovoltaic conversion module 10 within a preset response time, without waiting for the software calculation of the main control module 30.

[0015] In one specific embodiment, the sampling unit 31 uses the ADC module built into the main control module 30 to synchronously sample the voltage and current signals of each photovoltaic panel 200 and battery bus 20 at a sampling frequency of 50kHz. This configuration enables the main control module 30 to acquire multiple sets of real-time electrical parameters within a millisecond window, providing sufficient time resolution for energy dispatching, MPPT control, and protection determination.

[0016] The comparator 34 preferably has a response time of no more than 100 ns, and more preferably about 20 ns. When any electrical parameter exceeds the corresponding safety threshold, the comparator 34 can complete the comparison and flip the output within about 20 ns, directly shutting off the drive signal of the corresponding photovoltaic conversion module 10 through an independent hardware link. Compared with the response time of tens to hundreds of microseconds of the software protection path, this hardware comparison path significantly shortens the protection delay, which is beneficial for timely isolation of the fault channel when transient faults occur on the photovoltaic side or the battery bus 20 side.

[0017] Implementing this embodiment enables unified power allocation across multiple photovoltaic channels under the target charging power constraint given by the battery management module 320. This allows each photovoltaic conversion module 10 to perform MPPT control under the reference power constraint, thereby avoiding overload or long-term surplus in some photovoltaic branches, improving overall energy utilization, and reducing bus power and voltage fluctuations. Simultaneously, by using the hardware comparator 34 to compare electrical parameters at high speed and directly shut down the drive, fault channels can be quickly isolated, reducing the risk of overvoltage, overcurrent, and device damage, and improving system safety and reliability.

[0018] In one specific embodiment, such as Figure 2 As shown, the photovoltaic conversion module is a step-up / step-down DC-DC converter circuit. Its topology includes an input filter capacitor C1, a power inductor L1, a main switch Q1, a freewheeling switch Q2, and an output filter capacitor C2, wherein: The input filter capacitor C1 is connected in parallel to the positive and negative terminals of the corresponding photovoltaic panel; One end of the power inductor L1 is electrically connected to the input filter capacitor C1 and the positive terminal of the photovoltaic panel, and the other end is connected to the switching node; One end of the main switch transistor Q1 is electrically connected to the switch node, and the other end is electrically connected to the negative electrode of the photovoltaic panel; One end of the freewheeling switch Q2 is electrically connected to the switching node, and the other end is electrically connected to the battery bus. The output filter capacitor C2 is connected in parallel to the battery bus to filter the output voltage of the photovoltaic conversion module. The control terminals of the main switch Q1 and the freewheeling switch Q2 are respectively connected to the PWM control output of the main control module.

[0019] In this embodiment, the photovoltaic conversion module adopts a buck-boost DC-DC converter topology. The input filter capacitor C1 is connected in parallel across the photovoltaic panel for filtering and local buffering. One end of the power inductor L1 is connected to the positive terminal of the photovoltaic panel, and the other end is a switching node, forming an energy conversion path together with the main switch Q1 and the freewheeling switch Q2. Q1 is connected to the negative terminal of the photovoltaic panel to control the current flow on the photovoltaic side; Q2 is connected to the battery bus to regulate energy transfer. The output filter capacitor C2 is connected in parallel to the battery bus for filtering and smoothing. Q1 and Q2 are driven by the PWM output of the main control module, causing the circuit to operate according to the control quantities of the MPPT and the scheduling unit.

[0020] This embodiment, through a buck-boost topology, can simultaneously support photovoltaic-side voltages higher or lower than the battery bus voltage, expanding the photovoltaic voltage adaptation range. C1, C2, and L1 work together to smooth the voltage and current waveforms on both sides, reducing the impact of power fluctuations on the bus and battery pack, and improving the stability and conversion efficiency of multi-path photovoltaic energy transmission.

[0021] like Figure 3 As shown, the present invention also provides an energy dispatch and MPPT control method applicable to multi-channel photovoltaic systems, applied to the energy dispatch and MPPT control system described above, comprising: S10. Collect the electrical parameters of the photovoltaic panel and the battery bus. The electrical parameters of the photovoltaic panel include the input voltage and input current, and the electrical parameters of the battery bus include the total output voltage and total output current. The electrical parameters of the photovoltaic panel and the battery bus are obtained by the sampling unit in the main control module through voltage and current sampling circuits, and are synchronously sent to the main control module at a preset sampling frequency for subsequent energy dispatch and MPPT control.

[0022] S20. Obtain the target charging power of the battery pack output by the battery management module. The main control module obtains the currently allowed target charging power of the battery pack through the communication bus with the battery management module, which is used as the upper limit of the power constraint for the entire system.

[0023] S30. Based on the target charging power and the electrical parameters of each photovoltaic panel, the energy dispatch unit allocates reference power to each photovoltaic panel. The energy dispatch unit, having mastered the target charging power and the real-time electrical parameters of each photovoltaic panel, calculates and allocates the reference power for each photovoltaic panel based on its current power output and operating status, and then sends the reference power to the corresponding photovoltaic conversion module.

[0024] S40. The MPPT control unit controls the photovoltaic conversion modules corresponding to each photovoltaic panel to perform maximum power point tracking control under the corresponding reference power constraints. Under the constraint of their respective reference power, the MPPT control unit performs maximum power point tracking control on each photovoltaic conversion module, converting the reference power into the corresponding duty cycle or current and voltage control quantities, so that each photovoltaic module is as close as possible to its maximum power point without exceeding the scheduling constraints.

[0025] Implementing this embodiment enables unified power allocation for multiple photovoltaic (PV) circuits under the target charging power constraint given by the battery management module. Based on this, constrained MPPT control is performed on each PV conversion module, thereby avoiding system power mismatch caused by a single PV circuit pursuing its own maximum power. This improves the overall energy utilization of multiple PV circuits, reduces power and voltage fluctuations on the battery bus side, and better meets the safe charging requirements of the battery pack.

[0026] Furthermore, the method also includes: S50. A comparator located inside the main control module compares the electrical parameters with preset safety thresholds in real time. When any electrical parameter exceeds the corresponding safety threshold, the comparator directly outputs a shutdown signal to the drive control terminal of the corresponding photovoltaic conversion module within a preset response time. The comparator is integrated inside the main control module, and its input terminal directly receives the voltage and current signals output by the sampling unit. The safety threshold can be set through a register or an external reference circuit. The comparator performs real-time hardware comparison between the electrical parameters and the threshold. Once an over-limit is detected, a shutdown signal is sent to the drive control terminal through an independent hardware protection path, thereby bypassing the software calculation and control process and realizing direct hardware shutdown of the abnormal channel.

[0027] Implementing this embodiment enables rapid detection and shutdown of anomalies such as overvoltage and overcurrent on the photovoltaic side and battery bus side without relying on the main control module software polling and calculation. This shortens the protection response time, reduces transient overshoot of battery bus voltage and current, and lowers the risk of power device damage and system failure, thereby improving the operational safety and reliability of multi-channel photovoltaic systems.

[0028] Furthermore, prior to S30, the system operation process is managed through a low-speed state machine within the main control module. This low-speed state machine executes cyclically at a low frequency to determine and prepare the system operating conditions before entering power distribution and MPPT control. Specifically, this includes: S60. Compare the electrical parameters of the photovoltaic panel and battery bus with the preset safety thresholds, and perform photovoltaic insulation monitoring to determine if a fault exists. The state machine calls the voltage and current of the photovoltaic panel and battery bus obtained by the sampling unit, compares them with the preset safety thresholds, and combines the photovoltaic insulation monitoring results to comprehensively determine whether there is a fault such as overvoltage, overcurrent, or grounding.

[0029] S61. If no fault exists, check if the battery management module is online. If so, set the target charging power and maximum charging voltage according to the communication information from the battery management module. If not, set the target charging power and maximum charging voltage according to the default parameters. If no fault exists, the state machine checks if the battery management module is online. If online, read the target charging power and maximum charging voltage parameters sent by the module and write them into the main control module's internal register as the basis for subsequent energy scheduling and voltage constraints. If offline, call the default parameters to ensure that the system still has a controlled startup strategy when the BMS malfunctions.

[0030] S62. Determine whether the input voltage of each photovoltaic panel is within the preset start-up voltage range. If so, control the photovoltaic conversion module corresponding to that photovoltaic panel to switch from the off state to the closed-loop operation state. If not, keep the photovoltaic conversion module corresponding to that photovoltaic panel in the off state. The state machine checks whether the input voltage of each photovoltaic panel is within the preset start-up voltage range one by one. If the condition is met, an enable command is issued to the corresponding photovoltaic conversion module to switch it from the off state to the closed-loop operation state; otherwise, keep that path off to avoid blindly starting power conversion when the photovoltaic voltage is too low or unstable.

[0031] This embodiment utilizes a low-speed state machine to uniformly determine fault states, BMS online status, and startup conditions for each photovoltaic module before energy dispatch and MPPT control, achieving an orderly power-on process of "self-check first, then startup." This avoids directly entering high-power operation during faults or BMS outages, reducing the impact on the battery bus and power devices. It also prevents premature loop closure when the photovoltaic voltage is below the startup range, reducing oscillations and repeated start-stop cycles, thereby improving the stability and safety of the startup phase and providing a reliable prerequisite for subsequent dispatch and control.

[0032] Furthermore, after S60, it also includes: S63. If a fault exists, the fault recovery process begins. Faults include photovoltaic panel faults and / or battery bus faults. Faults are determined jointly by the threshold comparison in S60 and photovoltaic insulation monitoring. Once a fault is determined, the system classifies it as a photovoltaic panel fault or a battery bus fault based on its location and enters the corresponding fault recovery process. Fault recovery includes: S64. When the fault is a photovoltaic panel fault, the drive of the photovoltaic conversion module corresponding to the faulty photovoltaic panel is shut down, the reference power of the faulty channel is set to zero, and the reference power of the remaining photovoltaic panels is redistributed through the energy dispatch unit to ensure that the total power change on the battery bus does not exceed the preset power fluctuation threshold. For photovoltaic panel faults, the main control module shuts down the drive of the corresponding photovoltaic conversion module, sets the reference power of the channel to zero, and removes it from the list. At the same time, the energy dispatch unit redistributes the reference power among the remaining photovoltaic panels, limiting the total power change of the battery bus to a preset power fluctuation threshold during redistribution to avoid excessive single adjustment.

[0033] S65. During the fault recovery process, the electrical parameters of the faulty channel and the battery bus are continuously collected and compared with the corresponding safety thresholds. When the electrical parameters of the faulty channel are detected to be within the corresponding safety threshold range within a preset number of consecutive samplings and the photovoltaic insulation monitoring is passed, it is determined that the fault of the faulty channel has been recovered. The fault recovery process adopts a continuous monitoring method. The system continuously collects the voltage, current, and other electrical parameters of the faulty channel and the battery bus and compares them with the corresponding safety thresholds, while also combining the photovoltaic insulation monitoring results. Only when the electrical parameters of the faulty channel are within the safety threshold range within a preset number of consecutive samplings and the insulation detection is normal, is it determined that the fault of the channel has been recovered.

[0034] S66. After determining that the fault has been restored, the energy dispatch unit increases the reference power of the faulty channel according to a preset adjustment slope, and correspondingly decreases the reference power of other photovoltaic panels, ensuring that the total power on the battery bus does not fluctuate within the power fluctuation threshold throughout the restoration process. After the fault is restored, the energy dispatch unit gradually increases the reference power of the channel according to a preset adjustment slope, and simultaneously decreases the reference power of other photovoltaic panels proportionally, ensuring that the total power of the battery bus is always constrained by the power fluctuation threshold during the restoration process, achieving a smooth transition.

[0035] In this embodiment, when a photovoltaic (PV) channel fails, the corresponding PV conversion module is shut down and its reference power is set to zero, thus promptly isolating the faulty channel. Simultaneously, the reference power of the remaining channels is redistributed in a controlled manner, limiting the power surge to the battery bus within a preset range and reducing the disturbance to the bus voltage and current caused by the fault. During the fault recovery phase, continuous sampling for stability assessment and PV insulation monitoring are used in conjunction to prevent erroneous recovery or premature grid connection. Once the channel stabilizes, its reference power is gradually increased according to a slope, while the reference power of other channels is simultaneously restored, allowing the system to smoothly transition from degraded operation to normal operation. This improves system safety and stability while restoring the power generation contribution of the faulty channel, enhancing the overall availability and energy utilization of the multi-channel PV system.

[0036] Furthermore, S63 and later also include: S67. When the fault is identified as a battery bus fault, the energy dispatch unit gradually reduces the reference power corresponding to each photovoltaic panel according to a preset decreasing slope until it does not exceed the preset minimum safe power. Simultaneously, it controls the drives of each photovoltaic conversion module to gradually reduce their duty cycles or shut down sequentially, causing the total output power on the battery bus to decrease smoothly and guiding the battery bus voltage and total output current back to a safe range. When a battery bus fault is determined, the main control module, through the energy dispatch unit, gradually lowers the reference power of each photovoltaic panel according to a preset decreasing slope until it does not exceed the preset minimum safe power. Simultaneously, it controls the drives of each photovoltaic conversion module to gradually reduce their duty cycles or shut down sequentially, causing the total output power of the battery bus to decrease smoothly at a controlled slope, guiding the bus voltage and total output current back to a safe range.

[0037] S68. Continuously collect the battery bus voltage, total output current, and photovoltaic insulation status, and compare the battery bus electrical parameters with the corresponding safety thresholds. When the battery bus voltage and total output current are both within the corresponding safety threshold range within a preset number of consecutive samplings, and the photovoltaic insulation monitoring passes, the battery bus fault is determined to be resolved. The system continuously collects the battery bus voltage, total output current, and photovoltaic insulation status, and compares them with the corresponding safety thresholds. Only when the voltage and current are both within the safe range within a preset number of consecutive samplings, and the insulation monitoring is normal, is the battery bus fault determined to be resolved.

[0038] S69. The energy dispatch unit gradually increases the reference power of each photovoltaic panel according to a preset ramp rate and redistributes the reference power among multiple photovoltaic panels, ensuring that the total power on the battery bus does not change beyond a preset power fluctuation threshold during the recovery process. The energy dispatch unit gradually increases the reference power of each photovoltaic panel according to a preset ramp rate and redistributes the power among multiple photovoltaic panels. Throughout the recovery process, the preset power fluctuation threshold constrains the change in the total power of the battery bus, achieving a gradual increase and smooth redistribution.

[0039] In implementing this embodiment, when a battery bus fault occurs, the output power of multiple photovoltaic systems is smoothly reduced by lowering the slope of the reference power and duty cycle, so that the bus voltage and current fall back in an orderly manner, avoiding the severe impact of a one-time disconnection. During the recovery phase, the reference power of multiple photovoltaic systems is gradually increased by continuously sampling and judging stability, and the photovoltaic output is gradually restored under the premise of ensuring that the bus power fluctuation is controlled, reducing the risk of system oscillation, improving the stability and safety under fault scenarios, and taking into account the recovery of photovoltaic energy utilization after the fault.

[0040] In one specific embodiment, the preset number of consecutive samples is determined based on the sampling frequency and the desired stability determination time. For example, when the sampling frequency is 50kHz, the number of consecutive samples can be set to 5 to 10, corresponding to a stability determination time of approximately 100 to 200μs. This setting can ensure that the protection judgment has a certain ability to resist transient spike interference while taking into account the response speed of fault recovery and bus restart.

[0041] Furthermore, the S40 includes: S41. Determine the initial duty cycle based on the photovoltaic panel and battery bus voltage, and initiate current-type MPPT control. The main control module calculates the initial duty cycle of the main switch of the photovoltaic conversion module based on the collected photovoltaic panel input voltage and battery bus voltage, provides a suitable starting operating point, and initiates current-type maximum power point tracking control.

[0042] S42. The system switches between the perturbation observation method and the incremental conductance method for photovoltaic operating point tracking based on the power change. The main control module compares the photovoltaic input power change in adjacent sampling periods with a first preset threshold. If the change is large, the perturbation observation method is used for a larger step size power point search; if the change is small, the incremental conductance method is used for a smaller step size fine tracking.

[0043] S43. When an open-circuit voltage region is detected, a forced left shift is performed and the step size is accumulated. When the photovoltaic input current is detected to be too small and the changes in voltage and current are both less than the second preset threshold, it is determined that the current operating point is in or close to the photovoltaic open-circuit voltage region. The operating point is forced to "shift left" in the direction of increasing current, and the left shift step size is accumulated to accelerate the exit from the open-circuit voltage region.

[0044] S44. If the input power exceeds the reference power, a forced right shift is executed, and the MPPT and left shift logic are skipped. When the input power is greater than the reference power, the control operating point is shifted "right" in the direction of power reduction, and the aforementioned power point tracking and forced left shift logic are skipped during this control cycle to prioritize satisfying the reference power constraint.

[0045] S45. The photovoltaic input current loop and the battery bus voltage loop compete for output, and the final duty cycle is determined by the low-select module. The main control module converts the target operating point determined by power point tracking into a photovoltaic input current reference value. The photovoltaic input current loop generates a current control quantity corresponding to the duty cycle of the main switch, and the battery bus voltage loop generates a voltage control quantity based on the deviation between the bus voltage and the maximum allowable charging voltage. The low-select competition module selects between the two to obtain the final duty cycle control quantity.

[0046] This embodiment achieves rapid search and precise locking of the photovoltaic operating point by switching between the perturbation observation method and the incremental conductance method driven by power change. Forced left-shift logic prevents the operating point from erroneously remaining near the open-circuit voltage, while forced right-shift logic promptly reduces power when the input power exceeds the reference power, thus balancing MPPT speed and steady-state accuracy under reference power constraints. Simultaneously, the competitive selection between the current loop and voltage loop ensures that the photovoltaic side follows the maximum power point while being limited by the maximum allowable charging voltage of the bus, which helps improve photovoltaic energy utilization and maintain the safe and stable bus voltage.

[0047] Optionally, S30 includes: S31. Upon initial power-on of the system, the target charging power is allocated as the initial reference power for each photovoltaic panel and sent to the MPPT control unit. During initial power-on operation, the main control module reads the target charging power provided by the battery management module, allocates it among the photovoltaic panels according to preset rules, obtains the initial reference power for each photovoltaic panel, and sends it as a constraint to the corresponding MPPT control unit as the target value for subsequent power point tracking.

[0048] S32. Periodically detect whether the target charging power changes and calculate the power difference. During normal system operation, the main control module detects whether the target charging power changes at a set period. If it changes, it calculates the power difference based on the target charging power before and after the change, which is used to guide the direction and total amount of increase or decrease of each reference power.

[0049] S33. If the power difference is less than zero, the reference power is reduced according to a preset priority until the difference is offset, and the corresponding conversion module is shut down according to the lower limit. When the power difference is less than zero, the main control module reduces the reference power of each photovoltaic panel sequentially according to a preset priority, and accumulates the reduction until the total offsets the power difference. When the reference power of a certain line drops to a preset lower limit, the corresponding photovoltaic conversion module is shut down, realizing orderly load shedding of each line.

[0050] S34. If the power difference is greater than zero, the reference power is increased according to a preset priority until the difference is offset. The priority is determined based on the photovoltaic channel number, PCB layout, and / or circuit temperature rise. When the power difference is greater than zero, the main control module increases the reference power of each photovoltaic panel sequentially according to a preset priority order until the total increase offsets the power difference. The priority order can be determined based on the photovoltaic channel number, PCB layout, and / or circuit temperature rise to prioritize the upgrading or activation of specific channels.

[0051] In this embodiment, when the target charging power changes, the reference power of each channel is increased or decreased according to priority based on the power difference, enabling multiple photovoltaic systems to quickly follow the power demand of the battery side. By setting a lower limit and controlling each channel to turn off / on sequentially, sudden changes in bus power caused by a large-scale switchover are avoided. The priority order considers factors such as channel number, PCB layout, and temperature rise, ensuring that while meeting the total power demand, it also considers device heat dissipation and balanced PCB layout, improving the stability and reliability of the multi-photovoltaic system during dynamic power adjustment.

[0052] Furthermore, S30 also includes periodic scheduling of the reference power within multiple photovoltaic systems, specifically including: S35. When the internal scheduling cycle arrives, the photovoltaic panels are marked as having spare capacity or no spare capacity based on the comparison between the actual input power and the reference power. When the preset internal scheduling cycle arrives, the main control module calculates the actual input power of each photovoltaic panel based on the sampled data and compares it with the corresponding reference power according to a first preset ratio. If the actual input power of a certain channel is not lower than the product of the reference power and the ratio, it is marked as a "spare capacity" photovoltaic panel; otherwise, it is marked as a "no spare capacity" photovoltaic panel, in order to distinguish channels with room for improvement, those approaching the upper limit of capacity, or those with power gaps.

[0053] S36. When the number of photovoltaic panels with spare capacity is not zero and is not equal to the total number of photovoltaic panels, the power gap of the non-spare capacity is summed and distributed proportionally to the photovoltaic panels with spare capacity, while a maximum power limit is imposed on them. When some photovoltaic panels have spare capacity but not all of them do, the main control module sums the difference between the reference power and the actual power of each photovoltaic panel without spare capacity to obtain the total power difference, and distributes this difference to the photovoltaic panels with spare capacity according to the second preset ratio. By increasing their reference power, the system power gap is compensated, and a maximum power limit is imposed on the reference power of the photovoltaic panels with spare capacity to avoid exceeding the safe operating range.

[0054] S37. Distribute the remaining power deficit proportionally to the photovoltaic panels with no spare capacity, adjust their reference power and apply a maximum power limit to ensure that the sum of the reference power of multiple photovoltaic channels remains equal to the target charging power. Distribute the remaining portion of the total power difference to the photovoltaic panels with no spare capacity according to a third preset ratio, adjust their reference power and apply a maximum power limit to them as well, thereby achieving a more refined secondary balance of the reference power of each photovoltaic channel while keeping the sum of the reference power of multiple photovoltaic channels unchanged.

[0055] In this embodiment, with the total target charging power remaining constant, channels with and without power are automatically distinguished periodically based on the deviation between the actual power and reference power of each photovoltaic panel. The power deficit generated by the channels without power is preferentially allocated to photovoltaic panels with power, and a maximum power constraint is applied to the reference power of each channel. This improves the overall utilization rate of the photovoltaic array while meeting the power requirements of the battery side and mitigating long-term overload or surplus phenomena in individual channels. This approach balances energy utilization, device temperature rise, and panel layout balance, improving the long-term operating efficiency and reliability of multi-channel photovoltaic systems.

[0056] In one specific embodiment, the first preset ratio is set to 0.95, meaning that when the actual input power of the photovoltaic panel is greater than or equal to 95% of the reference power, it is marked as a photovoltaic panel with spare capacity; when it is less than 95%, it is marked as a photovoltaic panel with no spare capacity. This ratio can be adjusted according to the response speed of the control system and the internal scheduling cycle.

[0057] In another specific embodiment, both the second and third preset ratios can be set to 0.5, which is used to roughly evenly distribute the total power difference between photovoltaic panels with and without power. The preset power fluctuation threshold can be determined based on the allowable voltage and current fluctuation range of the battery bus and the system power level, for example, taking a certain percentage of the target charging power, so as to balance bus stability and power adjustment flexibility.

[0058] The above embodiments are merely illustrative of several implementations of this application. For those skilled in the art, numerous modifications and improvements can be made without departing from the concept of this application, and all such modifications and improvements fall within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the appended claims.

Claims

1. A power dispatch and MPPT control system suitable for multi-channel photovoltaic systems, used to coordinate multiple photovoltaic inputs and charge a battery system, the battery system including a battery pack and a battery management module for outputting a target charging power of the battery pack, characterized in that, The system includes: Several photovoltaic panels connected in parallel; Several photovoltaic conversion modules are connected to each of the photovoltaic panels respectively, and the input voltage and input current of the corresponding photovoltaic panels are adjusted; The battery busbar is connected to all the photovoltaic conversion modules and the battery pack, collecting the output power of each photovoltaic conversion module and charging the battery pack. The main control module, electrically connected to each of the photovoltaic panels, each of the photovoltaic conversion modules, and the battery management module, includes: The sampling unit collects the electrical parameters of each photovoltaic panel and the battery busbar. The energy dispatching unit allocates reference power to each photovoltaic panel based on the target charging power and the electrical parameters of each photovoltaic panel; The MPPT control unit controls each photovoltaic conversion module to perform maximum power point tracking control under the corresponding reference power constraint, based on the reference power and electrical parameters of each photovoltaic panel. The comparator is located inside the main control module and is electrically connected to the sampling unit and the drive control terminal of each photovoltaic conversion module. It compares the electrical parameters with a preset safety threshold. When any electrical parameter exceeds the corresponding safety threshold, it bypasses the main control module control program and directly outputs a shutdown signal to the drive control terminal of the corresponding photovoltaic conversion module within a preset response time.

2. The energy dispatching and MPPT control system according to claim 1, characterized in that, The photovoltaic conversion module is a step-up / step-down DC-DC converter circuit. Its topology includes an input filter capacitor C1, a power inductor L1, a main switch Q1, a freewheeling switch Q2, and an output filter capacitor C2, wherein: The input filter capacitor C1 is connected in parallel to the positive and negative terminals of the corresponding photovoltaic panel; One end of the power inductor L1 is electrically connected to the input filter capacitor C1 and the positive terminal of the photovoltaic panel, and the other end is a switching node; One end of the main switch transistor Q1 is electrically connected to the switch node, and the other end is electrically connected to the negative electrode of the photovoltaic panel; One end of the freewheeling switch Q2 is electrically connected to the switching node, and the other end is electrically connected to the battery bus. The output filter capacitor C2 is connected in parallel to the battery bus; The control terminals of the main switch Q1 and the freewheeling switch Q2 are respectively connected to the PWM control output of the main control module.

3. A method for energy dispatch and MPPT control applicable to multi-channel photovoltaic systems, applied to the energy dispatch and MPPT control system as described in claim 2, characterized in that, include: S10. Collect the electrical parameters of the photovoltaic panel and the battery bus, where the photovoltaic panel electrical parameters include the input voltage and input current, and the battery bus electrical parameters include the total output voltage and total output current. S20. Obtain the target charging power output by the battery management module; S30. Based on the target charging power and the electrical parameters of each photovoltaic panel, a reference power is allocated to each photovoltaic panel through the energy dispatching unit; S40. The MPPT control unit controls the photovoltaic conversion module corresponding to each photovoltaic panel to perform maximum power point tracking control under the corresponding reference power constraint.

4. The energy dispatching and MPPT control method according to claim 3, characterized in that, The method also includes: S50. The electrical parameters are compared with a preset safety threshold in real time by a comparator located inside the main control module. When any electrical parameter exceeds the corresponding safety threshold, the comparator directly outputs a shutdown signal to the drive control terminal of the corresponding photovoltaic conversion module within a preset response time.

5. The energy dispatching and MPPT control method according to claim 3, characterized in that, Prior to S30, the system operation process is managed through a low-speed state machine within the main control module, specifically including: S60. Compare the electrical parameters of the photovoltaic panel and battery bus with the preset safety threshold, and perform photovoltaic insulation monitoring to determine whether there is a fault. S61. If there is no fault, check if the battery management module is online. If it is online, set the target charging power and maximum charging voltage according to its communication information; otherwise, set the default parameters. S62. Determine whether the input voltage of each photovoltaic panel is within the preset start-up voltage range. If the condition is met, control the corresponding photovoltaic conversion module to switch from the off state to the closed-loop operation state.

6. The energy dispatching and MPPT control method according to claim 5, characterized in that, Following S60, the following is also included: S63. If a fault exists, proceed with the fault recovery process, where the fault includes photovoltaic panel fault and / or battery bus fault. S64. When a photovoltaic panel fails, the reference power of the faulty channel is set to zero, and the reference power of the remaining photovoltaic panels is redistributed through the energy dispatch unit so that the total power change of the battery bus does not exceed the preset power fluctuation threshold. S65. Continuously collect the electrical parameters of the fault channel and the battery bus and compare them with the corresponding safety threshold. When the electrical parameters of the fault channel are within the safety threshold range within the preset number of consecutive samplings and the photovoltaic insulation monitoring passes, the fault is determined to be recovered. S66. The energy dispatching unit adjusts the slope according to a preset value to increase the reference power of the faulty channel and correspondingly decreases the reference power of other photovoltaic panels.

7. The energy dispatching and MPPT control method according to claim 6, characterized in that, Following S63, the following is also included: S67. When the fault is a battery bus fault, the reference power of each photovoltaic panel is reduced to no higher than the preset minimum safe power according to the preset decline slope. At the same time, the drive of each photovoltaic conversion module is controlled to gradually reduce the duty cycle or shut down in sequence, so that the battery bus voltage and total output current fall back to the safe range. S68. Continuously collect battery bus voltage, total output current and photovoltaic insulation status, and compare them with the corresponding safety thresholds; when the battery bus voltage and total output current are both within the safety threshold range within the preset number of consecutive samplings and the photovoltaic insulation monitoring passes, the battery bus fault is determined to be resolved. S69. The reference power of each photovoltaic panel is gradually increased by the energy dispatching unit according to the preset rising slope, and the reference power is redistributed among the multiple photovoltaic panels.

8. The energy dispatching and MPPT control method according to claim 3, characterized in that, S40 includes: S41. Determine the initial duty cycle based on the voltage of the photovoltaic panel and the battery bus, and start the current-type MPPT control. S42. Photovoltaic operating point tracking is performed based on the power change disturbance observation method and the incremental conductivity method. S43. When an open-circuit voltage region is detected, perform a forced left shift and accumulate the step size; S44. If the input power exceeds the reference power, a forced right shift is executed, and the MPPT and left shift logic are skipped. S45. The photovoltaic input current loop competes with the battery bus voltage loop for output, and the final duty cycle is determined by the low selection module.

9. The energy dispatching and MPPT control method according to claim 3, characterized in that, S30 includes: S31. When the system is powered on for the first time, the target charging power is allocated as the initial reference power of each photovoltaic panel and sent to the MPPT control unit. S32. Periodically detect whether the target charging power changes and calculate the power difference; S33. If the power difference is less than zero, reduce the reference power according to the preset priority until the difference is offset, and shut down the corresponding conversion module according to the lower limit. S34. If the power difference is greater than zero, the reference power is increased according to the preset priority until the difference is offset; the priority is determined according to the photovoltaic channel number, PCB layout and / or circuit temperature rise.

10. The energy dispatching and MPPT control method according to claim 9, characterized in that, The S30 further includes periodically scheduling the reference power within the multiple photovoltaic channels, specifically including: S35. When the internal scheduling cycle arrives, the photovoltaic panels are marked as having spare capacity or no spare capacity based on the comparison between the actual input power and the reference power. S36. When the number of photovoltaic panels with spare capacity is not zero and is not equal to the total number of photovoltaic panels, sum up the power gaps of the unspared power and allocate them proportionally to the photovoltaic panels with spare capacity, while imposing a maximum power limit on them. S37. Distribute the remaining power deficit proportionally to the photovoltaic panels with no spare capacity, adjust their reference power and apply a maximum power limit so that the sum of the reference power of the multiple photovoltaic panels remains equal to the target charging power.

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