Photovoltaic power generation control methods for new energy commercial vehicles

Abstract

This invention discloses a photovoltaic power generation control method for new energy commercial vehicles, belonging to the field of new energy vehicle technology. It mainly divides the power battery into two battery zones, A and B, which independently drive the vehicle, and introduces a dynamic redundancy balancing control strategy: during the process of discharging in zone A and charging zone B with photovoltaic power, the dynamic power difference ΔP between the load power and the photovoltaic power is calculated in real time; when ΔP exceeds a preset impact threshold, the battery zone switching is forcibly paused, and the A and B zones are controlled to output in parallel instantaneously to buffer the power impact. Simultaneously, based on the historical fluctuation trend of ΔP, the discharge cutoff threshold and the energy replenishment completion threshold are dynamically adjusted to reserve more safety margin during periods of fluctuation. This invention solves the problems of abrupt switching and poor anti-fluctuation ability in existing technologies through a dual mechanism of instantaneous response and trend adaptation, achieving efficient and smooth utilization of photovoltaic energy and significantly improving the vehicle's range stability and system robustness under different operating conditions.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and in particular to a photovoltaic power generation control method for new energy commercial vehicles. Background Technology

[0002] Currently, the application scenarios for pure e-commerce vehicles are becoming increasingly widespread, but users' range anxiety and demand for reducing overall vehicle energy consumption are becoming increasingly strong. Utilizing the large space above the cargo box and cab of commercial vehicles to install photovoltaic power generation panels to provide auxiliary energy for the vehicles has become an important direction for technological development.

[0003] However, photovoltaic power generation is inherently intermittent and fluctuating, and its coupling with the complex dynamic operating conditions of vehicles has always been a challenge in the industry. Existing technologies propose switching between various modes, such as driving discharge, plug-in charging, and energy recovery, by detecting the vehicle's charging and discharging status, and calculating the corresponding photovoltaic power generation. While this approach refines the mode division, its switching logic is mainly based on static vehicle status judgments, lacking the dynamic response capability to instantaneous fluctuations in photovoltaic power and sudden load changes. The switching process may be abrupt, affecting system stability.

[0004] Another existing technological approach proposes a fixed master-slave division of labor, with one battery pack providing power and another storing energy. The photovoltaic system charges the second battery pack, which in turn replenishes the first. While this solution achieves functional separation, the energy undergoes a secondary conversion, resulting in efficiency losses. Furthermore, the fixed roles of the two battery packs prevent flexible adjustments based on real-time operating conditions and photovoltaic fluctuations, limiting their adaptability to photovoltaic volatility.

[0005] In addition, the industry has introduced the concept of dual batteries, which control the batteries to replenish the power battery or low-voltage electrical appliances based on the motor's start-up or shutdown status, and the power battery to reverse charge when the power is insufficient. Although this solution considers various operating conditions, its core control still focuses on the "availability" and "high / low" of the power, failing to solve the problem of instantaneous power imbalance between photovoltaic output and load demand during sudden changes in sunlight. The system may still experience voltage drops due to power shortages.

[0006] In summary, existing technologies either rely on extensive mode switching or fixed energy flow, neither of which fundamentally resolves the contradiction between efficient photovoltaic energy utilization and vehicle power supply stability in complex dynamic environments. It is evident that there is a general lack of an adaptive control strategy that can dynamically sense photovoltaic fluctuations and load impacts and provide flexible buffering through battery area collaboration. Summary of the Invention

[0007] In view of the above, the present invention aims to provide a photovoltaic power generation control method for new energy commercial vehicles to solve the aforementioned technical problems.

[0008] The technical solution adopted in this invention is as follows:

[0009] This invention provides a photovoltaic power generation control method for new energy commercial vehicles, including: dividing the vehicle's power battery into a first battery area and a second battery area, wherein both the first battery area and the second battery area are configured to have the ability to independently drive the vehicle to work normally;

[0010] Obtain the first charge level of the first battery region and the second charge level of the second battery region;

[0011] When the first battery charge is greater than the second battery charge, the first battery area is controlled to discharge and supply power to the whole vehicle, and the photovoltaic power generation module is controlled to charge the second battery area.

[0012] The discharge power of the first battery area and the charging power of the photovoltaic power generation module are monitored in real time, and the dynamic power difference ΔP is calculated.

[0013] Based on the real-time changing trend of the dynamic power difference ΔP, the preset discharge cutoff threshold and energy replenishment completion threshold are dynamically adjusted.

[0014] During the process of the first battery area discharging and supplying energy to the whole vehicle, the first battery charge and the second battery charge are monitored in real time;

[0015] When the first battery level drops to the discharge cutoff threshold and the second battery level rises to the recharge completion threshold, the system switches to allow the second battery area to discharge and power the vehicle, and controls the photovoltaic power generation module to charge the first battery area.

[0016] In at least one possible implementation, the real-time monitoring of the discharge power of the first battery region and the charging power of the photovoltaic power generation module, and the calculation of the dynamic power difference ΔP, specifically includes:

[0017] The dynamic power difference ΔP(t) is calculated using the following formula: ΔP(t) = P_load(t) - P_pv(t), where P_load(t) is the real-time load power of the vehicle and P_pv(t) is the real-time power generation of the photovoltaic module.

[0018] In at least one possible implementation, the control method further includes:

[0019] When the dynamic power difference ΔP(t) is detected to exceed the preset power impact threshold, the role switching between the first battery area and the second battery area is temporarily frozen under the preset duration parameter, and the first battery area and the second battery area are controlled to output in parallel instantaneously to jointly power the vehicle load.

[0020] In at least one possible implementation, dynamically adjusting the preset discharge cutoff threshold and recharging completion threshold based on the real-time changing trend of the dynamic power difference ΔP includes:

[0021] Record and analyze the change curve of the dynamic power difference ΔP within a preset historical time period to identify the fluctuating and stable periods of photovoltaic power generation;

[0022] During the fluctuating period, the discharge cutoff threshold is adjusted upward from the first preset value, and the recharging completion threshold is adjusted downward from the second preset value; during the stable period, the discharge cutoff threshold is restored to the first preset value, and the recharging completion threshold is restored to the second preset value.

[0023] In at least one of the possible implementations, the first preset value of the discharge cutoff threshold is 15%-20% of the total power, and the adjusted range is 25%-30%; the second preset value of the recharging completion threshold is 85%-90% of the total power, and the adjusted range is 75%-80%.

[0024] In at least one possible implementation, after the control switch is initiated by the second battery area discharging power to the vehicle, it further includes:

[0025] When the dynamic power difference between the discharge power of the second battery area and the charging power of the photovoltaic power generation module for the first battery area is detected to exceed the power surge threshold again, the steps of pausing switching and parallel output are repeated.

[0026] Compared with existing technologies, the main design concept of this invention lies in enabling the photovoltaic power generation system to smoothly cope with various dynamic operating conditions and achieve efficient and stable energy utilization through battery partition management and dynamic redundancy balancing control strategies. Specifically, the power battery is divided into two battery zones, A and B, which independently drive the vehicle, and a dynamic redundancy balancing control strategy is introduced: during the process of discharging in zone A and charging zone B with photovoltaic power, the dynamic power difference ΔP between the load power and the photovoltaic power is calculated in real time; when ΔP exceeds a preset impact threshold, the battery zone switching is forcibly suspended, and the A and B zones are controlled to output in parallel instantaneously to buffer the power impact in a coordinated manner. At the same time, based on the historical fluctuation trend of ΔP, the discharge cutoff threshold and the energy replenishment completion threshold are dynamically adjusted to reserve more safety margin during fluctuation periods. This invention constructs a complete closed-loop control strategy from instantaneous response to trend adaptation by introducing a coordinated buffering mechanism based on dynamic power difference monitoring and an adaptive threshold adjustment mechanism based on fluctuation trends. Compared with existing technologies, this invention is the first to achieve flexible buffering of photovoltaic fluctuations and load impacts in the field of commercial vehicle photovoltaic control, significantly improving the robustness and energy utilization efficiency of the system. This is an innovative concept that is difficult for those skilled in the art to directly derive from existing technologies. Attached Figure Description

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0028] Figure 1 This is a schematic diagram of a photovoltaic power generation control method for new energy commercial vehicles provided in an embodiment of the present invention. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0030] This invention proposes an embodiment of a photovoltaic power generation control method for new energy commercial vehicles. For example, the power battery pack of a pure electric commercial vehicle is divided into two battery zones, A and B, each with a capacity of 200Ah, capable of supporting the vehicle's independent driving range of 80 kilometers. The photovoltaic power generation module has a peak power of 1kW and is connected to the two battery zones A and B through a bidirectional DC / DC converter. This converter is controlled by the vehicle control unit (VCU) and can realize bidirectional energy flow and instantaneous parallel output.

[0031] Therefore, the specific steps of the aforementioned photovoltaic power generation control method for new energy commercial vehicles are as follows: Figure 1 As shown, it mainly includes:

[0032] Step S1: After the vehicle is powered on, determine the functions of the two pre-divided battery areas and perform photovoltaic charging on the battery area that is not the main power source.

[0033] After the vehicle is powered on and started, the VCU reads the status information of battery areas A and B reported by the BMS via the CAN bus. Assuming that battery area A has a charge of 90% (SOC_A=90%) and battery area B has a charge of 40% (SOC_B=40%), the VCU compares them and determines that battery area A, with the higher charge, will be the main power source. This activates the main relay, supplying power to all loads, including the vehicle's drive motor, air conditioning, and low-voltage electrical components. Simultaneously, the VCU sends a command to the DC / DC converter, instructing it to switch the output circuit of the photovoltaic power generation module to battery area B, initiating maximum power point tracking (MPPT) charging for battery area B.

[0034] Step S2: Start millisecond-level dynamic power difference monitoring, wherein the power difference is the real-time deviation between the real-time load power of the vehicle and the real-time power generation of the photovoltaic system, which is used to characterize the output pressure of the battery area responsible for the main power supply.

[0035] During the vehicle's operation with battery A as the primary power source and the photovoltaic module charging battery B, the VCU initiates a high-priority interrupt service routine to collect two key data streams in real time at 10ms intervals (milliseconds): one stream is the real-time vehicle load power P_load(t) from the drive motor controller and high-voltage load sensor, and the other stream is the real-time photovoltaic power generation P_pv(t) from the photovoltaic DC / DC converter. The VCU's internal logic calculates the dynamic power difference ΔP(t) in real time according to the following formula:

[0036] ΔP(t) = P_load(t) - P_pv(t)

[0037] The physical meaning of ΔP(t) is: the net load power that battery region A needs to independently bear at the current moment. The larger ΔP(t) is, the greater the output pressure of battery region A, and the smaller the buffer margin of the system to resist photovoltaic fluctuations or load changes.

[0038] Step S3: When it is determined that there is a risk of power surge based on the power difference, the dual-battery area collaborative buffer mode is triggered to temporarily smooth out and absorb the power surge.

[0039] In actual operation, the VCU has a preset power surge threshold ΔP_threshold, which is usually set to 30% of the maximum continuous discharge power of a single battery area (for example, if the maximum continuous discharge power of a single battery area is 100kW, then ΔP_threshold=30kW).

[0040] When the aforementioned steps detect that ΔP(t) > ΔP_threshold and the duration exceeds 20ms, the VCU determines that the system is about to or has already suffered a large power surge.

[0041] For example, if a vehicle suddenly accelerates to overtake another vehicle, P_load(t) increases instantaneously; or if a vehicle exits a tunnel, P_pv(t) jumps instantaneously. Both of these situations will cause a drastic change in the absolute value of ΔP(t), impacting the main battery region A.

[0042] At this moment, the VCU executes innovative control logic: forcing entry into a dual-zone collaborative buffer mode. In this mode, the VCU's original switching logic based on power supply is temporarily frozen. The VCU immediately sends a command to the DC / DC converter, instantly switching it from a unidirectional photovoltaic charging mode for battery zone B to a parallel connection mode between battery zone B and the DC / DC output. This means that battery zones A and B achieve physical parallel output at this instant through the bypass or bidirectional path of the DC / DC converter, with both battery zones jointly providing energy for the sudden increase in power demand ΔP(t).

[0043] This parallel output state is not permanent and can be controlled by a timer inside the VCU. For example, the duration t_duration can be set to 300ms (which can be calibrated within the range of 200-500ms). After 300ms, the VCU re-evaluates the system state: if ΔP(t) has fallen below the threshold, the system smoothly exits the cooperative buffer mode and the DC / DC converter resumes charging the B battery area; if ΔP(t) is still high, the system maintains the parallel state until it falls back.

[0044] The key function of this mechanism is that it does not abruptly switch between the two battery areas, but instead uses the B battery area as an "instantaneous buffer" to smoothly absorb power surges in a soft parallel manner. This completely avoids the voltage drop and current surge during switching in existing technologies, ensuring smooth driving.

[0045] Step S4: Based on the photovoltaic fluctuation trend, adaptively adjust the discharge cutoff threshold of the battery area as the main power source and the replenishment completion threshold of the battery area as the photovoltaic power source.

[0046] In order to fundamentally reduce the frequency of entering the above-mentioned collaborative buffering mode and optimize energy utilization efficiency, the present invention also proposes to introduce a threshold self-learning mechanism in some preferred embodiments, with the aim of dynamically adjusting the threshold.

[0047] For example, the VCU can, but is not limited to, maintain a rolling data window of 24 hours, recording the variance σ²(ΔP) of ΔP(t) within every 5-minute interval. A large variance indicates drastic fluctuations in solar power, like a vehicle traveling in cloudy conditions or frequently through tree-lined roads; a small variance indicates stable sunlight, like a vehicle driving on a sunny highway.

[0048] Therefore, the VCU can execute a dynamic threshold adjustment strategy, as shown below:

[0049] During periods of fluctuation (σ²(ΔP) > setpoint): To reserve more margin for battery area A to cope with unknown fluctuations, the VCU dynamically increases the discharge cutoff threshold of battery area A, for example, from the original setting of SOC_A_low=20%, to 25%-30% (the specific value can be determined by linear interpolation based on the variance). At the same time, the charging completion threshold of battery area B, for example, from the original setting of SOC_B_high=90%, is dynamically decreased to 80%-85%. This means that in a photovoltaic fluctuation environment, the system will not push battery area A to its limit, nor will it demand that battery area B be charged to near full capacity. Instead, it will perform master-slave switching earlier, allowing battery area B (e.g., 85% charge) to take over the work of battery area A (30% remaining charge), thereby ensuring that the main battery area always has sufficient power margin.

[0050] During stable periods (σ²(ΔP)≤set value): the VCU reverts to the original thresholds (20% and 90%) that are most economically optimal, maximizing the utilization of photovoltaic energy and reducing the cycle depth of the power battery.

[0051] Step S5: Dynamically monitor the actual power levels of the two battery zones, and perform a master-slave power supply switching action based on the power surge risk and the adjusted battery zone threshold.

[0052] Based on the dynamic monitoring and risk mitigation measures and battery zone threshold adjustments mentioned earlier, the VCU continuously monitors the charge levels of battery zones A and B. Assuming a stable period, after the aforementioned thresholds adaptively recover to 20% and 90%, when the charge level SOC_A of battery zone A drops to 20%, the VCU checks the charge level SOC_B of battery zone B: if SOC_B has reached 90% through photovoltaic power replenishment, the VCU determines that the switching conditions are met.

[0053] At this point, if ΔP(t) does not exceed the impact threshold, a smooth switch is performed: First, the DC / DC converter is switched from charging the B battery area to the A battery area; then, the main relay of the A battery area is disconnected, while the main relay of the B battery area is closed. After the switch is completed, the vehicle is driven by the B battery area, and the photovoltaic power generation module begins to charge the A battery area, which has run out of power.

[0054] Then, as the vehicle continues to drive, the above steps are repeated to achieve a dynamic and smooth alternation between the two battery areas in terms of discharging power and photovoltaic charging.

[0055] To elaborate further, in special operating conditions such as continuous rainy days, the photovoltaic power generation is at an extremely low level. Battery A discharges to the dynamically adjusted discharge cutoff threshold (e.g., 30%), while battery B's charge only slowly rises to 40%, far from reaching the charging completion threshold (e.g., 85%). In this situation, the VCU determines that it cannot perform a normal master-slave battery area function switch and enters emergency mode: it re-compares the current charge levels of battery A (30%) and battery B (40%), selecting battery B with the relatively higher charge level as the main power source, and switching battery B to continue supplying power to the vehicle. Simultaneously, components such as the instrument panel may, but are not limited to, illuminate a low-battery warning light and output a message to the driver: "Battery power is low, please charge promptly." In this mode, the photovoltaic power generation module continues to charge battery A until the vehicle is connected to an external charging station or the trip ends.

[0056] In summary, this invention constructs a complete closed-loop control strategy, from instantaneous response to trend adaptation, by introducing a collaborative buffering mechanism based on dynamic power difference monitoring and an adaptive threshold adjustment mechanism based on fluctuation trends. Compared with existing technologies, this invention is the first to achieve flexible buffering of photovoltaic fluctuations and load impacts in the field of commercial vehicle photovoltaic control, significantly improving the robustness and energy utilization efficiency of the system. This is an innovative concept that is difficult for those skilled in the art to directly derive from existing technologies.

[0057] In this invention, when directional terms are mentioned, they are relative concepts based on the embodiments. Furthermore, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0058] The above description of the structure, features, and effects of the present invention is based on the embodiments shown in the figures. However, the above are only preferred embodiments of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched by those skilled in the art to form a variety of equivalent solutions without departing from or changing the design concept and technical effects of the present invention. Therefore, the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A method for controlling photovoltaic power generation in new energy commercial vehicles, characterized in that, include: The vehicle's power battery is divided into a first battery area and a second battery area. Both the first battery area and the second battery area are configured to have the ability to independently drive the vehicle to work normally. Obtain the first charge level of the first battery region and the second charge level of the second battery region; When the first battery charge is greater than the second battery charge, the first battery area is controlled to discharge and supply power to the whole vehicle, and the photovoltaic power generation module is controlled to charge the second battery area. The discharge power of the first battery area and the charging power of the photovoltaic power generation module are monitored in real time, and the dynamic power difference ΔP is calculated. Based on the real-time changing trend of the dynamic power difference ΔP, the preset discharge cutoff threshold and energy replenishment completion threshold are dynamically adjusted. During the process of the first battery area discharging and supplying energy to the whole vehicle, the first battery charge and the second battery charge are monitored in real time; When the first battery level drops to the discharge cutoff threshold and the second battery level rises to the recharge completion threshold, the system switches to allow the second battery area to discharge and power the vehicle, and controls the photovoltaic power generation module to charge the first battery area.

2. The photovoltaic power generation control method for new energy commercial vehicles according to claim 1, characterized in that, The real-time monitoring of the discharge power of the first battery area and the charging power of the photovoltaic power generation module, and the calculation of the dynamic power difference ΔP, specifically includes: The dynamic power difference ΔP(t) is calculated using the following formula: ΔP(t) = P_load(t) - P_pv(t), where P_load(t) is the real-time load power of the vehicle and P_pv(t) is the real-time power generation of the photovoltaic module.

3. The photovoltaic power generation control method for new energy commercial vehicles according to claim 2, characterized in that, The control method further includes: When the dynamic power difference ΔP(t) is detected to exceed the preset power impact threshold, the role switching between the first battery area and the second battery area is temporarily frozen under the preset duration parameter, and the first battery area and the second battery area are controlled to output in parallel instantaneously to jointly power the vehicle load.

4. The photovoltaic power generation control method for new energy commercial vehicles according to claim 1, characterized in that, The step of dynamically adjusting the preset discharge cutoff threshold and recharging completion threshold based on the real-time changing trend of the dynamic power difference ΔP includes: Record and analyze the change curve of the dynamic power difference ΔP within a preset historical time period to identify the fluctuating and stable periods of photovoltaic power generation; During the fluctuating period, the discharge cutoff threshold is adjusted upward from the first preset value, and the recharging completion threshold is adjusted downward from the second preset value; during the stable period, the discharge cutoff threshold is restored to the first preset value, and the recharging completion threshold is restored to the second preset value.

5. The photovoltaic power generation control method for new energy commercial vehicles according to claim 4, characterized in that, The first preset value of the discharge cutoff threshold is 15%-20% of the total power, and the adjusted range is 25%-30%; the second preset value of the recharge completion threshold is 85%-90% of the total power, and the adjusted range is 75%-80%.

6. The photovoltaic power generation control method for new energy commercial vehicles according to claim 2 or 3, characterized in that, After the control switch is initiated by the second battery area discharging power to the vehicle, it also includes: When the dynamic power difference between the discharge power of the second battery area and the charging power of the photovoltaic power generation module for the first battery area is detected to exceed the power surge threshold again, the steps of pausing switching and parallel output are repeated.

Images