A BMS-based intelligent charging and discharging management system for a motor home battery

Abstract

The application discloses a kind of based on BMS's motor home battery intelligent charge-discharge management system, it is related to motor home energy management and battery management technical field, including multi-source energy input interface, attitude sensing module and BMS master module, attitude sensing module gathers the attitude data of motor home body, and the working condition identification unit in BMS master module identifies current working condition according to attitude data, and working condition identification result is synchronously output to multi-energy scheduling unit and equalization control unit, multi-energy scheduling unit combines working condition and electrical parameter to calculate the power distribution proportion of each energy, equalization control unit utilizes body posture change to assist to execute battery equalization, and when battery pack voltage inconsistency is out of limit, equalization demand signal is sent to multi-energy scheduling unit to adjust charging current weight.The application includes body posture information into energy scheduling decision, realizes the collaborative control of multi-energy scheduling and battery equalization, and improves the rationality and equalization efficiency of motor home battery management.

Description

Technical Field

[0001] This invention relates to the field of RV energy management and battery management technology, specifically to an intelligent charging and discharging management system for RV batteries based on a BMS. Background Technology

[0002] As a mobile living space, RVs typically require multiple energy sources for their power supply system, including external mains power, onboard fuel generators, solar photovoltaic panels, and vehicle-mounted generators. How to rationally allocate these energy sources under different usage scenarios and effectively manage the battery pack during charging and discharging is an important research direction in the field of RV energy management.

[0003] In the prior art, the invention patent with publication number CN122232443A discloses a multi-source coordinated charging and discharging control system for RVs. This system collects operating parameters from multiple power modules, constructs a three-dimensional objective function of power priority, load demand, and optimal energy consumption, combines this with neural network for operating condition identification, and employs reinforcement learning algorithms to optimize the charging and discharging power allocation ratio. The invention patent with publication number CN118514540B discloses an integrated RV power control system and RV, which uses a main controller to control the AC charging circuit and photovoltaic charging circuit based on battery remaining capacity, AC mains power input, and photovoltaic system input.

[0004] However, the aforementioned existing technologies all have the following shortcomings: First, the input parameters for multi-energy dispatching decisions are limited to electrical parameters, such as voltage, current, battery state of charge, and photovoltaic power, without taking into account changes in the vehicle's posture during driving or parking, such as tilting, swaying, and bumping. Second, battery balancing strategies still rely on conventional balancing circuits and do not utilize the vehicle's motion state to assist in balancing. Existing technologies treat energy dispatching and battery balancing as independent functional modules, lacking information sharing and coordinated control between the two.

[0005] In summary, existing RV charging and discharging management systems neglect vehicle motion attitude information in multi-energy scheduling decisions and fail to coordinate energy scheduling with battery balancing. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a BMS-based intelligent charging and discharging management system for RV batteries. By introducing an attitude perception module to collect attitude data such as roll angle, pitch angle, yaw rate of change, and three-axis vibration acceleration of the RV body, the multi-energy scheduling unit can dynamically adjust the power distribution ratio of each energy source according to the current operating conditions. At the same time, the equalization control unit can use the changes in vehicle attitude to assist in performing battery equalization. By synchronously outputting the operating condition identification results to the scheduling unit and the equalization control unit, the two can cooperate to solve the above-mentioned problems.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a smart charging and discharging management system for RV batteries based on a BMS, the system comprising: A multi-source energy input interface is connected to a DC bus via a power conversion unit, and the DC bus is connected to a battery pack via a bidirectional DC / DC converter. The attitude perception module is used to collect attitude data of the RV body, including roll angle, pitch angle, yaw rate of change and three-axis vibration acceleration. The BMS main control module includes an operating condition identification unit, a multi-energy scheduling unit, and a balance control unit; The operating condition identification unit is used to identify the current operating condition of the RV based on attitude data; The multi-energy dispatching unit is used to calculate the power allocation ratio of each energy source based on the current operating conditions and the electrical parameters of the multi-source energy input interface, and output dispatching instructions to each power conversion unit. The equalization control unit is used to control the equalization actuator to perform sway-assisted equalization based on attitude data and battery cell voltage data when the current operating condition is driving or parking swaying. The BMS main control module is also used to synchronously output the current operating condition identified by the operating condition identification unit to the multi-energy scheduling unit and the equalization control unit. When the equalization control unit detects that the voltage inconsistency of the battery pack exceeds a preset threshold, it sends an equalization demand signal to the multi-energy scheduling unit. The multi-energy scheduling unit adds a charging current weight to the calculation of the power allocation ratio based on the equalization demand signal. The operating condition identification unit provides the same operating condition identification result to both the multi-energy scheduling unit and the balance control unit, enabling scheduling decisions and balance execution to work collaboratively based on the same motion state cognition.

[0008] Furthermore, when calculating the power allocation ratio of each energy source, the multi-energy scheduling unit constructs a four-dimensional objective function: Where F1 is the power priority score, F2 is the load demand matching score, F3 is the energy consumption economy score, F4 is the motion posture adaptability score, and , , , are weight coefficients, which represent the weight values ​​of F1, F2, F3, and F4 in the four-dimensional objective function, respectively. Each weight coefficient is a real number between 0 and 1, and +++=1. The motion posture adaptation score F4 is determined based on the current operating conditions: under driving conditions, the adaptation score of the vehicle generator is higher than that of the photovoltaic and mains power; under parking level conditions, the adaptation scores of mains power and photovoltaic are higher than that of the vehicle generator; under parking tilt conditions, the adaptation score of the fuel generator increases according to the balanced demand signal. The multi-energy scheduling unit calculates the globally optimal power allocation ratio in each scheduling cycle through a four-dimensional objective function, so that the scheduling scheme of each energy source matches the current motion state of the RV.

[0009] Furthermore, the weighting coefficients are dynamically adjusted according to the user's preset mode, which includes economic mode, comfort mode and environmental protection mode; In the economic mode, the value of is greater than the value of , and in the environmental mode, the power priority score F1 of photovoltaic is higher than the power priority score F1 of fuel generator.

[0010] Furthermore, the attitude perception module includes multiple MEMS inertial measurement units and multiple tilt sensors, which are distributed at the front, rear, sides, and inside the battery compartment of the RV. The sampling frequency of the attitude perception module is not less than 100Hz. The tilt sensors inside the battery compartment independently collect the actual tilt angle experienced by the battery pack, eliminating the deviation between the vehicle attitude and the battery pack attitude caused by the RV suspension system.

[0011] Furthermore, the current operating conditions identified by the operating condition identification unit include driving on a flat road, driving uphill, driving downhill, driving while turning, parking at a level position, parking at an angle, and parking swaying. The conditions for identifying the driving and climbing conditions are that the pitch angle is greater than 5 and the vehicle is in a driving state; The conditions for identifying the downhill driving condition are that the pitch angle is < -5 and the vehicle is in motion; The identification condition for the parking tilt condition is that the vehicle is in a parking state and the roll angle or pitch angle is 3. The identification condition for the parking sway condition is that the vehicle is in a parking state and the rate of change of the roll angle is 5 / s. The working condition identification unit performs sliding window statistical processing on continuous attitude data to eliminate attitude misjudgment caused by instantaneous bumps.

[0012] Furthermore, the battery pack includes multiple battery modules, and each battery module includes multiple battery cells and an equalization actuator; The equalization actuator includes a conventional equalization circuit and a swing-assisted equalization device. The conventional equalization circuit includes a passive equalization resistor array and an active equalization converter. The swing-assisted equalization device includes an elastic support mechanism, a guide mechanism, and a controllable switch array disposed on the mounting base of each battery module. The elastic support mechanism is used to displace the battery module along the tilt direction when the RV body is tilted, and the controllable switch array is used to electrically connect the high-potential battery cell and the low-potential battery cell in the tilt direction according to the instructions of the equalization control unit. When the vehicle body tilts, the elastic support mechanism causes the cells in the battery module to shift in spatial position, creating an open-circuit voltage difference between the high-potential cells and the low-potential cells caused by gravity.

[0013] Furthermore, when the current operating condition is a parking level condition and the battery pack voltage inconsistency exceeds a preset threshold, the equalization control unit controls the conventional equalization circuit to perform equalization. When the current operating condition is driving or parking swaying, the equalization control unit controls the swaying auxiliary equalization device to perform equalization. When the current operating condition is a parking tilt condition, the equalization control unit selects to control the conventional equalization circuit or the swing-assisted equalization device to perform equalization based on the magnitude of the battery pack voltage inconsistency. When the voltage inconsistency of the battery pack is greater than 100mV, the conventional equalization circuit is controlled to perform equalization. When the battery pack voltage inconsistency reaches 100mV and exceeds the preset threshold, the swing-assisted equalization device is controlled to perform equalization. The equalization control unit automatically matches the equalization mode according to the degree of voltage inconsistency when the vehicle is parked and tilted. When the voltage difference is large, conventional equalization is used for fast processing, and when the voltage difference is small, swing-assisted equalization is used to achieve low power consumption processing.

[0014] Furthermore, when the equalization control unit controls the swing-assisted equalization device to perform equalization, it calculates the current tilt direction and tilt angle based on the attitude data, determines the spatial position of the high-potential cell and the low-potential cell based on the battery cell voltage data, and controls the controllable switch array to conduct the circuit between the high-potential cell and the low-potential cell when the tilt direction is consistent with the direction where the high-potential cell is located. When the roll angle or pitch angle changes periodically, the equalization control unit controls the controllable switch array to turn on and off synchronously according to the frequency of the periodic change. The equalization control unit controls the controllable switch array to alternately turn on and off according to the rhythm of the swaying when the vehicle body sways periodically, so that the equalization action is synchronized with the swaying action.

[0015] Furthermore, the multi-source energy input interface includes an external AC power input interface, a vehicle-mounted fuel generator input interface, a solar photovoltaic panel input interface, and a vehicle generator input interface; The external AC power input interface is connected to the DC bus via an AC / DC converter. The on-board fuel generator input interface is connected to the DC bus via a rectifier unit and a DC-DC converter. The solar photovoltaic panel input interface is connected to the DC bus via an MPPT unit and a DC-DC converter. The vehicle generator input interface is connected to the DC bus via a DC-DC converter.

[0016] Furthermore, the multi-energy scheduling unit calculates the power allocation ratio at a 5-minute interval and immediately recalculates the power allocation ratio when the load management module detects a sudden change in load power. The power allocation ratio calculated by the multi-energy dispatching unit is the percentage of the output power of each energy source to the total load power, and the sum of the percentages is 100%. The immediate recalculation mechanism triggered by the multi-energy scheduling unit when the load power changes abruptly enables the system to re-optimize power allocation within 100ms when the load fluctuates.

[0017] Compared with existing technologies, this BMS-based intelligent charging and discharging management system for RV batteries has the following advantages: I. This invention incorporates attitude data such as roll angle, pitch angle, yaw rate of change, and vibration acceleration of the RV body into the multi-energy scheduling and battery balancing decision-making process by setting up an attitude perception module and a working condition recognition unit. The recognized working conditions are then synchronously output to the multi-energy scheduling unit and the balancing control unit, enabling power distribution to actively match the actual motion states of the vehicle, such as driving, parking, tilting, or swaying. At the same time, the changes in vehicle body attitude are used to assist in battery cell balancing. This solves the problem in the prior art where energy scheduling and battery balancing are independent and ignore vehicle attitude information, thus improving the rationality of matching energy supply with load demand.

[0018] II. This invention constructs a swing-assisted balancing device by setting an elastic support mechanism and a controllable switch array on the battery module mounting base. Under the swinging conditions of driving or parking, the relative position of the battery cells caused by the vehicle body tilt and swing is used to achieve gravity-assisted charge redistribution. The balancing process does not require additional battery energy to drive the high-power balancing circuit, which can reduce balancing power consumption and balancing device heat generation, extend the service life of the balancing actuator, and improve the reliability and response speed of battery balancing under long-term operation.

[0019] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0021] Figure 1 This is a block diagram of the overall system architecture of the present invention; Figure 2 This is a flowchart of the working condition identification process of the present invention. Detailed Implementation

[0022] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0023] This embodiment provides a BMS-based intelligent charging and discharging management system for RV batteries. This system deeply integrates vehicle attitude perception with multi-energy scheduling and battery balancing, solving the problems of unreasonable energy distribution and limited balancing efficiency caused by neglecting vehicle motion status in existing technologies.

[0024] The overall system architecture is as follows Figure 1 As shown, the system includes a multi-source energy input interface, a power conversion unit, a DC bus, a bidirectional DC / DC converter, a battery pack, an attitude sensing module, and a BMS main control module. The BMS main control module integrates a working condition identification unit, a multi-energy scheduling unit, and a balance control unit. The specific implementation methods of each part are explained in detail below.

[0025] The multi-source energy input interface includes an external AC power input interface, an on-board fuel generator input interface, a solar photovoltaic panel input interface, and a vehicle alternator input interface. The external AC power input interface connects to the DC bus via an AC / DC converter, converting 220V AC AC power to 48V DC power. The AC power output from the on-board fuel generator input interface is first rectified to DC by a rectifier unit, and then connected to the DC bus via a DC-DC converter, stabilizing the voltage at 48V. The solar photovoltaic panel input interface connects to the DC bus via an MPPT unit and a DC-DC converter. The MPPT unit tracks the photovoltaic maximum power point in real time, and the DC-DC converter converts the fluctuating photovoltaic voltage to a stable 48V. The vehicle alternator input interface connects directly to the DC bus via a DC-DC converter, boosting the 14V or 28V DC power output from the vehicle alternator to 48V. The DC bus voltage is designed to be 48V and connects to the battery pack via a bidirectional DC / DC converter. The battery pack, with a rated voltage of 48V, consists of multiple lithium iron phosphate battery modules connected in series. A bidirectional DC / DC converter can both charge the battery pack and feed battery energy back to the DC bus to supply the load.

[0026] The attitude sensing module collects attitude data of the RV body, including roll angle, pitch angle, yaw rate of change, and X-axis, Y-axis, and Z-axis vibration acceleration. The attitude sensing module comprises multiple microelectromechanical inertial measurement units (MEMS) and multiple tilt sensors, with their placement specifically designed. The first inertial measurement unit is installed near the front axle at the front of the RV; the second inertial measurement unit is installed inside the rear bumper; the third and fourth inertial measurement units are installed at the bottom of the left and right B-pillars, respectively; and a dual-axis tilt sensor is independently mounted on the battery pack mounting base inside the battery compartment. Each inertial measurement unit integrates a three-axis accelerometer and a three-axis gyroscope, with an accelerometer range of 16g ​​and a gyroscope range of 2000 / s, capable of fully capturing bumps, turns, acceleration / deceleration, and swaying during parking. The tilt sensors use a MEMS tilt measurement chip with a resolution of 0.01 for accurate static angle measurement. All sensors transmit data to the BMS main control module via the CAN bus at a sampling frequency of 100Hz. Specifically, the tilt sensor inside the battery compartment separately collects the actual tilt angle experienced by the battery pack. This data is used to eliminate the deviation between the vehicle's attitude caused by the RV's suspension system and the battery pack's true attitude. For example, when the RV is parked on a slope, the vehicle's pitch angle is 7°, but due to the battery compartment's installation position and suspension deformation, the actual tilt angle might be 6.5°. The BMS main control module prioritizes the data from the tilt sensor inside the battery compartment as the battery pack's true attitude angle, while the vehicle's attitude angle is used for operational condition identification.

[0027] The BMS main control module is based on an automotive-grade microcontroller, running a real-time operating system. Its internal software is divided into a working condition identification unit, a multi-energy scheduling unit, and a balance control unit. These three units exchange data via shared memory to ensure timely and consistent information transmission.

[0028] The driving condition identification unit is responsible for identifying the current driving condition of the RV based on attitude data. There are seven types of driving conditions identified: driving on a flat road, driving uphill, driving downhill, driving while turning, parking at a level position, parking with an incline, and parking with a sway. The determination of whether the vehicle is in a driving or parking state is based on the vehicle speed and gear signals from the CAN bus. When the vehicle speed is consistently >1 km / h and the gear is in driving gear, it is determined to be in a driving state; when the vehicle speed is 0 and the handbrake is engaged or the vehicle is in parking gear, it is determined to be in a parking state. The driving condition identification unit performs sliding window statistical processing on continuous attitude data, with a window duration of 2 seconds and a sliding window step of 0.1 seconds, to eliminate attitude misjudgments caused by momentary bumps or single vibrations. The specific identification conditions for each driving condition are as follows: Driving on flat roads: The vehicle is in motion, and the average absolute value of the pitch angle within the window is <3, the average absolute value of the roll angle is <3, and the average rate of change of the yaw angle is <10 / s.

[0029] Driving and climbing conditions: The vehicle is in motion and the average pitch angle within the window is greater than 5.

[0030] Driving downhill condition: The vehicle is in motion and the average pitch angle within the window is < -5.

[0031] Driving and turning conditions: The vehicle is in motion and the average rate of change of yaw angle within the window is >15 / s.

[0032] Parking level condition: The vehicle is parked, and the absolute value of the average roll angle within the window is <3, and the absolute value of the average pitch angle is <3.

[0033] Parking tilt condition: The vehicle is in a parked state, and the average absolute value of the roll angle or the average absolute value of the pitch angle within the window is 3.

[0034] Parking sway condition: The vehicle is parked, and the average rate of change of roll angle within the window is >5 / s, or the average rate of change of pitch angle is >5 / s. Here, the rate of change of roll angle is directly output by the inertial measurement unit, avoiding noise introduced by differential calculation.

[0035] like Figure 2As shown in the figure, the logical process from raw attitude data input, sliding window filtering, feature extraction to operating condition determination is illustrated. The attitude data is first low-pass filtered to remove high-frequency glitches, then enters the sliding window buffer, where the mean, root mean square, and mean rate of change of each angle within the window are calculated. The operating condition identification unit outputs the current operating condition label every 100ms, along with confidence information. Only when 10 consecutive identification results are consistent is the operating condition label locked and transmitted to the multi-energy scheduling unit and the equalization control unit to prevent frequent switching in the operating condition transition zone.

[0036] The multi-energy dispatch unit calculates the power allocation ratio of each energy source based on the current operating conditions and the electrical parameters of the multi-source energy input interfaces, and outputs dispatch commands to each power conversion unit. The electrical parameters include the input voltage, input current, available power limit, mains power connection status, fuel generator start / stop status, photovoltaic maximum power point, and power related to the speed of the vehicle generator. The multi-energy dispatch unit constructs a four-dimensional objective function to comprehensively evaluate the advantages and disadvantages of each power allocation scheme. The objective function is in the form of: Where F1 is the power priority score, F2 is the load demand matching score, F3 is the energy consumption economy score, and F4 is the motion attitude adaptability score. , , , and are weighting coefficients, all real numbers between 0 and 1, and +++=1. Within each scheduling cycle, the multi-energy scheduling unit enumerates all feasible power output combinations, calculates the F value for each combination, and selects the combination with the largest F value as the power allocation scheme for this cycle.

[0037] The power priority score F1 reflects the preset usage order of each power source. The system has a pre-set priority table. Under normal conditions, photovoltaic (PV) power has the highest priority, followed by external grid power, then the vehicle generator, and finally the vehicle-mounted fuel generator. F1 is calculated as follows: for a given power source combination, the score of each power source equals its priority coefficient multiplied by the proportion of its actual output to its available power, and then these coefficients are summed. The priority coefficients are 1.0 for PV, 0.8 for grid power, 0.6 for the vehicle generator, and 0.4 for the fuel generator. This tends to prioritize the use of PV and grid power.

[0038] The load demand matching score F2 indicates the degree of matching between the total power supply output and the current total load power. The load power on the DC bus is collected, and the absolute value of the difference between the total power supply output and the load power is calculated. The matching score F2 = 1 minus the ratio of this difference to the load power. F2 is 1 when the total output is exactly equal to the load power.

[0039] The energy efficiency score F3 is calculated based on the unit energy cost of each energy source. The cost of photovoltaic power generation is pre-set to be approximately 0, the cost of grid electricity is 0.8 yuan per kWh, the cost of a vehicle generator (utilizing engine surplus power) is 0.5 yuan per kWh, and the cost of a fuel generator is 2.5 yuan per kWh. For a given combination, the weighted average cost is calculated, and the energy efficiency score F3 = 1 minus the normalized cost value; the lower the cost, the higher the score.

[0040] The motion posture adaptation score F4 is the core innovation dimension of this invention. This score dynamically determines the adaptation coefficient of each power source based on the current working condition output by the working condition identification unit, and then weights and sums the adaptation coefficients with the output ratio of that power source. The rules for determining the adaptation coefficients are as follows: When driving on flat roads or climbing / descending slopes, the adaptation coefficient of the vehicle generator is set to 0.9, the fuel generator 0.5, the photovoltaic 0.4, and the mains power 0.1, because the vehicle generator can stably provide power while the vehicle is in motion, and connecting to the mains power is not practical at this time. When driving and turning, the adaptation coefficient of the vehicle generator is 0.8, and the coefficients of other power sources are appropriately lowered to avoid sudden changes in generator load affecting handling when turning. When parking at a level position, the adaptation coefficients of the mains power are 0.95, the photovoltaic 0.9, the vehicle generator 0.1, and the fuel generator 0.3, with priority given to using campsite mains power and photovoltaic power. When parking at an angle, the adaptation coefficient of the fuel generator will be dynamically adjusted according to the balance demand signal. The specific adjustment mechanism is as follows: When the equalization control unit detects that the battery pack voltage inconsistency exceeds a preset threshold and sends an equalization demand signal to the multi-energy dispatching unit, the multi-energy dispatching unit increases the fuel generator adaptability coefficient from the baseline value of 0.3 to 0.7, thereby increasing the probability of the fuel generator being activated and increasing the charging current to meet the additional energy required for equalization. Under parking swaying conditions, due to frequent vehicle body shaking, connecting to mains power poses a safety hazard, so the mains power adaptability coefficient automatically drops to 0. If solar power is available, the adaptability coefficient is 0.8, and the fuel generator adaptability coefficient is 0.4.

[0041] The weighting coefficients are dynamically adjusted based on the preset modes selected by the user via the central control screen. These preset modes include Economy Mode, Comfort Mode, and Eco Mode. In Economy Mode, the values ​​are 0.5, 0.2, 0.15, and 0.15, emphasizing economy. In Comfort Mode, the values ​​are 0.4, 0.2, 0.2, and 0.2, prioritizing load matching and preventing power fluctuations from affecting electrical equipment. In Eco Mode, the value is 0.4, the priority coefficient for photovoltaic power is further increased to 1.2, and the priority coefficient for fuel generators is reduced to 0.2, with values ​​of 0.2, 0.2, and 0.2 respectively. Users can switch modes at any time while driving or parked, and the multi-energy dispatching unit will execute according to the new weights in the next dispatching cycle.

[0042] The multi-energy dispatch unit calculates the power allocation ratio using a basic dispatch cycle of 5 minutes. The calculated power allocation ratio is the percentage of each energy source's output power to the total load power, with the sum of these percentages equal to 100%. When the load management module detects a sudden change in load power exceeding 200W, it triggers an immediate recalculation mechanism. Within 100ms, the multi-energy dispatch unit re-optimizes the power allocation and updates the output reference values ​​of each converter. For example, when a high-power air conditioner is turned on, causing the load to suddenly increase from 800W to 2200W, the dispatch unit reallocates power output within 100ms, prioritizing the response of photovoltaic and vehicle generators, with the battery supplementing any shortfall to ensure the bus voltage does not drop.

[0043] The BMS main control module synchronously outputs the current operating condition identified by the operating condition identification unit to the multi-energy scheduling unit and the equalization control unit. The operating condition tags received by both units are always consistent. The operating condition identification unit updates the operating condition every 100ms and pushes it to both units simultaneously through a message queue, ensuring that scheduling decisions and equalization execution are based on the same motion state perception, thereby achieving information sharing and collaborative control.

[0044] The battery pack consists of four battery modules connected in series. Each module has a rated voltage of 12.8V and contains four lithium iron phosphate cells connected in series. It is equipped with a battery monitoring unit to collect the voltage and temperature of each cell in real time. The balancing mechanism comprises a conventional balancing circuit and a swing-assisted balancing device. The battery modules are mounted on a metal base plate, which is connected to the RV's battery compartment frame via an elastic support mechanism. This elastic support mechanism consists of four sets of cylindrical helical springs and linear guides, with a spring stiffness coefficient of 15N / mm, allowing the battery modules to move a maximum of 8mm horizontally and vertically within the base plate plane. The guiding mechanism uses cross roller guides to restrict the battery modules to translational movement only in the horizontal plane without torsion. The controllable switch array consists of 16 N-channel MOSFETs. The positive and negative terminals of each cell are selectively connected to two lines of the balancing bus via switches. A current-limiting resistor is connected in series on the balancing bus.

[0045] A conventional equalization circuit includes a passive equalization resistor array and an active equalization converter. The passive equalization resistors connect a 33Ω resistor and a switching transistor in parallel with each cell for low-current discharge equalization. The active equalization converter uses a bidirectional flyback converter topology, capable of transferring energy between any two cells, with a maximum equalization current of 2A. The conventional equalization circuit is directly controlled by the equalization control unit and can independently perform voltage equalization of the battery pack.

[0046] The swing-assisted balancing device works as follows: When the RV body tilts, the elastic support mechanism undergoes compression deformation due to the gravitational component, causing the battery module to slide slightly along the guide rail in the tilt direction. This displacement changes the relative position of each cell in space. For example, if the vehicle body tilts to the left with a positive roll angle, the battery module shifts to the left, lowering the relative position of the cells on the left and raising the relative position of the cells on the right. The balancing control unit obtains the real-time voltage of each cell through the battery monitoring unit to determine the numbers of the cells with the highest and lowest potentials. Combined with the tilt direction provided by the attitude sensing module, it determines whether the high-potential cell is in a low or high tilt position. When the tilt direction is consistent with the direction of the high-potential cell, i.e., the high-potential cell is exactly in a low tilt position, the controllable switch array is controlled to connect the high-potential cell and the low-potential cell through the balancing bus and the current-limiting resistor, using the voltage difference between them for passive discharge balancing. This method of passively positioning high and low potential cells by means of changes in vehicle body posture replaces the complex selection logic in traditional equalization circuits. It also utilizes the slight stratification effect of the electrolyte inside the cell under the action of gravity to slightly increase the voltage difference and increase the equalization driving force.

[0047] The equalization control unit has a complete equalization mode decision logic that automatically selects the equalization method based on the current operating conditions and battery pack voltage inconsistencies. Voltage inconsistency is defined as the difference between the highest and lowest voltage cells in the battery pack. The preset threshold is set to 30mV.

[0048] When the current operating condition is a parked level condition and the voltage inconsistency exceeds 30mV, the equalization control unit controls the conventional equalization circuit to perform equalization. At this time, if the inconsistency is >100mV, the active equalization converter is activated for rapid energy transfer; if the inconsistency is between 30mV and 100mV, the passive equalization resistor is activated for fine adjustment.

[0049] When the current operating condition is driving or parking swaying, the equalization control unit prioritizes controlling the swaying auxiliary equalization device to perform equalization. During this time, the vehicle body continuously bumps or sways, the elastic support mechanism moves back and forth, and the battery modules continuously shift back and forth. The equalization control unit utilizes this motion condition to control the controllable switch array to synchronously turn on and off according to the periodic changes in attitude data. For example, in parking swaying, the roll angle oscillates between +6 and -6 at a frequency of approximately 0.4Hz. The equalization control unit extracts the moment the roll angle crosses zero, and during the half-cycle of the roll angle changing from positive to negative, it connects the high-potential cell on the left to the low-potential cell on the right, and in the reverse half-cycle, it connects the high-potential cell on the right to the low-potential cell on the left. This results in an alternating current for equalization, with cells charging and discharging alternately, achieving an overall redistribution of charge, similar to the swaying effect. Simultaneously, because the equalization current is only conducted during a portion of the swaying cycle, the average power consumption is low, reducing heat generation on the equalization resistor.

[0050] When the vehicle is parked at an angle, the equalization control unit selects between the conventional equalization circuit and the swing-assisted equalization device to perform equalization based on the magnitude of the voltage inconsistency in the battery pack. When the voltage inconsistency is greater than 100mV, it is considered that the cell differences are significant and requires rapid intervention. In this case, the conventional equalization circuit is controlled, prioritizing the use of the active equalization converter. When the voltage inconsistency is between 100mV and 30mV, the swing-assisted equalization device is controlled to perform equalization, utilizing the low-power equalization advantage of the vehicle's tilted position for fine balancing. This adaptive matching mechanism employs high-speed equalization when the cell deviation is large and low-power swing-assisted equalization when the deviation is small, balancing equalization speed and energy efficiency.

[0051] When the equalization control unit detects that the battery pack voltage inconsistency exceeds a preset threshold of 30mV, it not only performs equalization but also sends an equalization demand signal to the multi-energy scheduling unit. This signal contains a suggested minimum equalization charging current value. Upon receiving the equalization demand signal, the multi-energy scheduling unit adds a charging current weight to the power allocation ratio calculation. Specifically, in the motion attitude adaptation score F4 of the four-dimensional objective function, an adaptation coefficient is temporarily added for power sources that can provide high-current charging. For example, in the parking tilt condition, the adaptation coefficient of the fuel generator is increased from the baseline value of 0.3 to 0.7, causing the overall power allocation to favor starting the fuel generator to provide additional charging power to the battery, ensuring sufficient energy support for the equalization process. At the same time, when calculating the power allocation scheme, the scheduling unit constrains the battery charging power to be no less than the minimum charging power required for equalization. When equalization is completed and the voltage inconsistency falls back below the threshold, the equalization demand signal is withdrawn, the adaptation coefficient is restored, and the multi-energy scheduling unit resumes scheduling according to the original objective function.

[0052] The following provides specific implementation data for three typical application scenarios to further illustrate the collaborative working process of the system: In Scenario 1, the implementation of coordinated charging, discharging, and balancing under hill-climbing conditions: The RV is driving on a continuous uphill mountain road with a gradient of approximately 8% and a speed of approximately 50 km / h. Real-time data collected by the attitude perception module includes: average pitch angle 8.2, average roll angle 2.1, average yaw rate of change 4 / s, root mean square (RMS) Z-axis vibration acceleration 1.8 m / s², and RMS X-axis vibration acceleration 0.9 m / s². The condition identification unit, after statistical analysis via a sliding window, determines the condition to be hill-climbing and outputs the corresponding label. At this time, the total load power is 2800W, mainly including 1200W for the air conditioner, 150W for the refrigerator, 200W for lighting and entertainment equipment, and 1250W for other components. The solar photovoltaic panels are blocked by the mountainside, with an output power of only 150W. The vehicle's generator currently has a maximum available power of 1600W, but the actual output is affected by engine speed and can stably provide 1500W. The onboard fuel generator is in standby mode, and external AC power is not connected. The battery pack SOC is 62%, and the battery pack voltage inconsistency is 55mV, exceeding the threshold. The equalization control unit sends an equalization demand signal, requesting at least 500W of charging power margin for equalization.

[0053] After receiving the driving hill-climbing condition and balancing demand signals, the multi-energy dispatching unit performs calculations in a 5-minute dispatching cycle. The weighting coefficients adopt the user's currently selected economic mode: =0.15, =0.2, =0.5, =0.15. The adaptability coefficients for each power source are set according to rules: 0.9 for the vehicle generator, 0.4 for photovoltaic, and the fuel generator is temporarily increased to 0.65 due to the received balancing demand signal. During the objective function calculation, several typical output combinations are enumerated. Combination 1: Vehicle generator 1500W, photovoltaic 150W, fuel generator 0W, total output 1650W. The 1150W shortfall is discharged by the battery, which cannot be charged. Combination 2: Vehicle generator 1500W, photovoltaic 150W, fuel generator 1300W, total output 2950W. After meeting the 2800W load, the remaining 150W is used for charging, with a charging power of 150W, leaving 500W for the balancing request. Combination 3: A 1600W full-power electric vehicle generator, a 150W photovoltaic power source, and a 1600W fuel generator, totaling 3350W output and 550W charging power. This combination meets the power balancing requirements, and the sum of the products of the output and adaptability coefficients of each power source is high. Combination 3 achieves a significantly higher F-score than the previous two, resulting in the highest F-value. The dispatch unit outputs the following dispatch instructions: the electric vehicle generator outputs 1600W, the fuel generator starts and outputs 1600W, the photovoltaic MPPT unit outputs 150W, the total DC bus input is 3350W, the load consumption is 2800W, and the bidirectional DC / DC converter charges the battery pack at 550W. In actual execution, the fuel generator takes approximately 2 seconds to stabilize from standby, during which the battery briefly supplements the lost power, and the load is unaffected.

[0054] During this hill-climbing driving condition, the equalization control unit activated the sway-assisted equalization device. The bumpy mountain road caused continuous movement of the elastic support mechanism, resulting in the battery modules reciprocating slightly on the guide rails. The highest voltage cell was the third one in module 2, with a voltage of 3.452V, while the lowest voltage cell was the first one in module 4, with a voltage of 3.397V, a difference of 55mV. Based on real-time changes in roll and pitch angles, the attitude sensing module continuously calculated the tilt direction. When the tilt direction caused the high-potential cell to be in a relatively low position, the equalization control unit drove the corresponding MOSFET switch to turn on, with a peak discharge current of 0.8A. The switch remained on for 50ms before turning off, waiting for the next in-phase sway to turn it on again. The entire hill-climbing process lasted 45 minutes, during which the battery pack's SOC charged from 62% to 78%, and the voltage inconsistency gradually decreased from 55mV to 9mV. The equalization process did not consume additional battery energy; all energy came from the charging margin provided by the vehicle's alternator and fuel generator. After the equalization process is completed, the equalization demand signal is automatically cleared. In the next cycle, the scheduling unit restores the fuel generator adaptability coefficient to 0.5, and the fuel generator then reduces its power or shuts down, and the system returns to the pure driving charging mode.

[0055] In Scenario 2, the implementation of sway-assisted balancing under parking sway conditions: The RV is parked in an open area by a lake and encounters a gust of wind, causing the vehicle to sway periodically from side to side. Attitude perception module data: roll angle change amplitude 7.5, change period 2.6s, average pitch angle 0.8, average yaw angle change rate 2 / s, and root mean square Y-axis vibration acceleration 0.6m / s². The condition identification unit determines it to be a parking sway condition. At this time, the total load power is 400W, mainly from the refrigerator and lighting. The photovoltaic panel receives good sunlight, and the MPPT output power is 580W. External AC power is not connected, the vehicle alternator is off, and the fuel generator is off. The battery pack SOC is 81%, and the voltage inconsistency is 38mV, exceeding the preset threshold. The balancing control unit sends a balancing demand signal, requesting a charging current of no less than 3A.

[0056] The multi-energy dispatch unit receives the parking swing condition tag and reads the balancing demand signal. Under this condition, the grid adaptability coefficient automatically drops to 0, and the photovoltaic adaptability coefficient is 0.8. Since the photovoltaic power is sufficient and the load is only 400W, the 580W photovoltaic output can provide 180W of charging power, corresponding to a charging current of 3.75A, meeting the balancing demand. The objective function calculation uses only photovoltaic power, with a 100% allocation ratio. The dispatch unit maintains the maximum MPPT output of 580W, with 180W for battery charging and 400W for the load.

[0057] Due to the vehicle's swaying condition, the equalization control unit activated the sway-assisted equalization device. The roll angle changed periodically at approximately 0.38Hz. The equalization control unit extracted the zero-crossing point of the roll angle signal. Within one sway cycle, the left high-potential cell was switched with the right low-potential cell via a switch array in the first half of the cycle, and the reverse direction was observed in the second half. The average equalization current was 0.5A, the peak instantaneous power consumption at the equalization current-limiting resistor was 1.2W, and the average power consumption was approximately 0.3W, indicating overall low-power operation. After 25 minutes, the battery pack voltage inconsistency decreased from 38mV to 5mV, demonstrating a significant equalization effect, with the battery temperature rising by only 1.5℃. After equalization was completed, the equalization demand signal was withdrawn, and the multi-energy dispatch unit continued to supply power via photovoltaics, with excess energy continuing to float charge the battery with a small current.

[0058] In Scenario 3, the implementation of adaptive balancing and energy dispatching under tilted parking conditions: The RV is parked at a slope campsite, with its front facing downhill. Attitude perception module data shows: average pitch angle -6.8, average roll angle 1.5, and very low three-axis vibration acceleration. The condition identification unit determines it to be a tilted parking condition. At this time, the total load power is 650W, but the photovoltaic power is only 180W due to tilt and partial shading. External AC power is not connected, and the vehicle's alternator is off. The battery pack SOC is 35%, requiring urgent charging. The battery pack voltage inconsistency is 135mV, exceeding 100mV. According to the balancing control unit's decision logic, a conventional balancing circuit should be used for rapid intervention. The balancing control unit then activates the active balancing converter and simultaneously sends a balancing demand signal to the multi-energy dispatching unit, recommending a charging power of no less than 800W.

[0059] Under parked tilt conditions, the multi-energy dispatch unit has a baseline adaptability coefficient of 0.95 for mains power, 0.9 for photovoltaic power, and 0.3 for the fuel generator. Upon receiving a balancing demand signal, the adaptability coefficient of the fuel generator is increased to 0.7. Calculations using the objective function show that the 180W output of the photovoltaic system is limited and cannot meet the charging requirements when used alone; however, starting the fuel generator can provide high-power charging. The final selected combination is: 2000W output from the fuel generator, 180W from the photovoltaic system, for a total input of 2180W, a load of 650W, and a charging power of 1530W, far exceeding the requested 800W. Upon receiving the dispatch command, the fuel generator starts and stabilizes, and the bidirectional DC / DC converter charges the battery pack with a high current of 1530W. The active balancing converter in the conventional balancing circuit draws energy from the highest voltage cell and transfers it to the lowest voltage cell, with a balancing current of 2A. After approximately 12 minutes, the battery pack's SOC rises to 48%, and the voltage inconsistency rapidly decreases from 135mV to 18mV, below the threshold of 30mV. The equalization control unit shuts down the active equalization circuit and cancels the equalization demand signal. The multi-energy dispatching unit detects the disappearance of the equalization demand signal in the next 5-minute dispatching cycle, restores the fuel generator adaptation coefficient to 0.3, and recalculates the power allocation based on the current SOC and load. It decides to reduce the power of the fuel generator to 800W, which, together with the 180W photovoltaic power, meets the load and provides moderate charging. The system then smoothly transitions to the normal maintenance phase under parking tilt conditions.

[0060] As can be seen from the detailed description of the above embodiments, the BMS-based intelligent charging and discharging management system for RV batteries of the present invention, through the collaborative design of an attitude perception module, a working condition identification unit, a multi-energy scheduling unit, and a balancing control unit, uses the vehicle's motion state as an important input parameter for charging and discharging management and battery balancing, achieving dynamic optimization of multi-energy power allocation and adaptive matching of balancing modes. This system effectively improves energy utilization efficiency, accelerates battery balancing speed, and reduces balancing power consumption in different driving and parking scenarios, demonstrating good practicality and reliability.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A smart charging and discharging management system for RV batteries based on RV energy management and battery management BMS, characterized in that, The system comprises: A multi-source energy input interface is connected to a DC bus via a power conversion unit, and the DC bus is connected to a battery pack via a bidirectional DC / DC converter. The attitude perception module is used to collect attitude data of the RV body, including roll angle, pitch angle, yaw rate of change and three-axis vibration acceleration. The BMS main control module includes an operating condition identification unit, a multi-energy scheduling unit, and a balance control unit; The operating condition identification unit is used to identify the current operating condition of the RV based on attitude data; The multi-energy dispatching unit is used to calculate the power allocation ratio of each energy source based on the current operating conditions and the electrical parameters of the multi-source energy input interface, and output dispatching instructions to each power conversion unit. The equalization control unit is used to control the equalization actuator to perform sway-assisted equalization based on attitude data and battery cell voltage data when the current operating condition is driving or parking swaying. The BMS main control module is also used to synchronously output the current operating condition identified by the operating condition identification unit to the multi-energy scheduling unit and the equalization control unit. When the equalization control unit detects that the battery pack voltage inconsistency exceeds a preset threshold, it sends an equalization demand signal to the multi-energy scheduling unit. The multi-energy scheduling unit then adds a charging current weight to the power allocation ratio calculation based on the equalization demand signal.

2. The intelligent charging and discharging management system for RV batteries based on BMS according to claim 1, characterized in that, When calculating the power allocation ratio of each energy source, the multi-energy scheduling unit constructs a four-dimensional objective function: Where F1 is the power priority score, F2 is the load demand matching score, F3 is the energy consumption economy score, F4 is the motion posture adaptability score, and , , , are weight coefficients, which represent the weight values ​​of F1, F2, F3, and F4 in the four-dimensional objective function, respectively. Each weight coefficient is a real number between 0 and 1, and +++=1. The motion posture adaptation score F4 is determined based on the current operating conditions: under driving conditions, the adaptation score of the vehicle generator is higher than that of the photovoltaic and mains power; under parking level conditions, the adaptation scores of mains power and photovoltaic are higher than that of the vehicle generator; under parking tilt conditions, the adaptation score of the fuel generator increases according to the equalization demand signal.

3. The intelligent charging and discharging management system for RV batteries based on BMS according to claim 2, characterized in that, The weighting coefficients are dynamically adjusted according to the user preset mode, which includes economic mode, comfort mode and environmental protection mode. In the economic mode, the value of is greater than the value of , and in the environmental mode, the power priority score F1 of photovoltaic is higher than the power priority score F1 of fuel generator.

4. The intelligent charging and discharging management system for RV batteries based on BMS according to claim 1, characterized in that, The attitude sensing module includes multiple MEMS inertial measurement units and multiple tilt sensors, which are distributed at the front, rear, sides, and inside the battery compartment of the RV. The sampling frequency of the attitude sensing module is not less than 100Hz.

5. The intelligent charging and discharging management system for RV batteries based on BMS according to claim 1, characterized in that, The current operating conditions identified by the operating condition identification unit include driving on a flat road, driving uphill, driving downhill, driving while turning, parking at a level position, parking at an angle, and parking swaying. The conditions for identifying the driving and climbing conditions are that the pitch angle is greater than 5 and the vehicle is in a driving state; The conditions for identifying the downhill driving condition are that the pitch angle is < -5 and the vehicle is in motion; The identification condition for the parking tilt condition is that the vehicle is in a parking state and the roll angle or pitch angle is 3. The identification condition for the parking sway condition is that the vehicle is in a parking state and the rate of change of the roll angle is 5 / s.

6. The intelligent charging and discharging management system for RV batteries based on BMS according to claim 1, characterized in that, The battery pack includes multiple battery modules, and each battery module includes multiple battery cells and an equalization actuator; The equalization actuator includes a conventional equalization circuit and a swing-assisted equalization device. The conventional equalization circuit includes a passive equalization resistor array and an active equalization converter. The swing-assisted equalization device includes an elastic support mechanism, a guide mechanism, and a controllable switch array disposed on the mounting base of each battery module. The elastic support mechanism is used to displace the battery module along the tilt direction when the RV body is tilted, and the controllable switch array is used to electrically connect the high-potential battery cell and the low-potential battery cell in the tilt direction according to the instructions of the equalization control unit.

7. The intelligent charging and discharging management system for RV batteries based on BMS according to claim 6, characterized in that, When the current operating condition is a parking level condition and the battery pack voltage inconsistency exceeds a preset threshold, the equalization control unit controls the conventional equalization circuit to perform equalization. When the current operating condition is driving or parking swaying, the equalization control unit controls the swaying auxiliary equalization device to perform equalization. When the current operating condition is a parking tilt condition, the equalization control unit selects to control the conventional equalization circuit or the swing-assisted equalization device to perform equalization based on the magnitude of the battery pack voltage inconsistency. When the voltage inconsistency of the battery pack is greater than 100mV, the conventional equalization circuit is controlled to perform equalization. When the battery pack voltage inconsistency reaches 100mV and exceeds the preset threshold, the swing-assisted balancing device is controlled to perform balancing.

8. The intelligent charging and discharging management system for RV batteries based on BMS according to claim 1, characterized in that, When the equalization control unit controls the swing-assisted equalization device to perform equalization, it calculates the current tilt direction and tilt angle based on the attitude data, determines the spatial position of the high-potential cell and the low-potential cell based on the battery cell voltage data, and controls the controllable switch array to conduct the circuit between the high-potential cell and the low-potential cell when the tilt direction is consistent with the direction where the high-potential cell is located. When the roll angle or pitch angle changes periodically, the equalization control unit controls the controllable switch array to turn on and off synchronously according to the frequency of the periodic change.

9. The intelligent charging and discharging management system for RV batteries based on BMS according to claim 1, characterized in that, The multi-source energy input interface includes an external AC power input interface, a vehicle-mounted fuel generator input interface, a solar photovoltaic panel input interface, and a vehicle generator input interface; The external AC power input interface is connected to the DC bus via an AC / DC converter. The on-board fuel generator input interface is connected to the DC bus via a rectifier unit and a DC-DC converter. The solar photovoltaic panel input interface is connected to the DC bus via an MPPT unit and a DC-DC converter. The vehicle generator input interface is connected to the DC bus via a DC-DC converter.

10. A BMS-based intelligent charging and discharging management system for RV batteries according to claim 9, characterized in that, The multi-energy scheduling unit calculates the power allocation ratio in 5-minute cycles and immediately recalculates the power allocation ratio when the load management module detects a sudden change in load power. The power allocation ratio calculated by the multi-energy dispatching unit is the percentage of the output power of each energy source to the total load power, and the sum of the percentages is 100%.

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