A vehicle intelligent power generation method based on the OCV of a storage battery

Abstract

The present invention discloses a vehicle intelligent power generation method based on the OCV of a storage battery. After the vehicle is powered on, the static time and the initial open-circuit voltage are obtained; the initial SOC value is determined based on the static time and the initial open-circuit voltage; whether to enter the intelligent power generation management is determined according to the initial SOC value. After the vehicle starts, the present invention judges the initial state of the storage battery through the voltage of the storage battery before starting and the static time, and estimates the electric energy range of the storage battery through the charge and discharge time within this cycle, and controls the time for the generator to enter and exit the intelligent power generation mode based on this, so as to achieve the purpose of reducing power consumption and maintaining the balance of electric energy. The scheme is simple, easy to implement and has low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobiles, and particularly relates to a vehicle intelligent power generation method based on the OCV of a storage battery. Background Art

[0002] In the automotive industry, especially in the commercial vehicle industry, most use traditional low-voltage non-adjustable generator systems. The generator charges at a constant voltage, unable to achieve intelligent variable output of the generator, and lacking detection and protection of the storage battery system. For those with intelligent power generation control systems for lead-acid batteries, most are also based on storage battery sensors, using the real-time dynamic SOC value of lead-acid batteries as the judgment basis for intelligent power generation control. By monitoring the SOC value and combining the current vehicle conditions, different generator output states are controlled.

[0003] The core of the existing solution relies on lead-acid battery sensors to estimate the dynamic SOC value of the storage battery. Due to the chemical characteristics of lead-acid batteries, the battery SOC cannot be directly measured and can only be estimated by parameters such as battery terminal voltage, charge and discharge current, and internal resistance. These parameters are also affected by various uncertain factors such as battery aging, environmental temperature changes, and vehicle driving conditions. Therefore, the error between the dynamically monitored value and the actual value of the SOC is relatively large, causing great difficulty in formulating control strategies. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies existing in the above background art and provide a vehicle intelligent power generation method based on the OCV of a storage battery to achieve the purpose of reducing power consumption and maintaining power balance.

[0005] The technical solution adopted by the present invention is: a vehicle intelligent power generation method based on the OCV of a storage battery. After the vehicle is powered on, the static time and the initial open-circuit voltage are obtained.

[0006] Based on the static time and the initial open-circuit voltage, the initial SOC value is determined.

[0007] According to the initial SOC value, it is determined whether to enter intelligent power generation management.

[0008] Further, each time the vehicle is powered off, the power-off timestamp is recorded; when the vehicle is powered on next time, the power-on timestamp is recorded, and the difference between the previous power-off timestamp and the current power-on timestamp is the static time.

[0009] Further, the initial SOC value is determined by looking up the static time, the initial open-circuit voltage, and the environmental temperature MAP table.

[0010] Further, when the initial SOC value ≥ B%, it is determined to enter intelligent power generation management.

[0011] Further, after entering the intelligent power generation management, when the following Condition 1 is met, exit the intelligent power generation management; after exiting the intelligent power generation management, when the following Condition 2 is met, enter the intelligent power generation management again;

[0012] Condition 1: (Discharge cumulative time T1 - Generation cumulative time T2) > ΔT;

[0013] Condition 2: (Discharge cumulative time T1 - Generation cumulative time T2) ≤ ΔT.

[0014] Further, when the initial SOC value < B%, it is determined not to enter the intelligent power generation management.

[0015] Further, when the following Condition 1 is met, enter the intelligent power generation management; after entering the intelligent power generation management, when the following Condition 2 is met, exit the intelligent power generation management again;

[0016] Condition 1: (Generation cumulative time T2 - Discharge cumulative time T1) > ΔT;

[0017] Condition 2: (Generation cumulative time T2 - Discharge cumulative time T1) ≤ ΔT.

[0018] Further, the discharge cumulative time T1 is the cumulative shutdown time of the generator since the vehicle is powered on, and the generation cumulative time T2 is the cumulative startup time of the generator since the vehicle is powered on.

[0019] Further, the intelligent power generation management is: when it is judged that the vehicle is in an accelerating state, control to turn off the generator, otherwise control to turn on the generator.

[0020] Furthermore, when any one or more of the following conditions are met, it is judged that the vehicle is in an accelerating state:

[0021] 1) Throttle opening signal > A1;

[0022] 2) Throttle change rate > A2;

[0023] 3) Calculated vehicle acceleration value > A3;

[0024] The A1 is the throttle opening calibration value, A2 is the throttle change rate calibration value, and A3 is the vehicle acceleration calibration value.

[0025] After the vehicle starts, the present invention judges the initial state of the battery through the battery voltage before starting and the standing time, and estimates the electric energy range of the battery through the charge and discharge time within this cycle, and controls the time for the generator to enter and exit the intelligent power generation mode based on this, so as to achieve the purpose of reducing power consumption and maintaining electric energy balance. The scheme is simple and easy to implement.

[0026] The present invention formulates the control strategy of the generator based on the initial battery state (OCV-SOC) and the cumulative charge and discharge time in the cycle interval. Different from the dynamic monitoring control, this method does not rely on the dynamic SOC value, so there is no need to add a battery sensor, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a vehicle intelligent power generation system based on the OCV of a storage battery according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following further describes the specific embodiments of the present invention with reference to the drawings. It should be noted here that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation to the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] In the case of using "including", "having" and "comprising" described in this specification, unless otherwise used, it may also have another part or other parts, and the terms used can generally be singular but can also represent plural forms.

[0030] The features of the various embodiments of the present invention can be partially or fully combined or spliced with each other, and can be implemented in various different configurations as can be fully understood by those skilled in the art. The embodiments of the present invention can be implemented independently of each other, or can be implemented together in a mutually dependent relationship.

[0031] The present invention provides a vehicle intelligent power generation method based on the OCV of a storage battery. After the vehicle is powered on, the static time and the initial open circuit voltage are obtained;

[0032] Based on the static time and the initial open circuit voltage, the initial SOC value is determined;

[0033] According to the initial SOC value, it is determined whether to enter the intelligent power generation management.

[0034] In the above solution, each time the vehicle is powered off, the power-off timestamp is recorded before the vehicle controller enters the sleep state; when the vehicle is powered on next time (i.e., enters the acc or on gear), the power-on timestamp is recorded, then the difference between the last power-off timestamp and the current power-on timestamp is the static time. At the same time, when the vehicle turns on the main power switch, the voltage value at the current moment is recorded as the initial open circuit voltage (OCV). The open circuit voltage (OCV), that is, the terminal voltage of the battery in the open circuit state, generally has a certain monotonic relationship with the battery SOC.

[0035] The relationship between the standing time, open circuit voltage (OCV), ambient temperature, and state of charge (SOC) of the battery is obtained through offline experiments, and the initial SOC of the battery is estimated by fitting or looking up a table. This method requires measuring the open circuit voltage under open circuit conditions, and it is necessary to wait for a period of time to ensure the estimation accuracy. Therefore, its scope of use is limited. Generally, before the vehicle starts (when there is no charging or discharging current in the battery), this method is used to estimate the initial SOC value. Therefore, in the present invention, after the vehicle starts, the initial SOC value is determined by looking up the MAP table of the standing time, initial open circuit voltage, and ambient temperature, and the initial state range of the battery is obtained (SOC≥A%, indicating an excess of power; SOC≥B%, indicating sufficient power; SOC<B, indicating insufficient power, where A, B, and C are all calibrated values).

[0036] State of charge (SOC), that is, the state of charge, is used to reflect the remaining capacity of the battery. Numerically, it is defined as the ratio of the remaining capacity to the battery capacity, usually expressed as a percentage, and its value range is 0 to 1. When SOC = 0, it means the battery is completely discharged, and when SOC = 1, it means the battery is completely full.

[0037] In the above solution, A: When the initial SOC value≥B%, it indicates sufficient power, and the control system determines to enter intelligent power generation management. B: When the initial SOC value<B%, the control system determines that this start cycle will default to enter the full power generation mode, controls the generator to continuously generate power, and determines not to enter intelligent power generation management.

[0038] In the above solution, in order to better protect the storage battery and avoid the battery from being in a state of power failure, after entering the intelligent power generation mode, for both situations A and B, after meeting certain conditions, the intelligent power generation management will be exited, specifically as follows:

[0039] For situation A, after entering intelligent power generation management, when condition 1 is met, the intelligent power generation management is exited; after exiting the intelligent power generation management, when condition 2 is met, the intelligent power generation management is entered again. For situation B, when condition a is met, the intelligent power generation management is entered; after entering the intelligent power generation management, when condition b is met, the intelligent power generation management is exited again. That is, the control system of the present invention can control the real-time switching between entering and exiting the intelligent power generation management according to the cumulative discharge time and cumulative power generation time.

[0040] Condition 1: (Cumulative discharge time T1 - Cumulative power generation time T2)>△T;

[0041] Condition 2: (Cumulative discharge time T1 - Cumulative power generation time T2)≤△T.

[0042] Condition a: (Cumulative power generation time T2 - Cumulative discharge time T1)>△T;

[0043] Condition b: (Cumulative power generation time T2 - Cumulative discharge time T1) ≤ ΔT.

[0044] In the above solution, the cumulative discharge time T1 is the cumulative shutdown time of the generator since the vehicle is powered on, and the cumulative power generation time T2 is the cumulative startup time of the generator since the vehicle is powered on. When the vehicle is powered off, both the cumulative discharge time T1 and the cumulative power generation time T2 are reset to zero.

[0045] In the above solution, the intelligent power generation management is as follows: when it is determined that the vehicle is in an accelerating state, control to turn off the generator (i.e., stop the generator output and be in a discharging state); while in other driving states, control to turn on the generator (i.e., turn on the generator output and be in a continuous power generation state).

[0046] In the above solution, when any one or more of the following conditions are met, it is determined that the vehicle is in an accelerating state:

[0047] 1) Throttle opening signal > A1;

[0048] 2) Throttle change rate > A2;

[0049] 3) Calculated value of vehicle acceleration > A3;

[0050] A1 is the calibrated value of the throttle opening, A2 is the calibrated value of the throttle change rate, and A3 is the calibrated value of the vehicle acceleration.

[0051] As Figure 1 shown, the present invention also provides an intelligent power generation system for implementing the above intelligent power generation method, including a storage battery, a storage battery initial voltage detection module, a storage battery power judgment module, a vehicle driving state detection module, a storage battery power protection module, a generator power generation control module, a generator drive module, a storage battery charging display and fault alarm module, a motor, and an instrument.

[0052] Among them, the storage battery initial voltage detection module detects the initial open-circuit voltage when the vehicle is powered on, and the storage battery power judgment module determines the initial SOC value of the storage battery according to the initial open-circuit voltage and the standing time; the vehicle driving state monitoring module detects the driving state of the vehicle, including information such as the throttle opening signal, the throttle change rate, and the vehicle acceleration; the generator power generation control module intelligently controls the working state of the generator (i.e., whether to enter the intelligent power generation management) according to the initial SOC value of the storage battery and the driving state of the vehicle.

[0053] During intelligent power generation management, the storage battery power protection module determines when to exit the intelligent power generation management according to the cumulative discharge time T1 and the cumulative power generation time T2, and performs power feeding protection on the storage battery; the storage battery charging display and fault alarm module determines whether there is a fault in the storage battery according to the initial open-circuit voltage of the storage battery, and performs fault alarm display on the instrument when necessary.

[0054] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the present disclosure. The appended method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy recited.

[0055] Those skilled in the art will also appreciate that the various illustrative logical blocks, units, and steps listed in the embodiments of the present invention can be implemented by electronic hardware, computer software, or a combination of both. To clearly show the interchangeability of hardware and software, the various illustrative components, units, and steps have been generally described in terms of their functions. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the overall system. Those skilled in the art can use various methods to implement the described functions for each specific application, but such implementation should not be construed as exceeding the scope of the embodiments of the present invention.

[0056] The various illustrative logical blocks or units described in the embodiments of the present invention can be implemented or operated to perform the described functions by a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of the above designs. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other similar configuration.

[0057] The above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An intelligent power generation method for vehicles based on the OCV of a storage battery, characterized in that: After the vehicle is powered on, obtain the static time and the initial open-circuit voltage; Determine the initial SOC value based on the static time and the initial open-circuit voltage; Determine whether to enter intelligent power generation management according to the initial SOC value; Control real-time switching between entering intelligent power generation management and exiting intelligent power generation management according to the cumulative discharge time and the cumulative power generation time; When the initial SOC value ≥ B%, determine to enter intelligent power generation management; after entering intelligent power generation management, when the following condition 1 is met, exit intelligent power generation management; after exiting intelligent power generation management, when the following condition 2 is met, enter intelligent power generation management again; Condition 1: (Cumulative discharge time T1 - Cumulative power generation time T2) > ΔT; Condition 2: (Cumulative discharge time T1 - Cumulative power generation time T2) ≤ ΔT; When the initial SOC value < B%, determine to enter the full power generation mode and do not enter intelligent power generation management; when the following condition a is met, enter intelligent power generation management; after entering intelligent power generation management, when the following condition b is met, exit intelligent power generation management again; Condition a: (Cumulative power generation time T2 - Cumulative discharge time T1) > ΔT; Condition b: (Cumulative power generation time T2 - Cumulative discharge time T1) ≤ ΔT; The cumulative discharge time T1 is the cumulative shutdown time of the generator since the vehicle was powered on, and the cumulative power generation time T2 is the cumulative startup time of the generator since the vehicle was powered on; The intelligent power generation management is: when it is judged that the vehicle is in an accelerating state, control to turn off the generator, otherwise control to turn on the generator.

2. The vehicle intelligent power generation method based on the OCV of the storage battery according to claim 1, characterized in that: Each time the vehicle is powered off, record the power-off timestamp; when the vehicle is powered on next time, record the power-on timestamp, and the difference between the last power-off timestamp and the current power-on timestamp is the static time.

3. The vehicle intelligent power generation method based on the OCV of the storage battery according to claim 1, wherein: Determine the initial SOC value by looking up the static time, initial open-circuit voltage, and ambient temperature MAP table.

4. The vehicle intelligent power generation method based on the OCV of the storage battery according to claim 1, wherein: When any one or more of the following conditions are met, it is judged that the vehicle is in an accelerating state: 1) Throttle opening signal > A1; 2) Throttle change rate > A2; 3) Calculated vehicle acceleration value > A3; The A1 is the throttle opening calibration value, A2 is the throttle change rate calibration value, and A3 is the vehicle acceleration calibration value.

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