CN103973182B - Method for controlling operation of automotive generator on basis of efficiency and automotive electronic controller - Google Patents

Abstract

The invention relates to automobile electronic technology, in particular to a method for optimizing energy use efficiency by controlling the operation of an automobile engine during automobile driving and an automobile electronic controller based on the method. According to an embodiment of the present invention, the method for controlling the operation of an automobile generator based on efficiency includes the following steps: obtaining the state of charge of the storage battery and the driving speed of the automobile; The electrical state and travel speed determine the degree of reduction in the output voltage of the generator and the amperage to charge the battery.

Description

Efficiency-Based Auto Alternator Operation Control Method and Automotive Electronic Controller

technical field

The invention relates to automobile electronic technology, in particular to a method for optimizing energy use efficiency by controlling the operation of an automobile engine during automobile driving and an automobile electronic controller based on the method.

Background technique

In modern society, automobiles have always been the main force of oil consumption. With the dwindling of fossil fuel resources and the increasing trend of global warming, countries all over the world have set limits on the fuel consumption of cars from the legal and economic aspects. Therefore, how to improve the efficiency of electric energy utilization has always been a core topic of concern in the industry.

The vehicle power supply system mainly consists of an energy storage device (such as a battery or a supercapacitor), an energy conversion device (such as a generator that converts mechanical energy into electrical energy), a starter and a control unit. In the vehicle power supply system, the control unit is the core of the whole system, which is responsible for determining and implementing the appropriate power management strategy according to the working conditions such as power load, battery status and generator status. The starter uses the energy of the battery to start the car engine and make the engine run in the required working state. When the engine is running, it will drive the generator to generate electricity, and supply power to the car's electrical load and charge the battery according to the voltage requirements of the car's electrical system. For example, under the control of the control unit, if the power consumption current of the automobile electrical system is greater than the power supply current of the generator, the battery will be discharged to make up for the insufficient current; If the supply current is supplied, part of the current difference flows into the battery as the charging current of the battery.

FIG. 1 is a schematic diagram showing energy flow in a car. In the figure, the thick solid line represents the electric energy flow, and the thin solid line represents the control signal flow and the detection signal flow. As shown in FIG. 1 , under the control of the automotive electronic controller (ECU) 110, the automotive engine 120 rotates to drive the automotive generator 130 to generate electricity, and the generated electricity can be provided to the battery 140 or to the electrical load 150; another On the other hand, the electric energy stored in the storage battery 140 can also be provided to the electric load 150 and the starter 160 . It can be seen that the generator and battery are important links in the above energy flow process, so how to make them work together with high efficiency and low energy consumption is an important way to reduce fuel consumption.

The industry has proposed a variety of battery power balance methods based on the power load state. These methods generally take the battery SOC state and/or power load state as the monitoring object, and determine whether to The generator charges the battery and/or supplies electricity to the load.

However, it should be pointed out that in order to further optimize the energy utilization efficiency, a more complete control strategy is needed.

Contents of the invention

The purpose of the present invention is to provide an efficiency-based motor generator operation control method, which has the advantages of significantly reducing fuel consumption and simple implementation.

According to one embodiment of the present invention, in an efficiency-based method for controlling the operation of an automobile generator, the automobile generator is electrically coupled with a storage battery, and is driven to rotate by an automobile engine during operation, comprising the following steps:

obtaining the state of charge of the battery and the travel speed of the vehicle; and

If the state of charge is higher than a surplus charge threshold, then determine the reduction degree of the output voltage of the generator and the current intensity for charging the storage battery according to the state of charge and driving speed, wherein the surplus charge Thresholds are dynamically changing.

Preferably, in the above method, the power surplus threshold is determined in the following manner:

T _full =T _ref -αln(V _soc +β)

Among them, T _full is the surplus charge threshold, T _ref is the reference value, V _SOC is the change speed of the state of charge, and α and β are constants greater than 0.

Preferably, in the above method, the reduction degree of the output voltage of the generator is determined in the following manner:

δ＝λ ₁ (SOC-T _full )-λ ₂ (VV _ref ) ²

Among them, δ is the reduction ratio of the output voltage, T _full is the surplus power threshold, SOC is the state of charge, V is the driving speed, and V _ref is the reference value, which means that the vehicle engine operates at the highest fuel efficiency λ ₁ and λ ₂ are constants greater than 0 at the corresponding vehicle speed.

Preferably, in the above method, the current intensity for the generator to charge the storage battery is determined in the following manner: the value range of the deviation degree of the state of charge relative to the full charge threshold is divided into a plurality of intervals , each interval corresponds to a charging current intensity, and thus the corresponding charging current intensity is determined according to the state of charge.

Another object of the present invention is to provide an automotive electronic controller, which has the advantages of significantly reducing fuel consumption and simple implementation.

According to an embodiment of the present invention, an automotive electronic controller includes: an input unit, an output unit, and a processor coupled to the input unit and the output unit, wherein the input unit is configured to receive information related to the state of charge of the battery from a sensor a detection signal related to the driving speed of the vehicle, the output unit is configured to send an instruction generated by the processor to the vehicle generator,

Wherein, the processor is configured to determine the degree of reduction of the output voltage of the generator and charge the storage battery according to the state of charge and the driving speed when it is judged that the state of charge is higher than the full power threshold. The current intensity, wherein the surplus charge threshold is dynamically changed.

The above and other objects and advantages of the present invention will become more fully apparent from the following detailed description taken in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram showing energy flow in an automobile.

FIG. 2 is a flow chart of an efficiency-based method for controlling the operation of an automobile generator according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a physical model of a battery.

FIG. 4 is a flow chart of the SOC calculation method used in the embodiment shown in FIG. 2 .

FIG. 5 is a structural block diagram of an automotive electronic controller according to an embodiment of the present invention.

detailed description

The specific embodiments are described below to illustrate the present invention by referring to the figures. However, it should be understood that these specific embodiments are only exemplary, and have no limiting effect on the spirit and protection scope of the present invention.

In this specification, the word "coupling" should be understood as including the situation of direct transmission of energy or signals between two units, or the situation of indirect transmission of energy or signals via one or more third units, and the Signals include, but are not limited to, those in electrical, optical, and magnetic forms. In addition, terms such as "comprising" and "comprising" indicate that in addition to the units and steps that are directly and explicitly stated in the specification and claims, the technical solution of the present invention does not exclude any elements that are not directly or explicitly stated. The situation of other units and steps. Furthermore, terms such as "first", "second", "third" and "fourth" do not denote the order of elements or values in terms of time, space, size, etc. but merely to distinguish the elements or numerical use.

It should also be pointed out that, for the convenience of illustration, the units in the drawings are not necessarily drawn according to their actual proportions, and the dimensions of the units in the drawings and their ratios do not limit the protection scope of the present invention.

FIG. 2 is a flow chart of an efficiency-based method for controlling the operation of an automobile generator according to an embodiment of the present invention. For the convenience of explanation, the following description takes the energy flow scene in a car shown in FIG. 1 as an example, but it should be understood that the scene shown in FIG. 1 is only schematic.

As shown in FIG. 2 , in step S210 , the vehicle electronic controller 110 first receives the state signal of the battery 140 (such as the voltage, current and temperature of the battery) and the driving speed of the vehicle measured by the sensor. These signals may be in the form of analog signals that are converted to digital signals at the vehicle electronic controller 110 . Optionally, an A/D converter can also be integrated in the sensor, so the digital signal provided to the automotive electronic controller 110 is.

Subsequently, in step S220 , the vehicle electronic controller 110 calculates the SOC (State Of Charge) of the battery 140 according to the received state signal. The calculation process of the state of charge will be described in detail below.

Optionally, in step S220, the change speed of the SOC may also be calculated according to the current SOC and the previous SOC. As will be further described below, when the SOC decreases, this rate of change can be used to determine a dynamically changing early warning threshold.

Then enter step S230, the automotive electronic controller 110 determines whether the SOC of the battery 140 is higher than the surplus power threshold. If it is higher than the surplus power threshold, it indicates that the power of the battery is sufficient, and the probability that the car will fail to start next time due to insufficient power is very small, so go to step S240 to make the car generator enter the power saving mode to take more energy utilization into account efficiency factor, otherwise, go to step S280.

As will be further described below, in the power saving mode, the energy utilization efficiency can be improved by reducing the output voltage of the vehicle generator and/or the charging current to the battery.

In this embodiment, the power generation threshold can be changed dynamically, which depends on the change speed of the SOC. In particular, when the SOC increases at a faster speed, the power saving threshold is set lower to enter the power saving mode early, and when the SOC increases at a slower speed or becomes smaller, the power saving threshold can be set to Set it higher to delay entering battery saver mode.

After in-depth research, the inventors of the present invention found that when the power-saving threshold is determined according to the following formula, it can be well determined whether to enter the power-saving mode:

T _full ＝ T _ref -αln(V _soc +β) (1)

Here, T _full is the surplus charge threshold, T _ref is the reference value, V _SOC is the change speed of the state of charge, and α and β are constants greater than 0, which can be determined through experiments.

In step S240 , the automotive electronic controller 110 calculates the drop amount of the output voltage of the automotive generator 130 .

The inventors of the present invention have found after in-depth research that it is beneficial for the improvement of energy efficiency when the degree of decline of the output voltage of the automobile generator is determined according to the following formula:

δ＝λ ₁ (SOC-T _full )+λ ₂ (VV _ref ) ² (2)

Among them, δ is the reduction ratio of the output voltage (that is, the ratio of the voltage drop to the current output voltage), T _full is the surplus power threshold, SOC is the state of charge, V is the driving speed, and V _ref is the reference The value, for example, can be taken as the vehicle speed corresponding to the vehicle engine running at the highest fuel efficiency, and λ1 and λ2 are constants greater than 0, which can be determined by experiments.

It is worth pointing out that at the same maximum fuel efficiency, the reference value V _ref may also be different, for example, because the vehicle engine is in a different speed and gear state, but the above situation does not hinder the principle of the present invention Applications.

Then enter step S250 , the vehicle electronic controller 110 further calculates the current intensity of the vehicle generator 130 charging the battery 140 . In this embodiment, the magnitude of the charging current can be determined according to the deviation degree of the state of charge relative to the full charge threshold (that is, the difference between the SOC and the full charge threshold). Specifically, the value range of the degree of deviation may be divided into multiple intervals, each interval corresponds to a charging current intensity, and thus the corresponding charging current intensity is determined according to the SOC calculated in step S220.

Then enter step S260, the vehicle electronic controller 110 generates a control command and sends the generated command to the vehicle generator 130, the control command includes information about the degree of output voltage drop and the intensity of the charging current. In this embodiment, the generating current intensity is equal to the sum of the charging current intensity determined in step S240 and the current intensity required by the electric load 150 .

Next, in step S270 , the car generator 130 operates according to the command received from the car electronic controller 110 .

As another branch, in step S280 , the vehicle electronic controller 110 generates a control command not to enter the energy-saving mode and sends the control command to the vehicle generator 130 . Then enter step S270 , in response, the vehicle generator 130 operates according to the command received from the vehicle electronic controller 110 .

The calculation process of the SOC is described below.

Commonly used SOC calculation methods mainly include the open circuit voltage method and the current integration method (also known as the ampere-hour method).

The basic idea of the open circuit voltage method is to first establish a relationship model that reflects the terminal voltage, current and electromotive force when the battery is working, and then obtain the corresponding electromotive force according to the measured voltage and current to determine the SOC using the relationship curve between the electromotive force and SOC. The advantage of this method is that it is simple and easy to implement, but due to the self-recovery effect and "plateau" phenomenon of the battery, the estimated SOC sometimes differs greatly from the actual value.

The current integration method regards the battery as a "black box" for energy exchange with the outside, and records the cumulative change of battery power by integrating the current in and out of the battery over time. This method is more adaptable than the open-circuit voltage method because it does not need to consider changes in the internal structure and state of the battery. But the disadvantage is that the initial value of SOC is often difficult to determine and the cumulative error will continue to increase as time goes by, resulting in a larger error in the calculation result of the SOC value. In addition, when calculating SOC with the current integration method, an accurate estimate of the charge-discharge coefficient is required. When the battery working environment changes greatly, it is difficult to determine the charge-discharge coefficient accurately and in time, which will also lead to problems in the final calculated SOC result. big error.

The inventor of the present invention proposes a SOC calculation method, which introduces fuzzy logic to make the calculation result more accurate, which will be described in detail below.

From the point of view of electricity, the state of charge SOC of the battery can be defined as follows:

$\mathrm{<span\; class="notranslate">\; SOC</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Q</span>}}{{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Q</span>}}{{\mathrm{<span\; class="notranslate">\; \&epsiv;Q</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

Among them, Q is the current remaining capacity of the battery, Q _N is the rated capacity of the battery when it leaves the factory, Q _a is the attenuation capacity of the battery, ε is the attenuation factor, which is a variable less than 1, and Q _N represents the actual maximum power that the battery can discharge . It can be seen from the above that SOC is a variable whose value ranges from 0-1.

Studies have shown that the factors that affect the remaining capacity of the battery include charge and discharge rate (that is, charge and discharge current), self-discharge, and temperature. Among them, the greater the current, the less electricity can be released. The self-discharge of the battery refers to the phenomenon that the remaining capacity of the battery decreases during the storage process. The factors that lead to self-discharge include corrosion of the electrode, dissolution of the active material, and disproportionation of the electrode. The effect of temperature on the remaining capacity of the battery is because the activity of the electrode material and the electrical mobility of the electrolyte are closely related to the temperature. Generally, the discharge capacity of the battery at high temperature is significantly greater than that at low temperature.

After in-depth research, the inventors of the present invention have found that the change of the attenuation factor with time and/or the number of charge and discharge times will be fully reflected in the external characteristics of the storage battery, so the SOC can be simplified as a function of the operating voltage, working A state quantity determined by current and temperature.

In addition, the inventors of the present invention realized that it is difficult to establish an accurate mathematical model between the SOC of the storage battery and the operating voltage, operating current and temperature, and although the change of the decay factor with time is very complicated and the amount of change may be large, this Change is a process with a long lag. Based on the above knowledge, the inventors of the present invention introduced fuzzy logic to describe the relationship between SOC and operating voltage, operating current and temperature.

In the model based on fuzzy logic, fuzzy reasoning is based on the knowledge base expressed as fuzzy rules, and the number of fuzzy rules depends on the number of input and output physical quantities and the required control precision. For example, for a commonly used two-input, one-output model, if each input quantity is divided into five levels, 25 rules are required to cover all situations. As the number of input and output variables increases, the inference rules will increase non-linearly, which will consume a lot of computing resources and reduce the computing speed. The inventors of the present invention propose that the mathematical model of the SOC is simplified into two variables of voltage and temperature by using the operating current to correct the operating voltage, thereby reducing the computational complexity. This is further described below.

Generally, there is an average load current for the vehicle battery, which can be regarded as the typical working current or the standard working current of the battery. The working current of this standard can be, for example: 1) the arithmetic mean value of the working current under various working conditions; or 2) the weighted average value of the working current according to the occurrence probability of the corresponding working state; or 3) the actual measurement The average value of the operating current over a period of time. In one embodiment of the present invention, according to the measured working current, the measured working voltage is converted into the working voltage under the standard working power (hereinafter also referred to as the corrected value of the working voltage).

FIG. 3 is a schematic diagram of a physical model of a battery. According to Figure 4, the following equation (4) can be obtained:

U _I ＝EI×(R+R ₁ ) (4)

Among them, E is the electromotive force of the battery, I is the measured working current, U _I is the working voltage measured under the working current _I , R and R1 are the ohmic internal resistance and polarization internal resistance when the battery is discharged at the working current I resistance.

The correction value of the above operating voltage UI is calculated according to the following formula (5):

U _I,m = U _I +(II ₀ )×λ(I) (5)

Among them, U _I is the working voltage measured under the working current I, U _I,m is the correction value of the working voltage U _I , I is the measured working current, I ₀ is the standard working current, λ(I) is the The magnitude of the change in current, which can be determined experimentally.

For example, the discharge curves of different operating currents of the battery at the same temperature (that is, the change curve of the battery operating voltage and SOC or the constant current discharge curve) can be measured by the constant current discharge experiment, and various operating currents can be obtained by the following formula (6) The following corresponding λ(I):

$\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; SOC</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}^{\mathrm{<span\; class="notranslate">\; SOC</span>}}}{\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Among them, I ₀ is the standard operating current, I is the operating current with other values, U ^SOC _I is the operating voltage under the operating current I when the SOC takes a certain value, U ^SOC _I0 is the standard operating current when the SOC takes the same value Operating voltage at I ₀ .

It is worth pointing out that the inventor found that for any two curves in the constant current discharge curve, within the SOC range of 0-100%, their vertical distance (that is, the difference between the operating voltage at the same SOC under different operating currents) difference) remains basically unchanged, and it can be considered that λ(I) is not related to SOC, so in the above formula (6), USOC _I and ^USOC _I0 under any ^SOC can be selected to calculate λ(I). In addition, since λ(I) is not sensitive to changes in temperature, the temperature factor was not considered when calculating the correction value of the operating voltage above.

The λ(I) under various operating currents can be stored in the memory in the form of a table, so as to be recalled when calculating the corrected value of the operating voltage. On the other hand, the fitting algorithm can also be used to obtain the empirical formula between λ(I) and the working current from multiple constant current discharge curves, so that λ(I) can be obtained by using the empirical formula when calculating the correction value.

Fig. 4 is a flow chart of the SOC calculation method according to one embodiment of the present invention.

Referring to FIG. 4 , in step 411 , the operating current I of the battery, the operating voltage U _I and the operating temperature T under the operating current are input. The working current I and the working voltage U _I can be obtained by a measuring circuit, and the working temperature T can be obtained by a temperature sensor installed near or above the storage battery. The measuring circuit and the sensor can be connected to the CAN bus, so that the automotive electronic controller 110 can obtain the measured values of the above working states via the bus.

Then enter step 412, judge whether the operating current is equal to the standard operating current, or judge whether the difference with the standard operating current is in a preset range, if the judgment result is true, then enter step 413, otherwise, enter step 414 .

In step 414 , the λ(I) under the current working circuit I is obtained, for example, by means of table lookup.

Then enter step 415 , for example, calculate the operating voltage correction value U _I,m of the operating voltage U _I under the standard operating current by using the above formula (5). Enter step 413 after completing step 415 .

In step 413, it is judged whether the operating voltage correction value U _{I, m} and the operating temperature T exceed the respective predetermined value ranges, if they are all within the respective predetermined value ranges, then enter step 417, otherwise, Then it indicates that there is an abnormal situation, and therefore enters step 416 .

In step 416, a warning message will be generated to alert the user of a possible abnormal operating condition of the battery or a possible failure of the measurement circuit and sensor.

In step 417, the respective membership functions of the working voltage correction value U _I,m and the working temperature T are used to determine their fuzzy values.

Then enter step 418, use the fuzzy inference rules to determine the fuzzy value of SOC according to the working voltage correction value U _I,m obtained in step 417 above and the fuzzy value of working temperature T.

The rules of fuzzy reasoning can be formulated according to the relationship between SOC and voltage under different operating currents and the influence of temperature on the discharge curve, and can be modified repeatedly through simulation experiments. For example, the following inference rules can be used:

(1) If the fuzzy value of the correction value of the operating voltage is L, then the fuzzy value of the SOC is L;

(2) If the fuzzy value of the correction value of the working voltage is M and the fuzzy value of the working temperature is Cold, then the fuzzy value of the SOC is L;

(3) If the fuzzy value of the correction value of the working voltage is M and the fuzzy value of the working temperature is Warm, then the fuzzy value of the SOC is M;

(4) If the fuzzy value of the correction value of the working voltage is M and the fuzzy value of the working temperature is Hot, then the fuzzy value of the SOC is M;

(5) If the fuzzy value of the correction value of the working voltage is H and the fuzzy value of the working temperature is Cold, then the fuzzy value of the SOC is M;

(6) If the fuzzy value of the correction value of the working voltage is H and the fuzzy value of the working temperature is Warm, then the fuzzy value of the SOC is H;

(7) If the fuzzy value of the correction value of the working voltage is H and the fuzzy value of the working temperature is Hot, then the fuzzy value of the SOC is H.

It is worth pointing out that the above reasoning rules are only indicative, and in order to obtain better SOC estimation results, it needs to be optimized according to simulation experiments or actual experiments.

Then enter step 419 , use the defuzzification algorithm to calculate the precise value of the SOC of the storage battery according to the fuzzy value of SOC obtained in the above step 518 .

Then enter step 420, and output the SOC value calculated by using the defuzzification algorithm.

There are many defuzzification algorithms, including but not limited to min-max, max-max, center of gravity, bisection, and median maximum. An appropriate deblurring algorithm can be selected according to the availability of computing resources and the required computing precision.

FIG. 5 is a structural block diagram of an automotive electronic controller according to an embodiment of the present invention.

As shown in FIG. 5 , the automotive electronic controller 50 according to this embodiment includes an input unit 510 , a processor 520 , a DRAM 530A, a nonvolatile memory 530B and an output unit 540 .

The input unit 510 is coupled with sensors and switches 611 - 61 n located outside the automotive electronic controller 50 . Preferably, the input unit 510 is connected to the sensors and switches 611-61n via a bus (eg CAN bus). Sensors 611-61n include, but are not limited to, battery voltage sensors, battery current sensors, battery temperature sensors, vehicle speed sensors, engine speed and crankshaft position sensors, air flow/intake pressure sensors, throttle position sensors, and torque sensors. Various feedback signals required for control are provided to the automotive electronic controller 50 . The output unit 540 sends various control commands generated by the processor to the automobile generator 130 . Preferably, it is also connected to the automobile generator 130 via a bus (eg CAN bus).

Processor 520 is coupled with input unit 510, DRAM 530A, nonvolatile memory 530B and output unit 540, as the core unit of automotive electronic control 60, it according to the control program and standard data stored in nonvolatile memory 530B, to The input unit 510 performs preprocessing, analysis, and judgment on signals received from sensors and switches, generates corresponding control commands, and sends the control commands to the controlled equipment (such as the generator 130 in FIG. 5 ) through the output unit 540 .

The working principle of the automotive electronic controller shown in Fig. 5 is described below.

When the processor 520 of the automotive electronic controller 50 is powered on, it loads the control program from the non-volatile memory 530B into the DRAM 530A. The control program here includes a computer program for realizing steps S210-S260 and S280 in the method shown in FIG. 2 .

The input unit 510 regularly or irregularly receives detection signals and switch signals from the sensors and switches 611 - 61 n and transmits them to the processor 520 . When the processor 520 receives the state signal of the battery (such as voltage, current and temperature signals) and the vehicle speed signal, it executes the step S220 of calculating the SOC and its changing speed and the step S230 of judging whether the SOC is lower than the surplus power threshold . If it is judged that the SOC of the storage battery is higher than the surplus power threshold, the step S240 of calculating the degree of output voltage drop and the step S250 of calculating the intensity of the charging current are executed, and then step S260 is executed to generate a control command and send a control command to the automobile generator 130 via the output unit 540 command, so that the car generator enters the power-saving mode and works according to the set parameters. If it is determined that the threshold is not higher than the REC threshold, step S280 is executed to generate a control command not to enter the power saving mode and send the control command to the automobile generator 130 through the output unit 540 .

Since the invention can be embodied in various forms without departing from the essential characteristics of the invention, the embodiments are illustrative rather than restrictive, since the scope of the invention is defined by the appended claims rather than by All changes that come within the metes and bounds of the claims as defined by the description, or equivalents of such metes and bounds, are hereby embraced by the claims.

Claims (6)

1. a kind of automobile current generator progress control method based on efficiency, described automobile current generator and accumulator electrical couplings, and And operationally rotation is driven by automobile engine, comprise the following steps：

Obtain the state-of-charge of described accumulator and the travel speed of automobile；And

If described state-of-charge is higher than to be full of electric threshold value, described electromotor is determined according to described state-of-charge and travel speed The reduction degree of output voltage and the current intensity charging to described accumulator, wherein, described to be full of electric threshold value be dynamic change,

Wherein, described it is full of electric threshold value and determines as follows：

T_full=T_ref-αln(V_soc+β)

Wherein, T_fullFor being full of electric threshold value, T_refOn the basis of be worth, V_SOCFor the pace of change of state-of-charge, α and β is the constant more than 0.

2. the method for claim 1, wherein determine the reduction journey of the output voltage of described electromotor as follows Degree：

δ=λ₁(SOC-T_full)-λ₂(V-V_ref)²

Wherein, δ is the reduction ratio of described output voltage, T_fullFor being full of electric threshold value, SOC is state-of-charge, and V is described to travel speed Degree, V_refOn the basis of be worth, its corresponding automobile driving speed when being run with highest fuel efficiency for described automobile engine, λ₁ And λ₂It is the constant more than 0.

3. the method for claim 1, wherein determine what described electromotor charged to described accumulator as follows Current intensity：Described state-of-charge is divided into multiple intervals with respect to the span of the described departure degree being full of electric threshold value, Each interval corresponds to a strength of charging current, determines corresponding strength of charging current thus according to described state-of-charge.

4. a kind of automobile electronic controller, including：Input block, output unit and the place coupling with input block and output unit Reason device, wherein, described input block is configured to relevant with storage battery charge state and automobile driving speed from sensor reception Detection signal, described output unit is configured to send, to automobile current generator, the instruction that generated by described processor,

Wherein, described processor is configured as judging described state-of-charge when being higher than to be full of electric threshold value, according to described state-of-charge The current intensity charge with the reduction degree of the output voltage that travel speed determines described electromotor and to described accumulator, its In, it is described that to be full of electric threshold value be dynamic change,

Wherein, described it is full of electric threshold value and determines as follows：

T_full=T_ref-αln(V_soc+β)

Wherein, T_fullFor being full of electric threshold value, T_refOn the basis of be worth, V_SOCFor the pace of change of state-of-charge, α and β is the constant more than 0.

5. automobile electronic controller as claimed in claim 4, wherein, determines the output electricity of described electromotor as follows The reduction degree of pressure：

δ=λ₁(SOC-T_full)+λ₂(V-V_ref)²

Wherein, δ is the reduction ratio of described output voltage, T_fullFor being full of electric threshold value, SOC is state-of-charge, and V is described to travel speed Degree, V_refOn the basis of be worth, its corresponding automobile driving speed when being run with highest fuel efficiency for described automobile engine, λ₁ And λ₂It is the constant more than 0.

6. automobile electronic controller as claimed in claim 4, wherein, determines described electromotor to described storage as follows The current intensity that battery charges：Described state-of-charge is divided into respect to the span of the described departure degree being full of electric threshold value Multiple intervals, each interval corresponds to a strength of charging current, determines the corresponding electricity that charges thus according to described state-of-charge Intensity of flow.