A kind of power supply system for automobile and method of work thereofTechnical field
The invention belongs to the current conversion field, a kind of automobile-used high pressure of specific design turns power supply system for automobile and the method for work thereof of low pressure.
Background technology:
In hybrid vehicle, low voltage generator is very low for the efficiency that charges a battery, institute thinks the raising rate of economizing gasoline, low voltage generator can be replaced with to the electric power system that efficiency is higher is DC converter, after the energy conversion in electrokinetic cell or super capacitor, to the low tension battery charging, also give the power supply of car load low-pressure system simultaneously.Now just produce contradiction, if the power of electric power system is excessive, can cause battery charge excessive, had a strong impact on the life-span of storage battery; If power is too little, can only meet so the needs of charge in batteries, be not enough to again the need for electricity to the car load low-pressure system.Traditional automobile-used low-voltage power supply system is controlled and is produced PWM driving switch pipe by the PWM controller, form powerful square wave, convert the square-wave pulse needed to through transformer, form the direct current output needed through rectifying and wave-filtering, through feedback control loop, conditioning is sent to again the duty ratio that the PWM controller is controlled PWM to the electric current and voltage of output again, but because the output current of supply convertor can only be the limits value of a maximum, while being used for to Full Vehicle System, electric current too conference seriously shortens useful life of battery, and electric current is too little can not meet power demands again.
Summary of the invention:
The objective of the invention is to overcome deficiency of the prior art, by increasing charging current feedback control loop and control module, provide a kind of and can guarantee that automobile-used low-voltage equipment need for electricity use can guarantee and power supply system for automobile and the method for work thereof in the useful life of Vehicular battery.
Its technical scheme is:
A kind of power supply system for automobile, comprise power supply, PWM controller, power model, transformer, rectification filtering module, also comprises current feedback loop, voltage feedback loop, charging current feedback control loop, control module; Power supply is connected to the input of power model, and power model is connected to the elementary E of transformer, and transformer secondary output F is connected to the output of rectification filtering module; Rectification module be connected to respectively low-voltage equipment and battery, the output, the battery that show as low-voltage equipment, rectification filtering module are connected in twos and form common node A, the output of PWM controller is connected to the control end of power switch pipe, electrical cable between the output of common node A and rectification filtering module is provided with the first current sensor, is provided with the second current sensor on the electrical cable between common node A and battery; The input that exports current feedback loop to of the first current sensor, the second current sensor exports the input that charging current is fed back electric loop to, the input of voltage feedback loop is connected with common node A, and the output of current feedback loop, voltage feedback loop, charging current feedback control loop is connected to respectively the input of PWM controller; Control module comprises MCU single-chip microcomputer, analog to digital converter, digital to analog converter; The first current sensor, the second current sensor also export respectively the input of analog to digital converter to, the input of analog to digital converter is connected to common electrical node A, the output of analog to digital converter exports the MCU single-chip microcomputer to, the MCU single-chip microcomputer is connected to the input of digital to analog converter, and the output of digital to analog converter is connected to respectively reference voltage input terminal B, the voltage feedback loop reference voltage input terminal C of current feedback loop, the reference voltage input terminal D of charging current feedback control loop.
Power model consists of power switch pipe and bridge circuit.
Rectification filtering module consists of the current rectifying and wave filtering circuit structure, and the current rectifying and wave filtering circuit structure of using is general current rectifying and wave filtering circuit structure, and for example diode rectifier circuit adds the LC filter circuit, or other general current rectifying and wave filtering circuit structures.
Connected mode between each parts in the car electric power system is electrical connection.
Power supply output high-tension current is to power model, thereby PWM controller output pwm signal to power model driving power module is converted into high-voltage square-wave by the high-tension current of power supply output, high-voltage square-wave is converted into the low pressure square wave through transformer, the low pressure square wave is converted into low-voltage DC after rectification filtering module, and low-voltage DC is respectively the low-voltage equipment power supply, is the battery charging; The charging feedback control loop feeds back to the PWM controller by the charging current induced signal of battery, current feedback loop feeds back to the PWM controller by the current sensing signal of rectification filtering module output, and the voltage induced signal feedback that voltage feedback loop is exported rectification filtering module is to the PWM controller; Control module is respectively to charging current feedback control loop, current feedback loop, voltage feedback loop output voltage reference signal, and the charging current of output current, output voltage and the battery of rectification filtering module is gathered and detects, control module is carried out data communication by CAN bus and other mobile units simultaneously.
The MCU single-chip microcomputer is converted into the work corresponding voltage reference value of upper limit threshold of output voltage of desired rectification filtering module of system analog signal and exports respectively the reference voltage input terminal C of voltage feedback loop to by D/A converter module, the work corresponding voltage reference value of upper limit threshold of output current of desired rectification filtering module of system is converted into to analog signal and exports respectively the reference voltage input terminal B of current feedback loop to by D/A converter module, the work corresponding voltage reference value of upper limit threshold of desired battery charge of system is converted into to analog signal and exports respectively the reference voltage input terminal D of charging current feedback control loop to by D/A converter module, each feedback control loop is under the effect of voltage reference signal, when the output current of rectification filtering module surpasses its upper limit threshold, current feedback loop can output feedback signal to the PWM controller, the PWM controller change its output pwm signal duty ratio so that make the output current of rectification filtering module be returned to it below upper limit threshold, when the output voltage of rectification filtering module surpasses its upper limit threshold, voltage feedback loop can output feedback signal to the PWM controller, the PWM controller change its output pwm signal duty ratio so that make the output current of rectification filtering module be returned to it below upper limit threshold, when the charging current of battery surpasses its upper limit threshold, the charging current feedback control loop can output feedback signal to the PWM controller, the PWM controller change its output pwm signal duty ratio so that make the output current of rectification filtering module descend, and then make the charging current of battery be returned to below upper limit threshold.
If the power of rectification filtering module output is greater than the low-voltage equipment power demand, to add battery charge power sum be the required electric current of low-voltage equipment while being less than the electric current of rectification filtering module output, and it is the electric current that battery and low-voltage equipment receive rectification filtering module output jointly that the electric current that the electric current that low-voltage equipment is accepted equals rectification filtering module output subtracts battery charge; If it is the electric current of rectification filtering module output output while being less than the required electric current of low-voltage equipment that the power of rectification filtering module output is less than the low-voltage equipment power demand, it is the electric current that low-voltage equipment is accepted rectification filtering module and battery output simultaneously that the output current that the electric current that low-voltage equipment is accepted equals rectification filtering module adds the battery discharge electric current.
The power supply system for automobile that technical scheme of the present invention is more traditional and method have significant advantage, are in particular in:
(1) the multiple collection to output voltage and electric current by voltage feedback loop, current feedback loop, charging current feedback control loop, at output current or voltage, surpass on predetermined threshold in limited time, the duty ratio that changes output pwm signal by the PWM controller changes the size of final output current or magnitude of voltage, thereby can guarantee that automobile-used low-voltage equipment need for electricity use can guarantee and the useful life of Vehicular battery.
(2) increased control module, because the MCU single-chip microcomputer has data storages and data are processed and the ability of data communication, thus the state of monitoring voltage electric current in real time, the running parameter of setting electric power system, cooperation integrated vehicle control tactics.
The accompanying drawing explanation
Fig. 1 is the structure chart of power supply system for automobile of the present invention.
Embodiment
Narrate the specific embodiment of the present invention below in conjunction with accompanying drawing; below in conjunction with accompanying drawing, the embodiment of the present invention is further described; below just exemplary about the description of embodiments of the present invention; the claimed theme be not meant to limit the present invention; the variation of other that also exist for embodiment described in the invention in the claim protection range, all belong to the theme that will protect required for the present invention.
As shown in Figure 1, this power supply system for automobile, comprise power supply, PWM controller, power model, transformer, rectification filtering module, also comprises current feedback loop, voltage feedback loop, charging current feedback control loop, control module; Power supply is connected to the input of power model, and power model is connected to the elementary E of transformer, and transformer secondary output F is connected to the output of rectification filtering module; Rectification module be connected to respectively low-voltage equipment and battery, the output, the battery that show as low-voltage equipment, rectification filtering module are connected in twos and form common node A, the output of PWM controller is connected to the control end of power switch pipe, electrical cable between the output of common node A and rectification filtering module is provided with the first current sensor, is provided with the second current sensor on the electrical cable between common node A and battery; The input that exports current feedback loop to of the first current sensor, the second current sensor exports the input that charging current is fed back electric loop to, the input of voltage feedback loop is connected with common node A, and the output of current feedback loop, voltage feedback loop, charging current feedback control loop is connected to respectively the input of PWM controller; Control module comprises MCU single-chip microcomputer, analog to digital converter, digital to analog converter; The first current sensor, the second current sensor also export respectively the input of analog to digital converter to, the input of analog to digital converter is connected to common electrical node A, the output of analog to digital converter exports the MCU single-chip microcomputer to, the MCU single-chip microcomputer is connected to the input of digital to analog converter, and the output of digital to analog converter is connected to respectively reference voltage input terminal B, the voltage feedback loop reference voltage input terminal C of current feedback loop, the reference voltage input terminal D of charging current feedback control loop.
Connected mode between each parts in the car electric power system is electrical connection.Power model consists of power switch pipe and bridge circuit, rectification filtering module consists of the current rectifying and wave filtering circuit structure, the current rectifying and wave filtering circuit structure of using is general current rectifying and wave filtering circuit structure, for example diode rectifier circuit adds the LC filter circuit, or other general current rectifying and wave filtering circuit structures.
Power supply output high-tension current is to power model, thereby PWM controller output pwm signal to power model driving power module is converted into high-voltage square-wave by the high-tension current of power supply output, high-voltage square-wave is converted into the low pressure square wave through transformer, the low pressure square wave is converted into low-voltage DC after rectification filtering module, and low-voltage DC is respectively the low-voltage equipment power supply, is the battery charging; The charging feedback control loop feeds back to the PWM controller by the charging current induced signal of battery, current feedback loop feeds back to the PWM controller by the current sensing signal of rectification filtering module output, and the voltage induced signal feedback that voltage feedback loop is exported rectification filtering module is to the PWM controller; Control module is respectively to charging current feedback control loop, current feedback loop, voltage feedback loop output voltage reference signal, and the charging current of output current, output voltage and the battery of rectification filtering module is gathered and detects, control module is carried out data communication by CAN bus and other mobile units simultaneously.The principle of control module acquisition testing and data communication is that the MCU single-chip microcomputer has the data storage and data are processed and the ability of data communication, the state of monitoring voltage electric current in real time, set the running parameter of electric power system, and communicate with other mobile units, thereby coordinate integrated vehicle control tactics.
The MCU single-chip microcomputer is converted into the work corresponding voltage reference value of upper limit threshold of output voltage of desired rectification filtering module of system analog signal and exports respectively the reference voltage input terminal C of voltage feedback loop to by D/A converter module, the work corresponding voltage reference value of upper limit threshold of output current of desired rectification filtering module of system is converted into to analog signal and exports respectively the reference voltage input terminal B of current feedback loop to by D/A converter module, the work corresponding voltage reference value of upper limit threshold of desired battery charge of system is converted into to analog signal and exports respectively the reference voltage input terminal D of charging current feedback control loop to by D/A converter module, each feedback control loop is under the effect of voltage reference signal, when the output current of rectification filtering module surpasses its upper limit threshold, current feedback loop can output feedback signal to the PWM controller, the PWM controller change its output pwm signal duty ratio so that make the output current of rectification filtering module be returned to it below upper limit threshold, when the output voltage of rectification filtering module surpasses its upper limit threshold, voltage feedback loop can output feedback signal to the PWM controller, the PWM controller change its output pwm signal duty ratio so that make the output current of rectification filtering module be returned to it below upper limit threshold, when the charging current of battery surpasses its upper limit threshold, the charging current feedback control loop can output feedback signal to the PWM controller, the PWM controller change its output pwm signal duty ratio so that make the output current of rectification filtering module descend, and then make the charging current of battery be returned to below upper limit threshold.Thereby the PWM controller is controlled the change of pwm signal duty ratio, the PWM controller increases or reduces the duty ratio of pwm signal, after transformer and rectification filtering module, the voltage of output also changes thereupon, electric current and then the change of output after the voltage of output changes.
If the power of rectification filtering module output is greater than the low-voltage equipment power demand, to add battery charge power sum be the required electric current of low-voltage equipment while being less than the electric current of rectification filtering module output, and it is the electric current that battery and low-voltage equipment receive rectification filtering module output jointly that the electric current that the electric current that low-voltage equipment is accepted equals rectification filtering module output subtracts battery charge; If it is the electric current of rectification filtering module output output while being less than the required electric current of low-voltage equipment that the power of rectification filtering module output is less than the low-voltage equipment power demand, it is the electric current that low-voltage equipment is accepted rectification filtering module and battery output simultaneously that the output current that the electric current that low-voltage equipment is accepted equals rectification filtering module adds the battery discharge electric current.
Embodiments of the invention are example embodiment of the present invention; should be understood to is certain demonstrative example wherein in the protection range of claims of the present invention; there is the directiveness effect that those skilled in the art is realized to corresponding technical scheme, but not limitation of the invention.