Vehicle dual-voltage energy recovery system and control method thereofThe technical field is as follows:
the invention belongs to the technical field of vehicle energy recovery, and relates to a vehicle dual-voltage energy recovery system and a control method thereof.
Background art:
the existing passenger vehicle generally uses a storage battery, 12V voltage system. Only a 12V voltage system is adopted for power supply, and the defects of large energy loss and low energy utilization rate are overcome; when the vehicle brakes, the storage battery has low capacity of receiving transient energy and cannot bear heavy current and high voltage frequent impact, so that the recoverable transient potential energy is reduced. In addition, when the electric quantity of the vehicle storage battery is low or the vehicle storage battery is in failure, a vehicle user cannot keep the electric loads working in emergency states such as a danger alarm lamp and a vehicle headlamp for a long time.
The invention content is as follows:
the invention aims to solve the technical problem of providing a vehicle dual-voltage energy recovery system and a control method thereof.
In order to solve the technical problem, the vehicle dual-voltage energy recovery system comprises an electric energy control unit, an engine controller, an engine, a super capacitor, a generator, a storage battery, a starter, an electric load and a direct current-direct current converter; the electric energy control unit is electrically connected with the engine controller, the super capacitor, the generator, the storage battery and the direct current-direct current converter; the engine controller is electrically connected with the control end of the engine and the control end of the starter; the output ends of the super capacitor and the generator are connected between the first node and a power ground, and the storage battery, the power supply end of the starter and the power load are connected between the second node and the power ground; the DC-DC converter is connected between the first node and the second node; the power output part of the starter is connected with the power input part of the engine through a mechanical structure; the power output part of the engine is connected with the power input part of the generator through a mechanical structure; the generator can output direct current with low voltage V or direct current with high voltage V' under the control of the electric energy control unit.
The control method of the vehicle dual-voltage energy recovery system comprises the following working conditions:
when the engine state signal collected by the electric energy control unit represents that the vehicle is in a braking and decelerating working condition, the engine drives the generator to work, and high voltage V' is output to supplement electric quantity for the super capacitor; meanwhile, the direct current-direct current converter converts the high voltage V' stored by the super capacitor into the low voltage V, and the low voltage V is supplied to the storage battery and the electric load; when the engine state signal acquired by the electric energy control unit represents the working condition that the starter starts the engine, the electric energy control unit controls the generator not to generate electricity; the DC-DC converter is switched on to work, the high voltage V' of the super capacitor is converted into the low voltage V, and the auxiliary storage battery supplies power to the starter.
Further, the control method of the vehicle dual-voltage energy recovery system further comprises the following working conditions: after the engine is started, when the engine state signal acquired by the electric energy control unit represents that the vehicle is in an acceleration state or an idling stop state, the generator is controlled not to generate electricity; at the moment, the DC-DC converter converts the high voltage V' stored by the super capacitor into the low voltage V, and the low voltage V is supplied to the storage battery and the electric load.
Further, the control method of the vehicle dual-voltage energy recovery system further comprises the following working conditions: when the engine state signal collected by the electric energy control unit represents that the vehicle is in normal running and the electric quantity of the super capacitor is above the lower limit, the super capacitor is used for supplying power to the storage battery and the power utilization load, and at the moment, the direct current converter is controlled to convert the high voltage V' of the super capacitor into the low voltage V which is supplied to the storage battery and the power utilization load for supplying power.
Further, the control method of the vehicle dual-voltage energy recovery system further comprises the following working conditions:
when the engine state signal acquired by the electric energy control unit represents that the vehicle normally runs and the electric quantity of the storage battery reaches the electric quantity control lower limit E1, the electric energy control unit controls the generator to generate electricity and outputs high voltage V' to supplement the electric quantity for the super capacitor; meanwhile, the direct current-direct current converter converts the high voltage V' stored by the super capacitor into the low voltage V, and the low voltage V is supplied to the storage battery and the electric load; when the electric quantity of the storage battery reaches the upper limit electric quantity E2, the electric energy control unit cuts off the direct current converter, and the storage battery provides high and low voltage V for the electric load.
Further, the control method of the vehicle dual-voltage energy recovery system further comprises the following working conditions:
when the storage battery state signal acquired by the electric energy control unit represents that the storage battery has a fault after the vehicle is started, the electric energy control unit controls the direct current-direct current converter to convert the 24V direct current of the super capacitor into 12V direct current, and the electric load supplies power; meanwhile, the fault information of the storage battery is sent to a vehicle-mounted display terminal to prompt a vehicle user; when the storage battery state signal acquired by the electric energy control unit represents that the vehicle is not started and the storage battery has a fault, the vehicle cannot be started, and at the moment, the electric energy control unit controls the direct current converter to convert the 24V direct current of the super capacitor into the 12V direct current to supply power for electric loads in emergency states such as a danger alarm lamp, a vehicle headlamp and the like, so that the fault that the vehicle cannot be started normally after a single power supply of the vehicle is damaged can be solved.
Further, the control method of the vehicle dual-voltage energy recovery system further comprises the following working conditions:
when the super capacitor state signal collected by the electric energy control unit represents that the super capacitor fails, the electric energy control unit controls the generator to generate electricity, outputs low voltage V, and controls the direct current-direct current converter to be switched on, so that the generator provides the low voltage V for the storage battery and the power load.
Further, the control method of the vehicle dual-voltage energy recovery system further comprises the following working conditions:
when the super capacitor state signal collected by the electric energy control unit represents that the electric quantity of the super capacitor is exhausted, the electric energy control unit cuts off the direct current-direct current converter, and the storage battery provides low voltage V for the electric load.
Has the advantages that:
the invention introduces a dual-voltage energy recovery system and a control method. The electric energy control unit is used for acquiring state signals of the storage battery, the super capacitor and the engine controller, controlling the switch of the direct current-direct current converter to be opened or closed, and controlling the generator to generate electricity. When the braking working condition is detected, the engine drives the generator to work to charge the super capacitor, and the super capacitor is used for supplying power to the storage battery and the electric load, so that the braking energy of the engine is converted into electric energy, and the energy utilization rate is improved. When the starter is detected to start the engine, the super capacitor is used for assisting the storage battery to supply power to the starter, so that the influence of the voltage reduction of the storage battery on the electrical load when the engine is started can be reduced. When the braking deceleration of the vehicle is detected, the braking energy is recovered by using the generator and the super capacitor. When the vehicle accelerates or stops at idle speed, the super capacitor is used for supplying power to the storage battery and the electric load through the high-voltage to low-voltage direct current-direct current converter, so that the torque consumption of the generator is avoided when the vehicle accelerates or stops at idle speed, the acceleration capacity of the vehicle is improved, and fuel is saved. When the vehicle normally runs, the super capacitor is preferentially used to supply power to the storage battery and the power load through the high-voltage-to-low-voltage direct current-direct current converter according to the electric quantity condition of the super capacitor, and the storage battery is reused to supply power to the power load after the electric quantity of the super capacitor is exhausted, so that the advantages of long cycle life and short charging time of the super capacitor are fully utilized, and the service life of the storage battery is prolonged. The generator adopts wide voltage to control V-V ', outputs high voltage V ' during energy recovery, outputs low voltage V when the super capacitor fails, uses high voltage V ' during work of the super capacitor, can reduce energy loss under the same power by using high voltage, and improves energy utilization rate.
Description of the drawings:
the invention is described in further detail below with reference to the following figures and detailed description:
FIG. 1 is a schematic diagram of a dual voltage energy recovery system of the present invention;
in the figure: 1, an electric energy control unit; 2 an engine controller; 3, an engine; 4, a super capacitor; 5, a generator; 6, a storage battery; 7, a starter; 8, using an electric load; 9 a dc-dc converter; 11. a first node; 12. and a second node.
The specific implementation mode is as follows:
in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
As shown in fig. 1, the vehicle dual-voltage energy recovery system of the present invention includes an electricenergy control unit 1, anengine controller 2, anengine 3, asuper capacitor 4, agenerator 5, abattery 6, astarter 7, anelectric load 8, and a dc-dc converter 9. The electric energy control unit is a control unit of the system and is electrically connected with theengine controller 2, thesuper capacitor 4, thegenerator 5, thestorage battery 6 and the direct current-direct current converter 9; theengine controller 2 is electrically connected with the control end of theengine 3 and the control end of thestarter 7; the output ends of thesuper capacitor 4 and thegenerator 5 are connected between afirst node 11 and a power ground, and thestorage battery 6, the power supply end of thestarter 7 and thepower load 8 are connected between asecond node 12 and the power ground; the dc-dc converter 9 is connected between afirst node 11 and asecond node 12; the power output part of thestarter 7 is connected with the power input part of theengine 3 through a mechanical structure. The power output part of the engine is connected with the power input part of the generator through a mechanical structure (used for recovering braking energy). Thegenerator 5 can output 12V low-voltage dc or 24V high-voltage dc under the control of thepower control unit 1.
The electricenergy control unit 1 collects an engine state signal output by an engine controller, controls the generator to selectively output 12V or 24V direct current, receives a generator voltage signal and judges whether the output is 24V direct current, receives a storage battery state signal (comprising an electric quantity state signal and a state signal whether a fault occurs), receives a super capacitor state signal (comprising an electric quantity state signal and a fault signal), and controls the direct current-direct current converter to switch between 12V and 24V and to be switched on as a switch.
The engine controller is used for acquiring an engine state signal, sending the engine state signal to the electricenergy control unit 1 and controlling the starter to start the engine.
The generator is controlled to be 12-24V by adopting wide voltage, the generator is used for generating power by adopting 24V voltage during energy recovery, the generator outputs 12V direct current when the super capacitor breaks down, the super capacitor works to use 24V direct current, and the energy loss can be reduced and the energy utilization rate can be improved by using high voltage under the same power.
Example 1
The vehicle double-voltage energy recovery control method comprises the following working conditions;
when the electricenergy control unit 1 collects an engine state signal of theengine controller 2, the state of theengine 3 is judged, and whether the direct current-direct current converter 9 works or not is controlled according to the state signals of thesuper capacitor 4, thestorage battery 6 and thegenerator 5.
When the engine state signal acquired by the electricenergy control unit 1 represents that the vehicle is in a braking working condition, the electric energy control unit controls the generator to generate electricity, the generator is driven by the engine to work, 24V voltage is output, and the super capacitor is charged; meanwhile, the direct current-direct current converter converts the 24V direct current stored in the super capacitor into 12V direct current to be supplied to the storage battery and the electric load.
When the engine state signal collected by the electricenergy control unit 1 represents the process of starting the engine by the starter, the electric energy control unit controls the generator not to generate electricity; at the moment, the starter is powered by the storage battery, so that the starting resistance moment of the engine can be reduced; and at the moment, the direct current-direct current converter is switched on to work, 24V direct current of thesuper capacitor 4 is converted into 12V direct current, and the auxiliary storage battery supplies power for the starter so as to reduce the influence of voltage reduction of the storage battery on an electrical load when the engine is started.
Example 2
The vehicle dual-voltage energy recovery control method further comprises the following working conditions;
after the engine is started, when the engine state signal acquired by the electricenergy control unit 1 represents that the vehicle is in an acceleration state or an idling stop state, the generator is controlled not to generate electricity; at the moment, the direct current-direct current converter converts the 24V direct current stored by the super capacitor into 12V direct current to be supplied to the storage battery and the electric load, so that the torque consumption of the generator can be avoided when the vehicle accelerates and idles, the acceleration capacity of the vehicle is improved, and fuel is saved.
Example 3
The vehicle dual-voltage energy recovery control method further comprises the following working conditions;
when the engine state signal acquired by the electricenergy control unit 1 represents that the vehicle is in normal running and the electric quantity of the super capacitor is above the lower limit, the super capacitor is preferentially used for supplying power to the storage battery and the electric load, and at the moment, the direct current-direct current converter is controlled to convert the 24V direct current of the super capacitor into 12V direct current to supply power to the storage battery and the electric load.
Example 4
The vehicle dual-voltage energy recovery control method further comprises the following working conditions;
when the engine state signal acquired by the electricenergy control unit 1 represents that the vehicle normally runs and the electric quantity of the storage battery reaches the electric quantity control lower limit E1, the electric energy control unit controls the generator to generate electricity and output 24V direct current to supplement the electric quantity for the super capacitor; meanwhile, the direct current-direct current converter converts the 24V direct current stored in the super capacitor into 12V direct current to be supplied to the storage battery and the electric load. When the electric quantity of the storage battery reaches the upper limit electric quantity E2, the electric energy control unit cuts off the direct current converter, the storage battery provides 12V direct current for the electric load, in the process, the electric quantity of the storage battery is reduced from approaching the upper limit electric quantity E2 to the electric quantity control lower limit E1, and capacity space is prepared for the energy stored in the super capacitor.
Example 5
The vehicle dual-voltage energy recovery control method further comprises the following working conditions:
when the storage battery state signal acquired by the electricenergy control unit 1 represents that the storage battery has a fault after the vehicle is started, the electric energy control unit controls the direct current-direct current converter to convert the 24V direct current of the super capacitor into 12V direct current, and the electric load supplies power; meanwhile, the fault information of the storage battery is sent to a vehicle-mounted display terminal to prompt a vehicle user; when the storage battery state signal acquired by the electricenergy control unit 1 represents that the vehicle is not started and the storage battery has a fault, the vehicle cannot be started, and at the moment, the electric energy control unit controls the direct current converter to convert the 24V direct current of the super capacitor into 12V direct current so as to supply power to electric loads in emergency states such as a danger alarm lamp, a vehicle headlamp and the like.
Example 6
The vehicle dual-voltage energy recovery control method further comprises the following working conditions;
when the super capacitor state signal acquired by the electricenergy control unit 1 represents that the super capacitor fails, the electric energy control unit controls the generator to generate power, 12V direct current is output, and meanwhile, the direct current-direct current converter is controlled to be switched on, and at the moment, the direct current-direct current converter is only used as a switch and does not convert high voltage into low voltage. At this time, the generator provides 12V direct current for the storage battery and the electric load, and the energy recovery function cannot be realized.
Example 8
The vehicle dual-voltage energy recovery control method further comprises the following working conditions;
when the super capacitor state signal collected by the electricenergy control unit 1 represents that the electric quantity of the super capacitor is exhausted, the electric energy control unit cuts off the direct current converter, and at the moment, the storage battery provides 12V direct current for the electric load.