A kind of hybrid power system used for electric vehicle
Technical field
The present invention relates to a kind of elec. vehicle composite power source energy storing device, use electrokinetic cell, super capacitor and engine-generator set to form composite power source, realize the reasonable distribution of energy by composite power source controller.
Background technology
Energy shock, environmental pollution have caused worldwide automobile dynamic system revolution.For conservation of nature environment, save non-renewable energy resources, improve the energy and use structure, research and development new forms of energy power vehicle is imperative.Under the promotion of pure electric automobile, hybrid vehicle research climax, Global Auto industry is just marched toward epoch of " energy-conservation, reduce discharging ".In view of the current situation of current vehicle mounted dynamic battery, the practical of pure electric automobile is had got long long way to go, vehicle-mounted power closed-center system will be an indispensable part for following clean energy vehicle, and the quality of its performance directly affects the performance figure of car load and the About Developing Trend of Future New Energy Source automobile.
Vehicle power needs advanced, electric energy storage system compact conformation, high-energy-density that high-energy and high-power is provided, and the characteristic of the closed-center system of single type all cannot meet separately this requirement under the condition of economy at present.The vehicle mounted dynamic battery using at present and super capacitor, in the continual mileage performance of car load, all can not match in excellence or beauty with traditional fuel-engined vehicle.Comparatively speaking, electrokinetic cell specific energy is larger for electrokinetic cell and super capacitor, and specific power deficiency, super capacitor specific power is larger, but specific energy deficiency.
Summary of the invention
To the object of the invention is in order addressing the above problem, to propose a kind of hybrid power system used for electric vehicle, there is stored energy amount, specific power is large, the advantage that the life-span is long.
Hybrid power system of the present invention comprises electrokinetic cell, super capacitor and two-way DC/DC changer thereof, engine-generator set and two-way AC/DC changer, protective resistance and DC/DC changer thereof, hybrid power system controller, and hybrid power system bus composition.
Engine-generator set is connected on bus by two-way AC/DC changer, and super capacitor is connected on bus by two-way DC/DC changer, and protective resistance is connected on bus by DC/DC changer, and electrokinetic cell is directly connected on bus.
In the present invention, electrokinetic cell, as main energy-storage units, is connected with bus all the time, provides electric current or from bus Absorption Current to bus; Super capacitor, as pulse power supply, for bus provides peak power or absorbs braking energy from bus, reduces the fluctuation of bus voltage, makes electrokinetic cell mode of operation stable gently, extends the electrokinetic cell life-span; Engine-generator set is energy-storage units in support, in the time that electrokinetic cell electric weight is not enough, starts, and provides energy to bus, can be power battery charging simultaneously, can effectively extend the continual mileage of elec. vehicle.
Hybrid power system can effectively absorb by electrokinetic cell and super capacitor the braking energy of elec. vehicle; in the time that braking energy exceeds current electrokinetic cell and super capacitor absorption power; hybrid power system controller is by controlling protective resistance DC/DC changer starting protection resistance; absorb unnecessary braking energy, to protect hybrid power system.
In the time of needs start the engine-generator set, engine power generation unit is converted to the direct current (DC) on hybrid power system bus by AC/DC changer the alternating current that can make machine operation, and now motor, in electric model, drives engine starting; After engine starting, drive motor is operated in power generation mode, carries electric current by AC/DC changer to hybrid power system bus.
The invention has the advantages that:
It is fast that super capacitor of the present invention discharges and recharges speed, can bear hybrid power system instantaneous peak value and discharge and recharge electric charge, especially be suitably in frequent starting and the braking of vehicle in urban traffic situation, make the charging and discharging currents of electrokinetic cell mild, the life-span of having improved electrokinetic cell simultaneously.Meanwhile, engine-generator set can effectively improve the capacity of power-supply system, increases the continual mileage of elec. vehicle.
Brief description of the drawings
Fig. 1 is system schematic of the present invention.
In figure:
Electrokinetic cell 1 |
Ultracapacitor 2 |
The one DC/DC changer 3 |
Engine-generator set 4 |
AC/DC changer 5 |
Protective resistance 6 |
The 2nd DC/DC changer 7 |
Power-supply system bus 8 |
Hybrid power system controller 9 |
Detailed description of the invention
Below in conjunction with drawings and Examples, the present invention is described in further detail.
The present invention is a kind of hybrid power system used for electric vehicle; as shown in Figure 1, comprise electrokinetic cell 1, ultracapacitor 2, a DC/DC changer 3, engine-generator set 4, AC/DC changer 5, protective resistance 6, the 2nd DC/DC changer 7, power-supply system bus 8, hybrid power system controller 9.
Electrokinetic cell 1 is by 113 ferric phosphate lithium cell monomer series-connected compositions, and electrokinetic cell specification is 361V, 110Ah, and battery cell can be selected the LiFePO4 vanadium electrokinetic cell of 110Ah, 3.2V that Guangdong Zhicheng Guanjun Group Co.,Ltd produces.
Ultracapacitor 2 is by 134 super capacitor monomer series-connected compositions, and super capacitor specification is 361V, 22F, 2.7V, 3000F super capacitor monomer that super capacitor monomer can select Maxwell company of the U.S. to produce.
Engine-generator set 4 comprises driving engine, gearbox, alternating current generator, and wherein, driving engine adopts gasoline engine or diesel engine; Electrical generator is switched reluctance machines or permagnetic synchronous motor, and driving engine connects alternating current generator by gearbox, and alternating current generator connects AC/DC changer 5.
Power-supply system bus 8 connects load, engine-generator set 4 is connected on power-supply system bus 8 by AC/DC changer 5, electrokinetic cell 1 is directly connected on power-supply system bus 8, ultracapacitor 2 is connected on power-supply system bus 8 by a DC/DC changer 3, protective resistance logical 6 is crossed the 2nd DC/DC changer 7 and is connected on power-supply system bus 8, hybrid power system controller 9 is exported AC/DC changer 5, the driving signal of the one DC/DC changer 3 and the 2nd DC/DC changer 7, realize engine-generator set 4, the object that ultracapacitor 2 and protective resistance 6 are controlled.
After elec. vehicle starts, first hybrid power system controller 9 judges the electric weight of electrokinetic cell 1, if it is greater than threshold value (as 20%), and start the engine-generator set 4 not, on the contrary start.Judge the state-of-charge of super capacitor 2 thereafter, current during lower than threshold value (as 50%), by controlling a DC/DC changer 3, hybrid power system is preferentially charged to super capacitor 2.When vehicle operating, provide average power by electrokinetic cell 1 for vehicle, in the time of the anxious acceleration of vehicle or climbing, the power-supply system demand power that composite power source controller 9 obtains is larger, now composite power source controller 9 is according to the state-of-charge of super capacitor 2, if it is greater than threshold value (as 20%), start super capacitor 2 by controlling a DC/DC changer 3, make super capacitor 2 provide peak power for vehicle.
In the time that composite power source controller 9 detects that electrokinetic cell 1 electric weight is less than threshold value (as 20%), start the engine generator set: composite power source controller 9 is by controlling AC/DC changer 5, direct current (DC) on hybrid power system bus 8 is converted to the alternating current that can make machine operation, now motor, in electric model, drives engine starting.After engine starting, drive motor is operated in power generation mode, carry electric current by AC/DC changer 5 to hybrid power system bus 8, for electrokinetic cell 1 charges, until electrokinetic cell 1 electric weight is greater than thresholding system (as the 80%) generator set 4 that kills engine.
In the time that elec. vehicle produces braking energy; composite power source controller 9 is according to the state-of-charge of super capacitor 2 and electrokinetic cell 1; being preferably super capacitor 2 charges; in the time that braking energy is greater than the absorption power of current super capacitor 2 and electrokinetic cell 1; by controlling protective resistance DC/DC changer 7 starting protection resistance 6; make protective resistance 6 absorb a part of braking energy, to protect hybrid power system.