CN103010044B - A kind of electric power system of hybrid vehicle - Google Patents

Abstract

The invention provides a power supply system of a hybrid electric vehicle, which is connected with a motor drive system driving the vehicle. The power supply system includes: a fuel cell, a hydrogen supply system, fuel cell accessories, an auxiliary power source, and a power converter; the power supply The system also includes: a control element connected to the power converter and connected to the fuel cell and the motor drive system when the power converter is not working; A contactor, the first connection end is connected to the fuel cell, the second connection end is connected to the power converter; a diode used to control the fuel cell to supply power to the fuel cell accessories, the anode of the diode is connected to the The fuel cell is connected, and the cathode of the diode is connected with the fuel cell accessory. The invention can solve the problems of high cost and large volume of the power converter of the existing power supply system and low operating efficiency of the fuel cell system.

Description

A power supply system for a hybrid vehicle

technical field

The invention relates to the technical field of fuel cell vehicles, in particular to a power supply system of a hybrid vehicle.

Background technique

A hybrid vehicle refers to a vehicle that has at least two power sources and uses one or more of them to provide part or all of the power. However, in real life at present, most hybrid vehicles use traditional internal combustion engines and electric motors as power sources, and drive the vehicles through the mixed use of two systems of heat and electricity. The internal combustion engines used are both diesel and gasoline, so traditional gasoline or diesel can be used, and some engines have been modified to use other alternative fuels, such as compressed natural gas, propane and ethanol fuel.

There are many kinds of vehicle power sources: batteries, supercapacitors, fuel cells, solar cells, generator sets for diesel locomotives. Currently, hybrid vehicles generally refer to cars with generators for diesel locomotives and batteries. Fuel cell vehicles use hydrogen as energy, and the fuel cell system converts hydrogen energy into electrical energy, and then drives the vehicle through the motor drive system. Because fuel cells have problems in terms of voltage characteristics and dynamic response of power output, it usually requires auxiliary power sources to supplement and improve them in terms of power output capabilities to form a fuel cell hybrid power system. Due to the soft output characteristics of the fuel cell, an indirect fuel cell hybrid system structure is generally adopted at present, that is, the fuel cell and the auxiliary power source are coupled through a power converter to control the power flow from the fuel cell to the motor drive system and the auxiliary power source.

Different from traditional automobile engines starting with 12V batteries, fuel cell accessory systems generally use high-voltage power supply, so they are generally powered by auxiliary power sources before starting successfully, which will inevitably lead to the following problems:

1. The power converter requires relatively large power (including the power of the fuel cell accessory system), which depends on the power output of the fuel cell, so it will inevitably lead to an increase in system cost and an increase in the size of the power converter.

2. The efficiency of the fuel cell system is relatively low because the power supply of the fuel cell accessory system passes through the power converter.

Therefore, it is currently necessary to transform the power supply system in the prior art to solve the above problems.

Contents of the invention

In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a power supply system for hybrid electric vehicles, which is used to solve the problems of high cost, large volume and low operating efficiency of the fuel cell system in the existing power supply system. .

In order to achieve the above purpose and other related purposes, the present invention provides a power supply system for a hybrid electric vehicle, which is connected to a motor drive system that drives the vehicle. The power supply system includes: a fuel cell, connected to the motor drive system, for the The motor drive system is powered; the hydrogen supply system is connected to the fuel cell and provides the hydrogen energy required for the fuel cell to generate electric energy; the fuel cell accessory is connected to the fuel cell and provides the fuel cell for starting and stop providing support; the auxiliary power source is respectively connected to the motor drive system and the fuel cell accessory, and supplies power to the motor drive system and the fuel cell accessory; a power converter is connected between the fuel cell and the motor drive system, At the same time, it is also connected with the auxiliary power source for coupling the fuel cell and the auxiliary power source, and controlling the fuel cell and the auxiliary power source to supply power for the motor drive system; the control element is connected with the power converter Connected, when the power converter is not working, connect the fuel cell and the motor drive system; the contactor, connected between the fuel cell and the power converter, has a first connection end and a second Connecting end, the first connecting end is connected to the fuel cell, the second connecting end is connected to the power converter; a diode is used to control the fuel cell to supply power to the fuel cell accessory, and the diode The anode of the diode is connected to the fuel cell, and the cathode of the diode is connected to the fuel cell accessory.

Optionally, the control element is a power tube.

Optionally, the control element is a relay.

Optionally, the power converter is a DC-DC converter.

Optionally, the power converter includes a diode for controlling the fuel cell to supply power to the motor drive system, and the two ends of the control element are connected to the two ends of the diode.

Optionally, the fuel cell accessories include: an air compressor system and a water pump.

Optionally, the auxiliary power source is a power storage battery, a supercapacitor, or a solar battery.

As mentioned above, a power supply system for a hybrid vehicle of the present invention has the following beneficial effects:

1. In the present invention, a control element is arranged on the power converter between the fuel cell and the auxiliary power source, and a relay and a diode are arranged on the line between the power converter and the fuel cell, so that the fuel cell can be used without the fuel cell. In the case of starting, the auxiliary power source supplies power to the fuel cell accessory, thereby solving the problems of high cost and large volume of the power converter in the existing power supply system and low operating efficiency of the fuel cell system.

2. The power supply system of the present invention can smoothly switch the power supply voltage to the motor drive system through the power converter control without affecting the function and performance of the original power converter while ensuring the smooth start of the fuel cell.

3. The power supply system of the present invention has simple structure, low cost and convenient control.

Description of drawings

FIG. 1 shows a schematic structural diagram of a power supply system of a hybrid electric vehicle according to the present invention.

FIG. 2 is a schematic diagram showing a preferred structure of a power supply system of a hybrid electric vehicle according to the present invention.

Component designation description

1 Power supply system

11 Fuel cells

12 Hydrogen supply system

13 Fuel Cell Accessories

131 Air compressor system

132 water pump

14 auxiliary power source

15 power converter

16 control elements

17 contactor

18 diodes

19 charger

detailed description

The implementation of the present invention will be illustrated by specific specific examples below, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

Please refer to Figure 1 to Figure 2. It should be noted that the structures, proportions, sizes, etc. shown in the drawings attached to this specification are only used to match the content disclosed in the specification, for those who are familiar with this technology to understand and read, and are not used to limit the implementation of the present invention. Limiting conditions, so there is no technical substantive meaning, any modification of structure, change of proportional relationship or adjustment of size, without affecting the effect and purpose of the present invention, should still fall within the scope of the present invention. The disclosed technical content must be within the scope covered. At the same time, terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit this specification. The practicable scope of the invention and the change or adjustment of its relative relationship shall also be regarded as the practicable scope of the present invention without any substantial change in the technical content.

The fuel cell accessory system generally uses high voltage power supply, so it is generally powered by the auxiliary power source before the startup is successful, so the power converter needs a relatively large power (including the power of the fuel cell accessory), which depends on the power output of the fuel cell, so it will inevitably bring the system An increase in cost and an increase in the size of the power converter. At the same time, since the power supply of the fuel cell accessories passes through the power converter, the efficiency of the fuel cell system is relatively low.

In view of this, the present invention provides a power supply system for a hybrid electric vehicle, which is used to solve the problems of high cost, large volume and low operating efficiency of the fuel cell system in the existing power supply system. The principle and implementation of the power supply system of a hybrid electric vehicle of the present invention will be described in detail below, so that those skilled in the art can understand the power supply system of a hybrid electric vehicle of the present invention without creative work.

Please refer to FIG. 1 and FIG. 2 , which are a schematic structural diagram and a preferred structural schematic diagram of a power supply system of a hybrid electric vehicle according to the present invention. As shown in Figure 1 and Figure 2, the present invention provides a power supply system for a hybrid electric vehicle, which is connected to the motor drive system that drives the vehicle. The power supply system 1 includes: a fuel cell 11, a hydrogen supply system 12, and fuel cell accessories 13. Auxiliary power source 14, power converter 15, control element 16, contactor 17, and diode 18.

The fuel cell 11 is connected to the motor drive system and supplies power to the motor drive system. In this embodiment, the motor drive system includes a motor controller, a motor, a reducer and the like connected in sequence. In the present invention, the fuel cell vehicle uses hydrogen energy as an energy source, and the fuel cell 11 converts the hydrogen energy into electric energy, and then drives the vehicle to run through a motor drive system. Therefore, in the present invention, a hydrogen supply system 12 connected to the fuel cell 11 and providing the fuel cell 11 with hydrogen energy required to generate electric energy is also included.

The fuel cell accessory 13 is connected with the fuel cell 11 and the auxiliary power source 14 to provide support for the start and stop of the fuel cell 11 . Specifically, in this embodiment, the fuel cell accessory 13 includes but not limited to: an air compressor system 131 and a water pump 132 .

In this embodiment, only the air compressor system is directly powered by the fuel cell after being started, and the water pump 132 is directly powered by the auxiliary power source. In the present invention, before the fuel cell is started, the air compressor system requires power from an auxiliary power source.

Since the fuel cell 11 has problems in terms of voltage characteristics and dynamic response of power output, it usually needs auxiliary power source 14 to supplement and improve it in terms of power output capacity, so as to constitute a fuel cell hybrid power system. The auxiliary power source 14 is respectively connected to the motor drive system and the fuel cell accessory 13 to provide power for the motor drive system and the fuel cell accessory 13 . Specifically, the auxiliary power source 14 may be, but not limited to, a power storage battery, a supercapacitor, or a solar battery. When the auxiliary power source 14 is a rechargeable battery, the rechargeable power battery is also connected to a charger 19 through which the battery is charged.

The power converter 15 is connected between the fuel cell 11 and the motor drive system, and is also connected to the auxiliary power source 14, for coupling the fuel cell 11 and the auxiliary power source 14, and controlling the fuel cell 11 And the auxiliary power source 14 supplies power to the motor drive system.

In this embodiment, the power converter 15 is a DC-DC converter. Specifically, the power converter 15 includes: an inductance coil connected to the fuel cell 11; a first diode that controls the fuel cell 11 to supply power to the motor drive system, and the cathode of the first diode is connected to the The motor drive system is connected, the anode of the first diode is connected to the inductance coil; a transistor and a second diode are connected in parallel, and a common end of the transistor and the second diode is connected to Between the inductance coil and the anode of the first diode, the other common end of the transistor and the second diode is connected to the line between the fuel cell 11 and the motor drive system; one end is connected to the first two The cathode of the pole tube, and the other end is connected to the capacitor on the line between the fuel cell 11 and the motor drive system.

In order to supply power to the fuel cell accessory 13 from the auxiliary power source 14 when the fuel cell 11 is not started, and to ensure the smooth start of the fuel cell 11, the power converter 15 can be used to control the smooth switching of the power supply to the motor drive system. voltage without affecting the function and performance of the original power converter 15, so in the present invention, a control element 16 is set on the power converter 15, connected between the fuel cell 11 and the power converter 15 A diode 18 and a contactor 17 are arranged in between. The connection and function of the above-mentioned control element 16, diode 18 and contactor 17 will be described in detail below.

The control element 16 is connected to the power converter 15 , specifically, both ends of the control element 16 are connected to both ends of the first diode in the power converter 15 . The function of the control element 16 is to connect (ie conduct) when the power converter 15 is not working. Since the power converter 15 is used to couple the fuel cell 11 and the auxiliary power source 14, the fuel cell 11 and the auxiliary power source 14 are controlled to supply power to the motor drive system. When the fuel cell 11 is not turned on, the power converter 15 does not work. At this time, the line between the fuel cell 11 and the motor drive system is equivalent to disconnection. It can be seen from FIG. 1 that at this time, the The auxiliary power source 14 cannot be connected with the fuel cell accessory 13, so it cannot supply power for the fuel cell accessory 13, so a control element 16 is added, and the control element 16 is equivalent to a switch. When working, the auxiliary power source 14 can be used to supply power to the fuel cell accessory 13 .

Specifically, the control element 16 is an element that functions as a switch such as a power tube or a relay. In this embodiment, the control element 16 is a power tube.

The contactor 17 has a first connection end and a second connection end, and is connected between the fuel cell 11 and the power converter 15 . Specifically, the first connection end is connected to the fuel cell 11 , and the second connection end is connected to the inductance coil in the power converter 15 .

The diode 18 is used to control the fuel cell 11 to supply power to the fuel cell accessory 13, the anode of the diode 18 is connected to the fuel cell 11, and the cathode of the diode 18 is connected to the fuel cell accessory 13 . Specifically, the cathode of the diode 18 is connected to the line between the contactor 17 and the inductance coil.

In order for those skilled in the art to further understand the principle and implementation of the present invention, the use of the power supply system of the hybrid electric vehicle added with the above-mentioned control element 16, diode 18 and contactor 17 will be described in detail below.

When the fuel cell 11 starts, the power converter 15 does not work, the contactor 17 is opened, the power tube is opened, and the fuel cell accessory 13 (in this embodiment, the air compressor system 131) supplies power through the auxiliary power source 14. At this time, the fuel cell The voltage in 11 gradually builds up, and the diode 18 is turned off in reverse; when the fuel cell 11 is started successfully, the power tube is turned off, the diode 18 is forward-conducting, and the fuel cell accessory 13 is self-powered by the fuel cell 11. At this time, the contactor 17 is closed, and the power supply The inverter 15 can perform power distribution between the fuel cell 11 and the auxiliary power source 14 in a normal mode.

When the fuel cell 11 needs to be shut down, the power converter 15 stops working, the power tube is turned on, the diode 18 is turned off in reverse, and the fuel cell accessory (in this embodiment, the air compressor system 131) 13 supplies power through the auxiliary power source 14, and then The purging and cooling of the fuel cell 11 can be accomplished by some purging and cooling devices until the fuel cell 11 is shut down.

In summary, a power supply system for a hybrid electric vehicle of the present invention has achieved the following beneficial effects:

1. In the present invention, a control element is arranged on the power converter between the fuel cell and the auxiliary power source, and a relay and a diode are arranged on the line between the power converter and the fuel cell, so that the fuel cell can be used without the fuel cell. In the case of starting, the auxiliary power source supplies power to the fuel cell accessory, thereby solving the problems of high cost and large volume of the power converter in the existing power supply system and low operating efficiency of the fuel cell system.

2. The power supply system of the present invention can smoothly switch the power supply voltage to the motor drive system through the power converter control without affecting the function and performance of the original power converter while ensuring the smooth start of the fuel cell.

3. The power supply system of the present invention has simple structure, low cost and convenient control.

Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (6)

1. A power supply system of a hybrid electric vehicle, which is connected with a motor drive system driving the vehicle, is characterized in that the power supply system includes: a fuel cell connected to the motor drive system to supply power to the motor drive system; A hydrogen supply system connected to the fuel cell to provide the fuel cell with the hydrogen energy needed to generate electricity; a fuel cell accessory coupled to the fuel cell to provide support for starting and stopping the fuel cell; An auxiliary power source is connected to the motor drive system and the fuel cell accessory respectively, and supplies power to the motor drive system and the fuel cell accessory; A power converter, connected between the fuel cell and the motor drive system, and also connected with the auxiliary power source, is used to couple the fuel cell and the auxiliary power source, and control the fuel cell and the auxiliary power source to be The motor drive system is powered, wherein the power converter includes a diode that controls the fuel cell to supply power to the motor drive system; A control element, the two ends of which are connected to the two ends of the diode of the power converter. When the power converter is not working, the control element conducts and connects the auxiliary power source and the fuel cell accessory so that the said auxiliary power source powers said fuel cell accessory; a diode, used to control the fuel cell to supply power to the fuel cell accessory, the anode of the diode is connected to the fuel cell, and the cathode of the diode is connected to the fuel cell accessory; A contactor, connected between the fuel cell and the power converter, has a first connection end and a second connection end, the first connection end is connected to the fuel cell, the second connection end is connected to the The power converter is connected to the cathode of the diode; Wherein, when the fuel cell starts, the power converter does not work, the control element is turned on, the fuel cell accessory is powered by the auxiliary power source, and the diode is reversely cut off; when the fuel cell After successful startup, the control element is turned off, the diode is forward-conducting, the fuel cell accessory is powered by the fuel cell, and the contactor is closed. 2. The power supply system of a hybrid electric vehicle according to claim 1, wherein the control element is a power tube. 3. The power supply system of a hybrid electric vehicle according to claim 1, wherein the control element is a relay. 4. The power supply system of a hybrid electric vehicle according to claim 1, wherein the power converter is a DC-DC converter. 5. The power supply system of a hybrid electric vehicle according to claim 1, wherein the fuel cell accessories include: an air compressor system and a water pump. 6. The power supply system of a hybrid electric vehicle according to claim 1, wherein the auxiliary power source is a power storage battery, a supercapacitor, or a solar cell.