Power system of hybrid vehicle

Abstract

The utility model discloses a power system of a hybrid power vehicle, which relates to a hybrid power system and comprises an engine, a generator, a motor, a converter, a power battery and a vehicle driving system. An energy buffer module is arranged between the converter and the power battery, the input common end of the energy buffer module is provided with a charging branch and a discharging branch, the charging branch is electrically connected with the other output end of the converter through a first control switch, and the discharging branch is electrically connected with the input end of the power battery through a fifth control switch; and the first control switch, the fifth control switch, the charging branch and the discharging branch form a direct charging circuit of the converter-power battery. According to the utility model, the charging frequency of the power battery is greatly reduced, and the service life of the power battery is prolonged.

Description

Technical Field

[0001] The utility model relates to a hybrid power system, and more specifically, to a power system of a hybrid power vehicle. Background Art

[0002] Hybrid vehicles combine internal combustion engines and electric motors to provide power. The distribution of torque in each part depends on the coordinated interaction between the internal combustion engine, electric motor, transmission, battery and control system. Each component plays a specific role in the process of managing and distributing torque according to driving conditions and operating requirements. Effectively managing the torque distribution between these power sources and dynamically adjusting the torque to each wheel can enhance vehicle stability, cornering performance and overall handling, and is also crucial to optimizing vehicle performance, fuel efficiency and emissions.

[0003] In order to achieve safe, efficient and high-performance operation of hybrid vehicles, some related public technologies use a series structure of electric motors and internal combustion engines. The internal combustion engine is not directly connected to the drive wheels. The internal combustion engine drives the generator to generate electricity, and the torque distribution between the internal combustion engine and the motor is adjusted according to the most efficient way. Other public technologies use a parallel structure of electric motors and internal combustion engines. Both the internal combustion engine and the electric motor are connected to the drive system. The torque of the internal combustion engine and the electric motor is dynamically distributed according to the vehicle's operating status, which can reduce the number of energy conversions.

[0004] Regardless of the technology, hybrid vehicles enter the energy recovery state to recover energy under braking, driving with the throttle opening at zero (such as going downhill), and other working conditions to increase the battery life. In the process of energy recovery, the kinetic energy of the vehicle is often converted into electrical energy through a generator, and then stored in the power battery through a converter. However, the power battery has a certain charge and discharge life, and kinetic energy recovery has the characteristics of strong randomness and high frequency, which leads to frequent charging and discharging of the power battery during operation, which will affect the life of the power battery and reduce its life. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a power system of a hybrid vehicle in view of the deficiencies of the prior art, which greatly reduces the number of times of charging the power battery.

[0006] A power system of a hybrid vehicle described in the utility model includes an engine, a generator, an electric motor, a converter, a power battery and a vehicle drive system; the engine is transmission-connected to the generator, the generator is also transmission-connected to the vehicle drive system, the output end of the generator is electrically connected to an input end of the converter, the output end of the power battery is electrically connected to the other input end of the converter, an output end of the converter is electrically connected to the input end of the electric motor, the power output end of the electric motor is transmission-connected to the vehicle drive system, an energy buffer module is provided between the converter and the power battery, the input common end of the energy buffer module is provided with a charging branch and a discharging branch, the charging branch is electrically connected to the other output end of the converter through a first control switch, and the discharging branch is electrically connected to the input end of the power battery through a fifth control switch; the first control switch, the fifth control switch, the charging branch and the discharging branch constitute a converter-power battery direct charging circuit.

[0007] Preferably, the energy buffer module comprises a plurality of accumulators, a common end of the plurality of accumulators is connected in parallel, the other common ends of the plurality of accumulators are each connected to a control switch in a one-to-one correspondence, and the other ends of the plurality of control switches are simultaneously connected to the first control switch.

[0008] Preferably, the energy storage device is a super capacitor.

[0009] Preferably, all control switches are relays.

[0010] Preferably, a sixth control switch is installed on the circuit between the generator and the converter.

[0011] Beneficial Effects

[0012] The advantages of the utility model are that an energy buffer module is arranged between the converter and the power battery, and a direct charging circuit for directly charging the power battery and a charging branch for charging and storing energy in the energy buffer module are formed through two branches and two control switches, so that the energy in the energy recovery mode is pre-stored and then released to charge the power battery without affecting the charging of the power battery through the engine, thereby greatly reducing the number of times the power battery is charged and playing a role in improving the service life of the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the power system structure of the utility model.

[0014] Among them: 1-generator, 2-engine, 3-motor, 4-converter, 5-power battery, 6-energy buffer module, 7-gear set, 8-first gear train, 9-second gear train, 10-drive shaft, 11-vehicle drive system, 12-charging branch, 13-discharging branch, 61-first accumulator, 62-second accumulator, 63-third accumulator, 101-first control switch, 102-second control switch, 103-third control switch, 104-fourth control switch, 105-fifth control switch, 106-sixth control switch. DETAILED DESCRIPTION

[0015] The utility model is further described below in conjunction with the embodiments, but does not constitute any limitation to the utility model. Any limited modifications made by anyone within the scope of the claims of the utility model are still within the scope of the claims of the utility model.

[0016] See also Figure 1 The utility model discloses a power system of a hybrid vehicle, comprising an engine 2, a generator 1, an electric motor 3, a converter 4, a power battery 5 and a vehicle drive system 11. The engine 2 is connected to the generator 1 through a gear set 7, the driving end of the generator 1 is connected to a first gear train 8, the first gear train 8 is connected to a second gear train 9 through a first clutch, the second gear train 9 is connected to the vehicle drive system 11, and the second gear train 9 is also connected to the power output end of the electric motor 3 through a transmission shaft 10 and a second clutch. The output end of the generator 1 is electrically connected to an input end of the converter 4 through a sixth control switch 106, the output end of the power battery 5 is electrically connected to another input end of the converter 4, and an output end of the converter 4 is electrically connected to the input end of the electric motor 3.

[0017] When the power battery 5 transmits electric energy to the motor 3 through the converter 4, the motor 3 transmits power to the vehicle drive system 11 through the transmission shaft 10, the second clutch and the second gear train 9, so that the vehicle runs. At this time, the first clutch separates the two gear trains. When the vehicle enters the energy recovery mode, the energy of the vehicle drive system 11 acts on the generator 1 through the second gear train 9, the first clutch and the first gear train 8 to make it work, so that the generator 1 runs and generates electricity under the action of the vehicle drive system 11. At this time, the second clutch separates the transmission shaft 10 and the second gear train 9.

[0018] An energy buffer module 6 is provided between the converter 4 and the power battery 5. A charging branch 12 and a discharging branch 13 are provided at the input common end of the energy buffer module 6. The charging branch 12 is electrically connected to the other output end of the converter 4 through the first control switch 101, and the discharging branch 13 is electrically connected to the input end of the power battery 5 through the fifth control switch 105. The first control switch 101, the fifth control switch 105, the charging branch 12 and the discharging branch 13 constitute a converter-power battery direct charging circuit. That is, there are two ways to charge the power battery 5 in this embodiment.

[0019] The first charging method is: when the SOC of the power battery 5 is lower than the set threshold, which is generally 20%-30% according to the prior art, the engine 2 will start, drive the generator 1 to generate electricity, and the electric energy generated by the generator 1 will be transmitted to the converter 4. When the engine 2 is started, the first control switch 101 and the fifth control switch 105 are closed and turned on at the same time, and the control switches in the energy buffer module 6, that is, the second to fourth control switches are all in the disconnected state. At this time, the direct charging circuit between the converter 4 and the power battery 5 is turned on, and the output electric energy of the converter 4 will be transmitted to the power battery 5 through the direct charging circuit to realize the charging of the power battery 5.

[0020] The second charging method is: when the vehicle enters the energy recovery mode, the first control switch 101 is in a closed and conductive state, and the fifth control switch 105 is in an open state. At this time, the electric energy generated by the generator 1 will be transmitted to the energy buffer module 6 through the converter 4 and the first control switch 101, and stored by the energy buffer module 6. When the electric energy in the energy buffer module 6 is fully stored, the first control switch 101 is disconnected, and the fifth control switch 105 is closed and turned on, so that the electric energy in the energy buffer module 6 is released to the power battery 5, thereby realizing the charging of the power battery 5. Due to the pre-energy storage function of the energy buffer module 6, it can store the electric energy generated by multiple energy recovery modes, and then release it to the power battery 5 at one time to charge it, thereby greatly reducing the number of times the power battery 5 is charged, and playing a role in improving the service life of the power battery 5.

[0021] In this embodiment, the energy buffer module 6 includes three accumulators. The accumulators are supercapacitors. Compared with batteries, supercapacitors are used as accumulators, which have higher power density and longer cycle life, and can well meet the energy recovery requirements in the energy recovery mode. A common end of the three accumulators is connected in parallel, and the other ends of the three accumulators are connected to a control switch one by one, namely, the second control switch 102, the third control switch 103 and the fourth control switch 104, and the other ends of the three control switches are simultaneously connected to the first control switch 101.

[0022] During the energy recovery process, the electric energy output by the converter 4 can be stored in the energy accumulator by controlling the second control switch 102, the third control switch 103 and the fourth control switch 104. Its working mode can be that the three control switches are closed at the same time, so that the electric energy output by the converter 4 is stored in the three energy accumulators at the same time; or one of the control switches, such as only the second control switch 102, is closed to store the recovered energy in the first energy accumulator 61, and after the energy is fully stored, the third control switch 103 is closed to store the energy through the second energy accumulator 62. When the three energy accumulators are fully stored, the three control switches are closed at the same time to release the electric energy to charge the power battery 5.

[0023] In this embodiment, all control switches are relays.

[0024] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A power system for a hybrid vehicle, comprising an engine (2), a generator (1), an electric motor (3), a converter (4), a power battery (5) and a vehicle drive system (11); the engine (2) is transmission-connected to the generator (1), the generator (1) is also transmission-connected to the vehicle drive system (11), the output end of the generator (1) is electrically connected to an input end of the converter (4), the output end of the power battery (5) is electrically connected to another input end of the converter (4), an output end of the converter (4) is electrically connected to an input end of the electric motor (3), and the power output end of the electric motor (3) is transmission-connected to the vehicle drive system (11), characterized in that: An energy buffer module (6) is provided between the converter (4) and the power battery (5); a charging branch (12) and a discharging branch (13) are provided at the input common end of the energy buffer module (6); the charging branch (12) is electrically connected to the other output end of the converter (4) through a first control switch (101); and the discharging branch (13) is electrically connected to the input end of the power battery (5) through a fifth control switch (105); the first control switch (101), the fifth control switch (105), the charging branch (12) and the discharging branch (13) constitute a converter-power battery direct charging circuit.

2. A power system for a hybrid vehicle according to claim 1, characterized in that: The energy buffer module (6) comprises a plurality of energy accumulators, a common end of the plurality of energy accumulators is connected in parallel, the other common ends of the plurality of energy accumulators are each connected to a control switch in a one-to-one correspondence, and the other ends of the plurality of control switches are simultaneously connected to a first control switch (101).

3. A power system for a hybrid vehicle according to claim 2, characterized in that: The energy accumulator is a super capacitor.

4. A power system for a hybrid vehicle according to claim 2, characterized in that: All control switches are relays.

5. The power system of a hybrid vehicle according to claim 1, characterized in that: A sixth control switch (106) is installed on the circuit between the generator (1) and the converter (4).

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