Electric vehicle power system and driving control method thereof

Abstract

The invention discloses an electric vehicle power system and a driving control method thereof, and the electric vehicle power system comprises a motor which is used for driving a hub to rotate; the storage battery pack is used for storing and outputting electric power and providing power for the electric vehicle; and the frequency converter is used for adjusting the voltage and the frequency of the output power supply of the storage battery pack and providing the power supply voltage required by the motor. The beneficial effects are that a signal can be sent out through rotation of the electric switch to enable the controller to control the motor, the frequency converter can provide power for the motor and the controller after filtering, frequency conversion and voltage transformation are carried out on power provided by the storage battery pack, and required power supply voltage is provided according to actual needs; therefore, the purpose of saving energy is achieved.

Description

Technical Field

[0001] The present invention relates to the field of controlling electric vehicles or driving electric motors, and in particular to an electric vehicle power system and a drive control method thereof. Background Art

[0002] Electric vehicles, that is, electric-drive vehicles, convert electrical energy into mechanical energy through controllers, motors and other components to control the current to change the output power of the motor, thereby driving the wheels to rotate through the motor and adjusting the vehicle speed to facilitate people's daily travel. Electric vehicles do not account for a very high share of the national economy, but they are in line with the energy-saving and environmental protection trends set by the country, greatly facilitating short-distance transportation, and most importantly, playing an important role in the national economy through saving and protecting energy and the environment.

[0003] When an electric vehicle is used for travel, the usual operation on downhill sections is to release the accelerator to allow the electric vehicle to move forward under the action of inertia. On downhill sections, due to the effect of inertia, the electric vehicle will continue to rush downward, and the speed of the electric vehicle will gradually increase. At this time, the rider needs to constantly adjust and reduce the speed by controlling the brakes. The long-term friction of the brake disc will cause the temperature to rise and lead to failure of the brake components, thereby increasing the probability of traffic accidents.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0005] The object of the present invention is to provide an electric vehicle power system to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] According to one aspect of the invention, a power system for an electric vehicle is provided.

[0008] The electric vehicle power system comprises:

[0009] An electric motor, wherein the electric motor is used to drive the wheel hub to rotate;

[0010] A braking mechanism, the braking mechanism is used to slow down the wheel hub;

[0011] A battery pack, the battery pack is used to store and output electricity to provide power for the electric vehicle;

[0012] A frequency converter, the frequency converter is used to adjust the voltage and frequency of the output power of the battery pack to provide the power supply voltage required by the motor;

[0013] A reducer, the reducer is used to match the rotation speed and transmit torque between the motor and the wheel hub;

[0014] A P gear switch, the P gear switch is used to control the braking mechanism to slow down the wheel hub;

[0015] A switch, the switch is used to control the output power of the motor;

[0016] A controller is used to receive signals from the ignition switch and the P gear switch.

[0017] Further, the braking mechanism includes a rotor and a stator;

[0018] Furthermore, the stator is fixed on the vehicle frame, and an electromagnetic coil for braking the rotor is installed inside the stator;

[0019] Furthermore, the rotor is arranged in the stator, and is mounted on the axle between the wheel hubs to maintain a common movement speed with the axle.

[0020] Furthermore, a power generation circuit is installed on one side of the rotor, and the power generation circuit charges the battery pack through rectification of the inverter.

[0021] Furthermore, a rotation speed sensor is installed in the stator, and the rotation speed sensor is used to monitor the rotation speed of the rotor.

[0022] According to another aspect of the present invention, a driving control method for an electric vehicle is provided, which is used for the above-mentioned electric vehicle power system.

[0023] The electric vehicle driving control method comprises the following steps:

[0024] S101, the battery pack provides power to the inverter;

[0025] S102, the frequency converter filters, converts the frequency and voltage of the power and then provides power to the motor and the controller;

[0026] S103, turning the switch so that the switch sends a signal to the controller;

[0027] S104, the controller receives the signal and then controls the motor to run;

[0028] S105, the motor runs, driving the wheel hub to rotate and the electric vehicle moves forward;

[0029] S106, when going downhill, press the P gear switch;

[0030] S107, after receiving the P gear switch signal, the controller controls the frequency converter to provide power to the electromagnetic coil;

[0031] S108, the electromagnetic coil generates magnetic force to brake the rotor and reduce the rotor speed;

[0032] S109, the rotor is braked by the electromagnetic coil, driving the wheel hub to slow down.

[0033] Further, based on S108, when the rotor is rotating, the speed sensor detects the rotor;

[0034] Further, based on S109, when the rotor speed is still too high, the speed sensor transmits information to the controller, so that the controller controls the inverter to increase the output power of the electromagnetic coil, thereby increasing the braking effect on the rotor, reducing the rotor speed, and reducing the speed of the electric vehicle on the downhill slope;

[0035] Further, based on S109, when the speed of the rotor is low, the speed sensor transmits information to the controller, so that the controller controls the inverter to reduce the output power of the electromagnetic coil, thereby reducing the braking effect on the rotor and preventing the rotor from stopping due to braking by the electromagnetic coil.

[0036] Further, based on S108, when the electromagnetic coil generates magnetic force to brake the rotor, the rotor cuts the magnetic flux lines due to rotation to generate induced current, and the battery pack is charged through the power generation circuit, thereby reducing power loss.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) By turning the set electric switch, a signal can be sent to enable the controller to control the motor, and the set frequency converter can filter, convert the frequency and voltage of the power provided by the battery pack and then provide power to the motor and controller, providing the required power voltage according to actual needs, thereby achieving the purpose of energy saving, and the set P gear switch can send a signal to the controller, so that the controller controls the frequency converter to power the braking mechanism, thereby generating magnetic force through the electromagnetic coil in the braking mechanism to brake the rotor, so that the rotor drives the axle to slow down, thereby slowing down the rotation speed of the wheel hub, slowing down the speed of the electric vehicle during the downhill process, and increasing the safety of the electric vehicle during the downhill process.

[0039] (2) The electromagnetic coil arranged inside the stator can generate magnetic force through the power supply of the frequency converter, thereby applying a braking torque to the rotor, reducing the rotation speed of the rotor, thereby reducing the speed of the electric vehicle during the downhill process, avoiding the vehicle from losing control due to excessive speed, and the speed sensor arranged can detect the rotation speed of the rotor. When the rotation speed of the rotor is too high, the speed sensor sends a signal to the controller, causing the controller to increase the power output of the frequency converter, thereby increasing the braking torque applied by the electromagnetic coil to the rotor, and further reducing the speed of the rotor. When the rotor speed is low, the rotation sensor will send a signal to the controller to reduce the output power of the frequency converter, thereby reducing the braking torque applied by the electromagnetic coil to the rotor, thereby avoiding the vehicle from stopping moving during the downhill process. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 is a system operation flow chart of an electric vehicle power system according to an embodiment of the present invention;

[0042] Figure 2 is a flow chart of a driving control method of an electric vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0044] According to an embodiment of the present invention, a power system for an electric vehicle is provided.

[0045] Embodiment 1:

[0046] like Figure 1 As shown, the electric vehicle power system according to an embodiment of the present invention includes:

[0047] An electric motor, wherein the electric motor is used to drive the wheel hub to rotate;

[0048] A braking mechanism, the braking mechanism is used to slow down the wheel hub;

[0049] A battery pack, the battery pack is used to store and output electricity to provide power for the electric vehicle;

[0050] A frequency converter, the frequency converter is used to adjust the voltage and frequency of the output power of the battery pack to provide the power supply voltage required by the motor;

[0051] A reducer, the reducer is used to match the rotation speed and transmit torque between the motor and the wheel hub;

[0052] A P gear switch, the P gear switch is used to control the braking mechanism to slow down the wheel hub;

[0053] A switch, the switch is used to control the output power of the motor;

[0054] A controller is used to receive signals from the ignition switch and the P gear switch.

[0055] Through the above scheme of the present invention, by rotating the set electric switch, a signal can be sent to enable the controller to control the motor, and the set frequency converter can filter, convert the frequency and voltage of the power provided by the battery pack and then provide power to the motor and the controller, and provide the required power supply voltage according to actual needs, thereby achieving the purpose of energy saving, and the set P gear switch can send a signal to the controller, so that the controller controls the frequency converter to power the braking mechanism, so that the electromagnetic coil in the braking mechanism generates magnetic force to brake the rotor, so that the rotor drives the axle to slow down, thereby slowing down the rotation speed of the wheel hub, slowing down the speed of the electric vehicle during downhill, and increasing the safety of the electric vehicle during downhill.

[0056] Embodiment 2:

[0057] According to an electric vehicle power system of an embodiment of the present invention, the braking mechanism includes a rotor and a stator; the stator is fixed on the frame, and an electromagnetic coil for braking the rotor is installed inside the stator; the rotor is arranged in the stator, which is installed on the axle between the wheel hubs and maintains a common movement speed with the axle, a power generation circuit is installed on one side of the rotor, and the power generation circuit charges the battery pack through the rectification of the inverter, and a speed sensor is installed in the stator, and the speed sensor is used to monitor the speed of the rotor.

[0058] Through the above scheme of the present invention, the electromagnetic coil is arranged inside the stator, and the power supply of the frequency converter can be used to make the electromagnetic coil generate magnetic force, thereby applying a braking torque to the rotor, reducing the rotation speed of the rotor, thereby reducing the speed of the electric vehicle during the downhill process, avoiding the vehicle from losing control due to excessive speed, and the speed sensor arranged can detect the rotation speed of the rotor. When the rotation speed of the rotor is too high, the speed sensor sends a signal to the controller, causing the controller to increase the power output of the frequency converter, thereby increasing the braking torque applied by the electromagnetic coil to the rotor, and further reducing the speed of the rotor. When the rotor speed is low, the rotation sensor will send a signal to the controller to cause the controller to reduce the output power of the frequency converter, reducing the braking torque applied by the electromagnetic coil to the rotor, thereby avoiding the vehicle from stopping moving during the downhill process.

[0059] Embodiment three:

[0060] See also Figure 2 According to an embodiment of the present invention, a driving control method for an electric vehicle comprises the following steps:

[0061] S101, the battery pack provides power to the inverter;

[0062] S102, the frequency converter filters, converts the frequency and voltage of the power and then provides power to the motor and the controller;

[0063] S103, turning the switch so that the switch sends a signal to the controller;

[0064] S104, the controller receives the signal and then controls the motor to run;

[0065] S105, the motor runs, driving the wheel hub to rotate and the electric vehicle moves forward;

[0066] S106, when going downhill, press the P gear switch;

[0067] S107, after receiving the P gear switch signal, the controller controls the frequency converter to provide power to the electromagnetic coil;

[0068] S108, the electromagnetic coil generates magnetic force to brake the rotor and reduce the rotor speed;

[0069] S109, the rotor is braked by the electromagnetic coil, driving the wheel hub to slow down.

[0070] In one embodiment, based on S108, when the rotor is rotating, the speed sensor detects the rotor;

[0071] Based on S109, when the rotor speed is still too high, the speed sensor transmits information to the controller, so that the controller controls the inverter to increase the output power of the electromagnetic coil, increase the braking effect on the rotor, reduce the rotor speed, and reduce the speed of the electric vehicle on the downhill slope;

[0072] Based on S109, when the rotor speed is low, the speed sensor transmits information to the controller, so that the controller controls the inverter to reduce the output power of the electromagnetic coil, thereby reducing the braking effect on the rotor and preventing the rotor from stopping due to the braking of the electromagnetic coil.

[0073] Based on S108, when the electromagnetic coil generates magnetic force to brake the rotor, the rotor cuts the magnetic flux lines due to rotation to generate induced current, which charges the battery pack through the power generation circuit to reduce power loss.

[0074] In order to facilitate understanding of the above technical solutions of the present invention, the working principle or operation mode of the present invention in the actual process is described in detail below.

[0075] In actual application, a signal is sent by turning the electric switch, and the controller starts the motor after receiving the signal from the electric switch, thereby driving the electric vehicle to move. According to the different rotation angles of the electric switch, the output degree of the signal is different, and the controller adjusts the output power of the motor differently, so that the speed of the electric vehicle can be adjusted. When on a downhill section, turn on the P gear switch. At this time, the P gear switch sends a signal to enable the controller to control the inverter to power the braking mechanism. When the braking mechanism obtains power, the electromagnetic coil in the stator generates a magnetic field, thereby generating a resistance torque on the rotor that must be applied to stop or slow down the mechanical moving parts, slowing down the rotor, thereby reducing the rotor speed, and the speed sensor set can detect the rotor speed. Speed, and then transmit the data to the controller. When the rotor speed is too high, the controller increases the output power of the inverter to the electromagnetic coil, thereby increasing the braking torque generated by the electromagnetic coil on the rotor, increasing the resistance when the rotor rotates, thereby reducing the rotor speed, reducing the speed of the axle and wheel hub, and slowing down the electric vehicle when going downhill. When the rotor speed is low, the controller will reduce the output power of the inverter to weaken the braking torque of the electromagnetic coil on the rotor, thereby preventing the rotor from stopping and causing the vehicle to stop. When the electromagnetic coil applies braking torque to the rotor, the rotation of the rotor will cut the magnetic lines of force to generate current, which will charge the battery pack, thereby reducing the power loss of the electric vehicle when going downhill at a uniform speed.

[0076] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electric vehicle power system, characterized in that: include: An electric motor, wherein the electric motor is used to drive the wheel hub to rotate; A braking mechanism, the braking mechanism is used to slow down the wheel hub; A battery pack, the battery pack is used to store and output electricity to provide power for the electric vehicle; A frequency converter, the frequency converter is used to adjust the voltage and frequency of the output power of the battery pack to provide the power supply voltage required by the motor; A reducer, the reducer is used to match the rotation speed and transmit torque between the motor and the wheel hub; A P gear switch, the P gear switch is used to control the braking mechanism to slow down the wheel hub; A switch, the switch is used to control the output power of the motor; A controller is used to receive signals from the ignition switch and the P gear switch.

2. The electric vehicle power system according to claim 1, characterized in that: The braking mechanism includes a rotor and a stator; The stator is fixed on the vehicle frame, and an electromagnetic coil for braking the rotor is installed inside the stator; The rotor is arranged in the stator and is mounted on the axle between the wheel hubs to keep a common movement speed with the axle.

3. The electric vehicle power system according to claim 2, characterized in that: A power generation circuit is installed on one side of the rotor, and the power generation circuit charges the battery pack through rectification of the inverter.

4. The electric vehicle power system according to claim 2, characterized in that: A rotation speed sensor is installed in the stator, and the rotation speed sensor is used to monitor the rotation speed of the rotor.

5. A driving control method for an electric vehicle power system, characterized in that: An electric vehicle power system according to any one of claims 1 to 4, comprising the following steps: S101, the battery pack provides power to the inverter; S102, the frequency converter filters, converts the frequency and voltage of the power and then provides power to the motor and the controller; S103, turning the switch so that the switch sends a signal to the controller; S104, the controller receives the signal and then controls the motor to run; S105, the motor runs, driving the wheel hub to rotate and the electric vehicle moves forward; S106, when going downhill, press the P gear switch; S107, after receiving the P gear switch signal, the controller controls the frequency converter to provide power to the electromagnetic coil; S108, the electromagnetic coil generates magnetic force to brake the rotor and reduce the rotor speed; S109, the rotor is braked by the electromagnetic coil, driving the wheel hub to slow down.

6. The driving control method of an electric vehicle power system according to claim 5, characterized in that: Based on S108, when the rotor is rotating, the speed sensor will detect the rotor; Based on S109, when the rotor speed is still too high, the speed sensor transmits information to the controller, so that the controller controls the inverter to increase the output power of the electromagnetic coil, increase the braking effect on the rotor, reduce the rotor speed, and reduce the speed of the electric vehicle on the downhill slope; Based on S109, when the rotor speed is low, the speed sensor transmits information to the controller, so that the controller controls the inverter to reduce the output power of the electromagnetic coil, reduce the braking effect on the rotor, and prevent the rotor from being braked by the electromagnetic coil and stopping.

7. The driving control method of an electric vehicle power system according to claim 5, characterized in that: Based on S108, when the electromagnetic coil generates magnetic force to brake the rotor, the rotor cuts the magnetic flux lines due to rotation to generate induced current, which charges the battery pack through the power generation circuit to reduce power loss.

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