CN101694417A - Dynamic performance test method of vehicle electric driving system - Google Patents

Abstract

A dynamic performance test method of a vehicle electric driving system belongs to the technical field of electric automobiles. A vehicular motor output shaft is connected and coaxial with a load motor output shaft, when in driving, power of a driving system is transmitted from a vehicular motor and a load motor to be transformed into electric energy to be stored in a super capacitor or consumed on a resistance box, when in braking, energy is transmitted from the super capacitor to be consumed by the resistance box and then fed back to a battery pack via the load motor and the vehicular motor, and then running of the load motor is controlled and actual load torque is simulated, further, a load simulation controller computes power consumed by driving resistance and power transformed to vehicle power according to current circulating speed, vehicle parameters and road conditions and controls resistance of the resistance box, namely controlling energy consumed by the resistance box to be equal to energy consumed by driving resistance. The dynamic performance test method of a vehicle electric driving system can be used for research on the driving control strategy individually and research on the braking control strategy, and simultaneously can be applied to research on the total vehicle control strategy more conveniently.

Description

Test method for dynamic working conditions of vehicle electric drive system

technical field

The invention relates to a method for simulating the running conditions of an electric vehicle on a stand, that is, a scheme for simulating the running conditions of the vehicle-mounted motor by loading the vehicle-mounted motor, and belongs to the technical field of electric vehicles.

Background technique

At present, the country puts the vigorous development of electric vehicles on the agenda. In the entire electric vehicle powertrain, the basic performance and control effect of the motor are the direct factors that affect the performance index of the vehicle. Therefore, a system that can reflect the characteristics of the motor under automotive conditions is of great significance. Taking the prototype car as the test object, although the corresponding motor results can be obtained very well, but it is not the first choice for the initial stage of R&D because of its heavy workload, long cycle, high cost, and limitations of the test site. A test bench that can more realistically simulate the driving conditions of a car can solve these problems well.

Most of the domestic test benches use dynamometers as loading equipment to test the on-board motor and its control. The embodiment of resistance energy consumption. Such a test bench is lacking in testing the characteristics of the complete vehicle.

Contents of the invention

The purpose of the present invention is to propose a bench test method for better simulating the driving state of an electric vehicle, that is, a test scheme for simulating the energy consumption of running resistance and the recovery of braking energy in the cycle of driving conditions of the electric vehicle. The motor can be in a working condition close to the real condition, and at the same time, the vehicle characteristics such as fuel economy and braking performance of the vehicle can be obtained more accurately.

According to above-mentioned object, the present invention adopts a kind of device for simulating vehicle load situation to include load motor and control system, bidirectional DC/DC, unidirectional DC/DC, supercapacitor, resistance box, speed/torque sensor and load simulation control system. The tested part of the invention includes a fuel cell simulator and its control system, a power regulator and its control system, a battery pack, a bidirectional DC/DC, an on-board motor and a controller. The load motor is rigidly connected to the vehicle motor, and the energy transfer with the supercapacitor is realized through bidirectional DC/DC, or the energy is transferred to the resistance box through unidirectional DC/DC. When the on-board motor is in the driving state, the energy flow path is equivalent power supply (battery pack and fuel cell engine), on-board motor, load motor, supercapacitor and resistance box. When the vehicle is in the braking state, the energy flow path is the super capacitor, the resistance box and the load motor, the vehicle motor, and the battery pack.

A test method for dynamic working conditions of a vehicle electric drive system, the method includes the following steps:

a. The output shaft of the on-board motor is connected to the output shaft of the load motor on the same axis. When driving, the power of the drive system is transmitted from the on-board motor to the load motor and converted into electric energy, which is stored in the super capacitor or consumed on the resistance box; when braking, the energy is transferred from the super capacitor The capacitance is transmitted, part of it is consumed by the resistance box, and part of it is fed back to the battery pack through the load motor and the on-board motor.

b. The load motor controller calculates the power demand according to the current cycle speed and the current acceleration, controls the operation of the load motor, and simulates the actual load torque.

c. The load simulation controller calculates the power consumed by the driving resistance and the power converted into vehicle kinetic energy according to the current cycle speed, vehicle parameters and road conditions, and controls the resistance value of the resistance box, that is, the energy consumed by the control resistance box is equal to the driving resistance energy expended. The energy stored in the supercapacitor is equivalent to the kinetic energy of the vehicle (including the kinetic energy of the rotating parts).

The method for simulating driving conditions of the present invention can be used alone for the research of driving control strategy, also can be used for the research of braking control strategy alone, and can also be used for the research of vehicle control strategy, including driving state and brake control strategy. dynamic state. It is more convenient to study the vehicle economy, vehicle energy management and control strategy.

Description of drawings

Fig. 1 is a schematic structural view of a fuel cell electric vehicle test bench applied in the present invention.

In the figure: 1 represents the fuel cell simulator, 2 represents the power regulator, 3 represents the battery pack, 4 and 8 represent the bidirectional DC/DC, 5 represents the on-board motor, 6 represents the load motor, 7 represents the unidirectional DC/DC, and 9 represents the Supercapacitor, 10 means resistance box, 11 means speed/torque sensor, 12 means fuel cell analog controller, 13 means vehicle motor controller, 14 means load motor controller, 15 means power regulation controller, 16 means load analog control device.

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments.

Referring to Fig. 1, when the vehicle is in the driving state, the fuel cell simulator 1 and the battery pack 3 jointly provide electric energy to the on-board motor 5 under the coordinated control of the power regulation controller 15, and the on-board motor 5 is under the control of the on-board motor controller 13 The electrical energy is converted into mechanical energy and transmitted to the load motor 6. The load motor controller 14 obtains the power demand by calculating the current vehicle speed and acceleration, etc., thereby controlling the load motor 6 to convert the mechanical energy into electrical energy. At the same time, the load simulation controller 16 calculates the driving resistance (including (rolling resistance, air resistance, etc.) account for the proportion of the total power, and control the power consumed by the resistance box 10. At this time, the electric energy obtained and stored by the supercapacitor 9 can be expressed as the kinetic energy of the vehicle (including the kinetic energy of the rotating parts) .

When the vehicle is under braking, the bench will simulate the process of converting the kinetic energy of the vehicle into electrical energy storage. At this time, part of the electric energy equivalent to the kinetic energy of the vehicle in the supercapacitor 9 is sent to the resistance box 10 according to the consumption of running resistance under the control of the load analog controller 16, and the other part is converted into heat energy and dissipated according to the load motor controller 14. The control of the load motor 6 is converted into mechanical energy and sent to the vehicle-mounted motor 5. Under the control of the vehicle-mounted motor controller 13, the vehicle-mounted motor 5 acts as a generator to convert mechanical energy into electrical energy and feed it back to the battery pack 3 to complete the simulation process of braking feedback.

The method of simulating the driving conditions of the vehicle with supercapacitors and resistors described in the above embodiments can be used for the research of the energy management strategy of the driving part and the research of the energy management strategy of the braking part at the same time, ensuring the integrity and comprehensiveness of the test sex.

The present invention is not limited to the above embodiments, that is to say, it is not limited to the fuel cell electric vehicle test bench, and it is also applicable to the driving condition simulation of the pure electric vehicle test bench and the hybrid electric vehicle test bench.

Claims (1)

1. A method for testing dynamic working conditions of a vehicle electric drive system, characterized in that the method comprises steps: a. The output shaft of the on-board motor is connected to the output shaft of the load motor on the same axis. When driving, the power of the drive system is transmitted from the on-board motor to the load motor and converted into electric energy, which is stored in the super capacitor or consumed on the resistance box; when braking, the energy is transferred from the super capacitor The capacitance is transmitted, part of it is consumed by the resistance box, and part of it is fed back to the battery pack through the load motor and the vehicle motor; b. The load motor controller calculates the power demand according to the current cycle speed and the current acceleration, controls the operation of the load motor, and simulates the actual load torque; c. The load simulation controller calculates the power consumed by the driving resistance and the power converted into vehicle kinetic energy according to the current cycle speed, vehicle parameters and road conditions, and controls the resistance value of the resistance box, that is, the energy consumed by the control resistance box is equal to the driving resistance The energy consumed; the energy stored in the supercapacitor is equivalent to the kinetic energy of the vehicle.

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