The Research Of Energy Feedback Automotive AC Chassis Dynamometer Based On LabVIEW

Among the automotive interior bench testing equipment, the chassis dynamometer hasbeen occupying an important position. It can detect the performance of automotive withoutthe disintegration of automotive, such as power test, emissions testing and fault diagnosis.In the21st century, with the rapid development of automobile industry, the performanceand quality of vehicle have become more sophisticated, so the technology of auto detectionand diagnosis have to accelerate the pace of development, especially the test accuracy andreliability of the chassis dynamometer also put forward higher requirements.However, most existing domestic chassis dynamometer are mechanical structures andeddy current type, That is to say, using inertia flywheel to simulate the accelerationresistance of the car. But, the simulation of inertial flywheel can only have limited Level,according to different models to choose different inertial flywheel to simulate Inertial force.This method can accurately simulate the resistance in the case of with fixed or less models,due to existing more vehicle models, mechanical flywheel simulation methods have beenunable to meet the needs of the modern automobile detection. Eddy current type convertelectrical energy into mechanical energy to drive wheels to test engine power, now bewidely used, its main drawback is that it need to consume more energy, and part of energyconverted into thermal energy consumption away.In this paper, after reading a lot of relevant information, learning from the advancedresearch, proposing a kind of the energy feedback automobile AC chassis dynamometer,mainly from the following aspects:Firstly, introducing the development of the technology of major automobile detectionand diagnosis and chassis dynamometer at home and abroad, and doing a bit outlook forauto detection and diagnosis techniques of our country. Then, analyzing the principles ofchassis dynamometer and introducing the main components of the chassis dynamometer,analyzing the resistance on the road and on the chassis dynamometer, giving a simulationmodel of resistance on the chassis dynamometer. Finally, giving a implementation scheme of energy feedback automotive AC chassis dynamometer.For the proposed scheme, study of the "AC-DC" grid-side energy feedback system andthe "DC-AC" motor side of the motor control system be made. The "AC-DC" grid-sideenergy feedback system uses a three-phase PWM converter technology, and giving a deepanalysis and simulation studies. In order to achieve unity power factor of the grid-sidecurrent control, using a double-loop control to achieve and maintain a stable DC voltage,control grid-side high current harmonics, reduce the injury of harmonics on the grid. The"DC-AC" motor side control system using direct torque control technology, and givinganalysis and simulation.After designing and researching the control structure of the Scheme, the mainhardware components of the system were selected, including data acquisition card andspeed sensor and torque sensor, etc. While using LabVIEW to design the software part ofthe test system, design the test software of main test items, including the slidingperformance testing software, acceleration testing software, the output power of the drivewheel testing software and data acquisition software, security software, ect.After completing the design of control system, hardware and software, in order toverify the accuracy of the system, real vehicle tests and simulation experiments werecarried out. Before real vehicle test, inspected and calibrated the test equipment to ensurethe accuracy of the tests. The real vehicle test experimental data and simulation results arecompared, test the matching degree of data under two experimental conditions. The resultsindicates that the accuracy of the system be required.