The Research Of Traction Converter Of Modern Vehicle Based On DSP

With the rapid development of Chinese economy, the number of urban population have begun to increase sharply, which has brought more and more pressure to urban traffic. This leads to many cities increase urban rail transit investment, such as light rail, subway, modern vehicle. However, the subway and light rail are not suitable for establishment in the small city because of the high cost of construction. Compared to the light rail and subway, the modern vehicle has the characteristics of less investment, low traffic. And it is more suitable for the development of small cities. It compared to traditional vehicle has the advantages of fast speed, low noise, environmental protection and energy saving. And it can improve the city traffic, reducing the pollution of the city, improving the quality of life of the city.Modern trams and many rail cars are using AC transmission system. And AC drive is compared with DC transmission has the advantages of big starting traction, small size, light weight, excellent electrical braking characteristics, high sticking coefficient, electrical easy maintenance, high power factor, small equivalent interference current, etc. It has become a general trend in the development of electric traction’s technology. This thesis study modern tram traction converters under the condition of the DC bus voltage 750 V, traction motor power of 75 kW. Paper use high-speed characteristics of DSP to complete the analysis of converter control algorithm, voltage and current sampling, the function such as protection,eventually produce SVPWM wave to achieve open and shut off the control switch tube in the inverter. Paper mainly realize the converter control, analyzing the inverter control algorithm,designing main circuit and control circuit, absorbing circuit and protection circuit design,using C language to write of DSP control program.In this paper the study of AC inverter of Modern Vehicle including the following respects:1.The main part of the circuit design, the main circuit is mainly change DC to three-phase alternating current, so as to control the operation of traction motor. It is have support the calculation and selection of the capacitor; lectotype analysis and IGBT inverter circuit; IGBT absorption analysis and circuit parameters calculation.2.The analysis of the inverter control algorithm. This paper analyses the three-phase asynchronous motor control algorithm, using the speed-sensorless vector control system. And it use the SVPWM modulation technology to realize the IGBT power components to control the open and shut off.3.Control circuit design, control circuit is mainly to complete the data collection and analysis and control of the inverter. Including the type selecting of the driving and protection circuit for IGBT, in which, the integrated driver board for IGBT, 2SD315 AI, produced bySwiss CONCEPT Corporation is used; the design of the sampling and conditioning circuit for voltage,current, temperature; the design of switching power supply, and its physical circuit.4.Inverter control panel design and the software part carry on the design. The paper use HDSP-Super2812 as the control panel, on which is 32 fixed-point DSP chip, TMS320F2812,which is produced by TI Corporation. Drawing a flow chart of software, this paper analyzes the specific work process of DSP realization of SVPWM wave output. The control and sample code is written.5.The experimental circuit’s lap. Lap a narrow model of a certain power circuit, the main circuit, control circuit, absorption circuit, sampling circuit to carry on the physical structures.Burned the control program of paper is written to DSP in the control panel, and carries on the run in circuit experiment, verify the rationality of the design of the paper.