Data Acquisition System Of Three-phase AC Switch Machine In Speed-raising Turnout

This thesis is based on the research of microcomputer monitoring system.Mainly research and design the switch machine power measurement.It refers to the latest international functional safety standard-IEC61508, assessing the risk of switch machine power acquisition, and completed sensor design.This thesis simply introduces the risk analysis principles and risk analysis methodologys in the IEC61508 standard, comparing and analysising of three kinds of risk assessment methods that are proposed by the standard. Qualitative risk assessment methodology is used for the power collector in risk assessment. This system needs to achieve SIL 1.Using embedded microprocessor STM32F103xx as the main control chip for hardware-circuit design.This power collector can measure the electrical parameters of the turnout system,including the voltage,current and power,it can transmit power graph by judge the switch.It send data through the RS-485 communication interface that bases on Modbus RTU protocol,with PLC, RTU and other terminals to networking.Adding zero-phase digital low-pass filter FRR to program.This digital filter that bases on IIR can achieve zero phase shift.To deal with the non-linear phase frequency in its filter.It Effectively filter out the grid voltage waveform distortion and the current waveform distortion caused by the motor load change.In accord with the requirements of IEC61508 standard,estimating the hardware failure rate of the data acquisition system.By calculating, the system's safety integrity levels of security features has achieved SIL 1.The completed power collector works well in testing both in the laboratory and the simulated field.The traditional functions are improved.The thesis concludes the main job in the last part, and introduces the deficiencies and the improvement rooms in the continued work.