| AC drive technology since it appeared in the world has showed advantage over DC drive technology. The adherence coefficient is highly used in traction field if AC drive is employed, and the conversion between traction and brake can be directly made without the help of contact electric devices. As compared with DC drive, AC drive has higher axial power and wider constant power range, and it more suitable for high speed and heavy train transportation. It has a power factor of near 1, and decreases the harmonics interference to the lowest level. The asynchronous motor needs much less maintenance. All these advantages make AC drive in traction to be the pursuing aim of many countries.Research test must be made deeply and all things considered to the system and parts in order to develop and produce the AC drive locomotive and power head that are fit to the situation and transportation conditions of our country. The operation principle of the system and its composed parts, and the relations between the characteristics and outside environment can be known by means of research test, middle duration test and proving test. The relations and match conditions and optimize rules between the system and parts as well as among parts can also be understood with the help of research test, so the basic requirement of design and production can be confirmed. For the purpose of above, the Ministry of Railway considered the locomotive AC drive system testplatform as one of its key construction items in the ninth 5 years plan and invested 23,000,000yuans for it. The writer is the responsible person of the key construction item, and designed, installed and commissioned the test system, main circuit, and silicon controllable rectifier as well as the microcomputer monitor and control system. The test platform includes 3-axial bogie rolling test device, AC traction motor, converter, locomotive power supply and its loads, microprocessor automatic control and measurement as well as industrial TV monitor system. The microcomputer monitor and control system of locomotive AC drive system test platform (briefly called the microcomputer monitor and control system) introduced in the paper is the core device of whole test platform. It is used for whole process control of function research test, optimize design proving test, as well as relative test required in international and country standards for the AC drive system and parts of electric and diesel locomotive, motor vehicle, metro vehicle, light rail vehicle and city transportation vehicle, or in other words for the system and parts which are relative to the production and transfer of locomotive force (traction and brake) in the traction equipment in which AC drive technology is used.The constituent parts, basic principle and realization of process control of a microcomputer monitor and control system of locomotive AC drive system test platform are analyzed and introduced in this paper. The monitor and control system makes use of PLC and the proved locomotive microcomputer control devices to perform respectively the switch logical control of system and the current closed loop control of the armature circuit, and it employs an industrial control microcomputer to carry out speed or characteristics control. DOS operating system is used in the control system in order to obtain fast control refresh rate A microcomputer with windows operating system provides a friendly interface to people. The units in the system are connected together by means of series communication is in accordance with the development tide of control system. As a result the cable distribution work is reduced by proper arrangement of devices and the reliability of system is increased. |
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