1、学 号 年 级 专 业 系(院) 指导教师评语: 签名: 年 月 日外文文献及译文Converter reference design(1) Converter Selection: Selection to determine the frequency converter when the following points: 1) The purpose of a variable frequency; constant pressure to control or constant current control. 2) the load converter types such as
2、leaves or pump volume pumps, with special attention to load the performance curve, the performance curve of the decision of the ways and means. 3) the frequency converter and load matching Voltage match: a rated voltage converter with a rated voltage line with the load. Current matches: ordinary pum
3、p, the rated current inverter and motor rated current match. For special load such as deep-water pumps, and so on need to refer to the electrical performance parameters to determine the most current inverter current and Guozainengli. Torque match: in this case constant torque load or slow down when
4、the device may have occurred. 4) the use of high-speed motor drive inverter, because of the high-speed motor, anti-small, high harmonics lead to increased output current value increases. So for high-speed motor inverter Selection, its capacity to be slightly larger than the ordinary motor selection.
5、 5) If the frequency converter to a long cable run, this time to take measures to curb the long cable to the impact of capacitive coupling, inadequate efforts to avoid converter, so in this case, the drive to enlarge the capacity of a file or the converter Output installed output reactor. 6) For the
6、 application of some special occasions, such as high temperatures, high altitude, at this time would cause the down converter capacity, the drive to enlarge the capacity of a block. (2) inverter control schematic design: 1) First confirmation of the installation environment Converter Operating tempe
7、rature: high-power converter is the internal electronic components, vulnerable to the effects of temperature, product general requirements for 0 55 , but in order to ensure the safe, reliable, the use of room to be taken into account, the best control in 40 below. In the control box, the converter b
8、ox should generally be installed in the upper and strictly comply with the Manual of installation requirements, absolutely not be allowed to heating elements or components easily fever close to the converter installed at the bottom. Ambient temperature: the temperature is too high and large temperat
9、ure changes, within easy converter there is dew, the insulation properties will be greatly reduced, or even short-circuit caused the accident. When necessary, to be added to the desiccant in the box and heater. In water treatment, generally heavier than water vapor, if the temperature changes, then
10、this problem would be more prominent. Corrosive gases: the use of the environment if the corrosive gas concentrations, will not only lead corrosion of components, printed circuit boards, but it will also accelerate the aging of plastic devices, reducing insulation properties. Vibration and shock: th
11、e control cabinet with converter by vibration and mechanical shocks will cause electrical connection is bad. Huaian thermoelectric there such a problem. Apart from raising the control cabinet at this time of the mechanical strength, vibration and shock away from the source, we must also use seismic
12、rubber pad fixed within and outside the control cabinet, such as electromagnetic switches have a vibration components. Equipment operation after a period of time and should conduct inspections and maintenance. Electromagnetic interference: Inverter at work due to rectification and frequency, produce
13、 around a lot of electromagnetic interference, these high-frequency electromagnetic waves in the vicinity of the instrument, apparatus, a certain interference. Therefore, the cabinet instrumentation and electronic systems, it should be optional metal, shielding the inverter instrument interference.
14、All the components should be reliable grounding, in addition, the electrical components, equipment and instrumentation should use the connectivity between the shielding control cables, and the shield should be grounded. If handled properly electromagnetic interference, often cause the entire system
15、does not work, leading to the control unit failure or damage. 2) Drives and determine the distance between the electrical cables and wiring methods Drives and motor the short distance should be as much as possible. This reduces the capacitance of the cable, reducing the emission source of interferen
16、ce. Control cables optional shielded cable, power cable or optional shielding from the cable converter to use all the threads of the electrical shield. Electric cables should be independent of the other cable alignment, the minimum distance of 500 mm. At the same time should avoid the electrical cables and other long-running cable lines, in or
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