1、 毕业设计（ 外文翻译 ） 英文 题目 Based on PLC dual power switch design 中文题目 基于 PLC 双电源开关设计 系 （院） 自动化系 专 业 电气自动化技术 学生姓名 曹成帅 李广斌 孙凤宝 学 号 20009022384， 2009022410， 2009022427,2009022390 指导教师 张宝国 职 称 副教授 年 月 日 滨州学院专科毕业设计 (外文翻译 ) 2 Intelligent double power 1 Intelligent dual power supply switching technology In this p
2、aper, the double load - dual power automatic switching of PLC control, PLC control program to replace relay logic control circuits, it has the three-phase power supply phase detection and protection switching function, power returned to normal after the automatic reverse switch, when a fault and res
3、tore normal respectively sends out two difference clear alarm and prompt sound. Double load - dual power automatic switching control of PLC, the open-phase protection mainly adopts the technical proposal that : setting the three-phase open-phase detection signal circuit, the three-phase open-phase d
4、etection signal circuit directly from the main circuit of three-phase power supply, namely the intermediate relay KA1-KA3 and KA4-KA6, respectively connected to power supply main loop U1 and U2 A, B and C single phase circuit, KA1-KA3 and KA4-KA6 normally open contacts respectively as PLC input sign
5、al, namely as the preparation of PLC U1 and U2 three-phase open-phase detection logic control program input conditions. With short phase protection double load - dual power automatic switching control, not only has the open-phase protection, but also has a short circuit and overload protection, unde
6、r-voltage protection function； automatic phase lack detection, three-phase current display, a road power supply circuit can automatically switch to another power source to load power supply, light and sound alarm； in the power supply return to normal after automatic reverse switch； in the event of a
7、 failure and return to normal when respectively sends out two difference obvious alarm and prompt sound effects. It overcomes the shortcomings of low double power supply switching control system without phase protection, can automatically reverse switch, as well as fault and return to normal when us
8、ing a single audio prompts defects. The control system has perfect function, reliable performance, simple circuit structure, low manufacturing cost etc. 2 Intelligent dual power supplies switching main circuit control With short phase protection double load - dual power automatic switching control c
9、ircuit. It includes a main circuit and three-phase short signal detecting sampling circuit. The main circuit of the input power supply power supply U1 and U2, its output has two 滨州学院专 科毕业设计 (外文翻译 ) 3 loads W1 and W2. Power main circuit of AC contactor U1 through KM1 main contacts and a load of W1 co
10、nnected； power supply U2 main circuit through the AC contactor KM2 main contacts and a load of W2 connected； under the control of a control circuit, a power failure occurs, the AC contactor lost the first electrically disconnected, so that the load of detachment faults power supply circuit, the AC c
11、ontactor KM3 main contact closing conduction contact loop, will be connected to the fault loop load switch automatically to another normal power supply continues to supply. Power supply U1 and U2 main circuit input end of the automatic switch in QF1 and QF2 is the primary role of overload protection
12、 and short-circuit protection； two phase power supply main loop in each phase are current meter to indicate the phase current status, with the control circuit of phase lack detection. The three-phase open-phase detection signal sampling circuit, the phase detection signal directly from the main circ
13、uit of three-phase power supply, namely the intermediate relay KA1 KA3KA4 KA6 are respectively connected to the power supply main loop U1 and U2 A, B phase and C phase of the single-phase circuit, KA1 KA3 and KA4 KA6 normally open contact as U1 and U2 three-phase open-phase detection switch sampling
14、 signal, to the PLC input terminal. Considering the PLC relay output point load capacity, through the contactor KM01 KM03 to drive high current contactor KM1 KM3. For three-phase power U1 A, B phase and C phase lack detection, the use of an intermediate relay KA1, KA2 and KA3, respectively connected
15、 to power the U1 main circuit A, B phase and C phase and zero line N constitute a single-phase circuit, the formation of A1, B1 and C1 phase detection circuit. The normally open contact of KA1 KA3 as U1 three-phase. Phase lack detection switch sampling signal, to the PLC input terminal, used in the
16、preparation of PLC U1 three-phase open-phase detection logic control program input conditions； similarly, the three-phase power supply U2 A, B phase and C phase lack detection, but also the use of an intermediate relay KA4, KA5 and KA6, respectively connected to power the U2 main circuit A2, B2 phase and C2 phase and zero line N constitute a single-phase circuit, the formation of A2, B2 and C2 three-phase open-phase detection circuit. KA4 KA6 normally open contacts respectively as U2 three-phase open-phase detection switch sampling signal, to the PLC input terminal, used in the
