二次回路及控制
控制系統由控制器，IO板和人機界面組成。控制器由三塊光纖板，一塊信號板，一塊主控板和一塊電源板組成。各部分之間的聯系如下圖HIVERT變頻器控制系統結構圖所示。
圖3 HIVERT變頻器控制系統結構圖
2.變壓器柜
高壓水冷變頻器采用干式移相隔離變壓器。絕緣等級為H級。額定容量為12500kVA。
3.功率單元柜
6kV變頻器每相6個功率單元串聯，單元采用前側排列方式。同相的6個單元由銅排或電纜串聯并且三相的第一個單元短接成Y接中心點，三相的第六個單元即為變頻器的三相高壓輸出。功率單元額定電壓690V，變頻器的額定輸入/輸出電壓為6kV。正面右側為二次控制室，安裝有控制器、電源開關等，用戶二次接線端子也布置在控制室內。
功率單元采用水冷設計，安裝在導軌上，由兩個M8的螺釘與導軌固定。單元柜后側為水循環管路，把功率單元內產生的熱量帶到水-水熱交換器，由外水循環系統將內水熱量帶走。柜門內側裝有行程開關，用于柜門連鎖，柜門打開時將發出告警。
3.1單元柜水冷循環系統
水冷分內循環和外循環兩部分。內循環部分，變頻器功率單元采用水冷板散熱，去離子水通過管道進入水冷板，將IGBT等功率元件熱量傳遞給去離子水后，由去離子水帶走，進入水-水熱交換器，水-水熱交換器通過和外循環水換熱，把熱量由外循環水帶走，冷水進入單元水冷板繼續循環。
4.冷卻方式
據現場實際情況、投資、運營、可靠性及維護成本，采用風-水冷卻系統方案。
4.1 風路循環
冷卻變頻器后的熱空氣由風機從柜頂導出，通過風道循環至換熱器，換熱器中通有冷卻水，從而使空氣得以冷卻降溫，冷卻降溫后的空氣再次進入變頻器對變頻器進行冷卻，如此進行循環冷卻。to illustrate with pictures with SIMATIC s7-1200 control cabinet or products.
As the master station, cpu1214 communicates with 11 sub stations in real time through cm1241 RS-485 communication module in the figure What impact does the use of SIMATIC s7-1200 controller have on projects, products, individuals and companies.
The new generation of reflow soldering equipment of RND / rad, with SIMATIC s7-1200 as the system control core, has been introduced to the market since the spring of 2010. So far, hundreds of equipment have been in operation, and no PLC fault or bad phenomenon has occurred. The whole control system is stable and runs well, and the performance also fully meets the control needs of this series of equipment. This shows that the decision to choose s7-1200 as the control system is correct. It is believed that the good performance of s7-1200 will also create greater benefits for the company.
Through the design of this project, I will have a deeper understanding of Siemens products and have more confidence and expectations for Siemens products.
Compared with S7-200 or other brands of PLC in the same file,
