二次回路及控制
控制系統由控制器，IO板和人機界面組成?？刂破饔扇龎K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(lián)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(gè)功率單元串聯(lián)，單元采用前側排列方式。同相的6個(gè)單元由銅排或電纜串聯(lián)并且三相的第一個(gè)單元短接成Y接中心點(diǎn)，三相的第六個(gè)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(kāi)關(guān)等，用戶(hù)二次接線(xiàn)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(gè)M8的螺釘與導軌固定。單元柜后側為水循環(huán)管路，把功率單元內產(chǎn)生的熱量帶到水-水熱交換器，由外水循環(huán)系統將內水熱量帶走。柜門(mén)內側裝有行程開(kāi)關(guān)，用于柜門(mén)連鎖，柜門(mén)打開(kāi)時(shí)將發(fā)出告警。
3.1單元柜水冷循環(huán)系統
水冷分內循環(huán)和外循環(huán)兩部分。內循環(huán)部分，變頻器功率單元采用水冷板散熱，去離子水通過(guò)管道進(jìn)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(jìn)入水-水熱交換器，水-水熱交換器通過(guò)和外循環(huán)水換熱，把熱量由外循環(huán)水帶走，冷水進(jìn)入單元水冷板繼續循環(huán)。
4.冷卻方式
據現場(chǎng)實(shí)際情況、投資、運營(yíng)、可靠性及維護成本，采用風(fēng)-水冷卻系統方案。
4.1 風(fēng)路循環(huán)
冷卻變頻器后的熱空氣由風(fēng)機從柜頂導出，通過(guò)風(fēng)道循環(huán)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(jìn)入變頻器對變頻器進(jìn)行冷卻，如此進(jìn)行循環(huán)冷卻。 s7-1200 has many novel and unique features, which will not be repeated here.
7 opinions and suggestions
What problems are found in the process of using SIMATIC s7-1200 controller and whether there are suggestions for us. Your comments and suggestions are very important and valuable to us.
As the saying goes, there is no perfect product, only better products. Objectively speaking, s7-1200 also has some shortcomings. For example, the CPU of s7-1200 has only two-way high-speed pulse output, which can not meet the needs of multi axis control. Many small devices in the market need multi axis control, so s7-1200 needs to develop more various expansion modules for supporting.
In addition, s7-1200 always starts from mb0 when defining the components of power failure holding, which requires programmers to make a very detailed plan at the beginning. It is much more convenient if the starting address of power failure protection components can be determined arbitrarily. The total number of s7-1200 power down protection is only 2048 bytes, which seems too small. The data to be protected is difficult to meet with a little more complex,
