A000824B-DED模塊,ADVANTES使用產(chǎn)品
針對這兩點,需考量各種應用環(huán)境的應用電路設計和具體參數(shù),客戶可自行結(jié)合開關(guān)盒尺寸進行設計,但需將單火線電源的可靠性、體積、電源匹配的應用電路方案納入考慮。
基于市面上各個廠家的單火線電源產(chǎn)品的不同,其搭配的外圍電路及其電子元器件也并不相同,如模塊類的單火線電源集成度更高、IC類的單火線產(chǎn)品對客戶的自主研發(fā)能力要求較高。這里以金升陽的LSF01-K5BxxSS系列為例。后端控制系統(tǒng)為NB-loT等大功率負載的應用方案
A000824B-DED模塊,ADVANTES使用產(chǎn)品(以下簡稱:超級電容方案)。由于后端控制系統(tǒng)可能為NB-IoT等大功率負載,就需要在后端控制系統(tǒng)工作時,若單火線電源處于關(guān)態(tài),LED無“鬼火”現(xiàn)象,并且供電電壓正常;若單火線電源處于開態(tài),要求供電電壓正常,并且LED無“頻閃”現(xiàn)象。
該方案主要通過對超級電容/鋰電池進行充電儲能,提供穩(wěn)定輸出電壓給后端控制系統(tǒng)工作。由于超級電容方案內(nèi)部設計了開態(tài)和關(guān)態(tài)充電電路,故實際應用時無需因超級電容/鋰電池無電壓導致更換超級電容/鋰電池,該方案可長期正常提供穩(wěn)定輸出電壓。開關(guān)電源在應用時,可能需要輸入端的主電網(wǎng)提供短時間的大電流脈沖,這種電流脈沖通常被稱為“輸入沖擊電流”。輸入沖擊電流給主電網(wǎng)中的斷路器和其它熔斷器的選擇造成了一定麻煩:斷路器一方面要保證在過載時熔斷,起到保護作用;另一方面又必須在輸入沖擊電流出現(xiàn)時不能熔斷,避免誤動作。輸入沖擊電流也會產(chǎn)生輸入電壓波形塌陷,使電網(wǎng)的供電質(zhì)量變差,進而影響其它用電設備的工作。為確保開關(guān)電源的供電穩(wěn)定和電源本身的安全,電源應用的外圍電路設計尤為重要。
01 沖擊電流產(chǎn)生的原因
在開關(guān)電源中,輸入電壓首先經(jīng)過前級濾波,再通過橋式整流器變成直流,然后通過一個很大的電解電容器進行波形平滑,之后才能進入真正的直流/直流轉(zhuǎn)換器。輸入浪涌電流就是在對這個電解電容器進行初始充電時產(chǎn)生的,它的大小取決于起動上電時輸入電壓的幅值以及由橋式整流器和電解電容器所形成回路的總電阻。如果恰好在交流輸入電壓的峰值點起動時,就會出現(xiàn)峰值輸入浪涌電流。
02 限制開機浪涌電流的五大對策
方案1 輸入端串聯(lián)負溫度系數(shù)熱敏電阻(NTC)
*最常用的輸入浪涌電流限制方法串聯(lián)負溫度系數(shù)熱敏電阻NTC是目前為止最為簡單的抑制輸入浪涌沖擊電流的方法之一。
The upper computer needs to install dh+ board to exchange data with PLC through dh+ bus. Reformed control system
Now it is changed to ab mainstream 1756 ControlLogix5000 controller, and 1794 is used for remote iodistributed control system
, data can be exchanged between controllers through ControlNet network. The upper computer exchanges data with PLC through serial port. Improvement of control system
1 because there is not much data exchange between the upper and lower computers, the communication mode between the upper computer and PLC adopts serial port communication, and there is no need to buy expensive professional communication boards, which saves the project cost of customers.
2. The monitoring screen of the upper computer is more humanized. It is easy to input, modify and execute recipe parameters.
3 the controller adopts AB's latest ControlLogix System, which not only has advanced communication ability and the latest IO technology, but also can provide sequence, process, motion and transmission control at the same time. At the same time, Logix platform also provides general control engine, software programming environment, and hardware communication support across multiple platforms. One
programming software
All types of Logix controllers can be programmed.