簡介
Closed Transition Transfer Switch (CTTS)
CTTS(閉路過渡式)轉換開關
In a typical emergency system, there is an inherent momentary interruption of power to the load when it is transferred from one available
source to another. In most cases this outage is inconsequential, particularly if it is less than 1/6 of a second.
在一個典型的應急系統中，一個正常運行的電路通常會發生內部暫時的電源中斷。絕大多數情況這種暫時的中斷無足輕重，特別是當時間小於六分之一
秒時。
There are some loads, however, that are affected by even the slightest loss of power. There are also operational conditions where it may be
desirable to transfer loads with zero interruption of power when conditions permit. For these applications, closed transition transfer
switches can be provided.
當然會有一些負荷受任何微小的電源中斷都會有影響。也有一些操作環境要求當條件允許時，某些負荷需由不停電電源供電。只有在這些套用中，CTTS
才有使用的必要。
When transferring loads in this manner during a test or when re-transferring to normal after power is restored, the switch will operate in a
make-before-break mode provided both sources are acceptable and in synchronism.
當電源恢復正常後，在測試狀態下或正在以這種方式供電的負荷恢復正常時，在“make-before-break”（“動作於中斷前”）模式下的開關就會動作
，同步恢復雙路供電。
Typical parameters determining synchronism are: voltage difference less than 5%, frequency difference less than 0.2 Hz, and relative phase
angle between the sources of 5 electrical degrees.
決定同步動作的典型參數有：電壓差小於百分之五，頻率差小於0.2赫茲，相對相位與電源電角度相差在5度。
Since the maximum frequency difference is 0.2 Hz, the engine will generally be required to be controlled by an isochronous governor.
如果最大頻率差大於0.2赫茲，那么同步控制器就會控制發電機啟動。
It is generally required that the closed transition, or overlap time be less than 100 milliseconds. If either source is not present, or not
acceptable, such as when normal fails, the switch must operate in a break-before-make mode (standard open transition operation).
裝置的閉路開啟及重疊時間通常回響小於100毫秒。如果其中任何之一的電源不存在或者不合適，諸如常用電源中斷，處在“make-before-break”（
“動作於中斷前”）模式下的CTTS切換開關都會動作。（“make-before-break”，標準的開啟傳輸切換）
Closed transition transfer makes code-mandated monthly testing less objectionable because it eliminates the interruption to critical loads,
which occur during traditional open transition transfer.
由於忽略了對重要負荷的電源中斷，CTTS開關使得原來每月的逐條測試變得不那么令人反感。
其他
韓國漢薩株式會社生產製造的HANpro2000 和HANpro3000（最新產品）由上海韓發電氣有限公司負責在中國銷售。
