FTU Power Solutions in Electric Power Industry


 Abstract In the electrical power industry, equipment such as RTU*, DTU*, FTU* and TTU* are switch monitoring devices installed in the substation close to the feed breakers (a disconnector which is located in series at the end of a feeder , within a substation bay, in order to isolate the feeder from the system) , which is widely suitable for use in automation engineering applications, urban, rural or enterprise power distribution networks. These can be used for automated functions such as monitoring, protection and communications in a ring network cabinet in the distribution substation and master station with the implementation of monitoring and fault identification, isolation and power recovery of the fault in the distribution network. The internal structure and design is very similar to power supplies. 
[1] RTU: Remote terminal unit 
[2] FTU: Feeder terminal unit 
[3] TTU: Distribution Transformer supervisory Terminal Unit 
[4] DTU: Data Transfer unit.

The chart above shows that FTU monitors three phase current, voltage and binary signal by way of data analysis. The power supply requirement is as follows: 

• Employing a UPS (Uninterruptable Power Supply) by inserting a dual power supply for switched power and automatic battery switching. 
• DC-DC converter with the ability to work within a wide input voltage range caused by the charge and discharge from battery banks. 
• DC –DC converter must be compatible with both 24V and 48V battery voltage input. 
• High 3KV isolation voltage of the power supply can isolate the interference away from the AC end of the primary power source. 
• System power break time remains more than 500 ms when the power supply and the battery power supply disconnects.

To satisfy the above requirement for a power supply , Mornsun has recently released their URF_LP-20W series which is a 20W 3000VAC high isolation range of DC/DC converters . Featuring: 
• High efficiency 
• Wide Operating temperature between -40℃ to 85℃ .
• Wide 4:1 (18~75V) input which suits both 24V and 48V battery input voltages. 
• Isolation voltage up to 3000VAC can isolate interference introduced from the battery charging side. 
• Design meets EMC - CISPR22 / EN55022 CLASS A