Distribution Dispatch Control Center (DDCC)
Introduction of DDCC
The term Distribution Automation generally includes distribution monitoring systems, feeder automation, demand-side management, automatic meter reading, and automatic charting. TPC has been committed to distribution automation since 1992. After more than ten years of hard work, several automation systems such as distribution monitoring systems, feeder automation, and AM / FM map information systems have implemented. These systems are usually provided by different manufacturers and have different functions. Based on the experience gained from previous pilot systems, TPC has formulated its guidelines for future automation of power distribution and will continue to promote several automated feeders from 2003 to 2027 in order to provide fault detection, isolation, and restoration (FDIR) function.
At present, there are 21 Siemens systems and 1 SNC Lavalin system in operation. These systems have been implemented since 2004 and are designed to manage 22kV and 11kV distribution feeders in Taiwan.
The DDCS mainly provides SCADA and FDIR function, and has geographic map data processing capabilities, and provides complete operation screens and dispatching information for dispatchers. During an event, it can assist dispatchers to quickly resume power recovery in the upstream and downstream healthy sections. The expansion capacity provided by the system can be included in the automation range of feeders and substations in the entire area. Various types of normally open or normally closed-loop substation information terminal equipment (FRTU) and feeder information terminal equipment (FTU) installed on the site to collect data from the field. Functions of the DDCS are listed below:
(1) SCADA Function
- Monitor and control of automated switches, and devices within substation
- Map type display for electrical network topology
- SCADA provides GIS display for operation
(2) Device Location Function
- Easily navigate to required display from alarm event list, equipment tag, road name, landmark, etc.
(3) Feeder Schematic Display (SLD)
- Feeder schematic display based on electrical network topology
- Circuit Breaker status on feeder schematic display based on electrical network topology
- Circuit Breaker operation display with integrated information
(4) FDIR Function
- Automatic/manual fault location detection, isolation, upstream restoration and provide resupply switching procedures
- FDIR function can be inhibited for whole system / per substation / per feeder based on:
*Natural disaster: Inhibit FDIR for whole system
*Substation/Main TR maintenance: Inhibit FDIR for feeders under maintenance
*Faulty handling: Inhibit FDIR for faulty feeder or tag FCB to prevent close
- Simulation for fault restoration solutions
*Simulate BUS fault (Main TR fault) and calculate restoration solution
- FDCS FDIR calculation based on open loop design
*FDIR is inhibited for closed loop system
*Plan to include fault current direction determination to enhance FDIR function
(5) Database incremental update and information exchange
- Software will check the updates in OMS and export into supported format to import into FDCS database.
- Circuit breaker status in FDCS can feedback to OMS system.
(6) Various Communication Protocols Support
- ICCP communication (between DDCS and FDCS)
- FTP (OMS/DMMS and FDCS file exchange)
- NTP (Time Synchronization)
- DNP3(i) (Communication with downstream devices)
- TCP/IP (10/100/1000Mbps) and UDP (Communication with devices)
(7) Software Version Control
Tangible Achievements of Feeder Automation and Automatic Switching
According to the targets set by the Energy Bureau, TPC should complete an average of 400 automated switches for monitoring each year from 2012 to 2030. The cumulative number of automated feeders has reached 7,590 by 2019, and the penetration rate accounts for 75.22%, the number of feeder automatic line switches that have been included in the monitoring is 25,020, accounting for 46.58% of the feeder trunk switches (four underground trunk switches and overhead high-voltage load on-off switches).
The establishment of automatic switches for real-time status monitoring, remote power measurement, and remote operation can reduce manual field operations, speed up the time of resumption of electricity, reduce operating costs and improve worker safety. According to statistics, from 2007 to 2018, the number of switching operations due to power failures increased from 230 to 6,585, and the number of work maintenance operations increased from 6,493 to 54,915. In the past years, the average power outage of total users has been reduced. From 2007 to 2018, the distribution rate of automatic feeders increased from 25.52% to 73.56%. Reduced power outages per user in high-efficiency areas increased from an average of 2.67 minutes to 9.02 minutes. With automated switching, operators can immediately understand the situation and dispatch distribution feeders, quickly isolate points of failure, reduce the scope of power outages, and significantly reduce the time it takes for personnel to go to the site for repair and restore power.