Arc Mitigation Program based on IEC 61850 for Switchgears
2006 – I was working for Switchgear manufacturers called Gulf Power Distribution Works Lmtd, (GPDS), located in Dammam, Saudi Arabia. GPDS was the approved manufacturer of switchgear for Saudi Aramco, an oil and gas company. Back then, the Saudi Aramco standard did not require arc-proof switchgear. This was a huge safety issue for Aramco engineers and technicians, which ended up resulting in several fatalities. Aramco was hesitant to replace the non arc-proof switchgears with arc-proof switchgears as these switchgears were already energized in oil and gas plants. They were looking for a long term solution because they could not afford to shut down the oil and gas facilities. They also did not want to change the existing protection control scheme.
I proposed two options:
1) To install new arc flash relays, and arm switches in order to clear the fault in minimum time.
2) To control the breakers and monitor the power parameters from remote control cabinets, located 30 ft away from the arc-flash zone but within the building
Saudi Aramco ended up accepting option 2 as it required minimum modifications in the existing control protection scheme. It was also the more economical option for the company because it resulted in minimum shut downs. Saudi Aramco awarded GPDS with a contract to implement option 2, allowing them to modify seven substations. Two of the substations were located in the Riyadh refinery and five of them were located in the Yanbu refinery/NGL plant.
The existing switchgear was 115kv/13.8kv/4.16kv/480v and the total number of breakers was 250.The 115KV switchgear was gas insulated, while the others were vacuum breakers.
Option 2 required modifications in two parts:
1) Switchgear close/Trip control circuit modification
2) Design/development of the remote control circuit breaker system cabinet
Saudi Aramco required the following commands and status for each HV/MV breakers:
· On/off Command, Open/close/trip/rack in/out status, and metering data
We developed the complete I/O list for each substation switchgear line up.
We modified the existing close/trip circuit by using a new selector switch in parallel with the close/trip control circuit of each feeder. Please see the modified control circuit drawing for one typical feeder below.
Riyadh Refinery Typical modified Circuit
We used circuit breaker cell auxiliary switch spare contacts ( Mechanism operated contact MOC) and other circuit breaker cell auxiliary switch spare contact (Truck operated contacts TOC) to monitor the following statuses: open/close/ rack in/rack out.
The ion metering devices 7600/7650 were installed on each bus of the switchgear.
We daisy-chained all the meters of each bus as the protocol were operating on Modbus, and we connected all these daisy-chained meters to Vizimax Righwon Gateway. This gateway converts Modbus protocol to IEC 61850. There were spare ports available on these meters, so we wired Lockout relay spare contacts to these ports to get Circuit breaker trip status. The On/off command were issued using SEL 2440 high interrupting gateway contacts , Via zenon software. We also used the subnet Canada substation server to communicate with the Saudi Aramco master control center, operating on GE harries 6000 & DNP 3 protocol.
Remote control Circuit breaker panel consist of following major components.
We used Copd data Zenon Energy edition IEC 61850 software to develop the HMI and configure process all commands and status
Following are the major hardware component .All component must compaly to IEC 61850
Ruggedcom Canada IEC 61850 compliant managed switches
SEL 2440 ( Discrete Programmable automation controller DPAC) Gateways converting DI/DO signals to IEC 61850
Vizimax Rightwon gateway converting Modbus RTU to IEC 61850
Subnet Canada server Converting IEC 61850 to GE Harris 6000
NTP server time synchronizing clock
ELIO 19 inch touch screen rack mounted
Moxa 683 IEC 61850 compliant rack mounted industrial computer
Copa Data Austria Zenon Energy Edition IEC 61850software loaded on Moxa 683
Fiber Optic Patch panels and patch Chords
These component were assemble in Control Cabinet and all the engineering design and test was by Gulf Power Distribution Systems works Limited (GPDS)
GPDS was First switchgear manufacturer to develop to develop and implement Arc mitigation program for existing non Arc proof switchgear.
Remote control cabinet /Architect diagram/HMI Snap shots
We installed the remote control circuit breaker cabinet and laid control and power cables between switchgear and remote control cabinets. We uploaded Zenon Energy edition on the Moxa 683 computer, developed HMI control commands .We tested the following:
On/off command, open/close/trip/rack in/rack out status, power parameters, critical alarms, and sequence of events
We achieved the remote control of breakers by controlling the breakers away from the arc flash zone within the switchgear building from the control cabinet touch screen and from the Saudi Aramco master control station with minimum shutdowns, therefore enhancing the safety requirement for Saudi Aramco operating staff in seven substations.
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