QUESTION
Can we do Automation Control with PME for
Devices:
- 1xSepam80
- 1xMasterpact 1600A
Required functions:
- We want to switch off automatically in any event of interference/deviation/alarm.
- We want to switch on automatically after some of the events above.
- We want the possibility to switch on manually/remotely.
Which is the easiest way to solve the above requirements?
ANSWER:
This is a question about Automatic Distributed Control of Power breakers with Power Monitoring Expert.
1.Application characteristics
There are few arguments that allow us to classify the Automation of a Power Circuit breaker as a time critical process. Few of these arguments are:
- A power breaker is used not only to switch on/off a power line with or without Voltage but mainly to brake the current in case of o Fault produced on Power Network.
- The value of a fault current into power Network is increasing in an uncontrolled way, very fast, in lower than 400ms, to the highest value which is dangerous for Network.
- Operation time of a power breaker is and should be lower than 100ms as to minimize as much as possible the damages in case of a fault.
- A power breaker should be able to close on a certain fault without suffering any damages and trip very fast in that case. Each breaker is designed and able to perform recloser function and it is tested for by operation cycle specified by IEC standard. During such recloser cycle the operator should be able to monitor the breaker status in real time and Automation system should not have any delay in performing the control actions.
- There is a need for a high safety degree on power network in any case of status change.
- Monitoring the status of the power breaker in such cases should be very accurate and in real time, without any delay or error.
2.Devices capabilities
Sepam 80 is a digital protection Relay (Intelligent Electronic Device) which has the function of Distributed control for Circuit breaker as own feature implemented to satisfy above arguments and more other high performances of Automation process.
Depending of application where it is used, Sepam 80 can perform Automation Control of power breakers on Low Voltage and high Voltage networks and it fulfill the conditions of automation of time critical processes.
Sepam 80 has an additional Automation programming feature named Logipam which can be used to implement complex Distributed Control application. It add to Sepam 80 a plc type function and a programming language that help to implement Control application.
Masterpact 1600 A is a power breaker used in Low Voltage Power Networks. It has own features to perform the requests of time critical application for which is used.
Both devices, Sepam 80 and Masterpact are designed to be integrated into Distributed Control Automation Systems.
3.Software capabilities
Power Monitoring Expert has the features to implement Distributed Control Automation.
- Vista, Real time user interface diagram with animated objects used to send Control and to monitor the status of controlled objects.
- Designer, programming interface where ION Modules Control Objects a used to implement automation and control function on specific devices.
- Virtual ION Processor, a programming application where ION Modules Control Objects are used to implement Distributed Control Automation over a network of objects.
4.Conclusions
For some specific reasons like a delay between sending control action and monitoring the status change of the controlled object (the refresh time of a status object in Vista diagram is higher than 1 second), Power Monitoring Expert is suitable only to implement Distributed Control on slow processes or for processes where time and safety are not critical.
Power Monitoring Expert is not designed for Distributed Control of processes where time and safety are critical as they are mentioned above to Application characteristics paragraph.
This aspect is mentioned in many places into StruxureWare Power Monitoring Expert 8.2 User Guide, reference 7EN02-0391-00, and is pop up when user open Designer-VIP and Vista. The message from User manual is reproduced bellow:
5.ADVICE
As a matter of facts, the requested functions mentioned into Question on this documents, are possible to be implemented in PME but because of reasons mentioned at point 1 the correct advice is:
do not use Power Monitoring Expert to do Distribution Control with Sepam 80 and Masterpact dedicated:
- to switch off the power breaker automatically in any event of interference/deviation/alarm.
- to switch on the power breaker automatically after some of the events above.
- to switch on the power breaker manually/remotely.
To perform requested Automation functions the better is to use specific Sepam 80 Control functions with Logipam or use a SCADA system software and a PLC.