Is your simulator’s electrical model meeting industry standards?
A number of historical events and recent guidelines have all pointed to the need for increased fidelity from simulator electrical models to train operators on how to respond to abnormal events. Often, simulator model updates are necessary to ensure the ability to recreate these events and subsequently train operators to make the right decisions in the given conditions.
In this post, we’ll look at four industry events / directives that are shaping new simulator functionality for electrical modeling.
Northeast Blackout
Back in 2003, a bug in one plant’s control room alarm system ultimately resulted in the forced shutdown of more than 100 power plants, cutting power to an estimated 55 million people in the US and Canada. Virtually every power plant in the Eastern half of the USA experienced frequency and voltage perturbations.
A Pacific Northwest National Laboratory (PNNL) research article, Looking back at the August 2003 blackout1, implicates situational awareness as one of the key lessons learned. The article states that various groups became aware that something wasn’t right with the grid, but that information wasn’t being shared effectively. Events progressed to an uncontrolled cascading failure when it was too late for human intervention.
To prevent a similar blackout event from occurring, plant operations staff need to be able to train on infrequently used procedures and responding to events that are often not available with simplified electrical models. Upgrading your simulator with a high-fidelity electrical model will allow the operators the availability to respond to off normal grid events, such as voltage and frequency perturbations.
Fukushima Daiichi Accident
The 2011 tsunami in Fukushima caused an extended loss of electrical power at the Fukushima Daiichi Nuclear Power Plant. The plant’s reactors automatically shut down following the earthquake, but then the following tsunami disabled emergency generators which would have been used to cool the reactors.
The NRC has determined that plants need to be prepared to withstand an extended loss of electrical power following a beyond design basis accident. The recommendation was to increase coping time from the standard 8 hours to 72 hours. One way that the industry responded was by implementing the flexible equipment strategy (FLEX) which relies on additional, portable equipment to prevent the loss of cooling capability and electrical power.
With new equipment come new operating scenarios and procedures for which your operators will need to be trained. If you haven’t upgraded your simulator with a high-fidelity electrical model, then your battery and power supply models may be over-simplified. Operators should be able to train on shifting loads and optimizing battery discharge rates on your plant simulator in order to be prepared for extended loss of electrical power events and the new plant procedures that go along with the extended coping time.
EPRI Operator Guidelines for Abnormal Generator Events
The Electric Power Research Institute (EPRI) issued its report Guidelines to Generator Operating/Maintenance Decisions Following Abnormal Operation (3002007010)2 for power plant operators to recognize and take appropriate action on unusual generator events.
EPRI outlined five areas of unusual events for power plant operators to train on in order to mitigate risk to the equipment and to improve plant safety.
- Stator-related events
- Rotor-related events
- Events affecting generator auxiliaries
- Electrical/grid related events
- Environmental/dynamic operational events
By upgrading to newer, high-fidelity electrical models, you can now train power plant operators to recognize and take appropriate action on dynamic effects such as:
- Stator cooling water flow restrictions
- Rotor ground and shaft voltage
- Loss of hydrogen seals
- Over-fluxing and off-frequency operation
- Sudden increases in vibration
Main generators are very expensive to fix, and if it’s broken you’re not putting out power, i.e. not making money! Properly training your operators on these abnormal generator events could save you millions by preventing generator failure.
NRC IN 2017-06, “Battery and Battery Charger Short-Circuit Current Contributions to a Fault on the Direct Current Distribution System,” ML17228A473
In September of 2017, the NRC issued IN 2017-06 pointing out possible design inadequacies and/or design assumptions related to battery and battery chargers in the case of downstream short circuit conditions.
Here are some things to think about as you consider IN 2017-06 applicability to your plant and simulator.
- Does your electrical system model allow DC short circuit scenarios to be run?
- Will your simulator battery chargers respond correctly to a downstream short circuit?
- Will your simulator battery dynamics respond correctly to a downstream short circuit?
- Will IN 2017-06 have an impact on the plant requiring you to make changes to the simulator to match the plant changes?
- Does your simulator meet all the needs of the operations training staff for providing appropriate training on the class 1E DC Power System at your site?
Upgrading to high-fidelity electrical models will ensure that your operations staff can train on DC power system failures.
Conclusion
The handwritten electrical models of latter day are very “logic based”. They won’t show the dynamic effects of many unusual events. As technology has evolved, high-fidelity electrical modeling software is now capable of modeling these unusual events for your plant operations staff to train on.
Talk to GSE today about upgrading your electrical model, allowing you to properly train the operators at you plant to respond to:
- Grid Perturbations and Grid Events
- Main Generator and Auxiliary System Anomalies
- Extended loss of offsite power
- DC Power System Failures
Preparing your Operations Staff to respond appropriately for these off normal events could save your company money and time in the unlikely event that it happens to you!
References
Looking back at the August 2003 Blackout. (n.d.)
EPRI: Operator Guidelines for Abnormal Generator Events. (2017, October 3).
