Power grid: modelling and simulation key to security, reliability and efficiency

Paul Boughton
A new US report concludes that detailed simulations of how electric power is supplied and transferred around the country will bolster grid security, reliability, efficiency and resilience. Sean Ottewell reports.

Last December the US Department of Homeland Security and Science held a two-day workshop to explore whether current electric power grid modelling and simulation capabilities are sufficient to meet known and emerging challenges.

Its findings have just been published in the new report National Power Grid Simulation Capability: Needs and Issues (see http://www.anl.gov/ese/pdfs/PowerGridBrochure.pdf).

The workshop, which was hosted by Argonne National Laboratory, brought together 40 power system and modelling experts from federal agencies, the national laboratories, and academia.

At issue was whether a national power grid simulation capability could fill gaps that exist between today's efforts and the needs of decision and policy makers. The workshop identified barriers that a national grid simulation capability would need to overcome to be effective.

Grid behaviour

The new report notes that modelling and simulation provide a computerised representation of the behaviour of the grid system. They are used for developing an understanding of the interaction of the parts of an electric grid and of the system as a whole. They are an integral part of management, planning, and stewardship of the grid system.

As such, modelling and simulation are used by a diverse set of stakeholders for a diverse set of applications, including operations, planning, training, and policymaking.

Despite the many ongoing quality electric power grid modelling projects, individual projects have been narrow in scope and have not provided an integrated, comprehensive capability.


As a consequence, the workshop participants concluded that current efforts and capabilities at universities and national laboratories are inadequate for addressing important national-scale grid challenges, including:

- Wide-area disruptive events, including natural events, cascading accidents, and co-ordinated cyber and physical attacks.

- Interdependencies of the power grid system and critical infrastructures.

- Improvement of existing simulation methods.

- Planning and design scenarios for the power grids, including wide-scale deployment of intermittent, distributed generation.

Understanding the interdependencies of the electric power grids with other critical infrastructures, in particular, represents a serious unmet need.

Disruptions in one infrastructure (such as the electric grid system) can have severe consequences for other infrastructures (such as the natural gas and water supply systems).

Modelling and simulation are needed to understand the full impact of a regional or national-scale incident and would help improve recovery measures (Fig. 1).

Resilient infrastructure

A national power grid simulation capability would be a key element toward filling these gaps to help ensure a resilient US electric infrastructure.

Such a capability would provide an advanced, scalable simulation environment that is open to federal, state, municipal, and industry users. It would provide an advanced user environment to simplify data and model integration, scenario construction, analysis, and report generation.

The capability would be a resource for users akin to a Department of Energy user facility. In this sense, this would not be a project with specific deliverables, but a capbility from which projects can be implemented.

A national power grid simulator capability would focus on US electric power grid modelling and simulation with connections to other critical infrastructures, such as transportation, oil and natural gas, water supply, and communications.

Such a capability would provide a simulation framework and suite of integrated simulation tools to support needs for security, reliability, and resiliency of the national power grids.

High-fidelity simulation

The system would provide, for instance, a high-fidelity simulation environment for testing new models and evaluating the grid system's performance and would help decision makers balance priorities for incident prevention and recovery.

New modelling approaches could span diverse applications (operations, planning, training, and policymaking) and concerns (security, reliability, economics, resilience, and environmental impact) on a wider set of spatial and temporal scales than are now available.

A national power grid simulation capability would aim to support ongoing industry initiatives and support policy and planning decisions, national security issues and exercises, and international issues related to, for instance, supply chains, interconnectivity, and trade.

Such a capability does not exist today. A new initiative could fulfill this role, but would require a unique set of attributes:

- A multi-scale, multi-data, multi-user, multi-model system in a user-focused collaboration venue that allows coordination and interaction among users and stakeholders.

- Continuous improvements and capability enhancement.

- Flexible teaming and alliances.

- Multidisciplinary tool-development teams.

For a national power grid simulation initiative to be effective, additional requirements would need to be met, including:

- Industry buy-in for the initiative.

- Co-operation among various government agencies responsible for grid operations, oversight, development, and security;

- Access to multiple levels of data, including possibly real-time data;

- Protective data sharing and legal measures associated with data and model access;

- Validation of some model results with industry co-operation and support.

These features can be met through a combination of existing distributed capabilities and new capabilities. Defining the details of these needs will require further study.

Infrastructure data

Several issues would have to be addressed in developing and implementing a national power grid simulation capability. In particular, acquisition of and access to validated electric infrastructure data would be a necessary part of a grid simulator initiative.

Physical and administrative protection of controlled information would, of course, be essential, including protection of sensitive information generated as model output.

Additional issues related to data, models, computation, and result quality control are also highlighted in this report. Despite these issues, a national power grid simulation capability would provide many benefits, especially as the grid system faces new and growing challenges.

In particular, a national power grid simulator would provide the opportunity for data sharing, data verification and validation, identification of data use, and an environment that simplifies the integration of diverse system models.

A power grid initiative could also provide a template for eventually addressing a wider set of national issues such as water and waste water, communications, transportation, and other critical infrastructures.

For these reasons, all of the participants of the National Power Grid Simulator Workshop recommend a fruther, more detailed study of the barriers which are currently inhibiting the development of a national grid simulation capability. An operational plan that overcomes these barriers would set the stage for the implementation of a capability that would go far in supporting a more secure and reliable electric power grid system for the nation.

Engaging industry

A near-term step would be to further engage the electric power industry to better understand their needs, capabilities, and concerns, says the report.

"Modelling and simulation have proved to be effective tools for the power industry on many levels," said Mark Petri, Argonne's technology development director and one of the workshop's organisers. "We need to develop a comprehensive and integrated approach that will enable us to better understand the full implications of an evolving power grid as we plan for future demand and power sources."

However, he cautioned: "Implementing smart grid technologies on a large scale will not be trivial. The challenges go beyond technical and economic issues. The smart grid technologies could fundamentally change how national power grid systems operate and respond to disruptions."