Interview with Georges Simard
In this interview, Georges Simard discusses the challenges of extending intelligence into the distribution system. He also discusses the design practices, operating techniques and technologies that will produce the smart distribution system of the future.
Question: What is the IEEE Power and Energy Society's Smart Distribution Working Group (SDWG) working on?
We're advancing design concepts and philosophies that apply to the optimization of smart distribution systems. And we're developing environmentally acceptable and technically feasible design guidelines.
This group is a forum to exchange ideas between members on smart distribution applications and technologies. We hold panel and paper sessions each year to share knowledge that will lead to writing standards for smart distribution.
One deliverable is the "Smart Distribution Application Guide," project P1854.
Two taskforces, one on volt/VAR control and the other on DMS (distribution management system) were created under the SDWG to specifically address these Smart Distribution technologies. The SDWG and the DMS and VVC task forces are among the most-attended IEEE PES distribution meetings. This shows the interest of the industry in Smart Distribution.
We maintain a website for knowledge sharing and to enable members to make active contributions. Click here for the IEEE Power and Energy Society's Smart Distribution Working Group website.
Question: What issues are you investigating as intelligence moves from generation and transmission into the distribution system?
For many people smart grid is equal to smart meters. Smart meters are a huge investment and represent direct contact with the customer. They represent a key technology for the Smart Grid. They can help make the customer aware of energy costs and the value of energy efficiency and allow utilities to optimize load control using demand response. It will be important for the customer to be involved in that.
But smart distribution is not all about smart meters. The IEEE Smart Distribution Working Group is looking at distribution systems and issues of reliability, distribution system efficiency, power quality etc... It's important to understand the behavior of legacy systems when adding new technology and applications.
As an example, going forward, more and more customer premises will become generating stations through the use of distributed energy resources (DER) or distributed generation (DG). That may impact voltage control and/or restoration schemes following an outage. So, in the future, we'll need to manage the distribution system differently.
Question: Does that imply distributed intelligence?
The industry is discussing the issue: when is it better to have central intelligence or distributed intelligence? There's no easy answer.
Think of the organization of a large company. You have a CEO, middle managers and workers. Major, strategic decisions — perhaps capital expenditures — are deliberative, slow-moving decisions made centrally by the CEO. On the other hand, you may have a very quick decision to make — for example, to trip protection relays — and this might best be done swiftly and locally.
In fact you can already see distributed intelligence at work today in a distribution recloser. These are self-contained units that see a distribution fault on the system and open and close automatically to isolate faults and minimize the impact of outages.
As distribution systems become more complex, with bi-directional flows of energy due to DERs and DGs, distributed intelligence and automation — perhaps a system installed in the distribution system equipment or in the substation — may process all that information and make a "decision." In the future, it won't be all centralized or all decentralized, it will be a mix depending on what is needed.
Question: You've written that innovation in the distribution system falls under technology, operating techniques and/or design practices. What are the issues in design?
The distribution operators and planners need to have more information from the distribution system to make better decisions. Integrating sensors and information technology into the actual equipment or the system design is required. For example, the existing design of today's switches or reclosers could be modified to include sensors adapted to the Smart Distribution requirements (more precision to achieve volt and VAR control, waveform information to pinpoint fault location, etc.). Using data from smart meters is also part of the scheme.
In the long run, some engineers envision equipment that could serve as a switch one day and a breaker the next day. Moreover, functions of the equipment have to be independent of the manufacturer for interoperability.
Using accurate distribution models (distribution system, distribution loads, control models) will be needed to design and operate a Smart Distribution system. This is a tremendous challenge because of the quantity of data involved (numbers of substation, feeders, customers) and the dynamic conditions (summer loads vs. winter loads, system reconfiguration after outages, etc.) of a distribution system.
Question: Can you describe operating techniques on the distribution system and how those are changing?
Years ago — and even today — a significant part of the distribution system is operated manually and linemen crews have to be sent to operate switches. Remote controlling of the distribution system can make it more efficient to improve reliability or to perform maintenance on the system.
Another step after the remote controlling of switches is automatic restoration and this is already happening in some areas of the distribution system. When a fault occurs on the system, the automatic restoration algorithm analyses the system through information coming from sensors on the distribution system and a new reconfiguration is proposed to feed the customers without creating overloads. The system remotely isolates the fault and restores service to the healthy part of the feeders.
Another example is voltage control. Today voltage control is achieved through a simulation to compute the voltage at the remote end of the distribution feeders, a margin is added and settings are proposed for the in-line voltage regulators or at the substation. To increase distribution system efficiency and reduce that margin in the future, smart distribution systems will feature voltage sensors and/or state estimation of the distribution system to optimize the voltage profile. Some utilities are already testing those technologies.
Question: What is the most prominent technology change on distribution systems as they become intelligent?
Distribution systems can be huge systems and they face geographical challenges. They feed cities, rural areas, and because of their differences they may apply different Smart distribution applications and technologies. This highlights the importance of the ongoing smart grid demonstration projects in the United States, Canada and other parts of the world. Utilities want to try some Smart Grid technologies in those different contexts to gauge the benefits.
When the demonstration project results on the real benefits are in, exchanges of knowledge between utilities will allow the electric distribution industry to save time and money.
I recently visited San Diego for an IEEE meeting and I was amazed at the rate at which solar photovoltaic panels are being installed on roofs everywhere. The local utility faces challenges, which some other utilities do not face at all. Obviously, some results from San Diego and the other distribution utilities facing massive DER integration will benefit other utilities that may have to face this challenge in the future.
Question: What's in it for the customer as the distribution system evolves?
People rely on electricity not only for conventional needs such as lights or heating and cooling but also for information, the Internet, and communications. So reliability will remain a major concern to the customers and as discussed, some Smart Distribution technologies will improve reliability (automatic restoration, precise fault location).
Smart meters should also help consumers understand and manage their electricity consumption and therefore manage their costs. That's a good thing worldwide, as it will reduce carbon emissions and other greenhouse gases.
Question: Do new components such as DER on the distribution system create concerns about stability?
Yes, particularly at scale. In a fully integrated system, the generating stations can be controlled when an unexpected event happens on the system (e.g. transmission line fault) and quick decisions can be made on which generating stations have to stay and which have to drop off to maintain stability. With DERs and independent power producers, it's much more difficult to maintain stability because you may not have control of all the stations and specially the small ones.
Georges Simard spent 15 years at Hydro-Quebec in distribution planning, protection and power quality, moving to in-house technical standards, Smart distribution development and roadmaps for another 15 years. For decades he has been involved with IEEE working groups and taskforces as well as the International Electrotechnical Commission (IEC) and the Canadian Electrical Association He currently leads his own firm, SIMARD Smart Grid.