Security Sessions | Models, Patrols, and Padsby Doug Houseman and Sean Morash
In the future, all of the analytics, automated restoration, transactive energy and other changes to operations will rely on one key foundation: the underlying grid model and its accuracy.
Back in the 1960’s, the grid model was a single line drawing that was done with a T-square on a drafting board. Transformers were typically denoted at the end of each lateral without regard to actual placement or connectivity to customers. After all: what more did the industry need? There were no sensors, no controls, and no generation on those circuits; phase imbalance was handled by moving a transformer from one set of connections on the feeder to another. The system was set up to build it and forget it. The model only had to be as accurate as the engineers, planners and field personnel needed.
Over the next 50 years, the industry made a large number of decisions regarding data location that did not fit in the grid model. Transformer to meter relationships went into the Customer Information System (CIS) for instance, information on assets ended up in asset management systems and so forth. The grid model was transferred into both the Geographic Information System (GIS) and the Outage Management System (OMS), and in many cases individual circuits were placed in the modeling tools like CYME and Synergy. Since there was little real-time operation, this worked well and each business area had direct control of the data they managed.
Fast-forward to the current decade and grid operations has (or will depending on where you are) changed drastically. Remote fault indicators, distributed generation, demand response and dozens of other technologies are impacting the grid. Instead of having little or no visibility beyond the substation, new meters, intelligent grid devices and distribution automation have provided lots of sensor data. The problem is that the data can be misleading if the grid connectivity, equipment location, customers served and other information in the model is wrong. Something as simple as the restoration from a car hitting a pole can change the grid configuration, especially if the pole that was hit had several services on it. Existing models tend to go out of date over time, and diligent upkeep can be time consuming and viewed as an operations and maintenance (O&M) expense to be avoided, but a pair of common modern technologies are making patrol life easier.
In the 1990’s, patrolling a line was done with a clipboard and a good pair of boots. Typically the patrol was a 4 to 5 mile per day activity, with the notes being turned in weekly and manual update being done in a few days to a few months later. In some cases, the updates had to be routed to 2 or 3 departments to have data entered into the different systems.
Fast-forward to today and technology has offered advances that mean that patrols can cover 8 to 10 miles a day and data updates can be completed within 24 hours, and in some cases in near real time. Key technology comes in two forms: small all-terrain vehicles [ATV] (ala the John Deere Gator) and pad style computing devices [PAD] (e.g. iPad, Android Pads). The ATV provides mobility and the ability to carry additional instrumentation, cameras, water and other supplies. The PAD provides the ability to see what the various existing models show and allow rapid entry of changes to the models. Obviously, field collected data should be reviewed before being put into the master data bases, but key information can flow back to engineers and planners via text messages, or emails, allowing them to ask questions before the crew moves on too far.
For example, one circuit model in a recent patrol was shown in the grid model as being secondary – beyond the distribution transformer and was displayed as a transformer on a pole. When the patrol team arrived, it was clear that the model was incomplete. The secondary was actually primary and there were 3 pole transformers at that location.
Within 10 minutes, the patrol was able to send an email, mark with GPS the locations of the 7 poles on the lateral, and the locations of the 3 transformers. By the time they had the information in the PAD, one of the engineers who was emailed asked to have the team determine the transformer sizes and take photographs of the poles in the lateral. Another 5 minutes’ worth of work was done and the inaccuracy in the model was fixed.
Prior to use of a PAD, the team had to have a laptop or carry drawings into the field to mark up. In both cases, the patrol team needed far more training in entering data. With modern PAD tools, the team member only has to touch the screen to indicate a location, or open a pull down menu. Determining accurate locations meant surveying equipment or separate GPS equipment. Now holding the PAD close to the pole or other equipment can give a GPS location automatically within a few seconds. Picture taking and review is easy. When a film based camera was used, bad pictures could only be determined after the film was developed. Now a quick look at the screen will provide an answer about is the photo showing what the engineer or planner back at the office will need to know.
A current project is looking at the first pilot set of circuits, and updating those circuits. The goal is an up-to-date grid model that can be used by the GIS, OMS, grid modeling tools, and other systems that need an accurate grid model.
Now reality has to set in: patrolling once every 5 to 10 years can help find major issues, but every storm, collision, or touch to the grid may change the model. EPRI and others are working on ways to automatically determine whether there have been changes to the grid. One method is to look at meter recorded momentaries, switching and capacitor bank transients, and other recordable changes in the voltages of the circuit.
But the ATV and PAD can cut the cost of patrols by as much as 50 percent, verification revisits by 70 percent and improve data accuracy and speed of entry significantly. While many of us worry every day about the next analytic, we all need to remember that the grid model is the base of most of our analysis.
Doug Houseman’s Holiday Wish List
Holiday lists are a tradition in much of the world. In many cases children wish for items that are not actually available, hoping beyond hope that someone will create what they want. This article is in that vein of wish lists.
Too often when doing design work on ‘future grids’ the key equipment needed does not exist yet. Some of these items are in the lab, and some are math concepts, but they all lead to new equipment that improves reliability, resiliency and hosting capacity for DER.
We can start with some simple applications of power electronics and solid state equipment with two items that would greatly increase the ability of the grid to deal with phase imbalance and improve hosting capacity.
With the typical demographics on a distribution circuit and the typical first-come, first-serve policy in most states, phase imbalance rapidly becomes an issue. So two items help fix this:
- Solid State Phase Balancer: a device that can take excess energy off of any 1 phase and transform it to match the energy on any other phase and inject the power into one or both of the other phases, allowing a physical balance of energy. There are a number of challenges with safety and operations that need to be dealt with, but this device allows continued imbalanced installation of DG beyond conventional hosting capacity.
- Solid State Tap Changers that can work on each phase differently. In some cases the voltage on one phase may need to rise, while the other two need to decline (or other combinations). The solid state tap changer allows far more operations per day than any conventional tap changer and allows rapid adjustment to voltage based on the actual production and consumption on each phase of the circuit.
The next item actually exists and a few utilities are installing them, but most are not. That is 5, 10, and 20 MVA, modular substations that are double insulated like a typical pad mount residential transformer. The nice things about designing with modular substations is that they can: be kept in stock, quick to install or replace, much lower cost, and the criticality of a modular substation is much lower. Getting to N-1 on a 100 MW does not require 2 - 100 MW substations, but rather it can be 11 – 10MW substations, increasing reliability, while reducing costs by up to 70%.
Next on the wish list: low cost sectionalizers that can be used to replace fused cutouts on a 1 for 1 basis. This will allow faster, automated restoration to more customers. Ideally the sectionalizers can operate on single phases at a time, so that if the fault only effects 1 phase, the rest of the customers can be restored.
One of the real hassles in the industry is upgrading the voltage on an existing circuit. Take a circuit that started life as 9600 volts, today it might be nice to take it to 22KV. To do that is a long, slow process and involves a huge amount of labor. What the industry needs is a portable upgrade system that allows quick changes to voltage, with minimal interruption to all customers. I have no clue how to do this, or what the technology is, but I want one.
A simple request on my list is for small capacitor banks and highly intelligent controllers that can be given a set of parameters to operate within. The capacitor bank would be segmented so the controller could turn on or off a small piece at a time, giving a much smoother operating curve and letting to be used in far more situations.
Next is an item on my list to frustrate hackers, that is a set of communications and controls that would fail useful, rather than safe. Typical IT systems fail safe, turning everything off until the hack can be defeated. In the electric grid, failing safe in the IT sense, means the hacker wins. Instead the systems need to gracefully fail in such a fashion that the remote controls turn off, but the device still delivers power. This should work on all field devices from meters and interconnects to capacitor banks and relays.
While I love the Open Field Message Bus (OpenFMB) and I think it has huge play in the industry, I want the bigger brother of the OpenFMB, The Distributed Intelligence Node, with the ability to operate based on parameters without a connection to the central location. This node would be the ultimate autonomous controller, it will need a pile of software to go with it, like DER management, Power Quality Management and other useful software. Think of it as the ultimate Nintendo Console and a pile of games to play on it. Obviously it has to fail useful, and be highly secure.
Next is a gift for my engineering and design side, which is a complete rewrite and update of the Color Books, many of them are out of date and the utilities in many cases have written internal engineering and design standards because they are out of date. New color books will take a huge amount of work, but should accelerate the next generation of the grid faster than any other single gift anyone could give the industry. It would also make training planners and engineers much faster and easier. Ideally it would come with a 20 lifetime subscription to regular updates.
The next 3 items on my list are for making the best use of renewable resources. First, is process storage (e.g. hot water and ice) to fit into existing district heating and cooling systems. This would allow excess renewable generation to be quickly stored for use later in the day. Second, is Vertical Solar Air Heaters. These simple devices can take a large amount of heating load off the grid, and provide very low cost heating to most homes. They would be installed on the south wall of most homes and smaller buildings and provide up to 100% of the heat that a home needs. The concept has been around for 60 years, but no commercial manufacturer has made real product out of the units. Third and final in this set of presents, is solar panels that are backed with a water or glycol working fluid to absorb the waste heat. In the summer the system would reduce the temperature in the solar photovoltaic system – improving efficiency and in the winter it would provide useful heat. All year round, it would provide hot water for showers and other purposes.
Finally, I want to see nano-alloys out of the university lab and into production. A number of people have demonstrated lab scale (a few millimeters) conductors that have 2 to 4 times the ability to move power as conventional conductor. Nano-copper would easily replace paper wrapped leads in tight underground situations. Being able to move far more power in existing underground ducts would help with the next generation of city power networks.
There are dozens of other presents on my Holiday wish list, from analytics to a single Grid Management System to replace DMS, ADMS, OMS and all the other MSes that the distribution system operators are now contemplating – sort of an ERP for grid control. And more and more and more and…
So, I hope Santa has room in his bag for some of my wish list. I want to see a highly effective grid moving forward, and all of these items will help.
I hope someone will read my list and take it as inspiration – creating not just what I wish for, but something much more useful.
About the Authors
As the Vice President of Innovation and Technology at EnerNex, Doug works with clients all over North America and Australia on issues related to smart grid/metering/ homes and with regulators, utilities and vendors to help move the industry to the next generation grid, and the next generation of customer relationship.
Doug has more than 30 years of extensive experience in the energy and utility industry and has been involved in projects in more than 30 countries. As a leader in grid modernization thinking, Doug was asked to author significant portions of the IEEE’s GridVision 2050 and to revise CEATI’s Distribution Utility Technology Roadmap. He is a member of the GridWise Architecture Council (GWAC) where he had a hand in both the Smart Grid Interoperability Maturity Model and Transactive Energy. Doug was named part of the World Generation Class of 2007, one of 30 people in the global utility and energy industry so named. He was the lead investigator on one of the largest studies on the future of distribution companies and in the last five years, has worked with more than 100 utilities and manufacturers, 50 governments, and five international agencies/NGOs.
As a consultant with the EnerNex Smart Grid Engineering team, Sean produces solutions through research based on a working knowledge of Smart Grid related applications, including communication technologies and protocols, advanced sensing and control, renewable energy, electrical, mechanical and information systems integration, enterprise information architecture, cyber security, information modeling, and related disciplines and methodologies. He specializes in the simplification of complex modern grid themes and systems.