Avista deploys distribution automation to reduce system losses and improve reliability.
Smart grid deployments come in many different forms across the United States and around the globe. Avista is addressing distribution reliability and energy efficiency because these are important issues for state governments and consumers in its operational region, the Pacific Northwest. System and customer efficiencies are still sufficient to manage peak demand. In addition, Washington state has enacted a renewable portfolio mandate, requiring utilities to meet renewable energy and conservation standards.
For years, Avista has been exploring ways to deploy supervisory control and data acquisition (SCADA) intelligence to distribution circuits and provide distribution automation. In fact, plans for a small-scale automation project were in development when the U.S. Department of Energy announced funding opportunities through the American Recovery and Reinvestment Act of 2009.
Avista was able to accelerate its project deployments with grants from the Smart Grid Investment Grant Program, the Smart Grid Demonstration Project and a work force training grant. The projects benefitting from this funding will enable Avista to bring distribution automation to 123,000 of its electric customers and advanced meters to 13,000 customers.
Like most utilities, Avista has to be notified of an outage either by a customer call-in or from a substation breaker alarm before dispatchers can begin identifying outage areas. It takes time to identify the full scope of problems, and fault locations may not be known until line patrols are conducted. Operational engineers spend time developing switching notices to help reroute power and restore power to customers. Servicemen and line crews are sent to manually operate line devices to implement the plans.
As part of Avista's smart circuits deployments, a distribution management system (DMS) will take real-time load and fault information from intelligent end devices to identify the faulted sections of a line when a circuit breaker locks open. Then, the DMS will automatically restore power upstream. Once the upstream restoration is completed, a downstream restoration plan will be created and implemented, either manually or automatically.
With the DMS, all of this can occur with no customer call-in or crews required to identify and operate line devices. Once the faulted sections are isolated, dispatchers can work on identifying repair requirements with operational crews. The result is a quicker response time, fewer customers without power and faster service restoration.
Avista is gaining system efficiencies by actively managing the reactive power flows and voltage regulator settings on its distribution circuits. Historically, Avista regulated circuit voltages with a voltage regulator on each phase. These regulators were set once every few years or once a low-voltage complaint was received. For reactive power compensation, Avista traditionally used fixed capacitor banks to help manage the voltage-ampere-reactive (VAR) flows. Circuits with large motor loads could have a switchable bank to help manage the large varying reactive load.
The DMS will implement a voltage optimization scheme that can use switchable capacitor banks to manage VAR flows in real time. As these capacitors are turned on through the course of the day, the DMS will monitor circuit voltage levels and use regulators to keep voltage at the required level. This lower voltage will help consumer appliances run at an optimal efficiency level. Avista's feeder losses will be lower, as well, by managing the reactive power flows, resulting in more efficient operations.
One of the most important aspects of Avista's smart circuits project is its approach to interoperability. Outside of the DMS, one of the core enabling technologies of the smart grid is the communications network. Done correctly, this network can support multiple applications throughout the life of the infrastructure. Avista's goal is to install communications and software that allow products to be integrated from a spectrum of vendors.
Once the wireless network is deployed in Spokane, Washington, U.S., the intent is that future applications could use the infrastructure without having to deploy a second or third network along with the network management overhead. Avista is using Tropos Networks' wireless radio network to communicate to intelligent end devices and to Itron's OpenWay meter collectors.
It also was important that the DMS and device controller be vendor neutral. That way the system could integrate the best available technologies. Schweitzer Engineering Labs' Advanced Recloser Control was used for the midline reclosers, and the switched capacitor banks used SEL Programmable Automation Controllers. In the early stages of the project, other types of devices and controllers were evaluated, but due to a lack of interoperability, they were excluded from the project.
In addition to the communications needing to be neutral, the DMS needed the ability to enable multiple applications, for example, automatic restoration, active power flow management and distributed energy resources.
To accomplish its smart grid goals, Avista concluded that a centralized DMS that could use the utility's existing outage management system (OMS) feeder topology model would be the most effective option. The DMS would have to be able to convert existing database information and integrate with the OMS to ensure an up-to-date, real-time operational model. Avista is installing the Efecac Advanced Control System as its DMS.
The devices that were going to be used for the smart circuits project needed to be field tested to validate the installation plan. Line crews and engineers ordered test devices and set them up at the utility's training facility. Each of the devices was installed, and then the designers and construction crews discussed the logistics of the work. A key result of testing was it would be more efficient to kit certain components of a device prior to field installation. That way when the time came to install the device in the field, line crews would not have to spend time in the field assembling them.
In addition to the kitting, the line operations group had a training manual produced that went over the details of installing the equipment. The manual contains images and standards drawings to help line crews effectively install the new devices. The crews were introduced to the manual in a half-day training session, in which they were able to ask questions of the design and test staff.
Outside of the construction design and implementation, another philosophical change surrounded network design and topology. Traditionally, Avista would have associated each of the devices to the substation field network. With the implementation of the automation application, field devices will regularly change the substation with which they are associated. Therefore, it no longer made sense for Avista to associate field devices with a particular substation; the devices needed to network and communicate regardless of the substation on which they were initially installed.
Implementing a distribution automation system will impact multiple business areas. The traditional operational functionalities are beginning to blur, and employees in both the craft/construction and office areas are adjusting to the changes.
One of the biggest impacts is to distribution dispatch staff who now have access to remotely controlled devices and will have to interact with an automated system once installed. Traditionally, SCADA group and system operators are the staff who have to deal with these types of systems.
The second business area impacted is cyber security. Avista has been working on critical infrastructure protection and compliance issues for years, and has growing experience dealing with security from the transmission and SCADA perspective. However, to manage security requirements for the new system, personnel need both traditional network expertise and an understanding of SCADA and transmission operations security. Avista chose to focus on strong corporate infrastructure technology skills and provide training on the operational technology.
Avista also needed to develop new policies and procedures, and train workers on the new system. To leverage existing knowledge, Avista partnered with SAIC to develop a long-term strategy for securing both the internal and external systems.
The third business area impacted is construction. Each of the traditional areas of construction now has technologies that overlap those areas. The challenge for management and craft employees is to ensure qualified workers are doing the work and that both groups are held accountable on the time and labor requirements to complete simple tasks.
Smart grid deployments require collaboration across many lines of business. Early in the smart circuits project deployments, Avista created a steering group with senior leadership from each of the business areas impacted by the project. This group is updated weekly on project status and issues so they can help the project management group resolve issues around budget and resources. Keeping leaders informed helps them make timely decisions that reduce risk in implementing the project.
In addition, the utility has strived to communicate regularly to internal stakeholders, community members and state regulatory staff. These communications give overviews of project milestones and manage expectations as to what is coming next.
Avista's smart circuits project is scheduled for completion in 2012 with the final distribution upgrades and DMS being brought on-line. The utility's ongoing commitment to improving efficiency and delivering reliable service to customers helped put Avista in a strong position to successfully leverage federal funding and implement this project. Best practices will continue to be learned along the way, which will help strengthen future projects and deliver better value for the utility and its customers.
Josh DiLuciano (firstname.lastname@example.org) is a smart grid project manager for Avista Utilities in Spokane, Washington, U.S. He coordinated and submitted Avista's Smart Grid Investment Grant application and is managing the project implementation. Previously, he was responsible for Avista's distribution automation and efficiency pilot project. In addition to grid modernization projects, DiLuciano is responsible for Avista's electric vehicle strategy and impact analysis. He is a licensed professional engineer in the state of Washington.
Efacec ACS www.efacec-acs.com
Schweitzer Engineering Laboratories www.selinc.com
Tropos Networks www.tropos.com