Supervisory Control and Data Acquisition (SCADA) enables VEC to view real time data as to the status of equipment and other assets (open vs. closed for instance) as well as their analog values (power, voltage, current, etc.). It also allows us to remotely operate assets such as reclosers and switches.
In 2011, VEC received a $5.7 million dollar grant from the Department of Energy that facilitated the modernization and upgrade of almost all VEC substation reclosers and regulators and implementation of SCADA to over 65 locations including at all VEC substations and metering points (roughly 11,000 data points). VEC supplies much of this information to VELCO for operational and planning purposes via an Inter-Control Center Communications Protocol (ICCP) connection. These investments took place over four years and VEC was able to complete almost $11.4 million worth of projects with a 50 percent cost share with the Department of Energy.
Remote or supervisory operation allows VEC to save labor hours and reduce outage times by allowing remote switching and tagging, reducing or eliminating travel time to the field or between devices. Travel and labor hours can be reduced by eliminating trips to the field for to place monitoring devices, to perform switching and tagging for maintenance and outage restoration activities and to perform operational mandates such as voltage reductions tests or events. The overall result is shorter outages and lower costs.
Real-time monitoring (2-second intervals) provides visibility for system operations to monitor and react to events on the power system. In addition, as VEC sees more multi-direction electric flows throughout its system, the real time data provides engineering and planning with a view into the system that can be used to review system irregularities (such as voltage drops or outages) and planning analysis (identification of substation transformer upgrades or load balancing). While this data is a great asset, one of the challenges VEC faces is data validation and accuracy. The devices and relays that provide data to the Remote Terminal Units (RTUs) are not revenue grade and generally have an accuracy rate between 3-5%. This level of accuracy is adequate for high level planning but VEC continues to rely on revenue grade Electro Industries Nexus meters at its substations, some of which are connected to SCADA and others that can be accessed by cell modem, or Power Quality (PQ) recorders to review system events. There are 60 Nexus meters that provide data from substations, tie points, and several large customers. Not all VEC substations and metering points are equipped with this technology but VEC intends to continue deploying real time capable, high accuracy meters, across its system.
In addition, VEC utilizes an OSIsoft PI Historian, which archives SCADA data for use in post-mortem review of system events and anomalies as well as for system planning. VEC has built dashboards to enable mobile access to SCADA data for use by field personnel, which provides near real time visuals of the system during SCADA commissioning and during equipment maintenance.