Volt/VAr optimization to enable smarter grids
Volt/VAr Optimization (VVO) is quickly becoming a frequently discussed smart grid application for the distribution grid.
VVO is an existing concept that to increase grid efficiency. Some of the key benefits include demand reduction through voltage regulation, energy loss reduction by decreasing VAr flow, and improved power quality/asset health by optimizing the power factor.
In the past, these improvements to the distribution grid have been initiated in the form of installing fixed capacitors (in all three phases) connected along the distribution lines. One feeder line of certain length might have one or two capacitor banks installed at 40% and 80% of the line length. These capacitors act as the VAr generators to boost the voltage of the feeder line around them as well as lowering the current that the line would have to carry to support the same loads. In addition, both voltage regulators and load tap changers (LTC) are often used at the feeder and substation level respectively to help maintain a consistent voltage profile.
The challenge has always been that the loads and the resulting line currents are extremly dynamic. Changes and fluctuations occur daily (day versus night loads) as well as weekly (workdays versus weekends) and seasonally (winter versus summer). With the integration of distributed energy sources such as wind and solar along with the increase in use of electric vehicles, distribution grid complexity continues to increase substantially.
Today, with the advancement of sensor, controller, communications technology, utilities can have the distribution grid between the substation and consumer at their fingertips. Sensor technology such as the SCC-125 split-core combination current/voltage transformer and line post sensors integrate accurate, reliable measurement of the primary current and voltage to allow precise switching from the controller at voltage, current, and/or VAr flow magnitudes. Coupled with communications back to the operations center, VVO is equipped to take advantage real-time visibility and control to address the increasing complexity of the grid and allow utilities and consumers to experience the benefits of efficiency improvement.
Related solutions: ABB’s Volt-VAR Management Software