Volt/VAR control and Conservation Voltage Reduction as a function of advanced DMS

摘要

Volt/VAR Control (VVC) is the most desirable and cost effective application of the modern Distribution Management Systems (DMS). Integrated in DMS, built on a Distribution System State Estimator (DSE) solution as an input, and Power Flow (PF) as an optimization engine internal tool, the VVC allows the achievement of a wide variety of objectives, which can be optimized with high mathematical accuracy. However, in real systems, supporting DSE/PF models in real-time is a complicated, costly, and laborious engineering problem, which only some utilities can afford to solve successfully. Advanced Metering Infrastructure (AMI) completely changes how distribution systems are controlled in real-time. The combination of Remote Telemetry Unit (RTU) and AMI realtime measurements creates the foundation for Advanced DMS providing observability of both primary and secondary distribution. Most relevant for VVC is that it provides the capability to directly monitor voltages at customer service delivery points as required by ANSI standard. It makes possible obtaining VVC optimal solutions for different objectives, while keeping voltages as close to their limits as possible, without the need to solve the PF. The most widely used example of such VVC objective is Conservation Voltage Reduction (CVR). The paper proposes a new approach to VVC solution which combines RTU measurements with AMI voltage alarms and bellwether voltages connected to the dynamically updated topological model of the distribution grid. The approach is illustrated with a newly developed CVR algorithm that has been implemented in several utilities across the USA.