Improved Accuracy of Network Models with Grid360 DA

Apr 19, 2016

Nexant Grid360 Distribution Analytics (DA) is a web-based simulation and analysis platform designed to help utilities manage the increasingly complex changes occurring at the grid edge. The platform’s proven power flow and state estimation analytic engines leverage current data from existing smart grid and legacy utility systems -- AMI/MDM, OMS/DMS, SCADA, and GIS -- for online power system monitoring, management, and optimization. Complementing these capabilities, Grid360 DA also offers improved accuracy of network models.  By providing a computational estimate of the current state of the power system through advanced state estimation tools for both balanced and unbalanced networks, utilities can easily find and resolve discrepancies between estimated and measured data, potentially caused by a variety of factors, including inconsistent measurement data; erroneous load, conductor, and/or device data; or incorrect topology or switch states.

Working with geospatial and engineering data from utility systems to display transmission, subtransmission, and distribution networks on a geographic map and in schematic views, utilities are able to run state estimation analytics and visually identify observable islands as well as “problem areas” based on inconsistent data reports. The reports compare actual, real-time measurement values versus estimated values (based on the state of the network and other measurement data) of a device or line over a period of time. For example, the screen shot below illustrates the gross measurement error and the residual difference or deviation between values; that is, the line segment highlighted below is estimated to be 0.80 MW for Phase C but is actually loaded at 0.12 MW, equaling a difference of -0.66 MW.

Beyond the real versus estimated measurement values, the reports designate the measurement types, which include active / reactive power and current injections, flows, group flows (branch or zone), voltage magnitudes and angle differences, and transformer taps and phase shifter angles. The reports also show the devices and lines where the erroneous data is occurring as well as the bus section and substation to and from which the branch flows.

From here, users can quickly begin to investigate why the error exists and determine a path toward resolution. The user may discover that inconsistent data is caused by an issue with a conductor or load point, an inconsistent maximum/minimum voltage setting, a faulted AC line, an incorrectly modeled switch status, a measurement associated with the wrong location in the network model, connectivity errors in the network model, data errors (such as incorrect phase or conductor length), or a variety of other reasons.  

Reporting on erroneous measurements and inconsistent data allows distribution engineers, planners, and operators to easily identify, investigate, and resolve these discrepancies. This results in a more accurate network model, which serves as the foundation for numerous advanced smart grid analytics. In addition, by providing users with analytical capabilities and reports so they can determine where the network should be optimized, Grid360 DA helps utilities minimize system losses, reduce operational expenses, and improve overall system efficiency. Also, by keeping the supply voltages and power flows within prescribed limits, Grid360 DA can better improve network resiliency and enable utilities to comply with regulatory mandates. Consequently, Grid360 DA is the advanced analytical system for the forward-thinking utility.