Background

The coupling of engineered systems and markets impacts broader and broader areas of the electric power industry. Energy trading products cover shorter time periods and demand response programs are moving more and more toward real-time pricing. Market-based trading activity impacts ever more directly the physical operation of the system and the boundaries of these coupled systems extend beyond the traditional boundaries of utility-centric energy system operations. To address the gaps in our simulation capabilities, the US Department of Energy is developing GridLAB-D at Pacific Northwest National Laboratory in collaboration with industry and academia. This is the first of a new generation of power distribution system simulation software.

GridLAB-D combines end-use and power distribution automation models with other software tools, resulting in a powerful tool for power system analysis capable of running on high-performance computers. It is a flexible simulation environment that can further be integrated with a variety of third-party data management and analysis tools.

At its core, GridLAB-D has an advanced algorithm that can determine the simultaneous state of millions of independent devices, each of which is described by multiple differential equations solved only locally for both state and time. The advantages of this algorithm over traditional finite difference-based simulators are: 1) it is much more accurate; 2) it can handle widely disparate time scales, ranging from sub-seconds to many years; and 3) it is easy to integrate with new modules and third-party systems. The advantage over traditional differential-based solvers is that it is not necessary to integrate all the device's behaviors into a single set of equations that must be solved.

At its simplest GridLAB-D can examine in detail the interplay of every part of a distribution system with every other. GridLAB-D does not require the use of reduced-order models, so the danger of erroneous assumptions is averted. GridLAB-D is more likely to find problems with programs and business strategies than any other tool available. It is therefore an essential tool for industry and government planners.

See Current Status for more up-to-date information.