Power System Co-simulation

Power System Co-simulation#

Module Overview#

Modern electric grids no longer operate as isolated transmission backbones delivering power to passive distribution feeders. Distributed energy resources (DER)—solar photovoltaics, battery storage, smart inverters, controllable loads—now interact with high-voltage dynamics in real time. Capturing this multi-scale behaviour requires a modelling strategy that respects the distinct physics, numerical formulations, and temporal resolutions of each subsystem while still representing their mutual influence. Co-simulation provides such a strategy by orchestrating purpose-built simulators through a time-synchronised data-exchange layer. In this module we use the Hierarchical Engine for Large-scale Infrastructure Co-Simulation (HELICS) to couple transmission-level dynamic analysis in ANDES with distribution-level steady-state and quasi-dynamic analysis in OpenDSS.

Module Structure#

The notebooks progress from establishing a reproducible software environment to building, validating, and analysing increasingly sophisticated transmission–distribution (T-D) studies. Along the way you will learn:

  • How HELICS manages federate registration, time negotiation, and publish–subscribe communication

  • How interface variables (boundary-bus voltage magnitude, phase angle, and net complex power) should be exchanged

  • How controller design, DER penetration, and forecast uncertainty shape system-wide performance

The final case studies mirror current research questions—for example, how feeder-level voltage regulation by smart inverters propagates to locational marginal prices, or how high-resolution solar variability influences inter-area oscillations—demonstrating why co-simulation has become indispensable for grid modernization research.

Learning Objectives#

By completing this module, you will be able to:

  • Articulate the theoretical foundations of power-system co-simulation

  • Configure HELICS federates for both static and dynamic time stepping

  • Diagnose convergence and latency problems in multi-domain simulations

  • Interpret coupled simulation results from engineering and market-operations perspectives

  • Design experiments that quantify the impact of DER scheduling and control on system reliability and economics

Prerequisites#

This module builds on concepts from earlier modules:

  • Module 1: Linux-based development workflow, environment management

  • Module 2: Python programming and scientific computing skills

  • Module 3: Optimisation concepts and electricity market fundamentals

  • Module 4: Power-flow and dynamic-equation fundamentals

Prior exposure to ANDES or OpenDSS is helpful but not assumed; the early notebooks provide concise refreshers on the command interfaces used in the co-simulation context.

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