A dynamic phasor real-time simulation based digital twin for power systems

• Ein auf Echtzeitsimulation dynamischer Phasoren basierender digitaler Zwilling für elektrische Netze

Mirz, Markus; Monti, Antonello (Thesis advisor); Benigni, Andrea (Thesis advisor)

1. Auflage. - Aachen : E.ON Energy Research Center, RWTH Aachen University (2020)
Book, Dissertation / PhD Thesis

In: E.ON Energy Research Center : ACS, Automation of complex power systems 82
Page(s)/Article-Nr.: 1 Online-Ressource (xiii, 130 Seiten) : Illustrationen, Diagramme

Dissertation, RWTH Aachen University, 2020

Abstract

Electrical power systems are becoming interdisciplinary with power electronics and more digital control algorithms entering the field. This development demands for comprehensive testing of new equipment and algorithms before deployment since power systems must be highly reliable. Pilot projects provide valuable insights but they do not offer the flexibility and reproducibility of simulation based testing environments. Hence, the concept of digital twins, an equivalent software simulation of physical assets, is becoming increasingly relevant in product development. Executing the simulation in real-time further broadens the spectrum of development stages that can be supported by simulation because the digital twin can be interfaced with hardware prototypes in Hardware-In-the-Loop experiments and with automation systems. However, the increase of power electronics introducing wide bandwidth signals and larger system sizes related to the interconnection of national power systems complicate the simulation of modern power systems in real-time. The maximum system size can be increased by running a distributed real-time simulation, which is challenging due to the small time steps required for ElectromagneticTransient (EMT) simulations typically used when considering network dynamics. An alternative is to simplify the simulation model and consider different time constants in order to reduce the required computation resources. Current simulation solutions though are highly specialized to one or few of the time constants present in power systems and the associated modelling domain, for example EMT or quasi-stationary phasors. Transferring simulation models is difficult due to the variety of modelling domains, computing technologies and input data formats. This thesis applies the dynamic phasor approach to real-time power system simulation to remove the requirement of proportionality betweenthe simulation time step and the highest frequency considered in the simulated signals. Especially for power electronics and geographicallydistributed real-time simulation, this is an interesting feature. However, the real-time execution and large scale simulation are rendered moredifficult by the increase of variables when using multiple dynamic phasors to represent a single physical signal. To address this challenge, a new power system simulator is developed in the scope of the thesis, which integrates traditional power system components and power electronics, two domains that are usually treated separately in dynamic phasor related literature. The simulator decomposes the system model into subsystems, each featuring a subset of the network nodes and the considered frequency bands. Consequently, it executes a data dependency analysis to determine a schedule for solving these subsystems and take advantage of parallelization. The scalability of the simulator is presented for models featuring a large number of electrical nodes and a wide frequency spectrum related to detailed power electronics models. Further examples demonstrate the advantage of dynamic phasors with respect to EMT simulations in terms of accuracy for larger simulation time steps. Eventually, the developed solution offers the user the flexibility to optimize for smaller simulation time steps and detailed results or large system size without having to replace models and input data of the simulation.

Institutions

• E.ON Energy Research Center [080052]
• Institute for Automation of Complex Power Systems [616310]