Markus Mirz

The transition to Smart Grids increases the complexity of power grids by involving many more interdependent actors and integrating additional information and communications technology. To provide a common basis for Smart Grid data representation and exchange, the standardized Common Information Model (CIM) has been introduced and extended, i. a., by the Common Grid Model Exchange Specification (CGMES). An increasing acceptance by power grid operators and other actors has made CIM and CGMES more and more relevant. However, the implementation of CIM / CGMES support in software projects appears to be challenging due to the complexity of CIM / CGMES and the ongoing standardisation process with iterative adaptations. Thus, the main contribution of this paper is the presentation of a methodology for an automated generation of programming language specific code from CIM / CGMES specifications. The approach is based on the use of a template language and enables to keep software projects fully compliant with CIM / CGMES specifications. The paper outlines the process of code generation and the consecutive codebase integration for a JavaScript based CIM / CGMES web editor and for two CIM / CGMES de‐/serialiser libraries in C++ and Python. The approach is evaluated in use cases involving the visualisation and simulation of a benchmark grid.

Modern distribution grids are complex systems that need advanced management for their secure and reliable operation. The Information and Communication Technology domain today offers unprecedented opportunities for the smart design of tools in support of grid operators. This paper presents a new philosophy for the digitalization and automation of distribution grids, based on a modular architecture of microservices implemented via container technology. This architecture enables a service-oriented deployment of the intelligence needed in the Distribution Management Systems, moving beyond the traditional view of monolithic software installations in the control rooms. The proposed architecture unlocks a broad set of possibilities, including cloud-based implementations, extension of legacy systems and fast integration of machine learning-based analytic tools. Moreover, it potentially opens a completely new market of turnkey services for distribution grid management, thus avoiding large upfront investments for grid operators. This paper presents the main concepts and benefits of the proposed philosophy, together with an example of field implementation based on open source components carried out in the context of the European project SOGNO.

New types of power system transients with lower time constants are emerging due to the replacement of synchronous generation with converter interfaced generation and are challenging the modeling approaches conventionally applied in power system simulation. Quasi-stationary simulations are based on classical phasor models, whereas EMT simulations calculate the instantaneous values of models in the time domain. In addition to these conventional modeling approaches, this paper investigates simulation based on dynamic phasor models, as has been proposed by the Shifted Frequency Analysis. The simulation accuracy of the three modeling approaches was analyzed for characteristic transients from the electromagnetic to the electromechanical phenomena range, including converter control as well as low inertia transients. The analysis was carried out for systems with converter interfaced and synchronous generation whilst considering the simulation step size as a crucial influence parameter. The results show that simulations based on dynamic phasors allow for larger step sizes than simulations that calculate the instantaneous values in the time domain. This can facilitate the simulation of more complex component models and larger grid sizes. In addition, with dynamic phasors, more accurate simulation results were obtained than with classical phasors, in particular—but not exclusively—in a low inertia case. Overall, the presented work demonstrates that dynamic phasors can enable fast and accurate simulations during the transition to low inertia power systems.

Real-time simulation is an increasingly popular tool for product development and research in power systems. However, commercial simulators are still quite exclusive due to their costs and they face problems in bridging the gap between two common types of power system simulation, conventional phasor based, and electromagnetic transient simulation. This work describes recent improvements to the open source real-time simulator DPsim to address increasingly important use cases that involve power electronics that are connected to the electrical grid and increasing grid sizes. New power electronic models have been developed and integrated into the DPsim simulator together with techniques to decouple the system solution, which facilitate parallelization. The results show that the dynamic phasors in DPsim, which result from shifted frequency analysis, allow the user to combine the characteristics of conventional phasor and electromagnetic transient simulation. Besides, simulation speed up techniques that are known from the electromagnetic domain and new techniques, specific to dynamic phasors, significantly improve the performance. It demonstrates the advantages of dynamic phasor simulation for future power systems and the applicability of this concept to large scale scenarios.

This paper presents an overview of the portion of the real-time simulation laboratory of the Institute for Automation of Complex Power Systems at RWTH Aachen University, dedicated to the testing of instrumentation, measurement and monitoring applications. Its key feature is the ability to test monitoring systems and complex monitoring methods as integrated systems as well as a set of individual components. This is made possible by testing platforms that accommodate a mix of interoperable real and real-time simulated components and include communications, databases, and protocols that are representative of the field deployment of the monitoring system.