A Methodology for a Complete Simulation of Cyber- Physical Energy Systems Youssef Driouich Dip.to di Ingegneria dell'Informazione ed Elettrica e Matematica Applicata (DIEM) Università degli Studi di Salerno, Italy ydriouich@unisa.it Mimmo Parente Dip.to Scienze Statististiche & Innovation of Systems (DISA-MIS) Università degli Studi di Salerno, Italy parente@unisa.it Enrico Tronci Dip.to di Informatica Università degli Studi di Roma, "La Sapienza", Italy tronci@di.uniroma1.it Abstract— The number of computation cycles used for simulation-based Verification of Cyber Physical Energy Systems is outpacing the available throughput of simulation resources. In this paper, a methodology for the verification of the CPES at hand with the aim of full coverage of the system’s states is proposed. This approach relies on representing the unpredictable behaviour of the environment in order to cover all feasible possible scenarios. Processed by JModelica, the simulation results are covering the system’s complete dynamic behaviour. Simulation by complete state space covering guarantees the verification results to be sound for every possible state of the system under verification. The application to Photovoltaic circuits, specifically the Distributed Maximum Power Point Tracking, shows the feasibility of the approach. Keywords-component: Cyber-Physical Energy Systems; Simulation; Simulation-based Verification; JModelica; Distributed Maximum Power Point Tracking; Photovoltaic circuit; System Under Verification I. INTRODUCTION The complexity of the simulation models of the dynamic systems is scaling exponentially, and hence the amount of computation resource required to explore all of the states of these type of systems is scaling exponentially. As consequence, even the simplest designs of today are impossible to completely simulate. Given that simulation resources are more or less limited, the verification of each system is becoming less and less exhaustive. In this work, we consider the system modeled as state machines. Intuitively, this modeling scheme is based on the assumption that each run of the system can be described by a (possibly infinite) sequence of discrete state changes. The model then consists of a finite amount of information defining the initial state of the system, as well as all the possible state changes. A simple way of checking the correctness of such a model is to explore its state space. Harshly speaking, the idea is to check precisely all the possible situations that can arise during the possible executions of the model. For instance the works introduced in [3, 4, 5] to formalize system requirements and like those in [6, 7, 8] to define admissible operating scenarios. To this end, we present an approach for performing the state- space exploration of systems with an infinite state space with a relevant case study of Cyber Physical Energy System (CPES) for the Distributed Maximum Power Point Tracking (DMPPT) system built out of the Perturb and Observe (P&O) based Maximum Power Point Tracking (MPPT) circuit, the model of the system is presented in [9]. The paper is organized as follows: Section II presents our sys- tem’s model. Section III describes the adopted approach to ex- plore the state-space of the system at hand. The section IV gives the experimentation results. The last section offers a summary of the realised work and the future enhancement that can be accomplished. II. CASE STUDY : The models we study are primarily about dynamics, the evolution of the DMPPT [1, 2] system state in time. Our purpose is to verify if our system is able to minimize the loss of produced power when the irradiance of the panels is changing frequently in one hand, in the other hand, to check if the system converges to a desired behaviour under the actions of the controller. The system is illustrated in Fig.1. FIGURE 1: THE MODEL OF THE CPES 978-1-5386-6405-6/18/$31.00 ©2018 IEEE