In this article, a broad overview of the current research trends in power-electronic innovations in cyber–physical systems (CPSs) is presented. The recent advances in semiconductor device technologies, control architectures, and communication methodologies have enabled researchers to develop integrated smart CPSs that can cater to the emerging requirements of smart grids, renewable energy, electric vehicles, trains, ships, the Internet of Things (IoT), and so on. The topics presented in this article include novel power-distribution architectures, protection techniques considering large renewable integration in smart grids, wireless charging in electric vehicles, simultaneous power and information transmission, multihop network-based coordination, power technologies for renewable energy and smart transformer, CPS reliability, transactive smart railway grid, and real-time simulation of shipboard power systems. It is anticipated that the research trends presented in this article will provide a timely and useful overview to the power-electronics researchers with broad applications in CPSs.

In the last decade, the development of next-generation electrical smart grids (ESGs) has been one of the priorities in the field of electrical engineering, both for most of the research centers and for the industry. In short, an ESG consists of the integration of information technologies into the electrical system to improve its controllability. In traditional power systems, the control has been carried out only by the power plants and some elements of the grid (transformer tap-changers, compensation capacitors, and reactances), whereas, in the next-generation smart grids, most of the elements can respond to control orders from the system operator, which allows, for instance, for the integration of the distributed generation and the demand into the control schemes of the power system. Because of this improved controllability, ESG technologies promise a significant improvement in the capacity utilization, the reliability of the system, and the energy efficiency of the grid.

This paper presents a proposal to modify power supply systems currently used in ac-fed railways with neutral zones (NZs), in order to allow power-flow routing. The proposed system complements the existing infrastructure with additional power-electronic devices connected in parallel to both sides of the NZs, allowing control of power flow through adjacent electrical sections. The description and control of such a modified railway system is outlined in this paper. In addition, a mixed-integer programming optimization problem is formulated, which minimizes the investment and the operation costs, while ensuring the power supply to the train traffic. This optimization model is used to allow a systematic evaluation of the benefits of implementing such a railway smart grid system. Finally, a section of the high-speed line between Madrid and Barcelona is used as a case study, and the advantages of the proposed system are quantified in two different scenarios.

This paper presents an equivalent model that allows representing bi-voltage autotransformer-based systems (such as 2 × 25 kV ac, 2 × 15 kV ac) as if they were monovoltage systems. This model can be used for symmetrical (such as 2 × 25-kV 50-Hz systems) and unsymmetrical (such as 12/24-kV 25-Hz systems) configurations. It is based on two simplifying hypotheses that establish relationships between currents and voltages in the positive and negative phases. These hypotheses are discussed and the accuracy of the model is evaluated by comparing the results with a detailed conventional model of power-supply systems.

Stability analysis of micropower networks is gaining importance given the dwindling gap of power generation and demand as well as increasing penetration of intermittent renewable energy sources. Instead of using prevalent small-signal analysis-based approaches, with predictions typically limited to the vicinity of the equilibrium, the outlined approach provides a sense of global/semiglobal stability. With regard to the latter, current approaches to stability analysis are primarily based on time-domain-, energy-function-, and common-Lyapunov-function-based analyses. This paper outlines a stability analysis approach based on polynomial Lyapunov function, which is determined algorithmically using sum-of-squares optimization in order to maximize the region of attraction (ROA) of an equilibrium solution. This procedure precludes the need for prior knowledge of the form of the Lyapunov or energy function. In this paper, the tradeoff between accuracy of determining the ROA of a power-system model and the computation overhead incurred is evaluated.