In the field of control-oriented modeling of wireless power transfer (WPT) system, it is urgent to establish a simple model to reflect the nonlinear characteristics introduced by phase-shift control methods, which is significant to the design of controllers. Due to the nonlinear nature introduced by phase-shift control, controllers designed based on specific steady-state small-signal models struggle to maintain closed-loop dynamic performance. In this article, the nonlinearities of the WPT system are implicitly considered by using the Hammerstein model-based identification (HMI) method, so the accuracy of the identified model is guaranteed even if the working point changes, which is unique advantage compared with other methods. In particular, an uncertainty model is precisely established via a frequency-domain analysis approach to introduce the nonlinear characteristics and the statistical properties of identification into the H $\infty$ control problem, which maintains the robustness of closed-loop WPT system. Finally, an experiment is given to verify the effectiveness of HMI method and proposed H $\infty$ robust controller.

With the development of distributed generation (DG) technologies, distributed energy resources (DERs) with low capacity and low inertia are highly penetrated in the islanded AC microgrid. This has highlighted the need for secondary control strategies to remedy frequency deviation and strongly limitation of the frequency synchronization rate, which are associated with the primary control. To solve this problem, an optimal condition, in terms of explicit synchronization rate formula, is derived. Then, a distributed event-triggered control strategy is proposed to synchronize the microgrid frequency to the nominal value and maximize the synchronization rate for the primary control process with time-varying load. To reduce the communication and computation burdens, an event-triggered mechanism that enables each agent to update its input based on discrete information from only one of its neighbors are provided. The stability of the event condition and event interval are also analyzed using Lyapunov method. Finally, the theoretical results are applied to a parallelfeeder test system consisting of fourteen DGs, which verifies the effectiveness of the proposed strategy.

This brief develops a novel, fully distributed cooperative control algorithm for multiagent-based ac microgrids (MGs) utilizing a low-width communication network. The proposed scheme can coordinate inverters to eliminate any deviation from the nominal frequency in battery energy storage systems (BESSs) so as to achieve optimal charging/discharging rates as well as economical operation simultaneously. Practical constraints for the charging/discharging rate, state of charge (SoC), and charge-discharge cycle are imposed to design the control protocol. Each agent is equipment with a fully distributed controller, in which only its own information and that of its nearest neighbors are acquired through low-width communication links. The global asymptotic stability condition is established using the equilibrium point theory. Several cases are studied in MATLAB/Simulink to verify the scheme effectiveness in solving the frequency synchronization and economic dispatch problems.

This paper proposes a two-layer distributed network predictive control strategy for AC microgrids (MGs) clusters with communication delays. The strategy involves establishing a twolayer communication network to regulate the voltage/frequency of all distributed generators (DGs) within the MG cluster to predefined reference values while ensuring consistency in incremental costs across individual MGs. Furthermore, a multi-step predictive controller is designed, where delay information in the controller is replaced by the latest predictions, enabling proactive compensation for delays. Stability analysis of the closed-loop AC MG clusters is conducted and the response matching condition is derived between the second and tertiary levels. Finally, realtime simulations on an OPAL-RT platform are performed for AC MG clusters, validating the robustness of the proposed control method against communication delays.

When various distributed generation (DG) technologies are integrated into an islanded AC microgrid (MG), the system's heterogeneous characteristics make synchronizing all units within the network more challenging. From the perspective of complex networks, the capability of an islanded MG to achieve synchronization is closely associated with its physical topology. Consequently, a pressing need exists for a theoretical analysis of the network topology's influence on synchronizability in AC MGs. In this article, we first develop a concise criterion for the synchronization condition of AC MGs and then introduce the definition of the synchronizability index, which measures the robustness of synchronization against disturbances such as voltage sags, sudden load changes, and component failures. Subsequently, we investigate the topology effect on synchronizability in islanded AC MGs for cases involving additional new connections or a unit node. Moreover, we provide an explicit expression of the general algorithm for computing the synchronization rate associated with topology parameters, such as the incidence matrix, weight matrix, and algebraic connectivity, among others, in the MG. The condition for the maximum synchronization rate is also explored. Finally, the accuracy of the theoretical results is validated through several test systems.