Virtual impedances are often used in droop-controlled paralleled-voltage-sourced inverters (VSIs) to achieve proper power sharing. However, different and unknown output of VSIs will affect the decoupling sharing performances. To solve this problem, article proposes a novel controller for by using disturbance observer (DOB). The DOB is adopted observe currents without any extra current sensors. ...

This paper proposes a distributed control strategy that considers several source characteristics to achieve reliable and efficient operation of a hybrid ac/dc microgrid. The proposed control strategy has a two-level structure. The primary control layer is based on an adaptive droop method, which allows local controllers to operate autonomously and flexibly during disturbances such as fault, loa...

This paper presents a resilient cache memory for dynamic variation tolerance in a 40-nm CMOS. The cache can perform sustained operations under a large-amplitude voltage droop. To realize sustained operation, the resilient cache exploits 7T/14T bit-enhancing SRAM and onchip voltage/temperature monitoring circuit. 7T/14T bit-enhancing SRAM can reconfigure itself dynamically to a reliable bit-enha...

This paper proposes an efficient control framework that utilizes de-de converters to achieve flexible power flow control in multiterminal de (MTDC) grids. The de-de converter employed in this paper is connected in cascade with the de transmission line, and is therefore named cascaded power flow controller (CPFC). In this paper, a two-layer control strategy is developed for the operation and con...

Microgrids are small scale power systems with local resources for generation; consumption and storage, that can operate connected to the main grid or islanded. For the islanding operation of microgrids, two important tasks are to share the load demand and maintain the voltage and frequency stabilities. In order to achieve this goal, a hierarchical control structure can be employed. This researc...

A modern dc microgrid often comprises renewable energy sources (RESs), such as photovoltaic (PV) generation units, battery storage systems (BESSs), and local load, it is also connected to the utility grid through a point of common coupling (PCC). While most existing approaches have rely on communication links achieve desired control performance, this article proposes novel strategy without reso...

This paper deals with the problem of voltage security in microgrids. In general, voltage security is an issue for power systems, where the lack of reactive power is a concern. For microgrids a complexity is imposed, since frequency and voltage level deviations may take place by the operation of droop-controlled inverters. This paper incorporates the load margin calculation into a microgrid stru...

We demonstrate that the efficiency droop phenomenon in multiple quantum well InGaN/GaN light-emitting diodes (LEDs) may be connected to the current crowding effect. A numerical model of internal quantum efficiency calculation is presented that takes into account nonuniform lateral carrier injection in the active region. Based on this model, we examine the effect of current crowding on the effic...