This paper presents a cooperative control which is applied to the secondary control of a microgrid controlled via a multi-agent scheme. Balancing power that leads to voltage and frequency stability in a microgrid is essential. The voltage and frequency regulations are limiting within the specified limits and conveying them to their nominal values. Limiting and conveying the voltage and frequenc...

Nitride-based light-emitting diodes (LEDs) suffer from a reduction (droop) of the internal quantum efficiency with increasing injection current. This droop phenomenon is currently the subject of intense research worldwide, as it delays general lighting applications of GaN-based LEDs. Several explanations of the efficiency droop have been proposed in recent years, but none is widely accepted. Th...

The effect of strongly-imbalanced carrier concentration and mobility on efficiency droop is studied by comparing the onset voltage of high injection, the onset current density of the droop, and the magnitude of the droop, as well as their temperature dependence, of GaInN-based blue and green light-emitting diodes (LEDs). An n-to-p asymmetry factor is defined as σn/σp, and was found to be 17.1 f...

This paper addresses voltage control and load sharing in DC distribution systems. At present, DC distribution systems are utilised in, for example, telecommunication systems. Future applications could also involve distributed power systems based on renewable energy sources. The dynamic and stationary properties of voltage droop control and its load sharing abilities are investigated. The DC bus...

microgrids are small-scale, low voltage (lv) power networks which employ renewable distribution energy resources (ders) with power electronic interfaces (peis). microgrids as single controlled units and active distribution networks require flexible control systems to ensure reliable and secure operation in different modes. these various operations of microgrid cause variations in voltage and fr...

Nitride-based light-emitting diodes (LEDs) suffer from a reduction (droop) of the internal quantum efficiency with increasing injection current. This droop phenomenon is currently the subject of intense research worldwide, as it delays general lighting applications of GaN-based LEDs. Several proposals have been forwarded to explain the efficiency droop. Among the suggested droop mechanisms are ...

In this paper, a distributed synergetic control based on multi-agent systems is proposed to solve the problems of frequency and voltage errors, system stability and power sharing accuracy in the traditional droop control of microgrids. Starting with power flow equations, we build the secondary-order dynamic model of DG, which consists of three parts: (1) active power allocation; (2) active powe...

In this paper, we propose a method for automated di/dt stressmark generation to test maximum voltage droop in a microprocessor power distribution network. The di/dt stressmark is an instruction sequence which draws periodic high and low current pulses that maximize voltage fluctuations including voltage droops. In order to automate di/dt stressmark generation, we devise a code generator with th...

This paper is concerned with the control strategy for the parallel operation of distributed generation systems (DGS) in a standalone AC power supply. The proposed control method uses only low-bandwidth data communication signals between each generation system in addition to the locally measurable feedback signals. This is achieved by combining two control methods: droop control method and avera...

In this paper, a simpler implementation of the well-known droop method for the control of parallel Uninterruptible Power Supply (UPS) systems is presented. In this method, in the power-sharing control scheme, the output current is calculated by software without the need for a current sensor, resulting in a simpler and cheaper structure. By doing so, the number of feedback sensors is reduced fro...