With the rapidly increasing number of distributed energy resources (DER) on electric grids worldwide, there is a growing need to have these devices provide grid services and contribute to voltage and frequency regulation. PV inverters and other reactive-power capable DER have the capability to minimize distribution losses and provide voltage regulation with grid-support functions such as volt-v...

The installation of stationary super-capacitor energy storage system (ESS) in metro systems can recycle the vehicle braking energy and improve the pantograph voltage profile. This paper aims to optimize the energy management, location, and size of stationary super-capacitor ESSes simultaneously and obtain the best economic efficiency and voltage profile of metro systems. Firstly, the simulation...

in this paper, the concept of conjectural variation (cv) is used to specify optimal generation decision for generation companies (gencos). the conjecture of genco is defined as its belief or expectation about the reaction of rivals to change of its output. using cv method, each genco has to learn and estimate strategic behaviors of other competitors from available historical market operation da...

The performance analysis of the two-stage CMOS operational amplifiers employing Miller capacitor in conjunction with the common-gate current buffer is presented. Unlike the previously reported design strategy of the opamp of this type, which results in the opamp with a lower power supply requirements, better phase margin and better speed. The Opamp is designed to exhibit a unity gain frequency ...

The photovoltaic (PV) system exhibits a nonlinear current-voltage (I-V) characteristic that its maximum power point (MPP) varies with solar insolation and temperature. In this paper, a maximum power point tracking (MPPT) method using fuzzy logic control (FLC) is presented. This method is based on the concept of perturbation and observation (P & O) algorithm to track the MPP. The two stage grid ...

This paper mainly studies the main circuit topology, the working principle, modulation technique and control strategy of the STATCOM based on H-bridge. The STATCOM direct power control algorithm based on the virtual flux is used to control the AC side reactive power compensation, and in accordance with the principle of conservation of power, the DC side voltage imbalance factors are analyzed, a...

This paper considers the joint optimal design of CEOs’ on-the-job compensation and severance pay in a general optimal contracting framework. We obtain a novel argument for high-powered, non-linear CEO compensation such as bonus schemes and option grants that is different from existing arguments based on moral hazard and risk taking. Based on this argument, the CEO’s optimal on-the-job compensat...

Reactive energy and power factor L2 1.1 The nature of reactive energy L2 1.2 Equipment and appliances requiring reactive energy L2 1.3 The power factor L3 1.4 Practical values of power factor L4 Why to improve the power factor? L5 2.1 Reduction in the cost of electricity L5 2.2 Technical/economic optimization L5 How to improve the power factor? L7 3.1 Theoretical principles L7 3.2 By using what...

Original scientific paper Reactive power compensation methods are one of the most effective methods to improve the efficiency of energy systems. Therefore, the designs and implementations of these systems are important. The aim of this study is to design and implement the most appropriate reactive power compensation systems in electrical power systems. Reactive power compensation can be realize...