This paper reports the results of an experimental investigation into the characteristics and effects of a PWM inverter on the power supply and overall performance of a capacity controlled refrigeration system employing a positive displacement compressor. The results indicate that the efficiency of variable speed refrigeration systems at part load is severely affected by the poor performance of ...

In this paper, a new approach is proposed for voltage and current harmonics compensation in grid-connected microgrids (MGs). If sensitive loads are connected to the point of common coupling (PCC), compensation is carried out in order to reduce PCC voltage harmonics. In absence of sensitive loads at PCC, current harmonics compensation scenario is selected in order to avoid excessive injection of...

Abstract—in this paper a concept of generalized theory of instantaneous imaginary power is proposed for a three-phase four-wire system. Unlike instantaneous reactive power theory in which a complex mathematical transformation is used for controlling action of shunt active power filters. The proposed control strategy is simple and further to reduced its complexity the line current vector is deco...

This paper reports the performance of a speed sensorless stand-alone Variable Speed Constant Frequency (VSCF) Doubly Fed Induction Generator (DFIG) capable of supplying all types of loads. The proposed method maintains the Total Harmonic Distortion (THD) of the machine current and the load voltage within acceptable limits. In contrast to previously proposed methods, in this paper, the stator si...

Molecular motors are responsible for numerous cellular processes from cargo transport to heart contraction. Their interactions with other cellular components are often transient and exhibit kinetics that depend on load. Here, we measure such interactions using 'harmonic force spectroscopy'. In this method, harmonic oscillation of the sample stage of a laser trap immediately, automatically and r...

This study used both time and frequency domain analyses to investigate walking patterns with ankle load in children and adults. Twenty-two children aged 7-10 years and 20 young adults participated in this study. Three levels of ankle load were manipulated: no load, low load (2% of body mass on each side), and high load (4% of body mass on each side). An instrumented treadmill was used to regist...

We proposed voltage-sourced converter (VSC) with Pulse-width modulation (PWM) provides a faster control that is required for flicker mitigation purpose. The voltage regulation in the distribution feeder is improved by installing a shunt compensator. The proposed DSTATCOM is modeled and its performance is simulated and verified for power factor correction and voltage regulation along with neutra...

We describe a new design technique for efficient harmonic resonant rail drivers. The proposed circuit implementation is coupled to a standard pulse source and uses only discrete passive components and no external dc power supply. It can thus be externally tuned to minimize the consumed power in the target IC. A new design technique based on current-fed voltage pulse-forming network theory is pr...

Modern power system networks use active power filters for compensation of harmonic currents generated by non linear loads. In this paper a new method for generating reference currents for harmonic and reactive power compensation is proposed. The proposed method has the advantage that it generates the reference currents irrespective of the supply voltage and load conditions. So the source has to...

Three-Phase four-wire distribution systems are facing severe power quality problems such as poor voltage regulation, high reactive power and harmonics current burden, load unbalancing, excessive neutral current, etc.This creates excessive neutral current both of fundamental and harmonic frequency and the neutral conductor gets overloaded. By integrating phase shifting into an extremely low zero...