In this paper a hybrid active DC line conditioner for fluctuations and ripples reduction in voltage and current of DC power systems is proposed. Malfunctions in operation of equipments and systems which are supplied by low quality distribution power systems are one of the main effects of DC voltage ripple. In the proposed configuration a hybrid system including series and shunt active line ...

Increasing interest is being shown in the use of microprocessor for protection, switching and data acquisition required in modern high voltage substations. One of the most difficult functions to fulfill is that of transmission line distance protection employing samples of the voltage and current waveform taken from high voltage transducer equipment at the usual relaying point. This paper examin...

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...

crop density measurement is one of the most important factors in precision farming and effect onthe performance of harvesting machines such as combine and mower. so, the purposes of this studyare to design, build and calibrate of an inexpensive and non-contact instrument that can estimatecrop density for crops such as wheat, barley and alfalfa stems. the sensing unit is consisted of lasertransm...

In a de-regulated open access environment, reactive power is one of the ancillary services which must be provided by an Independent System Operator (ISO). In this paper, a new algorithm is proposed in which reactive power resources are initially so tuned that optimum security in terms of voltage profile and voltage stability are achieved while at the same time, the system losses are minimized. ...

A major problem in an isolated DC/DC converters operating at high switching frequencies is the attendant switching losses in the semiconductor devices. This can be reduced by introducing either zero-voltage switching (ZVS) or zero-current switching (ZCS) of the semiconductor switches. This paper deals with the simulation, design, fabrication and experimental evaluation of a novel soft-switching...

this paper presents a novel control method to improve the efficiency of low-voltage dc-dc converters at light loads. pulse width modulation (pwm) converters have poor efficiencies at light loads, while pulse frequency modulation (pfm) control is more efficient for the same cases. switching losses constitute a major portion of the total power loss at light loads. to decrease the switching losses...

In this paper, dynamic performance of a transformerless cascaded PWM static synchronous shunt compensator (STATCOM) based on a novel control scheme is investigated for bus voltage regulation in a 6.6kV distribution system. The transformerless STATCOM consists of a thirteen-level cascaded H-bridge inverter, in which each voltage source H-bridge inverter should be equipped with a floating and iso...

In this paper, Intelligent water drop algorithm (IWD) is used to analyze single overhead line connected to grid-grounded arrester. In this approach, at first Norton’s equivalent circuit of the overhead line over lossy soil is computed by method of moments (MoM) and then for the problem under consideration, a nonlinear equivalent circuit in the frequency domain is proposed. Finally applying inte...

In this article, the electrode erosion and the gap growth of spark plugs were measured on of a CNG fueled engine after durability tests. Then, the required ignition voltage and the spark quality were investigated by a spark plug test rig. Considering results of measurements, the gap growth increased as the running time increased. Thus, the gap growth of spark plugs with 200 and 280 hours runnin...