With the progress of power electronic devices in electric railway, harmonics in power systems become increasingly of concern. This paper presents a case study on harmonics in a traction power supply system. The study was based on measurements realized in an electrical drive station using a data acquisition system and a computer. It was analyzed the main power quality indicators: the power facto...

A fast two-vector Phase-locked loops (PLL) control has been proposed to the phase and frequency of grid voltage using 48-pulse switching. The novel controller senses shift as a deviation by load locked positive sequence. was designed track angle kept within satisfying rang at all time. PI- obtain desired performance PLL. PLL voltage. test results shows that new design can response sequence betw...

the cúk converter, which has voltage buck and boost ability, offers high flexibility as an interface device for solar panels. in addition, current ripple can be more reduced because of two input and output inductors at both sides. this paper presents a new application of current-variable inductors in a cúk converter that reduces the size and capacity of storage elements. because of two inductor...

in this paper, a new topology for boost z-source inverterbased on switched-inductor cell is proposed. the operating modes of the proposed inverter are analyzed and also a suitable control method to generate the trigger signals of the inverter is presented. having a common earth between the input source and inverter and capability to generate a higher voltage gain by using lower amounts of the d...

This paper addresses the timely issue of modeling and analysis of custom power controllers, a new generation of power electronics-based equipment aimed at enhancing the reliability and quality of power flows in lowvoltage distribution networks .The modeling approach is graphical in nature, as opposed to mathematical models embedded in code using a high-level computer language. The well-develope...

In this paper, a new circuit is proposed for step-up Z-source inverter based on QZSI (quasi-Z-source inverter). The proposed topology inherits all advantages of the conventional topology. The proposed topology in comparison with conventional topology reduces the ST (Shoot-through) duty cycle by over 25% at the same voltage boost factor. Theoretical analysis of the proposed qZSI in the ST and no...

Abstract Distributed bus protection is one of the main tasks smart substation construction to improve secondary system because it economical, simple, easy layout, and realize double. This paper mainly considers that distributed current differential limited by high precision synchronization bandwidth a based on directional impedance element comparison principle proposed. The constructed reverse ...