Wieslaw E. Bury

New type T-Source inverter

This paper presents different topologies of voltage inverters with alternative input LC networks. The basic topology is known in the literature as a Z-source inverter (ZSI). Alternative passive networks were named by the authors as T-sources. T-source inverter has fewer reactive components in comparison to conventional Z-source inverter. The most significant advantage of the T-source inverter (TSI) is its use of a common voltage source of the passive arrangement. Experimental results for the TSI are in agreement with theoretical and simulated prediction.

New Alternative Passive Networks to Improve the Range Output Voltage Regulation of the PWM Inverters

This paper presents different topologies of buck-boost converters with passive input networks that have alternative topologies; this is known in the literature as a Z-source inverter. Alternative passive networks were named by the authors as T-inverters; these improve output voltage regulation of the PWM inverters. T-inverter has fewer reactive components in comparison to conventional Z-source inverter. The most significant advantage of the T-inverter is its use of a common voltage source of the passive arrangement. This solves many problems involving electromagnetic compatibility which are present in the Z-source inverter. Experimental results for the T-inverter are in agreement with theoretical and simulated predictions.

High efficiency adaptive boost converter for LED drivers

This paper presents the design and simulation results of an 89% power efficient CMOS adaptive controlled boost (step-up) LED driver implemented in 0.25 μm BCD (Bipolar CMOS DMOS) technology. A novel adaptive minimum frequency control provides up to 32 V from a single battery (3.6 V to 5.5 V) input supply to 10 series-connected LEDs at the output. The proposed control scheme provides an accurate load current (3–50 mA) while achieving 6%–12% higher power efficiency than conventional fixed on-time schemes. The novel control circuitry is able to switch between PWM (Pulse width modulation) and PFM (Pulse frequency modulation) automatically by calculating the feedbacks from the inductor and LEDs currents. This controller is functional from light to heavy loading situations which is critical in improvement of power efficiency and battery life-time for high-boost ratio applications in order as provide accurate LED current.

DSP H/spl infin/ controller for a variable output DC-DC converter: design and implementation

An H/spl infin/ controller for power conversion was designed and tested employing a DSP (digital signal processor) to implement the 2nd order transfer function. The DSP was programmed for and tested with a bi-directional flyback converter. The results of the DSP control conform to that of theory and analog control results.

Reference to output frequency compensation of bidirectional DC-DC converter

A bidirectional flyback converter with output voltage tracking capabilities was designed and tested. For the first time an H/spl infin/ approach was used for a controller design. A better performance of the H/spl infin/ controller over a traditional reference-to-output frequency-compensated one was shown. Theoretical results were validated by simulations and experiments.

A time sequence load-flow method for steady-state analysis in heavily meshed distribution network with DG

A time sequence load-flow method for steady-state analysis in large scale heavy meshed distribution system with Distributed Generations (DG) is proposed in this paper. Since DG is the intermittent type source, and distribution system has time delay based protection device, traditional single snapshot load-flow methods has limitations in the case with DG. Proposed time sequence load-flow method is based on iterative load-flow calculation and can estimate the timestamp of each time load-flow calculation result. The proposed load-flow calculation iteration starts when studied distribution system status changes, such as protection device operations, and stops when studied distribution system is in a steady-state. It also can used to determine a distribution systems final stage and when a system will be in its final steady-state. In simulations, a heavily meshed distribution network with DG and two different protection devices is modeled in the proposed method. Simulation results are compared with simulation in EMTP-RV. The results show that the proposed method can generate results very close to EMTP-RV while taking considerably less time.

Distributed Induction Generators: 3 - Phase Bolted Short - Circuit Fault Currents

This paper presents methods for estimation of the value of the 3-phase bolted short circuit current of induction distributed generators. It justifies new, quick, and fairly simple way for approximation of the value of peak currents during the first several cycles of the fault. During the study, numerical simulations of the fault have been performed and compared to the results from the estimation. The analytical and numerical results have been validated by a scaled-down experimental setup with a 2 kW induction generator.

Design and implementation of an H/sub /spl infin// controller for a bi-directional DC-DC converter

An H/sub /spl infin// controller for use in a bi-directional flyback converter was designed and tested. Earlier work has shown that the H/sub /spl infin// controller is superior to that of a traditional reference-to-output frequency-compensated controller. The design of the H/sub /spl infin// controller was verified in open and closed loop simulations and on-going experimentation.