A solution of a rectifier filter circuit with a capacitive input

In the last fifteen years a number of analyses of the full-wave rectifier circuit with a condenser-input filter have been made, and several of these analyses have presented characteristic curves which could be used in the design of the circuits. These analyses used rather severe assumptions in most cases, and the characteristics were applicable only over a small range of parameters. The present investigation was started with the idea of using more liberal assumptions and producing characteristics suitable for design work that could be used from open-circuited to short-circuited loads and with all values of filter inductances in practical use;In the solution of the circuit equations, the usual method of differential equations was tried and abandoned, and a new steady-state operational calculus developed for this type of problem was tried and was successful in solving the circuit equations. This solution was made for various values of the parameters and was extended to the cases where one or more of the parameters became zero or infinitely large;The boundary between the cut-off and the non-cut-off types of operation was obtained, and the solution of the non-cut-off case was made. The point of filter resonance was approached very closely, but difficulties with the solution prevented further investigation of the resonance condition;Characteristic curves and equations suitable for use in design and covering the range from open-circuited to short-circuited loads and from very large filter inductances to such small ones that filter resonance almost occurs, were constructed. A method of using these characteristics in the actual design of rectifier and filter circuits was also presented;Experimental results of the operation of an actual circuit were presented and found to agree very closely with the calculated results particularly when correction is made for the resistance of the tube and filter inductance. The correction can also be applied in the design work. Several possible future extensions to the present analysis and characteristics were also suggested

Analysis and control of dual-output LCLC resonant converters with significant leakage inductance

The analysis, design and control of fourth-order LCLC voltage-output series-parallel resonant converters for the provision of multiple regulated outputs, is described. Specifically, state-variable concepts are developed to establish operating mode boundaries with which to describe the internal behavior and the impact of output leakage inductance. The resulting models are compared with those obtained from SPICE simulations and measurements from a prototype power supply under closed loop control to verify the analysis, modeling, and control predictions

Analysis and control of dual-output LCLC resonant converters, and the impact of leakage inductance

The analysis, design and control of 4th-order LCLC voltage-output series-parallel resonant converters (SPRCs) for the provision of multiple regulated outputs, is described. Specifically, state-variable concepts are developed to establish operating mode boundaries with which to describe the internal behaviour of dual-output resonant converters, and the impact of output leakage inductance. The resulting models are compared with those obtained from SPICE simulations and measurements from a prototype power supply under closed loop control to verify the analysis, modeling and control predictions

Hybrid HVDC for supply of power to offshore oil platforms

A HVDC hybrid system, comprising a line commutated thyristor HVDC converter and a STATCOM, is proposed in this paper for supplying power to offshore oil platforms that do not have their own generation. The proposed system combines the robust performance, low capital cost and low power loss of a line commutated HVDC converter, with the fast dynamic performance of an equivalent VSC Transmission system. The paper describes the principles and control strategies of the proposed system. PSCAD/EMTDC simulations are presented to demonstrate the robust performance of the system using case studies of various operating conditions such as black-start, load perturbations, AC fault conditions and disturbance caused by the starting of large local induction machines

Modelling and regulation of dual-output LCLC resonant converters

The analysis, design and control of 4th-order LCLC voltage-output series-parallel resonant converters (SPRCs) for the provision of multiple regulated outputs, is described. Specifically, state-variable concepts are employed and new analysis techniques are developed to establish operating mode boundaries with which to describe the internal behaviour of a dual-output resonant converter topology. The designer is guided through the most important criteria for realising a satisfactory converter, and the impact of parameter choices on performance is explored. Predictions from the resulting models are compared with those obtained from SPICE simulations and measurements from a prototype power supply under closed loop control

Analysis of CLL voltage-output resonant converters using describing functions

A new ac equivalent circuit for the CLL voltage output resonant converter is presented, that offers improved accuracy compared with traditional FMA-based techniques. By employing describing function techniques, the nonlinear interaction of the parallel inductor, rectifier and load is replaced by a complex impedance, thereby facilitating the use of ac equivalent circuit analysis methodologies. Moreover, both continuous and discontinuous rectifier-current operating conditions are addressed. A generic normalized analysis of the converter is also presented. To further aid the designer, error maps are used to demonstrate the boundaries for providing accurate behavioral predictions. A comparison of theoretical results with those from simulation studies and experimental measurements from a prototype converter, are also included as a means of clarifying the benefits of the proposed techniques

The design of an electric fence monitoring system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Production Technology at Massey University

This thesis presents the design of an Electric Fence Monitoring System (EFMS) which detects and announciates fence malfunctions indicating operational ineffectiveness. The EFMS consists of a master unit and up to sixteen slave units. Each slave unit monitors a single remote point on the fence. Slave units gain their power from the electric fence pulse itself. They use a unique transmission algorithm to transmit the peak electric fence voltage, to the master unit. The electric fence wire is used to convey this transmission. The master unit uses a non-linear switched capacitor filter with variable gain control, to detect the slave unit transmissions. This unit displays the peak voltage at each monitored point and allows the setting of alarm trigger points. This thesis includes modelling of the electric fence energiser and typical electric fence line, and the detailed design of the two units that makeup the EFMS

Load insensitive electrical device

A class of power converters is described for supplying direct current at one voltage from a source at another voltage. It includes a simple passive circuit arrangement of solid-state switches, inductors, and capacitors by which the output voltage of the converter tends to remain constant in spite of changes in load. The switches are sensitive to the current flowing in the circuit and are employed to permit the charging of capacitance devices in accordance with the load requirements. Because solid-state switches (such as SCR's) may be used with relatively high voltage and because of the inherent efficiency of the invention that permits relatively high switching frequencies, power supplies built in accordance with the invention, together with their associated cabling, can be substantially lighter in weight for a given output power level and efficiency of operation than systems of the prior art

Cost-effective applications of power factor correction for nonlinear loads

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2005 IEEEThe objective of this paper is to propose a new approach for designing passive LC compensators by using the penalty function method as an optimization tool. The performance of the cost-effective passive LC compensator for a constant load depends on the appropriate inductor and capacitor selection. Several design methods are reviewed and a novel design methodology is proposed in this paper. By using the proposed method, the designer can quickly find appropriate parameter values to meet the desired circuit performance. Simulated results show that an appropriate combination of the inductor and capacitor selected by the proposed method can meet the desired power-quality requirement. Different cases of design examples are shown in this paper to verify the performance of the proposed design methodology

Investigation of the Coupling Paths of a Galvanically Isolated AC/AC Converter

A galvanically isolated three-phase AC/AC converter with a high-frequency AC-link has been analyzed from an EMC point of view. This is a special configuration because of a large number of switches, a high frequency transformer, and a fourwire output. The essential coupling paths are identified.\ud Corresponding suppression remedies are given. The results, before and after measures, have been presented to demonstrate the improvement in EMC.\ud Keywords: AC/AC converter; electromagnetic interference; galvanically isolated\u