Non-sinusoidal System Research Articles

Analysis of harmonic mitigation methods for building wiring systems

There is a growing number of available harmonic mitigation methods. Selection of the best suited method for a particular case can be a complicated decision making process. The difficulty normally arises from not knowing how a particular technology and design will perform in a specific nonsinusoidal system. This paper looks at seven harmonic mitigation methods and compares their compensation characteristics as applied to building wiring systems. Both passive and active mitigation methods are considered for harmonics generated by single-phase equipment. The performance is studied through computer simulation with detailed source and associated rectifier load interfaces in the model.

Power components in a system with sinusoidal and nonsinusoidal voltages and/or currents

Currently accepted definitions of power components are reviewed, and their disadvantages are analysed. New definitions of active, reactive, distortion, and apparent power are discussed. It is attempted to find a clear physical interpretation, and to formulate this for each power component in systems with sinusoidal and/or nonsinusoidal voltage and current. Formulas for the straightforward calculation of each power component are obtained. It is shown that (a) distortion power, as defined here consists of both active and reactive terms (b) apparent power in a nonsinusoidal system must be represented as a many-dimensional vector, and not as a vector of three dimensions as is generally accepted today. Examples are given to illustrate the application of the developed theory.

A Direct Method for Identifying the Optimal Power Factor Correction in Nonsinusoidal Systems

This paper presents a new method employing the Golden Section search algorithm to determining the capacitor value for optimal power factor correction in a nonsinusoidal system. The major attribute of the method is that it, unlike conventional approaches, guarantees convergence to the optimal solution. This accomplishment is a direct result from the improvement in (1) the algorithm in which provisions are made to identify and to avoid capacitor values which would create resonant conditions, and (2) the problem formulation in which the effect of the transmission line impedance on the load voltage is included while calculating the optimal capacitor value. Finally, the contribution of the newly developed method is demonstrated in examples taken from previous publications.

A Direct Method for Identifying the Optimal Power Factor Correction in Nonsinusoidal Systems

This paper presents a new method employing the Golden Section search algorithm to determining the capacitor value for optimal power factor correction in a nonsinusoidal system. The major attribute of the method is that it, unlike conventional approaches, guarantees convergence to the optimal solution. This accomplishment is a direct result from the improvement in (1) the algorithm in which provisions are made to identify and to avoid capacitor values which would create resonant conditions, and (2) the problem formulation in which the effect of the transmission line impedance on the load voltage is included while calculating the optimal capacitor value. Finally, the contribution of the newly developed method is demonstrated in examples taken from previous publications.

A new approach to the load compensation of a single-phase nonsinusoidal system

A microprocessor-based instrument to compute the value of capacitance and/or inductance which minimises the RMS value of line current when connected in parallel with the load, is described. The instrument can be used with systems having arbitrary voltage/current waveforms. The method is based on obtaining the least-squares solution of a set of equations which are formed by taking samples of derivatives of line voltage, integrals of line voltage and line current.

Steady-State Analysis of a Two-Branch Resistance-Inductance Parallel Circuit Controlled by a Forced-Commutation Bidirectional AC Switch

The currents and load voltage of a two-branch resistance-inductance (RL) parallel circuit controlled by a forced-commutation ac switch in the supply line are deduced. With two numerical examples, it has been shown that the effective power factor of the nonsinusoidal system can exceed that of the load to sinusoidal supply which represents a great improvement, but all are of lagging values.