Showing papers by "Neville R. Watson published in 1995"

A new hybrid algorithm for analysis of HVDC and FACTS systems

Abstract: Hybrid stability programs use a transient stability analysis for AC power systems, in conjunction with detailed state variable or EMTP type modelling for fast dynamic devices. This paper presents a new hybrid algorithm that uses optimised techniques based on previously proposed methods. The hybrid provides a useful analysis tool to examine systems incorporating fast dynamic nonlinear components such as HVDC links and FACTS devices.

Steady state model of the AC/DC convertor in the harmonic domain

Abstract: A set of equations are developed that describe the six-pulse convertor in the steady-state harmonic domain. The method used is to directly convolve in the harmonic domain the DC voltage in each conduction period, with an appropriate sampling function. This avoids the need to use transfer functions, FFTs, or complicated Fourier transforms. The technique is fast and simple, and is able to model effects that have, until now, been largely ignored (such as the DC ripple effect on commutation duration). Moreover, the equations are suitable for inclusion in a Newton-type solution method, as the partial derivatives are easily obtained.

Harmonic State Estimation of Power Systems

Abstract: This paper presents a general overview of harmonic state estimation of power systems, including the major issues such as harmonic state estimator, observability analysis and optimal measurement placement. Based on partial synchronized measurements at selected buses and lines, complete harmonic information throughout a power system is estimated. Harmonic state estimation provides an efficient tool to identify and correct harmonic distortion for a whole system. The results of the research currently undertaken at the University of Canterbury are expected to be applied to the NZ and Spain power systems.

Harmonic Performance of Standard and Compact Fluorescent Lamps

Abstract: Power Quality is becoming an important issue due to the increasing number of devices being connected that draw a non-sinusoidal current waveform. Many loads connected to a power system rely on a stable sinusoidal supply voltage and if power quality is allowed to deteriorate sufficiently, there can be a tremendous cost associated with the malfunction of and even damage to equipment connected to the power system to say nothing of the cost of designing and installing remedial measures. Prevention is more cost effective than curing the problem after it appears, therefore there is a need for detailed harmonic penetration studies. However in order to do these studies the harmonic performance of the device must be determined. This paper presents the laboratory test results from testing the harmonic performance of a wide range of standard and compact fluorescent lamps. A wide range of results were found with a variation in total harmonic distortion (current) of 5.11 % to 146.69 % for compact fluorescent lamps and 5.53 % to 154.35 % for standard fluorescent lamps.

A high-pulse constant frequency inverter for DC and variable frequency generation sources

Abstract: There are many possible sources of DC and variable frequency AC power, yet standard commercial appliances require constant frequency AC power. This paper present an alternative inverter principle, which simplifies control hardware and reduces switching losses compared to PWM techniques, yet provides acceptable voltage and current waveforms. This is achieved by the use of reinjection techniques, which are applied to a forced commutated inverter. >