There have been reports of difficulties encountered in the operation of high-voltage ac-dc
conversion control schemes, particularly with reference to the so-called harmonic-instability …

A controlled mercury-arc or thyristor convertor with a conventional firing-pulse control system
can both generate and magnify ac harmonics additional to the fifth, seventh etc. of classical …

The adoption of voltage-controlled oscillator based firing systems has almost completely
eliminated the harmonic instabilities experienced in early HVDC systems. However, the …

The current control system of an HVDC converter has rather complicated dynamic
properties, and it is not possible to determine these by simple manual calculations. Instead …

In the practical design of hvdc convertor installations, a thorough investigation should be
made of all the possible component-overstressing situations that may arise for a variety of …

A method of analysis is presented and applied to a model system which is well established
and extensively used in studies of HVDC converters connected to weak AC systems. The …

The authors present stability conditions for constant switching frequency power converters
with current-mode control. The conditions take fully into account the interaction of the current …

A stability study of a dc power system is performed by applying Nyquist stability criterion to a
mathematical model that describes the behavior of the system during small disturbances …

A method is described which can be used to calculate the harmonics in convertor systems
both with fmite ac and dc impedances. The method is used to investigate a type of instability …

This thesis describes a linear and direct method of analysing the interaction of waveform
distortion around an HVdc convertor. Existing analysis techniques are reviewed, and their …