This paper gives an overview of the ongoing activities in CIGRE WG36-07: "Power quality indices and objectives". It introduces the considerations supporting the need for power quality indices and objectives in the present context of deregulation of the electricity industry. Experts generally agree on the need for standardized quality indices allowing to monitor and to report power quality in a common format. However, concerning quality objectives the need is more likely for different levels of quality that can match customers expectations and the price they are willing to pay for electricity. Some practical limitations to voltage quality monitoring are also discussed. The status of the work within the working group is described for harmonics, flicker, unbalance and voltage dips.

The HVDC (High Voltage Direct Current) transmission system, although in use since about half a century, is gaining new popularity in recent years, as it can allow to transmit very large amounts of power over long distance at reasonable costs. Many plants are being commissioned and many others are in the design phase, both for mainland and submarine links. Ground/sea electrodes are normally used in such applications, either operated on a full time basis, or during partial failures of one pole of bipolar plants. Due to the adverse effects that stray currents dispersed by such electrodes may have in terms of corrosion to nearby structures, and to the growing concern for environmental issues, the design of sea electrode has to be defined with increasing attention. This paper deals with the technologies and with the design criteria that can be adopted to develop satisfactory sea electrodes.

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