Power System Overvoltages and Insulation Coordination – Part 2
This is Part 2 of this series, the first part could be found here. Insulation coordination is the “selection of the dielectric strength of equipment in relation to the voltages …
Power System Overvoltages and Insulation Coordination – Part 1
Note: This is the first part of power system voltages and insulation coordination. Insulation coordination is dealt with for three phase AC systems with nominal voltages Un > 1kV in …
The Effect of Earthing Methods
Earthing the System Neutral Most earthed systems employ some method of earthing the system neutral at one or more points. Effectively Earthed System A system is effectively earthed when the …
Normative and Informative Annexes Compliance
The terms ‘normative’ and ‘informative’ are commonly used in IEC and other derivative standards to define applications of annexes. A normative annex is an integral part of a Standard which …
Sub-synchronous torsional interaction (SSTI)
Definition Sub-synchronous torsional interaction (SSTI) is a phenomenon in power systems where mechanical torsional oscillations of a turbine-generator shaft interact with the electrical sub-synchronous frequency components of the power system. …
Voltage and Frequency Limits of Electric Motors – IEC 60034-1
Electric motors rated for use on a fixed frequency power supply, combinations of voltage variation and frequency variation are classified as being either zone A or zone B, in accordance …