Power Quality Matters involve detecting phase imbalances and ensuring that all phasors have equal magnitudes and are symmetrically phase-shifted by 120 degrees relative to each other.
Transmission lines with high and extra-high voltage that are untransposed, meaning the conductors are not positioned at the corners of an equilateral triangle and lack an overhead grounding wire (OGW), significantly contribute to the generation of negative-sequence voltages and, to a lesser extent, zero-sequence voltages. As the electrical load increases, the incidence of negative-sequence voltages […]
Untransposed Transmission Lines Read More »
In a balanced three-phase network, the magnitudes of the voltages and currents in all three phases are the same and these voltages and currents phase are shifted symmetrically by 120 degrees to each other. If the magnitudes are not the same and phase-shifts are different from the 120 degrees, the network is unbalanced. Eskom strive
Phase Imbalance in Distribution Networks Read More »
When switchgear is poorly maintained and operated continuously, it is only a matter of time before something significant occurs. However, if these extreme events go unnoticed, the consequences can be long-lasting. During load-shedding, circuit-breakers should be opened when load-shedding starts and closed when load-shedding ends. Unfortunately, the contacts of these circuit-breakers are often concealed. As
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