On September 24, 2023, I posed an article in which I explained how poorly maintained switchgear could lead to long-lasting power quality issues. In that article, which was based on an actual incident in Benoni, Gauteng, South Africa, I mentioned that the voltages of two of the three phases increased by more than 51% while […]
What Is the Attitude Towards Power Quality Read More »
In the latest newsletter which would be published on November 14, 2023, I am making another attempt, this time, to catch the attention of accountants and financial officers explaining to them how unbalanced voltages, phase-shift variations, and harmonics disturbances would result in enormous economic losses. But first, I must go back to a previous blog
Cost of Complacency Read More »
In the mid-1980s, I embarked on a mission to resolve persistent “power failure” complaints from the National Accelerator Centre (NAC) in Faure, Western Cape, now known as iThemba LABS—the largest accelerator facility in the Southern Hemisphere. Invited for private tours, I delved into their operations, even entering the high-stakes environment of the operating room. Witnessing
Consequence of Weaknesses in Power Quality Read More »
Throughout my time in the power transmission and distribution industry I have probably had experiences that many others may never have. In a previous post, I talked about the current and voltage unbalances and how a large factory in the Western Cape in South Africa was severely affected by negative phase sequencing. In this post
Power Network Disturbances Read More »
To mitigate the effects of Load-Shedding, many homeowners have decided to install PV Solar Energy systems. And, as I said before, they are more worried about how much it would cost than the quality of the products. If they can pay the lowest possible price for the entire installation, they are happy and do not
Power Quality Issues Caused by Distributed Generation Read More »
With our comprehensive Negative Phase Sequence Consulting Services, we deliver expert analysis and innovative solutions to effectively manage negative sequence currents in three-phase electrical systems. Our services are designed to identify and address issues caused by unbalanced loads, faults, and system abnormalities, ensuring system stability, reducing equipment wear, and significantly enhancing overall power quality. We
Learn More About Rotating Voltage and Current Vectors Read More »
Practical imperfections which can result in unbalances are: A three-phase equipment such as induction motor with unbalance in its windings. If the reactance of three phases is not same, it will result in varying current flowing in three phases and give out system unbalance. With continuous operation, motor’s physical environment cause degradation of rotor and
Causes of Unbalanced Voltages and Currents Read More »
In recent times, I have attended several seminars and that makes me wonder whether the entire process of Solar Energy Systems installation has anything to do with Electrical Engineering, or is it perhaps closer to something like tree cutting where there are so many claiming to be “experts” in that field. Almost daily, we receive
Is Solar Energy a Subset of Electrical Engineering Read More »
Extremely long—hundreds of kilometers—untransposed high and extra-high voltage transmission lines with a flat, horizontal conductor configuration significantly contribute to negative-sequence voltages and, to a lesser extent, zero-sequence voltages. The incidence of negative-sequence voltages rises with increasing electrical load. In the late 1970s and early 1980s, Eskom operated two 400kV transmission lines to the Western Cape:
Learn the Hidden Impact of 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 »
