The emerging 400 V DC microgrid

  The smart grid has resulted in a number of new approaches to electricity distribution and reticulation, one of which is the microgrid. The extension of this concept to a microgrid based on DC, in the voltage range designated as low voltage for AC, offers an number of advantages over the use of AC and […]

Reducing SA’s electrical distribution transformer losses

  Forty-eight years after the birth of the first edition of the South African Bureau of Standards (SABS 780: 1966), little has been done in South Africa to reduce the distribution transformer losses as compared to first-world and BRICS countries, with the current edition have been released in 2009. Achieving increased energy efficiency through technological […]

Hierarchical control in a 5-terminal VSC-HVDC project

  The world’s first 5-terminal ±200 kV VSC-HVDC project was put into service on 4 July 2014. This project connects China’s mainland to five isolated islands. The project presented some significant technical challenges, especially with regards to the control and protection of the five terminals. A hierarchical control system was implemented to successfully overcome these […]

Enabling efficient network management in substations

  Creating a network management interface of devices and systems using different protocols can create risks and management issues which can compromise effectiveness and security for substation automation networks. An efficient and visually represented PRP/HSR network using power SCADA with specially designed management middleware can effectively avoid these problems. Traditional substation automation system (SAS) structure […]

Correcting capacitive power factor problems

  Eskisehir’s efficient new light rail train system, which runs on non-polluting electricity, has greatly benefited the general populace; but the system’s poor power factor has created a challenge for the power utility, as well as for the train’s system operators. This paper presents the solution employed to improve the power factor problem. Eskisehir, a city in […]

Protecting insulators from lightning damage

  Insulating joints (IJ) are used to electrically isolate pipeline systems or to isolate high-voltage-interference on pipelines into sections. Cathodically protected systems are electrically isolated until the dielectric strength of the insulating joint is breached. Surges caused by a lightning strike, into exposed parts of a pipeline system, may lead to the dielectric strength of […]

Reducing blackouts through power stability control

  China has one of the most complex interconnected HVAC and HVDC power grids in the world. All of the regional grids of China have implemented NR Electric’s Power Stability Control System (PSCS), which has dramatically improved the stability of the grids. The performance has been demonstrated, most visibly, in the reduction of blackouts, but […]

Assessing the effect of PV generation on distribution system voltages

  Utility distribution systems have seen a huge increase in distributed energy resources (DER) in recent years not only due to renewable portfolio standard requirements but also government financial support. Furthermore, it is becoming much more common for DER generation levels to significantly exceed the local load on the feeder to which it will be […]

South Africa: Electricity pricing paralysing the poor

  The electricity sector in South Africa has been in a state of disruption over the last few years. The country’s power utility company, Eskom, has been under scrutiny for several reasons. Most of these reasons relate to the rolling blackouts, load-shedding episodes of 2007/8 and high levels of inefficiency. Constant tariff increases under the […]

Losses and costs associated with HVDC and UHVDC transmission lines

  Reduction in electrical energy consumption requires power utilities to employ most efficient ways of electrical energy delivery from generation to distribution infrastructures. For bulk power transfer over long distances improved transmission efficiency is a primary target to ensure less electrical energy losses and costs. The application of conventional HVDC schemes at 500 kV DC […]