Transmission Lines and Safety Considerations

 

A California-based electrical engineer, Dianoush Emami has significant experience designing power plants. Dianoush Emami has set up high-voltage transmission and electrical distribution systems that provide a consistent, safe energy source.

Transmission lines carry energy in large quantities from generating stations to substations, which can be distributed to individual businesses and households. The design and capacity of such lines vary widely, ranging from 44,000 volts to more than 750,000 volts.

Because of the high load capacity and extremely high voltage, transmission lines do not have an insulating sheath, as with the smaller loads involved with electrical lines and poles from substations. Instead, the air around the lines acts as an insulator, making it critical that nothing comes close to them, such as a tree branch, that might cause serious fire and outage. Because of the high voltages, a tree does not even need to touch the line for an electric arc to occur.

For this reason, all transmission lines are set up with right-of-ways that prevent vegetation from being planted in the vicinity. In addition, this cleared area enables personnel to access lines for inspections, repair, and maintenance.

Basic Types of Underground Transmission Lines

 Based in Southern California, Dianoush Emami oversees complex electrical engineering projects that enable power plants to function at capacity reliably. Over the years, Dianoush Emami has managed electrical engineering projects involving the placement of high-voltage overhead and underground lines.

Underground transmission lines must overcome various technical challenges that make the cost per foot between four and seven times that of overhead lines. One major obstacle involves providing enough insulation that cables can be placed only inches from grounded material. In addition, the heat generated when operating electrical cables needs to be rapidly dissipated within a confined space. With overhead lines, engineers have the luxury of lines surrounded by insulating air and safely distant from each other.

Two basic underground transmission line configurations resolve these concerns. High-pressure fluid-or-gas-filled cables involve three high-voltage conductors encased within a steel pipe. Pressurized nitrogen or synthetic oil acts as an insulator, without itself conducting electricity, and prevents unwanted electrical discharges. The fluid, generally static and operating by conduction, also transfers heat from the conductors. Issues that can potentially arise include leaking oil that impacts groundwater and soil.

The other major option is a solid cable made of dielectric material, such as the XLPE cable, which has an aluminum or copper conductor and a semi-conducting shield at the core. Surrounding this core is cross-linked polyethylene insulation, with a metallic sheath and plastic jacket covering the entire cable. This effectively provides insulation and heat dissipation without fluid leakage risks.

SF6 Circuit Breakers for High Voltage

 After receiving his bachelor's degree in electrical engineering from the University of Southern California, Dianoush Emami has accumulated several professional certifications in the electrical engineering sector. With over three decades of experience in his field, Dianoush Emami’s particular areas of expertise include quality control, safety, and high-voltage transmission work.

High-voltage circuit breakers protect electrical circuits from hazardous spikes. One common type of high-voltage circuit breaker is the SF6 circuit breaker. SF6 circuit breakers use a gas called sulfur hexafluoride as their dielectric material. The circuit breaker cuts power when there is an overload or a short circuit, protecting electrical systems and assets.

The three major types of SF6 circuit breakers are the single interrupter SF6 CB (designed for 220 kV systems), the two interrupters SF6 CB (designed for 400 kV systems), and the three interrupters SF6 CB (designed for 715 kV systems).

Circuit breakers are a more efficient alternative to fuses. Contrary to fuses, designed to protect against dangerous current only once, circuit breakers can be reused. One disadvantage of SF6 circuit breakers is that the constituent gas (sulfur hexafluoride) is a greenhouse gas and can contribute to global warming when it escapes into the atmosphere through the leakage.

Argonne National Laboratory's Vetted Biofuel Efficiency Study

 A former electrical engineer at Bechtel Power Corporation, Dianoush Emami has worked throughout the state of California for more than 35 years. During this period, he has established himself as a professional in high-voltage transmission and substation design. Dianoush Emami has also worked on projects in the nuclear power and biofuel sectors.

In November 2022, the U.S. Department of Energy's Argonne National Laboratory collaborated with the Pacific Northwest National Laboratory, the National Renewable Energy Laboratory, and the Idaho National Laboratory to conduct research that can help match promising biofuels with compatible engine types. The consortium builds on the rationale that advanced engine designs can improve biofuel efficiency while simultaneously reducing carbon emissions.

The studies, published in ACS Sustainable Chemistry & Engineering, outline the prospects of biofuel as a climate-friendly alternative energy source. Biofuels are produced from animal fats and oil extracted from plants, which are renewable, in contrast to petroleum. The researchers found that pairing compatible biofuels with advanced, optimally designed engines can reduce greenhouse gas emissions by 60 percent, mitigating climate hazards. They also found that optimized engines can go farther on equal amounts of fuel compared to conventional engines.

IEDs and Substation Automation

 An experienced electrical safety professional, Dianoush Emami graduated with a BS in electrical engineering from the University of Southern California. Drawing on a career spanning three decades, Dianoush has also designed and implemented high-voltage systems for use in power generation and electrical substation facilities.

Intelligent Electronic Devices (IEDs) are built using microprocessor technology. In substations, IEDs serve as an integral component of the substation automation system. They essentially collect data on the state of different substation devices, process and interpret the data, and trigger autonomous control commands in a fraction of a second if an abnormal situation is identified. The control command can sometimes remedy the fault completely.

IEDs can also transfer information via multiple communication modes. Local operators and remote personnel can access this information for troubleshooting. In most substations, a special system called the Supervisory Control and Data Acquisition (SCADA) system centralizes communication from various IEDs, streamlining substation supervision.

Understanding High Voltage Transmissions and their Safety Precautions

 Dianoush Emami is an accomplished California-based electrical engineer, who draws upon more than three decades of experience. An alumnus of University of Southern California, Dianoush Emami has worked extensively as a high voltage engineer in electrical distribution and transmission.

High voltage electricity is utilized for multiple uses, including power generation to managing industrial plants. Transmission and distribution lines operate on significantly higher voltages compared to homes and businesses, as they carry huge amounts of power. Due to the massive amount of electrical energy involved, high voltage electrical sites should be installed far away from people and properties. To ensure any potential safety hazards have been addressed, high voltage electricity is often regulated and managed under close supervision. This allows for power levels to be maintained within industry-approved levels.

For high-voltage installation sites to remain safe, adequate insulation to maintain voltage levels and physical isolation measures should be implemented to prevent accidents. Installations are required to comply with the National Electrical Code and other applicable local codes. For insulation, regular testing should be done, as insulation degenerates when exposed to very high temperatures and chemical agents. A megohmmeter is an insulation tester device used to measure high resistance values, by transmitting a high voltage signal to an object being tested, in order to determine an insulation’s performance.

A Brief Look at Substation Automation Systems

 An electrical engineering alumnus of the University of Southern California, Dianoush Emami is an accomplished electrical engineer who worked at Bechtel Power Corporation for six years. Dianoush Emami has also implemented high-voltage systems in power generation facilities and electrical substations.

A substation automation system is a series of hardware and software components that help monitor and control electrical systems at electrical substations. With a substation automation system, electrical engineers no longer need to perform many tedious and repetitive tasks on-site at substations. These tasks are handled by complex algorithms embedded in substation automation systems' components. Some of these tasks are traditionally error-prone. Algorithms eradicate human errors.

Substation automation systems minimize electric system faults and downtime, expedite critical troubleshooting, optimize productivity, and boost revenue for electrical companies. These systems also streamline the analysis of hazards by recording and transferring data to locations where the data can be analyzed to determine the causes and patterns of component failures. With this information, engineers can take the necessary actions to prevent component faults and failures from happening again.

Many components of modern substation automation systems are microprocessor-based intelligent electronic devices (IEDs). Supervisory control and data acquisition system (SCADA) helps monitor multiple IEDs.