Giving grid sensors a boost

Electrical physicists from Czech Technical University are offering recommendations for improving sensor accuracy as the electrical grid becomes more complex.

01/10/2018


Current sensors introduce errors when assessing current through iron conductors so it is important to correct the flaw in new sensors so grid operators can respond to threats to the system.

There is a difference in a conductor's magnetic permeability, the degree of material's magnetization response in a magnetic field, affects the precision of new sensors, said electrical physicists from Czech Technical University. Finding the issue is one thing, they also are offering recommendations for improving sensor accuracy.

With the addition of new renewable energy sources and smart homes demanding more information, the electrical grid is becoming more complex.

"If you have [a] grid at the edge of capacity, you have to be careful to monitor all the transients (power surges)," said Pavel Ripka, an author of a paper on the subject.

Surges are overloads or failures to the system, which can end up caused by something as simple as a broken power line, or more dramatic events like lightning strikes or geomagnetic storms.

"Every day you get a lot of these small events (surges) within a big power grid, and sometimes it is difficult to interpret them," Ripka said. "If it is something really serious, you should switch off parts of the grid to prevent catastrophic damage, but if it's a short transient which will finish fast there is no need to disconnect the grid. It's a risky business to distinguish between these events, because if you underestimate the danger then parts of the distribution installations can be damaged causing serious blackouts. But if you overestimate and disconnect, it is a problem because connecting these grids back together is quite complicated," he said.

To address the increasing complexity of the grid and power outage threats, there has been an increase in use of ground current sensors. New yokeless current sensors are popular because of their low cost and compact size. These sensors are good for assessing currents in nonmagnetic conductors such as copper and aluminum. However, ground conductors are usually iron due to its mechanical strength, and iron has a high magnetic permeability.

Using these new sensors to measure ground currents when iron is present is a bit like using a thermometer to assess if the heating needs to be switched on, not taking into account where exactly the thermometer is placed. Near a door or window, the thermometer's reading can be affected differently than elsewhere. In the same way, this study has shown not taking the magnetic permeability of a conductor into account distorts the accuracy of a reading with a yokeless sensor.

Ripka and his team matched experimental measurements with theoretical simulations to highlight the difference in yokeless sensor readings between nonmagnetic and magnetic conductors.

"We can show how to design (yokeless) current sensors so that they are not so susceptible to this type of error," Ripka said. "[This study is] just a small reminder to make [engineers] design sensors safely."

To further prove the point, Ripka's group is starting to take long-term readings at power stations, comparing results to commercial uncalibrated sensors. In the future, Ripka envisions cooperating with geophysicists to correlate ground currents and geomagnetic activity, to better understand how these currents are distributed within the earth and even predict future disruptions to the grid.

Gregory Hale is the editor and founder of Industrial Safety and Security Source (ISSSource.com), a news and information Website covering safety and security issues in the manufacturing automation sector. This content originally appeared on ISSSource.com. ISSSource is a CFE Media content partner. Edited by Chris Vavra, production editor, CFE Media, cvavra@cfemedia.com.

ONLINE extra

See related stories from ISSSource linked below.



The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers. Vote now (if qualified)!
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
DCS visibility, alarm management, motors and drives, robotic machining, Engineers' Choice winners
Factory automation controllers, Ethernet updates, System Integrator of the Year roundtable, Inside Process and VFDs
Robotic simulation and welding, Process building blocks, Discrete sensor advice, Virtualization advice
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. As we know, PLCs aren’t the only option for making decisions in a control loop, but they are likely why you’re here.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This article collection contains several articles on how advancements in vision system designs, computing power, algorithms, optics, and communications are making machine vision more cost effective than ever before.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Focus on power systems, process safety, electrical and power systems, edge computing in the oil & gas industry
Product of the Year winners, Pattern recognition, Engineering analytics, Revitalize older pump installations
Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers. Vote now (if qualified)!
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
DCS visibility, alarm management, motors and drives, robotic machining, Engineers' Choice winners
Factory automation controllers, Ethernet updates, System Integrator of the Year roundtable, Inside Process and VFDs
Robotic simulation and welding, Process building blocks, Discrete sensor advice, Virtualization advice
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. As we know, PLCs aren’t the only option for making decisions in a control loop, but they are likely why you’re here.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This article collection contains several articles on how advancements in vision system designs, computing power, algorithms, optics, and communications are making machine vision more cost effective than ever before.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Focus on power systems, process safety, electrical and power systems, edge computing in the oil & gas industry
Product of the Year winners, Pattern recognition, Engineering analytics, Revitalize older pump installations
Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers. Vote now (if qualified)!
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
DCS visibility, alarm management, motors and drives, robotic machining, Engineers' Choice winners
Factory automation controllers, Ethernet updates, System Integrator of the Year roundtable, Inside Process and VFDs
Robotic simulation and welding, Process building blocks, Discrete sensor advice, Virtualization advice
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. As we know, PLCs aren’t the only option for making decisions in a control loop, but they are likely why you’re here.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This article collection contains several articles on how advancements in vision system designs, computing power, algorithms, optics, and communications are making machine vision more cost effective than ever before.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Focus on power systems, process safety, electrical and power systems, edge computing in the oil & gas industry
Product of the Year winners, Pattern recognition, Engineering analytics, Revitalize older pump installations
Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me