Current Transformer Sensors Expanding into Network Power

The use of current transformer sensors to measure and enhance network power quality is growing. These are essential in heavy current measurement as they offer reliability, accuracy and the guarantee of extended service life. Power quality is increasingly a factor as loads controlled by nonlinear, as opposed to linear, electronic components are becoming more prevalent in home and industry. This means that the voltages and currents in the power systems feeding these loads are rich in harmonics, which can create the risk of distortion.

Excessive harmonics in an AC power system are capable of overheating transformers. This enables electromagnetic “noise” in the form of radio emissions, which can be difficult to pinpoint, to interfere with sensitive electronic equipment and reduce electric motor horsepower output. Key players in the current transformer sensors market include Murata, Omron, Littelfuse, Kemet, Phoenix Contract, TT Electrics, Vishay, API Technology, EPCOS/TDK, Hammond, Vacuumschmelze, Pulse and Triad Magnetics.

Camille Bauer Presents New Current Transformers

In January, the Nuremberg Germany based developer and producer of industrial measurement technology, Camille Bauer Metrawatt AG, announced the presentation of a new series of current transformers for current quality analysis. It described the new generation of converters, the XCTB, XKBU and XKBR series as, “guaranteeing trouble-free operation even in the harmonic band up to 20 kHz.” But in order to avoid measurement errors as much as possible when there are harmonic oscillations, the measurement system is limited to 1 kHz of the monitored frequency spectrum.

Application example of a qualified mains quality analysis in combination with a residual current monitor and an earth conductor current monitor 

Credit: Camille Bauer

In UPS networks, data centres, production facilities, airports, etc., a residual current monitor (RCM) can be placed as a protective device. However, these RCM systems are vulnerable. The company said its solution is a measuring system with qualified sensors. “Residual currents, as well as ground conductor currents, can be measured and evaluated in the same application with the LINAX PQ series. With a measuring device from the LINAX PQ series and the sensors matched to it, various applications can be carried out at the same time as well as very cost-effectively, with constant high accuracy and compliance with standards in the overall system,” said the company.

Unipower AB Wins Power Quality Contract to Finnish System Operator

Unipower AB, the Swedish based developer of power quality and smart-grid solutions, has started to deliver on a contract to Fingrid Oyj, for the delivery and support of a power quality system. The contract, which was signed in 2019, is due for completion in 2025. It includes delivery of a large number of power quality meters, the management system PQ Secure, as well as maintenance and support. Fingrid is the system operator in Finland with the responsibility of the transmission grid, which consists of more than 14,000 kilometres of power lines, 110,220 and 400 kilovolts.

The PQ Secure system from Unipower will continuously monitor the power quality all over Finland and make the information easily foreseeable and assessable to Fingrid. Beside the real time monitoring, statistical evaluation and reporting Fingrid will also utilise the alarm functionality, which will give the user a notification if an event is detected. “That Unipower now signed another agreement with a Transmission System Operator is very positive and I do look forward to start transfer our know-how in power quality to Fingrid. It has been a fierce competition and the fact that we won proves that the functionality, human interface and data efficiency we provide is unique and valued by the user,” says Peter Andersson, CEO.

Aclara Smart Grid Solutions

A recently published application guide from Aclara, now part of the Hubbell Power Systems' family of brands and supplier of sensor-enabled analytics of smart infrastructure solutions (SIS), says that smart grid sensors and sensor-enabled analytics are powerful tools that can increase electric utilities ‘situational awareness’ on the condition of their distribution networks. "Many utilities using smart grid sensor technology have uncovered situations that could cause sparks...these show up via sensors and can be corrected before more serious issues arise," remarked Kevin Corcoran, director of product management, Aclara. "In addition, utility planners and response personnel also can deploy and use sensors to aid in planning for Public Safety Power Shutoff events," he concluded.

The availability of real-time data and insights from these sensors is increasingly important. Easy to deploy, smart grid sensors are also ideal for providing load and voltage data in near real-time so that utilities can maintain situational awareness around problem areas. This allows for emergency switching and load transfers to take place while avoiding other issues that might arise due to the overloading of other equipment. Aclara Grid Monitoring platform solution continually monitors lines for abnormal events. And the combination of this and its Grid Monitoring platform can help utilities throughout all stages of fire mitigation.

Elspec ‘Black Box’ PQ Solution

Meanwhile, Elspec Ltd, the Tel Aviv Stock Exchange listed power quality solutions and services provider, has developed a number of recent solutions. In France, It has supplied 10 Equalizers systems for 10 wind farms. Upon completion of commissioning the wind farm, a failure in the SWM (a part of the Equalizer) was successfully reported on a weekly basis. The Elspec Black Box (EG4K), installed on each of the turbines, was able to trace the source of the failure.

Outlook

A recent study into the Smart Grid Market’ projects the market growing at a CAGR of 12.4% to reach $169.18 billion by 2025. A key driver of the market is the increasing use of technology to improve energy conservation, reliability and consumption efficiency.