The Internet of Things is changing logistics
March 2021
Level Measurement & Control
A focus on application engineering allows Trafo Power Solutions to supply customised dry-type transformers for a range of sectors including renewable energy.
“We begin at the proposal stage by engaging closely with the customer about the exact application and electrical load,” says David Claassen, managing director of Trafo Power Solutions. “This means that every project gets its own transformer design, so that it is fit for purpose.”
In the case of renewable energy applications, for example, there are some very specific demands that need to be accommodated. A solar power generating plant presents a situation in which a transformer will be energised from 0% to 100% on a daily basis.
“This leads to wide fluctuations in temperature inside the transformer which, in turn, causes the resin around the windings to expand and contract considerably,” says Claassen. The windings in dry-type transformers are insulated in a cast resin or epoxy material, rather than oil, and rely on air movement for cooling.
“Such fluctuations could result in the resin cracking, so the design must specify the appropriate class of insulation to cope with these conditions. We can design our windings for either Class F or Class H insulation. In addition, the mixture of the resin is specially formulated to accommodate the duty cycle specific to renewable energy applications.”
The standard design – using Class F – can deal with temperatures up to 155°C. For many of Trafo Power Solutions’ low-voltage and high-voltage installations around Africa, the design includes a resin mix to Class H specifications. This gives it the capacity to withstand temperatures of up to 180°C.
Another aspect that needs to be considered for renewable energy applications is the non-linear load that inverters add to the mix. The transformers need to be designed with a K-factor much higher than used for standard distribution type loads, as well as the addition of an electrostatic shield between the primary and secondary windings to eliminate potentially damaging leakage currents.
Claassen notes that dry-type transformers are being increasingly specified for demanding applications such as renewable energy plants, instead of conventional oil transformers.
“With an oil-cooled unit, the temperature fluctuation arising from these rapid and regular energising and de-energising cycles brings its own challenges,” he adds. “In particular, it causes more gases to be emitted within the transformer tank, which leads to a variety of problems.”
The cast resin material used in Trafo’s dry-type transformers meets the specifications of the International Electrotechnical Commission (IEC) for fire class F1. The units therefore present minimal fire risk, allowing them to be used indoors safely, and without environmental protection like bund walls for potential oil spills.
Claassen says dry-type distribution transformers are fast becoming a more suitable alternative to oil transformers, especially in the distribution power range between 50 kVA and 10 MVA, although Trafo Power Solutions is able to supply dry-type transformers up to a power rating of 25 MVA
Further reading:
A new era in radiometric level and density measurement
Mecosa
Level Measurement & Control
The LoopSeries LB 430 radiometric detector from Berthold Technologies has a revolutionary power solution and sets new standards in level and density measurement.
Read more...
Level measurement of an acid dosing tank at a WWTP
Level Measurement & Control
Ferric chloride and other acids are essential chemical substances in water and wastewater treatment. To control the dosing of acid solutions, an Australian wastewater treatment plant uses a special container to store, mix and add these chemicals. The company opted in favour of KROHNE’s OPTIWAVE 1540 radar level transmitter
Read more...
Level measurement of leachate from sewage sludge humification
Level Measurement & Control
A municipal utility in eastern Germany operates a state-of-the-art wastewater treatment plant with sustainable sludge treatment. The ultrasonic signal was being partially deflected by the wind, leading to frequent false measurements and inefficient process workflows. The problem was solved by replaced the ultrasonic level sensor with KROHNE’s OPTIWAVE 1540 non-contact radar.
Read more...
Groundbreaking measurement system
Mecosa
Level Measurement & Control
Berthold Technologies has launched the LoopSeries LB 430, an innovative, industry-leading measurement system designed to enhance operational efficiency with advanced level, density, and level switch capabilities.
Read more...
Level measurement of a water sump at a sewage treatment plant
Level Measurement & Control
A major city council in South East Queensland, Australia maintains and operates a wastewater treatment plant (WWTP) for municipal, industrial and agricultural wastewater. Due to the risk of flooding, the water sump must be continuously monitored. The solution is KROHNE’s OPTIWAVE 1540 radar level transmitter.
Read more...
Simplicity in measurement
Endress+Hauser South Africa
Level Measurement & Control
Endress+Hauser’s new 80 GHz compact radar range is designed to help customers reach their compliance targets through simple yet efficient measurement solutions.
Read more...
Case History 196: Unstable condensate level control.
Michael Brown Control Engineering
Editor's Choice Level Measurement & Control
The operators in a petrochemical refinery were having great trouble in trying to stabilise the condensate level in a vessel, and this was adversely affecting other loops downstream. Several unsuccessful attempts had been made to retune the controller.
Read more...
Non-contact level measurement for hygienic and industrial applications
ifm - South Africa
Level Measurement & Control
The LW2720 radar level sensor from ifm sets new benchmarks for speed and accuracy.
Read more...
Level measurement in oil storage
VEGA Controls SA
Level Measurement & Control
Measuring the level of crude oil in storage is essential for safe and efficient operations. VEGA offers solutions that effectively address the challenges, ensuring precise and consistent level measurements in crude oil storage facilities. VEGA’s sensors offer reliable data on the volume, level and pressure of all types of media. Accurate level measurement is complicated by crude oil thermal expansion properties, particularly in lighter oil grades.
Read more...
Cloud-based inventory management
Endress+Hauser South Africa
Level Measurement & Control
Netilion is an award-winning cloud-based IIoT ecosystem designed for industrial processes. It connects the physical and digital worlds to send valuable information from the field straight to your phone, tablet or other device.
Read more...
printer friendly version