A Look Inside Maxwell Technologies’ High-Voltage Capacitor Lab
October 17, 2016 | Jessica Baris, Communications Specialist and Copywriter
The high-voltage laboratory is an impressive space. Stepping past the entrance gate, one’s eyes are drawn straight to the high-voltage transformer’s metallic dome. At nearly 10 meters (33 ft.) tall, the transformer towers over the lab like a technological giant.
For over 100 years, Maxwell Technologies’ high-voltage CONDIS® capacitors have evolved with each sweep of change in the utility industry. The high-voltage laboratory, based at Maxwell’s manufacturing site in Switzerland, is where the capacitors pass the final tests before they are installed in the field to perform their ultimate work on the utility network. The lab’s team of engineers and technicians stay focused on delivering the long-standing value of quality.
Minh Duc Vo starts his mornings by walking the manufacturing line, getting a sense of the day’s schedule and the pace of production. Vo, Maxwell’s high-voltage test engineering manager, oversees the high-voltage laboratory, where each day approximately 100 capacitors are tested for quality. When
electrical voltage is applied to the capacitors, Vo is able to analyze their capacitance value, partial discharge level, and capacitance loss tangent.
"The high-voltage transformer elevates the voltage from the network from 400 volts up to 1 million volts," Vo said. "We apply
electrical voltage that is similar to what the customer will see on their network. Our high-tech laboratory, and the testing processes we have in
place, is how we ensure that
CONDIS capacitors deliver the quality and reliability our customers need."
CONDIS capacitors can be found in a variety of utility networks across the globe and operate in challenging climates. The most common application is grading capacitors for circuit breakers. Vo said that
CONDIS grading capacitors have the important job of distributing the voltage between chambers in circuit breakers and preventing overvoltage.
Another application is transient recovery voltage (TRV). "Overvoltage requires the customer to oversize network components," said Vo. "When
CONDIS TRV capacitors are applied, the recovery voltage is smoothed, and the capacitor prevents components on the network from being damaged by overvoltage. The capacitor makes it possible for the customer to keep the circuit breaker at a manageable size and to optimize the dimensions of the circuits."
Grading and TRV capacitors, along with all other
CONDIS high- and medium-voltage capacitors, are tested in the lab before delivery to customers. "Our technology is always evolving," said Vo. "We are continuously improving our test equipment and our products to stay in stride with the ever-changing utility landscape."
In 2017, a new 1,200 kV gas-insulated switchgear (GIS) test installation will arrive as the next upgrade to the laboratory. Vo said the new GIS lab will be a prototype for one of the highest voltage test systems available in the world.
"Our customers require higher voltages as changes occur in the utility networks and as end-user demands increase," Vo said. "The new GIS test installation will enable us to provide capacitors for some of the most demanding applications in the world. The Chinese market has 1,000 kV transmission lines and the Indian market has 1,200 kV lines. The new GIS system will make it possible for us to serve those customers."
When asked to share any final thoughts about his work in the lab, Vo pointed out a common misconception: "People are often surprised that the tests are so silent. There are no discharges or lightning bolts. We want to avoid Faraday’s experiment," he said with a chuckle. "Most days are quiet, and it’s synonymous with a good day."
Communications Specialist and Copywriter
About this author
Jessica A. Baris is communications specialist and copywriter at Maxwell Technologies and enjoys telling a good story. Her background includes writing and editing for the high-tech, construction, and meetings and conventions industries. A San Diego native, Jessica earned a Master of Arts in rhetoric and writing from San Diego State University and a Bachelor of Arts in linguistics from the University of California, San Diego.
TRV Capacitors - AIS
In air-insulated switchgears (AIS), transient recovery voltage (TRV) capacitors are installed phase-to-ground. They decrease the oscillation frequency and the rate of rise of recovery voltage (RRRV) of TRV, which occurs during initiation or interruption of current flow. TRV capacitors are thus installed to increase breaking power of the circuit breaker.
TRV Capacitors - GIS
Gas-insulated switchgear (GIS) circuit breakers for tough environments with extreme temperature variations, dust, pollution or confined space may use transient recovery voltage (TRV) capacitors. They decrease the oscillation frequency and the rate of rise of recovery voltage (RRRV) of TRV which occurs during initiation or interruption of current flow. TRV capacitors are thus installed to increase breaking power of the circuit breaker.
Grading Capacitors - AIS
In air-insulated switchgears (AIS), grading capacitors ensure a uniform distribution of the voltage across the breaking chambers of the live tank circuit breaker.
Grading Capacitors - GIS
Gas-insulated switchgear (GIS) circuit breakers for tough environments with extreme temperature variations, dust, pollution or confined space use grading capacitors to ensure a uniform distribution of the voltage across the breaking chambers.
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