VFDs reach milestone
Siemens has achieved a new record with the world’s largest high-speed variable frequency drive.
Siemens Energy & Automation Inc. has announced its Siemens Robicon Perfect Harmony Drives have reached a technical milestone with the introduction of a 8 MW variable frequency drive (VFD) that operates with an output frequency of 500 Hz, making it the world’s largest high speed VFD.
This milestone is just the latest for the series of high-speed Siemens Robicon Perfect Harmony drives. While the basic VFD topologies have been limited to output frequencies in the 120 to 200 Hz range, Siemens has already manufactured and installed drives that operate at frequencies between 315 and 400 Hz.
The Siemens Robicon Perfect Harmony power-cell based multilevel arrangement provides a unique topology that allows operation up to 500 Hz, regardless of the VFD power rating. Tests on the VFD control were set to operate the motor in encoderless vector control with 920 Hz IGBT switching frequency, resulting in an effective switching frequency of 9.2 kHz and a sample frequency of 9.2 kHz. This test drive demonstrated very high quality waveform to the motor with low harmonic distortion.
This latest VFD will be used to drive permanent-magnetic motors, such as those found in natural gas processing and transportation applications that require high-speed compression.
Case Study Database
Get more exposure for your case study by uploading it to the Plant Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.
These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.
Click here to visit the Case Study Database and upload your case study.
Annual Salary Survey
In a year when manufacturing continued to lead the economic rebound, it makes sense that plant manager bonuses rebounded. Plant Engineering’s annual Salary Survey shows both wages and bonuses rose in 2012 after a retreat the year before.
Average salary across all job titles for plant floor management rose 3.5% to $95,446, and bonus compensation jumped to $15,162, a 4.2% increase from the 2010 level and double the 2011 total, which showed a sharp drop in bonus.