You have provided quite a long list of manufacturers of Medium Voltage Drives manufacturers. All of them are, however, big players on the electric drives market. Have you ever heard about any small or medium size company that would be manufacturing MV Drives for motor applications, renewable energy applications (wind, wave, solar etc.) and possibly other? I am especially interested in multi-level NPC or cascaded inverters.

Aleksandra Jargot

Please add RXPE to the list of manufacturers

Regards

Steve

First of all I would like to gather base information like nominal parameters and essential features of drives present on the market and provide links to available documentation. Then I would like to compare specific approaches to the issues that can be met in the drive design.

The PF and efficiency throught out the whole speed range is surely one of them. I have not seen comprehensive publication or presentation in this field. There isn’t clear standard how efficiency should be calculated. Most of manufacturers show in specifications efficiency value at rated load. You have to consider if is it efficiency of converter only or converter + transformer or converter + transformer + all auxiliary devices. At the moment I can give you only two links:

• TM GE – Medium Voltage Drives Evolution – you will find there semiconductor devices efficiency comparison over the load range
• Rockwell Automation – Medium Voltage Drives in Industrial Applications – PF over the load power for different rectifier topologies

These are not strict technical presentations but some conclusions can be made.

Best regards,

Paweł

1. PF over the speed/load range for CSI PWM (Rockwell) versus VSI PWM solutions (other manufacturers).

2. Overall systems efficiency comparisons (from intput through inverter output) of CSI PWM topology versus a VSI PWM design (pick a manufacturer) this over frequency range of say 30 Hz to 60 Hz and assuming centrifugal load.

Kind regards,

Steve Lacki