Hello All,
I am currently working on designing and building a basic Three phase AC motor drive using V/F and PWM. I will be controlling the drive with a FPGA and I am ready to begin testing with hardware. The motor I am currently designing for is 2.2Kw 3HP spindle motor that is rated 24,000RPM @ 400Hz 220V.
I am using and Fairchild Semi SME6G15US60 IGBT module for switching the output three phase. With a International Rectifier IR2136 3-phase bridge driver for driving the IGBT's.
I am running into many questions when considering power supply design. I need to rectify the incoming line power and feel that isolation from mains is not a viable part of the design for the following reasons.
-Isolation Transformers are too large and expensive when using this much power.
-Boost / Buck regulator would be nice but too inefficient.
-The DC bus, three phase output, and other non-isolated voltages will be enclosed once the project is finished. Not accessible for touching...
-The logic side of the drive can be opto-isolated from the power electronics. So all logical inputs / outputs, controls, and processing can be run off a separate isolated power supply.
I feel confident in the safety of the design however I understand the potential danger of the situation and would like some feedback if possible.
Thanks,
Tyler Grandahl
I am currently working on designing and building a basic Three phase AC motor drive using V/F and PWM. I will be controlling the drive with a FPGA and I am ready to begin testing with hardware. The motor I am currently designing for is 2.2Kw 3HP spindle motor that is rated 24,000RPM @ 400Hz 220V.
I am using and Fairchild Semi SME6G15US60 IGBT module for switching the output three phase. With a International Rectifier IR2136 3-phase bridge driver for driving the IGBT's.
I am running into many questions when considering power supply design. I need to rectify the incoming line power and feel that isolation from mains is not a viable part of the design for the following reasons.
-Isolation Transformers are too large and expensive when using this much power.
-Boost / Buck regulator would be nice but too inefficient.
-The DC bus, three phase output, and other non-isolated voltages will be enclosed once the project is finished. Not accessible for touching...
-The logic side of the drive can be opto-isolated from the power electronics. So all logical inputs / outputs, controls, and processing can be run off a separate isolated power supply.
I feel confident in the safety of the design however I understand the potential danger of the situation and would like some feedback if possible.
Thanks,
Tyler Grandahl