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Reference Number: AA-01933// Views: AA-01933// Created: 2020-07-23 13:39:17// Last Updated: 2020-07-23 19:57:26 eFPGASIM How to calculate RC Snubber values for coupling inverter and PMSM
We use RC snubbers which allow for proper coupling of the inverter to the motor. The computation of the R_Snubber and C_Snubber values can be done as follows: 1. Assume R_Snubber = 100 ohms and choose C_Snubber such that R_Snubber*C_Snubber = 5*(Time Step of the FPGA model/eHS) 2. Run the simulation to check whether it is stable without PWM gating signals. 3.If the losses are too high, you can double the R_Snubber value and reduce the C_Snubber value by half. 4.If the losses are acceptable but the simulation is not stable, reduce the R_Snubber value by half and double the C_Snubber value unitl the simulation is stable. (Please note the exact connection of the RC Snubbers will have an impact on the calculations, for example, if there is a star connection to a floating node, the snubbers will charge only to 0.5*Vdc) |