1. What are the causes for unbalancing in dc-link capacitor voltages practically.

2. If the supply and load are balanced, will there any unbalance in dc-link voltages across the capacitors ??

3.What is the percentage of voltage unbalancing across the capacitors acceptable ??

4. What is the effect of these unbalance in dc-link capacitor voltages on the motor load (either speed or torque)??