What is the difference between dv/dt filter and sine filter? Almost every voltage source inverter (VSI) has some kind of inverter output filter. Design of the output filter has major impact on the drive characteristic and performance. For this post we have picked two key representatives. They are widely used Read more…
How are the motor load points defined? Customer is often interested in defining the performance (e.g. losses and efficiency) of a motor drive for specific operating points. But how are the motor load points defined? Over the years working with variable speed inverter fed motors I come across this topic. Read more…
What is SSTI and why it shall be studied? In this short post we provide a little introduction into what is SSTI and how it can be linked to variable frequency drives (VFD). The post also explains the motivation for studying such phenomenon. What is SSTI? SSTI stands for sub-synchronous Read more…
What is the definition of low voltage and medium voltage VFD? We all probably know that variable frequency drives (VFD) can be classified into two groups based on their voltage: low voltage VFD and medium voltage VFD. But what voltage do we talk about? Let’s shortly explain… IEC 61800 distinguishes Read more…