The management of currents flowing through the motor driving the electronics becomes critical to ensure overall system efficiency and reliability. Indeed, motor currents may exceed tens of amperes in such applications, which leads to increased power dissipation inside the inverter module, reducing its efficiency. More power to the electronic components of the inverter also results in higher temperatures, which could consequently degrade their performance over time and/or cause sudden breaks if going above maximum allowed ratings.
Several electronic components widely used in motor control systems are very sensitive to operating ambient temperature. For example, electrolytic capacitors typically used to stabilize the main supply voltage of the inverter are guaranteed by the manufacturer for a minimum number of hours without failures.
Consequently, the optimization of thermal performance, in combination with a compact form factor, is a key aspect of the inverter design phase that can hide pitfalls if not properly addressed, resulting in underperforming products.
The current density in the PCB is also a critical factor when the current flows between different planes through via holes. Overstressing a single via connection due to poor placement could result in a sudden failure during operation, making analysis of this issue critical as well.