Inverter Voltage Drop Characterisation Considering Junction Temperature Effects

Dead-Time Inverter Voltage Drop in Low-End Sensorless FOC Motor Drives

“…These methods are generally more intricate as they involve real-time estimation of the voltage drop, necessitating intensive computational processes (methods such as those described in [18], which employ online optimization algorithms that require significant processing power). In addition to online methods, some studies propose the self-commissioning characterization of the inverter during startup or when the motor is at a standstill [19][20][21][22]. In these works, the non-linearities of the inverter are estimated and stored in Look-Up-Tables (LUT) for subsequent compensation in the abc-reference frame.…”

“…Although the above works target motor drive applications, they do not consider lowend sensorless applications under dynamic conditions. Furthermore, achieving complete compensation of the inverter voltage drop is challenging due to nonlinearities such as parasitic capacitances [15], temperature variations [19], DC-link voltage variations, and so on. Therefore, as shown in this work, direct compensation at the abc-reference frame in low-end sensorless applications may be inadequate, resulting in suboptimal performance at low speeds due to insufficient compensation during dynamic conditions.…”

“…This additional part, hereafter called inverter voltage drop, is uncontrolled and depends on DC-link voltage, PWM dead time, PWM frequency, and the direction of the corresponding phase current. The resistance of switching elements (rds-on) and non-linearities such as parasitic capacitance [15] and switching elements junction-temperature [19] also affect voltage drop; however, they are not considered in this study. To distinguish the uncontrolled part from the inverter output voltage controlled via the FOC, we used the following two conventions: The term v xo , FOC (t)* represents the component controlled via the FOC scheme, and the term v xo,drop (t)* represents the uncontrolled voltage drop component:…”

Dead-Time Inverter Voltage Drop in Low-End Sensorless FOC Motor Drives

“…These methods are generally more intricate as they involve real-time estimation of the voltage drop, necessitating intensive computational processes. In addition to the online methods, some studies propose the selfcommissioning characterization of the inverter during startup or when the motor is at a standstill [18][19][20]. In these works, the non-linearities of the inverter are estimated and stored in Look-Up-Tables (LUT) for subsequent compensation in the abc-reference frame.…”

“…Although the above works target motor-drive applications, they do not consider low-end sensorless applications under dynamic conditions. Furthermore, achieving complete compensation of the inverter voltage drop is challenging due to nonlinearities like parasitic capacitances [15], temperature variations [18], DC-link voltage variations and so on. Therefore, as will be shown in this work, in low-end sensorless applications the direct compensation at abc-reference frame might prove inadequate, resulting in suboptimal performance at low speeds because of the insufficient compensation during dynamic conditions.…”