| Title |
Implementation of Speed Limitation Controller Considering Motor Parameter Variation in High Speed Operation |
| Authors |
김경훈(Kim, Kyung-Hoon) ; 윤철(Yun, Chul) ; 권우현(Kwon, Woo-Hyen) |
| DOI |
https://doi.org/10.5370/KIEE.2017.66.11.1584 |
| Keywords |
Motor parameter compensation ; PMSM ; Stator resistance estimation ; Flux weakening operation ; Inverter voltage error |
| Abstract |
This paper presents a implementation method of reliable speed limitation controller considering motor parameter variation in high speed operation. In spinning process of drum washing machine, speed increase has to be limited when unallowable imbalance mass is detected. Otherwise, severe noise and vibration can happen because noise and vibration are proportional to imbalance mass. To detect imbalance mass, d-axis current magnitude is used. However, we have to compensate for back-emf and power supply variation by means of detecting them because d-axis current is affected by both of them. On the other hand, we have to carefully estimate back-emf because back-emf is affected by stator resistance variation and inverter voltage error. Stator resistance variation can happen by manufacturing process for mass production or temperature variation in running. And there are inverter voltage errors between command voltage from micro-computer to inverter and real voltage from inverter to motor because of rising and falling time delay and turn-on resistance of power semiconductor switch. To solve this problem, we propose 2-step align current injection method which is to inject step-wise current right before starting. By this method, we can simply obtain stator resistance by ratio of voltage without inverter voltage error and current, and we can measure inverter voltage error. So we can obtain more exact model current, and then by simple calculation with compensation gain, we can estimate more accurate motor back-emf. We show that this method works well. It is verified through experiments. |