Sensorless Motor Control Using Pre-Alignment Stator Resistance Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensorless motor control methods for washing machines require time-consuming initial position alignment of the rotor, which increases the time to start the motor and can lead to reduced net acting ratio due to increased inertia of the driven object.
Innovation Solution
A motor control method and apparatus that estimates the stator resistance before aligning the rotor's position, applying a first input voltage to estimate the stator resistance and then a second input voltage to estimate the rotor's position, thereby reducing the time required for initial position alignment and improving resistance estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If initial position alignment is performed before motor startup, then starting characteristics are stabilized, but the time required for motor startup increases
Solution Approach 1:
The patent applies preliminary action by performing stator resistance estimation before the main motor startup process. The control apparatus estimates stator resistance during a pre-alignment phase using a first input voltage, then uses this estimated resistance value to optimize the subsequent startup process. This preliminary estimation enables the system to skip time-consuming iterative alignment procedures during actual startup, thereby reducing overall startup time while maintaining starting characteristics stability.
2Reliability
If initial position alignment is performed, then detection performance is stabilized, but the net acting ratio of the washing machine is lowered
Solution Approach 1:
The patent performs stator resistance estimation as a preliminary action before motor startup. By estimating the stator resistance value in advance using a dedicated estimation routine with first input voltage, the system establishes accurate detection parameters beforehand. This preliminary estimation ensures detection performance stability during the actual washing operation without requiring continuous position alignment procedures, thereby maintaining high net acting ratio and productivity.
3Measurement precision
If stator resistance is estimated before position alignment, then resistance estimation accuracy is improved, but additional control steps are required
Solution Approach 1:
The patent merges the stator resistance estimation process with the existing initial position alignment routine. The control apparatus integrates the estimation of stator resistance into the pre-alignment phase, using the same control period and input voltage application infrastructure. By combining these functions, the system achieves accurate resistance estimation without adding significant control process complexity, as both operations share common hardware and control structures.
Data Source
AI summary
Disclosed is a motor control apparatus and a motor control method to estimate a stator resistance of a motor for sensorless control of the motor.