Inverter Apparatus Rotor Angle Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inverter apparatuses for three-phase brushless motors lack a configuration that effectively examines the conduction state without causing misalignment of the rotor's angular position before and after the examination process, leading to potential accumulative changes in the mechanical angle and position of the movable section.
Innovation Solution
An inverter apparatus with three high-voltage and three low-voltage switching elements, an opening and closing control unit that sequentially forms four specific combinations to rotate the electrical angle by 120° in each direction, and a detection unit to ensure all switching elements are examined, minimizing rotor misalignment by determining combinations based on the rotor's acquired angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the inverter apparatus performs conduction state examination by sequentially closing switching element combinations, then the conduction state of all switching elements can be detected, but the electrical angle changes during the process causing misalignment of the rotor's angular position before and after examination
Solution Approach 1:
The control unit pre-calculates and stores multiple candidate combination sequences in advance, each designed to return the electrical angle to its original value. During conduction examination, the appropriate pre-designed sequence is selected and executed, preventing angular position drift before it occurs rather than correcting it afterward.
Solution Approach 2:
The control unit acquires the current rotor angular position in advance and uses this information to select the most appropriate combination sequence from stored candidates. This preliminary action ensures that the examination process starts with optimal parameters already determined, minimizing angular deviation throughout the examination.
2Ease of operation
If the inverter apparatus uses a fixed combination sequence for conduction examination, then the examination process is simple to implement, but it cannot adapt to different rotor positions causing accumulative changes in mechanical angle
Solution Approach 1:
The system transitions from a static fixed combination sequence to a dynamic adaptive sequence selection mechanism. The control unit dynamically selects among multiple pre-stored combination sequences based on the actual rotor position, allowing the examination process to adapt to different starting conditions while maintaining operational simplicity through automated selection.
Solution Approach 2:
The system changes the parameter of combination sequence selection based on rotor position feedback. Instead of using a single fixed sequence, the control unit varies the selected sequence according to the measured rotor angle, optimizing the examination process for each specific operational condition while keeping the underlying sequence structures pre-defined and simple.
Data Source
Figure 1
Figure 2~3
Figure 4(a)~4(d)
AI summary
An inverter apparatus (10) includes: an inverter (20) including three high-voltage side switching elements (SH, SHU, SHV, SHW) and three low-voltage side switching elements (SL, SLU, SLV, SLW) respectively provided in three phases one by one, and driving a three-phase brushless motor (1); an opening and closing control unit (33) performing controlling so as to cause an electrical angle of the motor to pass through an angle corresponding to a first combination, to rotate twice by 120° each time to one side in a rotary direction, and to rotate once by 120° to the other side in the rotary direction thereafter, by sequentially closing four combinations each of which is formed with one among the high-voltage side switching elements and one among the low-voltage side switching elements; and a detection unit (32) detecting a conduction state of a circuit including the closed high-voltage side and low-voltage side switching elements, wherein all the high-voltage side and low-voltage side switching elements are closed at least once in the four combinations.