Vector Controller Magnetization-Voltage Command Zeroing for Motor Stability
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Solution Overview
Problem
Conventional sensorless vector control for electric motors experiences interference between PI controllers, making stable control difficult due to the calculation of magnetization-voltage command values affecting angular velocity calculations.
Innovation Solution
A driving apparatus with a vector controller that sets the magnetization-voltage command value to 0 and uses a V/ω pattern to determine the target-output-voltage value based on angular velocity, eliminating the need for one PI controller and stabilizing control operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensorless vector control is implemented to prevent synchronous motor from losing synchronism, then motor control stability is improved, but interference between PI controllers occurs making stable control difficult
Solution Approach 1:
The patent extracts and removes the magnetization-voltage control section from the control system. Instead of using a PI controller for magnetization-voltage control, the system directly calculates the magnetization-voltage command value based on the relationship between output voltage and angular velocity, eliminating the source of interference between controllers while maintaining the necessary control functionality
Solution Approach 2:
The patent changes the control parameter relationship by establishing a direct functional relationship between output voltage and angular velocity. By defining the magnetization-voltage command value as a function of these parameters rather than using a feedback PI controller, the system achieves stable control without the interference that occurs when multiple PI controllers interact
2Measurement precision
If magnetization-voltage command value is calculated by PI controller to maintain magnetization current, then magnetization control precision is improved, but interference with angular velocity calculation occurs
Solution Approach 1:
The patent removes the magnetization-voltage control section that was causing interference with angular velocity calculation. The magnetization-voltage command value is now directly calculated from output voltage and angular velocity relationships rather than being controlled by a separate PI controller, eliminating the harmful interaction while preserving control precision
Solution Approach 2:
The patent segments the control functions by separating the calculation of magnetization-voltage command value from the angular velocity calculation process. The magnetization-voltage command is derived independently through direct parameter relationships, preventing interference with the velocity calculation while maintaining precise magnetization control
Data Source
AI summary
The present invention relates to a driving apparatus which performs vector control based on an output current of an inverter. The driving apparatus of the present invention includes a vector controller (11) for transforming three-phase output currents of an inverter (10) into a torque current and a magnetization current, and controlling the torque current and the magnetization current. The vector controller (11) includes a torque-voltage control section (21) for determining a torque-voltage command value based on a deviation between a torque-current command value and the torque current, a magnetization-voltage output section (23) for outputting 0 as a magnetization-voltage command value, a target-magnetization-current determination section (26) for determining a magnetization-current command value based on a deviation between a torque-voltage command value and a target-output-voltage value, and a target-output-voltage determination section (27) for determining the target-output-voltage value.