Phase Compensation for Motor Current Control Stability
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Solution Overview
Problem
Existing motor control systems face challenges in accurately controlling motor currents due to phase delays and parameter fluctuations, leading to oscillations and instability in the current control loop, which restricts the ability to increase current loop gain and band width.
Innovation Solution
The motor control apparatus incorporates a phase compensation disturbance current observer that compensates for phase delays and disturbances by using a delay system model and observer gains to output an estimated current that is phase-advanced and disturbance-corrected, thereby stabilizing the current control loop and improving responsiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If current loop gain and bandwidth are increased to improve response speed, then productivity is improved, but phase delays and parameter fluctuations cause oscillations and instability
Solution Approach 1:
The phase compensation part performs preliminary phase adjustment on the feedback signal before it enters the current control loop. By advancing the phase of the feedback current signal in advance, the system compensates for the inherent phase delays in the control path, allowing higher gains and bandwidths to be used without causing instability or oscillations.
Solution Approach 2:
The patent implements a feedback mechanism where the actual motor current is detected and fed back through the phase compensation part. This closed-loop feedback allows the system to continuously monitor and correct phase deviations, maintaining stability even when operating at higher current loop gains and bandwidths that would otherwise cause oscillations.
2Manufacturing precision
If phase compensation is applied to improve current control accuracy, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The phase compensation part acts as an intermediary component between the current detection part and the current conversion part. It specifically addresses phase delay issues without requiring complete redesign of the entire control system, thereby improving current control accuracy while adding only moderate complexity through a dedicated phase adjustment module.
Data Source
AI summary
This disclosure discloses a motor control apparatus including a current conversion part, a voltage control part, a current detection part, and a phase compensation part. The current conversion part generates a voltage command on the basis of a current deviation between a current command and an estimated current. The voltage control part controls an output voltage to a motor. The current detection part detects a motor current. The phase compensation part inputs the detected motor current and the voltage command and outputs, as the estimated current, the motor current in which a delay in phase of the motor current relative to the current command has been compensated.