Motor Drive Vector Control Using Lead Angle to Cut Arithmetic Load
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Solution Overview
Problem
Conventional motor drive control devices performing vector control with a d-axis current value always set to zero require high processing capacity, increasing system costs due to complex arithmetic operations.
Innovation Solution
A motor drive control device with a control circuit that calculates a lead angle to maintain a d-axis current value of zero, reducing the load of vector control arithmetic operations by using a q-axis current value and rotation speed to generate a drive control signal through space vector conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional vector control arithmetic operation with d-axis current value always set to zero is performed, then motor drive control is achieved, but arithmetic operation becomes complicated requiring high processing capacity device increasing system cost
Solution Approach 1:
The patent extracts and eliminates the unnecessary calculation of the d-axis current value from the conventional vector control arithmetic operation. By removing this redundant calculation step while maintaining the control effect through alternative means (using q-axis current and voltage commands directly), the arithmetic operation complexity is reduced without compromising motor drive control reliability.
Solution Approach 2:
The patent changes the control parameters by shifting focus from calculating and controlling both d-axis and q-axis current values to primarily using q-axis current value and voltage command value. This parameter change simplifies the arithmetic operations required while achieving the same motor control objective, thereby reducing processing capacity requirements and system cost.
2Productivity
If d-axis current value is always set to zero in vector control, then processing capacity requirement increases, but this approach is traditionally used for SPMSM efficiency
Solution Approach 1:
The patent implements a feedback mechanism where the q-axis current value and voltage command value are continuously monitored and used to generate the drive control signal. This feedback approach allows the system to maintain motor efficiency traditionally achieved through d-axis current control, while using simplified arithmetic operations that reduce processing capacity requirements.
Solution Approach 2:
The patent substitutes the traditional mechanical approach of calculating d-axis current value with an alternative control method that uses q-axis current and voltage command values. This substitution eliminates the need for complex arithmetic operations while maintaining the electrical control effectiveness needed for motor efficiency, thereby improving productivity without increasing processing capacity requirements.
Data Source
AI summary
A motor drive control device includes a control circuit configured to output a drive control signal for driving a motor, and a drive circuit configured to drive the motor with the drive control signal. The control circuit calculates a lead angle value δ allowing a d-axis current value Id of a two-phase rotating coordinate system to be zero with a q-axis current value Iq calculated from drive current values Iu, Iv, and Iw of a coil of the motor and rotation speed ω of a rotor of the motor. The control circuit performs a space vector conversion based on an angle σ obtained by adding the lead angle value δ and rotation angle θ and voltage command value Vref of the two-phase rotating coordinate system calculated to reduce a difference between the q-axis current value Iq and a q-axis current command value Iqref, to generate the drive control signal.