Open-End Winding Inverter Control for Common-Mode Current Suppression
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Solution Overview
Problem
The open end winding type motor driving technique struggles to control zero-phase component voltage, leading to the generation of common mode currents that cause losses and potential damage due to the difference in zero-phase component voltages between inverters connected to both ends of the motor windings.
Innovation Solution
A motor driving apparatus is designed with a controller that generates limited pole voltage commands and adjusts zero-phase component voltages to ensure both inverters have the same zero-phase component voltage, using space vector pulse width modulation and inverse Clarke/Park transformation to distribute voltage commands effectively, thereby eliminating the difference in zero-phase component voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If open end winding type motor driving technique is used to increase phase voltage and improve voltage utilization rate, then output power is improved, but zero-phase component voltage cannot be controlled and common mode current is generated
Solution Approach 1:
The patent changes the control parameters by introducing zero-phase component voltage control and common mode voltage control to the open end winding motor driving system. By adjusting these voltage parameters and using space vector pulse width modulation with inverse Clarke/Park transformation, the system achieves both high output power and suppression of common mode current.
2Force
If more windings are added to increase maximum torque, then torque capability is improved, but voltage utilization rate section moves away from low torque operating point, deteriorating fuel efficiency
Solution Approach 1:
The patent employs dynamic voltage control through space vector pulse width modulation that can adaptively adjust the voltage utilization rate according to operating conditions. By using inverse Clarke/Park transformation and controlling pole voltage commands, the system dynamically optimizes the voltage utilization rate to match the operating point, achieving both high torque capability and improved fuel efficiency.
3Device complexity
If zero-phase component voltage is not controlled in open end winding type motor, then device complexity is reduced, but circulating current is generated causing motor efficiency reduction and potential damage
Solution Approach 1:
The patent implements feedback control by using inverse Clarke/Park transformation to calculate and control the zero-phase component voltage based on the motor's operating state. This feedback mechanism continuously monitors and adjusts the pole voltage commands to maintain proper zero-phase voltage control, preventing circulating current while ensuring system reliability.
Data Source
AI summary
A motor driving apparatus of driving a motor including a plurality of windings respectively corresponding to a plurality of phases is disclosed. The motor driving apparatus includes a first inverter including a plurality of first switching elements and connected to a first end of each of the windings, a second inverter including a plurality of second switching elements and connected to a second end of each of the windings, and a controller electrically connected to the first switching elements and the second switching elements and configured to generate limited pole voltage commands for space vector pulse width modulation based on preset voltage commands of the motor and to distribute the limited pole voltage commands to generate first pole voltage commands for switching of the first switching elements and second pole voltage commands for switching of the second switching elements.