Open-End Winding Motor Drive Control for Common Mode Current Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In motor drive systems using the open-end winding method, the inability to control zero phase component voltages leads to common mode currents, causing losses and potential burnout due to copper and iron losses, which deteriorate efficiency and accelerate damage to the motor system.
Innovation Solution
A motor drive device is designed with two inverters connected to opposite ends of the motor windings, where a controller generates phase voltage commands for both inverters to ensure they have the same zero phase component voltage, eliminating the voltage difference and thereby suppressing circulating currents. This is achieved by using specific multiplication factors and coordinate conversions to align the phase voltage commands of the inverters, ensuring they have the same magnitude and a 120-degree angle difference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the open-end winding method is used with two inverters connected to opposite ends of motor windings, then the voltage utilization rate is enhanced and high power is output, but common mode current is generated causing copper loss and iron loss
Solution Approach 1:
The patent changes the control parameters of the two inverters by introducing different phase angles (θ1 and θ2) in the voltage command generation. By adjusting these phase angle parameters, the zero-phase component voltages are made equal, which eliminates the common mode current and reduces copper loss and iron loss while maintaining high output power capability.
2Use of energy by moving object
If the open-end winding method is used with two inverters, then the voltage utilization rate is enhanced, but zero phase component voltage difference causes circulating currents
Solution Approach 1:
The patent modifies the voltage command parameters by introducing phase angle adjustments (θ1 and θ2) to ensure that the zero-phase component voltages of both inverters are equal. This parameter change eliminates the voltage difference that causes circulating currents, while preserving the enhanced voltage utilization rate benefit of the open-end winding configuration.
3Ease of operation
If general DC power is applied to the inverters in open-end winding method, then the motor can be driven, but zero phase component voltage cannot be controlled to become zero, generating common mode current
Solution Approach 1:
The patent enhances the control parameters by introducing phase angle adjustments (θ1 and θ2) in the voltage command generation equations. This allows the zero-phase component voltages to be controlled and made equal, thereby eliminating common mode current and improving motor system reliability while maintaining ease of operation.
Data Source
AI summary
A motor drive device is proposed. The motor drive device is configured to drive a motor having a plurality of windings respectively corresponding to a plurality of phases, and includes: a first inverter including a plurality of first switching elements, and connected to a first end of each of the plurality of windings; a second inverter including a plurality of second switching elements, and connected to a second end of each of the plurality of windings; and a controller configured to generate phase voltage commands of the first inverter and phase voltage commands of the second inverter based on preset voltage commands of the motor so that the phase voltage commands of the first inverter and the phase voltage commands of the second inverter are respectively represented as vectors of different angles.