Two-Phase Motor Assembly With Asymmetrical Windings for High-Speed Torque
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Solution Overview
Problem
Existing single-phase motors face limitations in starting capability, voltage imbalance, and difficulty in high-speed operation, leading to inefficiencies and reduced lifespan of capacitors, especially in applications requiring high torque and low frequency.
Innovation Solution
A two-phase motor assembly with an optimized inverter structure and high-speed driving scheme, featuring asymmetrical current application and a 90-degree phase difference between windings, along with a controller for torque distribution, enables high-speed operation and reduces motor weight and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-phase motor is used to reduce device complexity, then the starting capability is limited and voltage imbalance occurs, but adding starting capacitors and neutral points increases device complexity
Solution Approach 1:
The single-phase motor is segmented into two independent windings (first winding and second winding) with different resistance values, allowing each winding to carry different currents. This segmentation enables the motor to achieve better starting capability and voltage balance without requiring additional starting capacitors or neutral points, thus resolving the contradiction between device complexity and reliability
Solution Approach 2:
The patent applies asymmetry by designing the first winding and second winding with intentionally different resistance values. This asymmetric design allows the windings to draw different currents, creating a phase difference that generates effective starting torque and improves voltage utilization, thereby enhancing starting capability without increasing device complexity
2Speed
If a single-phase motor is used to simplify the system, then the maximum speed is limited, but increasing motor design capacity occupies more volume
Solution Approach 1:
The patent changes key parameters including winding resistances, current distributions, and voltage utilization strategies to enable high-speed operation in a single-phase motor. By optimizing these parameters, the motor achieves maximum speeds comparable to three-phase motors without increasing volume, as the improved voltage utilization allows better performance from the existing motor design capacity
3Power
If asymmetrical current is applied to increase voltage utilization, then the output increases, but the torque control becomes more complex
Solution Approach 1:
The controller implements feedback mechanisms to monitor and adjust the asymmetrical current distribution between the two windings. By using feedback control, the system maintains optimal torque production and voltage utilization while managing the complexity of asymmetrical current application, ensuring stable motor operation across different load conditions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The two-phase motor assembly achieves high-speed operation, increased output, and miniaturization, improving suction power in vacuum cleaners while maintaining voltage utilization comparable to three-phase motors, with enhanced torque control and reduced torque ripple.
Implementation Method 1
an inverter for driving the motor
Implementation Method 2
a first winding and a second winding that have an electrically insulated parallel structure
Data Source
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AI summary
The present disclosure relates to a motor assembly, and more particularly, to a motor having a two-phase input power source and a power conversion device for driving a two-phase motor. The present disclosure relates to the motor assembly for driving the two-phase motor, the motor assembly configured to comprise: a motor including a first winding and a second winding having an electrically insulated parallel structure; a DC-link circuit for supplying a direct-current voltage; and an inverter connected to the DC-link circuit to convert the direct-current voltage into an alternating-current voltage to drive the motor, and including a first switching element set connected to the first winding and a second switching element set connected to the second winding.