Flux Regulated PM Generator for AC Motor Drive
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Solution Overview
Problem
Motor drive systems for AC motors require high power electronics to convert variable frequency AC power, leading to increased size, weight, and cost, particularly in mobile applications where size and weight minimization is crucial.
Innovation Solution
The use of controlled permanent magnet machines with a magnetic flux diverter circuit to generate and control high frequency alternating current power, transforming it into variable low frequency AC motor control output, allowing for low power electronics to manage the necessary frequency range for AC motor operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If high power electronics are used to convert variable frequency AC power, then the frequency conversion capability is improved, but the size and weight of the system increase
Solution Approach 1:
The patent changes the operating parameters of the permanent magnet generator by controlling the magnetic flux diverter circuit to operate at high frequency (e.g., 400 Hz or higher) rather than traditional low frequencies. This parameter change enables the generator to produce variable frequency output directly, eliminating the need for heavy power electronic converters while maintaining frequency conversion capability.
Solution Approach 2:
The patent extracts and removes the high power electronics conversion stage from the system by implementing frequency control directly at the generator level through the magnetic flux diverter circuit. This extraction eliminates the bulky power electronic equipment while retaining the essential frequency conversion function.
2Adaptability or versatility
If high power electronics are used to convert variable frequency AC power, then the frequency conversion capability is improved, but the cost of the system increases
Solution Approach 1:
The patent removes the expensive high power electronics conversion equipment from the system by implementing frequency control directly in the generator through the magnetic flux diverter circuit. This extraction eliminates the need for costly power electronic components and their associated cooling, control, and protection systems.
Solution Approach 2:
By changing the generator's operating frequency parameter to high frequency and using the magnetic flux diverter for direct control, the system avoids the need for expensive power electronic frequency converters, thereby reducing overall system cost while maintaining frequency conversion capability.
3Weight of stationary object
If a permanent magnet generator with magnetic flux diverter circuit is used, then the size and weight of power electronics are reduced, but the complexity of magnetic flux control increases
Solution Approach 1:
The patent introduces a magnetic flux diverter circuit as an intermediary component between the generator's magnetic field and the stator windings. This diverter circuit, controlled by a relatively simple control signal, modulates the magnetic flux to achieve frequency conversion without requiring complex power electronic equipment. The control complexity is concentrated in a small, lightweight control circuit rather than heavy power electronics.
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
This approach reduces the size and weight of motor drive systems by enabling efficient control of AC motor speeds with lower power electronics, thereby minimizing system size and cost while maintaining performance.
Implementation Method 1
rotating the PM rotor at a velocity sufficient to develop a high frequency alternating current (HFAC) power output from the stator
Implementation Method 2
magnetic flux diverter circuit for controlling the output of the PMM
Data Source
AI summary
A method of generating and controlling power for an alternating current (AC) motor by means of at least one controlled permanent magnet machine (PMM) with a permanent magnet (PM) rotor and a stator with a magnetic flux diverter circuit for controlling the output of the PMM, comprises the steps of: rotating the PM rotor at a velocity sufficient to develop a high frequency alternating current (HFAC) power output from the stator; transforming the HFAC output to produce a variable low frequency alternating current (AC) motor control output for the motor; sensing desired motor control parameters; generating a control signal responsive to the sensed parameters; and applying the control signal to the magnetic flux diverter circuit to control the motor control output.