Boost Converter Pulse Shaping for Electric Machine Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric machines, such as motors and generators, operate at varying efficiency levels due to changes in rotor speed and torque, leading to reduced overall efficiency when operating outside their 'sweet spot', which limits the range of battery-powered vehicles.
Innovation Solution
Implementing pulsed control with a power converter that includes a boost circuit to reduce rise and fall times of pulsed power, storing magnetic energy at the end of a pulse and using it at the beginning of the next pulse to improve efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the electric machine operates under varying load conditions, then the machine can adapt to different operating requirements, but the energy conversion efficiency decreases when operating outside the optimal 'sweet spot'
Solution Approach 1:
The patent applies periodic pulsed operation to the electric machine, switching between on and off states in a controlled cycle. This allows the machine to operate at peak efficiency during pulsed intervals while maintaining adaptability to varying load conditions through duty cycle modulation, resolving the contradiction between operating range and energy conversion efficiency.
2Device complexity
If conventional power converters are used without a boost circuit, then the device complexity is lower, but the rise and fall times of pulsed power are longer, reducing overall system efficiency
Solution Approach 1:
The boost circuit performs preliminary energy storage in its magnetic field during the off-state, preparing energy in advance for rapid delivery during the on-state. This preliminary action enables extremely fast rise and fall times without requiring complex switching arrangements, as the energy is pre-positioned for immediate transfer to the load.
Solution Approach 2:
The boost circuit acts as an intermediary energy storage element between the power supply and the electric machine. It mediates the power transfer by storing energy in its magnetic field during off-periods and releasing it during on-periods, enabling fast transient response while maintaining a relatively simple overall converter structure.
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
Enhances the efficiency of electric machines by operating them at or near their peak efficiency levels for a greater proportion of the drive cycle, reducing energy consumption and increasing the range of battery-powered vehicles.
Implementation Method 1
The boost circuit extracts at least some of a magnetic energy present in the electric machine at the end of a pulse to reduce the pulse fall time, stores at least some of the energy, and applies at least some of the energy at the beginning of a subsequent pulse to reduce the rise time
Data Source
AI summary
A boost circuit is arranged to reduce rise and fall times of pulsed power used for pulsed control operation of electric machines. Magnetic energy present in the electric machine at the end of a pulse is extracted by the boost circuit to reduce the pulse fall time. The energy is stored by the boost circuit and then applied at the beginning of a subsequent pulse to reduce the rise time. By reducing rise and fall times compared to not using such a boost circuit, machine efficiency is improved.