Capacitorless DC Machine Using Center-Tapped Commutation Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of large energy storage capacitors in DC electrical machines limits operational reliability and design flexibility, especially in high power applications, due to increased failure rates at high temperatures and reduced space for design, affecting efficiency and flexibility.
Innovation Solution
The implementation of multiple commutation cells connected in series, which operate as the stator of the DC electrical machine, eliminating or reducing the need for energy storage capacitors by using anti-parallel switching units and center-tapped or separate coils to control electrical power flow based on induced voltages, allowing the machine to operate in both motor and generator modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If large energy storage capacitors are used in DC electrical machines, then the machine can operate in high power applications, but operational reliability decreases and design flexibility is limited
Solution Approach 1:
The patent extracts and eliminates the energy storage capacitor from the DC electrical machine system. By using a bridge circuit with switching devices controlled by a controller, the system achieves capacitorless operation while maintaining high power capability. This removal of the capacitor directly improves reliability by eliminating a component known to have high failure rates at elevated temperatures.
2Power
If large energy storage capacitors are used in DC electrical machines, then the machine can handle high power applications, but design flexibility is reduced
Solution Approach 1:
By extracting the capacitor from the system and replacing it with a bridge circuit configuration, the patent enables greater design flexibility. The controller can dynamically adjust switching device operation to accommodate various operating conditions and application requirements, making the machine more adaptable without being constrained by capacitor size and placement limitations.
3Power
If large energy storage capacitors are used in DC electrical machines, then high power operation is enabled, but space for design is reduced
Solution Approach 1:
The patent removes the large energy storage capacitor from the machine structure, thereby freeing up significant space within the stationary object. The bridge circuit and switching devices occupy considerably less space than traditional large capacitors, allowing for more compact designs and better utilization of available space in high power applications.
4Power
If traditional DC electrical machines use large energy storage capacitors, then high power conversion is achieved, but operational efficiency decreases
Solution Approach 1:
The patent replaces the passive energy storage capacitor system with an active electronic control system using switching devices and a controller. This substitution enables more efficient power conversion by dynamically controlling current flow through the bridge circuit, reducing energy losses and improving overall operational efficiency while maintaining high power conversion capability.
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 enhances operational efficiency and design flexibility by eliminating capacitors, improving reliability and space utilization, particularly in high voltage and high speed applications, while simplifying construction and eliminating the need for mechanical commutators.
Implementation Method 1
a rotor configured to generate a rotor magnetic field
Implementation Method 2
the electrical power may produce a magnetic field that causes actuation of a rotor in the electrical machine, thereby converting electrical energy into mechanical energy
Data Source
Figure 1~2
Figure 3
Figure 4~6B
AI summary
A direct current electrical machine, which includes a rotor that generates a rotor magnetic field, a first commutation cell (36) that includes a winding component (44), a first switching device (42A), and a second switching device (42B). The first winding component includes a first portion electrically coupled between a first terminal and a second terminal of the first winding component (44) and a second portion electrically coupled between a third terminal and the second terminal of the first winding component (44). The first switching device (42A) is electrically coupled to the first terminal and is closed when a first voltage induced across the first portion by rotation of the rotor magnetic field is positive; and the second switching device (42B) is electrically coupled to the third terminal and is closed when a second voltage induced across the second portion by the rotation of the rotor magnetic field is negative.