Bridgeless Three-Phase Wind Power Charging Circuit
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Solution Overview
Problem
Conventional wind turbine systems face inefficiencies in power conversion due to three-phase PFC units, particularly under low voltage and high current operations, and are characterized by high assembly costs and input current distortion, which are not adequately addressed by existing solutions.
Innovation Solution
A novel wind power charging circuit with a three-phase, single-stage and bridgeless framework utilizing an isolated single-ended primary-inductance converter (SEPIC) with buck-boost functionality, incorporating EMI filtering units, energy storing units, power switching units, and a Y-Δ transformer to enhance voltage range and efficiency, while eliminating bridge-type diode rectifiers and PFC circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a three-phase PFC unit with EMI filter or diode rectifier is used, then the power factor is improved, but the input efficiency deteriorates under low voltage and high current operation
Solution Approach 1:
The patent extracts and eliminates the three-phase PFC unit and bridge-type diode rectifier from the conventional two-stage circuit, retaining only the essential power conversion function. This removal of unnecessary components directly addresses the low efficiency under low voltage/high current conditions while maintaining adequate power factor through the simplified single-stage architecture.
Solution Approach 2:
The patent merges the power factor correction function and power conversion function into a single integrated stage, eliminating the need for separate PFC unit and rectifier. This consolidation reduces component count and improves efficiency by removing intermediate conversion losses while maintaining overall system performance.
2Object-generated harmful factors
If a bridgeless PFC unit is used to solve input current distortion, then the current distortion is reduced, but the framework size and assembly cost increase due to two-stage circuit structure
Solution Approach 1:
The patent extracts and removes the bridgeless PFC unit from the circuit, eliminating the need for complex two-stage architecture. The simplified single-stage design inherently produces less input current distortion while significantly reducing framework size and assembly cost by eliminating redundant components.
Solution Approach 2:
The patent combines power conversion and rectification into a single integrated stage, eliminating the need for separate PFC stage. This merger reduces the overall device complexity, framework size, and assembly cost while maintaining acceptable current quality through proper component selection and circuit topology.
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 solution enables wide-range operation under varying wind speeds, reduces conducting losses and assembly costs, and enhances electromechanical conversion efficiency, maintaining a steady output voltage and minimizing circuit volume.
Implementation Method 1
a first filtering inductor and a second filtering inductor induced respectively by an R-phase winding and an S-phase winding of three phase windings of the wind turbine
Implementation Method 2
a three-phase transformer, coupled to the first energy storing unit, the second energy storing unit and the third energy storing unit, and used for receiving the first primary side voltage, the second primary side voltage and the third primary side voltage and then outputting a first secondary side voltage, a second secondary side voltage and a third secondary side voltage
Data Source
AI summary
The present invention provides a novel wind power charging circuit with three-phase, single-stage and bridgeless framework. This novel wind power charging circuit is developed based on an isolated single-ended primary-inductance converter (SEPIC) having buck-boost converting function, and can be applied in a wind turbine system for increasing the operation scope of the input voltage provided by a wind turbine of the wind turbine system, so as to facilitate the wind turbine system include wide-range operation scope under different wind speeds, such that the electric energy production and the electromechanical conversion efficiency of the wind turbine system are able to be effectively enhanced. In addition, because this novel wind power charging circuit does not include any bridgeless PFC circuits and bridge-type diode rectifiers, the low conducting loss as well as the whole circuit volume and assembly cost of the wind turbine system can be simultaneously reduced.