Active Phase Converter Topology for Balanced 480V Output
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Solution Overview
Problem
Existing solutions for converting single-phase AC power to three-phase AC power in areas lacking three-phase 480 VAC power are inefficient and costly, with high voltage unbalance and low efficiency in static and rotary converters, and high complexity and expense in inverters with high harmonic content.
Innovation Solution
A phase converter that uses first and second single-phase input terminals, storage capacitors, active half-bridge modules, and a controller to generate balanced three-phase AC power with a voltage doubling feature, effectively converting single-phase 240V AC to three-phase 480V AC without the need for full AC to DC conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If static and rotary converters are used to convert single-phase 240V to three-phase 480V, then voltage conversion is achieved, but voltage unbalance is high and efficiency is low
Solution Approach 1:
The patent replaces mechanical rotary converters with a solid-state electronic converter using semiconductor switches (IGBTs, MOSFETs, or BJTs) arranged in half-bridge modules. This substitution eliminates the mechanical components and voltage unbalance issues of rotary converters while achieving efficient single-phase to three-phase conversion with balanced output voltages through controlled switching operations.
Solution Approach 2:
The patent changes the operating parameters by using pulse-width modulation (PWM) techniques to control the switching of semiconductor devices. By varying the duty cycle and switching frequency, the converter achieves efficient power conversion while maintaining balanced three-phase output voltages, thereby improving both efficiency and voltage balance simultaneously.
2Adaptability or versatility
If inverters are used to convert single-phase AC to three-phase AC, then conversion capability is achieved, but device complexity and cost increase
Solution Approach 1:
The patent divides the converter into multiple independent half-bridge modules, each handling a specific phase conversion task. This segmentation allows for modular design and implementation, reducing overall system complexity while maintaining full conversion capability. Each module can be independently controlled and replaced, simplifying the overall system architecture.
Solution Approach 2:
The patent creates a universal converter design that can handle various load types (inductive, capacitive, resistive) and convert single-phase input to three-phase output without requiring separate circuits for each function. The half-bridge modules serve multiple purposes: voltage conversion, isolation, and waveform generation, thereby reducing overall device complexity while maintaining versatility.
3Productivity
If inverters with PWM output are used, then conversion is achieved, but output voltage contains high harmonic content limiting application
Solution Approach 1:
The patent introduces an intermediary LC filter network between the half-bridge modules and the three-phase output terminals. This filter acts as a mediator that removes high-frequency harmonic components from the PWM output while preserving the fundamental frequency components, thereby eliminating harmful harmonics and enabling broader application to sensitive loads without sacrificing conversion productivity.
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 phase converter achieves efficient conversion of single-phase AC to balanced three-phase AC with reduced voltage unbalance and increased efficiency, suitable for inductive, capacitive, and resistive loads, while minimizing complexity and cost.
Implementation Method 1
a storage capacitor or capacitors (21, 79)
Data Source
AI summary
A voltage doubling phase converter that converts single phase AC electric power to balanced three phase AC power. Two input terminals are connectable to a single-phase AC power source and connect directly to two output terminals of the converter. The phase converter has a storage capacitor, three active half-bridge modules connected to the storage capacitor, and a controller. Two modules connect to the input terminals and charge the storage capacitor. The other module connects to a third output terminal. The controller switches the module connected to the third output terminal and one of the other modules to generate and shape a second and a resultant third phase.