Power Converter Phase Transition Current Continuity
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Solution Overview
Problem
Existing power converters suffer from discontinuous phase transition current and high total harmonic distortion (THD) in output alternating-current power.
Innovation Solution
A power converter design incorporating a controller that generates control signals by comparing a mixed sine wave with a high-frequency triangular carrier, using a third-order harmonic of a low-frequency sine wave, and employing half-bridge circuits with switches connected in series to maintain continuous output current and reduce THD, with additional components like capacitors and inductors forming filter circuits to enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional control means are used in power converters, then the device complexity is reduced, but discontinuous phase transition current and high total harmonic distortion occur in the output AC power
Solution Approach 1:
The patent applies parameter changes by mixing a third-order harmonic into the sine wave control signal. This modifies the control signal parameters (adding harmonic content) to achieve continuous phase transition current and reduce THD, resolving the contradiction between reliability and complexity by optimizing the control signal characteristics rather than adding hardware complexity
Solution Approach 2:
The patent introduces an intermediary mixing circuit that combines the fundamental sine wave with its third-order harmonic. This intermediary process generates an enhanced control signal that ensures continuous current flow during phase transitions while maintaining manageable device complexity through signal processing rather than hardware multiplication
2Reliability
If conventional control means are used in power converters, then the device complexity is reduced, but total harmonic distortion in the output AC power increases
Solution Approach 1:
The patent changes the control signal parameters by incorporating the third-order harmonic of the sine wave. This parameter modification improves output power quality by reducing THD and eliminating discontinuous current, while avoiding excessive complexity through analytical signal synthesis rather than complex control algorithms or additional hardware
3Reliability
If mixed sine wave with third-order harmonic is used for control signal generation, then phase transition current continuity is achieved, but the manufacturing precision requirements increase
Solution Approach 1:
The mixing circuit generates the third-order harmonic from the same sine wave source used for control, making the system self-sufficient. The harmonic is derived analytically from the fundamental frequency, eliminating the need for external precision components and reducing manufacturing precision requirements while maintaining reliable continuous phase transition current
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 solution ensures continuous phase transition stability and reduces total harmonic distortion in output AC power, improving the overall efficiency and quality of the power conversion process.
Implementation Method 1
the control signal provided for the second half-bridge circuit or the third half-bridge circuit by the controller is generated by comparing a mixed sine wave with a high-frequency triangular carrier
Implementation Method 2
a third inductor connected to the AC power output line and connected to the node between the third switch and the fourth switch, and a third capacitor connected to a node between the AC power output line and the neutral line, wherein the third inductor and the third capacitor together form a filter circuit
Data Source
AI summary
A power converter includes an AC power input line, an AC power output line, a neutral line, a first capacitor connected to the AC power input line and the neutral line, a first inductor connected to the AC power input line, a first bus, a second bus, a second capacitor connected to the first bus and the second bus, a first half-bridge circuit connected to the first bus, the second bus and the first inductor, a second half-bridge circuit connected in series with the first half-bridge circuit and connected to the AC power output line, a third half-bridge circuit connected in series with the first half-bridge circuit, a second inductor connected to the third half-bridge circuit and the neutral line, and a controller.