AC-DC Converter Drive Power via Transformer Secondary
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Solution Overview
Problem
Conventional AC-DC converter devices require separate isolated converters, leading to increased complexity and component count due to the need for non-isolated direct-current power supply when the alternating-current terminal of the S phase is at its lowest potential.
Innovation Solution
An AC-DC converter device utilizing a transformer with series-connected primary and secondary windings, bidirectional switches formed by semiconductor switching elements like GaN HEMTs, and drive circuit power supply generating circuits that produce direct-current positive and negative voltages from alternating-current power, allowing on-off switching without separate isolated converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate isolated converters are used to provide drive circuit power supply, then reliable power supply is ensured, but device complexity increases
Solution Approach 1:
The patent merges the drive circuit power supply function into the main AC-DC converter circuit by using the transformer's secondary winding to directly generate the drive voltages. The bidirectional switches and capacitors in the main circuit are utilized to generate positive and negative drive voltages without requiring separate isolated converters, thus reducing device complexity while maintaining power supply reliability through the transformer's isolation capability.
2Stability of the object's composition
If separate isolated converters are used, then power supply stability is maintained, but component count increases
Solution Approach 1:
The patent makes the transformer serve multiple functions: it provides both the main power conversion and the drive circuit power supply. The secondary winding generates both positive and negative drive voltages for the bidirectional switches, making the transformer a universal component that eliminates the need for separate isolated converters and reduces the overall component count while maintaining power supply stability.
Solution Approach 2:
The main converter circuit generates its own drive power supply through the transformer's secondary winding and the bidirectional switch configuration. The capacitors connected to the secondary winding automatically generate the required positive and negative voltages during the switching operation, allowing the circuit to be self-sufficient without external isolated converters.
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
Enables direct-current power supply using non-isolated simple circuits, reducing component complexity and maintaining efficient operation by setting the reference potential points to the midpoint of the alternating-current power supply voltage.
Implementation Method 1
a series circuit including a first primary winding 9a1 of the transformer 9, a bidirectional switch Q1, and a second primary winding 9a2 of the transformer 9 which are connected one to another in series in this order
Data Source
AI summary
In the present invention, switching circuits connected in middle points of power supply lines of a three-phase alternating-current power supply are switched to cause currents to intermittently flow on primary windings of a transformer, a voltage generated on a secondary winding is rectified and smoothed, and then is outputted to a load. The switching circuits each include: a series circuit including a first primary winding, a bidirectional switch and a second primary winding, which are connected in series in this order; a drive circuit power supply generating circuit generating a direct-current positive voltage and a direct-current negative voltage by use of an alternating-current power supply voltage applied between two ends of the series circuit; and a drive circuit performing on-off drive of the bidirectional switch. A reference potential point of the bidirectional switch is connected to a reference potential point of the drive circuit power supply generating circuit.