Current Balanced Push-Pull Inverter Circuit with Snubber Regeneration
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Solution Overview
Problem
Existing inverter circuits, such as full bridge, half bridge, and center tap push pull types, face issues with high costs, excessive current flow, and inefficiencies due to leakage inductance, leading to high surge voltages and reduced efficiency.
Innovation Solution
A current balanced push pull inverter circuit using two semiconductor switching elements with a primary winding connected between them, along with a snubber and regeneration circuit for Zero Voltage Switching (ZVS) operation, reducing current flow and surge voltages, and enhancing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a full bridge type inverter circuit is used, then the circuit can operate with standard switching elements, but the cost becomes high since four switching elements are used
Solution Approach 1:
The patent divides the primary winding into two separate windings (first primary winding and second primary winding) connected in series. This segmentation allows the use of only two switching elements instead of four, as each switching element controls one half of the primary winding, thereby reducing component count while maintaining full-bridge functionality
Solution Approach 2:
Instead of using four switching elements in a conventional full-bridge configuration, the patent inverts the approach by using two switching elements with the primary winding segmented into two series-connected windings. This inversion of the traditional topology achieves the same voltage transformation function with fewer components
2Device complexity
If a half bridge type inverter circuit is used, then only two switching elements are needed, but the currents flowing in the switching elements and primary winding are twice as great
Solution Approach 1:
The primary winding is segmented into two series-connected windings (first and second primary windings). This segmentation divides the current path such that each switching element carries only the transformed current, not doubled current, thereby reducing current magnitude while maintaining the two-switch configuration
Solution Approach 2:
The patent introduces a temporal dimension to the circuit operation by alternately switching the two switching elements in a push-pull manner. This time-based switching strategy allows the current to flow through different paths at different times, effectively reducing the instantaneous current burden on each component
3Quantity of substance
If a center tap push pull type inverter circuit is used, then two switching elements suffice with reduced current, but leakage inductance causes excessive surge voltage on switching elements
Solution Approach 1:
The patent removes the center tap connection from the primary winding, eliminating the source of leakage inductance that causes surge voltage. By extracting this problematic element and using separate series-connected windings instead, the circuit achieves both low current operation and reduced surge voltage
Solution Approach 2:
The patent introduces an intermediary mechanism in the form of snubber circuits connected across each switching element. These snubber circuits act as mediators that absorb and dissipate the surge voltage energy, protecting the switching elements from excessive voltage spikes while allowing the push-pull operation to continue
4Object-affected harmful factors
If a CR snubber circuit is used to protect switching elements, then surge voltage is reduced, but efficiency becomes bad since charge is consumed as heat
Solution Approach 1:
The patent modifies the snubber circuit to recover the energy stored in the snubber capacitor rather than dissipating it as heat. The recovered energy is fed back to the primary side circuit, transforming the snubber from an energy-consuming component to an energy-recycling component, thereby improving overall circuit efficiency
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 allows for low current flow and reduced surge voltages in switching elements, achieving high efficiency through ZVS operation and regeneration of snubber capacitor charge, thereby minimizing losses.
Implementation Method 1
since the power supply V is connected to the center tap upon the primary winding P, accordingly a leakage inductance is interposed into the combination of the left and right sides of the winding P
Implementation Method 2
via the above described leakage inductance, the surge voltage that is generated when the first switching element is turned OFF
Implementation Method 3
with a snubber and regeneration circuit for Zero Voltage Switching (ZVS) operation, reducing current flow and surge voltages, and enhancing efficiency
Implementation Method 4
regeneration of snubber capacitor charge, thereby minimizing losses
Implementation Method 5
an output transformer, which is provided with a first primary winding P1 which is connected in series between said first switching element S1 and said second switching element S2, and also with a secondary winding for obtaining an output voltage
Data Source
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AI summary
This inverter circuit includes two switching elements which are turned alternately ON and OFF, and a first primary winding connected in series between these switching elements, and also includes an output transformer having a secondary winding for obtaining an output voltage. This inverter circuit also includes a first voltage source and a second voltage source. The first voltage source applies a voltage to the first switching element via the first primary winding. And the second voltage source applies a voltage to the second switching element via the second primary winding. This inverter circuit also includes a regeneration snubber circuit for regenerating charge accumulated in a snubber capacitor. The regeneration snubber circuit includes a regeneration circuit including a voltage boost section which converts the primary side voltage of the output transformer to a predetermined voltage, which it outputs.