Isolated Power Supply Frequency Modulation Control
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Solution Overview
Problem
Conventional isolated switching mode power supplies face high power consumption due to the constant operation of opto-couplers, especially under light loads, which reduces efficiency.
Innovation Solution
The implementation of a frequency modulation-based control system that uses a secondary controller to generate a frequency control signal from the output voltage and current sense signals, allowing the primary controller to adjust the primary power switch's operation, thereby reducing the power consumption by minimizing the idle time of the opto-coupler and auxiliary circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the opto-coupler and auxiliary circuits operate continuously to maintain proper power supply work, then the reliability is improved, but the power consumption increases significantly under light load conditions
Solution Approach 1:
The patent applies periodic action by controlling the opto-coupler and auxiliary circuits to operate only during necessary periods rather than continuously. The control circuit activates these components based on load conditions and switching cycles, allowing them to remain idle during light load or no-load conditions, thereby reducing power consumption while maintaining reliability when needed.
Solution Approach 2:
The patent implements dynamics by making the operation state of the opto-coupler and auxiliary circuits adaptive rather than static. The control circuit dynamically adjusts their activation based on real-time load conditions, enabling the system to transition between active and idle states, thus optimizing the balance between reliability and power consumption under varying operational conditions.
2Stability of the object's composition
If the opto-coupler and resistor operate constantly to provide feedback, then the stability is improved, but the efficiency deteriorates under light or no-load conditions
Solution Approach 1:
The control circuit implements periodic action by activating the opto-coupler and auxiliary circuits only during specific switching cycles when feedback is actually needed, rather than maintaining continuous operation. This periodic activation maintains feedback stability when required while minimizing energy loss during light load or no-load conditions where full feedback operation is unnecessary.
Solution Approach 2:
The patent applies the extraction principle by selectively removing the operation of the opto-coupler and auxiliary circuits from continuous operation. The control circuit extracts these components from the always-on state and activates them only when needed based on load conditions, thereby eliminating unnecessary energy consumption while preserving feedback stability during actual operation.
3Measurement precision
If the primary side control system operates continuously to regulate output voltage, then the control precision is improved, but the power consumption increases under light load conditions
Solution Approach 1:
The control circuit implements dynamics by adaptively adjusting the operation of the primary side control system based on load conditions. Under light load or no-load conditions, the control circuit reduces or suspends continuous regulation operations, allowing the system to maintain control precision when needed while minimizing power consumption during periods when full regulation is less critical.
Solution Approach 2:
The patent applies periodic action by organizing the primary side control operations into discrete switching cycles rather than continuous operation. The control circuit activates regulation functions during specific cycles when output voltage control is necessary and allows idle periods during light load conditions, thereby maintaining control precision while reducing overall power consumption.
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 approach significantly reduces power consumption and improves efficiency by adapting energy transfer based on load changes, particularly under light or no-load conditions, thereby enhancing the overall performance of the isolated switching mode power supply.
Implementation Method 1
a transformer T1 comprising a primary winding Lp, a secondary winding Ls and a third winding Lt is applied as energy storage element in the power supply 10
Data Source
AI summary
An isolated switching mode power supply, having: an input terminal; an output terminal; a transformer having a primary winding and a secondary winding; a primary power switch coupled to the primary winding; a secondary power switch coupled between the secondary winding and the output terminal of the power supply; a secondary controller configured to generate a frequency modulation signal based on the output voltage and the first feedback signal; a coupled device configured to provide a frequency control signal based on the output voltage and the frequency modulation signal; and a primary controller configured to provide a switching signal to control the primary power switch based on the current sense signal and the frequency control signal.