Compensated Droop Method for Parallel Power Supply Load Regulation
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Solution Overview
Problem
The existing droop method for connecting multiple power supply modules in parallel often results in poor load regulation due to variations in output voltage and load current, which is not acceptable for many applications.
Innovation Solution
Incorporating a feedback control loop with a current sensor and compensation circuit that adjusts the reference signal based on the output current of each power supply module to maintain stable voltage and improve load regulation, using resistors and amplifiers to compensate for variations in output current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the droop method is used to connect multiple power supply modules in parallel, then the output current capability is increased, but the load regulation deteriorates due to variations in output voltage and load current
Solution Approach 1:
The patent implements a feedback control loop that monitors the output current of each power supply module and adjusts its output voltage accordingly. The feedback mechanism detects variations in output current and automatically compensates by modifying the output voltage to maintain equal current sharing among parallel modules, thereby resolving the load regulation deterioration caused by the traditional droop method
Solution Approach 2:
The patent dynamically changes the output voltage parameter of each power supply module based on real-time output current measurements. By adjusting the output voltage parameter in response to current variations, the system maintains optimal load regulation while preserving the increased current capability provided by parallel connection
2Power
If the droop method is used to connect multiple power supply modules in parallel, then the current capability is doubled, but the output voltage variation increases leading to poor load regulation
Solution Approach 1:
The feedback control loop continuously monitors output current and adjusts output voltage to compensate for variations. This closed-loop control mechanism detects voltage instability caused by current sharing variations and automatically corrects it, maintaining stable output voltage despite the increased current capability from parallel connection
Solution Approach 2:
The system takes preliminary action by proactively adjusting the output voltage before significant voltage instability occurs. The control mechanism anticipates voltage variations that would result from current sharing imbalances and pre-compensates by modifying the output voltage, thereby preventing rather than merely reacting to instability
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 enhances load regulation by ensuring that the output voltage remains stable even with increasing load current, improving the overall performance of parallel-connected power supply modules to within 0.1% tolerance.
Implementation Method 1
A first amplifier has first and second inputs coupled to first and second terminals of the first resistor
Implementation Method 2
A second amplifier has a first input coupled for receiving the output voltage of the power supply module, a second input coupled for receiving a first reference signal, and an output coupled for providing a feedback signal to the power conversion circuit
Data Source
AI summary
A power supply has multiple power supply modules connected in parallel. Each power supply module has a power conversion circuit having an input coupled for receiving an input voltage. A resistor is serially coupled in an output of the power conversion circuit. A current limit amplifier has first and second inputs coupled to first and second terminals of the first resistor. A feedback amplifier has a first input coupled for receiving an output voltage of the power supply module, a second input coupled for receiving a reference signal, and an output coupled for providing a feedback signal to the power conversion circuit. A compensation resistor is coupled between an output of the current limit amplifier and the second input of the feedback amplifier for adjusting the reference signal to compensate for variation in output current of the power conversion circuit.