Power Supply Apparatus Dynamic Frequency Control
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Solution Overview
Problem
Conventional power supply apparatuses suffer from reduced efficiency due to switching losses in switching elements and reverse recovery losses in diodes during on-off cycles.
Innovation Solution
The power supply apparatus operates in two modes: a high-frequency mode for high load currents and a low-frequency mode for low load currents, where the converter outputs voltage is stepped up or down by a bidirectional chopper to optimize efficiency by minimizing losses in switching elements and diodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If switching elements are turned on and off frequently to meet load demands, then the power supply can respond to varying load conditions, but switching losses and reverse recovery losses increase, reducing overall efficiency
Solution Approach 1:
The patent implements dynamic switching frequency adjustment based on load conditions. The control unit monitors the load current and dynamically switches between two operating modes: a first switching frequency for high load currents and a second, lower switching frequency for low load currents. This dynamic adaptation allows the power supply to maintain high efficiency across varying load conditions while still responding appropriately to demand changes
Solution Approach 2:
The patent changes the switching frequency parameter based on load conditions. By detecting whether the load current exceeds a threshold value, the control unit adjusts the switching frequency between two discrete values. This parameter change optimizes the balance between response capability and efficiency, reducing switching and reverse recovery losses during light load operation while maintaining adequate response during heavy load operation
2Quantity of substance
If the converter output voltage is stepped down by the bidirectional chopper, then power storage apparatus can be charged, but additional switching losses occur in the chopper
Solution Approach 1:
The bidirectional chopper operates in periodic cycles, alternating between connecting the converter output to the power storage apparatus for charging and connecting to the output terminal for power delivery. This periodic action allows the system to accumulate energy in the power storage apparatus when available and deliver it when needed, optimizing the overall energy management while managing the inherent switching losses through proper timing and control
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 reduces overall losses, enhancing the efficiency of the power supply apparatus by adjusting switching frequencies based on load conditions, thereby improving energy utilization.
Implementation Method 1
The converter (6) converts AC power to DC power and outputs the DC power to a first node
Implementation Method 2
the bidirectional chopper (11) is configured to during the first operation mode, step down a DC voltage of the output terminal and output the DC voltage to a second node, and during the second operation mode, step up the DC voltage of the second node and output the DC voltage to the output terminal
Data Source
AI summary
An uninterruptible power supply apparatus (1) drives a converter (6) at a relatively high frequency (fH) and supplies an output voltage (VDC) of the converter (6) directly to a load (23) when a load current (IL) is greater than a predetermined value (Ic), and drives the converter (6) at a relatively low frequency (fL), steps up the output voltage (VDC) of the converter (6) by a bidirectional chopper (11), and supplies the output voltage (VDC) of the converter (6) to the load (23) when the load current (IL) is smaller than the predetermined value (Ic).