DC Power Supply Reactor Control for Diode Current Reduction
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Solution Overview
Problem
Conventional direct-current power supply devices face issues with high switching losses and increased diode current capacity when outputting voltages higher than double voltage rectification, leading to inefficiencies and higher costs due to the need for diodes with large current capacity.
Innovation Solution
A direct-current power supply device incorporating a reactor, switching unit, rectifying unit, smoothing capacitor, and control unit that controls the switching unit to stop alternating-current voltage supply after a predetermined time from the zero cross point, reducing inrush current and allowing the use of diodes with smaller current capacity and lower loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If voltage three times as high as alternating-current power supply voltage is generated, then high voltage output is achieved, but a large inrush current flows to the diode and current capacity of the diode increases
Solution Approach 1:
The reactor is pre-charged through the switching unit before the rectifying unit operates, storing energy in the magnetic field. This preliminary action prevents inrush current by gradually building up the voltage rather than allowing sudden charging of the output capacitor, thus protecting the diode from excessive current while achieving high voltage output
2Power
If full wave rectification and double voltage rectification are switched with boosting control, then voltage equal to or higher than double voltage rectification is output, but switching loss increases
Solution Approach 1:
The switching unit operates periodically to charge the reactor during specific intervals, creating a rhythmic charging-discharging cycle. This periodic action allows the system to achieve voltage boosting through the reactor's energy storage and release, eliminating the need for continuous switching control and reducing switching losses while maintaining high voltage output
3Power
If voltage about twice to four times as high as peak voltage is output by controlling voltage ratio, then high voltage output is achieved, but peak of electric current flowing to diode increases
Solution Approach 1:
The reactor serves as an intermediary energy storage element between the alternating-current power supply and the rectifying unit. It mediates the energy transfer by storing energy in its magnetic field during charging phases and releasing it during discharging phases, thereby smoothing current flow and preventing peak currents from reaching the diode while enabling high voltage output through controlled energy release
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 configuration enables efficient and cost-effective output of direct-current voltage twice to three times the peak value of the alternating-current voltage with reduced losses and lower diode costs.
Implementation Method 1
a reactor, one end of which is connected to one output end of an alternating-current power supply; a switching unit for short-circuiting the other end of the reactor and the other output end of the alternating-current power supply
Implementation Method 2
a rectifying unit configured to rectify an alternating-current voltage supplied from the alternating-current power supply and generate a voltage equal to or higher than a double voltage
Implementation Method 3
a smoothing capacitor connected to the rectifying unit via backflow preventing diodes and configured to smooth a direct-current voltage output from the rectifying unit
Data Source
AI summary
A direct-current power supply device includes a reactor, one end of which is connected to one output end of an alternating-current power supply, a switching unit for short-circuiting the other end of the reactor and the other output end of the alternating-current power supply, a rectifying unit configured to rectify an alternating-current voltage supplied from the alternating-current power supply and generate a voltage equal to or higher than a double voltage, a smoothing capacitor connected to the rectifying unit via backflow preventing diodes and configured to smooth a direct-current voltage output from the rectifying unit, and a control unit configured to control the switching unit and stop the supply of the alternating-current voltage to the rectifying unit in a predetermined period after a predetermined time has elapsed from a zero cross point of the alternating-current voltage output from the alternating-current power supply.