Boost Power Supply Circuit for Holdup Time With Smaller Capacitors
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Solution Overview
Problem
Conventional power supply circuits face challenges with large-sized inductors and capacitors, which limit power density and conversion efficiency, while maintaining sufficient holdup time of electrical energy.
Innovation Solution
A power supply circuit design incorporating a power factor correction (PFC) circuit with a first storage capacitor and a boost conversion circuit, utilizing smaller capacitors and transistors with higher switching speeds to transfer energy efficiently, reducing the size of components and increasing power density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If large-sized inductor L_pf and capacitor C_bk are used in conventional power supply circuits, then sufficient holdup time of electrical energy is maintained, but power density is limited and hardware cost increases
Solution Approach 1:
The power supply circuit is divided into two independent conversion paths: a first conversion circuit (PFC circuit) that converts AC input voltage to intermediate DC voltage, and a second conversion circuit (boost circuit) that converts intermediate DC voltage to output DC voltage. The energy storage function is segmented between capacitor C_bk in the first circuit and inductor L_bs in the second circuit, allowing each component to be optimized for its specific function rather than requiring oversized components to handle all functions.
Solution Approach 2:
The patent changes the operating parameters by introducing a second conversion circuit with different conversion ratio characteristics. The boost circuit operates with a conversion ratio greater than 1, allowing it to compensate for the lower energy storage capacity of smaller capacitors and inductors. This parameter change enables the use of smaller energy storage components while maintaining the required holdup time through coordinated operation of both circuits.
2Duration of action of stationary object
If large-sized inductor L_pf and capacitor C_bk are used in conventional power supply circuits, then sufficient holdup time of electrical energy is maintained, but hardware cost increases
Solution Approach 1:
The power supply circuit is divided into two independent conversion paths: a first conversion circuit (PFC circuit) that converts AC input voltage to intermediate DC voltage, and a second conversion circuit (boost circuit) that converts intermediate DC voltage to output DC voltage. The energy storage function is segmented between capacitor C_bk in the first circuit and inductor L_bs in the second circuit, allowing each component to be optimized for its specific function rather than requiring oversized components to handle all functions.
Solution Approach 2:
The patent changes the operating parameters by introducing a second conversion circuit with different conversion ratio characteristics. The boost circuit operates with a conversion ratio greater than 1, allowing it to compensate for the lower energy storage capacity of smaller capacitors and inductors. This parameter change enables the use of smaller energy storage components while maintaining the required holdup time through coordinated operation of both circuits.
3Productivity
If conventional boost conversion circuit is used, then power supply function is achieved, but conversion efficiency is limited due to diode voltage drop
Solution Approach 1:
Instead of using a diode for the rectification function in the second conversion circuit, the patent inverts the approach by using a transistor Q_bs with controlled conduction. This allows the current to flow during specific intervals when the transistor is turned on, avoiding the continuous voltage drop associated with diode forward conduction. The transistor can be fully enhanced, minimizing on-resistance and associated power losses.
Solution Approach 2:
The patent changes the operating parameters by introducing a second conversion circuit with different conversion ratio characteristics. The boost circuit operates with a conversion ratio greater than 1, allowing it to compensate for the lower energy storage capacity of smaller capacitors and inductors. This parameter change enables the use of smaller energy storage components while maintaining the required holdup time through coordinated operation of both circuits.
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 design achieves reduced hardware costs and increased power density without compromising holdup time by using smaller capacitors and transistors with higher switching speeds to manage voltage ripples effectively.
Implementation Method 1
a first storage capacitor... The first storage capacitor is used to store a first electrical energy related to the intermediate voltage
Implementation Method 2
The second storage capacitor is connected to the first post-stage diode and is used to store the second electrical energy related to the output voltage
Implementation Method 3
The PFC circuit... includes a first front-stage inductor... The boost conversion circuit includes a first post-stage inductor... The first electrical energy is completely or partially transferred as the second electrical energy
Data Source
AI summary
A power supply circuit includes a power factor correction (PFC) circuit used to perform a power factor correction to generate an intermediate voltage. A first storage capacitor is used to store a first electrical energy related to the intermediate voltage. A boost conversion circuit is connected to the PFC circuit and used to generate an output voltage according to the intermediate voltage. The boost conversion circuit includes a first post-stage inductor, a first post-stage diode and a first post-stage transistor. A second storage capacitor is used to store a second electrical energy related to the output voltage. The capacitance value of the second storage capacitor is less than the capacitance value of the first storage capacitor; the first electrical energy is completely or partially transferred as the second electrical energy.