Auxiliary Power Supply Circuit Using Switch-Node Energy Recovery
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Solution Overview
Problem
Existing auxiliary power supply circuits face inefficiencies in power utilization and stability, particularly in gate-drive power supply circuits, leading to high power consumption and potential overvoltage issues.
Innovation Solution
The proposed auxiliary power supply circuit incorporates a high-withstand-voltage and low-withstand-voltage transistor series connection, rectification element, and auxiliary power supply capacitor, along with a Zener diode and smoothing capacitor, to manage voltage and current surges, ensuring stable power delivery to the gate drive capacitor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional auxiliary power supply circuit is used, then the circuit can provide power supply function, but the power utilization efficiency is low and power consumption is high
Solution Approach 1:
The auxiliary power supply circuit uses itself to generate the power it needs for operation. The rectification element rectifies the voltage at the connection node between the high-withstand-voltage and low-withstand-voltage transistors, and the auxiliary power supply capacitor stores this rectified voltage to power the gate drive IC and other auxiliary circuits, eliminating the need for an external auxiliary power supply.
Solution Approach 2:
The circuit recovers and utilizes the voltage at the connection node between the high-withstand-voltage and low-withstand-voltage transistors, which would otherwise be wasted during switching operations. By rectifying and storing this voltage, the circuit converts previously discarded energy into useful power for auxiliary functions.
2Reliability
If existing auxiliary power supply circuits are used, then power supply function is provided, but voltage stability is poor and overvoltage issues occur
Solution Approach 1:
The auxiliary power supply capacitor is connected in parallel with the gate drive IC to preemptively store energy and buffer voltage fluctuations. This capacitor acts as a cushion against voltage spikes and instability before they can affect the gate drive IC operation.
Solution Approach 2:
The rectification element serves as an intermediary between the switching circuit and the auxiliary power supply capacitor, converting the alternating voltage at the connection node into a stable direct voltage that can be stored and used reliably by the gate drive IC.
3Reliability
If the auxiliary power supply circuit is added to improve power supply stability, then voltage stability improves, but the device complexity increases
Solution Approach 1:
The auxiliary power supply function is merged with the existing switching circuit by utilizing the connection node between the high-withstand-voltage and low-withstand-voltage transistors. This integration allows the circuit to generate its own auxiliary power without requiring a completely separate power supply system.
Solution Approach 2:
The connection node between the high-withstand-voltage and low-withstand-voltage transistors serves multiple functions: it is part of the main power switching path and simultaneously serves as the power source for the auxiliary power supply circuit through rectification and capacitor storage.
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 enhances power efficiency by effectively utilizing switching circuit power, reduces noise, and prevents overvoltage, thereby stabilizing the gate drive IC operation and minimizing power consumption.
Implementation Method 1
A rectification element RCT1 and an auxiliary power supply capacitor GDC1 are provided. A connection node CNN1 between the high-withstand-voltage transistor HVT1 and the low-withstand-voltage transistor LVT1 is connected to an anode of the rectification element RCT1. A cathode of the rectification element RCT1 is connected to a positive electrode of the auxiliary power supply capacitor GDC1.
Data Source
AI summary
An auxiliary power supply circuit connected to a switching circuit in which a high-withstand-voltage transistor and a low-withstand-voltage transistor are connected in series includes a rectification element and an auxiliary power supply capacitor. A connection node between the high-withstand-voltage transistor and the low-withstand-voltage transistor is connected to an anode of the rectification element. A cathode of the rectification element is connected to a positive electrode of the auxiliary power supply capacitor. A negative electrode of the auxiliary power supply capacitor is connected to a reference terminal of the low-withstand-voltage transistor.