Power Supply Circuit Voltage Abnormality Detection
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Solution Overview
Problem
Conventional power supply circuits for inverter systems require multiple circuits for abnormality judgment, leading to increased component count, complexity, and cost due to differences in arm and reference potentials among switching elements, necessitating a simpler method for voltage abnormality detection.
Innovation Solution
A power supply circuit that uses feedback control to monitor output voltages, allowing for unified voltage monitoring across multiple switching elements, with a monitoring circuit comparing subject voltage to a reference voltage to detect abnormal conditions and stop control signals to protect switching elements, thereby simplifying the circuit configuration and reducing component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple independent power supply circuits are provided for each switching element, then reliable voltage supply and abnormality detection are achieved, but device complexity and component count increase
Solution Approach 1:
The patent merges multiple independent power supply circuits into a single unified power supply circuit that serves multiple switching elements. The circuit uses a common voltage detection mechanism where the detected voltage is shared across all switching elements, eliminating the need for separate detection circuits for each element while maintaining reliable voltage supply and abnormality detection.
Solution Approach 2:
The power supply circuit is designed with universal functionality to serve multiple switching elements simultaneously. The voltage detection output can be applied to multiple switching elements, and the circuit structure allows it to monitor and control voltages for different arms and switching elements through a single unified mechanism, reducing overall system complexity.
2Reliability
If separate abnormality judgment circuits are provided for each switching element, then accurate abnormality detection is achieved, but component count and manufacturing cost increase
Solution Approach 1:
The patent combines multiple abnormality judgment functions into a single detection circuit. The voltage detection circuit generates a single detection output that can be used to judge abnormalities for multiple switching elements, thereby reducing component count and manufacturing cost while maintaining detection accuracy through the shared detection mechanism.
3Ease of operation
If multiple power supply circuits with different reference potentials are provided, then proper voltage control for each switching element is achieved, but circuit configuration complexity increases
Solution Approach 1:
The patent applies equipotentiality by providing a common reference potential to all switching elements through the unified power supply circuit. This eliminates the need for multiple independent reference potential circuits while maintaining proper voltage control precision, as the common reference potential ensures consistent voltage levels across all switching elements.
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 solution enables reliable detection of voltage abnormalities in a simple circuit configuration, effectively protecting switching elements from abnormal heat generation and malfunction by stopping gate voltage supply, while maintaining stable operation and reducing the risk of component breakdown.
Implementation Method 1
a switching element 12 and a controller 13. The rectification circuit 11 rectifies AC voltage supplied from a commercial AC power supply 4 in full-wave. The switching element 12 switches on and off in response to a PWM signal from the controller 13
Implementation Method 2
The rectification circuit 11 rectifies AC voltage supplied from a commercial AC power supply 4 in full-wave
Implementation Method 3
a smoothing capacitor C0. The switching element 12 switches on and off in response to a PWM signal from the controller 13, thereby converting the AC voltage into DC voltage
Implementation Method 4
A series unit composed of a zener diode 55 and a light emitting diode 56d provided on the input side of the photocoupler 56 is connected between the two electric paths 53 and 54
Implementation Method 5
a light emitting diode 56d provided on the input side of the photocoupler 56 is connected between the two electric paths 53 and 54
Implementation Method 6
a photocoupler 56 for driving a gate (hereinafter, abbreviated as a driving coupler) gives gate voltage (for example, 15V for ON instruction) to an IGBT 52
Data Source
AI summary
An object of the present invention is to provide a power supply circuit capable of reliably detecting voltage abnormality with a simple circuit configuration. According to the present invention, a power supply circuit that supplies control supply voltage for giving a control signal to a switching element is provided with: a switching power supply (1) having a function of supplying the control supply voltage to the switching element by a required number of output circuits (1b, 1c) and a function of feedback control that keeps output voltage of an output circuit (1a) constant; and a monitoring circuit (3) that monitors the control supply voltage based on output voltage of the output circuit (1a) used for feedback control, and in the case of abnormality, outputs a signal for stopping output of the control signal, to a CPU (8) which is a control apparatus for the switching element (71, 72).