Link Capacitor Surge Protection Circuit for Compact Electric Drives
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Solution Overview
Problem
Reducing the size of link capacitors in electric machines to minimize costs and installation space leads to voltage surges that can damage or destroy them, necessitating a solution to limit these surges.
Innovation Solution
A voltage surge protector is connected in parallel to the link capacitor, comprising a circuit breaker and resistor in series, controlled by a comparator circuit and timer, to manage and drain excess current through a resistor, thereby reducing voltage surges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the link capacitor size is reduced to minimize costs and installation space, then cost and installation space are improved, but voltage surges increase which can damage or destroy the capacitor
Solution Approach 1:
The patent introduces a voltage surge protector as an intermediary component between the inverter circuit and the link capacitor. This protector includes a circuit breaker and resistor that activate when voltage exceeds a threshold, providing a controlled discharge path for excess voltage and protecting the capacitor from damage despite its reduced size
Solution Approach 2:
The voltage surge protector is pre-configured with a circuit breaker and resistor specifically designed to activate before the voltage surge can damage the capacitor. The circuit breaker is set to close when voltage reaches a critical level, creating a protective mechanism that cushions the capacitor against harmful voltage spikes
2Quantity of substance
If the link capacitor size is reduced to minimize costs and installation space, then cost and installation space are improved, but reliability deteriorates due to increased vulnerability to voltage surges
Solution Approach 1:
The voltage surge protector acts as a protective intermediary that monitors voltage levels and activates a discharge path through the circuit breaker and resistor when voltage exceeds safe thresholds, thereby protecting the reduced-size capacitor from damage and maintaining system reliability
Solution Approach 2:
The circuit breaker is controlled by a feedback mechanism that continuously monitors the voltage across the link capacitor. When voltage exceeds a predetermined threshold, the feedback signal triggers the circuit breaker to close, creating a controlled discharge path that limits voltage surge and protects the capacitor
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
Effectively limits voltage surges by draining excess current, protecting the link capacitor from damage and ensuring safe operation of the electric machine.
Implementation Method 1
The electricity flowing through the resistor is converted to heat and discharged from the circuit configuration
Data Source
AI summary
A circuit configuration includes a voltage surge protector that is connected in parallel to the link capacitor to protect the link capacitor from voltage overloads. A printed circuit board assembly, an electric axle drive, and a motor vehicle are also disclosed.