Passive Gate-Driver Circuit for Series IGBT DC Breakers
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Solution Overview
Problem
Conventional DC circuit breakers require multiple gate drivers for each power device, leading to increased cost, reduced reliability, and inoperability in harsh environments due to complex circuitry and component redundancy.
Innovation Solution
A single passive gate-driver circuit architecture is implemented for series-connected power devices, utilizing insulated gate bipolar transistors (IGBTs) with shared gate resistors, diodes, metal-oxide varistors, and resistor-capacitor snubber circuits to simplify and reduce the number of components, enabling scalable and cost-effective DC circuit breaker designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple gate drivers are used for each power device, then the power devices can be controlled reliably, but the system complexity and cost increase
Solution Approach 1:
The patent combines multiple gate driver functions into a single gate driver circuit that controls series-connected power devices. The single gate driver uses shared resistors and capacitors to drive multiple IGBTs in series, eliminating the need for separate gate drivers for each device. This merging approach reduces component count and system complexity while maintaining reliable control of all power devices through coordinated gate voltage management.
Solution Approach 2:
The single gate driver is designed to perform multiple functions: it controls multiple series-connected power devices, provides voltage balancing across the series devices, and operates in harsh environments where multiple isolated power supplies would fail. The circuit uses universal components like shared RC networks and diodes that serve multiple purposes in the series configuration, making the system more robust and less complex.
2Ease of operation
If multiple gate drivers with isolated power supplies are used, then each device can be independently controlled, but the cost and component redundancy increase
Solution Approach 1:
The patent merges multiple isolated power supplies into a single shared power source that feeds the series-connected power devices. The single gate driver circuit shares resistors, capacitors, and other components across all series devices, dramatically reducing component quantity. The shared components are strategically positioned to provide necessary control functions for each device without requiring duplication.
Solution Approach 2:
The single gate driver and its associated components serve multiple devices simultaneously. The RC snubber circuits and diodes are configured to provide voltage balancing and protection for series-connected devices, making each component multi-functional. This universal approach maintains independent control capability while minimizing the total number of components required.
3Reliability
If conventional gate driver circuits are used, then the circuitry is well-established, but the system is inoperative in harsh environments
Solution Approach 1:
The single gate driver circuit is designed to be self-sufficient in harsh environments by eliminating multiple isolated power supplies that would fail independently. The circuit uses inherent properties of series-connected devices and passive components to maintain operation without requiring complex isolation or protection circuits for each device. The shared RC networks and diodes provide automatic voltage balancing and protection that works reliably in harsh conditions.
Solution Approach 2:
The patent changes the operational parameters by using a single gate driver voltage level that is distributed across series devices through passive component networks. Instead of maintaining multiple isolated voltage levels, the system uses a single voltage reference and distributes it through resistive and capacitive dividers, making the system more tolerant of harsh environmental variations while reducing complexity.
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 solution reduces system complexity, enhances reliability, and allows operation in harsh environments by eliminating unnecessary power supplies and fiber-optic devices, achieving higher power density and lower costs while mitigating voltage balancing and gate oscillation issues, thus improving stability and robustness.
Implementation Method 1
one or more metal-oxide varistors (MOVs) connected in parallel to at least one of the first IGBT and the second IGBT
Implementation Method 2
one or more resistor-capacitor (RC) snubber circuits connected in parallel to one or more of the first IGBT and the second IGBT
Data Source
AI summary
Gate control of power semiconductor devices using reduced gate drivers is disclosed. A circuit breaker may include a multitude of transistors, such as insulated gate bipolar transistors (IGBTs), connected in series with one another. Each transistor may be connected to a respective gate resistor. Diodes may be connected between various gate resistors. One or more resistor-capacitor (RC) snubber circuits may be provided in parallel with one or more of the transistors. Likewise, one or more metal-oxide varistors (MOVs) may be connected in parallel to one or more of the transistors. A gate driver (e.g., a single gate drive) may be connected to the one or more diodes and an emitter of at least one of transistors.