Gate Driver Circuit Priming for Switched Reluctance Generators
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Solution Overview
Problem
Conventional switched reluctance generators require additional circuitry and components for priming, which increases cost, complexity, and size, as they lack self-fluxing capabilities and necessitate a priming circuit to initiate magnetic flux.
Innovation Solution
The use of gate drive circuits in the converter to provide a gate drive voltage to IGBTs and MOSFETs, allowing for the induction of a magnetic field in the generator coils without a dedicated priming circuit, thereby eliminating the need for additional voltage sources and circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated priming circuit with separate voltage source is used to initiate magnetic flux in the SR generator, then the SR generator can be primed successfully, but the converter complexity, size, and cost increase due to additional circuit components
Solution Approach 1:
The gate drive circuit is designed to perform dual functions: providing gate drive voltage to switch the IGBT during normal operation, and providing priming voltage to the bus to initiate magnetic flux in the SR generator during startup. This eliminates the need for a dedicated priming circuit with separate voltage source, reducing converter complexity while maintaining priming capability.
Solution Approach 2:
The patent combines the priming function with the existing gate drive circuit by adding a priming transistor that shares the gate drive voltage source. The gate drive circuit's voltage source is used to drive both the IGBT gate and the priming transistor, which connects the priming voltage to the bus. This merging of functions eliminates redundant components and simplifies the overall converter design.
2Reliability
If additional circuit components are added to enable priming functionality, then the SR generator can be started, but the converter size and cost increase
Solution Approach 1:
The gate drive circuit components, including the voltage source and control logic, are made multi-functional to serve both normal switching operations and priming functions. This eliminates the need for separate dedicated priming components, reducing the overall converter size while maintaining reliable startup capability.
Solution Approach 2:
The converter uses its own existing gate drive voltage source to provide the priming voltage, rather than requiring an external dedicated priming voltage source. The gate drive circuit serves itself by providing voltage for both its primary function (IGBT gate drive) and the priming function through the priming transistor, eliminating the need for additional external components.
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 reduces the complexity and cost of the converter design, enhances reliability, and results in a more compact form-factor by utilizing existing gate drive components for both gate drive and priming functions.
Implementation Method 1
providing the gate drive voltage on the bus via the MOSFET induces a magnetic field in one or more coils of the SR generator
Data Source
AI summary
An example converter for a switched reluctance (SR) generator includes one or more gate driver circuits that are not only used to synchronously control switches, such as insulated gate bipolar transistors (IGBTs) of the converter, but also used to provide priming function during start-up of the generator. Since, an SR generator does not have to ability to self provide magnetic flux, priming current is provided to coils of the SR generator to initiate a magnetic flux. By using the gate drive circuit to provide the priming current, an additional priming circuit is not required. As a result, the converter design is more streamlined, with reduced complexity, cost, and size. When a bus voltage of the converter is below a threshold level, the one or more gate drive circuits can provide the priming current on the bus to initiate the SR generator.