Braking Resistor Bridge Circuit for Redundant DC Link Interruption
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Solution Overview
Problem
Existing circuit arrangements for electric vehicles with DC voltage supplies and braking resistors lack redundancy in energy supply interruption, leading to potential faults and inefficiencies during braking operations.
Innovation Solution
A circuit arrangement featuring a multi-phase bridge power converter with multiple half-bridge circuits and inductively coupled coils, where braking resistor terminals are connected to the middle taps of these circuits, allowing for redundant energy supply interruption and improved fault tolerance through staggered switching of partial branches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single braking resistor connection is used in the DC voltage intermediate circuit, then the circuit structure is simple, but the reliability is reduced due to lack of redundancy in energy supply interruption
Solution Approach 1:
The braking resistor connection is segmented into multiple independent paths by connecting it to middle taps of different half-bridge circuits. This segmentation creates redundant energy supply interruption options, where each half-bridge circuit can independently control energy dissipation through the braking resistor, thereby improving reliability without significantly increasing overall system complexity.
2Reliability
If multiple half-bridge circuits are used to provide redundant braking resistor connections, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The half-bridge circuits are designed to serve multiple functions: they participate in normal power conversion operations and simultaneously provide redundant braking resistor connections. This multi-functionality allows the same circuit components to enhance reliability during braking operations without adding separate dedicated redundancy components, thereby improving fault tolerance while controlling device complexity.
3Reliability
If braking resistor terminals are connected to middle taps of bridge circuits, then redundant energy supply interruption is achieved, but the manufacturing precision requirements increase
Solution Approach 1:
The middle taps of the half-bridge circuits serve as equipotential connection points that naturally divide the DC voltage intermediate circuit into symmetric sections. By connecting braking resistor terminals to these equipotential middle taps, the circuit achieves balanced voltage distribution and redundant energy supply interruption paths, while the standardized middle tap locations simplify manufacturing precision requirements compared to arbitrary connection points.
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 enhances redundancy and reduces faults in the DC voltage intermediate circuit, minimizing spurious radiation and ensuring continued operation even if one partial branch fails, thereby improving the reliability of energy dissipation during braking.
Implementation Method 1
a first coil is arranged in the positive branch of the DC voltage intermediate circuit, a second coil is arranged in the negative branch of the DC voltage intermediate circuit, and both coils are preferably inductively coupled
Implementation Method 2
One option, which can also be provided together with other options, is to convert this energy into heat in a braking resistor
Data Source
AI summary
A circuit arrangement and a method with a DC voltage supply, a DC voltage intermediate circuit, a power converter, a control device for the power converter, and with a braking resistor. The power converter is formed as a multi-phase bridge circuit having at least one, preferably at least two first half bridge circuit(s) and having at least one, preferably at least two second half bridge circuit(s), which are each connected to the DC voltage intermediate circuit. A first resistor terminal of the braking resistor is connected to the middle tap of the first bridge circuit, and wherein a second resistor terminal of the braking resistor is connected to the middle tap of the second bridge circuit.