Frequency Converter Assembly with Dual-Use Brake Terminals
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Solution Overview
Problem
The existing design of frequency converters with brake chopper switches requires a large number of terminals for connecting external brake resistors, leading to increased space requirements and manufacturing costs.
Innovation Solution
A frequency converter assembly where the brake chopper switch is continuously in the closed position, allowing the use of terminals for both connecting external brake resistors and providing direct-current supply, and enabling the connection of an external brake chopper unit with its own switch for controlled braking, thereby reducing the number of components and space needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the frequency converter is provided with both terminals for connecting external brake resistors and poles for direct-current supply, then the braking function and direct-current supply function are both achieved, but the number of terminals increases leading to increased space requirements and manufacturing costs
Solution Approach 1:
The patent applies multi-functionality by enabling the brake resistor terminals to serve dual purposes: connecting external brake resistors for motor braking and providing direct-current supply connections. The control unit intelligently switches between braking mode and direct-current supply mode, allowing the same physical terminals to fulfill different functional roles based on operational requirements, thereby eliminating the need for separate dedicated terminals for each function.
2Device complexity
If the brake chopper switch is continuously in the closed position, then the terminals can be used for both braking and direct-current supply, but the braking control precision may be affected
Solution Approach 1:
The patent applies dynamics by making the brake chopper switch state configurable rather than fixed. The control unit can dynamically adjust the switch between continuously closed position (for direct-current supply operation) and controlled switching position (for precision braking operation). This dynamic adaptability allows the system to optimize between component simplification and control precision based on the specific operational mode required.
Solution Approach 2:
The patent applies parameter changes by allowing the operational parameters of the brake chopper switch to be modified. The control unit can change the switch's duty cycle and timing characteristics depending on whether braking precision is required or if the terminals are being used for direct-current supply. This parameter adjustability enables the same hardware to meet different performance requirements.
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 configuration allows for a more compact design with lower manufacturing costs while maintaining effective braking capabilities and direct-current supply functionality.
Implementation Method 1
current flows from the positive branch of the direct-voltage intermediate circuit to the negative branch of the direct-voltage intermediate circuit via the brake resistor
Data Source
AI summary
A frequency converter assembly comprising a direct-voltage circuit and brake chopper means, the direct-voltage circuit including a first branch (DC+) and a second branch (DC−), and the brake chopper means including a first terminal (BRK+), a second terminal (BRK−), a brake chopper switch (S1) and control means (2). The brake chopper switch (S1) is arranged in its closed position to provide a braking connection, in which the first branch (DC+) is electrically connected to the first terminal (BRK+) and the second branch (DC−) is electrically connected to the second terminal (BRK−). The assembly is provided with a first operating state where the control means (2) are arranged to control the brake chopper switch (S1) selectively to the closed position and the open position in response to the desired power supply direction of the direct-voltage circuit. The assembly is further provided with a second operating state where the control means (2) are arranged to maintain the brake chopper switch (S1) continuously in the closed position.