Variable Speed Accelerator Bypass Control for Inverter Failure
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Solution Overview
Problem
When an inverter breaks down, the rotation rate of the constant-speed motor and the driven rotary machine is spontaneously reduced, leading to over-rotation of the variable-speed motor due to its inertia, which is not effectively controlled by existing technologies.
Innovation Solution
A variable speed accelerator system with a planetary gear transmission device and a control method that includes a rotation rate controller, a bypass power source line, and switches to prevent over-rotation by supplying power to the variable-speed motor via the bypass line when the rotation rate controller fails, maintaining a predetermined rotation rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a rotation rate controller is used to control the variable-speed motor, then the rotation rate can be precisely controlled, but the system becomes vulnerable to inverter breakdown causing over-rotation
Solution Approach 1:
The patent sets up emergency protective measures in advance by providing a bypass power source line and over-rotation prevention device that activate when the rotation rate controller fails. This pre-prepared backup system prevents over-rotation damage during inverter breakdown without affecting normal controlled operation.
Solution Approach 2:
The bypass power source line acts as an intermediary component that provides an alternative power supply path when the main rotation rate controller fails. This intermediary system enables the variable-speed motor to operate in a controlled manner even when the primary control system is unavailable.
2Duration of action of moving object
If the variable-speed motor relies on inertia during inverter breakdown, then it can maintain rotation, but the rotation rate becomes uncontrollable and exceeds rated speed
Solution Approach 1:
The over-rotation prevention device continuously monitors the rotation rate of the variable-speed motor and provides feedback control. When the rotation rate exceeds the rated speed during inverter breakdown, the device automatically adjusts the bypass power supply to maintain rotation within safe limits, preventing uncontrolled over-rotation.
Solution Approach 2:
The system changes the operational parameters of the variable-speed motor by switching from controller-regulated speed to bypass-line-regulated speed. The over-rotation prevention device modifies the power supply parameters through the bypass line to maintain acceptable rotation rates even when the primary control system fails.
Data Source
AI summary
A variable speed accelerator includes an electric driving device and a transmission device. The electric driving device includes a constant-speed motor rotating a constant-speed input shaft of the transmission device in a first direction, and a variable-speed motor having a variable-speed rotor connected to a variable-speed input shaft of the transmission device and rotating an output shaft of the transmission device at a maximum rotation rate by rotating the variable-speed rotor at a maximum rotation rate in a second direction. The accelerator includes a power source line connecting the variable-speed motor with a power source so that the variable-speed motor rotates in the second direction, a rotation rate controller, and a bypass line connecting the variable-speed motor with the power source so that the variable-speed motor rotates in the first direction.