Variable Speed Accelerator Braking Circuit for Inverter Failure
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Solution Overview
Problem
In variable speed accelerators, when an inverter breaks down, the rotation rate of the constant-speed motor and the driven rotary machine is reduced, leading to over-rotation of the variable-speed motor due to its larger rated rotation rate.
Innovation Solution
A braking circuit is integrated into the variable speed accelerator, connected between the variable-speed motor and the rotation rate controller, which applies a direct current to brake the variable-speed motor and prevent over-rotation when the inverter fails.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a variable-speed motor with larger rated rotation rate is used to enable speed control, then speed control capability is improved, but over-rotation occurs when the inverter breaks down
Solution Approach 1:
A braking circuit is pre-configured in the system that can be activated when inverter failure is detected. This preliminary preparation ensures that when the variable-speed motor loses speed control capability due to inverter breakdown, the braking circuit can immediately apply braking force to prevent over-rotation, maintaining system reliability without sacrificing speed control capability during normal operation.
2Duration of action of moving object
If the rotation rate of the variable-speed motor is determined by the inertia of the rotary machine, then the motor may continue rotating at high speed, but this leads to over-rotation exceeding rated rotation rate
Solution Approach 1:
The braking circuit provides a counteracting braking force that opposes the惯性-driven rotation of the variable-speed motor when the inverter fails. By applying this preliminary anti-action through the braking mechanism, the system prevents the harmful over-rotation that would otherwise occur due to the motor's inertia and the connected rotary machine's momentum.
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 braking circuit effectively prevents over-rotation of the variable-speed motor by braking it when the rotation rate controller breaks down, ensuring stable operation even in the event of inverter failure.
Implementation Method 1
A braking circuit is integrated into the variable speed accelerator, connected between the variable-speed motor and the rotation rate controller, which applies a direct current to brake the variable-speed motor
Data Source
AI summary
The present invention provides a variable speed accelerator including: a constant-speed motor (51) having a constant-speed rotor (52) which is configured to rotate a constant-speed input shaft (Ac) of a transmission device (10) in a first direction; and a variable-speed motor (71) which has a variable-speed rotor (72) connected to a variable-speed input shaft (Av) of the transmission device (10), having a cylindrical shape centered on an axis with a shaft insertion hole (74) passing therethrough in the axial direction through which the constant-speed input shaft (Ac) inserted, and configured to rotate an output shaft (Ao) at a maximum rotation rate by rotating the variable-speed rotor (72) at a maximum rotation rate in a second direction opposite to the first direction, wherein the variable speed accelerator further includes an AC power source line (110) which connects the variable-speed motor (71) with an AC power source to allow the variable-speed motor (71) to rotate in the second direction; a rotation rate controller (100) which is provided on the AC power source line (110) to control a rotation rate of the variable-speed motor (71); a first switch (SW1) provided on the AC power source line (110); and a braking circuit (2) connected to portions locating between the variable-speed motor (71) and the rotation rate controller (100) with the first switch (SW1) on the AC power source line (110).