Inverter-Controlled Reel Deceleration via Electrical Torque
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Solution Overview
Problem
Existing post-processing machines in the paper industry face challenges in efficiently decelerating machine reels during web breaks, leading to material loss and mechanical brake damage due to the inability to adjust deceleration power and the risk of fires from heat generation.
Innovation Solution
A method and apparatus that continuously determine the inertia and angular speed of the machine reel to calculate the required deceleration torque, allowing for electrical deceleration with optional mechanical brake assistance, reducing mechanical brake load and heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a mechanical brake is used to decelerate the machine reel at high rotation speeds, then the machine reel can be stopped, but the mechanical brake is damaged due to excessive power and heat generation
Solution Approach 1:
The patent replaces the mechanical brake system with an electrical braking system using the unwinder motor. The motor is controlled to provide deceleration torque through electrical means, eliminating the need for mechanical friction-based braking at high speeds. This substitution prevents mechanical brake damage while achieving effective deceleration.
Solution Approach 2:
The patent changes the braking mechanism from mechanical to electrical by adjusting motor control parameters. The motor's torque output is dynamically adjusted based on the machine reel's rotation speed and inertia, allowing controlled deceleration without the physical contact and heat generation associated with mechanical brakes.
2Speed
If a mechanical brake is used to stop the machine reel, then the machine reel can be made unrotational, but excessive heat is generated creating fire hazard
Solution Approach 1:
The patent replaces the heat-generating mechanical brake with an electrical braking system. The motor converts kinetic energy into electrical energy during deceleration, which can be dissipated or recovered, avoiding the thermal hazards associated with mechanical friction braking.
Solution Approach 2:
The patent converts the harmful kinetic energy of the rotating machine reel into useful electrical energy through regenerative braking. The motor acts as a generator during deceleration, converting mechanical energy into electrical energy that can be fed back to the power system, thus transforming a potentially dangerous energy release into a beneficial energy recovery process.
3Power
If the mechanical brake capacity is increased to handle high speed deceleration, then deceleration effectiveness improves, but the brake becomes unusable due to damage
Solution Approach 1:
The patent replaces the mechanical brake system with an electrical braking system that can provide high deceleration power without the physical limitations of mechanical components. The motor control system can dynamically adjust torque output to provide sufficient deceleration power while avoiding the wear and damage issues of mechanical brakes.
Solution Approach 2:
The patent implements dynamic control of the motor torque during deceleration. The control system continuously adjusts the motor's torque output based on real-time parameters such as rotation speed and inertia, allowing optimal deceleration performance while preventing overload conditions that would damage mechanical brakes.
4Ease of repair
If electrical deceleration is used instead of mechanical brake, then mechanical brake wear is reduced, but additional control complexity is required
Solution Approach 1:
The patent makes the motor serve multiple functions: it acts as both a drive motor during normal operation and as a braking device during deceleration. This multi-functionality eliminates the need for separate mechanical brake components and their associated maintenance, while the control logic for braking can be integrated into the existing motor control system.
Solution Approach 2:
The motor automatically provides deceleration torque through electrical control without requiring external mechanical braking components. The system uses its own motor to perform the braking function, eliminating the need for separate brake mechanisms and reducing maintenance 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 approach enables controlled and efficient deceleration, minimizing material loss, reducing mechanical brake wear, and enhancing safety by adjusting deceleration torque and utilizing electrical means to return energy to the network, thus improving production efficiency and safety.
Implementation Method 1
decelerating the machine reel electrically in accordance with the determined torque
Implementation Method 2
mechanical brakes transform the energy bound to the machine reel into heat that heats the brakes
Data Source
AI summary
A method and apparatus are provided for decelerating an inverter-controlled machine reel in a paper machine. The method includes detecting a break in a paper web from a machine reel, determining the inertia of the machine reel, determining continuously the angular speed of the machine reel, and determining continuously the torque required to decelerate the machine reel, on the basis of the determined inertia and angular speed, for the purpose of stopping the machine reel in a predefined time. The method also includes decelerating the machine reel electrically to stop the machine reel, in accordance with the determined torque, and using a mechanical brake when the rotation speed of the machine reel is lower than a predefined rotation speed and when the torque obtained by electrical deceleration is too small to stop the machine reel in a predefined time.