High-Power Motor Control for Shredding Plants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-power electric motors in shredding plants experience power peaks during variable load conditions, leading to inefficiencies, network disturbances, and the need for oversized components, which limits productivity and increases costs.
Innovation Solution
A control apparatus and method that selectively adjusts voltage and current to operate the electric motor in three modes: constant rotation speed, constant power, and constant torque, using an inverter with thyristors to manage power transfer and torque, ensuring maximum energy delivery while preventing power peaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the electric motor operates at high power to maximize productivity, then the rotation speed can be increased, but power peaks occur during variable load conditions causing network disturbances
Solution Approach 1:
The patent applies dynamics by making the motor operating characteristics adjustable through three distinct modes (constant speed, constant power, constant torque) that can be selected based on load conditions. This dynamic adaptability allows the system to maintain high productivity while preventing power peaks by switching to appropriate operating modes during variable load conditions
Solution Approach 2:
The patent changes the operating parameters of the electric motor by implementing three different control modes that modify speed, power, and torque characteristics. By changing these parameters dynamically based on actual load requirements, the system achieves both high productivity and network stability, avoiding the fixed-parameter limitations of conventional motors
2Reliability
If the electric motor is oversized to handle peak loads, then power peaks can be prevented, but the cost and complexity of the system increases
Solution Approach 1:
The patent applies partial action by providing just enough motor capacity for normal operation and using control strategies (three operating modes) to handle peak loads without requiring excessive motor oversizing. The constant torque mode allows the motor to deliver maximum torque at reduced speeds, providing peak load handling capability without needing a significantly larger motor
3Productivity
If the rotation speed is increased to improve productivity, then more material can be processed, but the torque required for crushing varies with load conditions
Solution Approach 1:
The patent makes the motor's speed-torque characteristics dynamic by implementing three selectable operating modes. The constant speed mode maximizes productivity for light loads, while the constant torque mode provides maximum crushing force for heavy loads. This dynamic adjustment allows the system to optimize both productivity and crushing capability based on actual material conditions
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 maximizes energy transfer to the shredding process, improves efficiency, and prevents power peaks, allowing the motor to operate at nominal power without damaging the network, thereby enhancing productivity and reducing costs by optimizing motor sizing.
Implementation Method 1
un known type and provided with an inverter, or more generally with any type of power supply system for the electric motor
Implementation Method 2
electric motor (12), the rotor of which is connected (18) to a rotating drum, or mill, (13)
Implementation Method 3
The rotating drum has a large mass, so that once it has been made to rotate by the electric motor, it rotates by inertia, due to the flywheel effect
Implementation Method 4
it rotates by inertia, due to the flywheel effect
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Control apparatus (10) and corresponding method for controlling a high power (P) electric motor (12), preferably of the order of megawatts (MW), preferably of or associated with a shredding plant (11) which is preferably usable for shredding very bulky and heavy objects and is provided with a rotating shredding member (13) connected to the rotor of the electric motor (12). A control circuit (20) is configured to control the electric motor (12) so that it can operate selectively in different operating modes.