Variable Speed Drive System Wear Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable speed drive systems suffer from wear in the main transmission, inability to control speed-adjustable drives during startup, and disruptive force transitions between speed-controllable and main drives, leading to inefficient operation and mechanical stress.
Innovation Solution
A variable-speed drive system with multiple frequency converters and a sophisticated switching device that allows for controlled speed changes and reduced load torque during startup, using mechanical or hydrodynamic coupling elements to separate the drive machine and transmission unit, and employing a bypass device to manage load characteristics, ensuring uninterrupted power transmission and reduced wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a variable-speed drive is mechanically coupled to the main transmission for starting, then the drive can be started up, but wear occurs in the main gearbox due to engagement
Solution Approach 1:
The patent extracts the starting function from the main drive system by introducing a separate variable-speed drive that is mechanically decoupled from the main transmission. This separate drive can be engaged and disengaged independently, providing starting capability without subjecting the main gearbox to wear from frequent engagement operations.
Solution Approach 2:
The patent introduces a differential mechanism as an intermediary between the main drive and the variable-speed drive. This differential allows smooth power transfer and speed adjustment during starting operations, eliminating the need for direct mechanical engagement that would cause wear in the main gearbox.
2Reliability
If a switch is used to disconnect the synchronous generator from the electrical supply network, then the generator can be isolated, but the switching causes interruption of traction
Solution Approach 1:
The patent employs a differential mechanism that dynamically balances the power flows between the main drive, variable-speed drive, and electrical network. During switching operations, the differential continuously adjusts the power distribution to maintain uninterrupted traction, eliminating the discontinuities caused by simple on/off switching.
Solution Approach 2:
The patent ensures continuous power transmission through the differential mechanism during all operating transitions. The differential maintains a continuous path for power flow between the drives and the load, ensuring that useful action (traction) continues without interruption during generator isolation or drive switching events.
3Adaptability or versatility
If the variable-speed drive is used for speed control, then adaptability is improved, but the drive cannot be controlled during startup of the main drive
Solution Approach 1:
The patent segments the control functions by providing independent control systems for the main drive and the variable-speed drive. The variable-speed drive has its own frequency converter and control circuitry, allowing it to be controlled during main drive startup. This segmentation enables the variable-speed drive to perform speed control functions independently while the main drive is being started.
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 system achieves low wear in the main transmission, allows control of speed-adjustable drives during startup, and provides uninterrupted force transitions, resulting in high efficiency and optimal use of mechanical and electrical components across a wide speed range, enhancing availability and reducing operational costs.
Implementation Method 1
The control machines (2.1, 2.2) and the drive machine (1) are each electrically connected to at least one frequency converter (120, 121)
Implementation Method 2
using mechanical or hydrodynamic coupling elements to separate the drive machine and transmission unit
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a variable speed drive system. The variable speed drive system has a drive machine (3) and a drive machine (1) which is mechanically coupled or can be coupled to the drive machine (3) by means of a transmission unit (17). Furthermore, at least two regulating machines (2.1, 2.2) are provided which are mechanically coupled or can be coupled to the transmission unit (17) and can each be operated using one of at least two frequency converters (120, 121). At least one of the at least two frequency converters (120, 121) is electrically connected or can be connected to the drive machine (1) by means of a changeover device (130) in such a way that a connection of the drive machine (1) to at least one electrical supply network (100, 110) is at least temporarily or permanently separable in order to generate an open-loop and/or closed-loop controlled speed change at the drive machine (1). In order to provide a variable speed drive system of this type, in which the wear occurring in the main transmission is kept as low as possible and that the variable speed drive or the differential drive is controllable during the starting of the main drive, and in which, in particular, the changeover between both the variable speed drive or the differential drive and the main drive is free of interruption of traction force.