外文翻译--煤矿业带式输送机几种软起动方式的比较(编辑修改稿)

外文翻译--煤矿业带式输送机几种软起动方式的比较(编辑修改稿)内容摘要：

items would include motor brushes, bearings, brake pads, dissipation resistors, oils, and cooling water. If the drive system is conservatively engineered and operated, the lower stress on consumables will result in lower maintenance costs. Some drives require supporting systems such as circulating oil for lubrication, cooling air or water, environmental dust filtering, or puter instrumentation. The maintenance of the supporting systems can affect the reliability of the drive system. Cost The drive designer will examine the cost of each drive system. The total cost is the sum of the first capital cost to acquire the drive, the cost to install and mission the drive, the 大连交通大学信息工程学院 2020 届本科毕业生毕业设计 (论文 )外文翻译 4 cost to operate the drive, and the cost to maintain the drive. The cost for power to operate the drive may vary widely with different locations. The designer strives to meet all system performance requirements at lowest total cost. Often more than one drive system may satisfy all system performance criterions at petitive costs. Complexity The preferred drive arrangement is the simplest, such as a single motor driving through a single head ,mechanical, economic,and functional requirements often necessitate the use of plex belt designer must balance the need for sophistication against the problems that acpany plex systems. Complex systems require additional design engineering for successful deployment. An oftenoverlooked cost in a plex system is the cost of training onsite personnel, or the cost of downtime as a result of insufficient training. SOFT START DRIVE CONTROL LOGIC Each drive system will require a control system to regulate the starting mechanism. The most mon type of control used on smaller to medium sized drives with simple profiles is termed Open Loop Acceleration Control. In open loop, the control system is previously configured to sequence the starting mechanism in a prescribed manner, usually based on time. In open loop control, driveoperating parameters such as current, torque, or speed do not influence sequence operation. This method presumes that the control designer has adequately modeled drive system performance on the conveyor. For larger or more plex belts, Closed Loop or Feedback control may he utilized. In closed loop control, during starting, the control system monitors via sensors drive operating parameters such as current level of the motor, speed of the belt, or force on the belt, and modifies the starting sequence to control, limit, or optimize one or wore parameters. Closed loop control systems modify the starting applied force between an empty and fully loaded conveyor. The constants in the mathematical model related to the measured variable versus the system drive response are termed the tuning constants. These constants must be properly adjusted for successful application to each conveyor. The most mon schemes for closed loop control of conveyor starts are tachometer feedback for speed control and load cell force or drive force feedback for torque control. On some plex systems, It is desirable to have the closed loop control system adjust itself for various encountered conveyor conditions. This is termed Adaptive Control. These extremes can involve vast variations in loadings, temperature of the belting, location of the loading on the profile, or multiple drive options on the conveyor. There are three mon 大连交通大学信息工程学院 2020 届本科毕业生毕业设计 (论文 )外文翻译 5 adaptive methods. The first involves decisions made before the start, or 39。 Restart Conditioning39。 . If the control system could know that the belt is empty, it would reduce initial force and lengthen the application of acceleration force to full speed. If the belt is loaded, the control system would apply pretension forces under stall for less time and supply sufficient torque to adequately accelerate the belt in a timely manner. Since the belt only became loaded during previous。