公开(公告)号：US4218879A

公开(公告)日：1980-08-26

申请号：US955520

申请日：1978-10-30

Applicant: Raymond L. Hagrman ,  Jack R. Sandridge ,  Paul D. Soete

Inventor： Raymond L. Hagrman ,  Jack R. Sandridge ,  Paul D. Soete

IPC: F01D21/02 ,  G01P1/10 ,  G01P3/489 ,  G05D13/04 ,  F02C9/04 ,  G01P3/56

CPC classification number: F01D21/02 ,  G01P1/103 ,  G01P3/489 ,  G05D13/04

Abstract: An overspeed protection system is provided which utilizes simplified construction for detecting overspeed conditions of a rotating device. In the preferred embodiment, a single up/down counter is employed in an overall sequence which includes a first time period during which the counter is counted up from a preselected value by a series of pulse representations of speed for the rotating device. After the expiration of the first time period of the sequence, the counter value is compared to an overspeed limit selected during the previous sequence. If that limit is exceeded, an overspeed condition is detected by the system. In a second time period of the overall sequence, the counter is down counted by the pulse representations of speed. After the expiration of the second predetermined time period of the sequence, the counter value is compared to the original preset value to determine the rate of change in device speed. If the rate of change exceeds some preselected value, a low overspeed limit is used for the overspeed limit of the next up count for the subsequent sequence. If the rate of change does not exceed the preselected value, a high overspeed limit is used for the overspeed limit of the next up count for the subsequent sequence. The system outputs an overspeed signal only if an overspeed is detected on consecutive up count/down count portions of a sequence.

Abstract translation: 提供了一种超速保护系统，其利用简化的结构来检测旋转装置的超速状况。 在优选实施例中，在整个序列中采用单个向上/向下计数器，该整个序列包括第一时间段，在该第一时间段期间，计数器通过用于旋转装置的速度的一系列脉冲表示从预选值向上计数。 在序列的第一个时间段到期后，将计数器值与先前序列中选择的超速限制进行比较。 如果超过该限制，系统会检测到超速状况。 在整个序列的第二个时间段内，计数器通过速度的脉冲表示进行计数。 在序列的第二预定时间段期满后，将计数器值与原始预设值进行比较，以确定设备速度的变化率。 如果变化率超过某个预选值，则对于后续序列，下一个向上计数的超速限制将使用较低的超速限制。 如果变化率不超过预选值，则对于后续序列的下一个向上计数的超速限制使用高超速限制。 仅当在序列的连续向上计数/下降计数部分检测到超速时，系统才输出超速信号。