초록 ▼

An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are

An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are directly related to the motion of the valve relative to its seat. Signal processing apparatus analyzes the vibrations to recover the rotations of the rotating elements and thus the motion of the valve plug. Lost motion can also be determined (if a lost motion connection exists) by demodulating the vibration signal and thus taking into account also the lost motion. Simultaneously, the forces applied to the valve are estimated by estimating the torque between the stator and the rotor of the motor. Such torque can be estimated from measuring the input current and voltage alone, using a forgetting factor and a correction for the forgetting factor. A signature derived from relating the torque to the valve position can be used to assess the condition of the MOV, by comparing the signature to signatures for MOVs of known conditions. The vibration analysis components generate signals that relate to the position of elements in the operator. Similarly, the torque estimator estimates the torque output by any type of electric motor, whether or not part of an MOV analysis unit.

대표청구항 ▼

An apparatus for generating a parametric signature signal that corresponds to an operational aspect of a motor operated valve (an “MOV”), the MOV having: I. an electric motor, having input electrical connections, a stator, a rotor and an output shaft; II. within a housing, a first gear pair having a

An apparatus for generating a parametric signature signal that corresponds to an operational aspect of a motor operated valve (an “MOV”), the MOV having: I. an electric motor, having input electrical connections, a stator, a rotor and an output shaft; II. within a housing, a first gear pair having a first gear and a second gear, the first gear being coupled to said output shaft; and III. a valve plug that is coupled to the second gear and that is movable, relative to a valve seat, in response to rotation of the output shaft; said signature signal generating apparatus comprising: a. vibrationally coupled with said housing, a vibrations pickup arranged to generate an electromagnetic signal that corresponds to vibration of said housing (designated a “housing signal”); b. electromagnetically coupled with the output of said vibration pickup, a vibration analyzer, which generates a position signal that corresponds to an estimate of the position of at least one element of said MOV that is coupled to said first gear, with respect to time; c. a torque estimator, which generates a signal that corresponds to an estimate of the torque between the stator and the rotor of said motor with respect to time (designated the “torque estimate signal”); and d. a system analyzer, coupled to the outputs of the torque estimator and the vibration analyzer, which system analyzer generates a signature signal that corresponds to the relation between the motor torque and the at least one MOV element position.