US 11,448,701 B2Granted

Condition monitoring device for monitoring operations of motor

AssigneeABB Schweiz AG

InventorsPallavi Hujband, Maciej Orman, Cajetan Pinto

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Abstract

The present disclosure discloses a Condition Monitoring Device (CDM), configured to monitor power consumption and loading of motor. The CDM receives value of a measured current in a stator of the motor, and measures at least one of a magnetic flux around the motor and vibrations in the motor. The magnetic flux, the vibrations and the current in the stator are measured within a predefined time window. The CDM calculates various parameters of the motor and estimates a value of current using the measurements and rated parameters stored in the CDM. The estimated parameter of current is compared with the measured value of current. A value of rotor speed (one of the rated parameters) is varied until the value of the estimated current is approximately equal to the value of the measured current. The value of current is considered to monitor power consumption and loading of the motor.

Claims8

Dependent claims

A condition monitoring device, configured to monitor power consumption and loading of a motor, the condition monitoring device comprising:

a housing body configured to be affixed to a body of the motor;
an interface for receiving a value of a current (Im) in a stator of the motor, wherein the current (Im) is measured using at least one current measuring device;
at least one sensor housed within the housing body, for measuring a magnetic flux around the motor and vibrations in the motor, wherein the magnetic flux, the vibrations and the current (Im) are measured within a predefined time window;
a memory, configured to store values of one or more rated parameters of the motor, wherein the values of one or more rated parameters are predefined at a time of manufacture of the motor;
one or more processors configured to:
calculate a first slip (Sm) of the motor based the measured magnetic flux and the vibrations, and a second slip (Sr) of the motor at a rated load condition and a rated power (P.sub.i)rated, using the values of one or more rated parameters, wherein the one or more rated parameters comprise at least a rotor speed (Nr) at rated load condition;
calculate a value of new power (Pi) and a value of rotor current (Iload) based on the first slip (Sm), the second slip (Sr) and a value rated power (Pi)rated at rated load;
estimate a value of current (Iturn) based on the measured value of current (Im), a value of current (I0) calculated at no load condition, and the value of rotor current (Iload);
and
calibrate a value of the rotor speed (Nr) for tuning the value of current (Iturn) when the estimated value of current (Iturn) is outside a first range around the value of the measured current (Im), wherein consequently the value of current (Itune) is within the first range, for monitoring power consumption and loading of a motor,
wherein the magnetic flux, the vibrations and the current (Im) are measured when a temperature of the motor is stable with respect to variations of a load associated with the motor.

8 more elements

A method for configuring a condition monitoring device for monitoring power consumption and loading of a motor, the method comprising:

measuring at least one of a magnetic flux around a motor, vibrations in the motor, and a value of current (Im) in a stator of the motor using at least one sensor housed within a housing body of a condition monitoring device;
receiving one of, the value of a current (Im) in a stator of the motor upon measuring magnetic flux around the motor, and a value of magnetic flux around the motor upon measuring the value of current in the stator, wherein the current (Im), the magnetic flux and the vibrations are measured within a predefined time window;
calculating a first slip (Sm) of the motor based the measured magnetic flux and the vibrations, and a second slip (Sr) of the motor at a rated load condition and a value of rated power (Pi)rated, using values of one or more rated parameters stored in a memory of the condition monitoring device, the one or more parameters comprising at least a rotor speed (Nr) at rated load condition, wherein values of the one or more rated parameters are predefined at a time of manufacture of the motor;
calculating a value of new power (Pi) and a value of rotor current (I2_load) based on the first slip (Sm), the second slip (Sr) and a value of rated power (Pi)rated;
estimating a value of current (Itune) based on the value of measured current (Im), a value of current (I0) calculated at no load condition, and the value of rotor current (I2_load);
and calibrating a value of the rotor speed (Nr) when the estimated value of current (Itune) is outside a first range around the value of the measured current (Im), wherein consequently the value of current (Itune) is within the first range, for monitoring power consumption and loading of a motor
wherein tuning the value of current (Itune) comprises:
determining an angle (α) between the Ir and the I2 and an angle Φm) based on the (Im) and the (Pi);
calculating the value of current (Itune) based on a function (fn), wherein the function (fn) is a radicand with an index 2, and wherein the function comprises the value of current (Im) multiplied with a value of (Φm), the value of current (I0), the value of PF, the value of rotor current (I2_Load) and a value of cosine of (α);
and calibrating the value of rotor speed (Nr) based on value obtained by calculating a difference between the value of current (Itune) and the value of measured current (Im), wherein calibrating comprises varying the value of rotor speed (Nr) in regular intervals.

7 more elements

Dependencies are inferred from the claim text.