A method for detecting an electrical fault in the stator of an electric machine is provided, wherein the stator includes multiple groups of windings, wherein the windings of each group are assigned to a respective phase of the electric machine, including the steps of: determining a respective current firstly between a subgroup of one of the groups of windings and a distinct further subgroup of the same group of windings and/or secondly between a subgroup of one of the groups of windings and a neutral point, and/or thirdly between a neutral point and either a further neutral point or to a common neutral point connected to at least the neutral point and the further neutral point, evaluating a fault condition, wherein the fulfilment of the fault condition depends on the respective determined current, and outputting a fault signal to personal and/or a device when the fault condition is fulfilled.

Disclosed according to embodiments are a motor control device and a fault diagnosis method using the same. The motor control device includes a first reception circuit which receives a first input signal through a first signal line, a second reception circuit which receives a second input signal through a second signal line, a sensing circuit which is connected to the first signal line and the second signal line and outputs a state output value which varies according to whether the second signal line is opened, and a micro control unit (MCU) which receives the state output value output from the sensing circuit and determines whether the second signal line is opened using the received state output value.

A motor control device controls a drive of a motor having a motor winding includes an angle calculation unit, a drive control unit, and an abnormality diagnosis unit. The angle calculation unit acquires a detected value from a rotation angle sensor that detects a rotation angle of the motor and calculate the rotation angle of the motor. The drive control unit controls the drive of the motor based on the rotation angle of the motor. When an abnormality in the rotation angle of the motor is detected while the motor is being driven, the abnormality diagnosis unit performs an abnormality diagnosis of an energized system while maintaining an energized state.

A method for tracking time in use of a generating set includes furnishing at least one piece of information characteristic of an operating time of said generator set. An autonomous device for measurement is solidly attached to a chassis of said generator set and has at least two sensors. One sensor is for measurement of a first physical magnitude. Another sensor is for measurement of a second physical magnitude. The anonymous device performs analysis of said first and second physical magnitudes provides for delivering a piece of information representative of an operating state of said generator set, determination of a piece of information representative of a global operating time of said generator set by cumulative time during which said representative information of an operating state is furnished, and storage of said piece of information representative of a global operating time of said generator set.

A method for tracking time in use of a generating set includes furnishing at least one piece of information characteristic of an operating time of said generator set. An autonomous device for measurement is solidly attached to a chassis of said generator set and has at least two sensors. One sensor is for measurement of a first physical magnitude. Another sensor is for measurement of a second physical magnitude. The anonymous device performs analysis of said first and second physical magnitudes provides for delivering a piece of information representative of an operating state of said generator set, determination of a piece of information representative of a global operating time of said generator set by cumulative time during which said representative information of an operating state is furnished, and storage of said piece of information representative of a global operating time of said generator set.

The purpose of the present invention is to provide a device monitoring technique having little restriction even on application to an already-existing device or facilitating monitoring even when a device to be monitored is in variable speed operation or under load variation. One of the representative device monitoring devices of the present invention monitors a device system using, as a power source, an AC electric motor driven by an inverter and is provided with a torque current estimation unit and a state estimation unit. The torque current estimation unit acquires information about AC currents of at least two phases and excitation current of the AC electric motor and calculates a torque current estimated value of the AC electric motor on the basis of the AC currents and the excitation current. The state estimation unit estimates the state of the device system from information including at least one of the feature amounts extracted from the torque current estimated value.

An arrangement for generating electric energy comprises an alternator having a rotor with a winding for being magnetized by an electric current fed therethrough and a stator with at least three stator windings for generation of three phase voltages therein upon rotation of the magnetized rotor in the stator. A rectifier has an input connected to the stator windings. Means is configured to measure the development over time of the difference of two of said phase voltages and an evaluation unit is configured to evaluate the result of this measurement to determine the functionality of the alternator. A control unit located remote to the alternator controls the rotor current.

The characteristics of a winding to be tested is allowed to be analyzed more easily and in a shorter time. A testing instrument 1 includes an impulse voltage application capacitor Cs having one end connected to an external terminal T2, a switch SW and a current limiting resistor Rs connected in series between another end of the impulse voltage application capacitor Cs and an external terminal T1, and a parameter calculator 5. The parameter calculator 5 calculates at least one of the value of the equivalent capacitor Cd, the value of the equivalent inductor Ld and the value of the equivalent resistor Rd by performing regression analysis using a measured value of a voltage Vcd in an analysis time period Ta from turning on of the switch SW to start of resonance based on the equivalent inductor Ld, the equivalent capacitor Cd and the equivalent resistor Rd pertaining to a winding 11.

Disclosed is a method and apparatus for real-time estimation of full parameters of a permanent magnet synchronous motor. According to this method and apparatus, it is possible to estimate in real time all four parameters of a permanent magnet synchronous motor without additional signal injection. In addition to the state equation, the “stator current ripple model” is additionally used to fundamentally solve the rank deficiency problem in the state equation without injecting additional signals. All four parameters of a permanent magnet synchronous motor can be estimated in real time.

According to one embodiment, an inspection system inspects equipment including a first structural object and a second structural object. The first structural object extends in a first direction. The second structural object is provided around the first structural object. The second structural object has a first surface opposing the first structural object. A first protrusion is provided in the first surface. The first protrusion extends in the first direction. The system includes a robot and a controller. The robot includes an imager. The robot moves between the first structural object and the second structural object. The imager images the first protrusion. The controller detects, from a first image acquired by the imager, a first edge portion of the first protrusion in a circumferential direction around the first direction. The controller controls a movement of the robot by using the detected first edge portion.