Provided is a deterioration diagnosis system which diagnoses deterioration of an N-phase rotational machine (N denotes a natural number). The deterioration diagnosis system includes a first current sensor to be attached individually to at least lead wires of (N-1)-phases in a rotational machine, the first current sensor being able to detect a current amplitude arising from a plurality of deterioration causes, and a second current sensor to be attached collectively to the lead wires of all phases in the rotational machine, the second current sensor being able to detect a current amplitude arising from a plurality of deterioration causes.

A refrigeration system includes a compressor and a capacitor electrically coupled to the compressor. A method of operating the refrigeration system includes measuring voltage values based on alternating current power powering the compressor. The method includes measuring current values based on the alternating current power. The method includes determining, with a controller, a power factor value based on at least one of the voltage values and at least one of the current values. The method includes receiving a supply air temperature value from an air temperature sensor installed in the refrigeration system. The method includes receiving a return air temperature value from an air temperature sensor installed in the refrigeration system. The method includes determining a temperature split based on a difference between the return and supply air temperature values. The method includes determining a fault in the capacitor based on the power factor value and the temperature split.

A system for monitoring the status of a vehicle utilizing a monitoring unit and a receiver unit. The monitoring unit is operatively connectable to the vehicle via a diagnostic port and detects the voltage output by the vehicle's battery when the vehicle's engine is turned on and off, and voltage output by the alternator while the engine is running. From these voltage measurements, the monitoring unit determine the operational status of the vehicle's battery and alternator by comparison to predefined criteria, such as optimal voltage ranges or a threshold minimum voltage. When the monitoring unit detects that the vehicle's battery or alternator may be malfunctioning, a signal indicating a malfunction is transmitted to the receiver unit, for example the driver's cellular phone, which will generate a warning notification alerting the operator to the existence and component responsible for the malfunction.

A failure diagnostic apparatus for current sensors of a 3-phase brushless AC (BLAC) motor may include: a 3-phase BLAC motor; current sensors each configured to measure a phase current of the 3-phase BLAC motor; a motor driving unit configured to drive the 3-phase BLAC motor; and a control unit configured to drive the 3-phase BLAC motor through the motor driving unit, periodically calculate a phase current error using the phase current fed back through each of the current sensors, and diagnose that a failure occurred in the current sensor of the corresponding phase, when an error count accumulated during a preset time reaches a preset value, based on the phase current error.

An apparatus for use with a dynamoelectric machine includes a main body configured for attachment to a brush holder. A proximity sensor is on the main body, and the proximity sensor is configured for detecting the presence of a brush located at least partially inside the brush holder. The apparatus receives power from a battery located inside the apparatus, and transmits a wireless signal. The wireless signal is transformable into an indication of a remaining life of the brush. The apparatus is configured to be fully operational when the dynamoelectric machine is neither energized nor in operation, as the apparatus receives power from the battery.

An anomaly diagnosis system is provided that includes: a current-value obtaining part 111 that obtains a value of an AC current inputted to or outputted from a device to be diagnosed; a frequency analyzing part 112 that converts the current values obtained at intervals into a frequency spectrum which correlates a current intensity with a frequency; an anomaly-judging-value calculating part 113 that calculates at intervals a frequency width of the frequency spectrum at a current intensity “As” satisfying As=m×At (0<m<1), where “At” is a peak current intensity associated with an analysis frequency which is an integer multiple of a frequency of the AC current; and a judging part 114 that judges whether the frequency width is wider than that in a normal condition and, if it holds true, judges that the device is in an anomalous condition.

A stability measuring method for a synchronous generator includes: S11: collecting electrical quantities, and setting an alarm PQ curve of the synchronous generator; S12: calculating a dynamic reactive power reserve, an inductive dynamic reactive power reserve and a capacitive dynamic reactive power reserve of the synchronous generator; S13: calculating a dynamic reactive power reserve target value, an inductive dynamic reactive power reserve target value and a capacitive dynamic reactive power reserve target value of the synchronous generator; and S14: calculating a capacitive stability, an inductive stability and a stability of the synchronous generator.

The method according to the invention enables the diagnosis (15, 16) of phase current sensor defects in a system for controlling a synchronous rotary electrical machine of a motor vehicle. According to the invention, the method takes into account the differences (îd, lq) between measurements provided (14) by the sensors, and nominal values of the phase currents (ia, ib, ic) in order to diagnose defects. The differences are calculated (18) in a rotating Park reference frame (17) and are separate from an electromechanical model of the machine. The method detects sensor defects if the differences are substantially non-zero (19) and an offset sensor defect if a residual pulsation (ω res) of the differences is substantially equal to a measured speed (w) of the control system.

An arithmetic device and a motor drive device including the arithmetic device capable of performing high accuracy motor current calculation, include a control unit performing an arithmetic processing including: acquire a duty ratio; calculate a waiting time according to the duty ratio and a waiting coefficient; detect a shunt current value at a detection timing after lapse of the waiting time; acquire, as a zero-cross current value, the shunt current value; calculate an average value using the shunt current values; and calculate an effective current value by correcting the average value using a correction coefficient.

A motor control system includes a motor and a motor control circuitry. The motor includes a rotation axis and a bearing rotatably supporting the rotation axis. The motor control circuitry is configured to control the motor. The motor control circuitry includes a driving time adding circuit configured to add up a driving time of the motor to obtain an accumulated driving time of the motor, a remaining lifetime calculation circuit configured to calculate a remaining lifetime of the bearing based on a lifetime of the bearing and the accumulated driving time, and a warning outputting circuit configured to output warning information when the remaining lifetime is equal to or less than a threshold.