Abstract: In the motor driving system, a unit to predict the separation of the wire is built into the power semiconductor module thereby to predict that the time of separation of the wire is approaching before the actual separation of the wire. Thus, the time to replace the power semiconductor module used for power devices such as the motor driving system is clarified to prevent an operation failure of the motor driving system from occurring. The power semiconductor module (1) has a power semiconductor chip (2) mounted thereon, and the power semiconductor chip (2) includes a main circuit wire (4) and a dummy wire (5) connected to the electrode (3) of the power semiconductor. The dummy wire is set to a lower connection strength than the main circuit wire.

Abstract: In a control apparatus, a “characteristic value calculation” block calculates a characteristic value (such as amplitude value, offset value, or waveform distortion for each phase of two-phase sinusoidal signals optically input from an encoder, or phase difference between the two phase signals) for each of the two-phase sinusoidal signals, and an “alarm detection” block checks the presence or absence of an excursion outside a predetermined allowable range and, if such an excursion is detected, produces an alarm indication or the like. Each time the “present characteristic value” is input, a “characteristic value comparison” block compares it with “previous characteristic values”, and analyzes the result of the comparison. That is, the difference between the present value and each previous data is calculated, and the largest amount of variation (with plus or minus sign) is obtained; if this amount is larger than a predetermined value, a signal indicating an “imminent failure” is output.

Abstract: A magnetic flux produced by the current of a motor is detected by means of a Hall element, and an infinitesimal current proportional to the actual current of the motor is outputted. The outputted infinitesimal current is run through a resistor, and a potential difference across the resistor is detected by a ?? modulator circuit. The motor is subjected to feedback control based on the potential difference detected by the ?? modulator circuit.

Abstract: A motor driver capable of detecting the insulation deterioration of a motor easily and inexpensively is disclosed. The voltage supplied from an AC power supply (1) is rectified by a first rectifying circuit (D1 to D6) and smoothed by a capacitor (C) in a power supply unit (6). The output voltage of the power supply unit (6) is converted into an AC voltage of a frequency and a motor (M) is driven by a motor drive amplifier (8). Elements (R1, C2, R11, C21) are connected between at least one of the positive electrode (4) and the negative electrode (5) of the output line (4, 5) of the power supply unit (6) and the ground (G2, G4). An insulation deterioration circuit (10, 11, 12) detects at least one of the voltage between the elements and the current flowing through the elements.

Abstract: An electric motor (1) is driven by an inverter amplifier (2) through a cable (5). An absorber (3) is built in the electric motor (1) to suppress and absorb a surge voltage generated due to the surge impedance mismatch between the cable (5) and the electric motor (1) as well as a high-frequency noise generated due to the switching operation of a switching element in the inverter amplifier. The absorber (3) is made up of a plurality of conductors, each of which has a predetermined length and is covered with an insulating material. The conductors are connected to the input terminals (4a, 4b, 4c) of the electric motor (1), respectively. The forward end of each conductor of the absorber (3) is either open or connected to one or more other conductors through a member of a high impedance. The surge voltage and the high-frequency noise are suppressed and absorbed by the absorber.

Abstract: An inverter apparatus is provided with first and second current detectors for detecting the current of two arbitrary phases and further with first and second A/D converters, and they are integrated into one unit. It furthermore stores, in a storage device, a compensation value for compensating for an unbalance between gains of the first current detector and the first A/D converter, and gains of the second current detector and the second A/D converter. By multiplying the detected current value of either one of the detected phases by this compensation value, it equalizes the current feedback gains for both phases.

Abstract: A motor driving apparatus capable of drivingly controlling a plurality of inverter units with a single motor driving command from a motor control unit, and thereby control a large-capacity motor or the like. The motor control unit sends out a single motor driving command (torque command) S. An intermediary unit obtains motor driving commands S×A1 to S×A4 for the inverter units by multiplying the motor driving command S by each of coefficients A1 to A4 set in advance. The inverter units are fed with the motor driving commands S×A1 to S×A4 individually and drive a single motor. Since the motor is driven by the total current supplied by the inverter units, the motor can generate a large torque. The motor control unit only needs to generate a single motor driving command S, and hence only needs to operate a single processing part. Hence, the motor control unit can generate and send out motor driving commands for other motors to drive them.

Abstract: A magnetic flux produced by the current of a motor is detected by means of a Hall element, and an infinitesimal current proportional to the actual current of the motor is outputted. The outputted infinitesimal current is run through a resistor, and a potential difference across the resistor is detected by a &Dgr;&Sgr; modulator circuit. The motor is subjected to feedback control based on the potential difference detected by the &Dgr;&Sgr; modulator circuit.

Abstract: A circuit system that includes a sensor circuit for a sensor that detects the state of a motor is provided in an inverter unit for driving the motor. A 0V of the circuit system is connected with a shield braid of a shielded cable that connects the sensor circuit and the sensor. Further, the shield braid of the shielded cable is connected to an earth plate.

Abstract: A protecting method and apparatus for a regenerative resistor in which a regenerative resistor is satisfactorily protected from a thermal breakage caused by an over-regeneration by combining a projection of the regenerative resistor by a thermostat and a protection of the regenerative resistor by an analog simulation circuit and by coordinating protective regions of these two protections. The heat-responsive switch (2) stops power supply to a DC link (10) when the temperature of the regenerative resistor is increased to a predetermined value or greater value. The analog simulation circuit (1) is provided with a charge-discharge circuit to be charged and discharged in response to a regenerative pulse signal from a level detector (7), estimates the quantity of heat accumulated in the regenerative resistor (5) by means of the charge-discharge circuit, and stops power supply to the DC link (10) when a predetermined threshold value is exceeded by the estimated value.