Patent application number | Description | Published |
20100026220 | Driving apparatus for multi-phase AC synchronous motor - An inverter control circuit controls transistors based on comparison of a voltage command wave with a carrier wave, when a magnitude of a voltage vector is equal to or less than a peak value of the carrier wave. The voltage command wave is a wave, which is offset to a maximum value side from a reference potential of the carrier wave so that a maximum value of the voltage command wave equals a peak value of the carrier wave. The inverter control circuit makes an on-period of the transistor on a positive bus side longer than that of the transistor on a negative bus side by using the command voltage. The amount of electricity charged in a capacitor is reduced in comparison with a case in which the voltage command wave is used. Thus, thermal loss of a stator coil and a diode on the positive bus side is reduced. | 02-04-2010 |
20100231153 | Driving apparatus for three-phase AC synchronous motor - In a driving apparatus for a three-phase synchronous motor, in which a battery is connected between a neutral point of a stator coil and a negative-pole bus, a control circuit acquires three-phase AC currents. The control circuit checks whether a neutral-point electric current is contained in an electric current detected by an electric current detecting section. Based on the check result, the control circuit checks whether electric current values for three-phases containing the neutral-point electric current are set together or electric current values for three-phases excluding the neutral-point electric current are set together to acquire the three-phase AC currents for driving the motor. | 09-16-2010 |
20110031922 | ELECTRIC MOTOR DRIVE DEVICE, CONTROL METHOD OF ELECTRIC MOTOR DRIVE DEVICE, AND ELECTRICALLY DRIVEN DEVICE - An electric motor drive device has an inverter adjusting the voltage applied to an AC electric motor so as to drive the AC electric motor, a capacitor which is charged by a current supplied from a DC power supply supplying DC voltage between a neutral point at which a plurality of coils of the AC electric motor are connected and a positive rail or negative rail of an inverter and passing through the inverter, and a control circuit controlling the inverter so that the AC electric motor turns at a designated speed. Further, the control circuit selectively uses field weakening control and voltage boosting control for control of the inverter according to the conditions of the induced voltage generated at the AC electric motor, DC power supply, and voltage of the capacitor. | 02-10-2011 |
20110050136 | Driving apparatus for a vehicle-mounted electric motor - An inverter circuit for a motor outputs three-phase AC currents, which are outputted from common connection points to stator coils, based on output voltage of a DC power source and a power supply capacitor by a switching operation of transistors. An inverter control circuit determines that a system main relay is turned off, upon receiving a main relay-off signal from an electronic control unit. The inverter control circuit turns on the low-side transistors, while turning off the high-side transistors. A discharge current flows from the positive electrode to the negative electrode of the power supply capacitor through the stator coil and the low-side transistors, so that electric charge stored in the power supply capacitor is discharged. | 03-03-2011 |
20120292985 | VEHICULAR ELECTRIC SYSTEM - In a vehicular electric system, a first motor driver device and a second motor driver device are connected in parallel to a DC power source. A first capacitor is provided to suppress variations in a voltage developed between the DC power source and the first motor driver device. A second capacitor is provided to suppress variations in a voltage developed between the DC power source and a second motor driver device. A resistor is connected in series to the second capacitor. A filter circuit is thus suppressed form resonance even when a frequency included in a ripple current outputted from an inverter circuit of the first motor driver device overlaps a resonance frequency of the filter circuit. | 11-22-2012 |
20150155804 | MOTOR DRIVING DEVICE - A motor driving device includes an inverter circuit having switching elements; and a control device controlling the switching of the switching elements. The control device sets a carrier frequency to f1 when a two-phase modulation scheme is selected, and sets the carrier frequency to f0, which is half of the carrier frequency f1, when a three-phase modulation scheme is selected. Thereby, the frequency of the secondary component of a current flowing in a filter circuit of when selecting the three-phase modulation scheme may be deviated from the resonance frequency of the filter circuit. Accordingly, the current ripple generated in the filter circuit may be reduced even when selectively switching the modulation scheme for the PWM modulation among a plurality of modulation schemes. | 06-04-2015 |
20150292511 | HIGH VOLTAGE ELECTRIC DEVICE AND ELECTRIC COMPRESSOR - A high voltage electric device attached to a cooling unit includes heating components, an electric circuit board, a case, and an insulating member. The heating components are used at high voltage and are different in size. The heating components are fixed via lead wires respectively to the electric circuit board. The case accommodates the heating components and the electric circuit board. The insulating member seals the heating components and the electric circuit board in the case. An outermost peripheral surface of the insulating member on the cooling unit-side cooled by refrigerant is referred to as a reference surface. Respective shortest distances from the reference surface to the heating components are the same as each other. An electric compressor includes the high voltage electric device, an electric motor that is operated by electric power supplied by the high voltage electric device, and a compression mechanism that is driven by the electric motor and is applied to a refrigeration cycle. The cooling unit is cooled by the refrigerant drawn into the compression mechanism. | 10-15-2015 |
20150295532 | ELECTRIC COMPRESSOR - A controller for an electric compressor sets a temperature rise region A, a temperature drop region B, and a steady region C from change in temperature of switching elements, and sets a carrier frequency for each of the set regions. In the region A, the carrier frequency is changed according to the element temperature so that the carrier frequency decreases with increase of the element temperature at startup of a motor. In the region B and the region C, the carrier frequency is changed according to the number of revolutions of a compression mechanism, so that the carrier frequency decreases with increase of the number of revolutions of the compression mechanism, regardless of the element temperature. | 10-15-2015 |