Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Yoshiyuki Hamanaka

Tsuneo Maebara

Ryotaro Miura

Koichi Sakata

Junichi Fukuta

Tomotaka Suzuki

Kazunori Watanabe

Yusuke Shindo

Akito Itou

Junichi Nagata

Takeyasu Komatsu

Takahiro Iwamura

Syun Miyauchi

Tomoyuki Muraho

Noriyuki Takagi

Yasunari Tanimura

Masatoshi Taguchi

Junichi Fukita

A power converter includes a backup power source Eb provided separately from a power source Es and designed to supply power during a discharge period, and a discharging driver Mb that turns on/off an upper-arm (one) switching element in series-connected switching elements Qu and Qd based on a drive signal that has at least one of a voltage and a frequency, and drives a lower-arm (the other) switching element Qd such that it is always on, the at least one of the voltage and the frequency of the drive signal being within a predetermined range lower than a drive signal outputted from a normal driver Mu, Md.

Power converter

An inverter for driving a motor generator has series connection units, each of which has two switching elements, connected in series, in high and low voltage sides, respectively. A drive unit is arranged for each switching element. A gate of the switching element is connected to an emitter thereof through a first cutoff resistance and a first cutoff switching element in the drive unit. The gate of the switching element is also connected to the emitter thereof through a second cutoff resistance and a second cutoff switching element in the drive unit. A resistance value of the first cutoff resistance is higher than a resistance value of the second cutoff resistance. A software cutoff process is performed when the switching element is in a completely turned-on state so that the first cutoff switching element is turned on and the second cutoff switching element is turned off.

Drive unit for switching element

In a driver having a reference point with a reference potential for driving a target switching element having an on-off control terminal, a charging path electrically connects the on-off control terminal of the target switching element and a driving power source for charging the on-off control terminal of the target switching element. A bypass path electrically connects the on-off control terminal of the target switching element and the driving power source. A storage has a first conductive end electrically connected to the bypass path and a second conductive end electrically connected to the reference point of the target switching element, and is configured for storing therein charge sent through the bypass path.

Driver for target switching element and control system for machine using the same

A temperature measuring apparatus is provided which includes a sensor assembly made up of sensing devices which are connected together to produce an output signal correlated with the temperature of a target object. The temperature measuring apparatus determines the number of the sensing devices of the sensor assembly and corrects the output signal so as to compensate for an error in determining the temperature of the target object which depends upon the number of the sensing devices.

Temperature measuring apparatus with sensor assembly of sensing devices connected together

A drive circuit for a switching element includes a constant-current control unit and a restriction unit. The constant-current control unit performs a constant-current control for charging an open/close control terminal of a switching element to be driven which is a voltage-controlled switching element with electric charge for turning on the switching element. The restriction unit restricts, to a reference voltage, a voltage between the open/close control terminal and a first end of a pair of ends of a current flow path of the switching element for a predetermined period following a start of the constant-current control within a charging process period during which the open/close control terminal is charged with the electric charge such that the switching element is turned on.

Drive circuit for switching element

A discharge controller carries out discharge control by determining a voltage to be applied to a conduction control terminal of each of switching elements such that a current in a non-saturation region of one of the switching elements is lower than a current in a non-saturation region of the other thereof, and applying the voltage to the conduction control terminal of each switching element with an opening-closing member opening an electrical path to turn on the switching elements, resulting in short-circuit of both electrodes of a capacitor so that a discharge current is outputted from the capacitor based on the discharge control. A manipulator manipulates, based on a value of the discharge current, how to apply the voltage to the conduction control terminal of the one of the switching elements, thus controlling an amount of heat to be generated in the one of the switching elements.

Discharge control apparatus for power converting system with capacitor

A drive circuit is used for driving a switching element. The drive circuit includes a detection unit and an integrated circuit. The detection unit detects a state of a controlled switching element and outputs a voltage signal corresponding to a detection result of the state. The integrated circuit receives the voltage signal via an input terminal for the detection result and controls the switching element based on the received voltage signal. The input terminal includes at least two input terminals that are connected to each other so as to receive the same voltage signal from the detection unit.

In an error correction device, a frame generation section receives pulse signals as temperature information of a power switching element transmitted from a PWM comparator. The frame generation section sets a first correction pulse signal, a second correction pulse signal and the temperature information sequentially into each frame. A pulse width of the first correction pulse signal corresponds to a pulse width when a time ratio thereof becomes 100%. A pulse width of the second correction pulse signal corresponds to a pulse width when a time ratio thereof becomes 50%. A microcomputer receives the temperature information through a photocoupler and corrects the received temperature information. The microcomputer calculates a temperature detection value of the power switching element on the basis of the corrected temperature information.

Error correction device

A failure information transmission apparatus includes a transmission circuit and a reception circuit. The transmission circuit transmits a plurality of pieces of failure information related to a plurality of failures as pulse signals different from one another via the same transmission path. The reception circuit receives the pulse signals transmitted by the transmission circuit via the same transmission path and identifies the failure information based on the pulse signal received. If the plurality of failures occurs at the same time, the transmission circuit transmits preferentially transmits failure information with higher priority of transmission.

Failure information transmission apparatus

A first-path connects an input-terminal and an output-terminal of a high-potential-side switching-element and includes a high-potential-side rectifying-device and a high-potential-side passive-element. A second-path connects the output-terminal of the high-potential-side switching-element and the output-terminal of a low-potential-side switching-element and includes a low-potential-side rectifying-device and a low-potential-side passive-element. A high-potential-side applying-unit applies voltage to a connecting point between the high-potential-side rectifying-device and the high-potential-side passive-element. A high-potential-side determining-unit determines that an overcurrent is flowing between the input-terminal and the output-terminal of the high-potential-side switching-element by using a first-value. A limiting-unit limits a current between the low-potential-side rectifying-device and the output-terminal of the high-potential-side switching-element if the overcurrent is flowing. A low-potential-side applying-unit applies voltage to a connecting point between the low-potential-side rectifying-device and the low-potential-side passive-element. A low-potential-side determining-unit determines that an overcurrent is flowing between the input-terminal and the output-terminal of the high-potential-side or low-potential-side switching element by using a second-value.

Drive circuit for switching elements

A transmission circuit transmits a header pulse signal which has signal length being equal to or more than twice as long as reference time, pulse period having predetermined ratio thereof to the signal length, and pulse stop period being successive and longer than the reference time via transmission path. The transmission circuit subsequently and successively transmits a plurality of data pulse signals which have signal length being the same as the reference time, pulse period having predetermined ratio thereof to the signal length associated with data, and pulse stop period being located before and after the pulse period via the transmission path. A reception circuit receives pulse signals via the transmission path, detects the header pulse signal based on the pulse stop period of the received pulse signal, and obtains a plurality of pieces of data based on the pulse period of pulse signals following the header pulse signal.

Information transmission apparatus

In a driver, a charging module stores negative charge on the gate of a switching element via a normal electrical path to charge the switching element upon a drive signal representing change of an on state to an off state. This shifts the on state of the switching element to the off state. An adjusting module changes a value of a parameter correlating with a charging rate of the switching element through the normal electrical path as a function of an input signal to the driver. The input signal represents a current flowing through the conductive path, a voltage across both ends of the conductive path, or a voltage at the gate. A disabling module disables the adjusting module from changing the value of the parameter if the drive signal represents the on state of the switching element.

Driver for switching element and control system for rotary machine using the same

A motor control apparatus includes an inverter, a smoothing capacitor, power-converting drivers, a power-converting power supply circuit, and discharging drivers. The inverter includes switching circuits comprised of series-connected two IGBTs. The power-converting drivers apply an output voltage of the power-converting power supply circuit to the switching circuits to drive them, thus performing power conversion. The discharging drivers simultaneously turn on IGBTs of the switching circuit to discharge the smoothing capacitor when the output voltage of the power-converting power supply circuit is equal to or lower than a threshold. This prevents discharging of the smoothing capacitor during power converting operations.

The drive circuit is for turning on and off a switching element having an open/close control terminal, an input terminal and an output terminal by moving electrical charge in the open/close control terminal in accordance with an on-manipulation command and an off-manipulation command received from outside. The drive circuit includes an active gate control means for changing a moving speed of the electrical charge midway between when movement of the electrical charge is started and when the movement is completed, and a determination means for making at least one of a determination on a change timing to change the moving speed and a determination on whether or not a change of the moving speed by the active gate control means should be made.

In a drive unit for a reverse-conducting switching element which is a driven switching element, a process to transfer electric charges to a conductive control terminal of the driven switching element is performed on the basis of a turn-on command or a turn-off command, thereby turning on and off the driven switching element. A transfer rate of the electric charges is changed in a period from when the transfer of the electric charges to the conductive control terminal is started until when it is completed. While judged that forward current flows in a free-wheel diode, the electric charges are inhibited from being charged to the conduction control terminal which corresponds to the free-wheel diode in which the forward current is judged to flow. While the electric charges are inhibited from being charged to the conductive control terminal, a change of the transfer rate is disabled.

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Kariya, Japan

Yoshiyuki Hamanaka