Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi, Ltd.

Masayuki Hirota

Kazuhiro Watanabe

Satoshi Ibori

Masahiro Hiraga

Tomoya Kamezawa

Yutaka Maeno

Tooru Nakajima

Kinya Nakatsu

Yasushi Sasaki

Yusuke Arao

Jiangming Mao

Naoki Takata

Kazuyuki Fukushima

Tetsuya Kimura

Yoshihiro Uchino

Mingxi Huang

Koji Hamano

Hidenori Sugino

Tadashi Yamazaki

Kinya Hitachi Ltd Nakatsu

Jiang Ming Mao

A power transducer is downsized by reducing the size of a power source board and highly reliable. The power source board is provided in the power transducer and for a large-current circuit. The power transducer includes a power semiconductor module having lead terminals. Of the lead terminals provided for the power semiconductor module and connected with the main circuit board, predetermined one or ones of the lead terminals is or are connected with the main circuit board in the vicinity of a main circuit terminal stage and at a position or positions lower than the main circuit terminal stage. Alternatively, predetermined one or ones of the lead terminals is or are connected with the main circuit board at a position or positions lower than a position at which the main circuit terminal stage is provided.

Power transducer

A temperature detection method for a semiconductor device and a power conversion apparatus are disclosed. A temperature detection device is used to detect the temperature for thermal protection of a power semiconductor device. The temperature detection device is placed in the proximity of a component having the power semiconductor device packaged therein, and either an emitter terminal or a collector terminal of the power semiconductor device. Since the temperature detection device is mounted on a circuit board, it does not require insulation from a cooling fin on which the power semiconductor device is mounted and lead wires can be eliminated.

Temperature detection method of semiconductor device and power conversion apparatus

In the present invention, miniaturization of an electric power conversion system is made possible while the reduction of a rise in temperature is achieved through a cooling operation by a cooling fan. The electric power conversion system is provided with a casing for covering cooling fins for cooling power semiconductors, a main circuit board having a driver circuit for driving the power semiconductors, and a cover for covering up the main circuit board. The system includes a first airflow hole provided at a part of the main circuit board, on the upper side of an air-intake provided in the cover, and a second airflow hole provided on the lower side of the first airflow hole, and on the lower side of the cooling fins, wherein air from the second airflow hole is driven to the cooling fins by a cooling fan.

Electric power conversion system

For applications in a facility where a power conversion apparatus is frequently started and stopped, a power conversion apparatus and a power cycle longevity estimation method are provided which improve an ease of use of the facility. The power conversion apparatus comprises power conversion circuits to supply ac power of variable voltage and variable frequency, a detection circuit to detect a temperature of the power semiconductor in the power conversion circuits, and a computation device to calculate a power cycle longevity of the power semiconductor based on a maximum temperature rise detected by the detection circuit.

Power conversion apparatus and method of estimating power cycle life

The invention provides a technique and a product in which for a frequency converter supplying electric power to, for example, a motor, a downsizing, lightening or the like of the frequency converter is realized while providing a filter apparatus reducing electromagnetic noises and the like. The filter apparatus reducing electromagnetic noises and the like is provided near a main circuit terminal board of the frequency converter, and the filter apparatus is connected directly to a main circuit terminal as a wiring drawing portion of the frequency converter. Part of a housing of the frequency converter and part of a filter housing are fitted to each other to fix the filter housing to the frequency converter.

Filter apparatus and frequency converter to which the filter apparatus is connected

A frequency converter in which the inductance is reduced by enlarging the forms of bus bars which connect a P phase, an N phase of an inverter part and a positive electrode or a negative electrode of smoothing capacitors and the form of a wiring bus bar which connects an intermediate layer of capacitors which are connected in series to enlarge areas where they overlap each other, and by making currents flow in the opposite directions to each other.

AC/DC/AC converter with reduced inductance in the DC filter capacitors

The present invention provides an electric power converter in which a tip portion of a cooling fin on an air flow inlet side is limited to flow a large quantity of air around a connection portion, where the fin efficiency is high, of a base surface of the cooling fin and the fin so that the cooling efficiency of the cooling fin can be improved. By providing the limiting member, air or atmosphere flowing into the cooling fin is directed to flow toward the fin near the base surface. Further, by providing the limiting member, an area of a portion from which the air or atmosphere flows into the cooling fin is also limited so that the velocity of the air or atmosphere flow becomes high. By these functions and the like, the cooling efficiency of the cooling fin can be increased as compared to the prior art.

Electric power converter

An object of the present invention is to lower the voltage applied to the starting resistor of the starting circuit in a switching power supply circuit to reduce the power loss especially when the receiving voltage is high and thereby provide a small and inexpensive switching power supply circuit. According to the present invention, a switching power supply circuit comprises: a DC voltage section having two or more capacitors connected in series; and a PWM control circuit for receiving DC power supply from the DC voltage section and performing switching control on a primary side of a transformer in order for the switching power supply circuit to output a DC voltage of different voltage specifications; wherein the starting resistor for the PWM control circuit is connected to a connection point of the capacitors.

Switching power supply circuit and frequency converter

A frequency converter includes a circuit substrate, a housing that covers at least the circuit substrate, a radiating section in which gases at an intake face are exhausted from an exhaust face so as to radiate heat, a fan provided on the exhaust face of the radiating section, and a guide provided on the housing to direct gases around the circuit substrate toward the intake face.

Frequency converter

An electric circuit module comprising: an electric device comprising an electric circuit to serve for passage and interruption of electric current, a packing material packing the electric circuit and a plurality of wiring members to electrically connect the electric circuit with an external circuit; and a heat sink to radiate heat from the electric device. The electric circuit module includes a fixture to fix the heat sink and the electric device together so that a heat radiating surface of the electric device comes into contact with the heat sink. The fixture is formed with a recess to accommodate therein a part of the electric device so that the heat radiating surface of the electric device is exposed from the fixture. When the electric device is fixed to the heat sink by the fixture, the heat radiating surface comes into contact with the heat sink.

Electric circuit module

Measures are provided to prevent temperature rise caused by that heat generated from power elements, which is radiated inside a housing. In a housing comprising a radiating section and a cooling fan, a guide is provided on a part of the housing to be made longer a predetermined value than the radiating section. When the cooling fan performs forced cooling through the guide, gases heated by a substrate that generates much heat are prevented from flowing onto a substrate that generates comparatively less heat, to heat the substrate that generates comparatively less heat. Therefore, for example, the substrate that generates much heat is arranged in a position nearer to the cooling fan than the substrate that generates comparatively less heat. Alternatively, the substrate that generates much heat is arranged in a position nearer to the intake face than the substrate that generates comparatively less heat. By providing the guide on the housing, an existing fan can radiate heat from the substrate that generates much heat, the substrate that generates comparatively less heat, etc., thereby enabling reduction in temperature rise.

A low noise, compact and low cost electric power converter employing a compact common mode transformer, and incorporating a line filter can reduce a leakage current, and can maintain predetermined leakage current reduction effect even if installation condition of the electric power converter or a characteristics of a semiconductor switching element is varied. The electric power converter including a capacitor, a first electrode, a second electrode, a first magnetic body, on which the first electrode and the second electrode are wound to form an LC composite element, connecting electrodes electrically connected to respective of both ends of the first and second electrodes, a second magnetic body for interlinking both ends of the first magnetic body, a coil wound around the second magnetic body in the same winding direction as the first and second electrodes wound around the first magnetic body and a resistor for shorting the output of the coil.

Growing community of inventors

Narashino, Japan

Masayuki Hirota