INSULATED POWER SUPPLY APPARATUS FOR POWER CONVERSION APPARATUS

• US 20150078039A1
• Filed: 09/18/2014
• Published: 03/19/2015
• Est. Priority Date: 09/18/2013
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: MIYAUCHI, Syun, MAEBARA, Tsuneo, ASAKO, Yousuke
• Granted Patent: US 9,712,037 B2
• Time in Patent Office: Days
• US Class Current: 363/21.12
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 1/0054 Transistor switching losses periodically suspending operation of switching converter in low power mode H02M1/0035
• CPC Class Codes: H02M 1/08 Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H03K 17/06 Modifications for ensuring a fully conducting state
• CPC Class Codes: H03K 17/08128 in composite switches
• CPC Class Codes: H03K 17/61 using transformer coupling
• CPC Class Codes: H03K 17/691 using transformer coupling
• CPC Class Codes: H03K 2217/0036 Means reducing energy consumption
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

An insulated power supply apparatus is for a power conversion circuit including at least one series connection of an upper arm switching element and a lower arm switching element connected in series to each other. The insulated power supply apparatus includes an upper arm and lower arm transformers for supplying a driving voltage to the upper arm and lower arm switching elements, respectively, and performs control such that the output voltage of a specific one of the secondary coils of the upper arm and lower arm transformers is kept at a target voltage.

Claims

1. An insulated power supply apparatus for at least one power conversion circuit that includes at least one series connection of an upper arm switching element and a lower arm switching element connected in series to each other, comprising:

an upper arm transformer including an upper arm primary coil to be applied with a DC voltage from a DC power source and an upper arm secondary coil for supplying a first driving voltage to the upper arm switching element;

a lower arm transformer including a lower arm primary coil to be applied with the DC voltage from the DC power source and a lower arm secondary coil for applying a second driving voltage to the lower arm switching element;

a voltage detecting section for detecting an output voltage of an object coil which is one of the upper arm and lower arm secondary coils, an output current of the one of the upper arm and lower arm secondary coils being larger than the other of the upper arm and lower arm secondary coils;

a voltage adjustment switching element that applies the DC voltage of the DC power source to the upper arm and lower arm primary coils while being turned on; and

a manipulation section that on/off controls the voltage adjustment switching element in order that the output voltage detected by the voltage detecting section is feedback-controlled to a target voltage.

2. The insulated power supply apparatus according to claim 1, wherein the power conversion circuit includes a plurality of the series connections which are parallel-connected,

the upper arm transformer is provided for each of a plurality of the upper arm switching elements,

the lower arm transformer is provided common to a plurality of the lower arm switching elements,

the lower arm secondary coil is capable of outputting the second driving voltage to the plurality of the lower arm switching elements, and

the object coil is the lower arm secondary coil.

3. The insulated power supply apparatus according to claim 1, wherein

the insulated power supply apparatus is for a plurality of the power conversion circuits each including a plurality of the series connections,

one of the power conversion circuits is a driving power conversion circuit for driving an electric rotating machine as a vehicle driving engine,

the upper arm transformer is provided for each of a plurality of the upper arm switching elements for each of the plurality of the power conversion circuits,

the lower arm transformer is provided common to a plurality of the lower arm switching elements for each of the plurality of the power conversion circuits,

a charging current necessary to turn on each of the upper arm and lower arm switching elements of the driving power conversion circuit is larger than a charging current necessary to turn on each of the upper arm and lower arm switching elements of any power conversion circuit other than the driving power conversion circuit, and

the object coil is the lower arm secondary coil of the lower arm transformer provided for the driving power conversion circuit.

4. The insulated power supply apparatus according to claim 1, further comprising an upper arm drive circuit for driving the upper arm switching element using the first driving voltage supplied from the upper arm secondary coil and a lower arm drive circuit for driving the lower arm switching element using the second driving voltage supplied from the lower arm secondary coil,

the upper arm drive circuit and the lower arm drive circuit being the same in structure.

5. The insulated power supply apparatus according to claim 4, wherein the target voltage is set above a lower limit of an operation guarantee voltage range of the upper arm and lower arm drive circuits.

6. The insulated power supply apparatus according to claim 1, further comprising an upper arm drive circuit for driving the upper arm switching element using the first driving voltage supplied from the upper arm secondary coil, and a lower arm drive circuit for driving the lower arm switching element using the second driving voltage supplied from the lower arm secondary coil,

the upper arm or lower arm drive circuit connected to the upper arm or lower arm secondary coil of the upper arm or lower arm transformer other than the object coil including an overvoltage protection function that forcibly stops supply of the first and second driving voltages to the upper arm and lower arm switching elements by the manipulation section if the first or second driving voltage inputted thereto exceeds a predetermined voltage.

7. The insulated power supply apparatus according to claim 1, wherein the first and second primary coils of the upper arm and lower arm transformers are connected in parallel to each other as a parallel connection, and the voltage adjustment switching element forms a closed circuit including the DC power source, the parallel connection and the voltage adjustment switching element.

8. The insulated power supply apparatus according to claim 1, wherein the upper arm or lower arm transformer including the object coil includes a voltage detecting coil, and the voltage detecting section detects an output voltage of the voltage detecting coil as the output of the object coil.

9. The insulated power supply apparatus according to claim 1, wherein each of the first and second primary coils and the first and second secondary coils is insulation-coated, and is wound on a bobbin fitted to a core.