Converter control device

• US 9,024,598 B2
• Filed: 06/22/2009
• Issued: 05/05/2015
• Est. Priority Date: 06/22/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hasegawa, Takahiko, Kitamura, Nobuyuki, Manabe, Kota, Umehara, Takahiro
• Primary Examiner(s): Laxton, Gary L
• Assistant Examiner(s): Moody, Kyle J
• Application Number:
  US13/379,917
• Publication Number:
  US 20120098507A1
• Time in Patent Office: 2,143 Days
• Field of Search: 323/271, 323/272, 323/225, 361/87, 361/93.9, 361/93.1
• US Class Current: 323/272
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 1/34 Snubber circuits

Abstract

Provided is a converter control device which detects an on-failure of an auxiliary switch constituting an auxiliary circuit of a soft switching converter and can prevent element failures. A current sensor for detecting the current flowing in a coil is provided between a fuel cell and the. A controller sequentially detects current by use of the current sensor and makes a judgment as to whether or not the detected current has exceeded an overcurrent threshold value stored in a memory (not shown). When the controller judges that the current has exceeded the overcurrent threshold value, the controller judges that a second switching element has an on-failure, and performs a fail-safe operation by stopping the driving of a converter (for example, a U-phase converter) of an auxiliary circuit provided with this second switching element.

Claims

1. A converter control device of a soft switching converter provided with a main booster circuit and an auxiliary circuit, which controls output voltage of a fuel cell, comprising:

a current sensor which detects current flowing in a main coil constituting the main booster circuit;

a controller programmed to perform a judgment process which judges that an auxiliary switch constituting the auxiliary circuit has an on-failure when the current detected by the current sensor exceeds a set overcurrent threshold value and programmed to perform a fail-safe operation which stops operation of the main booster circuit when it is judged that the auxiliary switch has the on-failure, wherein the main booster circuit has;

the main coil, one end of which is connected to a terminal on a high-potential side of the fuel cell;

a main switch which performs switching, one end of which is connected to the other end of the main coil and the other end of which is connected to a terminal on a low-potential side of the fuel cell;

a first diode whose anode is connected to the other end of the main coil; and

a smoothing capacitor provided between the cathode of the first diode and the other end of the main switch, and

wherein the auxiliary circuit has;

a first series-connected body including a second diode and a snubber capacitor which are connected in parallel to the main switch and connected to the other end of the main coil and a terminal on the low-potential side of the fuel cell; and

a second series-connected body including a third diode, an auxiliary coil and the auxiliary switch which are connected between a connecting portion between the second diode and the snubber capacitor and the one end of the main coil.