Power converter

Abstract

To provide a power conversion device capable of more appropriately detecting a failure of four switching elements connected in full-bridge.SOLUTION: A power conversion device comprises: a full-bridge circuit having four switching elements connected in full-bridge; and a control device that controls the operation of the full-bridge circuit. The full-bridge circuit includes four voltage detectors that detect a voltage between a pair of main terminals of each of the four switching elements. The control device detects a failure of the four switching elements when at least one of a situation where the voltages between the pairs of main terminals of two switching elements on high side from the four switching elements have been in the same state for a predetermined period of time or longer and a situation where the voltages between the pairs of main terminals of the two switching elements on low side from the four switching elements have been in the same state for the predetermined time or longer is satisfied on the basis of detection results of the four voltage detectors.SELECTED DRAWING: Figure 1

Claims

1. A full-bridge circuit having four switching elements connected in a full-bridge configuration, which performs power conversion by switching the four switching elements, A control device that controls the operation of the full-bridge circuit, Equipped with, Each of the four switching elements has a pair of main terminals and a control terminal. The full-bridge circuit has four voltage detectors, each corresponding to one of the four switching elements, which detect the voltage between the pair of main terminals of each of the four switching elements. The control device is a power converter that detects a failure in one of the four switching elements when, based on the detection results of the four voltage detectors, at least one of the following conditions is met: the voltage between the pair of main terminals of the two high-side switching elements of the four switching elements remains the same for a predetermined time or longer, and the voltage between the pair of main terminals of the two low-side switching elements of the four switching elements remains the same for a predetermined time or longer.

2. The power conversion device according to claim 1, wherein the control device detects, based on the detection results of the four voltage detectors, that a failure has occurred in one of the four switching elements when at least one of the following conditions is met: the voltage between the pair of main terminals of the two high-side switching elements of the four switching elements is above a predetermined voltage for a predetermined time or longer, and the voltage between the pair of main terminals of the two low-side switching elements of the four switching elements is above the predetermined voltage for a predetermined time or longer.

3. The power conversion device according to claim 1, wherein the control device detects, based on the detection results of the four voltage detectors, that a failure has occurred in one of the four switching elements when at least one of the following conditions is met: the voltage between the pair of main terminals of the two high-side switching elements of the four switching elements is less than a predetermined voltage for a predetermined time or more, and the voltage between the pair of main terminals of the two low-side switching elements of the four switching elements is less than the predetermined voltage for a predetermined time or more.

4. The system comprises two of the full-bridge circuits connected via a transformer, The power conversion device according to claim 1, wherein the control device detects that a failure has occurred in any of the four switching elements of one of the full-bridge circuits based on the detection results of the four voltage detectors of one of the full-bridge circuits, and detects that a failure has occurred in any of the four switching elements of the other full-bridge circuit based on the detection results of the four voltage detectors of the other full-bridge circuit.

5. The control device is By transmitting a control signal only to one of the full-bridge circuits without transmitting a control signal to the other full-bridge circuit, the conversion of power from one full-bridge circuit to the other full-bridge circuit is controlled. By transmitting a control signal only to the other full-bridge circuit without transmitting a control signal to the other full-bridge circuit, the conversion of power from the other full-bridge circuit to the one full-bridge circuit is controlled. The power conversion device according to claim 4, which detects a failure in any of the four switching elements of each of the two full-bridge circuits in each of the bidirectional power conversions, in the direction from one full-bridge circuit to the other full-bridge circuit and in the direction from the other full-bridge circuit to the first full-bridge circuit.

Images