Power electronics equipments

Abstract

Power electronics equipment includes air-cored insulating transformers inserted between a control circuit grounded to a vehicle body and an upper arm biased at a high voltage, and air-cored insulating transformers between the control circuit grounded to the vehicle body and the lower arm biased at a high voltage. Each of the air-cored insulating transformers includes a primary winding and a secondary facing to each other. The power electronics equipment facilitates improving resistance against hazardous environments, suppressing the deterioration by aging, reducing the adverse effects of noise caused by external magnetic flux, and transmitting and receiving signals while insulating the low and high voltage sides electrically from each other.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram schematically showing an intelligent power module for a step-up and step-down converter, to which a power electronics equipment according to a first embodiment of the invention is applied.

FIG. 2( a) is a cross sectional view schematically showing the insulating transformer according to a first embodiment of the invention.

FIG. 2( b) is a top plan view of the insulating transformer shown in FIG. 2(a).

FIG. 3 is a drawing illustrating the magnetic field generated by the current flowing through a rounding coil.

FIGS. 4( a) through 4(l) are cross sectional views describing the manufacturing steps for manufacturing an insulating transformer according to a second embodiment of the invention.

FIGS. 5( a) through 5(h) are other cross sectional views describing the other manufacturing steps for manufacturing the insulating transformer according to the second embodiment of the invention.

FIG. 6 is a cross sectional view showing the mounted state of an intelligent power module for the step-up and step-down converter according to a third embodiment of the invention.

FIG. 7 is a block diagram of a signal transmission circuit that uses an insulating transformer for signal transmission according to a fourth embodiment of the invention.

FIG. 8 is a block diagram of a signal transmission circuit that uses an insulating transformer for signal transmission according to a fifth embodiment of the invention.

FIG. 9 is a block diagram of a signal transmission circuit that uses an insulating transformer for signal transmission according to a sixth embodiment of the invention.

FIG. 10 is a block diagram of a signal transmission circuit that uses insulating transformers for signal transmission according to a seventh embodiment of the invention.

FIG. 11 is a block diagram schematically showing a vehicle driving system that employs a conventional step-up and step-down converter.

FIG. 12 is a block circuit diagram of the step-up and step-down converter shown in FIG. 11.

FIG. 13 is a wave chart describing the waveform of the current flowing through the reactor shown in FIG. 12 in the boosting operation.

FIG. 14 is a block diagram schematically showing an intelligent power module for the conventional step-up and step-down converter.

FIG. 15 is a block diagram schematically showing the peripheral circuit of a photocoupler.

FIG. 16 is a curve describing the temperature dependence of the current transfer ratio of the photocoupler.

FIG. 17 is a curve describing the deterioration by aging of the current transfer ratio of the photocoupler.

FIG. 18 is a top plan view schematically showing a conventional insulating transformer for signal transmission.

FIG. 19 is a block diagram of a signal transmission circuit using a conventional insulating transformer for signal transmission.

Claims

1. A power electronics equipment comprising: a pair of switching devices connected in series to each other and having one switching device working for an upper arm and the other switching device working for a lower arm, said switching devices having control terminals and being operable to make a current flowing to a load or to interrupt the current flowing to the load;a control circuit for generating control signals directing conduction and non-conduction of the switching devices;driver circuits for driving the control terminals of the respective switching devices based on the control signals; andinsulating transformers disposed to correspond to the switching devices to insulate the control circuit and the driver circuits from each other, each of the insulating transformers comprising a primary winding and a secondary winding facing each other.

2. The power electronics equipment according to claim 1, wherein the primary winding and the secondary winding are laminated one on the other using an insulator layer.

3. The power electronics equipment according to claim 1, wherein the insulating transformers are micro-machined insulating transformers.

4. The power electronics equipment according to claims 1, wherein the insulating transformers are air-cored insulating transformers.

5. The power electronics equipment according to claim 1, wherein each of the switching devices comprises an insulated gate bipolar transistor.

6. The power electronics equipment according to claim 1, wherein the control circuit comprises at least one of a logic circuit and a central processing circuit.

7. The power electronics equipment according to claim 1, wherein a plurality of said insulating transformers is disposed between the control circuit and each of the switching devices.

8. The power electronics equipment according to claim 7, wherein the signals transmitted between the control circuit and the switching devices comprise control signals operable to control the respective switching devices and state signals indicating states of the respective switching devices.

9. The power electronics equipment according to claim 8, further comprising at least one self diagnosis circuit disposed on a side of the switching device, the self diagnosis circuit generating the state signals of the respective switching devices, said control circuit being operable to stop the control signals or change frequency of the control signals in response to the state signals of the respective switching devices.

10. The power electronics equipment according to claim 1, further comprising a module having a circuit board, on which the insulating transformers are mounted, the switching devices being arranged therein.

11. The power electronics equipment according to claim 1, wherein the insulating transformers are mounted on a package.

12. The power electronics equipment according to claim 1, wherein the insulating transformers transmitting signals for the upper arm and the insulating transformers transmitting signals for the lower arm are mounted on a package.

13. The power electronics equipment according to claim 1, further comprising: a primary side circuit operable to make a pulse current flow through the primary windings of the insulating transformers, the pulse current corresponding to rising and falling edges of transmitted signal transmitted via the relevant insulating transformer, anda secondary side circuit restoring the transmitted signal based on a level of a voltage pulse generated across the secondary winding of the relevant insulating transformer.

14. The power electronics equipment according to claim 1, further comprising: a primary side circuit making a pulse current flow through the primary winding of the insulating transformer, a level of the pulse current being different corresponding to rising and falling edges of a transmitted signal transmitted via the relevant insulating transformer, anda secondary side circuit restoring the transmitted signal based on a level of the voltage pulse generated across the secondary winding of the relevant insulating transformer.

15. The power electronics equipment according to claims 1, further comprising: a primary side circuit making a pulse current flow through the primary winding of the insulating transformer, number of the pulses in a pulse current being different corresponding to rising and falling edges of the transmitted signal transmitted via the relevant insulating transformer, anda secondary side circuit restoring the transmitted signal based on a voltage pulse train generated across the secondary winding of the relevant insulating transformer.