JPH11178356A - Controller for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate manufacture of a transformer and attain size reduction by monitoring the secondary winding of an isolation transformer for driving an insulation gate bipolar transistor in an inverter circuit, and controlling main voltage to function as a floating power source. SOLUTION: A main power source V10 which is subjected to DC ringing by forming a capacitor C10 between electrodes is supplied in the primary windings h11 to h16 of six insulation transformers 11 to 16. The transistor Q10 is connected in series with the primary winding, and by a control circuit 10 which is connected to its base, voltage supplied to the primary winding is controlled. A capacitor C11 is formed between the electrodes of a power source V11 outputted via a diode D11 serially-connected to the secondary winding h17 of an insulation transformer 11 and feedbacks to the control circuit 10. The voltage outputted via diodes D12 to D16 serially-connected to secondary windings h18 to h22 functions as power source V12 to V16, and the power sources V11 to V16 of six systems are supplied to the IGBT of a motor driving inverter main circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a floating power supply for driving an IGBT, and more particularly to an insulated power supply for a control circuit for driving a motor for an electric vehicle.

[0002]

2. Description of the Related Art IGB of inverter main circuit for motor drive
In order to drive T, a power supply (hereinafter, referred to as a floating power supply) is required for each of the six power supplies. FIG. 2 is a circuit diagram showing a first example of a conventional floating power supply. This is an example where the secondary winding of the main transformer is directly used as a floating power supply. A power supply V20 having a capacitor C20 provided between the electrodes and being DC-linked.
Is supplied to the primary winding h21 of the insulating transformer 110. A transistor Q20 is provided in series with the primary winding h21. The control circuit 101 is connected to the base of the transistor Q20. The control circuit 101 controls the current flowing through the primary winding h21. Secondary windings h22 to h27 are provided on the secondary side of the insulating transformer 110. The output of each of the secondary windings h22 to h27 is
The power supplies are V21 to V26. Each secondary winding h22 to h27
Are connected in series with diodes D20 to D25, respectively. Capacitors C21 to C26 are provided between the electrodes of the power supplies V21 to V26, respectively. The voltage of the power supply V21 is fed back to the control circuit 101. The output power supplies V21 to V26 are supplied to the IGBT of the motor driving inverter main circuit.

[0003] With such a circuit, the control circuit 101
Controls the voltages of the power supplies V21 to V26, which are all floating power supplies, while monitoring the voltage of the power supply V21. FIG. 3 is a circuit diagram showing a second example described in JP-A-8-172772. In this example, four output voltages are configured. The control circuit 1 controls the main insulation transformer 2
Of the primary winding h1 is controlled. The power supply V1 output from the secondary winding of the insulating transformer 2 is fed back to the control circuit 1. In parallel with the secondary winding h2 of the insulating transformer 2, the insulating transformers 21, 31, 41, 51
Primary windings h3 to h6 are connected. The output voltages of the secondary windings h7 to h10 of the insulating transformers 21, 31, 41, and 51 become power supplies V2 to V5. These four power supplies V2
To V5 are supplied to the power transistors of the motor driving inverter main circuit.

[0004]

However, when the secondary winding of the main transformer is directly used as a floating power supply as shown in FIG. 2, the size of the main transformer becomes large. Therefore, a large mounting space is required when mounting the device on a substrate. Further, there is a problem that the manufacturing method becomes complicated in order to ensure insulation between the windings and an insulation distance between pins.

A method for connecting the secondary side of the main transformer to the primary side of the next-stage transformer as shown in FIG.
In order to construct four output voltages, an extra circuit for constructing V1 was required, which was uneconomical. In addition, there is a problem that the efficiency of the entire circuit is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a floating power supply for driving an IGBT which is easy to manufacture and uses a small transformer.

[0007]

According to the present invention, in order to solve the above-mentioned problems, in an IGBT driving floating power supply for driving a plurality of IGBTs in a motor driving inverter circuit, a primary winding is set to a main voltage. A plurality of IGBTs connected to supply an output voltage of a secondary winding to the IGBT;
A control circuit for controlling the main voltage by monitoring the output voltage of one of the plurality of transformers and having a primary winding of the transformer connected in parallel; A control device for an electric vehicle is provided.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an example of a floating power supply for driving an IGBT according to the present invention. In the figure, a main power supply V10 provided with a capacitor C10 between electrodes and DC-ringed is connected to one of six insulating transformers 11-16.
It is supplied to the next windings h11 to h16. Primary winding h1
A transistor Q10 is connected in series to 1 to h16. A control circuit 10 is provided at the base of the transistor Q10.
Is connected. The control circuit 10 controls the voltage supplied to the primary windings h11 to h16.

The secondary winding h17 of the insulating transformer 11
, A diode D11 is connected in series. A capacitor C11 is provided between the electrodes of the power supply V11 output via the diode D11. Power supply V1
1 is fed back to the control circuit 10.

[0010] Secondary windings h of the other insulating transformers 12 to 16
18 to h22 include diodes D12 to D16, respectively.
Are connected in series. The voltages output via the diodes D12 to D16 are the power supplies V12 to V16. Capacitors C12 to C16 are provided between the electrodes of the power supplies V12 to V16, respectively. These six power supplies V
11 to V16 are IGs of the motor drive inverter main circuit.
Supplied to the BT.

As described above, the control circuit 10 uses the power supply V1 by a circuit using a small insulating transformer having a simple structure.
1, the voltages of the power supplies V11 to V16, which are all floating power supplies supplied to the IGBT, can be controlled. As a result, each insulating transformer 11
16 can be reduced in size, and the mounting space of the substrate can be reduced. Further, since the structure of each transformer is simple, manufacturing is easy. Therefore, each transformer becomes inexpensive. In addition, there is an advantage that the number of circuits required for IGBT driving is sufficient and an extra power supply circuit is not required.

[0012]

As described above, according to the present invention, in the IGBT driving floating power supply for driving a plurality of IGBTs in the motor driving inverter circuit, the primary windings of the transformer are connected in parallel. Since the secondary output voltage of the transformer is used as the floating power supply for driving the IGBT, the size of the insulating transformer is reduced. Further, the structure of the transformer is simply reduced, and an inexpensive transformer can be used. In addition, there is an advantage that it is sufficient to provide the number of times necessary for IGBT driving, and no extra power supply circuit is required.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a floating power supply for driving an IGBT according to the present invention.

FIG. 2 is a circuit diagram showing a first example of a conventional floating power supply.

FIG. 3 is a circuit diagram showing a second example of a conventional floating power supply.

[Explanation of symbols]

10: control circuit, 11, 12, 13, 14, 15, 16
... Insulation transformer.

Claims (1)

[Claims] An inverter circuit for driving a motor includes a plurality of I / Os.
An IGBT driving floating power supply for driving a GBT includes a plurality of IGBT driving insulating transformers that connect a primary winding to a main voltage and supply an output voltage of a secondary winding to the IGBT. A control device for an electric vehicle, comprising: a primary winding connected in parallel, a control circuit for monitoring an output voltage of one secondary winding among the plurality of transformers and controlling the main voltage. .