CN104253536A - Driving power source system for electric vehicle - Google Patents

Abstract

The invention discloses a driving power source system for an electric vehicle. The driving power source system comprises a power source, a transformer and IGBT (insulated gate bipolar transistor) units, wherein the transformer comprises a primary side and a plurality of auxiliary sides, the primary side is connected with the power source and used for converting voltage of the power source into multiple channels of output voltage, the IGBT units are connected with a driving circuit respectively, the driving circuit is composed of the auxiliary sides of the transformer and a driving module, and output voltage of each auxiliary side of the transformer is used for providing independent driving voltage of the IGBT units respectively.

Description

Driving power supply system for electric vehicle

Technical Field

The present invention relates to a driving power supply system for an electric vehicle, and more particularly, to a multi-output driving power supply system for two-wheel or four-wheel driving.

Background

With the increasing severity of energy crisis and environmental pollution problems, the development of electric vehicles has become a hot point of research. The main working principle is that a battery (lithium battery or lead-acid battery) is mounted on a vehicle, and then direct current of the battery is converted into three-phase chopping voltage through a power converter to supply power to a motor, so that the rotation speed of a TM (technical motor) driving motor is adjusted, and electric energy is converted into mechanical energy to enable the vehicle to travel.

Fig. 1 shows a circuit topology diagram of a power converter driven by a single TM motor. The circuit comprises an input voltage Us provided by a battery, a filter capacitor Cs and an asymmetric half-bridge circuit consisting of main switching devices T1-T6 and freewheeling diodes D1-D6 of the power converter. The main switching devices T1-T6 are respectively connected to a driving power supply system, which includes a driving circuit unit formed of a driving chip M57962AL (not shown) for precisely controlling the on and off thereof. Since the main switching devices T1-T6 of the power converter shown in fig. 1 need to provide a positive on voltage of +25V and a negative off voltage of-9V, their driving power supply system needs to provide positive and negative voltages to the respective driving chips. IGBTs are commonly used as switching devices with their voltage control characteristics.

As can be understood by those skilled in the art, the IGBT unit driving power supply of the vehicle motor driver has the characteristics of high voltage isolation, multiple groups of outputs, high temperature resistance, electromagnetic interference resistance and the like. From the topology analysis of the current switching power supply, the flyback power supply topology is suitable for the IGBT unit driving power supply for the vehicle. The flyback power supply has the advantages of simple structure, high cost performance, simplicity in control, multi-winding cross adjustment and the like. In the application of the IGBT unit, particularly in the medium-power and high-power IGBT unit, each IGBT unit driving circuit needs to be powered by an independent driving power supply, so as to reduce the influence of the parasitic inductance of the bus.

Fig. 2 is a view showing a structure of a motor driving power supply. The system comprises a battery power supply 10, a power supply and a controller, wherein the battery power supply is used for supplying power to the whole vehicle; the transformer 11 comprises at least one primary side and a plurality of secondary sides and is used for converting the battery voltage into power supply voltage required by each part of the electric vehicle system; the control part 12 further includes a PWM control unit for generating a PWM signal by a signal detected from a feedback circuit of the electric vehicle system and controlling on and off times of the switch 13, thereby controlling the operation of the transformer 11. The transformer 11 further includes a plurality of secondary windings, wherein two windings (dashed boxes 113) that are commonly grounded are used to supply power to the units in the control portion 12; the three isolated secondary side windings (shown by a dotted line frame 111) are used for providing power for the IGBT units of the upper half bridge arms of the three paths, and the three isolated +25V windings are used for independently providing power; due to the limitation of the number of pins (for example, 14 pins) in the transformer framework structure, the three power switching tubes of the lower half-bridge are grounded, a secondary winding (shown by a dashed box 112) is used for supplying power to a common +15V, and the three power switching tubes are connected to the same secondary winding in parallel. Wherein the control power supply and the driving power supply need to be isolated. The control power supply is three paths of common ground power supplies of +/-5V and +/-25V, which are provided for a control circuit, such as a PWM control unit and a feedback detection unit, and are required during operation.

Fig. 3 is a pin diagram of a prior art transformer. The power supply comprises a control power supply leading-out pin and a driving power supply leading-out pin. The pins 13 and 14 are used for connecting a primary coil, and the other pins are used for connecting secondary coils, wherein the pins comprise L1-L3 coils which respectively provide driving voltages for the three IGBT units, and the secondary coils connected with the pins 5 and 6 can provide common-ground driving voltages for the three IGBT units; the rest is the secondary output voltage of the control part.

However, the power supply system having the above structure has the following disadvantages:

(1) a drawback of flyback power supplies is that the power level is limited. If the dual-motor power converter driving is realized by using the single TM motor power converter driving power transformer shown in FIG. 3, two driving power control boards are needed, so that the structure of the power converter is complex, and the simultaneous setting of dual-motor driving signals is difficult;

(2) in addition, three paths of the generated +25V power supply and the-9V power supply are shared, mutual influence of voltages among the three paths cannot be avoided when the transformer is wound, and the obvious phenomenon is that the shared three paths of driving voltages are 1-2V lower than the independent power supply voltage, so that the IGBT cannot be reliably switched on and switched off.

(3) Moreover, the power supply system can only supply power to the single-wheel drive motor in the electric vehicle, and more than two power supply systems are needed to be arranged to respectively supply power to each electric wheel if power needs to be supplied to the two-wheel drive motor or even the four-wheel drive motor. Thus, the volume of the control panel is increased, and unnecessary space is wasted.

Disclosure of Invention

In view of the above, the present invention provides a multi-output driving power source for two-wheel driving of an electric vehicle.

In order to achieve the above object, the present invention provides a driving power circuit for an electric vehicle, including,

a battery power source;

the transformer comprises a primary side and a plurality of paths of secondary sides, wherein the primary side is connected to the power supply and is used for converting the power supply voltage into a plurality of paths of output voltages;

the IGBT units are respectively connected to the multi-path secondary sides of the transformer;

the secondary side output voltage of each transformer is used for providing independent driving voltage for each IGBT unit.

Wherein,

the number of the IGBT units is 12;

the transformer comprises a framework and a winding coil on the framework;

the bottom of the skeleton includes 32 stitches.

Wherein,

the 32 pins comprise 1 path of primary winding input and 16 paths of secondary winding output;

wherein,

the 16 outputs comprise feedback supply windings;

3 control end power supplies;

12 paths of mutually isolated driving power supplies;

1-way feedback circuit power supply.

Wherein,

the 3 control end power supplies are respectively a +15V winding, a-15V winding and a +5V winding; the 12 isolated drive power supplies are +25V windings.

The present invention further provides a transformer comprising:

a framework; an upper winding and a magnetic core;

the number of the pins at the bottom of the framework is more than 14.

Wherein,

the number of the pins is 32.

The driving power supply transformer and the driving power supply circuit designed by the invention are only required to be designed on the same driving circuit board, so that raw materials are saved, the structure of the power converter is simple, the TM motor is convenient to control, most importantly, all driving power supplies are mutually independent, and stable +25V and-9V power supplies are provided for M57962 AL.

Drawings

FIG. 1 is a schematic diagram of a power converter in an electric vehicle;

FIG. 2 is a diagram of a prior art driving power supply;

FIG. 3 is a schematic diagram of a transformer pin in the driving power supply shown in FIG. 2;

FIG. 4 is a block diagram of a power supply system according to an embodiment of the invention;

FIG. 5 is a schematic diagram of a transformer structure of a power supply system according to an embodiment of the invention;

FIG. 6 shows a pin diagram of a transformer according to the present invention;

FIG. 7 illustrates a dual wheel drive power connection according to the present invention;

fig. 8 shows a four-wheel drive power connection according to the present invention.

Detailed Description

The technical solution of the present invention will be described in further detail with reference to the accompanying drawings and embodiments of the present invention.

Fig. 4 is a block diagram of a power supply system according to the present invention. The power supply system of the present invention is different from the power supply system shown in fig. 2 in that the power supply system of the present invention can be used to provide independent driving power for a plurality of IGBT units.

Fig. 5 is a block diagram showing a transformer according to the present invention. Including a fixed bobbin 20, windings thereon, and a magnetic core. The bottom of the framework 20 is fixed with pins; the framework is provided with a wire slot 21 for winding a winding coil. In order to enable the output voltage of the secondary side coil to simultaneously drive 12 IGBT units, the number of required pins and output circuits is large, the invention adopts a specially-made transformer with a 32-pin base, a matched magnetic core is EE40, and the magnetic core can completely meet the requirement of 100W transmission power.

The output of the driving power source includes: the eleven-path isolated power supply voltage is used for supplying power to the driving circuit and ensuring that the driving circuit is not interfered by the power supply side, so that the stable work of the IGBT unit and the normal operation of the motor are ensured; and a common ground control voltage for powering the control system. One path of isolation feedback voltage is used for supplying power to the PWM control chip, so that normal work is ensured.

The on-voltage of the driving circuit can be designed according to the characteristics of the driving chip, for example, the invention adopts an M57962AL chip, and the driving voltage is +24- +26V, preferably + 25V; the power supply of the control section may provide a corresponding voltage, e.g. +5V, ± 15V, according to the needs of the respective control unit.

Fig. 6 shows a pin diagram of a transformer according to the invention. The transformer comprises 32 pins, wherein one primary side input and sixteen secondary side outputs are provided, and +5V and +/-15V power supplies share one ground, so that a 32-pin transformer base is adopted. L17 is a primary winding, L16 is a feedback circuit power supply winding, L13 is a +15V power supply winding, L14 is a-15V power supply winding, and L15 is a +5V power supply winding. And the rest is a +25V power supply winding for supplying power to the driving module. The number of turns of the secondary winding of the +5V power supply is 4; the number of turns of the secondary winding of the +15V power supply is 11; the number of turns of the secondary winding of the +25V power supply is 17.

The outputs of the secondary sides L1-L12 are respectively connected to 12 IGBT unit switching tubes, so that 12 paths of IGBT units can be controlled. Since L13-L15 are common, the outputs thereof can be used to control other power control circuits. In this way, a greater number of IGBT cells can be connected, as shown.

The winding mode of the transformer winding is that the magnetic core is wound around the primary winding from inside to outside, and then a 2500V electrical isolation layer and an electromagnetic shielding layer are manufactured. And winding +5V, +15V and-15V, grounding the three windings, and insulating the windings. Then the +25V winding is wound again, and finally the +15V feedback winding is wound.

It will be appreciated that the secondary output voltage can be set to different magnitudes by the ratio of the primary and secondary sides of the transformer. According to the scheme of the invention, more IGBT units can independently supply power, and the influence of parasitic inductance does not exist, so that a power supply system can be used for simultaneously driving and supplying power to two wheels or four wheels of the electric vehicle, and as shown in fig. 7, when a driving power supply is provided for the two-wheel power converter, each path of power can be independently supplied to the IGBT units.

Further, it can be understood that, when the four-wheel power converter is provided with a driving power supply, as shown in fig. 8, the transformer may also adopt the connection manner as shown in fig. 2, and supply power to the IGBT units of the upper half-bridge in each wheel of the power converter independently, and supply power to the three-way common-ground IGBT units of the lower half-bridge in each wheel of the power converter by adopting one way. Thereby saving space in the TM motor power converter.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims (7)

1. A drive power supply system for an electric vehicle, comprising:

a battery power source;

the transformer comprises a primary side and a plurality of paths of secondary sides, wherein the primary side is connected to the power supply and is used for converting the power supply voltage into a plurality of paths of output voltages;

the IGBT driving system units are respectively connected to the multi-path secondary sides of the transformer;

the secondary side output voltage of each transformer is used for providing independent driving voltage for each IGBT driving system unit.

2. The drive power supply system for an electric vehicle according to claim 1, characterized in that:

the number of the IGBT units is 12;

the transformer comprises a framework and a winding coil on the framework;

the bottom of the skeleton includes 32 stitches.

3. The drive power supply system for an electric vehicle according to claim 1, characterized in that:

the 32 pins comprise 1 primary winding input and 16 secondary winding outputs.

4. The drive power supply system for an electric vehicle according to claim 3, characterized in that:

the 16 paths of outputs comprise a feedback power supply winding, 3 paths of control end power supplies, 12 paths of mutually isolated driving power supplies and 1 path of feedback circuit power supply.

5. The drive power supply system for an electric vehicle according to claim 4, characterized in that: the 3 control end power supplies are respectively a +15V winding, a-15V winding and a +5V winding; the 12 isolated drive power supplies are +25V windings.

6. A transformer, comprising:

a framework; an upper winding and a magnetic core;

the number of the pins at the bottom of the framework is more than 14.

7. The transformer of claim 6, wherein:

the number of the pins is 32.