KR20080047638A - Power supply system for electric vehicle - Google Patents

Abstract

A power supply system for an electric vehicle is provided to simplify a structure without requiring an additional voltage drop device and stably offer low voltage electricity to electrical components of the vehicle. A power supply system(200) for an electric vehicle includes one integral type battery module(210) with a plurality of unit modules. Each of the unit modules includes a plurality of battery cells(222,232). The battery module includes both high voltage unit modules(220) for driving a motor(10) and low voltage unit modules(230) for operating electrical components of the vehicle(60). Electricity from the low voltage unit modules is supplied to the electrical components of the vehicle without voltage drop.

Description

Electric Power System {Power Supply System for Electric Vehicle}

1 is a configuration diagram of a power system for an electric vehicle using a battery module as one example of the prior art;

2 is a configuration diagram of a power system for an electric vehicle including a battery module in which the high voltage unit battery module and the low voltage unit battery module are integrally formed according to an embodiment of the present invention.

The present invention relates to a power system of an electric vehicle or a hybrid electric vehicle. More particularly, the power system includes one integrated battery module including a plurality of unit modules, and the battery module includes a high voltage for driving a motor. And a low voltage unit module for operation of the vehicle electric field, and the electricity from the low voltage unit module relates to a vehicle power system configured to be supplied to a vehicle electric field without a voltage drop.

Recently, secondary batteries capable of charging and discharging have been widely used as energy sources of wireless mobile devices. Secondary batteries are also attracting attention as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs), which are proposed as a way to solve air pollution in conventional gasoline and diesel vehicles that use fossil fuels. .

One or two or four battery cells are used for small mobile devices, whereas medium and large battery modules, which are electrically connected to a plurality of battery cells, are used for medium and large devices such as automobiles due to the need for high output and large capacity.

Since the medium-large battery module is preferably manufactured in a small size and weight, the rectangular battery, the pouch-type battery, etc., which can be charged with high integration and have a small weight to capacity, are mainly used as battery cells of the medium-large battery module. In particular, a pouch-type battery using an aluminum laminate sheet or the like as an exterior member has attracted much attention in recent years due to its advantages such as low weight, low manufacturing cost, and easy deformation.

In order for the medium-large battery module to provide the output and capacity required in a predetermined device or device, it is necessary to electrically connect a plurality of battery cells in series and in parallel and maintain a stable structure against external force.

Therefore, in the case of constructing a medium-large battery module using a plurality of battery cells, since a large number of members are generally required for their mechanical fastening and electrical connection, the process of assembling these members is very complicated. Moreover, space is required for joining, welding, soldering, etc. a plurality of members for mechanical fastening and electrical connection, thereby increasing the overall size of the system. This increase in size is undesirable in view of the space limitations of the apparatus or device in which the medium-large battery module is mounted. Furthermore, in order to be efficiently mounted in a limited interior space such as a vehicle, a medium to large battery module having a more compact structure is required.

In addition, the power system 100 of the electric vehicle or hybrid electric vehicle in general, as shown in Figure 1, the battery module 110 composed of a plurality of secondary battery cells 112, the battery management system BMS (Battery Management System) 20) and a number of electrical devices. An inverter 30 converts a high voltage direct current generated from the battery module 110 into alternating current and transmits the alternating current to the vehicle motor 10. The low voltage DC to DC converter 40, which is a DC voltage dropping device, drops a high voltage DC electricity generated from the battery module 110 to a low voltage to transfer it to the controller 50, and the controller 50 transmits the instrument panel and the vehicle audio. Control the operation of the vehicle electric field 60 such as. The BMS 20 controls the battery module 110 according to the state of the battery cell 120 and transmits a signal to an electric device such as the inverter 30 and the LDC 40.

Generally, a high voltage of about 150 V is required for driving a motor of a vehicle, and a low voltage of about 12 V is required for the operation of an electric vehicle (eg, an instrument panel, an audio device, a headlight, etc.). The cells are connected in series, or in series and in parallel, to provide the electricity needed to drive the vehicle motor and to operate the electric field.

Therefore, in the conventional electric vehicle or hybrid electric vehicle, the LDC is used to convert the high voltage DC electricity generated from the battery module to the low voltage electricity for the operation of the electric field requiring the low voltage.

However, due to the LDC, the structure of the automobile power supply device is complicated, and by generating electricity from one battery module and supplying the electric power to the motor and the electric vehicle, when the battery module malfunctions, not only the driving motor of the vehicle but also the electric field are not operated. Occurs. That is, since the battery module is composed of a plurality of secondary battery cells, even if an abnormality occurs in one secondary battery cell, the entire operation of the battery module may be stopped.

Accordingly, Japanese Patent Application Laid-Open No. 2003-061209 discloses that a high voltage main battery module supplies a high voltage electricity to a motor via a junction box and a power drive unit, thereby providing a low voltage auxiliary battery. A module discloses a structure of an automotive power supply unit for supplying electricity to an automotive electric field such as an air conditioner and a wiper. However, in the above technology, since the main battery module and the auxiliary battery module are arranged to be separated from each other, the arrangement structure of the wiring and the control elements becomes complicated, and thus, the overall size of the power supply device increases, and the manufacturing cost also increases. .

In US Patent No. 7095137, one electrical system is composed of a first subsystem (36 V) and a second subsystem (12 V), so that even if one subsystem fails, the other subsystem is operated to load ( A technique for supplying a constant current to the automotive electronics) is disclosed. However, the above-mentioned technique only plays the role of auxiliary power supply when the low voltage second subsystem has an abnormality in the high voltage first subsystem, so the overall system is excellent in stability, but the addition of the first subsystem makes the whole system Has the disadvantage of increasing volume. Furthermore, the technology discloses an electric system structure of a general engine-based vehicle other than an electric vehicle, a hybrid battery vehicle, and the like. For example, the voltage of 36 V proposed in the above technique is approximately 150 V. It is not possible to drive vehicle motors that require high voltages.

In addition, U.S. Patent No. 6791295 discloses low voltage electricity using a DC voltage converter in an electrical system composed of a high voltage battery (36 V), a low voltage battery (12 V), and a DC-to-DC converter. A technique is disclosed for charging a high voltage battery by boosting it to a high voltage and allowing the high voltage battery to be charged only up to a predetermined preset charging limit value. However, the above technique also relates to a method and apparatus for charging a low voltage battery and a high voltage battery of an engine-based vehicle, and can operate only an automotive electric field with a voltage of 36 V, requiring a high voltage of approximately 150 V. It is not possible to drive a vehicle motor.

Therefore, as described above, a vehicle power source capable of supplying electric power to a vehicle motor and an electric vehicle from a battery module having a compact, excellent structural stability and a simple structure to be mounted on a vehicle such as an electric vehicle or a hybrid electric vehicle. The need for a system is high.

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

Specifically, an object of the present invention is to configure the battery module as an integrated unit of a high voltage unit module and a low voltage unit module in an electric vehicle power system of an electric vehicle or a hybrid electric vehicle, the battery without a separate DC voltage dropping device to drop the high voltage to low voltage It is to provide a vehicle power system that supplies the module's electricity to the vehicle electric field.

An automotive power system according to the present invention for achieving the above object is a power system for providing electric power for the operation of the motor and the operation of the vehicle in the electric vehicle or hybrid electric vehicle, the power system is a plurality of unit modules It includes one integrated battery module configured, each of the unit modules is composed of a plurality of battery cells, the battery module is a high voltage unit module for driving the motor and a low voltage unit module for the operation of the vehicle electric field At the same time, the electricity from the low-voltage unit module is configured to include a structure that is supplied to the vehicle electric field without a voltage drop.

After various experiments and studies, the inventors of the present application, when the high voltage unit module and the low voltage unit module are configured as one integrated battery module, the electricity of the low voltage unit module without a separate voltage drop device (LDC) It was confirmed that it can be directly transmitted to the automotive electronics and solve the complexity problem of the power system structure caused by the installation of the voltage drop device.

Therefore, in the power supply system of the present invention, by configuring the high voltage unit module for driving the vehicle motor and the low voltage unit module for the operation of the automotive electric field together under different voltage conditions, the problems of the prior art as described above are raised. Can be solved.

For example, unlike the Japanese Patent Application Publication No. 2003-061209 described above, the power supply system according to the present invention uses a single integrated battery module that includes a high voltage unit module and a low voltage unit module at the same time. The wiring structure and the arrangement of control elements in the system are further simplified, thereby reducing the overall size and manufacturing cost of the power supply system and facilitating manufacturing and repairing operations.

The battery cells constituting the battery module of the vehicle power supply system according to the present invention are not particularly limited as long as they are secondary batteries capable of charging and discharging, but may preferably be nickel-hydrogen secondary batteries or lithium secondary batteries.

The nickel-hydrogen secondary battery is a secondary battery using nickel as a positive electrode, a hydrogen storage alloy as a negative electrode, and an alkaline aqueous solution as an electrolyte, and the energy density per unit volume is nearly twice that of a nickel-cadmium battery, and is higher in capacity than a nickel-cadmium battery. It is possible to withstand over-discharge and overcharge, and has a large capacity per unit volume, it may be preferable as an energy source of an electric vehicle or a hybrid electric vehicle.

In addition, the lithium secondary battery uses a metal oxide such as LiCoO ₂ as a cathode active material and a carbon material as a cathode active material, and places a porous polymer separator between the anode and the cathode and contains a lithium salt such as LiPF ₆ . It is prepared by adding an aqueous electrolyte solution. During charging, lithium ions of the positive electrode active material are released and inserted into the carbon layer of the negative electrode, and during discharge, lithium ions of the carbon layer are released and inserted into the positive electrode active material, and the non-aqueous electrolyte is lithium ions between the negative electrode and the positive electrode. It acts as a moving medium, and because of its high energy density, high operating voltage and excellent preservation and lifetime characteristics, it can be a preferred energy source for a variety of electronics, electric vehicles or hybrid vehicles.

These battery cells make electrical connections in series, or in series and in parallel, to provide a high voltage for driving the motor and a low voltage for operation of the vehicle electric field. For example, since the lithium secondary battery cell generally provides about 3.0 to 4.5 V, at least some series electrical connection is required to provide the high voltage and the low voltage.

The high voltage condition for driving the vehicle motor may vary depending on the driving condition of the vehicle, the type of the motor, and the like, and may be, for example, a voltage of 150 to 300 V. In addition, the low voltage condition for the operation of the vehicle electric field may also vary depending on the setting conditions of the vehicle, for example, may be a voltage of 10 to 30V.

Therefore, the high voltage unit module for driving the motor of the vehicle generates two or more battery cells electrically and mechanically connected in series or in series and in parallel to generate a high voltage DC electricity of 150 to 300 V, and an inverter (Inverter) is It may be configured to convert a high-voltage direct current electric current into alternating current electricity to supply the vehicle motor.

On the other hand, the low-voltage unit module for operating the electric field of the vehicle, two or more battery cells are electrically and mechanically connected in series or in series and parallel, generating a 10 to 30 V DC electricity, a separate DC voltage drop device It can be configured to supply low-voltage direct current electricity to the vehicle electric field without. The low voltage unit module can supply electricity required for the operation of the vehicle electric field even if the high voltage unit module has a problem due to an abnormal operation of some battery cells. For example, since the number of battery cells constituting the high voltage unit module is higher than that of the low voltage unit module, the low voltage unit module configuration as described above is very effective considering the relatively high possibility of failure of the high voltage unit module. have.

The power supply system for automobiles according to the present invention may be used as a power source for an electric vehicle or a hybrid electric vehicle, which has a limited mounting space and is exposed to frequent vibrations and strong shocks, in consideration of mounting efficiency, structural stability, and the like. It can be usefully applied as a power source for electric vehicles.

Therefore, the present invention also provides a hybrid electric vehicle including the power system, the hybrid electric vehicle including a power system capable of charging and discharging is known in the art, a detailed description thereof is omitted herein. do.

Hereinafter, the present invention will be described in more detail with reference to the drawings, but the scope of the present invention is not limited thereto.

2 is a schematic diagram of an electric vehicle power supply system using a high voltage unit battery module and a low voltage unit battery module according to an embodiment of the present invention.

Referring to FIG. 2, the power system 200 includes a battery module 210, a battery module 210, and battery cells 222 and 232 including a high voltage unit module 220 and a low voltage unit module 230. The control and signal transmission function of the BMS 20, consists of a number of electrical devices.

The battery module 210 has an integrated structure including a high voltage unit module 220 and a low voltage unit module 230 together. Here, the integrated structure means that the battery cells 222 constituting the high voltage unit module 220 and the battery cells 232 constituting the low voltage unit module 230 are substantially embedded in one pack case without any distinction. As a whole, it forms a single shape, but means a structure in which the high voltage unit module 220 and the low voltage unit module 230 are formed by only changing electrical connections.

In the high voltage unit module 220, two or more battery cells 240 are connected in series or in series and in parallel (not shown) to supply electricity of approximately 150 to 300 V to the motor 10. The inverter 30 may drive the vehicle by converting the high voltage direct current generated from the high voltage unit module 220 into alternating current and transferring the alternating current to the motor 10.

The low voltage unit module 230 generates 10 to 30 V of electricity required for the operation of the vehicle electric field 60, such as an instrument panel, an air conditioner, an audio, a light, and the low voltage electricity generated from the low voltage unit module 230 is an electric field ( 60 is directly supplied to the vehicle electric field 60 via the control unit 50 for controlling.

The low-voltage unit module 230 for operating the electric vehicle 60 of the vehicle is configured by combining a predetermined number of battery cells 232, thereby lowering the high-voltage DC electricity to a low-voltage DC electricity (Fig. 1; 40 is not required, and even if an abnormality occurs in the high voltage battery module 220, the automotive electric field 60 supplied with electricity from the low voltage module 230 is not affected.

In the process of converting the mechanical energy according to the rotation of the vehicle motor 10 into electrical energy and charging the battery module 220, the rotational energy of the motor 10 is generated as an alternating current through the generator 70 and the rectifier 80. Through the conversion to direct current is to charge the entire battery module 220. Therefore, in the charging process, the battery cells 222 of the high voltage unit module 220 and the battery cells 232 of the low voltage unit module 230 are charged together.

Although the battery module according to an embodiment of the present invention has been described with reference to a drawing of a vehicle power system including a high voltage unit module and a low voltage unit module, those skilled in the art to which the present invention pertains are based on the above contents. It will be possible to make various applications and modifications within the scope of the invention.

As described above, the automotive power system according to the present invention has a compact structure that can be stably mounted in a limited space in a limited space such as a vehicle, and is configured in a simple structure by not requiring a separate voltage drop device. And, it also has the advantage of supplying low voltage electricity to the automotive electronics in a stable manner.

Claims (8)

An electric power system for providing electric power for driving a motor and operating an electric vehicle in an electric vehicle or a hybrid electric vehicle, wherein the power system includes an integrated battery module including a plurality of unit modules, each of which includes: The unit modules are composed of a plurality of battery cells, the battery module includes a high voltage unit module for driving the motor and a low voltage unit module for the operation of the vehicle electric field at the same time, from the low voltage unit module Electric power is supplied to the vehicle electric field without a voltage drop. The vehicle power supply system according to claim 1, wherein the battery cell is a nickel-hydrogen secondary battery or a lithium secondary battery. The vehicle power supply system of claim 1, wherein the battery module is connected to a plurality of battery cells in series, or in series and in parallel. The power supply system of claim 1, wherein the high voltage unit module provides electricity of 150 to 300 volts. The vehicle power system of claim 1, wherein the low voltage unit module provides 10 to 30 V of electricity. The vehicle power supply system of claim 1, wherein the high voltage unit module is converted into alternating current electricity by an inverter and sent to a driving motor. The vehicle power system of claim 1, wherein the low voltage unit module is transmitted to a vehicle electric field without a DC voltage dropping device. An electric vehicle or hybrid electric vehicle, comprising an automobile power system according to any one of claims 1 to 7.

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