KR20130109848A - Apparatus for supplying auxiliary power in electric vehicle - Google Patents

Abstract

PURPOSE: An auxiliary power supply apparatus for an electric vehicle is provided to improve efficiency in utilizing energy without enlarging and complicating the same. CONSTITUTION: An auxiliary power supply apparatus for an electric vehicle includes a transformer (15), a converter (41), an inverter (42), and an electricity accumulating unit (43). The transformer drops alternating current power collected from a catenary wire, and supplies the alternating current power to a main motor (31). The converter converts the transformed alternating current power into direct current power. The inverter converts the input direct current power into the alternating current power, and outputs the alternating current power to an auxiliary unit (44). The electricity accumulating unit at the direct current input side of the inverter is connected between an anode and a cathode. The electricity accumulating unit is charged with power from the catenary wire, and is charged with regenerative power from the main motor. [Reference numerals] (44) Auxiliary unit

Description

Auxiliary power supply for electric vehicles {APPARATUS FOR SUPPLYING AUXILIARY POWER IN ELECTRIC VEHICLE}

The present invention relates to an auxiliary power supply, and more particularly to an auxiliary power supply for use in an electric vehicle.

Background Art Conventionally, an auxiliary power supply apparatus for an electric vehicle having electric storage means for charging electric power and regenerative electric power of a main motor and supplying the electric power to a main motor and various auxiliary devices as necessary is known.

1 is a block diagram of a conventional auxiliary power supply.

In the case of the AC electric vehicle 100 as shown in FIG. 1, the AC power is collected by the current collector 102 from the wire 101. The electric vehicle 100 transforms the collected AC power by the transformer 103 and then controls the power supplied to the main motor 106 by the converter 104 and the inverter 105. The DC / DC converter 107 which varies a DC voltage is connected to the DC output side of the converter 104, and the electrical storage means 108 of a lithium ion battery is connected to the output side of this DC / DC converter 107. . The power storage means 108 has a relatively large charging capacity, and generally charges and discharges electric power for driving the main motor 106.

However, in the conventional electric vehicle 100, in order to charge and discharge the power storage means 108, a DC / DC converter 107 for varying the voltage of the DC power output from the converter 104 is required. Therefore, there is a problem that leads to an increase in devices and equipment, and to an increase in size and complexity of the device.

On the other hand, in the case of the electric vehicle 100 without the power storage means 108, for example, when the power failure of the household wire 101 or the power cannot be regenerated, the power generated by the regeneration is consumed by thermal energy or by a mechanical brake. You need to brake. For this reason, there is a problem that energy waste occurs.

The technical problem to be solved by the present invention is to provide an auxiliary power supply device for an electric vehicle with high energy utilization efficiency without causing the enlargement and complexity of the device.

In order to solve the above technical problem, the auxiliary power supply device of the present invention, transformer for stepping down the AC power collected from the wire and supply to the main motor; A converter for converting AC power transformed into the transformer into DC power; An inverter connected to the DC power output side of the converter and converting the input DC power into AC power and outputting the AC power to the auxiliary device; And power storage means connected between the positive electrode and the negative electrode at the direct current input side of the inverter and charging electric power from the wire and regenerative electric power from the main motor.

In one embodiment of the present invention, it is preferable that the power storage means discharges power to the main motor and the auxiliary device when the power supply from the wire stops.

In one embodiment of the present invention, the power storage means, the charging capacity is preferably secured so that the filling rate is 100% or less.

The present invention as described above has the effect of increasing the energy use efficiency without causing the enlargement and complexity of the device.

1 is a block diagram of a conventional auxiliary power supply.
2 is a diagram illustrating an embodiment of an electric vehicle auxiliary power supply device according to the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Terms including ordinals such as first, second, etc. may be used to describe various elements, but the elements are not limited by such terms. These terms are used only to distinguish one component from another.

When a component is said to be 'connected' or 'connected' to another component, it may be directly connected to or connected to that other component, but other components may be present in between. It should be understood that. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, or a combination thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram illustrating an embodiment of an electric vehicle auxiliary power supply device according to the present invention.

As shown in the figure, in the present invention, the electric vehicle 10 includes a current collector 11 and a wheel 12. The current collector 11 is configured by, for example, a pantograph and slides on the wire 13 to which AC power is supplied. The electric vehicle 10 travels as the wheels 12 roll on the tracks.

The electric vehicle 10 forms an electric circuit between the current collector 11 in contact with the wire 13 and the wheel 12 in contact with the track, and collects power from the wire 13. Between the current collector 11 and the wheels 12, the circuit breaker 14 and the transformer 15 are sequentially connected from the current collector 11 side.

The breaker 14 opens and closes an electric circuit formed between the current collector 11 and the wheel 12. In addition, the transformer 15 steps down the AC power collected from the current collector 11. The transformer 15 has a primary coil 21, a secondary coil 22, and a tertiary coil 23 between the current collector 11 and the wheels 12.

The electric vehicle 10 includes a converter 32 and an inverter 33 for controlling the power supplied to the main motor 31. In addition, the electric vehicle 10 includes the auxiliary power supply 40 of the present invention.

As shown in the figure, the auxiliary power supply 40 includes a converter 41, an inverter 42 and a battery 43 as power storage means.

The converter 32 and the converter 41 are AC / DC converters by pulse width modulation (PWM) control for converting AC power into DC power.

Specifically, the converter 32 is connected to the secondary coil 22 of the transformer 15. In addition, the converter 41 is connected to the tertiary coil 23 of the transformer 15. As a result, the converter 32 and the converter 41 are collected from the wire 13 by the current collector 11 and convert the AC power transformed by the transformer 15 into DC power, The voltage is controlled and output.

The inverter 33 is connected to the DC power output side of the converter 32. The inverter 33 converts the DC power input from the converter 32 into three-phase AC power and outputs it to the main motor 31. Specifically, the inverter 33 is configured as a VVVF inverter that outputs three-phase AC power whose voltage and frequency are varied according to the running state of the electric vehicle 10 from the DC power input from the converter 32.

In addition, the inverter 42 is connected to the DC power output side of the converter 41. The inverter 42 is configured as, for example, a stationary inverter that outputs an AC power having a constant voltage and frequency from the DC power input from the converter 41.

The main motor 31 is a three-phase induction motor and is driven by a three-phase AC power output from the AC output side of the inverter 33. The main motor 31 is mechanically connected to the wheel 12 using a drive mechanism (not shown). As a result, the driving force generated in the main motor 31 is transmitted to the wheel 12 via the driving mechanism. As a result, the electric vehicle 10 travels on the track by the driving force generated by the main motor 31.

At least one auxiliary device 44 is connected to the AC power output side of the inverter 42. The auxiliary device 44 is, for example, various equipment such as an air conditioner, a lighting and a compressor. The air conditioner and lighting illuminate the air conditioning in the cabin of the electric vehicle 10 and the interior and exterior of the cabin. The compressor generates compressed air for supplying a braking device, an air spring, or a door opening and closing device of the electric vehicle 10. The auxiliary device 44 is driven by three-phase power or single-phase AC power supplied to the inverter 42.

The battery 43 as the power storage means is composed of, for example, a secondary battery such as a lithium ion battery. In addition, the power storage means may be constituted by an electric double layer capacitor instead of the battery 43. Such a battery 43 and an electric double layer capacitor have a high durability against repeated charging and discharging and a sufficient charging capacity. The battery 43 is connected between the positive electrode and the negative electrode at the DC output side of the converter 41. A part of AC power collected from the temporary line 13 is charged in the battery 43 via the tertiary coil 23 and the converter 41 of the transformer 15. In addition, the regenerative power generated by the main motor 31 when the electric vehicle 10 is braked is charged in the battery 43 as necessary.

The converter 41 controls the DC voltage to output. In this case, the converter 41 changes the DC voltage applied to the battery 43 in accordance with the detected charge capacity of the battery 43. Thereby, charging and discharging of the battery 43 are controlled in accordance with the DC voltage output from the converter 41.

The voltage output from the tertiary coil 23 of the transformer 15 is set lower than the voltage output from the secondary coil 22. Thereby, the voltage input from the tertiary coil 23 to the converter 41 and from the converter 41 to the battery 43 is also set low. As a result, the insulation specification of the electric circuit from the tertiary coil 23 to the battery 43 is simplified.

In this way, by controlling the charging and discharging of the battery 43 by the DC voltage output from the converter 41 provided for supplying power to the auxiliary device 44, a converter dedicated to the battery is not necessary, and the battery 43 Insulation specifications of the surrounding circuit are also simplified. Therefore, the size and weight of the device can be reduced.

Hereinafter, the operation of the auxiliary power supply device 40 of the electric vehicle 10 having the above configuration will be described.

When the electric vehicle 10 is in a state capable of collecting current from the household line 13, the battery 43 is charged by a part of the collected electric power. The charge rate of the battery 43 is controlled by the DC voltage output from the converter 41. In the present invention, it is preferable that the charging capacity is ensured so that the charging rate of the battery 43 is 100% or less. In other words, the battery 43 is controlled in such a situation that it can always be charged.

When the electric vehicle 10 is running, the electric vehicle 10 collects AC power from the temporary line 13 by the current collector 11. The collected AC power is supplied to the main motor 31 through the transformer 15, the converter 32, and the inverter 33. Thereby, the main motor 31 generates the driving force which drives the wheel 12, and the electric vehicle 10 runs.

On the other hand, when the electric vehicle 10 is at the time of braking, the electric vehicle 10 functions as the generator to perform the regenerative braking. The electric power generated by the main motor 31 at the time of braking is applied to the secondary coil 22 of the transformer 15 via the inverter 33 and the converter 32 in reverse to the time of travel. At this time, when the regeneration is effectively functioning, the power applied to the secondary coil 22 is returned from the primary coil 21 to the wire 13 through the current collector 11. As a result, the electric power generated by the main motor 13 in response to the braking of the electric vehicle 10 is regenerated to be consumed by another electric vehicle running in the same section.

On the other hand, when the regeneration does not function effectively, that is, when the regeneration effect occurs, the AC power applied to the secondary coil 22 is transferred from the tertiary coil 23 through the converter 41 to the battery 43. Is charged. For example, if the power consumption of another electric vehicle traveling in the same section falls below the regenerative power of the electric vehicle, the regenerative efficiency that cannot sufficiently regenerate power generated by the main motor 31 through the cross section or at the time of power failure Occurs.

As such, when the regenerative failure occurs, the electric vehicle 10 needs to consume power generated by the main motor 31 as heat with a resistor, etc., not shown, or brake using a mechanical brake. In the present invention, as described above, since the charging rate of the battery 43 is always secured, even when the regeneration effect occurs in this way, the power generated by the main motor 31 is charged by the battery 43. Is regenerated.

The electric power charged in the battery 43 is consumed by the driving of the auxiliary device 44 or the main motor 310. For example, when the power supply is stopped from the wire line 13 due to a power failure, the electric vehicle 10 The compressor for generating air conditioning, lighting, and compressed air is driven according to the electric power charged in the battery 43. In this case, the electric power charged in the battery 43 is converted after the inverter 42 converts the AC power. Supplied to the device 44.

In one embodiment of the present invention as described above, the battery 43 is connected to the DC input side of the inverter 42, that is, the DC output side of the converter 41, DC power input from the converter 41 to the inverter 42 Will be charged accordingly. The DC power output from the converter 41 for supplying power to the auxiliary device 44 is lower than the DC voltage output from the converter 32 for supplying power to the main motor 31. Therefore, the battery 43 is directly charged or discharged in accordance with the DC power output from the converter 41 without using a dedicated DC / DC converter.

As a result, the battery 43 is charged in accordance with the power from the power line 13 and the regenerative power from the main motor 31. In particular, when regenerative effectiveness occurs, the power generated by the main motor 31 is recovered in accordance with the charging of the battery 43. Therefore, the efficiency of energy utilization can be improved without incurring enlargement and complexity of the apparatus. In addition, by recovering the power generated in the main motor 31 to the battery 43, the use of the mechanical brake during braking is reduced. Thus, wear of the mechanical brake can be reduced.

In the present invention, the battery 43 can also supply electric power to the main motor 31 by discharging. For this reason, even when the electric vehicle 10 is stopped in the state which cannot collect current from the temporary wire 13, the electric vehicle 10 can be re-run by the electric power by the discharge of the battery 43. FIG.

In the present invention, the battery 43 discharges to supply power to the auxiliary device 44. Therefore, even when the electric vehicle 10 is stopped in the state where electric power cannot be collected from the wire 13, the electric vehicle 10 can be rerun and power is supplied from the battery 43 to the auxiliary device 44. Therefore, the safety of the electric vehicle 10 in an emergency can be improved.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the true scope of the present invention should be determined by the following claims.

10: electric car 31: main motor
41: converter 42: inverter
43: battery 44: auxiliary device

Claims (3)

A transformer for stepping down the AC power collected from the wire and supplying it to the main motor;
A converter for converting AC power transformed into the transformer into DC power;
An inverter connected to the DC power output side of the converter and converting the input DC power into AC power and outputting the AC power to the auxiliary device; And
And power storage means connected between a positive electrode and a negative electrode at a direct current input side of said inverter, for charging electric power from said wire and regenerative electric power from said main motor.
The method of claim 1,
And the power storage means discharges electric power to the main motor and the auxiliary device when the power supply from the wire stops.
The auxiliary power supply according to claim 1, wherein said power storage means secures a charging capacity such that the charging rate is 100% or less.

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