JP2008259281A - Electric vehicle and its power supply device - Google Patents

Abstract

【Task】
How to provide a series hybrid electric vehicle with good fuel efficiency and power, which has a problem to be solved by the thermal efficiency of the power generation engine and the electricity storage means of the generated electricity.
[Solution]
As an electric vehicle, a power generation engine is installed to operate at a constant speed with high thermal efficiency at any time, the surplus power is stored, the power generation engine is automatically stopped, and fuel consumption is improved by running on the stored power. It can be improved dramatically. As the power feeding device, an electric vehicle with good acceleration can be obtained by providing a composite storage battery as a power storage means.
[Selection] Figure 1

Description

  The present invention relates to an electric vehicle in which a traveling motor that drives traveling wheels is driven by an engine via a power storage unit, and a power supply apparatus for the electric vehicle.

  2. Description of the Related Art Conventionally, there has been known a vehicle of a type in which electric power of a generator driven by a power generation engine is temporarily stored in a storage battery, and driving wheels are driven by the electric power, that is, an electric vehicle equipped with a so-called series-type hybrid power feeding device. (See Patent Document 1).

  This type of electric vehicle is configured to constantly replenish the electric power consumed by the electric motor for traveling, and the generator engine is always operated during traveling. On the other hand, the power generation engine is equipped with a power generation engine with a relatively large displacement so that it can run only with the power generated by the power generation engine in consideration of when the storage battery has been discharged. ing.

For this reason, the power generation engine has a large remaining capacity during normal travel, and is therefore constantly operated at a low load. In other words, as is clear from the equal fuel consumption rate curve shown in FIG. 4, since the fuel is operated in a state where the net effective pressure is low, the energy of the fuel is converted into electric energy with a very low conversion efficiency (thermal efficiency). Yes. Therefore, there is a problem that fuel consumption reduction due to hybridization is reduced.
JP 2002-135905 A

  The problem to be solved is to increase the load of the power generation engine and to operate it. The excessive power generation generated when operating the power generation engine with a large output in a load state with high thermal efficiency without causing waste. Processing and the equipment can be simple and inexpensive.

  According to the present invention, as an electric vehicle, power storage means charged by a power generation engine is connected to a travel motor driving a travel wheel via a vehicle speed control means, and the power generation engine is rotated at a constant load with high thermal efficiency and constant load. The most main feature is that electric control means for setting the engine to be operable at a speed and starting and stopping the power generation engine at the lower limit and the upper limit of the charge amount of the power storage means is provided.

  Further, as a power feeding device, the power storage means charged by the power generation engine is connected to a travel motor that drives the travel wheels via the vehicle speed control means, and the power generation engine is operated at a constant rotational speed with a constant load with high thermal efficiency. It is set to be operable, and the storage means is composed of a lead storage battery, a lithium storage battery, and a capacitor that are sequentially connected through a current adjusting means that prevents backflow from the power generation engine to the traveling motor, The main feature is to provide a control means for detecting the amount of charge of the lead storage battery and starting the power generation engine when the amount of charge decreases, and stopping when it is satisfied.

  In the electric vehicle according to the present invention, when charging is required, the power generation engine is set to be operable at a constant rotation speed with a constant load with high thermal efficiency. The operation is not continued in a state where the average effective pressure is low and the average effective pressure is high. Therefore, since there is no useless fuel consumption by the power generation engine, the electric vehicle can be economically operated. Further, while the power storage means is sufficiently charged and the vehicle is traveling by discharging from the power storage means, the power generation engine is stopped and fuel is not consumed unnecessarily.

  In the electric vehicle power supply device according to the present invention, the power storage means functions as a capacitor for excessive charging / discharging that occurs temporarily, a lightweight lithium storage battery functions to increase the electrical energy density, and detects the amount of charge. Lead storage battery works for ease. Therefore, a power storage device group (composite storage battery) that functions organically as a group and has a small outer shape and weight and is easy to handle can be obtained.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a main part of a power supply device 10 for an electric vehicle. In the figure, 12 is a traveling motor for driving the traveling wheel 16, 20 is a storage means for supplying power to the traveling motor 12, and both are accelerated. The vehicle is connected via vehicle speed control means 18 operated by a pedal 19. Therefore, by operating the accelerator pedal 19, a controlled current flows from the power storage means 20 to the traveling motor 12, and the traveling wheel 16 is driven at a speed corresponding thereto.

  Reference numeral 30 denotes a power generation engine that drives an AC charging generator 32. The charging generator 32 is connected to the power storage means 20 via a current adjusting means 22 such as a rectifier or a boosting means (DC / DC converter), and supplies power for charging. In the power storage means 20, a lead storage battery 25, a lithium storage battery (generic name such as lithium ion) 24, and a capacitor 23 are sequentially connected from the power generation engine 30 side to the traveling motor 12 side, and each of them is between Current adjusting means 22 is interposed.

  The storage batteries 25, 24, and 23 forming the power storage means 20 are slightly different in function of holding electric power. As shown in FIG. 5, the capacitor 23 is heavy, but has the ability to instantaneously charge and discharge high power, and is suitable for temporarily storing high power supplied from the power generation engine 30. Although the lithium storage battery 24 is slightly inferior in charge and discharge characteristics, it is lightweight and has an excellent ability to store large electric power, and complements the characteristics of the capacitor 23. The lead storage battery 25 is inferior in both weight and charge capacity but has a long life and has a characteristic that the charge amount can be measured. Since this point is not in the capacitor 23 and the lithium storage battery 24, the lead storage battery 25 is incorporated in the storage means 20. Yes.

In this embodiment, the voltage of the electric power sent to the traveling motor 12 through the vehicle speed control means 18 is usually 336 volts, and when the output voltage of the charging generator 32 is lower than that, the current adjusting means 22 is, for example, DC The DC voltage may be boosted to a predetermined voltage by means of boosting a DC voltage such as a DC converter.

  The power generation engine 30 is loaded with power supplied by the charging generator 32 to the power storage means 20. Regardless of the size of the power storage means 20 as a load, the engine is arbitrarily operated in a state of high thermal efficiency, and the engine automatically starts and automatically stops based on information emitted from the charge amount sensor 34a provided in the power storage means 20.

  Of course, although it is practically the exhaust capacity of a gasoline engine, a compact car class power generation engine 30 is suitable for 400 cc and a light car class about 250 cc.

  Reference numeral 34 denotes electric control means for starting or stopping the power generation engine depending on the amount of charge of the power storage means 20. The electric control means 34 includes a charge amount sensor 34a attached to the lead storage battery 25 and an engine switch 34b having the same function as a starter ignition switch key in a normal automobile.

  The charge amount sensor 34a detects the charge amount of the power storage means 20 represented by the lead storage battery 25, and when the charge amount falls to the lower limit, it issues a signal to the engine switch 34b, and the engine switch 34b energizes the ignition coil. At the same time, the power generation engine 30 is started by supplying power to the starter motor for a short time to supply power to the power storage means 20.

  Next, operation | movement of the electric power feeder of the electric vehicle 10 which concerns on a present Example is demonstrated with FIG. When the electric vehicle 10 is ready to travel, the system of the power feeding device 12 starts. First, the charge amount of the power storage means 20 is checked, and when the charge amount is equal to or lower than the set lower limit, the engine switch 34b operates to start the power generation engine 30. When it is above the lower limit, the stop state is maintained. When the power generation engine 30 is operated and the charge amount exceeds a predetermined upper limit, the engine stops.

  As shown in FIG. 3, when the power generation engine 30 is started in a state where the charge amount has dropped to the lower limit or has already been overdischarged to the lower limit or lower, the power generation engine 30 is on the equal fuel consumption rate curve. It is operated at a constant speed in an area where fuel consumption is low. When the amount of charge reaches the upper limit after a predetermined time has elapsed, the power generation engine is stopped, electric power is consumed by running the electric vehicle, and the stopped state is maintained until the amount of charge decreases to the lower limit.

The upper limit of the above-mentioned amount of stored electricity can be substituted by using a certain time (timer) from the lower limit. Further, in the power storage means 20, the lead storage battery 25 is described as a representative battery because the storage amount is remarkably expressed by liquid specific gravity and voltage. However, the lower limit of the storage amount acts as the charge amount sensor 34a even for the voltage of a lithium ion battery, for example. Therefore, it is a concept including a battery having these functions.

It is the circuit diagram which showed the principal part of the electric power feeder of this-application Example. It is a flowchart which shows operation | movement of an electric power feeder. It is a characteristic view which shows operation | movement of an electric power feeder. It is explanatory drawing which shows the equal fuel consumption rate curve of the engine for electric power generation. It is explanatory drawing which shows the characteristic of the element of an electrical storage means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric vehicle 12 Electric power feeder 14 Driving motor 16 Traveling wheel 18 Vehicle speed control means 19 Accelerator pedal 20 Power storage means 22 Current adjustment means 23 Capacitor 24 Lithium storage battery 25 Lead storage battery 30 Power generation engine 32 Charging generator 34 Electric control means 34a Charging Quantity sensor 34b Engine switch

Claims (4)

  The power storage means charged by the power generation engine is connected to a travel motor that drives the travel wheels via the vehicle speed control means, and the power generation engine is set to be operable at a constant rotational speed with a high thermal efficiency constant load, An electric vehicle provided with electric control means for starting and stopping the power generation engine at a lower limit and an upper limit of a charge amount of the power storage means.   2. The power generation engine according to claim 1, wherein the power generation engine is continuously operated until the amount of charge reaches the upper limit from the lower limit, and is maintained in a stopped state until consumed by the electric motor for travel from the upper limit to the lower limit. Electric car.   The power storage means charged by the power generation engine is connected to a traveling motor that drives the traveling wheels via the vehicle speed control means, and the power generation engine is set to be operable at a constant rotational speed with a high thermal efficiency constant load, The storage means is composed of a lead storage battery, a lithium storage battery, and a capacitor, which are sequentially connected via a current adjusting means for preventing backflow from the power generation engine to the traveling motor, and the charge amount of the lead storage battery A power supply device for an electric vehicle provided with a control means for detecting the engine and starting the power generation engine when the amount of charge decreases, and stopping when the engine is satisfied.   3. The power feeding device according to claim 2, wherein the current adjusting means is a DC voltage booster.

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