JPH09168206A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover the recovered charged energy at all times by providing means for controlling the battery capacity constantly to a level close to a target charging level while ensuring a predetermined charging energy at the time of recovery. SOLUTION: DC power is fed from a battery 1 through a power converter 2 to an AC motor 3 thus driving the motor 3. At the time of applying brake or descending a slope, energy of the motor 3 is recovered by regenerative braking and the battery 1 is charged through the power converter 2. A battery capacity controller 6 detects the battery capacity. A required regenerative amount X is calculated based on an estimated run state signal from a navigation system and an actual run state signal from a vehicle run state detector 8 and then a target charging amount α (α=100-X) is calculated therefrom. Finally, the target charging amount α is compared with the battery capacity and the small engine 4 is started thus controlling the battery capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle in which a generator driving engine is mounted on an electric vehicle that drives a motor from a battery via a power converter, and the battery is charged by the output of the generator.

[0002]

2. Description of the Related Art Environmental pollution has become a major problem on a global scale, and exhaust gas emitted from engine vehicles is required to be severely dealt with. In such a situation, electric vehicles have been put into practical use as clean vehicles without exhaust gas in some specific applications, but early realization of electric vehicles that can be put to practical use instead of engine vehicles in a wider range is desired. ing.

The current state of electric vehicles is still inferior to that of engine vehicles in terms of continuous mileage and acceleration performance. In order to guarantee the same drivability as that of an engine vehicle, one of the biggest challenges is to make the battery, which is the power source, smaller and larger in capacity. In addition, in the current electric vehicle equipped with a battery, various problems still remain that must be solved in order to achieve a running performance close to that of an engine vehicle. The drive circuit of a conventional electric vehicle that has been generally put into practical use supplies the DC power of the battery to the motor through the power converter when driving or running the electric vehicle, and also has a regenerative function during braking under reverse load or during downhill driving. Was used to regeneratively charge the battery with the electric power generated by the motor.

However, in this case, the charging amount is limited and the one-charge traveling distance does not extend so much as expected. For this reason, an electric vehicle equipped with a so-called hybrid power source, in which a small engine rotates a generator to charge a battery, as is known from Japanese Patent Laid-Open No. 3-270603, is generally known.

[0005]

However, the battery capacity needs to be constantly charged because the capacity of the battery changes abruptly depending on the running condition of the vehicle. However, if the battery is charged too much, the battery cannot be charged for regeneration. No more energy savings. Also, since it consumes a lot of battery energy when climbing a hill, if recharging with a small engine results in near full charge near the top of the mountain, regenerative braking will be performed when going downhill or braking. It will not come out.

In addition, when it is desired to drive on a high road on a mountainous area for a long time, a state close to the full charge (100 near the top of the mountain)
-There is a demand for keeping the battery capacity at the target charge amount α).

However, in a system in which the capacity of the battery is charged by a generator driven by a small engine, if the battery is always fully charged, regenerative energy during braking or downhill can be returned to the battery. Can not.

Therefore, it is necessary to keep the capacity of the (100-α) regenerative portion in the battery at all times in order to save energy. The (100-α) regenerative amount greatly differs depending on the vehicle running state, the road state (uphill, downhill), etc., so these signals are intensively taken into the battery capacity controller and the target charge amount α value is set as necessary. It is necessary to drive the generator to charge the battery so that the battery capacity reaches the α value. An object of the present invention is to provide an electric vehicle equipped with a battery capacity control system capable of recovering necessary regenerative energy in a battery under any running condition.

[0009]

SUMMARY OF THE INVENTION The present invention is an electric vehicle in which an output of a generator driven by an engine is charged in a battery and a vehicle driving motor is driven by using the electric power as a power source. While ensuring the charging energy (100-α) at the time of regeneration, the capacity detection means, the signal from the detection means, the expected traveling state signal from the navigation system, and the signal indicating the vehicle traveling state are used as input signals. This is achieved by including a battery capacity control unit that constantly controls the battery capacity to a state close to the target charge amount α.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a battery capacity control system for an electric vehicle of the present invention will be described with reference to the drawings.

As shown in the block diagram of FIG. 1, a battery 1 as a drive source of a vehicle is connected in series with an electric power converter 2 and a motor 3, and the battery is driven by using gasoline, light oil, gas or the like as fuel. It is configured to be connected to an output end of a generator 5 that is rotationally driven by the small engine 4 and to be supplied with electric power. The battery capacity controller 6 is shown in FIG.
As shown in, the voltage change (preferably current,
The battery capacity is ascertained by taking in the signal of the correction coefficient such as the temperature in the case). In addition, the battery capacity controller uses traffic information as information from the navigation system 7 mounted on the vehicle to the destination,
The actual traveling state signal of the vehicle is input from the vehicle traveling state detection device 8 to the expected traveling state signal such as topographical information, and the small engine is driven according to the result compared with the battery 1. There is.

On the other hand, the battery capacity indicator 9 displays the battery status as shown in FIG.
Further, the target charge amount α is displayed, and a setting switch 11 is provided so that the driver 10 can easily and arbitrarily set the α value.

In the above structure, the DC power from the battery 1 is supplied to the AC motor 3 via the power converter 2 to drive the motor 3 (solid line arrow in the figure). on the other hand,
When braking or when going down a slope, regenerative energy is collected by the regenerative braking from the motor 3 through the power converter 2 to the battery 1 for charging (broken line arrow in the figure). Since this alone cannot run for a long time, a so-called hybrid power supply system in which the small engine 4 rotates the generator 5 to charge the battery 1 is configured.

The battery capacity controller 6 for grasping the charging / discharging state of the battery 1 detects the capacity of the battery, predicts the traveling state signal from the navigation system 7 and the actual traveling state from the vehicle traveling state detecting device 8. The required regeneration amount X is calculated from the signal, and the target charge amount α is calculated from the calculated value.
The value (α = 100−X) is calculated. Next, comparing the α value with the battery capacity, the start of the small engine 4 is turned ON-OF.
The F capacity is controlled to control the battery capacity. Further, the battery capacity Q is displayed on the battery capacity display 9, and this display is provided with an α set value and a manual switch whose driver 10 can arbitrarily change the set value.

Specifically, as shown in FIG. 3, the target charge amount α value is calculated from the fully charged battery capacity (100) −the required regeneration amount X = α, and the small engine 4 is started when Q−α <0. The battery capacity controller 6 outputs a signal to cause the small engine 4 to start and the battery 1 to be charged. Also Q-α
When ≧ 0, the battery capacity controller 6 outputs a signal for stopping the small engine 4 to stop the small engine 4.

These operations are always repeated, and the battery capacity Q is always in a state as close to full charge (target charge amount α).
To 100) and regenerative energy can be returned to the battery 1.

If the information from the navigation system 7 is viewed at too long intervals, the information that changes from moment to moment cannot be kept and the reliability is low.
It is good to take in about 10 minutes. Further, since the battery capacity Q is displayed on the battery capacity display 9 and the target charge amount α value is also displayed, it is also displayed whether or not the current battery capacity and the charging state are present (α> Q
When the state of charge by the generator).

Further, the manual switch of the battery capacity indicator 9 can arbitrarily change the α set value manually, and when the α set value is manually set, the α value automatically set by the battery capacity controller 6 is used. Also, if the manual switch is turned off, the system will automatically switch to the one that automatically sets the α value.

According to the above embodiment, the battery capacity is accurately grasped, and the state of the land to be driven by the navigation system (elevation and elevation difference,
The required regeneration amount Q is calculated from the signal (distance to the destination) or the actual traveling state signal of the vehicle, and the target charge amount α which is a value obtained by subtracting the required regeneration amount Q from the battery capacity (100% charge) is calculated. . If the current battery capacity is smaller than this α value, the battery capacity controller issues a signal to start the small engine to operate the generator, charge the battery, and when the battery capacity reaches the α value, the battery capacity The system uses a signal from the controller to stop the startup of the small engine.

Therefore, as shown in FIG. 4, the required regeneration amount (1
(00-α) is always maintained, the battery charge is performed as necessary so that the battery capacity Q is always brought close to the target charge amount α, so that the vehicle travels as much as possible (the fuel for the engine runs out. It becomes an electric car that can be operated over a long distance like a gasoline car. In addition, since the required amount of regeneration is always secured, it is possible to recover the maximum amount of regenerative energy when the brake is applied or when traveling on a downhill, which enables energy saving operation.

Since the battery capacity is displayed on the battery capacity display, the driver can arbitrarily specify the α value, and this specification can be changed manually according to the driver's request, so that it is always necessary. The battery capacity can be maintained arbitrarily.

[0022]

According to the present invention, the battery capacity controller detects the capacity of the battery, and the required regeneration amount X is calculated from the predicted traveling state signal from the navigation system and the actual traveling state signal from the vehicle traveling state detector. , The target charge amount α value (α = 100−X) is calculated from this value, and this α
ON-O to start the engine by comparing the value with the battery capacity
Since the FF control is performed to control the battery capacity, necessary regenerative energy can be collected in the battery in any running state, and an energy-saving and highly safe electric vehicle can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a battery capacity control system according to an embodiment of the present invention.

FIG. 2 is an input / output diagram of the battery capacity control system.

FIG. 3 is a diagram showing the same capacity.

FIG. 4 is a battery capacity control state diagram of the same.

[Explanation of symbols]

1 ... Battery (secondary battery), 2 ... Power converter, 3 ... Motor, 4 ... Small engine, 5 ... Generator, 6 ... Battery capacity controller, 7 ... Navigation system, 8 ... Vehicle running state detection device, 9 ... Battery capacity indicator, 10 ... driver.

Claims (5)

[Claims] 1. An electric vehicle in which an output of a generator driven by an engine is charged in a battery and a vehicle driving motor is driven by using the electric power as a power source, a means for detecting the capacity of the battery, and the detection means. The battery capacity is always the target charge amount while ensuring the charging energy (100-α) during regeneration with the signal from the means, the expected traveling state signal from the navigation system, and the signal indicating the actual vehicle traveling state as input signals. An electric vehicle comprising: a battery capacity control means for controlling a state close to α. 2. The electric vehicle according to claim 1, wherein the target charge amount α value of the battery is displayed on a battery capacity indicator. 3. The electric vehicle according to claim 2, wherein the α value shown on the battery capacity indicator can be set arbitrarily. 4. The electric vehicle according to claim 3, wherein the battery capacity indicator is provided with a manual switch for manually switching the α value. 5. The α value set in the manual according to claim 4, wherein the α value automatically determined by the battery capacity controller.
Electric vehicles characterized by prioritizing over value.