Compact plug-in series hybrid vehicle

Abstract

To promote popularization of electric vehicles in a broad sense by addressing problems of shortage of charging spots and complexity of charging for reduction in a capacity of a battery being the largest problem for popularization of electric vehicles as a countermeasure against global warming, reduction in a cruising distance and security of the cruising distance.SOLUTION: In a plug-in hybrid vehicle equipped with a relatively small-capacity battery, driving from a departure point to a destination is performed by maximizing the use of battery charging power charged by a standard charging device installed at a home parking location or the like. However, when shortage in the battery charging power is anticipated for driving from the departure point to the destination, driving is performed to the destination by charging the battery with the minimum required power to reach the destination using a power generation and charging device such as a gasoline engine mounted on a vehicle.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a plug-in series hybrid vehicle that is equipped with a relatively small capacity battery, which is charged using a normal charging device installed in the vehicle owner's home parking space or the like, and that makes maximum use of the charging power of the battery for driving the vehicle, and if there is a risk of a shortage of battery power before reaching the destination while traveling, the power required to reach the destination is replenished by a generating / charging device such as a gasoline engine installed in the vehicle, thereby extending the vehicle's cruising range. [Background technology]

[0002] The main purpose of converting vehicles to electric vehicles is to reduce CO2 emissions as a measure against global warming. However, in order to ensure a certain driving range, the battery capacity must be increased, which results in a heavy vehicle and a high vehicle price, and the CO2 reduction effect is not as great as expected. As a result, the spread of electric vehicles in Japan has been significantly delayed. To solve this problem, it is necessary to primarily consider how to minimize the capacity of the battery in accordance with the intended use of the vehicle, how to charge the battery simply and effectively, and how to efficiently replenish the charging power when it is insufficient.

[0003] Specific measures to address the reduction in vehicle range caused by reducing the capacity of batteries in current vehicle configurations include expanding charging spots, energy-saving driving by regenerative braking or coasting to a target deceleration / stop point, and reducing running resistance by reducing the running speed or vehicle weight, but these individual measures alone are insufficient and inappropriate for the widespread use of small EVs, including hybrid vehicles (Patent Document 1, Patent Document 2, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2018-046735 [Patent Document 2] Patent Publication No. 2019-054726 [Patent Document 3] Patent Publication No. 2021-088361 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to substantially resolve and alleviate the biggest challenges in the popularization of small EVs, namely, the lack of driving range due to relatively small capacity batteries and the hassle of battery charging, thereby promoting the popularization of small plug-in series hybrid vehicles as small EVs in a broad sense. [Means for solving the problem]

[0006] As a measure to resolve the above issues, we will first consider simplifying battery charging in preparation for the start of a journey, formulating a rational driving plan using charged power from the vehicle's starting point to its destination, and utilizing and managing battery charging power efficiently and effectively under corresponding actual driving conditions. The vehicle is intended primarily for driving in urban areas. In principle, the battery is charged before the vehicle starts to run using a normal charging device installed in the vehicle owner's parking space at home, etc. The average daily driving distance of a small vehicle in Japan is said to be about 70 km. The vehicle must have a battery capacity of 10 to 15 kWh, which is sufficient to run on a full charge, including this average daily driving distance and the power consumption of auxiliary equipment such as air conditioning and lighting while driving, and the battery must be charged normally, preferably using renewable energy, for about 8 hours at night.

[0007] In the plug-in series hybrid vehicle shown in Figure 1, As shown in FIG. 2, before starting travel from the starting point, the vehicle searches for a route to the destination point of the day, and travels the distance Do between the starting point and the destination point based on the battery full charge power (Ebf- It is determined whether it is possible with the battery fully charged power (Ebm). If it is possible, that is, if the driving distance Do is less than or equal to the cruising distance Dc, normal driving to the destination is performed with the battery fully charged power. If it is impossible, that is, if the driving distance Do' is greater than or equal to the cruising distance Dc (i.e., Dc < Do'), supplementary charging to the battery is attempted by a power generation / charging device such as an engine mounted on the vehicle. As shown in FIG. 1, supplementary charging is performed until the battery power Ebt at that point and location is equal to the power assumed to be sufficient for driving from that point and location to the destination, that is, Ebt = Ebs (where Ebs is the power required for the vehicle to reach a point at a distance of Do' during normal driving). After that, as shown in FIG. 1C, supplementary charging is stopped and driving is continued toward the destination. Here, the battery power consumption per unit driving distance is calculated based on the actual battery power consumption results of the most recent actual driving including the current day, including the power consumption of auxiliary equipment such as air conditioners and lighting devices during driving in addition to the power for motor driving, as a general rule.

Advantages of the Invention

[0008] As a result, the vehicle can drive to the destination with the battery charging power Ebt at the current point and location, that is, when the battery charging power Edt required for driving from the current location to the destination is considered, Ebt > Edt, and in this case, normal driving is performed toward the destination. However, if it is determined that driving to the destination with the battery charging power Ebt is impossible, that is, Ebt < Edt, driving with supplementary charging corresponding to the driving state of the vehicle is performed. As a result, when the battery power reaches a state where it satisfies the power required for driving to the destination, supplementary charging is stopped for driving after that point and location, and normal driving is performed. By performing the operations as described above, the plug-in series hybrid vehicle according to the present invention can reach the destination with the minimum power supplement by a power generation / charging device such as an engine, that is, with the minimum CO2 emission power, even in the case of driving over a cruising distance where the frequency of requiring power above the battery charging power by plug-in is low, in addition to being able to drive within the power consumption range of the battery charging power by plug-in, that is, to drive to the destination within the average driving distance range. [Brief description of the drawings]

[0009] [Figure 1] 1 is a conceptual diagram showing control of plug-in charging and supplementary charging by the engine for the power storage device in a plug-in series hybrid vehicle according to the present invention; [Diagram 2] This is a battery power vs. mileage relationship diagram showing the relationship between battery power and mileage according to the present invention in the case of driving without supplemental charging (when the destination is point O), and in the case of driving with supplemental charging (when the destination is point O'). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] To implement the present invention, it is necessary to make some improvements to the car navigation device that constitutes part of the motor / engine drive control unit 6 shown in Fig. 1. Specifically, it is necessary for the device to have a function for grasping the charging state of the battery, and to have characteristics of the vehicle's mileage including the battery power consumption and auxiliary equipment consumption such as the air conditioner and lighting. Here, with regard to the battery power consumption and vehicle mileage characteristics, it is effective to use the past mileage including the current day of the vehicle, as well as the actual power consumption when using vehicle accessories such as air conditioners and lighting. EXAMPLES

[0011] FIG. 1 shows a conceptual diagram of the configuration of a plug-in series hybrid vehicle according to the present invention. In FIG. 1, engine 2 is a generator driven by the engine 1; 3 is a battery that charges external plug-in power and supplements the power generated by the generator 2; 4 is a vehicle drive motor powered by the battery 3; 5 is a vehicle drive wheel driven by a vehicle drive motor; 6 is a motor / engine drive control unit that inputs accelerator / brake information, speed information, position information, destination information, and battery power remaining information of the vehicle and outputs the motor drive control signal / supplementary power control signal to the engine; It is.

[0012] FIG. 2 shows a conceptual diagram of vehicle drive control when the distance between the departure point and destination (Do) is within the cruising range Dc, or when the distance between the departure point and destination (Do') is within the cruising range Dc' (where (Dc' - Dc) is the maximum possible extended driving distance with additional charging). In FIG. Line A (straight line (Ebf-Dc)) represents the driving distance characteristics using plug-in charging power, and in this figure it shows that the remaining battery power upon reaching the destination point (distance D0 point) is Ebo. B (straight line (Ebf-Ds)) represents the mileage characteristics with plug-in charging power + top-up charging power. C (line (Ebs-Do') represents the mileage characteristics from point Ds to point Do' after auxiliary charging is stopped, It is. [Industrial Applicability]

[0013] By configuring and controlling as described above, if the battery charging power at the starting point is sufficient to travel from the starting point to the destination, the vehicle will use the plug-in charged battery power, and if the plug-in charged battery power is insufficient and the vehicle cannot reach the destination, the vehicle will operate the supplementary charging function by driving the engine from the start of travel to obtain the minimum supplementary power required to reach the destination (after the supplementary power reaches the power required to reach the destination, the engine drive for obtaining supplementary power will stop and the vehicle will travel only on battery power thereafter), making it possible to reach the destination with the minimum supplementary power. In other words, the problem of insufficient driving range of small-capacity batteries can be alleviated by charging the vehicle when not in use, such as at the vehicle owner's home parking lot, driving using the charged power, and minimally operating the supplementary charging device such as the engine while driving.

[0014] Although the main subject of the present invention is a small plug-in series hybrid vehicle as described above, it is not necessarily limited to small vehicles. It can also be applied to medium and large vehicles by optimizing the auxiliary charging power generation capacity of the engine, etc., for obtaining supplementary charging power, to the power output for extending the driving range. Furthermore, by adding a manual on / off control function to the supplementary power control as an input signal to 6 (motor / engine drive control unit) shown in Figure 1, it becomes possible to use the supplementary charging power for purposes other than vehicle driving control (for example, as household power or outdoor recreational power). [Explanation of symbols]

[0015] Eb: Battery charging power Ebf: Battery full charge power Ebm: Battery minimum charging power Ebo: Battery power when reaching the destination of distance Do Ebt: Current battery power Ebs: Battery power required for distance (Do'-Ds) travel Ed: Battery power required to travel from the starting point to the destination Edt: Battery power required to travel from the current point to the destination point (point O) Ed't: Battery power required to travel from the current point to the destination point (point O') D: Vehicle mileage Dc: Driving range (distance that can be traveled with a fully charged battery (Ebf-Ebm)) Do: Distance between starting point and destination point (point O) Do': Distance between starting point and destination point (point O') Dt: Distance between the vehicle's current location and the destination Ds: Auxiliary charging stop point distance

Claims

[Claim 1] The vehicle is equipped with a battery having a capacity capable of storing a sufficient amount of power required to drive the vehicle's average daily driving distance, and the battery can basically be charged by normal plug-in charging for a certain period of time (e.g., 8 hours) or less at a parking place such as the vehicle's home. Before starting to travel, the route and distance from the starting point to the destination are searched for, and the amount of charge power to be stored in the vehicle's battery is identified. It is then determined whether or not the vehicle can travel from the starting point to the destination with the amount of charge power. If possible, the vehicle travels normally toward the destination. A small plug-in series hybrid vehicle characterized in that, when it is expected that the battery charging power provided by the plug-in will be insufficient to travel to the destination, the vehicle thereafter travels by motor drive using the battery charging power, while supplementary charging of the battery is performed using a generation and charging function provided by the engine, and the battery power Ebt including the supplementary charging power is periodically determined, and when the battery power Ebt becomes equal to or greater than the power Edt required to travel to the destination, i.e., when Ebt > Edt, supplementary charging is stopped, and the vehicle thereafter travels to the destination using battery power.

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