JP2011239540A - Charging circuit for in-vehicle battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging circuit that charges an in-vehicle battery while suppressing a peak of an input current to the in-vehicle battery to perform leveling.SOLUTION: A charging circuit includes: a clock unit 2 that determines the present time; an input unit 3 for inputting a time of use of a vehicle, a display unit 6 that displays the present time, the time of use of the vehicle, a maximum chargeable time, a rating capacity of an in-vehicle battery 9, a remaining battery amount, a charged battery amount, and a minimum charging current; a storage unit 7 that stores the present time, the time of use of the vehicle, the rating capacity of the in-vehicle battery 9, the remaining battery amount, the charged battery amount, and the minimum charging current; a calculating unit 4 that calculates the maximum chargeable time by subtracting the present time from the time of use of the vehicle, calculates the charged battery amount by subtracting the remaining battery amount from the rating capacity of the in-vehicle battery 9, and calculates the minimum charging current by dividing the battery charging amount by the maximum chargeable time; and a control unit 5 that charges the in-vehicle battery 9 at the minimum charging current.

Description

  The present invention relates to a charging circuit for charging a vehicle-mounted battery such as an electric vehicle from a household power source.

In a conventional general vehicle battery charging method, a current supplied from a commercial power source is charged into the vehicle battery via an AC / DC converter. As shown in FIG. 5, the configuration includes a commercial power supply 8 that supplies power to the in-vehicle battery 9, and a charging circuit B that includes an AC / DC conversion unit 1 that converts an alternating current from the commercial power supply 8 into a direct current. And an in-vehicle battery 9 that stores the electric power converted by the AC / DC converter 1. A constant current-constant voltage method is generally employed as a method for charging the vehicle-mounted battery 9. In this constant current-constant voltage method, at the start of charging, a spare current is supplied to detect the voltage of the in-vehicle battery 9, and the battery is charged with a constant current based on the detected voltage of the in-vehicle battery 9 (= constant). In the current charging mode), when the remaining amount of the vehicle-mounted battery 9 increases and the voltage reaches near the charging end voltage, the voltage is fixed at the upper limit and charged at a constant voltage (= constant voltage charging mode). The constant current charging mode automatically shifts to the constant voltage charging mode. As shown in FIG. 4, in the constant current charging mode at the initial stage of charging, the power supplied from the commercial power supply 8 is large and a large input current flows regardless of the remaining battery level of the in-vehicle battery 9.
JP-A-9-130982

  However, in the constant current charging mode in the initial stage of charging, a large amount of input current is required, and thus there may be a need to restrict use of other home appliances. In order to avoid restrictions on the use of other home appliances, it is conceivable to increase the contract capacity of the breaker, but in that case, the basic charge for electricity charges will increase. In addition, since charging is performed in a short time, the temperature rise of the in-vehicle battery is large, which causes the deterioration of the in-vehicle battery.

  Therefore, the present invention is based on the above prior art, and an object of the present invention is to provide a charging circuit that charges an in-vehicle battery while suppressing the peak of the input current to the in-vehicle battery and leveling it. is there.

In order to achieve the above object, in the invention of claim 1, in a charging circuit for charging a vehicle-mounted battery using electric power supplied from a commercial power source,
A timekeeping section that measures the current time,
An input unit for inputting the time of use of the car;
A display unit that displays the current time, the car use time, the maximum chargeable time, the rated capacity of the vehicle-mounted battery, the remaining battery level, the battery charge amount, and the minimum charge current value;
A storage unit for storing a current time, a car use time, a maximum chargeable time, a rated capacity of the vehicle-mounted battery, a remaining battery capacity, a battery charge amount, and a minimum charge current value;
Calculate the maximum chargeable time by subtracting the current time from the vehicle usage time, obtain the rated capacity and remaining battery level of the vehicle-mounted battery from the vehicle-mounted battery, and calculate the remaining battery level from the rated capacity of the vehicle-mounted battery. Calculating the battery charge amount by subtracting the amount, dividing the battery charge amount by the maximum chargeable time, and calculating a minimum charge current value;
The vehicle-mounted battery charging circuit has a control unit that charges the vehicle-mounted battery with the minimum charging current value.

  According to the first aspect of the present invention, the minimum charging current value is calculated from the maximum chargeable time and the battery remaining amount, and the vehicle-mounted battery is charged with the minimum charging current value, so that the peak of the input current to the vehicle-mounted battery is obtained. The battery can be charged while suppressing leveling and leveling. Therefore, it is possible to suppress an increase in the temperature of the in-vehicle battery during charging, and to reduce deterioration of the in-vehicle battery. In addition, it becomes difficult to exceed the contracted capacity of the breaker, and there is no need to restrict the use of other home appliances.

  The present invention relates to a charging circuit for charging an in-vehicle battery using electric power supplied from a commercial power source, a time measuring unit for measuring the current time, an input unit for inputting a vehicle use time, a current time, a vehicle Use time, maximum chargeable time, rated capacity of in-vehicle battery, remaining battery level, battery charge amount, minimum charge current value, and current time, car use time, maximum chargeable time, in-vehicle A storage unit for storing the rated capacity of the battery, the remaining battery level, the battery charge amount, the minimum charge current value, and calculating the maximum chargeable time by subtracting the current time from the car use time, and from the vehicle battery Obtain the rated capacity and remaining battery level of the in-vehicle battery, subtract the remaining battery level from the rated capacity of the in-vehicle battery, calculate the battery charge amount, and minimize the battery charge amount. By having a calculation unit that calculates the minimum charging current value divided by the chargeable time and a control unit that charges the in-vehicle battery with the minimum charging current value, the peak of the input current to the in-vehicle battery is suppressed. The battery can be charged while leveling.

  FIG. 1 is a conceptual diagram showing the overall configuration of a charging circuit A according to the present invention. The charging circuit A includes an AC / DC conversion unit 1, a timer unit 2, an input unit 3, a calculation unit 4, a control unit 5, a display unit 6, and a storage unit 7. The AC / DC converter 1 is connected to a commercial power supply 8 via an input terminal (not shown), and converts an alternating current supplied from the commercial power supply 8 into a direct current. The time measuring unit 2 is a clock and measures time. The input unit 3 is, for example, a numeric keypad or a keyboard that allows the user of the charging circuit A to input the use time of the car. The calculation unit 4 can be configured by, for example, a CPU (= Central Process Unit), and by reading and executing an application program, OS, control program, or the like stored in the storage unit 7, the configuration of the charging circuit A A command is sent to each part, or it operates and controls various functions of the charging circuit A by itself. In particular, the calculation unit 4 calls the car use time and the current time from the storage unit 7 and subtracts the current time from the car use time to calculate the maximum chargeable time. Also, the rated capacity and remaining battery capacity of the in-vehicle battery 9 are called, and the battery charge amount is calculated by subtracting the remaining battery capacity from the rated capacity. Further, the minimum charge current value is calculated by dividing the battery charge amount by the maximum chargeable time.

  The control unit 5 is a control circuit that is connected to the in-vehicle battery 9 via an output terminal (not shown) and controls the voltage and current output to the in-vehicle battery 9. The control unit 5 includes the calculation unit 4. Charging is performed with the minimum charging current value calculated in (1). The display unit 6 controls the charging circuit A and various information such as the current time measured, the input time of use of the car, the maximum chargeable time, the battery charge amount of the in-vehicle battery 9, the minimum charge current value, and the like. A liquid crystal display, an organic EL display, a monitor, etc. that display commands and response outputs. The storage unit 7 includes, for example, a RAM (= Random Access Memory) that temporarily stores information and files necessary for program execution and functions as a work area capable of high-speed communication with an arithmetic device such as a CPU. ing. In particular, the storage unit 7 has the rated capacity and remaining battery capacity of the in-vehicle battery 9 acquired from the in-vehicle battery 9, the battery charge amount calculated by the calculation unit 4, the current time, the car use time, the maximum chargeable time, The minimum charging current value and the like are stored, and the calculation unit 4 functions as a work area for calculation. The storage unit 7 and the in-vehicle battery 9 are connected so as to be able to communicate with each other, and the storage unit 7 acquires the rated capacity and remaining battery capacity of the battery from the in-vehicle battery 9.

  The AC current supplied from the commercial power supply 8 via the input terminal (not shown) is converted into a DC current by the AC / DC conversion unit 1, and the control unit 5 uses the minimum charging current value calculated by the calculation unit 4. The in-vehicle battery 9 is charged through an output terminal (not shown). On the other hand, the direct current converted by the AC / DC converter 1 is also supplied to an internal power supply (not shown). The internal power supply unit is for securing a power supply in the charging circuit A, and is connected to the timer unit 2, the input unit 3, the calculation unit 4, the control unit 5, the display unit 6, and the storage unit 7.

  Next, the flow of charging using the charging circuit A will be specifically described with reference to FIG. The user of the charging circuit A connects the commercial power supply 8 to the input terminal (not shown) of the charging circuit A, and connects the vehicle battery 9 to the output terminal (omitted) of the charging circuit A. First, the calculation unit 4 acquires the rated capacity of the battery and the current remaining battery level from the in-vehicle battery 9 and stores them in the storage unit 7. In addition, the calculation unit 4 acquires the current time from the time measuring unit 2 and stores it in the storage unit 7. On the other hand, the user of the charging circuit A inputs the use time of the car using the input unit 3. The input time of use of the car is stored in the storage unit 7. Next, the calculation unit 4 calls the rated capacity and the remaining battery capacity of the in-vehicle battery 9 from the storage unit 7, and calculates the battery charge amount by subtracting the remaining battery capacity from the rated capacity of the in-vehicle battery 9. The calculation unit 4 calls the current time and the car use time from the storage unit 7 and calculates the maximum chargeable time by subtracting the current time from the car use time. Then, the minimum charge current value is calculated by dividing the battery charge amount by the maximum chargeable time. Then, the control unit 5 starts charging at the minimum charging current value calculated by the calculation unit 4. When the remaining amount of the battery increases and the voltage reaches near the end-of-charge voltage, this voltage is fixed at the upper limit and the mode is automatically shifted to the constant voltage charging mode.

  In this way, the minimum charging current value is calculated based on the maximum chargeable time and the battery charge amount, and in the constant current charging mode at the initial stage of charging, the vehicle battery 9 is charged with this minimum charging current value. Therefore, as shown in FIGS. 3 and 4, charging can be performed while suppressing the peak of the input current to the in-vehicle battery 9 and achieving leveling as compared with the conventional method. Therefore, the temperature rise of the vehicle-mounted battery 9 during charging can be suppressed, and deterioration of the vehicle-mounted battery 9 can be reduced. More specifically, “t1” shown in FIG. 3 indicates the charging start time when charging is started at the minimum charging current value in the constant current charging mode at the initial stage of charging. The current is reduced to 1/2. In addition, as shown in FIG. 4, in the charging circuit A, when the battery remaining amount is 0%, the charging initial current is suppressed to ½, and when the battery remaining amount is 50%, the charging circuit A is charged. The initial current is reduced to 1/4. In addition, “t2” illustrated in FIG. 3 indicates a state in which the use of other home appliances has started and the input current has increased. In the conventional method, the input current increases to the contracted capacity, and it is necessary to restrict the use of other home appliances. On the other hand, in charging circuit A, there is a margin between the input current and the contracted capacity of the breaker, and there is no need to restrict the use of other home appliances. Note that “t3” shown in FIG. 3 indicates the transition to the constant voltage charging mode.

  In the present embodiment, the maximum chargeable time is calculated based on the current time and the car use time. However, the user of the charging circuit A inputs the maximum chargeable time using the input unit 3. It is good also as composition to do. With such a configuration, the object of the present invention for charging the vehicle-mounted battery 9 with a minimum charge current value can be achieved with a simpler configuration, which is convenient.

  Further, in the present embodiment, the input unit 3 is provided in order for the user of the charging circuit A to input the use time of the car, but the display unit 6 is a touch panel and the input unit 3 is not provided. It is good also as a structure which inputs the utilization time of a car directly from the display part 6. FIG.

It is a conceptual diagram which shows the whole structure of the charging circuit A which concerns on this invention. It is a flowchart which shows the flow of charge using the charging circuit A which concerns on this invention. It is a graph which shows the time-input current characteristic of the charging circuit of a conventional system, and the graph which shows the time-input current characteristic of the charging circuit A which concerns on this invention. 5 is a table showing characteristics such as an initial charging current of a conventional charging circuit, and a table showing characteristics such as an initial charging current (= minimum charging current value) of the charging circuit A according to the present invention. It is a conceptual diagram which shows the whole structure of the charging circuit B of a conventional system.

A: charging circuit, B: charging circuit,
1: AC / DC conversion unit, 2: timing unit, 3: input unit, 4: calculation unit, 5: control unit, 6: display unit, 7: storage unit, 8: commercial power supply, 9: vehicle-mounted battery

Claims (1)

In a charging circuit that charges an in-vehicle battery using electric power supplied from a commercial power source,
A timekeeping section that measures the current time,
An input unit for inputting the time of use of the car;
A display unit that displays the current time, the car use time, the maximum chargeable time, the rated capacity of the vehicle-mounted battery, the remaining battery level, the battery charge amount, and the minimum charge current value;
A storage unit for storing a current time, a car use time, a maximum chargeable time, a rated capacity of the vehicle-mounted battery, a remaining battery capacity, a battery charge amount, and a minimum charge current value;
Calculate the maximum chargeable time by subtracting the current time from the vehicle usage time, obtain the rated capacity and remaining battery level of the vehicle-mounted battery from the vehicle-mounted battery, and calculate the remaining battery level from the rated capacity of the vehicle-mounted battery. Calculating the battery charge amount by subtracting the amount, dividing the battery charge amount by the maximum chargeable time, and calculating a minimum charge current value;
A charging circuit for an in-vehicle battery, comprising a control unit that charges the in-vehicle battery with a minimum charging current value.

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