JPH05336673A - Centralized charger - Google Patents

Abstract

PURPOSE:To provide a centralized charger realizing concurrent charging of loads, e.g. batteries in a plurality of electric automobiles, compaction, cost reduction, and enhancement of efficiency of power receiving facility. CONSTITUTION:A plurality of chargers 251-253 are provided with a common DC power supply, i.e., a single rectifier 24, and set number of chargers are subjected to time shared charging control through a controller 26. Consequently, a plurality of loads can be charged concurrently and a rectifier receives AC power and supplies DC power equivalent to those for continuous operation of a single charger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for charging a storage battery mounted on, for example, an electric vehicle, and more particularly to a centralized charging device for simultaneously charging a plurality of electric vehicles.

[0002]

2. Description of the Related Art In an electric vehicle, a motor is used as a prime mover, a secondary battery (storage battery) is mounted on its power source, and the motor is controlled by a motor controller. For this reason, the electric vehicle requires a charging device for charging the storage battery mounted therein unlike the refueling of fuel such as gasoline, which is necessary for a conventional vehicle having an internal combustion engine as a prime mover.

FIG. 5 shows a conventional charging device for an electric vehicle. Reference numeral 1 is a charging device, and 2 is an electric vehicle. The charging cable 3 is connected to the output terminals A and B of the charging device 1, and the other end of the charging cable 3 is connected to the input terminals A ′ and B ′ of the electric vehicle 2 to be mounted on the electric vehicle 2. The storage battery 4 is charged.

In the charging device 1, the AC power source 5 is switched to the switch 6
AC power is taken in via the rectifier 7, this AC power is converted into DC power by the rectifier 7, and DC output is obtained at the output terminals A and B via the switch 8. The control unit 9 that constitutes a charger in combination with the rectifier 7 controls the output current and voltage of the rectifier 7 based on the direct current and the direct current voltage detected by the current detection unit 10 and the voltage detection unit 11, and controls the constant current. The storage battery 4 is charged by a charging method such as a constant current voltage method.

The charging device 1 is required to charge the storage battery 4 in a short time in order to popularize and maintain electric vehicles, and the storage battery 4 is capable of rapid charging as the output current is increased and the voltage is increased. Is being improved and research is also underway.

[0006]

In the conventional charging device, the charging voltage and current can be adjusted to some extent according to the voltage and capacity of the storage battery installed in the electric vehicle, but the number of electric vehicles that can be charged at one time is limited. .

Therefore, when the charging device is applied to a charging system having means for performing charging service similar to that of a gas station, the charging device sequentially charges the electric vehicles one by one, and when charging requests are concentrated. It is expected to cause a long waiting time for charging.

This problem can be dealt with by installing a large number of charging devices. However, installing a large number of charging devices only during a time period when charging requests are concentrated will increase installation space efficiency and installation space. It becomes a charging system with a low operating rate and an expensive system.

Further, one charging device requires high power energy (for example, 100 KW to 200 KW) in a short time (for example, 10 to 20 minutes) at the time of charging, and is prepared for the case where a large number of charging devices are operated at the same time. Therefore, the capacity of the power receiving equipment must also be increased, and the equipment efficiency of the power receiving equipment also deteriorates.

An object of the present invention is to provide a centralized charging device which enables simultaneous charging of loads of a plurality of electric vehicles or the like while making the device compact and reducing cost, and further improving efficiency of power receiving equipment. Especially.

[0011]

In order to solve the above-mentioned problems, the present invention uses one rectifier for converting AC power from an AC power supply into DC power, and charges the secondary battery with the rectifier as a DC power supply. It is characterized by comprising a plurality of chargers for obtaining DC power, and a control device for time-divisionally controlling charging of a charger designated for operation among the plurality of chargers.

[0012]

According to the present invention having the above-described structure, a plurality of chargers are controlled in a time-divisional manner so that a plurality of loads can be simultaneously charged, and the rectifier receives only one AC power and one DC power to be supplied. The same as the continuous operation of the charger in.

[0013]

1 is a block diagram showing an embodiment of the present invention, which is applied to a centralized charging device for an electric vehicle.
The charging device 21 includes a commercial AC power source 22 and a circuit breaker 23.
AC power is taken in through the power receiving equipment consisting of The charging device 21 uses one rectifier (AC / DC converter) 24 that converts AC power from a power receiving facility into DC power, and DC power that charges a storage battery of an electric vehicle using the rectifier 24 as a common DC power supply. a plurality of chargers 25 _to 253 to obtain
₃ and a common control device 26 for each of the chargers 25 _{1 to} 25 ₃ .

The control device 26 controls the output of the charger designated to be operated among the chargers 25 _{1 to} 25 ₃ , and the charger to be operated for this charging control uses the DC power from the rectifier 24 in a time sharing manner. And each charger is controlled so as to supply the charging current to the electric vehicle in a time division manner.

In the figure, the charger 25 out of the three chargers
_The case where the operation of ₁ and 25 ₂ is performed is shown, and the number (NO) of the charger to be operated is given to the control device 26 to perform time-divisional charge control of the chargers 25 ₁ and 25 ₂ . The charge amount for each electric vehicle and the voltage type information of the storage battery are also given to this charge control, and each charger 2
The output voltage V _D of 5 ₁ , 25 ₂ is detected and the output current I _D (or input current) of the rectifier 24 is detected to obtain the charge amount for each electric vehicle 2, and the charge current and voltage are calculated according to the charge amount. To control.

FIG. 2 shows a time chart of the time division control of the charging device 21. In the simultaneous operation of the chargers 25 _{1 to} 25 ₃ , the control device 26 controls the chargers 25 _{1 to} 25 ₃ for a certain time T.
Of the charging current output is sequentially given to each of the chargers 25 _{1 to} 25 ₃ to obtain the charging current output only during the given control output period.

Therefore, each of the chargers 25 _{1 to} 25 ₃ simultaneously charges the electric vehicle, but the electric power supplied from the rectifier 24 becomes the same as the electric power continuously supplied to one charger, and The power conversion capacity of itself is the same as the charging capacity of one charger.

Here, as shown in the time chart of FIG. 2, the charging current (and voltage) of each of the chargers 25 _{1 to} 25 ₃ differs depending on the difference in the storage battery capacity and the voltage depending on the type of electric vehicle to be charged. Further, even in the same type of storage battery, depending on the charging state, a relatively large current is used at the initial stage of charging and a relatively small current at the end of charging (a charging state close to the end-of-charge voltage). The required charging current is supplied in a time sharing manner, but the charging current is leveled, that is, the load is leveled.

FIG. 3 shows a concrete circuit diagram of the present invention. The chargers 25 _{1 to} 25 ₃ show the case of the step-up chopper circuit,
When the transistor Tr as a switch element is turned on, a short-circuit current is supplied from the rectifier 24 to the reactor L, and when the transistor Tr is turned off, a charging current is supplied from the reactor L through the storage battery 4 and the flywheel diode D of the electric vehicle 2. At this time, the charging current is controlled by the on / off ratio of the transistor Tr. The charging voltage is detected for each charger by the voltage detector 27 _{1-27 3,} the charging current is simultaneously detected by the current detector 28 as the output current of the rectifier 24 as a current at the output timing of each charger.

The control device 26 has a controller 29 to which a charger number among the chargers 25 _{1 to} 25 ₃ to be operated, a storage battery type of an electric vehicle and a charge amount set value are given as a control center, and is a control target. It detects the voltage and charge for the charger and generates the control output to the charger. The voltage detection switching circuit 30 sequentially switches and fetches the output voltages V _{D1 to} V _D3 of the charger to be controlled by the time division control from the controller 29. The charge amount calculation circuit 31 obtains the instantaneous charge amount of each charger by multiplying the voltage detection signal of each charger from the switching circuit 30 and the current detection value from the current detector 28, and integrates this for each charger. By doing so, the amount of charge of the storage battery of each electric vehicle is obtained and displayed.

The charger control circuit 32 includes the constant value switching circuit 3
Setting value required for each charger from 3 (charger number, charge amount,
Voltage types, etc.) are synchronously switched and given, and the individual control signals (on / off signals of the choppers) of the chargers 25 _{1 to} 25 ₃ are used as feedback signals based on the calculation amount from the switching circuit 30 for these set values. Occur. The gate circuit 34 power-amplifies the control signal for each charger from the charger control circuit 32, and distributes it to each charger 25 _{1 to} 25 ₃ according to the switching control signal from the controller 29 for each charger.

With the above-described structure, the controller 29 is provided with information on each charger to be operated, whereby time-divisional operation control for the charger is performed, and the charging current is controlled for each charger, and a plurality of chargers are controlled. The rectifier input / output power is equivalent to the continuous operation of one charger while simultaneously charging the electric vehicles.

Here, the chargers 25 _{1 to} 25 ₃ have a step-up chopper structure, and the charging operation by the time division control is as shown in FIG. The figure shows the case of time-division control of _two chargers, and the chargers 25 ₁ and 25 ₂ alternately start the charging operation with a cycle T. 1st (NO1) charger 25 ₁
Starts its operation at time t ₁ , the transistor Tr is on-controlled at this timing, and the transistor Tr is off-controlled after a lapse of time T ₁ determined from the set charging current. From this timing t _{2, the} charging current by the reactor L is supplied to the electric vehicle 2 side.

On the other hand, the charger 25 ₂ of the second (NO2) starts operation at the time t _2, the by-off at time t ₃ of the on and after time T ₂ of the transistor Tr in this timing to the electric vehicle 2 The charging current of is supplied until time t ₄ .

Therefore, the period in which the rectifier 24 supplies the DC current is shaded, which is equivalent to supplying the charging current to one charger without a rest period, and the capacity of the rectifier 24 is equivalent to one charger. It only needs to have the same capacity and structure as those of the container, and does not extend the charging time.

In the embodiment, the charger is not limited to the step-up chopper structure but may be any power converter having a DC / DC converting function.

[0027]

As described above, according to the present invention, one rectifier is provided as a common DC power source for a plurality of chargers,
Since the set charger among the chargers is controlled in a time-sharing manner, multiple loads can be charged at the same time, and the rectifier has the same power conversion capacity as continuous operation of one charger. It is possible to reduce the cost and make the equipment compact, and to improve the efficiency of equipment by reducing the capacity of equipment such as power receiving equipment.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention,

FIG. 2 is a time chart of time division control in the embodiment,

FIG. 3 is a circuit diagram of an embodiment,

FIG. 4 is an operation waveform diagram of the embodiment,

FIG. 5 is a configuration diagram of a conventional charging device.

[Explanation of symbols]

2 ... Electric vehicle, 4 ... Storage battery, 21 ... Charging device, 24 ...
Rectifier, 25 ₁ , 25 ₂ , 25 ₃ ... Charger, 26 ... Control device, 29 ... Controller, 30 ... Voltage detection switching circuit, 3
1 ... Charge amount calculation circuit, 32 ... Charger control circuit, 33 ... Set value switching circuit, 34 ... Gate circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Miyake 4-22-13 Himonya, Meguro-ku, Tokyo Hokuto Electric Works Co., Ltd. (72) Hideaki Horie 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co. Within

Claims (1)

[Claims] 1. A single rectifier for converting AC power from an AC power supply into DC power, a plurality of chargers for obtaining DC power for charging a secondary battery using the rectifier as a DC power supply, and the plurality of chargers. A centralized charging device, comprising: a control device for time-divisionally controlling charging of a charger for which operation is designated.