JP2014007908A - Rapid charging method and apparatus - Google Patents

Abstract

An external storage battery can be continuously charged, and the capacity of the storage battery for facilities is reduced.
In a rapid charging method using a storage battery for facilities 22 for charging an external storage battery 50 together with power on the power receiving side from a commercial power supply 10, the equipment is installed together with power from the power receiving side during constant current charging in the first half of charging. Electric power is supplied from the storage battery 22 to the external storage battery 50, and at the time of constant voltage charging in the second half of charging, the power is supplied from the power receiving side to the equipment storage battery 22 to charge the equipment storage battery 22.
[Selection] Figure 4

Description

  The present invention relates to a rapid charging method and apparatus, and more particularly, to a rapid charging method and apparatus suitable for use in continuously charging a power lithium ion storage battery mounted on an electric vehicle (also referred to as EV). Relates to the device.

  In recent years, electric vehicles that use electric energy as a driving source have become widespread in the market as a countermeasure against the depletion of petroleum resources and global warming. However, electric vehicles can also be rapidly charged in the same amount of time as ordinary car refueling. There is a need for a charging device.

  Conventionally, as a device capable of rapid charging, for example, a large-capacity facility storage battery is prepared, and when the charging to the electric vehicle is stopped, the facility storage battery is charged over a long time with a low current, and the external storage battery of the electric vehicle When charging a battery, a device for discharging a large current from a storage battery for equipment has been developed (see, for example, Patent Document 1).

  By the way, as the specifications of the quick charging device for the external storage battery of the electric vehicle which is currently announced, a quick charging device of DC 400V, current 125A class is assumed, and accordingly, the power supply from the commercial power supply line also has a circuit efficiency of 90%. When the output is 50 KW, the input power is assumed to exceed 55 KW. In order to receive the supply of large power that satisfies this requirement, unlike the case of low power reception of less than 50 KW, for example, a transformer facility that converts from a high voltage of 6600 V to a low voltage of 200 V is required, and the contract with the power company is large. There was a problem of becoming.

  In order to solve such problems, the applicants in Patent Document 2 add the output of the DC power supply that converts the AC power of the commercial power source to DC power and the output of the facility capacitor in a series circuit to externally Proposed to supply to a storage battery, in Patent Document 3, when charging an external storage battery for power, in addition to a storage battery for equipment, a DC power supply that is charged using a commercial power source is connected in series with the storage battery for equipment or It is proposed to connect in parallel and use it for charging external storage batteries.

JP-A-5-207668 JP 2011-200104 A JP 2012-19602 A

  However, the techniques described in Patent Documents 2 and 3 have a problem that appropriate current voltage control cannot be performed when charging an external storage battery.

  In particular, in recent years, in a lithium ion storage battery that has been widely used as an external storage battery of an electric vehicle, as illustrated in FIG. 1, first, constant current charging of about 125 A is performed from 300 V (350 V in the figure) to 400 V, For example, after charging progresses to a SOC (State of Charge) of 50%, constant voltage charging with an upper limit of 400 V is usually performed until the current changes from 125 A to 0 A for safety.

  However, in the configurations of Patent Documents 2 and 3, when the external storage battery continues to be charged, the remaining amount of the storage battery for facilities decreases as illustrated in FIG. 2, and charging is stopped halfway as illustrated in FIG. It was difficult to continuously charge.

  Moreover, in order to ensure the charge amount required for the storage battery for facilities, it is necessary to increase the capacity of the storage battery for facilities, and there is also a problem that it is large and expensive.

  The present invention has been made to solve the above-described conventional problems, and it is an object of the present invention to enable continuous charging of an external storage battery and to further reduce the capacity of a storage battery for facilities.

  In the rapid charging method using the storage battery for facilities for charging the external storage battery together with the power on the power receiving side from the commercial power source, as illustrated in FIG. 4, at the time of constant current charging in the first half of charging, from the power receiving side. The above problem is solved by supplying power from the storage battery for equipment to the external storage battery together with the power of the battery, and charging the storage battery for power supply by supplying power from the power receiving side to the storage battery for equipment during the constant voltage charging in the second half of charging. It is a thing.

  In addition, in the rapid charging apparatus having the storage battery for facilities for charging the external storage battery together with the power on the power receiving side from the commercial power source, during the constant current charging in the first half of charging, the power storage battery for the external storage battery is connected to the external storage battery from the power receiving side. Quick charge device comprising bidirectional charging control means for supplying power to the facility storage battery from the power receiving side during constant voltage charging in the second half of charging and charging the facility storage battery Is to provide.

  Here, the bidirectional charging control unit compares the power on the power receiving side with the power required for charging the external storage battery, and the power on the power receiving side charges the external storage battery according to the comparison result of the controller. When power is insufficient, supply power from the storage battery to the external storage battery, and when the power on the power receiving side is greater than the power required to charge the external storage battery, supply power from the power receiving side to the storage battery for equipment. A bidirectional DC power supply that is controlled to do so can be included.

  The bidirectional DC power supply can be a bidirectional DC / DC converter.

  Furthermore, the voltage on the external storage battery side of the bidirectional DC / DC converter can be controlled to be constant.

  According to the present invention, not only when charging of an external storage battery is stopped, but also during charging of the external storage battery, the storage battery for facilities can be charged in parallel at the same time when the amount of charge is small. Continuous charging performance can be improved. Accordingly, the required capacity of the facility storage battery is small, and for example, by reducing it to 1/2, the cost of the facility storage battery that occupies most of the cost of the rapid charging apparatus can be reduced to 1/2.

The figure which shows the example of the charge condition of a lithium ion storage battery Time chart showing the problems of the conventional example The time chart which compares and shows the example of the relationship between the number of times of EV charge in the prior art example and the embodiment of the present invention and the remaining battery capacity Diagram showing the principle of the present invention The figure which shows the basic composition of embodiment of this invention. Figure showing the same detailed configuration The time chart which shows the example of the relationship between the charging time and storage battery residual amount in the said embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  A basic configuration of the present embodiment is shown in FIG.

  In the present embodiment, an external storage battery 50 such as a power storage battery for an electric vehicle is supplied from the commercial power supply 10 in the quick charging device 20 having the storage battery 22 for facilities together with the power on the power receiving side from the commercial power supply 10. DC power supply 24 for converting the power on the power receiving side to DC power suitable for charging the external storage battery 50 or the facility storage battery 22, and the power required for charging the power on the power receiving side and the external storage battery 50 According to the comparison result of the controller 26 to be compared with the controller 26, when the power on the power receiving side is insufficient for charging the external storage battery 50, the power is supplied from the facility storage battery 22 to the external storage battery 50, When the power on the power receiving side is larger than the power required for charging the external storage battery 50, the current is supplied from the power receiving side to the facility storage battery 22 so that the facility storage battery 22 is charged. That includes a bidirectional DC power source 28.

  A specific configuration example of the quick charging device 20 is shown in FIG. In the figure, 22A is a lithium ion storage battery constituting the facility storage battery 22, 22B is the same battery monitoring module, 24A is an AC / DC converter constituting the DC power supply 24, 24B is also a DC / AC inverter, 24C. Similarly, for example, a 15 kHz isolation transformer, 24D is also a rectifier, 28A is a bidirectional DC / DC converter constituting the bidirectional DC power supply 28, and 30 is provided on the input side and is cut off when a ground fault is detected. Breaker, 32 is a main switch that is cut in response to an instruction from the controller 26, 34 is a voltmeter, 36 is an ammeter, 38 is a fuse, 40 is a diode, 42 is a ground fault detector, and 44 is a lithium ion This is a switch for disconnecting the storage battery 22A when it overheats.

  The bi-directional DC / DC converter 28A separates a current by an internal IGBT element and puts in and out a direct current power source, and is necessary for the external storage battery 50 while observing the power on the power receiving side and the necessary charging power to the external storage battery 50. The power is controlled to flow from the facility storage battery 22 to the external storage battery 50 side, and when it is left, the power is supplied from the power receiving side to the facility storage battery 22 side. Actually, the controller 26 controls the bidirectional DC / DC converter 28A so that the central DC junction A has a constant voltage.

  Here, since the configuration in the upper part of the drawing including the breaker 30, the main switch 32, the AC / DC converter 24A, the DC / AC inverter 24B, the isolation transformer 24C, and the rectifier 24D is a general configuration, detailed description is omitted. To do.

  In the configuration as shown in FIG. 6, when the storage amount of the lithium ion storage battery 22A is sufficient and the voltage of the DC junction section A is sufficient, the storage battery for facilities receives the maximum power from the commercial power supply 10 side and only the shortage. 22 is supplied. On the other hand, even if the charge amount of the facility storage battery 22 is insufficient and the battery voltage drops, the voltage is boosted by the bidirectional DC / DC converter 28A and does not affect the central DC junction A. However, when the facility storage battery 22 becomes empty, the maximum power from the commercial power supply 10 side cannot be output, and the quick charge is delayed to a medium charge. In addition, as shown in FIG. 4, when it transfers to constant voltage charge and there is a margin in the charge to the external storage battery 50, the storage battery 22 for facilities is supplementarily charged even during the charge of the external storage battery 50, As shown in FIG. 3, it is avoided that the storage amount of the facility storage battery 22 is insufficient after the external storage battery 50 is charged.

  Furthermore, as shown in FIG. 7, by using the configuration of FIG. 6, the remaining capacity of the facility storage battery 22 is not reduced, and charging can be performed continuously.

  In this way, the DC power of the DC power supply 24 from the AC power supply of the commercial power supply 10 and the DC power of the facility storage battery 22 are added together in a parallel circuit by the bidirectional DC power supply 28 and supplied to the external storage battery 50. Therefore, fine current / voltage control is possible, and even when the remaining capacity of the facility storage battery 22 is reduced, the external storage battery 50 can be charged and optimal charging can be performed. Furthermore, even when the external storage battery 50 is being charged, the facility storage battery 22 can be supplementarily charged. Therefore, a decrease in the remaining capacity of the facility storage battery 22 can be compensated, and the external storage battery 50 that has been difficult in the past can be compensated. Can be continuously charged.

  In this embodiment, since the bidirectional DC power supply 28 is used, fine current / voltage control is possible, which contributes to continuous charging of the external storage battery 50. In particular, when the bidirectional DC / DC converter 28A is used to keep the voltage of the central DC junction A constant, the control is easy. The configuration and control method of the bidirectional DC power supply 28 are not limited to this.

  Moreover, in the said embodiment, although the storage battery 22 for facilities was made into the lithium ion storage battery 22A, the storage battery 22 for facilities is not limited to this. Further, the external storage battery 50 is not limited to a power storage battery for an electric vehicle. As in the case of a lithium ion storage battery, the present invention can be applied to any external storage battery that performs constant-current charging at the beginning of charging and constant-voltage charging at the latter half of charging. The same can be applied.

DESCRIPTION OF SYMBOLS 10 ... Commercial power supply 20 ... Rapid charging device 22 ... Facility storage battery 22A ... Lithium ion storage battery 22B ... Battery monitoring module 24 ... DC power supply 24A ... AC / DC converter 24B ... DC / AC inverter 24C ... Insulation transformer 24D ... Rectifier 26 ... Controller 28 ... Bidirectional DC power supply 28A ... Bidirectional DC / DC converter 50 ... External storage battery

Claims (5)

In the quick charging method using the storage battery for facilities for charging the external storage battery together with the power on the power receiving side from the commercial power supply,
During constant current charging in the first half of charging, power is supplied from the storage battery to the external storage battery together with power from the power receiving side, and during constant voltage charging in the second half of charging, power is supplied from the power receiving side to the storage battery for equipment. A rapid charging method, characterized by charging a storage battery. In the quick charging device having the storage battery for facilities for charging the external storage battery together with the power on the power receiving side from the commercial power supply,
During constant current charging in the first half of charging, power is supplied from the storage battery to the external storage battery together with power from the power receiving side, and during constant voltage charging in the second half of charging, power is supplied from the power receiving side to the storage battery for equipment. A rapid charging apparatus comprising bidirectional charge control means for charging a storage battery for use. The bidirectional charging control means is
A controller that compares the power on the receiving side with the power required to charge the external storage battery;
Depending on the comparison result of the controller, when the power on the power receiving side is insufficient to charge the external storage battery, power is also supplied from the storage battery for facilities to the external storage battery, and the power on the power receiving side is required for charging the external storage battery. A bidirectional DC power supply that is controlled to supply power from the power receiving side to the facility storage battery,
The rapid charging apparatus according to claim 2, wherein   The rapid charging apparatus according to claim 3, wherein the bidirectional DC power supply is a bidirectional DC / DC converter.   5. The rapid charging apparatus according to claim 4, wherein the voltage on the external storage battery side of the bidirectional DC / DC converter is controlled to be constant.

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