JP2012249450A - Charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charger in which deterioration of efficiency and shortening of lifetime is avoided by changing the output of a plurality of power converters for charging a power storage device in various patterns, thereby enhancing the operational reliability and stability.SOLUTION: A charger 10A includes: a rectifier 11 that converts an AC power of an external AC power supply 20 into a DC power; a plurality of AC/DC converters 12 that converts the output power of the rectifier 11 into AC/DC power and supplying the power to a secondary battery 31 as a power storage device from a common output terminal; and a controller 13 that controls the converter 12 so as to charge the secondary battery 31. The controller 13 controls each of the converters 12 so that some of the outputs of the plurality of converters 12 differ from the others.

Description

  The present invention relates to a charging device for charging a power storage device such as a secondary battery (battery) mounted on a vehicle such as an electric vehicle, and more specifically, while incorporating a plurality of power converters and controlling the output thereof. The present invention relates to a charging device that can be selectively supplied to a power storage device.

Conventionally, what was described in patent document 1 is known as this kind of charging device.
In this prior art, a plurality of DC stabilized power supply circuits (power converters that perform AC / DC conversion or DC / DC conversion) are built in the charging device, and the voltages and capacities of a plurality of secondary batteries to be charged are included. The control unit selects a predetermined DC stabilized power supply circuit according to the number, and charges the secondary battery while adjusting the output of these DC stabilized power supply circuits.

  According to the above prior art, it is possible to charge a plurality of secondary batteries individually according to their respective required powers by a plurality of DC stabilized power supply circuits, or to charge specific secondary batteries intensively and rapidly. . Also, by connecting multiple DC-stabilized power supply circuits in parallel, even if some power supply circuits fail, other power supply circuits can be substituted, and the capacity and outer shape of each power supply circuit can be reduced. To facilitate replacement and inspection.

JP 2008-199752 (paragraphs [0024] to [0033], FIG. 1, etc.)

In the prior art described in Patent Document 1, the power necessary for controlling the DC stabilized power supply circuit or the power necessary for cooling is not proportional to the amount of load. is there.
For example, if the required power from the secondary battery is low and the rated output of the charging device is not required, if the required power is equally shared by all the power circuits and output, each power circuit operates at a low load. Will reduce efficiency. Further, when only a specific power supply circuit is frequently operated and stopped, there is a problem that the life of the power supply circuit is shortened and the life (repair cycle) of the entire charging device is shortened.
Note that Patent Document 1 does not specifically disclose how to select a plurality of DC stabilized power supply circuits to charge the secondary battery, and Patent Document 1 exclusively. It is assumed that a plurality of secondary batteries are charged.

  Therefore, a problem to be solved by the present invention is to provide a charging device that improves the efficiency and life of the entire device by controlling the outputs of a plurality of converters that charge one or more power storage devices in various patterns. There is.

In order to solve the above problems, the invention according to claim 1 is directed to a rectifier that converts AC power of an external AC power source into DC power, and DC / DC conversion of the output power of the rectifier to convert the output power from a common output terminal to a power storage device In a charging device comprising: a plurality of DC / DC converters to be supplied; and a control device that controls the converter to charge the power storage device,
The control device controls each converter so that the output of some of the plurality of converters is different from the output of other converters.

  According to a second aspect of the present invention, in the charging device according to the first aspect, the control device stops the operation of at least one of the plurality of converters.

  According to a third aspect of the present invention, in the charging device according to the first or second aspect, at least one of the plurality of converters is overloaded by the control device.

  The invention according to claim 4 is the charging device according to any one of claims 1 to 3, wherein the control device controls the output of each converter so that the efficiency of the entire charging device is maximized. It is.

  The invention according to claim 5 is the charging device according to any one of claims 1 to 4, wherein the ambient temperature of each converter, the internal temperature, or the temperature of the semiconductor element incorporated in each converter is detected, The said control apparatus calculates | requires the availability of the overload operation of each converter, an overload operation amount, and the output reduction amount based on detected temperature, and controls each converter.

  According to a sixth aspect of the present invention, in the charging device according to any one of the first to fifth aspects, the control device controls the converters to operate with a wheel number.

  The invention according to claim 7 is the charging device according to any one of claims 1 to 6, wherein the control device controls the converter to be preferentially operated with a short cumulative operation time. is there.

  According to an eighth aspect of the present invention, in the charging device according to any one of the first to sixth aspects, the control device is preferentially based on life determination data calculated from an output current and an operating time of each converter. The converter to be operated is determined.

  The invention according to claim 9 is the charging device according to any one of claims 1 to 6, wherein the control device controls the converter having a small integrated power amount to operate preferentially. is there.

  According to a tenth aspect of the present invention, in the charging apparatus according to any one of the first to sixth aspects, the control device is preferentially based on life determination data calculated from an ambient temperature and an operation time of each converter. The converter to be operated is determined.

  The invention according to claim 11 is the charging device according to any one of claims 1 to 6, wherein the control device is an electrolytic capacitor calculated from an ambient temperature and a ripple current of the electrolytic capacitor provided in each converter. The converter to be preferentially operated is determined based on the lifetime determination data.

According to the present invention, the output of each converter is controlled so that the output of some of the converters that charge the power storage device is different from the output of other converters (some By including the operation stop of the converter), it is possible to reduce the possibility that a plurality of converters break down almost simultaneously. In addition, if a control is performed so that the frequency of use of each converter is equalized based on a wheel drive operation or various life judgment data, it is possible to prevent a failure of a specific converter.
In general, according to the present invention, the lifetime of the entire apparatus can be extended, and the efficiency can be improved.

It is a block diagram of the ground charging apparatus for electric vehicles which concerns on 1st Embodiment of this invention. It is a block diagram which shows the modification of 1st Embodiment of this invention. It is a block diagram of the ground charging apparatus for electric vehicles which concerns on 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a ground charging apparatus for an electric vehicle according to a first embodiment of the present invention. The present invention can be applied not only to secondary batteries mounted on electric vehicles, but also to charging secondary batteries mounted on so-called hybrid vehicles and engine vehicles, secondary batteries for portable power supplies, and the like. Further, it can be applied not only to secondary batteries but also to various power storage devices including electric double layer capacitors.

  In FIG. 1, 10A is a ground charging device for an electric vehicle. This charging device 10A includes a rectifier (AC / DC converter) 11 having an AC side connected to an external AC power supply 20, a plurality of DC / DC converters 12 connected in parallel to each other on the DC side, and a conversion between them. And a control device 13 that generates an operation command or an output command for the device 12 as a control output. Here, the DC / DC converter 12 is configured by, for example, a chopper, and the number of converters 12 connected in parallel is not limited to the illustrated example, and may be any plural number.

Reference numeral 30 denotes an electric vehicle vehicle on which a secondary battery 31 as a power storage device to be charged is mounted. The secondary battery 31 is connected to a common output terminal of the plurality of DC / DC converters 12 using a cable or the like at the time of charging.
The vehicle 30 is provided with an information processing device (not shown) such as a microcomputer having a wireless or wired communication function. From this information processing device, information such as the terminal voltage of the secondary battery 31, a charging request command, etc. Is transmitted to the control device 13.
Note that there may be a plurality of secondary batteries 31 (that is, a plurality of vehicles 30), and in that case, via an appropriate switch on the output side of the DC / DC converter 12 in the charging device 10A ′, For example, the connection may be made as in the modification shown in FIG. Here, in FIG. 2, the control device is omitted for convenience.

Next, the operation of the first embodiment shown in FIG. 1 will be described.
For example, the charging device 10A is configured by connecting four DC / DC converters 12 with an output of 12 [kW] in parallel, and the rated output of the entire charging device 10A is 48 [kW]. Various operation methods of the charging apparatus 10A at this time will be described below.

  First, as the first driving method, when the charging power required from the vehicle 30 (secondary battery 31) is 30 [kW], the outputs of the four converters 12 are all equal to 7.5 [kW]. For example, by outputting 12 [kW] from the two converters 12 and outputting 3 [kW] from the remaining two converters 12 respectively, a total of 30 [kW] ] Output is obtained.

  As a second operation method, when the charging power required from the secondary battery 31 is 30 [kW], the outputs of the four converters 12 are not equally distributed as 7.5 [kW]. For example, 12 [kW] is output from each of the two converters 12 and 6 [kW] is output from another converter 12 to stop the operation of the remaining one converter 12. Thus, a total output of 30 [kW] is obtained.

  As a third operation method, when the charging power required from the secondary battery 31 is 30 [kW], the outputs of the four converters 12 are not equally distributed as 7.5 [kW]. For example, by outputting 15 [kW] above the rating from the two converters 12 capable of overload operation (that is, overload operation) and stopping the remaining two converters 12, A total output of 30 [kW] is obtained.

  In the first to third operation methods, the control output (operation command, output command, etc.) sent from the control device 13 to each converter 12 is appropriately changed to control the semiconductor switching element of each converter 12. Therefore, it can be easily realized.

As described above, in the first to third operation methods, the output of each converter 12 is not converted to another conversion with respect to the charging power required from the secondary battery 31, without equalizing the output of each converter 12. The output of each converter 12 is unbalanced by making it different from the output of the converter.
As a result, the degree of wear of the semiconductor switching elements and electrolytic capacitors incorporated in each converter 12 varies, so that the risk of failure of a plurality of converters 12 at the same time can be reduced. Reliability and stability can be improved. Even if some of the converters 12 fail in the future, it is possible to continue charging using another healthy converter 12.

Next, as a fourth operation method, the input power and output power of each converter 12 are measured, and the output of each converter 12 is adjusted so that the overall efficiency of the charging apparatus 10A is maximized.
For example, the input power and output power are calculated from the input and output voltages and currents of each converter 12 in the control device 13 to obtain the efficiency, and within the range satisfying the required power of the secondary battery 31, the charging device 10A A predetermined converter 12 may be selected and its output controlled to maximize the overall efficiency.
Alternatively, an efficiency characteristic map of each converter 12 may be stored in advance in the control device 13, and an operation state that maximizes the overall efficiency of the charging device 10A may be determined according to this map.
According to this operation method, even when the efficiency of the plurality of converters 12 varies, the charging device 10A as a whole can be charged with high efficiency.

As a fifth operation method, the ambient temperature, internal temperature, or semiconductor switching element temperature of each converter 12 is detected, the converter 12 having a low detection temperature increases the output, and the converter 12 having a high detection temperature outputs the output. The control device 13 creates and controls an operation command and an output command so as to decrease.
In this case, a temperature-output characteristic map of each converter 12 is stored in the control device 13 in advance, and according to the map, whether or not each converter 12 can be overloaded, the overload operation amount (rated value) when possible. Output) and output reduction (output less than the rated value).
According to this operation method, for example, the burden of the converter that is lossy or overheated due to overload operation can be distributed to other converters, and the failure of the converter can be prevented and the entire charging device 10A can be prevented. Efficiency can also be improved.

As a sixth operation method, the operation order is determined in advance for all the converters 12 and stored in the control device 13. That is, each converter 12 is operated with a wheel number.
Then, the control device 13 records the converter 12 that has been operated, and performs control so that the next converter 12 is operated in the next operation. For example, when there are two converters 12 built in the charging device 10A, alternate operation is performed, and when there are three or more converters 12, rotary operation is performed.

As a seventh operation method, the operation time of each converter 12 is recorded in the control device 13, and control is performed so that the converter 12 with a short accumulated operation time is operated with priority.
As an eighth operation method, the output current time product (output current I × operation time t, I ² × t, etc.) of each converter 12 is recorded in the control device 13 as life judgment data, and the current time product is calculated. Control is performed so that the small converter 12 is operated with priority.
Further, as a ninth operation method, the integrated power amount (output power W × operation time t) of each converter 12 is recorded in the control device 13 as life determination data, and the converter 12 having a small integrated power amount is recorded. Control to give priority to driving.

As a tenth operation method, the ambient temperature time product (ambient temperature T _a × operation time t) of each converter 12 is recorded in the control device 13 as life judgment data, and the converter having a small ambient temperature time product is recorded. Control is performed so that operation is performed with priority given to 12.

  As an eleventh operation method, the life judgment data of the electrolytic capacitor calculated from the ambient temperature and ripple current of the electrolytic capacitor included in each converter 12 is recorded in the control device 13, and the converter 12 having a long remaining life is recorded. Control is performed so that the vehicle is operated with priority. Here, the lifetime determination data may be obtained from an electrolytic capacitor manufacturer, for example.

  As described above, according to the sixth to eleventh operation methods, it is possible to prevent the use frequency of the specific converter 12 and concentration of duties and to prevent a decrease in the life thereof.

Next, FIG. 3 is a configuration diagram of a ground charging apparatus for an electric vehicle according to a second embodiment of the present invention.
In the charging device 10B according to this embodiment, a rectifier (AC / DC converter) 11 is connected between the input side of each DC / DC converter 12 and an external AC power supply 20, and the rectifier 11 and the converter are connected to each other. The power converter unit 14 is configured by 12.
Although the description is omitted to avoid duplication, the above-described first to eleventh operation methods can be applied also in the present embodiment.

10A, 10A ', 10B: Ground charger for electric vehicle 11: Rectifier (AC / DC converter)
12: DC / DC converter 13: Control device 14: Power converter unit 20: External AC power supply 30: Vehicle 31: Secondary battery

Claims (11)

A rectifier that converts AC power of an external AC power source into DC power, a plurality of DC / DC converters that DC / DC converts the output power of the rectifier and supplies it to a power storage device from a common output terminal, and the power storage device A control device for controlling the converter to charge the battery,
The controller is
A charging device that controls each converter so that an output of a part of the plurality of converters is different from an output of another converter. The charging device according to claim 1,
The charging device according to claim 1, wherein operation of at least one of the plurality of converters is stopped by the control device. The charging device according to claim 1 or 2,
A charging device, wherein at least one of the plurality of converters is overloaded by the control device. In the charging device according to any one of claims 1 to 3,
The said control apparatus controls the output of each converter so that the efficiency of the whole charging apparatus may become the maximum. In the charging device according to any one of claims 1 to 4,
Detecting the ambient temperature of each converter, the internal temperature, or the temperature of a semiconductor element built in each converter, the control device determines whether or not each converter can be overloaded, based on the detected temperature, A charging device that controls each converter by obtaining an output reduction amount. In the charging device according to any one of claims 1 to 5,
The said control apparatus controls so that each converter may be drive | operated by a wheel number, The charging device characterized by the above-mentioned. The charging device according to any one of claims 1 to 6,
The said control apparatus controls so that the converter with a short accumulation operation time may be operated preferentially. The charging device according to any one of claims 1 to 6,
The said control apparatus determines the converter operated preferentially based on the lifetime judgment data computed from the output current and operation time of each converter, The charging device characterized by the above-mentioned. The charging device according to any one of claims 1 to 6,
The said control apparatus controls so that the converter with small integrated electric energy may be operated preferentially. The charging device according to any one of claims 1 to 6,
The said control apparatus determines the converter operated preferentially based on the lifetime judgment data calculated from the ambient temperature and operation time of each converter, The charging device characterized by the above-mentioned. The charging device according to any one of claims 1 to 6,
The control device determines a converter to be preferentially operated based on life determination data of an electrolytic capacitor calculated from an ambient temperature and a ripple current of the electrolytic capacitor provided in each converter. .

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