Electricity: battery or capacitor charging or discharging – Serially connected batteries or cells – With individual charging of plural batteries or cells
Reexamination Certificate
2001-03-28
2002-05-28
Tso, Edward H. (Department: 2838)
Electricity: battery or capacitor charging or discharging
Serially connected batteries or cells
With individual charging of plural batteries or cells
C320S120000
Reexamination Certificate
active
06396244
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a combination battery having a plurality of power source elements or electric elements, to a battery system having a plurality of combination batteries, and to an electric element control apparatus. The present invention relates also to an inverter motor system in which a DC is converted into a polyphase AC in an inverter to drive a polyphase AC, in particular, to an inverter motor system having an electric element with an operating voltage different from that of a polyphase AC motor.
2. Description of the Related Art
Conventionally, combination batteries having a plurality of power source elements have been known. In conventional combination batteries, because it is difficult to ensure a larger unit output voltage for each power source element, a plurality of power source elements, each with a lower unit output voltage relative to a desired output voltage, are serially connected so that a desired output voltage can be ensured as a whole. An example of the above structure is disclosed in Japanese Patent Laid-open Publication No. Hei 7-322516.
In the above described art, however, because the power source elements are serially connected, when an output of any one of the connected plurality of power source elements drops due to functional deterioration or other reasons, an output voltage of the whole battery accordingly drops by an amount equivalent to the drop in output of that power source element. In addition, in systems where an operational voltage of an auxiliary of an battery system differs from an output voltage of the battery of the battery system, a separate DC/DC converter must be provided.
Also, an inverter motor system for driving an electric vehicle, as shown in
FIG. 10
, has conventionally been known as one type of inverter motor system as described above. This system
200
, which drives a vehicle driving motor via an inverter using a high voltage source, comprises an auxiliary
252
and an auxiliary power source
252
, the operating voltage of both of which differs from that of a polyphase AC motor
240
. As the voltage required by the auxiliary is lower than a vehicle driving voltage, a voltage from a high voltage source
210
is once reduced in a DC/DC converter
230
, to which an auxiliary power source and the auxiliary are connected. With such a structure, system volume and weight increase, as does power loss, because of the use of a DC/DC converter. In order for this system to be connected to a plurality of additional electric elements with different operating voltages, additional DC/DC converter or converters must be provided to the element with different operating voltage, resulting in a further increase of system volume, weight, and power loss.
A system enabling an auxiliary power source to be connected to a high voltage source without a DC/DC converter is disclosed in the form of an electric system for an electric vehicle in Japanese Patent Laid-open Publication No. Hei 11-178114. In the system disclosed in that publication, an auxiliary power source is connected between a motor neutral point, where ends of a plurality of windings of a motor are connected to one another, and a lower voltage side of a high voltage source. This system structure enables system volume and weight to be reduced through elimination of a DC/DC converter.
However, in this system, the operating voltage of the connected electric element or elements must remain within a constant range because an auxiliary power source, serving as an electric element, is simply connected to the motor neutral point. Therefore, it is difficult to improve operational efficiency of an electric element which varies its operating state, depending on the varying operating state. Moreover, connection of a plurality of electric elements with different operating voltages requires a DC/DC converter. That is, the system voltage and weight are increased, as is power loss.
SUMMARY OF THE INVENTION
The present invention has been conceived in view of the above. According to the present invention, there is provided an electric element control apparatus according to the present invention, comprises a charge-storage element; a neutral point selectively connected to either a higher voltage side or a lower voltage side of the charge-storage element via a selection switch; a plurality of electric elements connected between the neutral point and either the higher voltage side or the lower voltage side of the charge-storage element, each electric element generating, consuming, or storing electric power; and a selection switch control section for controlling switching of the selection switch to thereby control potential at the neutral point. The thus structured electric element control apparatus can control operation of a plurality of, or a plurality of types of electric elements through control of the potential at the neutral point. This makes it possible to simplify the structure of an apparatus compared to an apparatus wherein a control mechanism is provided for each electric element.
According to another aspect of the present invention, there is provided a battery system. The battery system comprises serially connected combination batteries. This structure enables reduction of an output voltage required to each combination battery included in the battery system, relative to the entire output voltage of the battery system, so that accuracy in controlling an output of each battery, and thus a battery system including the combination batteries, can be improved.
According to still another aspect of the present invention, there is provided a combination battery, comprising a charge-storage element; a plurality of power source units connected in parallel to the charge-storage element, each including a power source element for outputting electric power; and an open/close switch connected to the power source element, for controlling a current passing through the power source unit by switching itself; and an open/close switch control section for controlling switching of each open/close switch, wherein the combination battery outputs electric power stored in the charge-storage element. The combination battery outputs power stored in the charge-storage element. In addition, current to an electric element is controlled in a similar manner.
This structure can control input and output power for every power source element by controlling the open/close switch. Therefore, even when an output of, for example, one of the plurality of power source elements should drop, increasing outputs from the power source units excluding the one including the power source element with a dropped output can compensate the output loss due to the drop as a whole battery. That is, a battery output control can be achieved with improved accuracy.
In one aspect of the present invention, a combination battery may further preferably comprise a neutral point selectively connected to either a higher voltage side or a lower voltage side of the charge-storage element via a selection switch; and a selection switch control section for controlling switching of the selection switch. Preferably, the power source units are connected between the neutral point and either a higher voltage side or a lower voltage side of the charge-storage element. This structure enables easy and accurate controlling of a combination battery output through controlling of the potential at the neutral point.
In another aspect of the present invention, preferably, a combination battery may further comprise a pair of output terminals, one of which is connected to the neutral point and another is connected to either the higher voltage side or the lower voltage side of the charge-storage element. As the selection switch control section can control the potential at the neutral point to a desired value, as described above, the use of the neutral point as an output terminal allows use of the neutral point as a power source terminal for an external load.
In still another aspect of the present invention, a combination
Inaguma Yukio
Ishikawa Tetsuhiro
Komatsu Masayuki
Moriya Kazunari
Ohtani Hiroki
Oliff & Berridg,e PLC
Toyota Jidosha & Kabushiki Kaisha
Tso Edward H.
LandOfFree
Electric element control apparatus, battery system, and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electric element control apparatus, battery system, and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electric element control apparatus, battery system, and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2822594