[0001]The present invention relates to a battery system.
BACKGROUND
[0002]In electric vehicles, using a single species of the battery and supplies the electrical energy. As the battery capacity (Ah) performance capacity type battery with an emphasis on being used. However, the capacitive cells alone, a large current during acceleration and deceleration of the electric vehicle to flow, battery life because the load on the battery is applied tends to be shortened.
[0003]
　In contrast, the prior art is known as described in Patent Documents 1 and 2. In Patent Document 1, a power type battery with an emphasis on power performance, DCDC converter (DC - DC converter) via a configuration connected in parallel to the capacitive cell is disclosed. Further, Patent Document 2, is configured to be connected in parallel directly to the power battery to the capacitive cell is disclosed. Thus, by the combined energy storage system used in combination capacitive batteries and power batteries, power type battery share a steep current change, load capacity battery is reduced.
CITATION
Patent Document
[0004]
Patent Document 1: JP 2012-235610 Patent Publication
Patent Document 2: JP-A 11-332023 JP
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　In Patent Document 1, capacitive batteries, are directly connected to the inverter. In this case, within the operating voltage range of the capacitor battery, it is necessary voltage range of the inverter and the motor are housed. However, since the operating voltage range of the general capacity battery narrow, it is necessary to lower the torque constant of the motor (conversion constant torque and current), the motor characteristics is limited. Furthermore, lowering the torque constant, the regenerative voltage is lowered, the efficiency of the electric vehicle is reduced. Further, since the power battery is connected to DCDC converter, it is necessary to increase the power capacity of the DCDC converter, increases the cost of the DCDC converter.
[0006]
　In Patent Document 2, since there is no DCDC converter, the cost increase is suppressed although the capacity of the power battery is small, the electric energy of the power battery is reduced by the charging and discharging of a large current. Then, at an extent that can not share the charge and discharge capacity battery is forced to bear the charge and discharge current. The thus method of Patent Document 2 can not reduce the current capacity batteries in all conditions necessarily running, may not be reduced burden on the capacity type battery.
　The present invention, when used in combination power battery and capacity battery, to provide a composite power storage system can be shared appropriately to both battery charging and discharging current.
Means for Solving the Problems
[0007]
　Feature of the present invention for solving the above problems is as follows, for example.
　In capacitance-type battery and the power battery and a battery system constructed by connecting in parallel, voltage range of voltage range and power battery capacity battery has a portion in common, the current flowing through the capacitor battery response time and response time of the current flowing in the power battery of to be larger than the predetermined time, configured as a storage battery system configured by combining and a capacitance-type battery and the power battery.
[0008]
　Further, in the capacitor battery and the power battery and a battery system constructed by connecting in parallel, voltage range of voltage range and power battery capacity battery has a portion in common, the capacity battery as the ratio of the capacitance of the capacitor and the power battery is greater than a predetermined value, configured as a storage battery system configured by combining and a capacitance-type battery and the power battery.
Effect of the invention
[0009]
　According to the present invention, when used in combination power battery and capacity battery can provide a composite power storage system can be shared appropriately to both battery charging and discharging current. Other problems mentioned above, and advantages will become apparent from the following description of embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
[Figure 1] shows the a first embodiment of the composite power storage system and electric vehicle equipped with it configuration of the present invention.
It shows an electrical circuit model of the complex electric power storage system in the first embodiment of the present invention; FIG.
[3] in the electric circuit model of the complex electric power storage system in the first embodiment of the present invention, it shows an example of current characteristics of each battery for charging and discharging current.
[4] shows an example of the configuration conditions of the composite electric power storage system in the first embodiment of the present invention.
In the electric circuit model of the complex electric power storage system in Embodiment 2 of FIG. 5 the present invention, shows an example of current characteristics of each battery for charging and discharging current.
[6] shows an example of the configuration conditions of the composite electric power storage system in Embodiment 2 of the present invention.
[7] shows an embodiment which is 3 composite power storage system and configuration of an electric vehicle mounting the same according to the present invention.
[8] shows an example of a control flow of the composite power storage system according to a third embodiment of the present invention.
DESCRIPTION OF THE INVENTION
[0011]
　Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described. The following description shows a concrete example of contents of the present invention. Therefore, it is to be understood that the invention is not limited to these descriptions, but allows various variations and modifications by those skilled in the art within the technical scope disclosed herein. In all the drawings for describing the present invention, those having the same functions are given same symbols and their repeated explanation may be omitted.
Example 1
[0012]
　In the present invention, the power battery in parallel with the capacitor battery is connected. Capacity type battery and the power battery has overlap voltage range, the characteristics of each battery to be a predetermined time or more the response time predetermined current of the battery is determined with respect to current changes. Thus, despite the mounting of the minimum of the power battery, as compared with the case of using a capacitive cell alone, it can also be reduced in a variety of driving conditions the charge and discharge currents of the capacitor battery. Therefore, it is possible to lead to life improvement of capacity battery.
[0013]
　Figure 1 is a composite power storage system (battery system) according to a first embodiment of the present invention and shows the configuration of an electric vehicle mounting the same.
　As shown in FIG. 1, the electric vehicle 10 is provided with a power battery 13, a composite power storage system including a capacitive type battery 14 connected in parallel to the power battery 13. Combined power storage system via the inverter 12 are connected to motor generators 11. The inverter 12, the power battery 13, capacitive type battery 14 is controlled by a (short for "ECU" is "Electronic Control Unit") ECU15. That, combined power storage system, an inverter 12, a power battery 13, capacitive type battery 14, ECU 15.
[0014]
　Here, the motor generator 11 is an AC motor, for example, an induction machine or a synchronous machine. Power battery 13 and the DC power is outputted from the capacitance-type battery 14 to the inverter 12.
　Inverter 12 converts the DC power supplied from the power battery 13 and capacitive type battery 14 to three-phase AC power. The three-phase AC power inverter 12 outputs the motor-generator 11 is rotated as a motor. As a result, the electric vehicle 10 is traveling.
　If only capacity type battery 14 is insufficient power supplied to the motor-generator 11, such as in the time of acceleration of the electric vehicle 10 from the power battery 13, power is supplied to the motor generator 11 via the inverter 12 .
[0015]
　In such as during deceleration or braking of the electric vehicle 10, i.e. at the time of regeneration of the motor generator 11, AC power generated by motor-generator 11 is converted to DC power by operating the inverter 12 as a rectifier. The converted power is the power battery 13 and is charged in the capacitor battery 14.
　During parking of the electric vehicle 10, capacitor battery 14 and the power battery 13 is charged by an unillustrated charging apparatus.
[0016]
　The motor-generator 11 in FIG. 1 may be constituted by a separate motor and generator, respectively.
　Power battery 13, rather than capacitive cell 14, excellent output density, but the capacity (Ah) is small. Examples of such a power battery 13, for example, such as a lithium ion battery or a nickel hydrogen battery is applied. In place of the power battery 13, a power storage device such as a lithium ion capacitor or an electric double layer capacitor having the same high output characteristics and which (so to speak, a power type power storage device) may be used. In the following, including these batteries and capacitors, collectively referred to as "power-type battery".
[0017]
　Capacitive cell 14, although than the power battery 13 power density is inferior, superior capacity (Ah) is large energy density. Such capacity type battery 14, a lithium ion battery, a lithium ion semisolid batteries, lithium solid state battery, lead battery, nickel-zinc battery is applied. Incidentally, a lithium ion battery used as a power battery 13, a lithium ion battery used as the capacitive cell 14, the configuration of such electrode materials are different.
　As described above, according to this embodiment, a combination of power battery 13 and capacitive cell 14, the entire cell using, and increasing the battery output while ensuring battery capacity to ensure cell output while it is also possible, and increasing the battery capacity.
[0018]
　However, the power battery 13 and the capacitor battery 14 is connected without passing through the current control element such as a DCDC converter. Then, during charge and discharge current is uniquely determined by the characteristics of the power battery 13 and the capacitor battery 14. Therefore, the combination of these properties has to battery system combines optimally to produce the desired properties. The reason will be described with reference to FIG.
[0019]
　Figure 2 is a diagram that models the state of the power battery 13 and the capacitor battery 14 is connected in parallel. The variation of the voltage of the battery due to charging and discharging simulated by a capacitor unit, simulating the resistance of the battery in an electric resistance. Left cell represents the power battery 13, the electrical resistance R 1 , the capacitance C 1 and. Capacitance right cell indicates a capacitive cell C 14 2 = mC 1 , DCR (direct current resistance component), R 2 = nR 1 to. The initial battery voltage, that charge state and V (0), as the total current I of the power battery 13 and the capacitor battery 14, which is a power battery 13 and capacitive cell 14 each voltage when changing the following ( can be expressed by equation 1) and (equation 2).
[0020]
[Number 1]

[0021]
[Number 2]

[0022]
　Furthermore, by modifying the above equation, each current of the power battery 13 and the capacitor battery 14 can be expressed by the following equation (Equation 3) and (Equation 4).
[0023]
[Number 3]

[0024]
[Formula 4]

[0025]
　(Equation 3) based on the equation and Equation (4) shows the response of the power battery 13 and the capacitor battery 14 when the current is changed stepwise in Fig. At time t = 0 just after the current has changed, the power battery 13 (i 1 ) and capacitive cell 14 (i 2 current of) The current changes over time, in a state where sufficient time has elapsed the current is distributed according to the ratio of capacity. Of the time from initial until the current converges, the time to reach 63.2% of the convergence value of the current is called the response time, (Equation 3) and the formula from that value the following equation (4) ( the equation 5).
[0026]
[Formula 5]

[0027]
　As apparent from FIG. 3, if the response time is short, initial power battery 13 (i 1 but) will bear a lot of current, the effect is a thing of the instantaneous or short time, mostly capacitive the battery 14 (I 2 ) is to bear. Therefore, when a vehicle travels equipped with a response time shorter composite power storage system to an electric vehicle, the charge and discharge Naru requirement of a large current during acceleration or deceleration regeneration, although the power battery 13 to bear the instantaneously current , most of the current is becomes the capacity type battery 14 will bear. From the above, in order to reduce the burden of the capacitive cell 14, assume the regeneration at the time of acceleration or deceleration of a large current is required, the length of the response time such therebetween current power battery 13 can be borne it is necessary to previously consider. In other words, as the response time of the current flowing in the response time and power battery 13 of a current flowing through the capacitor battery 14 is greater than the predetermined time, are combined and the capacity type battery 14 and the power battery 13 structure It is.
[0028]
　In this embodiment, the calculation result as a suitable value of the response time (Equation 5) has a larger conditions than 60 seconds, not limited to this value. Further, the definition of the response time is not limited to 63.2% according to the present invention, it may be 90% as an example.
[0029]
　Figure 4 illustrates in building composite cell system, the voltage range of the series connection of the power battery and capacity battery as the other conditions. Reference numeral 41 of FIG. 4 shows the voltage range of the power battery 13 (a value obtained by multiplying the number of series in the unit cell case of series connection) (power battery voltage range × power battery series number). Further, reference numeral 42 is a capacitive cell 14 using voltage range is (capacitive battery voltage range × capacity battery series number) that shows the. As shown in FIG. 4, voltage range 42 of the series connection of voltage range 41 and the capacitor battery 14 of the series connection of the power battery 13, configured to overlap. In other words, voltage range 41 of operating voltage range 42 and the power battery 13 of the capacitive cell 14 has a portion in common. This is because, if the overlap is not, because it is always the charging current flows to a low battery from the high voltage battery, it is hard for the functioning composite cell system. Overlap Availability voltage width (43), "the upper limit of the overlap usable range (44) - overlap usable range lower limit (45)" as a battery to a voltage range and use of the power supply target while considering the performance, as the voltage width is increased, the series number of the power battery 13 and capacitive cell 14 is determined.
Example 2
[0030]
　A method for increasing the current power battery 13 is borne (Example 2) will be described with reference to FIG. Combined power storage system and electric car configurations and circuit model for mounting it are the same as in Example 1.
　As described above, the convergence value of the current of the power battery 13 and the capacitor battery 14 during charging and discharging from the determined in accordance with the capacity ratio, in Example 2, volume ratio power battery: capacitive cell = 1: shows an example in which 2. That is, the convergence current value of the power battery 13, as shown in FIG. 5 (i 1 ) is I / 3, the convergence current value of the capacitor battery 14 (i 2 ) is adjusted such that 2I / 3. In other words, as the ratio of the capacitance of the capacitor and the power battery 13 of the capacitive cell 14 is greater than a predetermined value, and a capacitance-type battery 14 and the power battery 13 is configured by combining. In such embodiments, although a large capacity is required to power battery 13, regardless of the response time of the composite power storage system, it is possible to construct a composite cell system capable reducing the burden of the capacitive cell 14.
[0031]
　Figure 6 shows the condition in building composite cell system according to the second embodiment. As described in FIG. 4, for use in parallel connection of two batteries, it is necessary overlap the usable voltage range of each battery. Furthermore, in Example 2, the capacitance difference of the power battery 13 and the capacitor battery 14, the convergence value of the charge and discharge currents of each of the battery, so that an appropriate value, it is necessary to consider the capacitance difference. In Example 2, a power battery 13, as described in FIG. 5 as an example, a capacitance ratio of the capacitive cell 14 1: 2 and was, but not limited to this value.
Example 3
[0032]
　Figure 7 shows a third embodiment. Current basic configuration is the same as FIG. 1 in Example 1, to release the battery during capacitor battery 14 and the power battery 13 and the inverter 12, from the composite power storage system if an abnormality occurs in each of the battery blocking mechanism 16 is added to the configuration. As a result, even if an abnormality in either of the battery during the operation of complex power storage system occurs, the system can operate normally. Current interrupt device 16 may be connected to both the capacitor battery 14 and the power battery 13 as shown in FIG. 7, be connected only to either of the capacitive type battery 14 and the power battery 13 it may be.
[0033]
　Figure 8 is a control flow for the functioning of the system configuration of FIG. After system start (START; S800), S801 in ECU15 is measured voltage of the battery system, current, temperature information. Also, to estimate the SOC is charged state from the measurement information (data measurement, state estimation).
　In S802, the voltage of the power battery 13 and / or capacitive type battery 14, the temperature, at least one of the SOC is judged whether or not larger than a predetermined value the predetermined (predetermined value 1). ECU15, when there is no abnormality (NO), the program proceeds to S803, if there is an abnormality (YES), the process proceeds to S804.
　In S803, ECU 15 is the voltage of the power battery 13 and / or capacitive cell 14, at least one of the SOC is judged whether or not less than the predetermined value the predetermined (predetermined value 2). If there is no abnormality (NO), ECU 15 repeats the flow from S801. If there is an abnormality (YES), ECU 15 proceeds to S804.
[0034]
　In S804, it determines whether the abnormality in the capacitance-type battery 14 has occurred. S804 is the case of No S805 in ECU15 is released from the composite power storage system control to the current interrupt device 16 of the power battery 13. In other words, the parallel connection of the capacitor battery 14 and the power battery 13 by the current interrupt device 16 is released (the power battery 13 blocked). If S804 is YES, ECU 15 controls the current interrupt device 16 of the capacitive cell 14 in S806 to cancel the parallel connection of the composite power storage system (capacity type battery 12 blocked). Then, later, ECU15 repeats the flow from S801.
DESCRIPTION OF SYMBOLS
[0035]
10 electric vehicle
11 motor generator
12
inverter, 13 power battery
14 capacity type battery
15 ECU
16 current interrupt device

WE CLAIM

In battery system configured by connecting a capacitor battery and the power battery in parallel,
　voltage range of the power battery and voltage range of the capacitor battery has a portion in common,
　the capacitor battery battery system response time of the current flowing in the response time and the power battery of the electric current that is configured by combining and the like, the power battery and the capacitor battery is larger than the predetermined time flowing through.
[Requested item 2]
　In the battery system of claim 1,
　as the response time of the current flowing in the response time and the power battery of the electric current flowing through the capacitor battery is greater than 60 seconds, and the said power battery and said capacitor battery combined battery system being configured.
[Requested item 3]
　In the battery system of claim 2,
　wherein the capacitive cell and the power battery is a storage battery system that satisfies the following (Equation 1).
　m (n + 1) C 1 R 1 / (m + 1) ≧ 60 · · · (Equation
　1) m: Capacity battery and the capacitance ratio of the power battery (capacity type battery / power
　battery) n: Capacity battery and powered resistance ratio of the battery (capacity type battery / power battery)
　C 1 : power battery capacity
　R 1 : powered resistance value of the battery
[Requested item 4]
　In battery system configured by connecting a capacitor battery and the power battery in parallel,
　voltage range of the power battery and voltage range of the capacitor battery has a portion in common,
　the capacitor battery capacity and the power-type ratio of the capacity of the battery so that is larger than a predetermined value, the battery system of said power battery and said capacitor battery is configured by combining the.
[Requested item 5]
　In any of the storage battery system of claims 1 to 4,
　wherein the battery storage system includes a power cutoff mechanism,
　a storage battery system wherein the capacity battery or the power interruption mechanism to the power battery is connected.
[Requested item 6]
　In the battery system of claim 5,
　wherein the capacitor battery or when an abnormality occurs in the power battery, the battery system for parallel connection with the power battery and said capacitive cell is released by the power cutoff mechanism.
[Requested item 7]
　In the battery system of claim 6,
　wherein the capacitance-type battery or the voltage of the power battery, temperature, when at least one of the SOC is greater than a predetermined value, and the power battery and the capacitor battery by the power interruption mechanism battery system that parallel connection of is released.
[Requested item 8]
　In the battery system of claim 6,
　wherein the capacitance-type battery or the voltage of the power battery, at least one of the SOC, is smaller than a predetermined value, and the power battery and the capacitor battery by the power interruption mechanism battery system that parallel connection is released.