JP6971666B2 - Combined power storage system and control method of compound power storage system - Google Patents

Description

The present invention relates to a composite system of batteries that supply electric power to an electric load, and particularly relates to a technique that is effective when applied to a storage battery of an electric vehicle.

Electric vehicles (EVs) use a single battery to supply the energy to drive the vehicle's electric motor. Generally, this battery uses a battery that emphasizes capacity (Ah) performance in consideration of mileage.

However, in recent years, electric vehicles of various vehicle types have become widespread, and there may be cases where the power of the battery is insufficient with the battery alone that emphasizes capacity performance. In addition, the life of the capacitive battery may be shortened. Therefore, a composite system that combines a plurality of batteries having different characteristics has been proposed.

As a background technology in this technical field, for example, there is a technology such as Patent Document 1. Patent Document 1 discloses "a charge / discharge control device that shares power in a charge / discharge system provided with power storage devices having different characteristics".

Further, Patent Document 2 discloses "a power storage system that prolongs the life of a lead battery by increasing the charging voltage of the lead battery while maintaining the rated voltage of the electric load".

Japanese Unexamined Patent Publication No. 2016-152718 International Publication No. 2015/060139

By the way, as a power type battery of an electric vehicle (EV), a 48V battery pack or a 300V battery pack used in a hybrid vehicle (HV) may be diverted, but the voltage range of the electric vehicle (EV) is hybrid. It can often be different from the voltage provided in the vehicle (HV) (eg 52V).

In this case, the power type battery pack prepared in the hybrid vehicle (HV) cannot be used as it is, so it is necessary to use a DCDC converter or create a new power type battery pack.

The above-mentioned Patent Document 1 describes a charge / discharge control device including two power storage devices having different characteristics and calculating the share ratio of the other power storage device based on the charge rate of the other power storage device. Differences in voltage specifications such as are not taken into consideration.

On the other hand, Patent Document 2 describes a technique for attaching a DCDC converter and a lead battery to a power type battery pack having a lower potential. According to Patent Document 2, by attaching a DCDC converter and further connecting a battery installed in an existing vehicle such as a lead battery, it is possible to cope with a voltage such as a 52V vehicle. In addition, since the DCDC converter is connected to the bottom, the power of the DCDC converter is reduced, and the heat generation and SW withstand voltage are reduced, resulting in a low-cost DCDC converter.

However, in Patent Document 2, when connecting a DCDC converter, the charge rate SOC (State of Charge) of the power type battery pack deviates depending on the output voltage range of the DCDC converter, or the capacity type batteries connected in parallel are always used. There is a risk of discharging to the power type battery side.

Therefore, an object of the present invention is a composite power storage system in which a power type battery that emphasizes power performance and a capacity type battery that emphasizes capacity performance are connected in parallel, and can be mounted on electric vehicles (EVs) of various vehicle types at low cost. The purpose is to provide a complex power storage system.

In order to solve the above problems, the present invention presents a power type battery pack and a bidirectional step-up DCDC converter connected to a terminal opposite to the terminal of the power type battery pack connected in parallel with the capacity type battery. A second battery connected to a terminal opposite to the terminal connected to the power type battery pack of the bidirectional step-up DCDC converter.

Further, the present invention is a control method of a composite power storage system in which a power type battery pack that emphasizes power performance and a capacity type battery that emphasizes capacity performance are connected in parallel, and (a) from the battery controller of the capacity type battery. Corresponds to the current charge rate of the capacitive battery based on the steps of receiving the charge rate, total voltage and current, (b) estimating the demand current, and (c) the open circuit voltage characteristics of the capacitive battery. A step of calculating the open circuit voltage, (d) a step of calculating the total open circuit voltage of the power type battery pack corresponding to the central charge rate of the power type battery pack, and (e) presetting in the electronic control device. A command voltage is transmitted to the controller of the DCDC converter based on the step of calculating the output voltage of the DCDC converter based on the values of the set target resistance and the target capacitance and (f) the output voltage calculated in the step (e). It is characterized by having a step and.

According to the present invention, in a composite power storage system in which a power battery that emphasizes power performance and a capacity battery that emphasizes capacity performance are connected in parallel, a composite that can be mounted on electric vehicles (EVs) of various vehicle types at low cost. A power storage system can be realized.

Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

It is a figure which shows the system configuration of the electric vehicle equipped with the composite power storage system which concerns on one Embodiment of this invention. It is a figure which shows the structure of the battery part of the composite power storage system which concerns on one Embodiment of this invention. (Example 1) It is a figure which shows the structure of the DCDC converter of the composite power storage system which concerns on one Embodiment of this invention. It is a figure which shows the correlation of each OCV of the capacity type battery and the power type battery pack of the composite power storage system which concerns on one Embodiment of this invention. It is a figure which shows the voltage conversion example of the power type battery pack of the composite power storage system which concerns on one Embodiment of this invention. It is a flowchart which shows the sequence of the ECU of the composite power storage system which concerns on one Embodiment of this invention. It is a figure which shows the structure of the battery part of the composite power storage system which concerns on one Embodiment of this invention. (Example 2) It is a figure which shows the structure of the battery part of the composite power storage system which concerns on one Embodiment of this invention. (Modified example of Example 2)

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals, and the detailed description of the overlapping portions will be omitted. Further, the present invention is not limited to the following embodiments, and various modifications and applications are included in the technical concept of the present invention. For example, the examples described below can also be applied to building management systems, plug-in hybrid vehicles, hybrid vehicles, ships, railways, electric airplanes, and the like.

A control method for the composite power storage system and the composite power storage system according to the first embodiment will be described with reference to FIGS. 1 to 6. FIG. 1 shows a system configuration of an electric vehicle equipped with the combined power storage system of this embodiment. FIG. 2 shows the configuration of the battery unit 13 in FIG. 1, and FIG. 3 shows the configuration of the DCDC converter 22 in FIG. FIG. 4 is a diagram showing the correlation between the open circuit voltage OCV (Open Circuit Voltage) of each of the capacity type battery and the power type battery pack of the composite power storage system. FIG. 5 is a diagram showing an example of voltage conversion of a power type battery pack. Further, FIG. 6 is a flowchart showing the sequence of the ECU 14 of FIG.

As shown in FIG. 1, the electric vehicle 10 equipped with the composite power storage system of the present embodiment has a motor generator 11, an inverter 12, a battery unit (storage battery) 13, and an ECU 14 (electronic control device) which is a host controller, as main configurations. : Electronic Control Unit), includes a communication line 15 for exchanging information between the ECU 14, the battery unit 13, and the inverter 12.

The electric vehicle 10 supplies electric power from the battery unit 13 to the inverter 12 during traveling, and rotates and drives the motor generator 11 to travel. On the other hand, at the time of regeneration, the electric power generated by the motor generator 11 is rectified by the inverter 12 and charged to the battery unit 13. Although the electric vehicle 10 of FIG. 1 has a configuration in which the motor and the generator are shared (the same one is used), the electric motor and the generator may be separately provided.

Next, the configuration of the battery unit (storage battery) 13 will be described with reference to FIG. The battery unit 13 is composed of a power type battery pack 21, a DCDC converter 22, a second battery 23, and a capacity type battery (capacity type battery pack) 24 for maintaining sustainability.

As the capacity type battery 24, an olivine iron lithium ion battery or a nickel / manganese / cobalt lithium ion battery mounted on an existing electric vehicle (EV) may be used, or a semi-solid lithium ion battery or lead may be used separately. A battery, a nickel hydrogen battery, a fuel cell, a primary battery, or the like may be used. Further, the power type battery pack 21 and the DCDC converter 22 may be integrated. As the second battery 23, a 12V lead battery mounted on an existing electric vehicle (EV) may be used, or a battery may be prepared separately. Further, the DCDC converter 22 may be a bidirectional DCDC converter using a bidirectional step-up chopper. As a configuration example of the bidirectional boost chopper, the configuration as shown in FIG. 3 described later may be used.

The configuration of the DCDC converter 22 will be described with reference to FIG. As shown in FIG. 3, the DCDC converter 22 connects 32 terminals (power type battery pack GND terminal connection terminal 32) to the GND terminal of the power type battery pack 21, and 34 terminals (34 terminals) to the + terminal of the second battery 23. Connect the second battery + terminal connection terminal 34). The DCDC converter 22 has a control circuit 35, which controls the voltage of the terminal 32 or the voltage of the terminal 34, and controls the current sensor 31 that measures the current flowing from the power type battery pack 21 to the command value (value from the ECU 14). Or, the value of the current sensor 33 that measures the current flowing through the second battery 23 is controlled to the command value (value from the ECU 14).

Here, the current sensor 31 may be provided in the power type battery pack 21, and it is not always necessary to provide the current sensor 31 if it can be estimated from the current sensor 33 on the second battery side and other voltage information. Similarly, the current sensor 33 does not necessarily have to be provided if it can be estimated from other voltage information or current information.

Next, the voltage / current balance of FIG. 2 will be described with an example in which the power type battery pack 21 has a rating of 48 V, the second battery 23 has an existing 12 V lead battery, and the capacity type battery 24 has a rating of 52 V. In this case, since the power type battery pack 21 (48V) is 4V short of the capacity type battery 24 (52V), the DCDC converter 22 supplements 4V (about 3V to 4V). This 4V energy source is supplemented by stepping down a 12V lead battery with a DCDC converter 22.

The reason why the DCDC converter 22 is mounted under the power type battery pack 21 is that the voltage applied to the DCDC converter 22 can be lowered to lower the power specification of the DCDC converter 22 compared to when 52V is supported, and the transistor in the DCDC converter 22 can be lowered. This is to reduce the power loss of the switch, simplify the heat dissipation design, and reduce the cost.

Assuming that 150A is required as the peak current as the current required for the power type battery pack 21, the 12V lead battery (second battery 23) can only handle the charging / discharging current of 150A instantaneously. .. However, since the DCDC converter 22 boosts the voltage from 4V to 12V, the current is about 1/3 of 50A, and the 12V lead battery (second battery 23) can handle charging and discharging of 50A for 1 minute or more. Here, the DCDC converter 22 and the power type battery pack 21 may be integrated.

The above voltage / current balance is an outline, and as a practical matter, the output voltage terminal (power type battery pack + terminal) 25 of the capacity type battery pack 24 and the power type battery pack 21 are the same, and here the capacity type battery pack 24 The open circuit voltage OCV (Open Circuit Voltage) and the OCV of the power type battery pack 21 do not always match, and a current is generated from the power type battery pack 21 to the capacity type battery pack 24, which is a so-called cross current. This cross current is recommended in terms of regenerating an electric vehicle (EV) and supplying energy from the capacity battery pack 24 to the power battery pack 21 (or vice versa) during power running, constant running, or when the vehicle is stopped. It is not preferable in terms of safety that a constant current always flows from the capacity type battery pack 24 to the power type battery pack 21 because it causes overcharging and overdischarging. Therefore, the voltage control in consideration of the safety of the battery in the DCDC converter 22 will be described.

First, the OCV of the total capacity type batteries shown in FIG. 4 (that is, the value obtained by multiplying the OCV per battery by the number of series of capacity type batteries) -SOC (State of Charge) curve and the OCV of the total power type batteries (that is, that is). The value obtained by multiplying the OCV per battery by the number of batteries in the power type battery pack 21) -SOC curve will be described as an example. The characteristic of this OCV is a virtual battery. Here, the capacity type battery shall be used in the range of SOC 5% to 95%. From the viewpoint of preventing deterioration, it is assumed that the power type battery is used in the range of SOC 30% to 70%. Furthermore, it is desirable to keep the power type battery in the state of SOC 50%. This is because there is regenerative power running, so the normal state is returned to SOC 50% and there is a margin.

In the example of FIG. 4, from the power type battery pack SOC range 46, the lower limit SOC of the power type battery pack is the value of reference numeral 43. This value is larger than the OCV when the capacity type battery SOC is 5%, and as a result, the lower limit SOC44 of the capacity type battery is larger than 5%, and the usable SOC range 45 of the capacity type battery is limited, from the initial 5% to 95. It becomes narrower than the% range, and the mileage of the electric vehicle (EV) becomes shorter.

In such a case, the voltage of the DCDC converter 22 may be set as Equation 1. This is because, in the steady state, the voltage of the power type battery is maintained at OCV at 50% SOC, and the SOC of the power type battery converges to 50%. In this case, cross currents occur transiently during regeneration and power running, and then transiently, but then the SOC of the power battery automatically returns to 50%. Although the SOC is 50% in Equation 1, it may be, for example, 60% or the SOC value in the allowable range of the power type battery (for example, 40%).

For the SOC of the capacitive battery in Equation 1, if the SOC is flowing through the communication line 15, that value is used. Next, the OCV of the capacity type battery is held at a table in the control circuit 35 of the ECU 14 or the DCDC converter 22, and the value is obtained from the SOC of the capacity type battery. The SOC of the power type battery pack 21 uses the value flowing through the communication line 15 from the power type battery pack 21, and the total OCV of the power type battery pack 21 is similarly in the control circuit 35 of the ECU 14 or the DCDC converter 22. Hold it at the table and find the value from the SOC of the power battery.

In this case, the + terminal 25 of the power type battery pack is only the voltage source connected to the original power type battery pack 21, so that the internal impedance seen from the + terminal 25 of the power type battery pack is the original power type battery pack 21. Will be the same as. Here, the internal impedance of the power type battery pack 21 increases due to deterioration, and the capacity [Ah] decreases. In this case, as a transient phenomenon of regeneration or power running, the current flowing through the power type battery becomes small, the load on the capacity type battery becomes large, and the life of the capacity type battery may be shortened. In this case, the voltage may be specified by the DCDC converter 22 as in Equation 2 so as not to be affected by the deterioration of the power type battery, the manufacturing variation, and the model number variation.

For R (target resistance) and C (target capacitance), constants predetermined at the time of shipment from the factory may be input. The initial setting method of R and C will be described. This is basically a design concept in which the load is shared by the power type battery in regeneration and power running. From this, the high frequency must be shared by the power type battery. Here, assuming that the current demand applied to the entire battery pack is I, the currents to the power type battery pack 21 and the capacity type battery 24 are equations 3 and 4, respectively.

Since Z (AC impedance of capacitive battery) indicates DC resistance and diffusion, Z (∞) = r0 (DC resistance) and Z (0) = R∞ (resistance at constant current and t = ∞). ). From this, the cutoff frequency fc is approximately 1 / 2πC (r0 + r). A frequency higher than fc will flow to the power type battery pack 21. For example, fc may be set to 0.1 Hz in consideration of regenerative power running. In this case, when r0 is measured and, for example, the total capacity type battery is 10 mΩ, C = 1 / (2π × 10 ^ -2 × 0.1) ≈160 [F] may be set.

Further, since it is a DCDC converter 22, it can be designed so that R = 0. When R = 0, the differential characteristic of the current flowing through the capacitive battery can be set to 0 (that is, the current flowing through the capacitive battery is equivalent to applying the low-pass filter of I), so R = 0 in the DCDC converter 22. It may be controlled so as to be. In this case, it is equivalent to controlling "current of power type battery pack = current of ZC x d capacity type battery / dt", so the current flowing through capacity type battery is monitored and the current flowing through power type battery is monitored. May be controlled.

Next, the values of Z and C may be changed as the capacitive battery deteriorates. This is because when the capacitive battery deteriorates, the cutoff frequency changes and the current balance is lost, so Z and C are changed so as not to change the cutoff frequency. From Equations 3 and 4, if the resistance deterioration multiple of the capacitive battery is λ, then R may be multiplied by λ and C may be multiplied by 1 / λ.

In addition to Equation 2, a power-type battery OCV that is simply linearly converted "DCDC voltage = (A-1) x power-type battery total pack voltage + B" may be used. At this time, the constants A and B of the linear conversion are set so that the power type battery has a usage range of, for example, SOC 30% to 70% even at the voltage when the capacitive SOC becomes the lowest. This relationship is shown in FIG. FIG. 5 shows the OCV of the total capacity type battery (that is, the value obtained by multiplying the OCV per battery by the number of series of capacity type batteries) -SOC curve and the OCV of the total power type battery (that is, the power of the OCV per battery). (Value multiplied by the number of batteries in the mold battery pack) -This is an example of the SOC curve. The characteristic of this OCV is a virtual battery.

The original OCV51 of the power type battery pack in FIG. 5 cannot be used at the upper limit of the SOC of the capacity type battery. Therefore, in the OCV curve 52 in which A × power type battery pack voltage + B is set by the DCDC converter, the OCV at the upper limit of the SOC of the capacity type battery is larger than the upper limit of the SOC range 53 of the power type battery pack, so that it can be used. Since the capacity type battery usage lower limit SOC55 with respect to OCV54 with respect to the lower limit SOC of the power type battery is matched, the power type battery can be used even if the capacity type battery has the minimum SOC. This relational expression becomes equations 5 and 6.

When Equation 2 is used, R (target resistance) and C (target capacitance) are determined so that the output voltage of the DCDC converter 22 becomes positive. Also, when the power type battery voltage is linearly converted, A and B are determined so that (A-1) × power type battery pack voltage + B becomes positive.

The above is a method in which voltage is basically used for DCDC converter control, but current may be controlled. As the logic, regeneration / power running may be shared by the power type battery, and the insufficient power of the power type battery may be shared by the insufficient power to the capacity type.

The above is an example in which the 48V power type battery pack 21 and the 12V lead battery are used as the second battery 23, but the 48V battery pack may be used for the second battery 23. Further, although the output voltage is around 52V, if 72V is a voltage guideline for the capacitive battery 24, 72V may be produced by using two 48V battery packs as 48V battery packs for the second battery 23. .. Further, the bidirectional DCDC converter 22 may be a step-up type, and a battery having a low voltage may be used for the second battery 23.

The sequence operation in the ECU 14 will be described with reference to FIG. Here, DCDC converter control by Equation 2 is assumed.

First, in step 61, SOC, total voltage, and current are received from the battery controller of the capacitive battery.

Next, in step 62, the demand current I (calculated from the motor torque) is obtained. This value may be separately received from the inverter controller, or the required torque may be estimated from the accelerator opening of the electric vehicle (EV) to obtain the current. If the required current is estimated in the ECU 14, that value may be used.

Next, in step 63, the OCV corresponding to the current SOC of the capacity type battery is obtained from the OCV curve (table stored in advance) of the capacity type battery. The OCV here is the total OCV obtained by multiplying the OCV of one capacity type battery by the number of series of capacity type batteries.

Next, in step 64, the total OCV of the power type battery pack corresponding to the central SOC of the power type battery pack (50% in the above-mentioned example) is obtained. The OCV here may have the OCV of the power type battery as a table in advance.

Next, in step 65, the output voltage of the DCDC converter is determined from Equation 2 from the preset values of R (target resistance) and C (target capacitance). The capacity of the power battery pack in Equation 2 shall be obtained from the power battery pack controller when the ignition of the electric vehicle (EV) is turned on.

Finally, in step 66, a command voltage is sent to the controller of the DCDC converter to control the voltage of the DCDC converter. After the end of step 66, the process is returned to step 61 again in the control cycle (for example, 10 ms), and the process is repeated until the ignition of the electric vehicle (EV) is turned off.

Here, when the DCDC converter is controlled as "DCDC voltage = (A-1) x total pack voltage of power type battery + B", the total battery voltage of the power type battery is received in step 61, and the step is performed. 63 and 64 are omitted, and in step 65, the DCDC voltage may be determined as "DCDC voltage = (A-1) x total pack voltage of the power type battery + B".

If the DCDC converter is current-controlled, the SOC, total voltage, and current of the power-type battery are additionally received in step 61, steps 63 and 64 are omitted, and the current is used instead of step 65. It may be determined and the current of the DCDC converter may be instructed in step 66. As a method of determining the current, the current is borne only by the power type battery at the time of regeneration and power running. If the current is not enough for the power type battery due to regeneration and power running, the maximum current of the power type battery is given. When the SOC of the power type battery is equal to or less than a predetermined threshold value, a constant current (predetermined value) is charged in order to charge the power type battery.

The above is an example of an ECU, but it may be operated by a controller of a DCDC converter or a controller prepared separately instead of the ECU.

As described above, according to the present embodiment, an inexpensive battery (such as a 12V lead battery already installed in a car) can be used as the battery in the lower series of the DCDC converter of the power storage system, and the power type battery can be used. It can be adjusted to the voltage range of any electric vehicle (EV) at low cost without planning a new pack.

This makes it possible to realize a combined power storage system that can be installed in electric vehicles (EVs) of various vehicle types at low cost.

A control method for the composite power storage system and the composite power storage system according to the second embodiment will be described with reference to FIGS. 7 and 8. FIG. 7 is a modified example of the battery unit 13 described in the first embodiment (FIG. 2), and shows a balancing configuration when an existing 12V lead battery is used. FIG. 8 is a modification of FIG. 7, and shows a balancing configuration when a battery other than the existing 12V lead battery is used.

In the first embodiment described above, the currents of the power type battery pack 21 and the second battery 23 are different, so that the SOCs of the power type battery pack 21 and the second battery 23 may deviate from each other. In this embodiment, the SOC balancing method (control method) will be described.

First, a balancing method when an existing 12V lead-acid battery is used as the second battery 23 will be described with reference to FIG. 7. In FIG. 7, a 12V auxiliary device 71 (light, navigation, etc.) and a DCDC converter 72 for stepping down from 52V to 12V are added to the existing 12V lead battery (second battery 23). Here, basically, when the SOC of the 12V lead battery (second battery 23) is insufficient, the 12V lead battery (second battery 23) is charged by using the DCDC converter 72 that steps down from 52V to 12V. However, while the bidirectional DCDC converter 22 is charging / discharging by regeneration or power running, the operation of the DCDC converter 72 that steps down from 52V to 12V so as to balance charge / discharge to the 12V lead battery (second battery 23) is operated. Stop it or use only the power of the 12V auxiliary machine 71.

As this sequence, the ECU 14 determines whether it is regenerative or power running, and if it is regenerative or power running, a current or power command is executed from the ECU 14 to the DCDC converter 72 that steps down from 52V to 12V. Then, if the second battery 23 is lower than the target SOC, the DCDC converter 72 that steps down the voltage from 52V to 12V is instructed to supply power or current of 12V auxiliary or higher. If it is more than the target SOC, it directs the DCDC converter 72 to step down from 52V to 12V with less than 12V auxiliary power or current.

Next, with reference to FIG. 8, a balancing method in the case of using a second battery 23 other than the existing 12V lead battery will be described. In FIG. 8, a balancing switch (SW) 81 and a balancing resistor 82 are attached to the lines of the second battery 23 and the inverter 12, and further, a balancing switch (SW) 83 and a balancing resistor 84 are attached between the second battery 23 and GND. Then, the balancing SW 81 and 83 are controlled to be turned on and off by the ECU 14. When the SOC of the second battery 23 is smaller than the target value, a signal for turning on the balancing SW81 is sent from the ECU 14 to raise the SOC of the second battery 23. On the other hand, when the SOC of the second battery 23 is larger than the target value, a signal for turning on the balancing SW83 is sent from the ECU 14 to lower the SOC of the second battery 23.

As described above, according to the first embodiment, an inexpensive battery can be used for the battery in the lower series of the DCDC converter of the power storage system, and a new power type battery pack is planned. It can be inexpensively adjusted to the voltage range of any electric vehicle (EV).

This makes it possible to realize a combined power storage system that can be installed in electric vehicles (EVs) of various vehicle types at low cost.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

10 ... Electric vehicle, 11 ... Motor generator, 12 ... Inverter, 13 ... Battery unit (storage battery), 14 ... ECU (upper controller), 15 ... Communication line, 21 ... Power type battery pack, 22 ... (Bidirectional) DCDC converter , 23 ... Second battery, 24 ... Capacity type battery (capacity type battery pack), 25 ... Power type battery pack + terminal, 31 ... Power type battery pack side current sensor in DCDC converter, 32 ... Power type battery pack GND terminal connection Terminal, 33 ... Second battery side current sensor in DCDC converter, 34 ... Second battery + terminal connection terminal, 35 ... DCDC converter control circuit, 41 ... Capacity type battery total OCV curve, 42 ... Power type battery pack total OCV curve, 43 ... OCV for the lower limit of SOC used by the power type battery pack, 44 ... Lower limit of using the capacity type battery SOC, 45 ... SOC range using the capacity type battery, 46 ... SOC range using the power type battery pack, 51 ... Power type battery pack Total OCV, 52 ... Capacity type battery pack usage upper limit SOC, 53 ... Power type battery pack use SOC range, 54 ... Power type battery pack lower limit after voltage return SOC, 55 ... Capacity type battery usage lower limit SOC, 61 ... Capacity type Reception step from battery, 62 ... Demand current estimation step, 63 ... Capacity type battery total OCV estimation step, 64 ... Power type battery pack total OCV estimation step, 65 ... DCDC converter output voltage determination step, 66 ... DCDC converter output Voltage command step, 71 ... 12V auxiliary equipment, 72 ... 52V to 12V (one-way) DCDC converter, 81 ... (inverter side) balancing SW, 82 ... (inverter side) balancing resistance, 83 ... (GND side) balancing SW, 84 ... (GND side) Balancing resistance.

Claims (6)

Power type battery pack and
A bidirectional step-up DCDC converter connected to a terminal opposite to the terminal of the power type battery pack connected in parallel with the capacity type battery, and
A second battery connected to a terminal on the opposite side of the terminal connected to the power type battery pack of the bidirectional step-up DCDC converter, and
Equipped with
Using the current charge rate, current, voltage of the capacity type battery, the function table of the total open circuit voltage and charge rate of the capacity type battery, and the function table of the open circuit voltage and charge rate of the power type battery pack, the current time Based on the charge rate of the capacity type battery and the current demand of the composite power storage system, the voltage on the power type battery pack side of the bidirectional boost type DCDC converter is set, and the + terminal potential of the power type battery pack is set to the capacity type battery. A composite power storage system characterized in that it is smaller than the open circuit voltage at the lower limit of the charge rate range and higher than the open circuit voltage at the upper limit of the charge rate of the capacitive battery. The combined power storage system according to claim 1.
The voltage of the + terminal of the power type battery pack is set to the open circuit voltage of the charge rate with respect to the current time of the capacity type battery, and the current battery capacity [Ah] of the power type battery pack is set to the current time of the power type battery pack. A composite power storage system characterized in that a potential obtained by multiplying a value obtained by subtracting a target charge rate from a charge rate by a constant value and a value obtained by adding a value obtained by multiplying the current flowing through the power type battery pack by a constant value. The combined power storage system according to claim 1.
A composite power storage system characterized by linearly converting the total potential of the power type battery pack at the current time. Power type battery pack and
A bidirectional step-up DCDC converter connected to a terminal opposite to the terminal of the power type battery pack connected in parallel with the capacity type battery, and
A second battery connected to a terminal on the opposite side of the terminal connected to the power type battery pack of the bidirectional step-up DCDC converter, and
Equipped with
When the battery used for backing up the auxiliary power is used for the second battery, the step-down one-way DCDC converter provided between the + terminal of the second battery and the capacity type battery is used, and the first one is used. (Ii) A means for obtaining the charge rate of the battery and a means for controlling the step-down one-way DCDC converter are provided.
When the charge rate of the second battery is lower than the target charge rate, the step-down one-way DCDC converter is set to a power or current larger than the auxiliary power or current.
A composite power storage system characterized in that when the charge rate of the second battery is higher than the target charge rate, the step-down one-way DCDC converter is controlled to a power or current smaller than the auxiliary power or current. Power type battery pack and
A bidirectional step-up DCDC converter connected to a terminal opposite to the terminal of the power type battery pack connected in parallel with the capacity type battery, and
A second battery connected to a terminal on the opposite side of the terminal connected to the power type battery pack of the bidirectional step-up DCDC converter, and
Equipped with
When a battery other than the battery used for backing up auxiliary power is used for the second battery, the first switch, the first resistor, and the second battery are located between the + terminal of the second battery and the capacity type battery. A second switch and a second resistor are provided between the ground and the ground.
If the charge rate of the second battery is lower than the target, the first switch is turned on.
A combined power storage system characterized in that the second switch is turned on when the charge rate of the second battery is higher than the target. It is a control method for a combined power storage system that connects a power-type battery pack that emphasizes power performance and a capacity-type battery that emphasizes capacity performance in parallel.
(A) A step of receiving the charge rate, the total voltage, and the current from the battery controller of the capacity type battery.
(B) Steps for estimating the demand current and
(C) A step of calculating the open circuit voltage corresponding to the current charge rate of the capacity type battery based on the open circuit voltage characteristic of the capacity type battery, and
(D) A step of calculating the total open circuit voltage of the power type battery pack corresponding to the central charge rate of the power type battery pack, and
(E) A step of calculating the output voltage of the DCDC converter based on the values of the target resistance and the target capacitance preset in the electronic control device, and
(F) A step of transmitting a command voltage to the controller of the DCDC converter based on the output voltage calculated in the step (e).
A control method for a combined power storage system, characterized in that it has.

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