JP5842342B2 - Power system - Google Patents

Description

The present invention relates to a power supply system, in particular, it relates to a power supply system battery module are connected in parallel.

In recent years, motors have been actively used as power generation sources in order to reduce the amount of carbon dioxide (CO ₂ ), which is a kind of greenhouse gas. For example, in an automobile or the like, an internal combustion engine such as an engine is generally used as a power generation source. However, in recent years, a hybrid vehicle (HV: Hybrid Vehicle) or a power that uses an engine and a motor together as a power generation source. Research and development of electric vehicles (EVs) that use only a motor as a generation source have been actively conducted.

  In an apparatus using a motor as a power generation source, a secondary battery such as a lithium ion secondary battery capable of charging and discharging DC power is used as a power source. Generally, a secondary battery is comprised from a some battery module and the management control apparatus which integrates and manages and controls the state of these battery modules (for example, refer patent documents 1-3). Here, the battery module is a module in which a battery cell in which a plurality of single battery cells are stacked and a monitoring board for monitoring the voltage / current of the battery cell and the like are modularized. Moreover, said management control apparatus calculates | requires the battery state of the whole secondary battery by integrating the monitoring result of the monitoring board | substrate provided in each battery module, and notifies the battery state outside.

  When building a system that uses a secondary battery as a power source, the system designer must use a secondary battery, a DC / DC converter that controls charging / discharging of the secondary battery, and an inverter that drives an electric device to be controlled. Must be prepared separately and these devices must be combined to meet the system specifications. Similarly, when constructing a large-capacity system, it is necessary to separately obtain a large-capacity secondary battery (for example, several megawatts) and a large-capacity converter and combine them according to the specifications of the system.

  By the way, when constructing a system using a secondary battery as a power source, it is necessary to examine in detail the specifications of the main circuit and the specifications of the input / output signals provided in the devices to be combined. For example, it is necessary to specifically examine the signal relationship such as what signal is output from a certain device and to which device the signal is input. For this reason, there is a problem that a great deal of time and effort are required for system design.

  In addition, since the devices to be combined are individually provided with control devices, the number of control devices increases when these devices are combined. For example, when a secondary battery and a DC / DC converter are combined, a control device provided in the DC / DC converter is connected to a control device (management control device) provided in the secondary battery, and the DC / DC converter is connected. The control device provided in the control device controls the DC / DC converter while referring to the battery state required by the secondary battery management control device. Thus, there has been a problem that the cost of the entire system increases due to an increase in the number of control devices.

  A large-capacity secondary battery designed to meet the specifications of a certain large-capacity system is considered to be an optimal secondary battery for use in the system. However, it is difficult to use in other systems with different specifications, and there is a problem that versatility is low. If the versatility is low, it is necessary to design a dedicated secondary battery for each large-capacity system, which inevitably increases the cost.

Japanese Patent No. 4179383 Japanese Patent No. 3655277 JP 2009-284668 A

The present invention was made in view of the above circumstances, a high cost is versatile, and an object thereof is to provide a power supply system which can easily perform system design.

According to one aspect of the present invention, a secondary battery capable of storing electric power by charging, a charging / discharging circuit for adjusting electric power charged in the secondary battery and electric power discharged from the secondary battery, and a charging / discharging circuit Controls charging / discharging of its own battery module based on the power input / output terminal used for DC power input / output, the output voltage command value during power running and the charge power command value during charging, and between other battery modules A control circuit for transmitting and receiving the remaining battery capacity and sharing the remaining battery capacity of all battery modules, and a plurality of battery modules in which power input / output terminals are arranged in parallel connection, and an output voltage command to the control circuit and a host controller for transmitting the value and the charge electric power command value, the control circuit, the current command value by performing limiter processing on the difference between the detected voltage value of the output voltage command value and the battery module A limiter processing unit that outputs, a current command value generation unit that generates a first shared current command value shared by its own battery module with respect to the current command value, based on the remaining battery capacity of all the shared battery modules; A controller that generates a control signal that sets a current error signal that indicates a difference between the shared current command value and the detected current value of the battery module to zero, and a PWM that generates a PWM pulse signal based on the control signal and outputs the PWM pulse signal to the charge / discharge circuit The gist is to include a signal generation unit.

According to the present invention, a high cost is versatile, it is possible to provide a power supply system which can easily perform system design.

It is a circuit diagram which shows the principal part structure of the power supply system which concerns on the 1st Embodiment of this invention. It is a conceptual diagram which shows the control method at the time of pressure | voltage rise (discharge) operation | movement of the power supply system which concerns on the 1st Embodiment of this invention. It is a conceptual diagram which shows the control method at the time of pressure | voltage fall (charge) driving | operation of the power supply system which concerns on the 1st Embodiment of this invention. It is a circuit diagram which shows the principal part structure of the power supply system which concerns on the 2nd Embodiment of this invention. It is a circuit diagram which shows the principal part structure of the power supply system which concerns on the 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(First embodiment)
As shown in FIG. 1, the power supply system according to the first embodiment of the present invention includes a secondary battery 10 capable of storing electric power by charging, electric power charged in the secondary battery 10, and a secondary battery. A charging / discharging circuit 20 for adjusting electric power to be discharged, and power input / output terminals P11, P12,..., Pn1, Pn2 used for input / output of DC power of the charging / discharging circuit 20; A plurality of battery modules M1, M2,..., Mn having terminals P11, P12,..., Pn1, Pn2 arranged in parallel, and battery modules M1, M2,. And a host controller 40 that transmits an output voltage command value during power running and a charge power command value during charging to Mn, and all the battery modules M1, M2,. , M2, ... , Remaining battery capacity of the Mn (SOC: State Of Charge) and the depth of discharge (DOD: Depth Of Discharge) of share at least one.

  The secondary battery 10 is a battery capable of storing electricity by charging a lithium ion battery, a nickel metal hydride battery, or the like. The secondary battery 10 may be a stack of a plurality of single battery cells such as lithium ion secondary battery cells. The secondary battery 10 is connected to the protection circuit 11 and the balance circuit 12.

  When the overcurrent to the secondary battery 10 is detected, the protection circuit 11 cuts off the current and protects the secondary battery 10. Further, the protection circuit 11 adjusts the balance of the cell voltage by, for example, disconnecting the overcharged battery cell. When the protection circuit 11 determines that overcharge / overdischarge cannot be avoided by adjusting the cell voltage balance, the protection circuit 11 issues an alarm to the charge / discharge circuit 20 to stop charging / discharging.

  The balance circuit 12 detects the voltage and temperature of the secondary battery 10 and calculates the SOC. The balance circuit 12 transmits the calculated SOC information to the control circuit 21 of the charge / discharge circuit 20.

  The charge / discharge circuit 20 is connected to the control circuit 21. The charge / discharge circuit 20 is a circuit that performs power conversion between input power and output power based on a power control command from the control circuit 21. As the charge / discharge circuit 20, a DC / DC converter, a step-up / step-down chopper, or the like can be employed. The charging / discharging circuit 20 includes a sensor, detects current and voltage output from the charging / discharging circuit 20 by the sensor, and transmits the detected current detection value Ibat_ad and detection voltage value Vdc_lpf to the control circuit 21.

  The control circuit 21 performs switching control between a charging mode for charging the secondary battery 10 with electric power and a discharging mode for discharging electric power from the secondary battery 10 to an external device. Further, the control circuit 21 performs power control of input power to the secondary battery 10 and output power from the secondary battery 10.

The control circuit 21 transmits / receives SOC information to / from other battery modules M1, M2,..., Mn via signal input / output terminals C11, C12,. , Mn share SOC (%) with each other. Further, the control circuit 21 receives the output voltage command value Vdc_ref or the charging power command value Wc_ref from the host controller (ECU) 40 via the signal input / output terminals C11, C12,.

Based on the SOC information, the output voltage command value Vdc_ref, and the charging power command value Wc_ref, the control circuit 21 calculates a current target value Ibat_ref that should be undertaken by the battery modules M1, M2,. The control circuit 21 calculates the difference between the current target value Ibat_ref and the current detection value Ibat_ad, and calculates an appropriate control amount using a PI (proportional / integral) controller. The control circuit 21 outputs a pulse width modulation (PWM) signal corresponding to the control amount to the charge / discharge circuit 20. The control circuit 21 performs control for overvoltage protection, overcurrent protection, and overtemperature protection based on the voltage value and current value of the charge / discharge circuit 20 received from the sensor.

  The host controller (ECU) 40 and each of the battery modules M1, M2,..., Mn are connected by a serial bus such as a CAN (Controller Area Network) bus. The host controller 40 performs serial communication with the control circuit 21 provided in each of the battery modules M1, M2,... Mn via the serial bus and refers to the monitoring result. The host controller 40 receives signals including information indicating the calculation result of the control circuit 21 and information indicating the control amount (for example, charge power command value) of the charge / discharge circuit 20 as signal input / output terminals C11, C12,. ... Input / output is possible via C1n.

  The host controller 40 may be realized by hardware or may be realized by software. When realized by software, the host controller 40 is configured using a central processing unit (CPU), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and a program for realizing the functions of the host controller 40 described above. Is realized by causing the CPU to read and execute. The program for realizing the functions of the host controller 40 may be stored in the ROM, or the host controller 40 is communicated through signal input / output terminals C11, C12,..., C1n. You may make it input to.

  The power input / output terminals P11, P12,..., Pn1, Pn2 are connected to, for example, an inverter (INV) 30 that converts DC power into AC power. The inverter 30 is connected to a motor (M) 50 as a load. The motor 50 is driven by the inverter 30.

[Operation during power running]
An operation during powering operation (step-up) of the power supply system according to the first embodiment will be described with reference to FIG.

First, the control circuit 21 of each battery module M1, M2,..., Mn receives the output voltage during powering from the host controller 40 via the signal input / output terminals C11, C12,. The command value Vdc_ref is received through the communication bus. Further, the control circuit 21 receives the detected voltage value Vdc_lpf detected by the sensor of the charge / discharge circuit 20 via the signal input / output terminals C11, C12,..., C1n.

Next, the control circuit 21 calculates the difference between the output voltage command value Vdc_ref and the detected voltage value Vdc_lpf, and after performing appropriate processing by the PI controller 60, the limiter processing unit 61 does not cause the control amount to be excessive or excessive. A current command value Ibat_ref obtained by applying a limiter to is calculated.

  Next, based on the SOC shared by the current command value generation unit 62, the control circuit 21 calculates the shared power of the unit for the current command value Ibat_ref. Specifically, the shared power of the own unit is the ratio of the remaining battery level (SOC) of the own unit to the total remaining battery level (SOC) of all units. The current command value generation unit 62 generates a shared current command value Ibat_ref1 shared by the own unit. At this time, if the remaining capacity of the battery module M1 is small and the current indicated by the current command value cannot be discharged, the current command value generation unit 62 generates a current command value that limits the discharge amount (limiter). processing). Moreover, it is preferable that the electric current command value production | generation part 62 calculates the shared electric power of each unit so that the battery remaining charge of each unit may become equal.

  However, if there is a battery module M1, M2,..., Mn that has stopped abnormally due to some problem such as overvoltage, overcurrent, or communication error, the corresponding battery module has its own battery level (SOC) ) Is zero and transmitted to the communication bus. In the corresponding battery module, when the remaining battery level is zero, the shared power is also zero and the current is not discharged. In other battery modules, the shared power increases, so the shared power can be automatically optimized.

  Next, the arithmetic unit C21 (C22,..., C2n) receives the shared current command value Ibat_ref1 generated by the current command value generation unit 62. The computing unit C21 receives the current detection value Ibat_ad1 detected by the sensor of the charge / discharge circuit 20. The computing unit C21 subtracts the current detection value Ibat_ad1 from the shared current command value Ibat_ref1 that is the shared power of its own unit, thereby obtaining a current error signal indicating these differences. The current error signal is input to the PI controller 63 and the limiter processing unit 64. The PI controller 63 and the limiter processing unit 64 generate and output a control signal that makes the current error signal output from the computing unit C21 zero.

  Next, the PWM signal generation unit 65 generates a PWM pulse having an appropriate duty ratio with respect to the control amount based on the control signals from the PI controller 63 and the limiter processing unit 64. The transistor provided in the DC / DC converter performs a switching operation (PWM switching operation) by the generated PWM pulse.

[Operation during regenerative operation]
The operation during the regenerative operation (step-down) of the power supply system according to the first embodiment will be described with reference to FIG.

  Each of the battery modules M1, M2,..., Mn transmits the remaining battery level (SOC) to a communication bus (not shown) between the units, and therefore discharges from the remaining battery level (SOC). Depth (DOD) is calculated. Specifically, DOD = 100−SOC (1) can be calculated. Each unit at the time of step-down (charging) operation determines the amount of power shared based on the calculated depth of discharge (DOD).

  First, the control circuit 21 of each battery module M1, M2,..., Mn receives charging power during regeneration from the host controller 40 via signal input / output terminals C11, C12,. The command value Wc_ref is received through the communication bus.

Next, the control circuit 21 calculates the shared power of the own unit with respect to the charging power command value Wc_ref. Specifically, the shared power of the own unit is a ratio of the discharge depth (DOD) of the own unit to the sum of the discharge depths (DOD) of all units. The current command value generation unit 62 obtains the ratio of the discharge depth of its own unit to the sum of the discharge depths of all units, and obtains the shared power of the unit based on the charge power command value and the ratio . At this time, if the remaining capacity of the battery module M1 is large and the current indicated by the current command value cannot be charged, the current command value generation unit 62 generates a current command value that limits the amount of charge (limiter). processing). Moreover, it is preferable that the electric current command value generation part 62 calculates so that the battery remaining amount of each unit may become equal.

  However, if there is a battery module M1, M2,..., Mn that has stopped abnormally due to some problem such as overvoltage, overcurrent, or communication error, the corresponding battery module has its own battery level (SOC) ) Is zero, it is transmitted to the communication bus. In other battery modules, when the remaining battery level (SOC) is zero, the DOD is also assumed to be zero. In the corresponding battery module, when the depth of discharge is zero, the shared power is also zero and the current is not charged. In other battery modules, the shared power increases, so the shared power can be automatically optimized.

  Next, the division unit 66 divides the value generated by the current command value generation unit 62 by the battery voltage detection value Vbat detected by the sensor of the charge / discharge circuit 20, and outputs a shared current command value Ibat_ref1.

  Next, the arithmetic unit C21 (C22,..., C2n) receives the shared current command value Ibat_ref1 generated by the division unit 66. The computing unit C21 receives the current detection value Ibat_ad1 detected by the sensor of the charge / discharge circuit 20. The computing unit C21 subtracts the current detection value Ibat_ad1 from the shared current command value Ibat_ref1 that is the shared power of its own unit, thereby obtaining a current error signal indicating these differences. The current error signal is input to the PI controller 63 and the limiter processing unit 64. The PI controller 63 and the limiter processing unit 64 generate and output a control signal that makes the current error signal output from the computing unit C21 zero.

  Next, the PWM signal generation unit 65 generates a PWM pulse having an appropriate duty ratio with respect to the control amount based on the control signals from the PI controller 63 and the limiter processing unit 64. The transistor provided in the DC / DC converter performs a switching operation (PWM switching operation) by the generated PWM pulse.

  According to the power supply system according to the first embodiment, each of the battery modules M1, M2,..., Mn is connected in parallel as equal, and the battery modules M1, M2,. .., Mn shares the SOC of all battery modules, so that each can determine and operate its own shared power.

  Furthermore, according to the power supply system which concerns on 1st Embodiment, since each of each battery module M1, M2, ..., Mn is equivalent, it can respond by one system, design, Production can be completed in one process, and cost, reliability, and development time can be greatly improved.

  Furthermore, according to the power supply system according to the first embodiment, each of the battery modules M1, M2,..., Mn is unitized, and a plurality of them are connected in series or in parallel as necessary. Since it can be connected, versatility can be improved and cost reduction can be achieved.

  Furthermore, according to the power supply system according to the first embodiment, since the control system of each battery module M1, M2,..., Mn is completed in each module, some problem has occurred. However, the operation can be continued without adversely affecting other modules.

(Second Embodiment)
As shown in FIG. 4, the power supply system according to the second embodiment of the present invention is different from the power supply system shown in FIG. 1 in that an addition operation device 70 is further provided. Others are substantially the same, and thus redundant description is omitted.

  The addition arithmetic unit 70 receives the remaining battery capacity (SOC) of all the battery modules M1, M2,..., Mn, the total remaining battery capacity (ΣSOC), which is the sum of the SOCs, and the depth of discharge (DOD). ) At least one of the total discharge depths (ΣDOD). The addition arithmetic unit 70 transmits ΣSOC and ΣDOD to the communication bus.

  Each of the battery modules M1, M2,..., Mn receives ΣSOC and ΣDOD from the communication bus, and calculates each shared power.

  The power supply system according to the second embodiment can obtain the same effects as those of the power supply system according to the first embodiment.

  Furthermore, according to the power supply system according to the second embodiment, by providing the addition calculation device 70, information transmission between the battery modules M1, M2,. A highly oriented system configuration can be obtained.

  Furthermore, according to the power supply system according to the second embodiment, even if the number of battery modules M1, M2,..., Mn connected in parallel increases, the number of channels for SOC communication increases. Can be prevented.

(Third embodiment)
As shown in FIG. 5, the power supply system according to the third embodiment of the present invention is different from the power supply system shown in FIG. 1 in that a voltage sensor 80 is further provided. Others are substantially the same, and thus redundant description is omitted.

  The voltage sensor 80 is a sensor that measures the output voltage of the battery modules M1, M2,. The voltage sensor 80 is provided outside all the battery modules M1, M2,. The voltage sensor 80 transmits a value obtained by filtering noise from the reading value of the sensor provided in the charge / discharge circuit 20 to the communication bus.

  Even in the power supply system according to the third embodiment, the same effect as that of the power supply system according to the first embodiment can be obtained.

  Furthermore, according to the power supply system according to the third embodiment, the voltage sensor 80 is provided outside the battery modules M1, M2,. It can be set as the system which transmits the value which filtered the noise from the value to a communication bus. That is, by providing the voltage sensor 80 common to each module, it is possible to control the bias of the shared power among the modules without depending on the variation of the sensors provided in the charge / discharge circuit 20 and configure a highly stable system. be able to.

  Furthermore, according to the power supply system according to the third embodiment, the provision of the voltage sensor 80 common to the modules leads to a reduction in the number of components and enables a reduction in price.

(Other embodiments)
As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques should be apparent to those skilled in the art.

  For example, in the embodiment, only the main configuration of the power supply system is described, but it goes without saying that other configurations are naturally included.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

C11, C12,... Signal input / output terminal C21: arithmetic unit M1, M2, Mn ... battery module P11, P12, ... power input / output terminal 10 ... secondary battery 11 ... protection circuit 12 ... balance circuit 20 ... charge / discharge circuit 21 ... Control circuit 30 ... Inverter 40 ... Higher controller 50 ... Motor 60 ... PI controller 61 ... Limiter processing unit 62 ... Current command value generation unit 63 ... PI controller 64 ... Limiter processing unit 65 ... PWM signal generation unit 66 ... Dividing unit 70 ... Addition Arithmetic unit 80 ... Voltage sensor

Claims (4)

A secondary battery capable of storing electric power by charging, a charge / discharge circuit for adjusting power charged in the secondary battery and power discharged from the secondary battery, and input / output of DC power of the charge / discharge circuit Controls charging / discharging of its own battery module based on the power input / output terminal to be used, the output voltage command value during power running and the charge power command value during charging, and transmits / receives remaining battery capacity to / from other battery modules A control circuit that shares the remaining battery capacity of all the battery modules, and a plurality of battery modules in which the power input / output terminals are arranged in parallel,
A host controller that transmits the output voltage command value and the charging power command value to the control circuit;
The control circuit calculates a current command value by performing a limiter process on the difference between the output voltage command value and the detected voltage value of the battery module; and
Based on the battery remaining capacity of all the battery modules shared, a current command value generating unit that generates a first shared current command value shared by the battery module for the current command value;
A controller that generates a control signal that sets a current error signal indicating a difference between the first shared current command value and the detected current value of the battery module to zero;
A PWM signal generator that generates a PWM pulse signal based on the control signal and outputs the PWM pulse signal to the charge / discharge circuit;
A power supply system comprising: The current command value generation unit calculates the discharge depth of all the battery modules based on the remaining battery capacity of all the battery modules shared, and calculates the discharge depth of all the battery modules based on the calculated discharge depth. Obtain the ratio of the depth of discharge of the own battery module with respect to the sum, determine the shared power of the own battery module based on the charge power command value and the ratio,
And a divider for obtaining a third shared current command value by dividing the shared power by the detected voltage value of the battery module,
The power supply system according to claim 1, wherein the controller generates a control signal that sets a current error signal indicating a difference between the third shared current command value and a detected current value of the battery module to zero.   An addition calculation device that receives the battery remaining capacity of all the battery modules and calculates at least one of a total battery remaining capacity that is a sum of the battery remaining capacity and a total discharge depth that is a sum of the discharge depths; The power supply system according to claim 1 or 2, further comprising:   The power supply system according to any one of claims 1 to 3, further comprising a voltage sensor that measures output voltages of all the battery modules outside the battery modules.

Images