Nec Energy Devices, Ltd.

Nec Corporation

Envision Aesc Japan Ltd.

Envision Aesc Energy Devices Ltd.

Aesc Japan Ltd.

Shin Suzuki

Yoichiro Tashiro

Hiroaki Ueno

Ryou Shiozaki

Yuki Hori

This power storage system is provided with a secondary cell pack and a system protection unit having a system protection function of cutting off the secondary cell pack from the outside of the power storage system. This secondary cell pack is provided with a secondary cell and a cell protection unit having a cell protection function of cutting off the secondary cell from the outside of the secondary cell pack. The cell protection unit further monitors a state value that indicates the state of the secondary cell and controls implementation of the system protection function and the cell protection function on the basis of the state value.

Power storage system and cell protection method which protects the cell by both cutting from the cell pack and the cell pack from the system

A power storage system has a plurality of secondary battery packs and a host device. The secondary battery packs each have: secondary batteries; a charge switch means that turns a charging path to the secondary batteries ON and OFF; a discharge switch means that turns a discharging path from the secondary battery ON and OFF; and a current-limiting means that causes the secondary battery to discharge while limiting the current to, or below, a fixed value. When switching from the secondary battery pack connected to the input/output terminals of the system to a first secondary battery pack in which voltage is higher than in the second secondary battery pack, the host device causes the charge switch means of the second secondary battery pack to turn OFF the charging path while in a state in which the current limiting means of the first secondary battery pack will cause a discharge operation to begin while limiting the flow of current.

Secondary battery pack connection control method for controlling connection of input and output terminals in power storage system comprising plurality of secondary battery packs

A controller () reads out a voltage value correlated with the ambient temperature of a battery () measured by a temperature measurer () from a storage device (), so that a charger () charges the battery () at the voltage value read out by the controller ().

Charging apparatus

In an electricity storage system that has a plurality of secondary battery packs, at the time of switching the object that is to be charged from a first secondary battery pack to a second secondary battery pack that has voltage across terminals lower than that of the first secondary battery pack, by causing a current-limiting circuit of the second secondary battery pack to operate, forms a path for the flow of a charging current for charging secondary batteries that are provided in the second secondary battery pack, and starts charging of the second secondary battery pack while limiting the charging current to a fixed value or less by means of the current-limiting circuit.

Electricity storage system, method for controlling secondary battery packs, and secondary battery pack

Remaining capacity calculation section () calculates remaining capacities for each of cells (-) and (-) connected in parallel with each other, and control section () discharges one of cells (-) and (-) having priority until the remaining capacity of that cell becomes equal to a second threshold value stored in storage section (), if the remaining capacity of the one of the cells calculated by remaining capacity calculation section () is equal to a first threshold value stored in storage section ().

Discharge controller

An average current value that is the average value of current values is found by connecting a detection resistor in parallel to two terminals that are the object of measurement, measuring the current value that flows in the detection resistor, and subjecting the current value to time-quadrature, and further, dividing the current value that follows integration by the integration time. The average current value is converted to a digital signal and sent to an arithmetic means (processor). The arithmetic means calculates the voltage value across the two terminals from the average current value and the resistance value of the detection resistor.

Voltage measuring circuit and method

A battery sensing section measures a voltage across a secondary battery. A current sensing section measures a current flowing through the secondary battery. A control section holds the value of an external impedance present in a discharge path outside the secondary battery, discharges the secondary battery from a first time to a second time at which an integrated discharge capacity based on a measured discharge current becomes equal to a predetermined discharge capacity reference value, calculates the internal impedance present in the secondary battery at the second time based on the measured voltage, calculates the second open voltage at the second time by multiplying the sum of the external impedance and the internal impedance by the measured discharge current, and calculates the recovered capacity of the secondary battery based on the first open voltage at the first time, the second open voltage and the discharge capacity reference value.

Degradation measurement device, secondary battery pack, degradation measurement method, and program

A power storage system includes a plurality of secondary battery packs and an upper controller. When causing an additional discharge secondary battery pack that is not being discharged to start being discharged by connecting the additional discharge secondary battery pack in parallel with a discharging secondary battery pack that is being discharged, in a state in which some of the secondary battery packs are being discharged, the upper controller predicts discharge start timing at which inter-terminal voltages of the additional discharge secondary battery pack and the discharging secondary battery pack correspond to each other. Subsequently, the upper controller causes the additional discharge secondary battery pack to start being discharged at the discharge start timing.

Power storage system and secondary battery control method

Power storage system having current limiting means to control multiple parallel connected battery packs

Remaining capacity calculation section () calculates the remaining capacity for each of cells (-) and (-) connected in parallel with each other, and control section () stops discharge of the first cell from cells (-) and (-), whose remaining capacity calculated by remaining capacity calculation section (), has become equal to a threshold value stored in storage section () after the start of discharge of cells (-) and (-).

In order to provide a battery module control system able to reuse an arbitrary secondary battery module through a simple, inexpensive system, the present invention includes: a plurality of battery modules that are connected to each other in parallel; switch circuits that are provided on charge and discharge routes of a plurality of the battery modules; an average impedance value calculation section (control section) that calculates average impedance values of a plurality of the battery modules; a maximum allowable charge-and-discharge rate input section (input section) that inputs maximum allowable charge-and-discharge rates of a plurality of the battery modules; an allowable voltage difference calculation section (control section) that calculates allowable voltage differences of a plurality of the battery modules on the basis of the average impedance values calculated by the average impedance value calculation section and the maximum allowable charge-and-discharge rates input by the maximum allowable charge-and-discharge rate input section; a common voltage detection section (control section) that detects a voltage of a common charge and discharge route of a plurality of the battery modules; and a plurality of voltage detection sections (control section) that detect voltages of a plurality of the battery modules, wherein, when a difference between the voltage detected by the common voltage detection section and the voltage detected by the voltage detection section corresponding to a predetermined battery module is greater than an allowable voltage difference of the predetermined battery module, a switch circuit provided on a charge and discharge route of the predetermined battery module is so controlled as to be turned OFF.

Battery module control system and battery module control method

A secondary battery pack of the present invention includes a secondary battery blockin which a plurality of unit blocksare connected in series; battery adjustment sectionsthat are each provided for each of the unit blocksand have a function of monitoring the voltage of secondary batteries and a function of adjusting the balance; a charge switch; and a discharge switch. The secondary battery pack includes transmission sectionsthat receive information from the corresponding battery adjustment sections. The transmission sections are connected to the preceding or subsequent transmission sections and are so set that at least either information input from the preceding transmission sections or information input from the battery adjustment sectionsis output to the subsequent transmission sections. The transmission sections are equipped with a constant current transmission section that transmits with a constant value of current; and a current detection section that can detect the value of the constant current.

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Kanagawa, Japan

Shin Suzuki