JP2019049416A - Hybrid construction machine - Google Patents

Abstract

To provide a hybrid construction machine capable of detecting an increase in the reversible resistance of a part of battery cells included in an assembled battery configuration in which a plurality of battery cells are connected in multiple series.SOLUTION: From the total voltage of a plurality of battery cells connected in multiple series and the voltage of each battery cell, extracted are a highest total voltage extracted value which is the highest value and a lowest total voltage extracted value which is the lowest value of the total voltage of the plurality of battery cells within a predetermined period, and a highest cell voltage extracted value which is the highest value and a lowest cell voltage extracted value which is the lowest value in the first predetermined period of the cell voltages of the plurality of battery cells. If a determination reference value calculated based on the extracted values becomes equal to or greater than a predetermined threshold value, it is determined that an internal resistance abnormality has occurred in at least one of the plurality of battery cells.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a hybrid construction machine.

  In recent years, not only in the field of automobiles but also in the field of industrial mobile bodies such as construction machinery, it has become more important to respond to stricter environmental regulations and develop energy saving technologies each year. From such a background, the hybrid technology of the power source, which has been developed centering on the automobile field, is also developed in the construction machine field.

  In general, construction machines such as hydraulic shovels driven by a hydraulic system are configured with a hydraulic pump driven by an engine according to the work of maximum load, so that all work from light load work to heavy load work can be handled. The hydraulic work device is driven by the pressure oil discharged from the hydraulic pump. In addition, heavy load work is heavy digging work etc. which perform excavation and loading of earth and sand frequently with a hydraulic work device. In addition, light load work refers to work such as horizontal pulling to smooth the ground.

  However, heavy load work in a construction machine is a part of the entire work, and at light load work, the engine capacity is left. This is one of the factors that make it difficult to reduce the fuel consumption of the hydraulic shovel (hereinafter sometimes referred to as fuel consumption). As a technique in view of this point, there is known a hybrid type construction machine that assists (assists) a part of engine output with an output from a power storage device and a motor in order to reduce fuel consumption.

  For example, a secondary battery such as a lithium ion battery or a nickel hydrogen battery, a capacitor (such as an electric double layer capacitor), or the like is used as a power storage device mounted on a hybrid construction machine. In particular, mounting a secondary battery having a larger storage capacity than a capacitor is expected to have a greater effect of reducing fuel consumption as a hybrid construction machine, and in recent years a construction machine having a secondary battery having a large storage capacity has been developed. ing.

  By the way, in the secondary battery, it is generally known that the internal resistance (hereinafter, may be abbreviated as resistance) is increased as aging deterioration due to charging and discharging of current and storage. Such an increase in resistance is usually an irreversible increase in resistance (hereinafter referred to as an irreversible increase in resistance). On the other hand, in some secondary batteries, if charging and discharging of a large current is continuously carried out with respect to the capacity of the battery, a reversible increase in resistance (hereinafter referred to as "reversibility") different from the normal irreversible resistance increase. It is reported that if charging / discharging is performed in a state where the increase in the reversible resistance is occurring, deterioration of the secondary battery is promoted.

  With secondary batteries for hybrid construction machines, charging and discharging of large current is more likely to be continued as compared with secondary batteries for hybrid vehicles, etc., and it is expected that use in situations where reversible resistance increase is likely to occur . Therefore, for example, Patent Document 1 discloses a technique for detecting an increase in the reversible resistance of the secondary battery and performing control to suppress the promotion of the deterioration. Specifically, in Patent Document 1, in a secondary battery system including a battery controller that controls charging and discharging of the secondary battery and an overall controller that controls the entire system, the charging current and the discharging current of the secondary battery are It has an ammeter to detect and a voltmeter to detect the voltage of the secondary battery, and the internal resistance of the secondary battery at the time of charge and the time of discharge based on the current value and the voltage value detected by the ammeter and the voltmeter It is described that the internal resistance of the secondary battery is determined, and based on the relationship between the two, it is determined that a temporary increase in internal resistance of the secondary battery associated with charging and discharging at a large current.

Patent No. 4923116

  However, in the above-mentioned prior art, it is difficult to apply to a storage system of an assembled battery configuration in which a plurality of battery cells are connected in series. That is, in the above-mentioned prior art, when the storage system of the assembled battery configuration is viewed as one storage battery, it is possible to detect when the reversible resistance rise occurs uniformly in a plurality of battery cells constituting the storage battery. However, it is not considered to detect the increase in reversible resistance that occurs in some battery cells of the battery assembly configuration. Therefore, if the battery is continuously charged and discharged in a state where the increase in reversible resistance is generated without detecting the occurrence of the increase in reversible resistance in some of the battery cells of the assembled battery configuration, the battery cell is degraded. There is concern that it will be promoted.

  The present invention has been made in view of the above, and is directed to a hybrid construction machine capable of detecting an increase in the reversible resistance of some battery cells included in an assembled battery configuration in which a plurality of battery cells are connected in multiple series. Intended to be provided.

  The present application includes a plurality of means for solving the above problems, and an example thereof is an engine, a motor generator which assists the power of the engine at the time of power running, and generates power at the time of regeneration, A hybrid-type construction machine comprising: a hydraulic pump; a power storage device; an inverter for controlling transfer of power between the motor generator and the power storage device; and a hybrid controller for controlling the operation of the inverter The battery pack includes: a battery assembly including a plurality of battery cells connected in series; and a battery controller monitoring a total voltage of the plurality of battery cells of the battery assembly and a voltage of each battery cell, the hybrid controller From the monitoring result of the battery controller, the total voltage of the plurality of battery cells within a first predetermined period The highest total voltage extraction value that is high and the lowest total voltage extraction value that is lowest, and the highest cell voltage extraction value and lowest value that is the highest value within the first predetermined period of the cell voltages of the plurality of battery cells Voltage information extraction unit for extracting the lowest cell voltage extraction value, the highest total voltage extraction value extracted by the voltage information extraction unit, the lowest total voltage extraction value, the highest cell voltage extraction value, and the lowest cell voltage extraction value A determination reference value calculation unit that calculates at least one determination reference value for determining internal resistance abnormalities of the plurality of battery cells of the power storage device based on the at least one calculated by the determination reference value calculation unit; An abnormality determination unit that determines that an internal resistance abnormality has occurred in at least one of the plurality of battery cells of the assembled battery when the determination reference value is equal to or greater than a predetermined threshold value.

  According to the present invention, it is possible to detect an increase in the reversible resistance of some battery cells included in a battery assembly configuration in which a plurality of battery cells are connected in series.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows typically the external appearance of the hybrid shovel which is an example of the hybrid type construction machine which concerns on 1st Embodiment. It is a figure which extracts and shows a hydraulic circuit system of a hybrid type with related composition. It is a figure which shows the structure of an electrical storage apparatus typically. It is a functional block diagram showing the details of a hybrid controller with related composition. It is a functional block diagram which shows the detail of a voltage information extraction part with a related structure. It is a figure which shows typically an example of the time change in the predetermined period (1st period) of the highest cell voltage in the several battery cell which comprises an assembled battery, the lowest cell voltage, and total voltage. It is a flowchart showing on behalf of the processing function of the highest cell voltage extraction part among the processing functions of a voltage information extraction part. It is a figure which shows an example of the change of the system state determined by the system state determination part. It is a flowchart which shows the processing function of an abnormality determination part. It is a figure which shows typically an example of the change for every date of a determination reference value. It is a functional block diagram showing the details of the hybrid controller in a 2nd embodiment with related composition. It is a flowchart which shows the processing function of the abnormality determination part in 2nd Embodiment. It is a figure which shows typically an example of the change for every date of the judgment reference value change amount.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a hybrid-type hydraulic shovel (hereinafter referred to as a hybrid shovel) is illustrated and described as an example of a hybrid-type construction machine, but, for example, a power storage device such as a hybrid wheel loader or a hybrid dump is mounted. The present invention can also be applied to a hybrid-type (including plug-in hybrid-type) construction machine or a battery-type construction machine that is not equipped with an engine and is driven only by the output of the storage device.

First Embodiment
A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a side view schematically showing the appearance of a hybrid shovel that is an example of a hybrid type construction machine according to the present embodiment.

  In FIG. 1, a hybrid shovel 100 includes an articulated front working machine 4 configured by connecting a plurality of front members (a boom 4A, an arm 4B, and a bucket 4C) which respectively rotate in the vertical direction, and a vehicle body The upper revolving unit 3 and the lower traveling unit 2 are provided, and the upper revolving unit 3 is provided so as to be rotatable relative to the lower traveling unit 2. The upper swing body 3 is configured by arranging respective members on a swing frame 3 a which is a base portion, and the swing frame 3 a constituting the upper swing body 3 can swing with respect to the lower traveling body 2. Further, the base end of the boom 4A of the front working machine 4 is vertically rotatably supported on one side (for example, the front and the right side) of the front of the upper swing body 3 and one end of the arm 4B is the boom It is rotatably supported in the vertical direction at an end (distal end) different from the base end of 4A, and the bucket 4C is rotatably supported at the other end of the arm 4B in the vertical direction.

  The lower traveling body 2 is a traveling hydraulic motor 2A1 (2A2) (not shown) for driving the pair of crawlers 2C1 (2C2) and crawlers 2C1 (2C2) respectively wound around a pair of left and right crawler frames 2B1 (2B2) And a speed reduction mechanism). In addition, about each structure of the lower traveling body 2, only one of the left and right pair of structures is illustrated and a code | symbol is attached | subjected, about the other structure, only the code in parentheses is shown in a figure and illustration is abbreviate | omitted. .

  The boom 4A, the arm 4B, the bucket 4C, and the lower traveling body 2 are respectively driven by a boom cylinder 4a, an arm cylinder 4b, a bucket cylinder 4c, and left and right traveling hydraulic motors 2A1 (2A2) which are hydraulic actuators. The upper swing body 3 is similarly driven via the reduction mechanism 24 by the swing hydraulic motor 3A1 which is a hydraulic actuator mounted on the swing device 3A, and performs a swing operation on the lower traveling body 2.

  An operator rides on one side (e.g., the front and the left side) on the swing frame 3a constituting the upper swing body 3 and operates the hybrid shovel 100 by the operation lever device 5A or the like described later. The cabin 5 is disposed, and a counterweight 6 for maintaining the weight balance of the vehicle body is disposed at the rear on the turning frame 3a. Also, between the cabin 5 and the counterweight 6 on the turning frame 3a, the boom cylinder 4a, the arm cylinder 4b, the bucket cylinder 4c, the turning hydraulic motor 3A1 and the left and right traveling hydraulic motor 2A1 as well as the engine 11 as a prime mover. A prime mover chamber 7 in which a control valve 18 for driving each hydraulic actuator such as (2A2) is accommodated is disposed.

  FIG. 2 is a diagram extracting and showing the hybrid hydraulic circuit system according to the present embodiment together with the related configuration.

  In FIG. 2, the hybrid hydraulic circuit system 30 assists the power of the engine 11 during power running, and generates a motor generator 14 (M / G: Motor / Generator) that generates power during regeneration, the engine 11 and motor power generation. A variable displacement hydraulic pump 17 driven by the machine 14 (when power is running), a storage device 16, an inverter 15 for controlling transfer of electric power between the motor generator 14 and the storage device 16, a cabin 5 The control system 50 includes an operation system 50 related to the operation of the hybrid shovel 100 by a mounted operator, and a hybrid controller 20 (HCU: Hybrid Control Unit) as a control device for controlling the entire operation of the hybrid hydraulic circuit system 30 including the inverter 15. .

  The hybrid hydraulic circuit system 30 also includes an engine controller 12 (ECU: Engine Control Unit) for controlling the operation of the engine 11, an accessory load 13 by an accessory such as an air conditioner driven by the engine 11, and a hydraulic pump 17. And control valve 18 for controlling the flow rate and direction of the pressure oil supplied to each hydraulic actuator (running hydraulic motor 2A1 (2A2), swing hydraulic motor 3A1, boom cylinder 4a, arm cylinder 4b, and bucket cylinder 4c) Is equipped. The engine controller 12 and the control valve 18 are controlled by a control signal from the hybrid controller 20.

  Although not shown, the hybrid hydraulic circuit system 30 has a fuel tank for storing fuel, a governor for adjusting the fuel injection amount, a turbocharger-type supercharger, and the like as related configurations of the engine 11. The related configuration of the hydraulic pump 17 includes a pilot pump or the like which is driven by the engine 11 to generate a pilot pressure.

  The operation system 50 is disposed in the cabin 5, and the operation lever device 5A for instructing the respective hydraulic actuators 2A1 (2A2), 3A1, 4a, 4b, 4c to perform desired operations by being held and operated by the operator , A gate lock lever device 5B for restricting the operation by the operation lever device 5A, a monitor 5C as a display device for the operator to confirm the vehicle body state, and an operator for starting and stopping the entire vehicle system including the engine 11 And a start switch 5D. That is, the hydraulic actuators 2A1 (2A2), 3A1, 4a, 4b and 4c which are a plurality of hydraulic loads are operated by the operation lever device 5A.

  When the gate lock lever device 5B is ON (that is, when the gate lock lever device 5B is switched to a position for restricting the operation of each hydraulic actuator by the operation lever device 5A), the vehicle travels even if the operation lever device 5A is operated The respective hydraulic actuators such as the hydraulic motor 2A for turning, the hydraulic motor 3A for turning, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4c do not operate. Therefore, in order for the operator to operate each hydraulic actuator of hybrid shovel 100, gate lock lever device 5B is turned OFF (that is, operation of each hydraulic actuator by control lever device 5A is not restricted. It is necessary to operate the control lever device 5A in this state.

  The hydraulic pump 17 has, for example, a swash plate (not shown) as a variable displacement mechanism, and controls the discharge flow rate of the hydraulic pump by adjusting the tilt angle of the swash plate. Further, although not shown, the discharge pressure sensor for measuring the pressure of the discharged pressure oil, the discharge flow rate sensor for measuring the flow amount of the discharged pressure oil, and the inclination of the swash plate of the hydraulic pump 17. A tilt angle sensor or the like that measures the angle is provided. In the present embodiment, a swash plate type variable displacement hydraulic pump is described as an example of the hydraulic pump 17. However, any hydraulic pump having a function of controlling the flow rate of the pressure oil to be discharged may be used. Alternatively, an oblique shaft pump may be used.

  The motor generator 14 has its drive shaft connected in series with the drive shaft of the hydraulic pump 17 and the drive shaft of the engine 11, and torques are mutually exchanged between the engine 11 and the hydraulic pump 17 via the drive shaft. By transmitting the power, power assist of the engine 11 and driving of the hydraulic pump 17 are performed at the time of power running, and power generation is performed at the time of regeneration.

  The inverter 15 is connected between the motor generator 14 and the storage device 16, and controls transfer of power between the motor generator 14 and the storage device 16 based on a control signal from the hybrid controller 20. Further, the inverter 15 is a power conversion device, converts DC power output from the storage device 16 into AC power at the time of power running of the motor generator 14 and supplies the AC power to the motor generator 14. The AC power generated by the generator 14 is converted to DC power and supplied to the storage device 16.

  FIG. 3 is a diagram schematically showing a configuration of the power storage device.

  In FIG. 3, power storage device 16 includes a battery assembly 16A including a plurality of (for example, 96) battery cells C1 to C96 connected in series, and a current supplied and received between battery assembly 16A and inverter 15. And a battery controller 16C (BCU: Battery Control Unit) for monitoring and controlling the battery cells C1 to C96 of the battery assembly 16A. In addition, in FIG. 3, as for a plurality of members of the same type like the plurality of battery cells C1 to C96, only a part of them is illustrated for simplicity of illustration.

  The battery assembly 16A is configured by connecting a plurality of battery cells C1 to C96 in series in order to obtain a voltage necessary to drive the inverter 15. Further, the assembled battery 16A is configured by connecting in series a plurality of (for example, eight) battery modules M1 to M8, each of which consists of a plurality of (for example, 12) battery cells connected in series. . Each of the battery modules M1 to M8 is provided with cell controllers CC1 to CC8 for measuring and adjusting the voltage of the battery cells constituting the battery modules M1 to M8, measuring the temperature, and the like. Further, the battery assembly 16A is provided with a voltage sensor 16D that detects the total voltage of the plurality of battery cells C1 to C96.

  The battery controller 16C AD-converts the measured value of the current sensor 16B and acquires it as digital current value information, and AD-converts the measured value of the voltage sensor 16D to obtain the total voltage of the plurality of battery cells C1 to C96. Acquired as digital voltage value information. The battery controller 16C monitors and controls the voltages and temperatures of the plurality of battery cells C1 to C96 via the cell controllers CC1 to CC8, and transmits control signals to the cell controllers CC1 to CC8. The voltage of the battery cells C1 to C96 is adjusted, and the voltage (also referred to as cell voltage) of each of the battery cells C1 to C96 of the plurality of battery cells C1 to C96 configuring the assembled battery 16A, the battery temperature and the like are acquired. Then, the battery controller 16C monitors the acquired information (for example, representative cell voltages (maximum cell voltage and minimum cell voltage at each measurement time point, total voltage, temperature, current) among voltages of each cell battery, etc.) To the hybrid controller 20 as The acquisition timing (sampling time) of various information by the battery controller 16C and the transmission timing to the hybrid controller 20 may be sufficiently early for the change of the acquired information, for example, the system clock of the hybrid hydraulic circuit system 30 etc. It is conceivable to obtain according to. In FIG. 3, control signals from the battery controller 16C are transmitted in series from the cell controller CC1 connected in series to the cell controller CC8, and various information from each cell controller CC1 to CC8 are serially connected in the subsequent cell controller. The case where it is finally transmitted from the cell controller CC8 to the battery controller 16C is shown.

  Battery cells C1 to C96 constituting the assembled battery 16A are, for example, lithium ion batteries. For example, when a lithium ion battery is used as a battery cell, assuming that the voltage of each battery cell is about 3.6 V, an assembled battery constituted by connecting 100 battery cells in multiple series is about 360 V Can output a DC voltage of Note that a battery pack configured by connecting 96 battery cells in multiple series outputs a DC voltage of about 345.6 V.

  The direct current power (energy) stored in the battery assembly 16A is converted from direct current to alternating current by the inverter 15 and supplied to the motor generator 14. Thereby, power storage device 16 is discharged. Further, alternating current power (energy) generated by the motor generator 14 is converted from alternating current to direct current by the inverter 15 and supplied to the storage device 16. Thus, power storage device 16 is charged.

  FIG. 4 is a functional block diagram showing the details of the hybrid controller together with the related configuration. Moreover, FIG. 5 is a functional block diagram which shows the detail of a voltage information extraction part with a related structure.

  In FIG. 4, the hybrid controller 20 extracts a plurality of voltage information extracted by the voltage information extraction unit 210 which extracts voltage values respectively acquired under a plurality of predetermined conditions from the monitoring result of the battery controller 16C. A determination reference value calculation unit 220 that calculates at least one determination reference value (described later) for determining internal resistance abnormality (reversible resistance increase) of the plurality of battery cells C1 to C96 of the assembled battery 16A based on the voltage value of And an abnormality determination unit 230 that determines an internal resistance abnormality that has occurred in at least one of the plurality of battery cells C1 to C96 of the assembled battery 16A based on the determination reference value calculated by the determination reference value calculation unit 220; All of the hybrid shovels 100 including the hybrid hydraulic circuit system 30 based on the state of the start switch 5D arranged in 5 And an output command unit 270 that adjusts the output of the ECU 12 or the inverter 15 based on the determination result of the abnormality determination unit 230. . The hybrid controller 20 also has other control functions related to the operation of the hybrid shovel 100, such as the output upper limit value calculation function of the engine 11 based on the information of the engine controller 12, and the required power calculation function of the hydraulic pump 17. However, illustration and detail are omitted for the sake of simplicity of the description.

  The system state determination unit 240 determines the system state of the hybrid shovel 100 including the hybrid hydraulic circuit system 30 from the ON / OFF state of the start switch 5D, and the system is operating (system operating state) or not It is transmitted to the voltage information extraction unit 210 as a determination result whether it is in the active state (system stop state).

  As shown in FIG. 5, the voltage information extraction unit 210 extracts the highest total voltage which is the highest value of the total voltages VT of the plurality of battery cells C1 to C96 within a first predetermined period from the monitoring result of the battery controller 16C. Highest total voltage extraction unit 213 for extracting value VTH, and lowest value for extracting lowest total voltage extraction value VTL which is the lowest value within a predetermined period (first period) of total voltages VT of battery cells C1 to C96 At the highest value within a predetermined period (first period) of the highest cell voltage Vmax which is the voltage of the battery cell showing the voltage of the highest value at a certain time point among total voltage extraction unit 214 and a plurality of battery cells C1 to C96 The highest cell voltage extraction unit 211 that extracts a certain highest cell voltage extraction value VCH, and the voltage of the battery cell that indicates the voltage of the lowest value at a certain time point among the plurality of battery cells C1 to C96 And a minimum cell voltage extracting unit 212 for extracting a minimum cell voltage extracted value VCL is the lowest value at a predetermined period of minimum cell voltage Vmin (first period) in. The highest cell voltage extraction unit 211, the lowest cell voltage extraction unit 212, the highest total voltage extraction unit 213, and the lowest total voltage extraction unit 214 each have a maximum at the end of a predetermined period (first period) (described later). There is a storage unit (not shown) for temporarily storing the cell voltage extraction value VCH, the lowest cell voltage extraction value VCL, the lowest total voltage extraction value VTL, and candidate values for outputting as the highest total voltage extraction value VTH. doing.

  FIG. 6 is a diagram schematically showing an example of the time change of the highest cell voltage, the lowest cell voltage, and the total voltage in a predetermined period (first period) in a plurality of battery cells constituting the assembled battery, The ordinate represents the highest cell voltage, the lowest cell voltage, and the total voltage, and the abscissa represents time.

  The highest cell voltage Vmax is the voltage of the battery cell showing the highest voltage at a certain time point among the plurality of battery cells C1 to C96. Therefore, a battery cell other than the battery cell showing the highest voltage at a certain sampling may show the highest voltage at the next sampling, and the battery cell showing the highest cell voltage Vmax is different every sampling Is also possible. The same is true for the lowest cell voltage Vmin, and the battery cells exhibiting the lowest cell voltage Vmin may differ from one sampling to another.

  The highest cell voltage extraction value VCH and the lowest cell voltage extraction value VCL are voltages of the highest value and the lowest value of the highest cell voltage Vmax and the lowest cell voltage Vmin in a predetermined period (first period). For example, in FIG. 6, the lowest cell voltage Vmin indicates the lowest value at time t1 in a predetermined period (first period), and the voltage at this time is at least at the end of the predetermined period (first period). It is extracted as a cell voltage extraction value VCL. Further, the highest cell voltage Vmax shows the highest value at time t2 in a predetermined period (first period), and the highest cell voltage extraction value VCH at the end of the predetermined period (first period) at this time Extracted as

  The highest total voltage extraction value VTH and the lowest total voltage extraction value VTL are voltages of the highest value and the lowest value of the total voltage VT in a predetermined period (first period). For example, in FIG. 6, the total voltage VT indicates the lowest value at time t1 in a predetermined period (first period), and the minimum voltage at this time is at the end of the predetermined period (first period). It is extracted as a voltage extraction value VTL. Also, the total voltage VT shows the highest value at time t2 in a predetermined period (first period), and the voltage at this time is taken as the highest total voltage extraction value VTH at the end of the predetermined period (first period) It is extracted.

  Since power storage device 16 is configured by connecting a plurality of battery cells C1 to C96 in series, the current to be charged and discharged can be considered to be the same for all battery cells C1 to C96. Therefore, it can be considered that the timing at which the lowest cell voltage extraction value VCL is extracted and the timing at which the lowest total voltage extraction value VTL is extracted are almost simultaneous (time t1 in FIG. 6). Similarly, it can be considered that the extraction timings of the highest cell voltage extraction value VCH and the highest total voltage extraction value VTH are almost simultaneous (time t2 in FIG. 6).

  FIG. 7 is a flowchart representing the processing function of the highest cell voltage extraction unit among the processing functions of the voltage information extraction unit.

  In FIG. 7, the highest cell voltage extraction unit 211 of the voltage information extraction unit 210 switches the system state determined by the system state determination unit 240 from the OFF state (system halted state) to the ON state (system operating state), When the system of the hybrid shovel 100 is started, it is determined whether it is the first start in one working day of the hybrid shovel 100 (step S211), and when the determination result is YES, it is stored in the storage unit Reset information (that is, storage unit storage value Vz = 0) (step S212).

  If the determination result in step S211 is NO, or if the process of step S212 is completed, subsequently, among the plurality of battery cells C1 to C96, the voltage of the battery cell showing the voltage of the highest value at that time A value (that is, the highest cell voltage Vmax) is acquired (step S213), and it is determined whether the highest cell voltage Vmax acquired in step S213 is equal to or higher than the information stored in the storage unit (storage unit storage value Vz) Step S214). If the determination result in step S214 is YES, the highest cell voltage Vmax acquired in step S213 is overwritten on the information (storage unit storage value Vz) stored in the storage unit (step S215).

  If the determination result in step S214 is NO, or if the process of step S215 ends, subsequently, whether the system state determined by the system state determination unit 240 is in the OFF state (system stop state) Is determined (step S216), and if the determination result is NO, that is, if the system is in operation, the process of steps S213 to S215 is performed until the determination result is YES, that is, until the system is stopped. repeat.

  If the determination result in step S216 is YES, the storage unit storage value (Vz) is output to the determination reference value calculation unit 220 as the highest cell voltage extraction value VCH (step S217), and the process is ended.

  The same processing is performed for the lowest cell voltage extraction unit 212, the highest total voltage extraction unit 213, and the lowest total voltage extraction unit 214 other than the highest cell voltage extraction unit 211 that constitute the voltage information extraction unit 210. For example, in the process of the highest total voltage extraction unit 213, the highest cell voltage Vmax is replaced with the total voltage VT in the flowchart of FIG. 7, and a process using a storage unit storage value different from the highest cell voltage extraction unit 211 is performed. Further, in the processing of the lowest cell voltage extraction unit 212 and the lowest total voltage extraction unit 214, the highest cell voltage Vmax is replaced with the lowest cell voltage Vmin and the total voltage VT in the flowchart of FIG. The stored value is used, and processing is performed with the inequality in step S 214 as the reverse processing, that is, Vmin ≦ Vz and VT ≦ Vz.

  FIG. 8 is a diagram showing an example of the change of the system state determined by the system state determination unit.

  In FIG. 8, on the first day, the system state switches from the system stop state to the system operation state (start), and then switches from the system operation state to the system stop state (stop), that is, system start. It shows the case where the stop is repeated twice. Similarly, on the second day, the system is started, and once stopped on the third day, the case where the start and stop are further performed is shown.

  In the highest cell voltage extraction unit 211, the lowest cell voltage extraction unit 212, the highest total voltage extraction unit 213, and the lowest total voltage extraction unit 214, a predetermined period (first period) corresponds to one working day of the hybrid shovel 100. It is defined as from the time of first system operation in to the time of each system shutdown. That is, in the case where operation and stop are repeated multiple times during one operation day, the first period is from the first system operation to each system stop. However, if there is no first system operation and no last system shutdown during one operation day, the first period is from the first system operation to the first system shutdown.

  The highest cell voltage extraction unit 211, the lowest cell voltage extraction unit 212, the highest total voltage extraction unit 213, and the lowest total voltage extraction unit 214 start at a start of a predetermined period (first period), that is, time R1 in FIG. , R2 and R3 reset the storage value stored in the storage unit (see step S212 in FIG. 7), and output extraction values at time S1, S2, S3 and S4 (see step S217 in FIG. 7). The highest cell voltage extraction unit 211, the lowest cell voltage extraction unit 212, the highest total voltage extraction unit 213, and the lowest total voltage extraction unit 214 can easily acquire date and time information from the system time and the like possessed by the hybrid controller 20. . In addition, the time when the processing date is switched may not be midnight, for example, if it is a fixed time every day, such as 22:00 and 22:00.

The determination reference value calculation unit 220 is a highest cell voltage extraction value VCH output from the highest cell voltage extraction unit 211, the lowest cell voltage extraction unit 212, the highest total voltage extraction unit 213, and the lowest total voltage extraction unit 214, and the lowest cell Each time the voltage extraction value VCL, the lowest total voltage extraction value VTL, and the highest total voltage extraction value VTH are received, the judgment reference value A and the judgment reference value B are calculated based on (Expression 1) and (Expression 2) below. Calculate
A = VCH- (VTH / N) (Equation 1)
B = (VTL / N) -VCL (Equation 2)

  Here, N is the number of battery cells C1 to C96 constituting the battery pack 16A of the power storage device 16, and for example, N = 96 (pieces) in the present embodiment.

  FIG. 9 is a flowchart showing the processing function of the abnormality determination unit.

  In FIG. 9, the abnormality determination unit 230 reads the determination reference values A and B output from the determination reference value calculation unit 220 (step S231), and the determination reference value A is greater than or equal to a predetermined threshold Ath, and determination is made. It is determined whether the reference value B is equal to or greater than a predetermined threshold Bth (step S232). If the determination result in step S231 is YES, it is determined that an internal resistance abnormality (reversible resistance increase) has occurred in at least one of the plurality of battery cells C1 to C96 of the assembled battery 16A, and the generation of the internal resistance abnormality is The flag (abnormality flag) to be displayed is output to the monitor 5C and the output command unit 270 (step S233), and the process is ended. If the determination result in step S231 is NO, it is determined that an internal resistance abnormality has not occurred in the battery assembly 16A, and the process ends.

  When monitor 5C outputs an abnormality flag from abnormality determination unit 230, internal resistance abnormality (reversible resistance increase) occurs in power storage device 16 (more precisely, battery cells C1 to C96 of battery assembly 16A of power storage device 16). Display the information to be notified to the operator. Further, when the abnormality flag is output from abnormality determination unit 230, output command unit 270 calculates and outputs a control instruction to engine controller 12 and inverter 15 such that charge / discharge power of power storage device 16 is reduced. .

  Here, the determination principle of internal resistance abnormality (reversible resistance increase) will be described.

  The determination reference values A and B calculated by the determination reference value calculation unit 220 do not largely change each time they are calculated normally (that is, in the normal state). However, among the plurality of battery cells C1 to C96 constituting the assembled battery 16A, when the internal resistance of a specific battery cell becomes large (that is, an internal resistance abnormality such as increase in reversible resistance occurs), the determination reference values A and B Both values increase. That is, when the internal resistance of a specific battery cell increases, the fluctuation of the voltage of the battery cell at the time of current application also increases. Therefore, the highest cell voltage extraction value VCH in the above (formula 1) takes a higher value than that in normal. It will be. On the other hand, although the highest total voltage extraction value VTH is also increased by the increment of the highest cell voltage extraction value VCH, it is divided by the number N of the plurality of battery cells C1 to C96 constituting the assembled battery 16A, so (VTH / N) The increase is small. Therefore, as the internal resistance of a specific battery cell increases, the determination reference value A increases. Similarly, when the internal resistance of a specific battery cell increases, the determination reference value B also increases. Therefore, by monitoring the determination reference values A and B daily by the abnormality determination unit 230, it is possible to detect an increase in internal resistance of a specific battery cell.

  FIG. 10 is a diagram schematically showing an example of the date-to-date variation of the determination reference value, in which the vertical axis represents the determination reference value and the horizontal axis represents the date.

  In FIG. 10, the determination reference values A and B increase and decrease each time they are calculated, but for example, as in the case of the determination reference values A and B on the date D, the internal resistance of a specific battery cell is rapidly large. Then, the judgment reference values A and B both become extremely large. In such a case, when the determination reference values A and B simultaneously exceed predetermined threshold values Ath and Bth, respectively, it can be determined that an internal resistance abnormality has occurred.

  Next, a method of setting the thresholds Ath and Bth will be described.

  Here, taking the threshold Ath as an example, an example of a method of setting the value will be described. Threshold value Ath is determined according to the basic characteristics of battery cells C1 to C96 included in power storage device 16, the number of battery cells connected in multiple series, the magnitude of charge / discharge load current applied to power storage device 16, and the like. For example, consider a case where the storage device 16 is configured by connecting 100 battery cells in series, the rated voltage of each battery cell is 3.6 V, and the internal resistance of a normal battery cell without abnormality is 3 mΩ. Note that these values are numerical values that can be known in advance from the internal configuration of power storage device 16, the basic characteristics of the battery cell, and the like. In addition, while the hybrid shovel 100 (hybrid construction machine) is used daily, it is also possible to know in advance the current value to be charged / discharged to the storage device 16. Here, each battery when the charging current is 100A Consider cell voltage and total voltage.

  Assuming that the closed circuit voltage of each battery cell is 3.6 V and the maximum cell voltage extraction value VCH is recorded when the charging current is 100 A, the open circuit voltage of the cell having an internal resistance of 3 mΩ is 3.9 V. However, if one battery cell with an internal resistance of, for example, 1.4 times normal, ie, one battery cell with an internal resistance of 4.2 mΩ (ie, an abnormal cell in which an internal resistance abnormality has occurred), that battery cell The open circuit voltage of is 4.02 V, which is the highest cell voltage extraction value VCH. When the determination reference value A is obtained by the above (Equation 1) under such conditions, the reference determination value A ≒ 0.119 V is obtained. Similarly, when the determination reference value A when the internal resistance of the abnormal cell is 1.3 times that in the normal state is calculated, the determination reference value A 参照 0.089 V. Therefore, when it is determined that the internal resistance abnormality of the battery cell in which the internal resistance abnormality has occurred is determined to be abnormal when the internal resistance increases from 1.3 times to 1.4 times that of the normal battery cell, for example, the threshold Ath = 0.1V. It should be set. The normal / abnormal range of the internal resistance value of the battery cell can be obtained from the specification or the like of the battery cell to be used.

  The effects of the present embodiment configured as described above will be described.

  In the secondary battery, generally, the characteristic that the internal resistance is increased is known as the aged deterioration caused by the charge and discharge of the current and the storage. Such an increase in resistance is usually an irreversible increase in resistance (hereinafter referred to as an irreversible increase in resistance). On the other hand, in some secondary batteries, if charging and discharging of a large current is continuously carried out with respect to the capacity of the battery, a reversible increase in resistance (hereinafter referred to as "reversibility") different from the normal irreversible resistance increase. It is reported that if charging / discharging is performed in a state where the increase in the reversible resistance is occurring, deterioration of the secondary battery is promoted.

  With secondary batteries for hybrid construction machines, charging and discharging of large current is more likely to be continued as compared with secondary batteries for hybrid vehicles, etc., and it is expected that use in situations where reversible resistance increase is likely to occur . Therefore, as a prior art, there has been considered a control that detects an increase in the reversible resistance of the secondary battery to suppress acceleration of deterioration.

  However, in the prior art, it is difficult to apply the storage battery configuration in which a plurality of battery cells are connected in multiple series to a storage system. That is, in the above-mentioned prior art, when the storage system of the assembled battery configuration is viewed as one storage battery, it is possible to detect when the reversible resistance rise occurs uniformly in a plurality of battery cells constituting the storage battery. However, it is not considered to detect the increase in reversible resistance that occurs in some battery cells of the battery assembly configuration. Therefore, if the battery is continuously charged and discharged in a state where the increase in reversible resistance is generated without detecting the occurrence of the increase in reversible resistance in some of the battery cells of the assembled battery configuration, the battery cell is degraded. There is concern that it will be promoted.

  On the other hand, in the present embodiment, the engine 11, the motor generator 14 that assists the motive power of the engine at the time of power running, and the power generation at the time of regeneration, the hydraulic pump 17 driven by the engine 11, and the power storage device 16; In a hybrid shovel 100 provided with an inverter 15 for controlling transfer of electric power between the motor generator 14 and the storage device 16 and a hybrid controller 20 for controlling the operation of the inverter 15, multiple storage devices 16 are connected in series. A hybrid controller comprising: a battery assembly 16A constituted by a plurality of battery cells C1 to C96; a battery controller 16C monitoring a total voltage VT of the plurality of battery cells C1 to C96 of the battery assembly 16A; and a voltage of each battery cell 20 indicates the total voltage V of a plurality of battery cells from the monitoring result of the battery controller 16C. The highest total voltage extraction value VTH which is the highest value and the lowest total voltage extraction value VTL which is the lowest value within the first predetermined period of the battery cell, and the battery cell showing the highest voltage at a certain time point among the plurality of battery cells The highest cell voltage extraction value VCH which is the highest value within a predetermined first period of the highest cell voltage Vmax which is the voltage, and the lowest which is the voltage of the battery cell showing the voltage of the lowest value at a certain time among a plurality of battery cells Voltage information extraction unit 210 for extracting the lowest cell voltage extraction value VCL which is the lowest value in the first predetermined period of the cell voltage Vmin, and the highest total voltage extraction value VTH extracted by the voltage information extraction unit 210, the lowest Based on the total voltage extraction value VTL, the highest cell voltage extraction value VCH, and the lowest cell voltage extraction value VCL, internal resistance abnormalities of a plurality of battery cells of the power storage device are determined And at least one determination reference value A, B calculated by the determination reference value calculation unit 220 is greater than or equal to a predetermined threshold value Ath, Bth. And the abnormality determination unit 230 determines that an internal resistance abnormality has occurred in at least one of the plurality of battery cells of the assembled battery 16A, and therefore, the plurality of battery cells C1 to C96 are connected in series. It is possible to detect the increase in reversible resistance of some battery cells included in the assembled battery configuration.

  In addition, deterioration of the battery cells constituting the power storage device can be suppressed, and life extension can be realized, and the reliability of the power storage system of the hybrid type construction machine using the power storage device can be improved.

  In the present embodiment, two determination reference values A and B are calculated, and when both determination calculation values A and B exceed thresholds Ath and Bth, respectively, internal resistance abnormality (reversible resistance increase) is caused. However, the present invention is not limited to this, and may be configured to determine the occurrence of internal resistance abnormality (reversible resistance increase) when at least one determination calculation value exceeds a threshold.

Second Embodiment
A second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, only differences from the first embodiment will be described, and in the drawings, the same members as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

  The present embodiment is configured to determine the occurrence of internal resistance abnormality (reversible resistance increase) based on the amount of change of the determination reference value.

  FIG. 11 is a functional block diagram showing the details of the hybrid controller together with the related configuration.

  In FIG. 11, the hybrid controller 20A extracts a plurality of voltage information extracted by the voltage information extraction unit 210 which extracts voltage values respectively acquired under a plurality of predetermined conditions from the monitoring result of the battery controller 16C. A determination reference value calculation unit 220 that calculates at least one determination reference value A or B for determining internal resistance abnormality (reversible resistance increase) of the plurality of battery cells C1 to C96 of the assembled battery 16A based on the voltage value of And the calculation reference value storage unit 260 storing the judgment reference value calculated by the judgment reference value calculation unit 220, and the judgment reference values A and B calculated by the judgment reference value calculation unit 220 and the calculation value storage unit 260 Abnormality judgment to determine internal resistance abnormality occurring in at least one of the plurality of battery cells C1 to C96 of the assembled battery 16A based on the determined reference values A0 and B0 A system state determination unit 240 that determines the operating state (referred to as a system state) of the entire hybrid shovel 100 including the hybrid hydraulic circuit system 30 based on the state of the start switch 5D arranged in the cabin 230 and the unit 230A; It has an output command unit 270 that adjusts the output of the ECU 12 and the inverter 15 based on the determination result of the abnormality determination unit 230A.

  The calculation value storage unit 260 stores the determination reference values A and B calculated by the determination reference value calculation unit 220, and determines the final values of the determination reference values A and B before one operation day of the hybrid shovel 100. It is stored as reference values A0 and B0. That is, every time the date changes, the determination reference values A and B calculated last before the previous day are overwritten on the determination reference values A0 and B0 of the calculation value storage unit 260.

  FIG. 12 is a flowchart showing the processing function of the abnormality determination unit.

  12, abnormality determination unit 230A reads determination reference values A and B output from determination reference value calculation unit 220 (step S251), and reads calculation value storage unit 260 determination reference values A0 and B0 (step S252). ). Subsequently, reference determination value change amounts ΔA (= A−A0) and ΔB (= B−B0) are calculated (step S253), and determination reference value change amount ΔA is equal to or greater than a predetermined threshold value ΔAth, and determination is made. It is determined whether the reference value change amount ΔB is equal to or greater than a predetermined threshold value ΔBth (step S254). If the determination result in step S254 is YES, it is determined that an internal resistance abnormality (reversible resistance increase) has occurred in at least one of the plurality of battery cells C1 to C96 of the assembled battery 16A, and the generation of the internal resistance abnormality is The flag (abnormality flag) to be indicated is output to the monitor 5C and the output command unit 270 (step S255), and the process is ended. When the determination result in step S254 is NO, it is determined that the internal resistance abnormality has not occurred in the battery assembly 16A, and the process ends.

  FIG. 13 is a diagram schematically showing an example of the date-to-date variation of the determination reference value change amount, in which the vertical axis represents the determination reference value change amount and the horizontal axis represents the date.

  In FIG. 13, the determination reference value change amounts ΔA and ΔB increase and decrease as the calculation is performed, but the internal resistance of a specific battery cell, for example, as in the determination reference value change amounts ΔA and ΔB on date D. Becomes sharply larger than the previous operation time, the determination reference value change amounts ΔA and ΔB both become extremely large. In such a case, when the determination reference value change amounts ΔA and ΔB simultaneously exceed predetermined threshold values ΔAth and ΔBth, respectively, it can be determined that an internal resistance abnormality has occurred.

  The other configuration is the same as that of the first embodiment.

  The same effect as that of the first embodiment can be obtained also in the present embodiment configured as described above.

  In addition, since the occurrence of internal resistance abnormality is determined based on the amount of change of the determination reference value, suppressing the influence on the determination result of the increase in internal resistance as aged deterioration due to charge and discharge of current and storage. It is possible to more accurately determine the occurrence of reversible resistance rise (hereinafter referred to as reversible resistance rise) different from ordinary irreversible resistance rise.

  Next, the features of the above-described embodiments will be described.

  (1) In the above embodiment, the engine 11, the motor generator 14 that assists the power of the engine during power running and generates power during regeneration, the hydraulic pump 17 driven by the engine, the power storage device 16, A hybrid construction machine (for example, a hybrid shovel 100) comprising: an inverter 15 for controlling transfer of electric power between the motor generator and the storage device; and a hybrid controller 20 for controlling the operation of the inverter; 20A The storage device includes a battery assembly 16A configured of a plurality of battery cells C1 to C96 connected in multiple in series, and a battery controller 16C that monitors a total voltage of the plurality of battery cells of the battery assembly and a voltage of each battery cell. And the hybrid controller is configured to monitor the battery controller based on the monitoring result of the battery controller. The highest total voltage extraction value VTH which is the highest value within the first predetermined period of the total voltage of the battery cells and the lowest total voltage extraction value VTL which is the lowest value, and the predetermined cell voltages of the plurality of battery cells A voltage information extraction unit 210 for extracting the highest cell voltage extraction value VCH which is the highest value and the lowest cell voltage extraction value VCL which is the lowest value in the first period, and the highest total voltage extraction extracted by the voltage information extraction unit At least one determination reference value A, B for determining internal resistance abnormalities of a plurality of battery cells of the power storage device based on the value, the lowest total voltage extraction value, the highest cell voltage extraction value, and the lowest cell voltage extraction value And the assembled battery when the at least one determination reference value calculated by the determination reference value calculation unit 220 for calculating a value is greater than or equal to a predetermined threshold value Ath or Bth. It shall have a 230A; a plurality of abnormality determining unit 230 for determining the internal resistance abnormality has occurred in at least one battery cell.

  Thereby, the reversible resistance increase of a part of battery cells included in the assembled battery configuration in which the plurality of battery cells C1 to C96 are connected in multiple series can be detected.

  (2) Further, in the above-described embodiment, in the hybrid type construction machine of (1), the determination reference value calculation unit 220 determines the highest total voltage extraction value from the highest cell voltage extraction value as the plurality of battery cells And a value obtained by subtracting the lowest cell voltage extraction value from a value obtained by dividing the lowest total voltage extraction value by the number of the plurality of battery cells. A second determination reference value is calculated, and the abnormality determination unit determines that the first determination reference value is equal to or greater than a predetermined first threshold, and the second determination reference value is equal to or greater than a predetermined second threshold. In at least one case, it is determined that an internal resistance abnormality has occurred in at least one of the plurality of battery cells of the battery pack.

  (3) Further, in the above embodiment, in the hybrid construction machine of (1), the first determination is performed before the first period and finally calculated by the determination reference value calculation unit. The storage unit (for example, the calculation value storage unit 260) for storing the reference value and the second determination reference value, and the abnormality determination unit 230A performs the first period with respect to the first determination reference value stored in the storage unit. When the change amount ΔA of the first determination reference value A is equal to or more than a predetermined third threshold value ΔAth and the change of the second determination reference value B of the first period with respect to the second determination reference value stored in the storage unit It is determined that an internal resistance abnormality has occurred in at least one of the plurality of battery cells of the battery pack in at least one of the cases where the amount ΔB is equal to or greater than a predetermined fourth threshold ΔBth.

  Thereby, it is possible to suppress the influence on the determination result of the increase in internal resistance as aged deterioration due to charge and discharge of current and storage, and a reversible increase in resistance different from the ordinary increase in irreversible resistance (hereinafter, reversible The occurrence of a resistance increase can be determined more accurately.

<Supplementary Note>
The present invention is not limited to the above embodiments, and includes various modifications and combinations within the scope not departing from the gist of the present invention. Further, the present invention is not limited to the one provided with all the configurations described in the above embodiment, but also includes one in which a part of the configuration is deleted. In addition, each of the configurations, functions, and the like described above may be realized by designing a part or all of them with, for example, an integrated circuit. Further, each configuration, function, etc. described above may be realized by software by the processor interpreting and executing a program that realizes each function.

  2: Lower traveling body, 2A, 2A1, 2A2 ... Hydraulic motor for traveling (hydraulic actuator), 2B1, 2B2 ... Crawler frame, 2C1, 2C2 ... Crawler, 3: Upper revolving body, 3a ... Rotating frame, 3A ... Rotating device, 3A1 ... hydraulic motor for turning, 4 ... front work machine, 4a ... boom cylinder, 4A ... boom, 4b ... arm cylinder, 4B ... arm, 4c ... bucket cylinder, 4C ... bucket, 5 ... cabin, 5A ... operation lever device, 5B: Gate lock lever device, 5C: Monitor, 5D: Start switch, 6: Counter weight, 7: Motor room, 11: Engine, 12: Engine controller, 13: Auxiliary machine load, 14: Motor generator, 15: Inverter , 16: power storage device, 16A: assembled battery, 16B: current sensor, 16C: battery controller, 16 ... Voltage sensor, 17 ... Hydraulic pump, 18 ... Control valve, 20, 20 A ... Hybrid controller, 24 ... Deceleration mechanism, 30 ... Hybrid type hydraulic circuit system, 50 ... Operation system, 100 ... Hybrid shovel, 210 ... Voltage information extraction unit 211: maximum cell voltage extraction unit 212: minimum cell voltage extraction unit 213: maximum total voltage extraction unit 214: minimum total voltage extraction unit 220: determination reference value calculation unit 230, 230A: abnormality determination unit 240 ... System state determination unit, 260 ... Operation value storage unit, 270 ... Output command unit, battery cells C1 to C26, battery modules M1 to M8, cell controllers CC1 to CC8

Claims (3)

With the engine,
A motor generator that assists the power of the engine during power running and generates power during regeneration;
A hydraulic pump driven by the engine;
A storage device,
An inverter for controlling transfer of electric power between the motor generator and the storage device;
And a hybrid controller for controlling the operation of the inverter.
The storage device is
An assembled battery constituted by a plurality of battery cells connected in multiple series;
A battery controller monitoring a total voltage of the plurality of battery cells of the assembled battery and a voltage of each battery cell;
The hybrid controller
From the monitoring results of the battery controller, the highest total voltage extraction value which is the highest value in the first predetermined period of the total voltage of the plurality of battery cells and the lowest total voltage extraction value which is the lowest value A voltage information extraction unit for extracting the highest cell voltage extraction value which is the highest value and the lowest cell voltage extraction value which is the lowest value in the first predetermined period of the cell voltage of the cell;
Based on the highest total voltage extraction value, the lowest total voltage extraction value, the highest cell voltage extraction value, and the lowest cell voltage extraction value extracted by the voltage information extraction unit, internal resistance abnormalities of the plurality of battery cells of the power storage device are A determination reference value calculation unit that calculates at least one determination reference value for determination;
An abnormality that determines that internal resistance abnormality has occurred in at least one of the plurality of battery cells of the assembled battery when the at least one determination reference value calculated by the determination reference value calculation unit is equal to or greater than a predetermined threshold A hybrid-type construction machine characterized by having a determination unit. In the hybrid construction machine according to claim 1,
The determination reference value calculation unit is a first determination reference value that is a value obtained by subtracting a value obtained by dividing the highest total voltage extraction value by the number of the plurality of battery cells from the highest cell voltage extraction value, and the lowest total voltage Calculating a second determination reference value which is a value obtained by subtracting the lowest cell voltage extraction value from a value obtained by dividing the extraction value by the number of the plurality of battery cells;
The abnormality determination unit is configured to perform at least one of the case where the first determination reference value is greater than or equal to a predetermined first threshold and the case where the second determination reference value is greater than or equal to a predetermined second threshold. A hybrid construction machine characterized by determining that an internal resistance abnormality has occurred in at least one of a plurality of battery cells. In the hybrid construction machine according to claim 1,
And a storage unit that stores the first determination reference value and the second determination reference value that are calculated before the first period and finally at the determination reference value calculation unit.
The abnormality determination unit stores the change amount of the first determination reference value in the first period with respect to the first determination reference value stored in the storage unit in the storage unit and when the amount of change is equal to or more than a predetermined third threshold. At least one of the plurality of battery cells of the battery pack in at least one of the cases where the amount of change of the second determination reference value in the first period with respect to the second determination reference value is equal to or greater than a predetermined fourth threshold value. It is determined that an internal resistance abnormality has occurred in the hybrid construction machine.

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