JP7105665B2 - construction machinery - Google Patents

Description

The present invention relates to a power storage system that detects an abnormality in a power storage device and a power storage management system that manages the power storage system, and is suitable for technical fields such as hybrid construction machinery, for example.

In recent years, efforts have been made to electrify power sources mounted on mobile bodies such as construction machines. Electrification of the power source can be achieved by using a power storage device that stores electric power as a power source and driving an electric motor mounted on a moving object with the power supplied from the power storage device.

Power storage devices are configured using power storage elements such as secondary batteries such as lithium ion batteries, lead batteries, NAS batteries, and redox flow batteries, and capacitors such as electric double layer capacitors and lithium ion capacitors. Among them, the adoption of lithium-ion batteries with high input/output and high energy density is increasing. Further, in order to increase the capacity, the power storage device is configured by connecting a plurality of power storage elements in series and/or in parallel. A power storage system is configured by combining the power storage device and a control device such as a controller. In order to continue to use the energy storage system safely over a long period of time, the controller monitors the voltage, charging/discharging current, state of charge, etc., of each energy storage element, and ensures that each energy storage element is used within the appropriate usage range. need to control.

Here, in order to reduce the difference in the state of charge between the power storage elements connected in series, a balancing technique is known that adjusts and equalizes the state of charge of each power storage element. Patent Literature 1 discloses a configuration in which, based on information on a plurality of storage elements, a storage element having a high state of charge is selected and discharged so as to equalize (balance) the state of charge among the storage elements. .

Also disclosed is a method of determining an abnormality in a power storage device using balancing control information. Patent Document 2 discloses a technique for determining abnormality of a battery module itself by determining whether or not the amount of correction is within an appropriate range in a configuration including a correction unit that integrates and corrects the amount of power reduction due to natural discharge. is disclosed. Furthermore, Patent Literature 3 discloses a technique of calculating a predicted time for adjusting the state of charge from variations in the state of charge of a plurality of power storage elements, and determining the type of abnormality using the measured time required for the actual adjustment. ing.

U.S. Patent Application Publication No. 2009/0085516 JP 2016-102674 A Japanese Patent No. 5994240

In order to equalize the state of charge of each storage element, it is necessary to determine which storage element has an abnormal rate of decrease in the state of charge. However, there is a determination method based on the magnitude of the difference in the correction amount of the charging rate obtained based on the voltage as in Patent Document 2, and a prediction and actual measurement of the balancing time based on the voltage difference as in Patent Document 3. The determination method requires that the state of charge varies among the storage elements. It was difficult to detect whether there was an anomaly in the rate of state decline.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to detect an electric storage element having an abnormal rate of decrease in the state of charge without depending on the operating state of the electric storage system. .

In order to solve the above problems, one aspect of the present invention provides a hydraulic load driven by pressure oil from a hydraulic pump, a motor-generator that outputs power of the hydraulic pump, and an inverter that controls the motor-generator. a power storage device having a plurality of power storage elements connected in series and performing transfer of electric power to and from the motor-generator via the inverter and charging/discharging associated therewith; and an abnormality detecting an abnormality of the power storage device. In a construction machine comprising: a detection device; and a battery controller that performs a balancing operation to equalize differences in states of charge between the power storage elements, the abnormality detection device detects a plurality of the balancing operations performed by the battery controller. accumulative calculation of the history information of the balancing operation, and based on the accumulated result of the history information of the balancing operation, an abnormality in the rate of decrease in the state of charge of each storage element is determined, the result of the determination is output , and the history of the balancing operation is performed. The information includes the time of the balancing operation, the number of times of the balancing operation, the current value of charging or discharging of each storage element during the balancing operation, and the electric capacity of charging or discharging of each storage element during the balancing operation. wherein the abnormality detection device has a storage in which an abnormality determination reference value used for abnormality determination of each storage element is stored in advance, and the abnormality detection device stores a history of the balancing operation estimating an abnormality occurrence time at which an abnormality in the rate of decrease in the state of charge of each storage element occurs from an accumulation period of information, an accumulation result of the history information of the balancing operation, and the abnormality determination reference value stored in the storage; characterized by

ADVANTAGE OF THE INVENTION According to this invention, the electrical storage element which has abnormality in the fall speed of a charge state can be detected, without depending on the operating state of an electrical storage system. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a block diagram of a power storage system according to a first embodiment of the present invention; FIG. FIG. 4 is a diagram showing the relationship between the voltage of the storage element and the elapsed time when the storage system is not operated all the time (when operated infrequently). FIG. 4 is a diagram showing the relationship between the voltage of a power storage element and the elapsed time when the power storage system is operated all the time; FIG. 10 is a diagram showing an accumulation result of balancing information of an accumulation calculation unit; FIG. 10 is a diagram showing the relationship between the cumulative balancing capacity value of the X-th storage element and the abnormality determination reference value; It is a block diagram which shows the whole electrical storage management system structure which concerns on the 2nd Embodiment of this invention. FIG. 11 is a configuration diagram of a hybrid hydraulic excavator according to a third embodiment of the present invention; FIG. 11 is a functional block diagram of a hybrid hydraulic excavator according to a third embodiment; FIG. 6 is a diagram showing a case where arithmetic processing similar to that in FIG. 5 is performed and the X-th storage element is not determined to be abnormal; FIG. 10 is a diagram showing voltage transition of each storage element when the state of charge is set to high; FIG. 10 is a block diagram of a power storage system according to a fourth embodiment of the present invention; FIG. FIG. 11 is a block diagram of a power storage management system according to a fifth embodiment of the present invention;

Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In each figure, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

(First embodiment)
In the first embodiment, for example, a case where a power storage system according to the present invention is installed alone in a power plant using renewable energy or an electric power consumer will be described. FIG. 1 is a block diagram of a power storage system according to a first embodiment of the invention. In FIG. 1, a power storage system 1A includes a power storage device 10 configured by connecting n (two or more) power storage elements 10a, b, . . . 100 and a controller 105 that controls the operation of the power storage device 10 .

Here, the power storage device 10 has at least one function of charging or discharging each power storage element in order to reduce the difference in the state of charge between the power storage elements. Hereinafter, the operation of reducing the difference in the state of charge between the storage elements, that is, the operation of equalizing the state of charge between the storage elements is simply referred to as a balancing operation.

The abnormality detection device 100 has a processor 100A and a storage unit 103 (storage) connected thereto. The processor 100A includes a balancing information acquisition section 101, an accumulation calculation section 102, and a determination section 104, and the sections 101, 102, and 104 are connected. The processor 100A reads out various information stored in the storage unit 103 and executes various processes described later. The processor 100A is configured with hardware including a CPU, ROM, RAM, etc., and software, but may be configured with a circuit. Moreover, the storage unit 103 is configured by a storage medium such as a ROM, a RAM, and a nonvolatile memory.

Balancing information acquisition unit 101 collects information related to a balancing operation as information of power storage device 10 . Information related to the balancing operation (hereinafter referred to as balancing information) includes the balancing operation time, the number of balancing operations, the current value for charging or discharging each storage element during the balancing operation, and the charge or discharge rate for each storage element during the balancing operation. including at least one of capacitance. Note that the charging or discharging of each storage element during the balancing operation refers to charging or discharging that can be set for each storage element in order to equalize the charge state of the series-connected storage elements. It is different from charging or discharging which is common to all devices. The balancing information of power storage device 10 acquired by balancing information acquisition section 101 is transmitted to cumulative calculation section 102 , storage section 103 , and determination section 104 .

Based on the balancing information of the power storage device 10 acquired by the balancing information acquisition unit 101, the cumulative calculation unit 102 cumulatively calculates information on a plurality of balancing operations.

The storage unit 103 stores at least one of the accumulation results of the balancing information output from the balancing information acquisition unit 101 and the accumulation calculation unit 102 . Of course, the storage unit 103 may store both. The storage unit 103 can also store an abnormality determination reference value used by the determination unit 104 to determine whether the power storage element is abnormal. Note that FIG. 1 shows a configuration in which the accumulation result of the accumulation calculation unit 102 is stored in the storage unit 103, but the balancing information of the power storage device 10 acquired by the balancing information acquisition unit 101 is stored in the storage unit 103, and this balancing information is stored in the storage unit 103. Information may be used in the calculation of the cumulative calculation unit 102 . That is, the storage unit 103 stores the first balancing information acquired by the balancing information acquisition unit 101, and the cumulative calculation unit 102 reads out the first balancing information stored in the storage unit 103, and the balancing information acquisition unit The second and subsequent balancing information acquired by 101 can be directly input to perform cumulative calculation. Each time the balancing information acquisition unit 101 acquires the balancing information, the storage unit 103 stores all of the balancing information, and the cumulative calculation unit 102 reads the balancing information stored in the storage unit 103 for a plurality of times. A configuration for cumulative calculation may be used.

Determining unit 104 uses the cumulative result of the balancing information output from cumulative calculating unit 102 and the abnormality determination reference value stored in storage unit 103 to determine the plurality of power storage elements 10a, b . . . It is determined whether or not a storage element indicating an abnormality in the rate of decrease in the state of charge is included in the storage elements. The abnormality determination result by determination unit 104 is transmitted to controller 105 and reflected in the control of power storage device 10 . Further, the determination result of the presence or absence of abnormality in power storage device 10 output from determination unit 104 is input to output device 106 such as a monitor and a speaker, and transmitted to the user via output device 106 .

(Method for Determining Abnormality in State of Charge Decrease Rate of Storage Element)
FIG. 2 is a diagram showing the relationship between the voltage of the storage element and the elapsed time when the storage system is not operated all the time (when operated infrequently). In FIG. 2, the horizontal axis indicates the elapsed time, the vertical axis indicates the voltage, the dashed-dotted line indicates the data of the abnormal storage element, and the solid line indicates the data of the normal storage element. The abnormal power storage element (one-dot chain line) has a voltage drop linearly with the passage of time, and the state of charge decline speed is fast. On the other hand, in normal storage elements (solid line), the voltage drop is gradual except during balancing operation, but when the voltage difference in the storage system exceeds the threshold value for starting balancing operation, balancing discharges the high-voltage storage element. Through the operation, the voltage is equalized in a manner that matches the storage element with the lowest voltage (abnormal storage element).

While the energy storage system is in operation, the balancing operation is performed each time the voltage difference between the energy storage elements exceeds the threshold value for starting the balancing operation. Even if a large storage element exists, it will not be detected. However, if the non-operating period of the power storage system (during which the balancing operation is not performed) continues for a certain period of time or more, the voltage difference between the power storage elements in the power storage system increases. As a result, if the operation frequency of the power storage system is low, even the conventional technology can detect an abnormal power storage element.

FIG. 3 is a diagram showing the relationship between the voltage of the storage element and the elapsed time when the storage system is operated all the time. In the case of FIG. 3, the voltage difference between the power storage elements in the power storage system does not exceed the abnormality determination reference value as a result of the high frequency of the balancing operation. In such a case, the conventional technology does not detect an abnormal storage element. In addition, since the voltage difference in the power storage system does not increase, the voltage difference between the normal power storage element and the abnormal power storage element is small. , and there is a risk that the accuracy of the abnormality determination will be lowered. Furthermore, since the power storage system is charged and discharged during operation, the state of charge changes. If there is variation in the capacity of each storage element, the magnitude relationship in the state of charge changes as the charge and discharge progresses, and the voltage difference between the abnormal storage element and the normal storage element may become smaller. In the abnormality determination using only the difference, there is a possibility that the abnormality determination itself cannot be performed with high accuracy.

In order to solve such problems of the conventional technology, the present embodiment uses an abnormality determination method as described below. FIG. 4 is a diagram showing the result of accumulating balancing information by the accumulative calculation unit 102 in this embodiment. Note that this figure shows an example in which the balancing operation is performed by discharging. The horizontal axis indicates that n power storage elements are included in power storage device 10, and the vertical axis indicates the accumulated balancing capacity (electrical capacity) obtained by multiplying the balancing operation time by the discharge current of each power storage element. In addition to this, accumulation of the balancing operation time and accumulation of the number of balancing operations can be used for judging an abnormal storage element.

As shown in FIG. 3, the balancing operation (discharging) is not performed for the energy storage elements having an abnormal rate of decrease in the state of charge, and the balancing operation (discharging) is performed for the normal energy storage element group. Therefore, a storage element having an abnormal rate of state of charge decrease has a smaller accumulated balancing capacity value, like the X-th storage element in FIG. Based on this, the determining unit 104 determines that the X-th power storage element is abnormal from the cumulative value of the balancing information.

FIG. 5 is a diagram showing the relationship between the cumulative balancing capacity value of the X-th storage element and the abnormality determination reference value. As shown in FIG. 5, determination section 104 does not use the information of the storage element (X) with the smallest cumulative value, calculates the average value of the cumulative values of other storage elements, and calculates the average value of the storage elements with the smallest cumulative value. When the difference between the cumulative value and the average value of the element is larger than the abnormality determination reference value stored in the storage unit 103, it can be determined as abnormal. Of course, the difference between the maximum or minimum cumulative value of the storage elements other than the X-th storage element and the cumulative value of the X-th storage element may be used for abnormality determination. In addition, a known technique can be used for determination, using the median value of the cumulative values of all storage elements, or using the average of the cumulative values of all storage elements including the storage element (X) with the smallest cumulative value. Also good.

As described above, according to the first embodiment, by using the cumulative value (cumulative result) of the balancing capacity, which is an example of the balancing information, to determine whether the power storage element is abnormal, , n among the plurality of storage elements a, b, . . . , n.

Here, the period for performing the cumulative calculation can be arbitrarily set as long as it is common to all the storage elements included in the storage device 10 . Similarly, the start time and end time of this period can be set arbitrarily. It is preferable that the state of charge at the end time is substantially the same.

Further, in the present embodiment, the case where the balancing operation is performed by discharging has been described. Therefore, in FIGS. The cumulative value of balancing capacity showed a value smaller than that of the normal storage device. On the other hand, when the balancing operation is performed by charging, the voltage of the abnormal storage element increases during the balancing operation in FIGS. 2 and 3, and the accumulated data in FIGS. As a result, the accumulated balancing capacity value of the abnormal storage element is higher than that of the normal storage element. In addition, even when the balancing operation is performed by charging and discharging, the amount of charged electricity and the amount of discharged electricity can be differentiated and integrated, and a storage element with a large amount of charged electricity or a small amount of discharged electricity can be determined to be abnormal.

(Second embodiment)
Next, a second embodiment of the invention will be described. In the second embodiment, a power storage management system 110-1 in which a power storage system 1B and an external management device 112 are connected via a communication line 40 is illustrated. FIG. 6 is a block diagram showing the overall configuration of a power storage management system 110-1 according to the second embodiment of the present invention. As shown in FIG. 6, the power storage system 1B includes a first communication device 107 in addition to the configuration of the power storage system 1A shown in FIG. Also, the external management device 112 is connected to the second communication device 111, and information is transmitted and received between the first communication device 107 and the second communication device 111 via the communication line 40. there is

More specifically, in the power storage system 1</b>B shown in FIG. 6 , the abnormality determination result by the determination unit 104 is transmitted from the first communication device 107 to the second communication device 111 . The external management device 112 is composed of a server or the like capable of accumulating data and executing various types of arithmetic processing, and acquires and accumulates abnormality determination results via the second communication device 111 . Moreover, the abnormality determination result is output to the output device 106 such as a monitor so that the administrator of the power storage system 1B, the maintenance worker, or the like can know the abnormality determination result. Alternatively, the first communication device 107 can separately notify a predetermined terminal such as an administrator of the abnormality determination result via the communication line 40 . The communication line 40 may be wireless or wired.

Furthermore, the external management device 112 may receive and store balancing information output from the balancing information acquisition unit 101, the cumulative calculation unit 102, and the storage unit 103, in addition to the abnormality determination result by the determination unit 104. FIG. In this case, one of the abnormality detection device 100 and the external management device 112 cumulatively calculates the balancing information, and the other calculates the rate of decrease in the state of charge of each storage element a, b, . . . It can be configured to determine and output an abnormality. Alternatively, only the information output from the balancing information acquisition unit 101 may be received by the external management device 112, and the functions of the cumulative calculation unit 102, the storage unit 103, and the determination unit 104 may be performed remotely. With such a configuration, each of the plurality of power storage systems does not require the functions of the cumulative calculation unit 102, the storage unit 103, and the determination unit 104, and a simple power storage management system can be constructed as a whole. In addition, the output results of the cumulative calculation unit 102, the storage unit 103, and the determination unit 104 executed by the external management device 112 may be displayed on the external management device 112 and utilized. It may be communicated to the power storage system 1B via the first communication device 107 .

According to the power storage management system 110-1 described above, the abnormality determination of the power storage element is performed using the cumulative value of the balancing capacity, which is an example of the balancing information. It can be determined that the rate of decrease in the state of charge of the X-th storage element out of a, b, . . . n is abnormal. Moreover, since various data can be transmitted and received between the power storage system 1B and the external management device 112, management of the power storage system 1B is easy.

(Third embodiment)
The third embodiment exemplifies a hybrid hydraulic excavator (hybrid construction machine) equipped with the above-described power storage systems 1A and 1B. A hybrid hydraulic excavator according to a third embodiment will be described below with reference to the drawings. In the third embodiment, a hybrid hydraulic excavator equipped with a lithium ion battery will be described as an example, but the invention is not limited to this. For example, the present invention can be applied to various hybrid construction machines, such as hybrid wheel loaders and hybrid dump trucks, which are powered by the power of a hydraulic pump driven by an electric motor connected to a power storage device and an engine. In addition, the present invention can be applied to various types of electric construction machines powered by power storage devices, as well as to various types of machines having similar equipment configurations, such as electric trains, hybrid electric vehicles, plug-in hybrid electric vehicles, and electric vehicles. It is possible.

FIG. 7 is a configuration diagram of a hybrid hydraulic excavator 201 (hereinafter referred to as hybrid excavator 201) according to a third embodiment of the present invention. The hybrid excavator 201 includes a traveling body 212, a revolving body 213 provided on the traveling body 212 so as to be able to turn, and one side of the front portion of the revolving body 213 (on the right side when facing forward). and a front work machine 214 that rotates to perform work such as excavation. The traveling body 212, the revolving body 213, and the front working machine 214 all correspond to the "hydraulic load" of the present invention.

The revolving body 213 includes a cabin 215 arranged on the other side of the front (the left side when facing forward), a counterweight 216 arranged in the rear and maintaining the weight balance of the vehicle body, the cabin 215 and the counterweight 216. and a prime mover chamber 217 in which an engine 221, which will be described later, is housed.

FIG. 8 is a functional block diagram of a hybrid excavator 201 according to the third embodiment. The revolving body 213 includes the engine 221 described above, a fuel tank (not shown) that stores fuel for the engine 221, a governor (not shown) that adjusts the fuel injection amount of the engine 221, and the engine 221. It has a turbocharger (not shown) and an engine controller (engine control unit: ECU) 222 that controls the operation of the engine 221 .

Also, the revolving body 213 is connected to the engine 221 and arranged on the drive shaft of the engine 221 to transmit torque between the accessory load 223 such as an air conditioner that operates with the driving force of the engine 221 and the engine 221 . Thus, a motor generator (motor generator: M/G) 224 that assists and generates power for the engine 221, an inverter 225 that is connected to the motor generator 224 and controls the operation of the motor generator 224, and an inverter A power storage device 226 that transfers electric power to and from a motor-generator 224 via 225 is connected in series to the engine 221 and the motor-generator 224 and operates with the driving force of the engine 221 and the motor-generator 224. A variable displacement hydraulic pump (hereinafter referred to as a hydraulic pump for convenience) 227 that discharges pressure oil, and a pilot pump (not shown) that generates pilot pressure oil by operating with the driving force of the engine 221. It has

The motor-generator 224 assists the power of the engine 221 during power running, drives the auxiliary load 223 and the hydraulic pump 227 connected to the engine 221, and generates power during regeneration. The inverter 225 converts DC power into AC power and AC power into DC power. The power storage device 226 is connected, for example, between a battery cell group 226A formed by connecting a plurality of lithium ion batteries (power storage elements) in series and between the battery cell group 226A and the inverter 225. and a battery controller (battery control unit: BCU) 226C that is connected to the battery cell group 226A and the current sensor 226B and measures and manages the voltage, temperature, current, etc. of the battery cell group 226A. ,have.

The revolving body 213 is also connected to a control valve 220 that controls the flow (flow rate and direction) of pressure oil, an engine controller 222, an inverter 225, and a battery controller 226C, and controls the operation of a hydraulic pump 227 and an inverter 225. A hybrid controller (hybrid control unit: HCU) 229 is provided as a control device for controlling the overall operation.

The battery controller 226C AD-converts the measured value of the current sensor 226B, inputs it as a current, and measures each cell voltage and each cell temperature of the battery cell group 226A. Based on these currents, cell voltages, and cell temperatures, the state of charge of the battery cell group 226A, the maximum power that can be charged and discharged, and the balancing operation of the state of charge are performed. Then, these cell voltage, cell temperature, current, SOC (State of charge), allowable charge/discharge power, and balancing signal are transmitted to the hybrid controller 229 . The abnormality detection device 100 acquires the above various information and uses it for abnormality detection.

Although abnormality detection device 100 is shown independently of battery controller 226C and hybrid controller 229 in FIG. 8, battery controller 226C and hybrid controller 229 may have similar functions.

In such a configuration, the power storage system used in the hybrid excavator 201 has a charging/discharging method and an operation rate that vary greatly depending on the operator and circumstances such as construction work. In addition, there is a tendency for the number of parts to increase compared to the case where the power storage system is used alone as in the first and second embodiments, and the frequency and period of maintenance may become longer.

Based on such circumstances, in the third embodiment, when an abnormality of the storage element is determined, the determined abnormality is notified to the operator or maintenance personnel from the output device 106 (see FIGS. 1 and 6). be. This notification is made using a display on the monitor (informing device) 215A of the hybrid excavator 201 as shown in FIG. Leaving a power storage system containing an abnormal power storage element for a long period of time can cause troubles during operation. Therefore, it is preferable that the operator or maintenance staff who receives the notification promptly perform the balancing operation. Further, in terms of the operation plan, it is preferable to change the operation so that the non-operating period of the hybrid excavator 201 that has issued the notification does not continue.

Next, in the hybrid excavator 201 according to the third embodiment, a method of estimating in advance the time when an abnormality will become apparent will be described. FIG. 9 is a diagram showing a case where arithmetic processing similar to that in FIG. 5 is performed and the X-th storage element is not determined to be abnormal. In the example shown in this figure, the balancing operation is performed by discharging as in FIGS. 4 and 5, and the vertical axis is the accumulated balancing capacity value. Assuming that the period for accumulating the balancing capacity is T in this figure, the difference between the accumulated value of the X-th storage element and the average value of the other storage elements after the period T has passed is half the abnormality determination reference value. be.

From this determination result, determination unit 104 can estimate that the difference between the cumulative value of the X-th power storage element and the average value of the cumulative values of the other power storage elements reaches the abnormality determination reference value after period 2T has elapsed. can. The estimation result is notified to the user via the output device 106 and/or notified to the outside via the first communication device 107 (see FIGS. 1 and 6). At this time, it is preferable to reflect the time when the non-operating period 2T of the hybrid excavator 201 elapses in the maintenance plan as the abnormality occurrence time. That is, by restarting the operation before the period 2T elapses or by performing only the balancing operation before the period 2T elapses, the voltage difference between the abnormal storage element and the normal storage element expands to a predetermined value or more. This makes it possible to prevent the hybrid excavator 201 from being unable to operate due to an unexpected trouble (such as the generation of a maintenance alarm for the power storage device 10).

Furthermore, when performing maintenance work such as replacement of the battery cell group 226A, the replacement is performed before the period 2T elapses, thereby preventing the hybrid excavator 201 from being unable to operate due to unexpected trouble. Maintenance can be completed. It is preferable to notify the timing of resuming operation, the timing of performing only the balancing operation, and the timing of maintenance such as replacement of the battery cell group 226A by the output screen of the hybrid excavator 201 or communication means such as e-mail or telephone.

As described above, according to the third embodiment, the timing of occurrence of an abnormality in each storage element is estimated from the accumulated period of the balancing capacity, which is an example of the balancing information, the accumulated value of the balancing capacity, and the abnormality determination reference value. Therefore, it is possible to formulate planned operation and maintenance of the hybrid excavator 201 by referring to the estimated abnormality occurrence time. In addition, by performing a balancing operation, performing maintenance, etc. before the time when an abnormality occurs, it is possible to prevent an abnormal state of the storage element.

(Fourth embodiment)
In addition to the structure of 3rd Embodiment, 4th Embodiment illustrates the structure which utilizes the plan information of the operation of the hybrid excavator 201 for control of an electrical storage system.

In a situation where it is known by the processing in the third embodiment that the abnormality occurred at the time when the non-operating period 2T has elapsed, it is assumed that the non-operating period is, for example, 3T in the operation plan of the hybrid excavator 201. . In this embodiment, in such a case, the state of charge of the X-th storage element is set in advance to be higher than the other storage elements, thereby extending the period until an abnormality occurs and preventing an unexpected trouble from occurring. be able to.

FIG. 10 is a diagram showing changes in voltage of each storage element when the state of charge is set to high. FIG. 10 shows a state in which the voltage of the X-th storage element is set high by half the abnormality determination reference value at the elapsed time 0. In FIG. Although such a state can be realized by various means, it can be realized by discharging normal storage elements during the balancing operation. For example, when the elapsed time is 0, the storage elements other than the Xth storage element are discharged by an amount of electricity equivalent to half of the abnormality determination reference value, and then all storage elements are charged by an amount of electricity equivalent to half of the abnormality determination reference value. By doing so, the situation in FIG. 10 can be realized.

FIG. 11 is a block diagram of a power storage system 1C according to the fourth embodiment of the invention. First, the abnormality detection device 100 calculates the time when the balancing operation of the power storage device 10 is required (for example, when the non-operating period 2T, which is the time when an abnormality occurs/see FIG. 10) has elapsed. Next, the operator inputs the next operation time of the hybrid excavator 201 from the operation information input unit 108 . As a method for inputting the next operating time, the next operating date may be entered, or a period (for example, 3T) in which the hybrid excavator 201 does not operate may be entered. Then, based on the operation information from the operation information input unit 108, the abnormality detection device 100 outputs a command to the controller 105 to discharge the electric storage elements other than the X-th storage element by an amount of electricity equivalent to half of the abnormality determination reference value. , the X-th storage element is higher by half the voltage of the abnormality determination reference value, that is, the state at the elapsed time 0 in FIG. 10 can be realized.

Through the above process, the voltage of the X-th storage element is set higher by a voltage corresponding to half of the abnormality determination reference value for the amount of discharged electricity. As a result, it is possible to prevent the abnormality determination that occurs when 2T has elapsed until 3T has elapsed. In other words, the time at which an abnormality occurs can be delayed by the time corresponding to the difference between 3T and 2T. As a result, the cycle of the balancing operation and the maintenance cycle can be extended, and the operating efficiency of the hybrid excavator 201 is improved.

In this embodiment, in order to set the state of charge of the X-th storage element higher, the method of discharging the storage elements other than the X-th storage element is disclosed. A mechanism for charging the battery with a voltage corresponding to half may be provided. In addition, in the description so far and FIG. 10 , an example of one power storage element that is set to a high state of charge is shown, but if there are a plurality of power storage elements that indicate the state of charge deterioration rate abnormality, two or more power storage elements It is also possible to set a higher state of charge for the element.

(Fifth embodiment)
In the fifth embodiment, a power storage management system 110-2 constructed between a hybrid excavator 201 and an external management device 112 is illustrated. FIG. 12 is a block diagram of a power storage management system 110-2 according to the fifth embodiment of the present invention. A power storage system 1D shown in FIG. 12 has a configuration in which a first communication device 107 is added to the power storage system 1C shown in FIG. The external management device 112 is connected to the second communication device 111, and the operation information including the operation information of the hybrid excavator 201 is output from the abnormality detection device 100 via the first communication device 107 and the second communication device 111. Information can be stored on the external management device 112 .

Therefore, in the fifth embodiment as well, the accumulated value of the balancing information is used to determine whether the power storage device is abnormal. , it can be determined that the rate of decrease in the state of charge of the X-th storage element is abnormal. Moreover, since various data including operation information of the hybrid excavator 201 can be transmitted and received between the power storage system 1D and the external management device 112, management of the power storage system 1D is easy.

In the fifth embodiment, the working information input unit 108 is provided in the hybrid excavator 201, but the working information input unit 108 may be provided in the external management device 112, for example. This is convenient when the work site of the hybrid excavator 201 is far from the control room where the external control device 112 is installed.

The present invention is not limited to the first to fifth embodiments described above, and includes various modifications. For example, the first to fifth embodiments described above have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.

In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another modified example, and it is also possible to add the configuration of another modified example to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of the embodiment with another configuration. The main configuration of the present invention is to use the result of accumulating the balancing information for a plurality of times to determine whether the rate of decrease in the state of charge is abnormal. With this configuration, the determination accuracy is not affected by the voltage measurement accuracy or the like, unlike the case where an abnormality in the rate of decrease in the state of charge is determined from the balancing information for each time, and the operation rate of the storage system is high and balancing is frequently performed. Since the above-described abnormality can be determined even when there is no variation in the state of charge or the voltage, the above-described abnormality can be determined.

Note that the control lines and information lines are those considered to be necessary for explanation, and not all control lines and information lines are necessarily shown on the product. In fact, it may be considered that almost all configurations are interconnected.

1A to 1D power storage system 10 power storage device 10a to n power storage element 100 abnormality detection device 101 balancing information acquisition unit 102 cumulative calculation unit 103 storage unit (storage) 104 determination unit , 105... controller, 106... output device, 107... first communication device, 108... operation information input device, 110-1, 110-2... power storage management system, 111... second communication device, 112... external management device, 201 ... hybrid excavator (hybrid type construction machine), 212 ... running body (hydraulic load), 213 ... rotating body (hydraulic load), 214 ... front working machine (hydraulic load), 215A ... monitor (informing device), 221 ... engine, 224... Motor generator (M/G), 225... Inverter, 226... Power storage device, 226A... Battery cell group (power storage element), 226C... Battery controller (BCU), 227... Hydraulic pump, 229... Hybrid controller (HCU)

Claims (3)

hydraulic a hydraulic load driven by pressure oil from a pump, a motor-generator that outputs power of the hydraulic pump, an inverter that controls the motor-generator, and a plurality of power storage elements connected in series, An electric storage device that transfers electric power to and from the motor generator via an inverter and is charged and discharged accordingly, an abnormality detection device that detects an abnormality in the electric storage device, and equalizes the difference in the state of charge between the electric storage elements. a battery controller that performs balancing operations to allowconstruction machineryin
The abnormality detection device is
Accumulating history information of a plurality of times of the balancing operation by the battery controller, determining an abnormality in the rate of decrease in the state of charge of each storage element based on the accumulated result of the history information of the balancing operation, and determining the result of the determination outputsdeath,
The history information of the balancing operation includes the time of the balancing operation, the number of times of the balancing operation, the current value of charging or discharging of each storage element during the balancing operation, and the charging or discharging of each storage element during the balancing operation. including at least one of the discharge capacitancesfruit,
The abnormality detection device has a storage in which an abnormality determination reference value used for abnormality determination of each storage element is stored in advance,
The abnormality detection device detects a decrease in the state of charge of each storage element based on an accumulation period of the history information of the balancing operation, an accumulation result of the history information of the balancing operation, and the abnormality determination reference value stored in the storage. Characterized by estimating the abnormal occurrence time when the speed abnormality occursconstruction machinery. In the construction machine according to claim 1 ,
The battery controller, based on input operation information of the construction machine and the abnormality occurrence time estimated by the abnormality detection device, determines the power storage element that is estimated to cause the abnormality at the abnormality occurrence time. A construction machine characterized by presetting a high state of charge. In the construction machine according to claim 1 ,
The construction machine further comprises a notification device that notifies at least one of the abnormality occurrence time estimated by the abnormality detection device and the determination result of the abnormality of the power storage element determined by the abnormality detection device.

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