JP6808687B2 - Construction machinery - Google Patents

Description

The present invention relates to a construction machine including a power storage device.

A device is known that notifies an operator that a capacitor unit has deteriorated beyond a predetermined degree of deterioration in order to prevent the occurrence of a problem caused by the deterioration of the capacitor unit (see Patent Document 1).

JP-A-2007-155586

However, the apparatus of Patent Document 1 only discloses that when the deterioration degree of the capacitor unit reaches a predetermined deterioration degree, it notifies the fact, and the workability of the excavator when the deteriorated capacitor unit is used. There is no mention of technology to prevent the decline.

In view of the above, it is desirable to provide a construction machine capable of preventing a decrease in workability even when the power storage device deteriorates.

The construction machine according to the embodiment of the present invention is a construction machine including a power storage device, an electric motor driven by the electric power of the power storage device, and a control device, and the control device is used when the power storage device is deteriorated. The set value of the temperature of the power storage device is set to be relatively higher than that before the deterioration so that the temperature of the power storage device becomes high during the operation of the construction machine. When is deteriorated, it operates under the set value which is relatively higher than that before deterioration .

By the above-mentioned means, it is possible to provide a construction machine capable of preventing deterioration of workability even when the power storage device is deteriorated.

It is a side view of a hybrid excavator. It is a block diagram which shows the structure of the drive system of the hybrid excavator of FIG. It is a block diagram which shows the structure of a power storage system. It is a flowchart which shows the flow of the required value derivation process. It is a figure explaining an example of the SOC / required value correspondence table. It is a flowchart which shows the flow of the turning force running process. It is a flowchart which shows the flow of the process at the time of turning regeneration. It is a flowchart which shows the flow of the processing at the time of turning stop. It is a figure which shows another example of the SOC / required value correspondence table. It is a figure which shows the relationship between SOC of a capacitor and a turning speed limit value. It is a figure which shows the relationship between the turning speed limit value, the turning torque limit value, and the pump current limit value. It is a figure which shows the correspondence relationship between the temperature of a capacitor and the internal resistance. It is a figure which shows the example of the operation condition of a capacitor and a device related to a capacitor.

FIG. 1 is a side view showing a hybrid excavator which is an example of a construction machine according to an embodiment of the present invention. The upper swivel body 3 is mounted on the lower traveling body 1 of the hybrid excavator via the swivel mechanism 2. A boom 4 is attached to the upper swing body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6 is attached to the tip of the arm 5. The boom 4, arm 5, and bucket 6 form an excavation attachment, which is an example of the attachment, and are hydraulically driven by the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, respectively. The upper swing body 3 is provided with a cabin 10 and is equipped with a power source such as an engine 11.

FIG. 2 is a block diagram showing a configuration example of the drive system of the hybrid excavator of FIG. In FIG. 2, the mechanical power system is shown by a double line, the high-pressure hydraulic line is shown by a thick solid line, the pilot line is shown by a broken line, and the electric drive / control system is shown by a thin solid line.

The engine 11 and the motor generator 12 are connected to the two input shafts of the transmission 13, respectively. A main pump 14 and a pilot pump 15 as hydraulic pumps are connected to the output shaft of the transmission 13. A control valve 17 is connected to the main pump 14 via a high-pressure hydraulic line 16.

The control valve 17 is a control device that controls the hydraulic system in the hybrid excavator. Hydraulic actuators such as the right-side traveling hydraulic motor 1A, the left-side traveling hydraulic motor 1B, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 are connected to the control valve 17 via a high-pressure hydraulic line. The hydraulic system includes a right-side traveling hydraulic motor 1A, a left-side traveling hydraulic motor 1B, a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a main pump 14, and a control valve 17.

A power storage system 120 including a capacitor 19 as a power storage device is connected to the motor generator 12 via an inverter 18. As the power storage device, any means may be adopted as long as it is a means for storing electrical energy. Further, the turning electric motor 21 is connected to the power storage system 120 via the inverter 20. A resolver 22, a mechanical brake 23, and a swivel transmission 24 are connected to the rotary shaft 21A of the swivel motor 21. Further, the operating device 26 is connected to the pilot pump 15 via the pilot line 25.

The operating device 26 includes a lever 26A, a lever 26B, and a pedal 26C. The lever 26A, the lever 26B, and the pedal 26C are connected to the control valve 17 and the pressure sensor 29, respectively, via the hydraulic lines 27 and 28. The pressure sensor 29 is connected to a controller 30 that controls the drive of the electrical system.

FIG. 3 is a block diagram showing the configuration of the power storage system 120. The power storage system 120 includes a capacitor 19, a buck-boost converter 100, and a DC bus 110. The capacitor 19 includes an electric double layer capacitor, a lithium ion capacitor, a lithium ion battery and the like. In this embodiment, the capacitor 19 is a lithium ion capacitor. Further, the DC bus 110 controls the transfer of electric power between the capacitor 19, the motor generator 12, and the turning electric motor 21. The capacitor 19 is provided with a capacitor voltage detection unit 112 for detecting the capacitor voltage value and a capacitor current detection unit 113 for detecting the capacitor current value. The capacitor voltage value and the capacitor current value detected by the capacitor voltage detection unit 112 and the capacitor current detection unit 113 are supplied to the controller 30.

Specifically, the capacitor voltage value corresponds to the terminal voltage of the capacitor 19. Then, assuming that the open circuit voltage of the capacitor 19 is Vc [V], the internal resistance of the capacitor 19 is R [Ω], and the magnitude of the discharge current flowing from the capacitor 19 to the buck-boost converter 100 is Id [A], the capacitor 19 The terminal voltage V1 at the time of discharging is represented by V1 = Vc−R × Id, and the discharge power W1 of the capacitor 19 is represented by W1 = V1 × Id. Further, assuming that the magnitude of the charging current flowing from the buck-boost converter 100 to the capacitor 19 is Ic, the terminal voltage V2 at the time of charging the capacitor 19 is represented by V2 = Vc + R × Ic, and the charging power W2 of the capacitor 19 is W2. = V2 × Ic.

Further, the calorific value Q1 at the time of discharging the capacitor 19 is represented by Id ² × R, and the calorific value Q2 at the time of charging is represented by Ic ² × R.

The charge rate (SOC) of the capacitor 19 is expressed by the following equation, where Vmin is the minimum voltage of the capacitor 19 and Vmax is the maximum voltage.

以上の関係から、キャパシタ１９のＳＯＣが高いことは開放電圧Ｖｃが高いことを意味し、所定の放電電力Ｗ１を実現する場合の放電電流Ｉｄが小さくて済み、放電時の発熱量Ｑ１も小さくなるため、放電効率が高いことが分かる。同様に、所定の充電電力Ｗ２を実現する場合の充電電流Ｉｃが小さくて済み、充電時の発熱量Ｑ２も小さくなるため、充電効率が高いことが分かる。

From the above relationship, a high SOC of the capacitor 19 means a high open circuit voltage Vc, the discharge current Id when the predetermined discharge power W1 is realized can be small, and the calorific value Q1 at the time of discharge is also small. Therefore, it can be seen that the discharge efficiency is high. Similarly, it can be seen that the charging efficiency is high because the charging current Ic when the predetermined charging power W2 is realized is small and the calorific value Q2 at the time of charging is also small.

Further, the capacitor 19 is provided with a temperature sensor M2 as a temperature detection unit for detecting the temperature of the capacitor 19 (capacitor temperature). Further, the buck-boost converter 100 is also provided with a temperature sensor M3 as a temperature detection unit for detecting the temperature of the buck-boost converter 100. The temperature sensor M2 and the temperature sensor M3 are composed of, for example, a thermistor, and output each detected value to the controller 30. Further, the capacitor temperature may be indirectly detected by detecting the temperature of the cooling water used for cooling the capacitor 19. Further, the capacitor temperature may be indirectly detected from the temperature of the housing on which the capacitor 19 is mounted, the ambient temperature inside or outside the housing, and the like.

The buck-boost converter 100 controls to switch between a step-up operation and a step-down operation so that the DC bus voltage value falls within a certain range according to the operating state of the motor generator 12 and the turning electric motor 21. The DC bus 110 is arranged between the inverters 18 and 20 and the buck-boost converter 100, and transfers power between the capacitor 19, the motor generator 12, and the turning electric motor 21.

The controller 30 is a control device as a main control unit that controls the drive of the hybrid excavator. In this embodiment, the controller 30 is composed of a CPU and an arithmetic processing device including an internal memory, and various functions are realized by the CPU executing a drive control program stored in the internal memory. The various functions include functions corresponding to each of the deterioration degree acquisition unit 31, the operation condition changing unit 32, and the operation control unit 33 as functional elements included in the controller 30. The details of the deterioration degree acquisition unit 31, the operation condition changing unit 32, and the operation control unit 33 will be described later.

Further, the controller 30 converts the signal supplied from the pressure sensor 29 into a speed command, and controls the drive of the turning electric motor 21. The signal supplied from the pressure sensor 29 corresponds to a signal representing an operation amount when the operation device 26 is operated to rotate the rotation mechanism 2.

Further, the controller 30 controls the operation of the motor generator 12 (switching between electric (assist) operation and power generation operation), and also controls the charge / discharge of the capacitor 19 by driving and controlling the buck-boost converter 100. Further, the controller 30 uses the buck-boost converter 100 based on the charging state of the capacitor 19, the operating state of the motor generator 12 (assist operation or power generation operation), and the operating state of the turning motor 21 (power running operation or regenerative operation). It controls switching between the step-up operation and the step-down operation, thereby controlling the charging and discharging of the capacitor 19.

The switching control between the step-up operation and the step-down operation of the buck-boost converter 100 is performed by the DC bus voltage value detected by the DC bus voltage detection unit 111, the capacitor voltage value detected by the capacitor voltage detection unit 112, and the capacitor current detection unit 113. It is done based on the capacitor current value detected by. In this case, the controller 30 may execute voltage control for controlling the DC bus voltage value within a predetermined range by the buck-boost converter 100. Specifically, the capacitor 19 may be charged and discharged so as to absorb the fluctuation of the DC bus voltage value due to the assist operation or power generation operation of the motor generator 12 or the power running operation or regenerative operation of the turning motor 21. Further, the buck-boost converter 100 cooperates with a controller other than the controller 30 via communication, and adjusts the capacitor 19 according to the assist operation or power generation operation of the motor generator 12 or the power running operation or regenerative operation of the turning motor 21. It may be charged and discharged.

In the above configuration, the electric power generated by the motor generator 12 is supplied to the DC bus 110 of the power storage system 120 via the inverter 18 and then supplied to the capacitor 19 via the buck-boost converter 100, or It is supplied to the turning motor 21 via the inverter 20. Further, the regenerative power generated by the regenerative operation of the turning motor 21 is supplied to the DC bus 110 of the power storage system 120 via the inverter 20 and then supplied to the capacitor 19 via the buck-boost converter 100, or It is supplied to the motor generator 12 via the inverter 18. Further, the electric power stored in the capacitor 19 is supplied to at least one of the motor generator 12 and the turning electric motor 21 via the buck-boost converter 100 and the DC bus 110. In this embodiment, the turning motor 21 preferentially uses the electric power stored in the capacitor 19, and the electric power generated by the motor generator 12 is used as an auxiliary.

In the hybrid excavator having the above-described configuration, the controller 30 charges and discharges the capacitor 19 so that the capacitor 19 can maintain a predetermined charge rate (SOC).

The controller 30 determines the charge request value (corresponding to the charge amount) and the discharge request value (corresponds to the discharge amount) based on the current value of the SOC of the capacitor 19, and controls the charging / discharging of the capacitor 19. In this embodiment, the charge request value means the maximum value of the generated power received by the capacitor 19. Further, the discharge required value means the maximum value of the electric power supplied by the capacitor 19 to the turning electric motor 21. When the charge request value is a negative value other than zero (in this embodiment, the charge power is a negative value and the discharge power is a positive value), the controller 30 causes the electric generator 12 to function as a generator. Then, the motor generator 12 is made to generate electric power with an output equal to or higher than the electric power corresponding to the charging required value, and the capacitor 19 is charged with the electric power corresponding to the charging required value. Further, the controller 30 does not charge the capacitor 19 when the charge request value is set to zero. Therefore, the motor generator 12 does not function as a generator only for charging the capacitor 19. However, it is not prohibited to make the motor generator 12 function as a generator for other purposes.

Further, when the discharge request value is set to a positive value other than zero, the controller 30 causes the motor generator 12 to function as an electric motor. Then, the motor generator 12 is assisted with an output equal to or higher than the power corresponding to the required discharge value, and the capacitor 19 is discharged with the power corresponding to the required discharge value. When the turning electric motor 21 is in power running operation, the controller 30 discharges the electric power of the capacitor 19 toward the turning electric motor 21 with a power corresponding to the discharge request value. In this case, if the output [kW] required to drive the turning motor 21 is larger than the power corresponding to the discharge request value, the controller 30 causes the motor generator 12 to function as a generator instead of a motor. This is because the turning motor 21 is driven by the power generated by the motor generator 12 and the power discharged by the capacitor 19. Further, the controller 30 does not discharge the capacitor 19 when the discharge request value is set to zero. Therefore, the motor generator 12 does not function as an electric motor only for discharging the capacitor 19, and the electric power of the capacitor 19 is not discharged toward the turning electric motor 21.

Here, with reference to FIG. 4, a process in which the controller 30 derives a charge request value and a discharge request value based on the SOC of the capacitor 19 (hereinafter, referred to as “request value derivation process”) will be described. Note that FIG. 4 is a flowchart showing the flow of the required value derivation process, and the controller 30 repeatedly executes the required value derivation process at a predetermined control cycle.

First, the controller 30 acquires the SOC of the capacitor 19 (step S1). In this embodiment, the controller 30 calculates the SOC based on the capacitor voltage value detected by the capacitor voltage detection unit 112 and the capacitor current value detected by the capacitor current detection unit 113.

Further, the controller 30 detects the state of the turning electric motor 21 (step S2). In this embodiment, the controller 30 determines the operating state and the stopped state of the turning electric motor 21 from the turning speed calculated based on the output of the resolver 22. Further, the controller 30 determines the power running state and the regenerative operation state of the turning electric motor 21 from the turning torque and the turning speed calculated based on the current flowing through the inverter 20.

Further, steps S1 and S2 are in no particular order, and the controller 30 may acquire the SOC of the capacitor 19 after detecting the state of the swivel motor 21, or may execute the two processes at the same time.

After that, the controller 30 derives a charging request value based on the SOC of the capacitor 19 and the state of the turning electric motor 21 (step S3). In this embodiment, the controller 30 refers to the SOC / request value correspondence table stored in the internal memory, and derives the charge request value based on the current SOC and the current state of the swivel motor 21.

Further, the controller 30 derives a discharge request value based on the SOC of the capacitor 19 and the state of the turning electric motor 21 (step S4). In this embodiment, the controller 30 refers to the SOC / required value correspondence table used when deriving the charging required value, and derives the discharge required value based on the current SOC and the current state of the turning electric motor 21.

FIG. 5 is a diagram illustrating an example of a SOC / required value correspondence table. Specifically, FIG. 5 is a graph showing the relationship between the SOC of the capacitor 19 and the discharge request value and the charge request value. The horizontal axis corresponds to the SOC [%], and the vertical axis corresponds to the required value. In FIG. 5, the discharge request value is a positive value, and the charge request value is a negative value. Further, the charging request value in FIG. 5 is for causing the motor generator 12 to function as a generator for charging the capacitor 19, and does not require charging by the regenerative power of the turning motor 21. The regenerative power of the turning motor 21 is charged to the capacitor 19 separately from the charging by the generated power of the motor generator 12 according to the charging request value.

Further, the charging request line CL1 shown by the broken line in FIG. 5 represents the transition of the charging request value adopted when the turning motor 21 is in the power running state, and the charging request line CL2 shown by the alternate long and short dash line in FIG. 5 is turning. The change in the charge request value adopted when the motor 21 is in the regenerative operation state is shown, and the charge request line CL3 indicated by the alternate long and short dash line is the change in the charge request value adopted when the turning electric motor 21 is in the stopped state. Represents.

Further, the discharge request line DL1 shown by the broken line in FIG. 5 represents the transition of the discharge request value adopted when the turning motor 21 is in the power running state, and the discharge request line DL2 shown by the alternate long and short dash line in FIG. 5 is turning. The discharge request line DL3 shown by the alternate long and short dash line represents the transition of the discharge request value adopted when the motor 21 is in the regenerative operation state, and the discharge request value DL3 adopted when the turning motor 21 is in the stopped state. Represents.

Specifically, the charge request line CL1 has a charge request value of C1 when the SOC is 40 [%] or less, and gradually becomes zero until the SOC exceeds 40 [%] and reaches 45 [%]. It means that the value becomes zero when the SOC approaches 45 [%] or more. By adopting the charge request line CL1, the controller 30 sets the capacitor 19 so that the SOC of less than 45 [%] becomes 45 [%] while preventing the terminal voltage of the capacitor 19 from exceeding the upper limit voltage during turning force running. Let it charge. The same applies to the charging request line CL2 and the charging request line CL3.

Further, the discharge request line DL1 has a discharge request value of zero when the SOC is 60 [%] or less, and increases at a constant rate until the SOC exceeds 60 [%] and reaches 100 [%], and the SOC increases. Indicates that the value D1 is obtained when the value reaches 100 [%]. By adopting the discharge request line DL1, the controller 30 sets the capacitor 19 so that the SOC of 60 [%] or more becomes 60 [%] while preventing the terminal voltage of the capacitor 19 from falling below the lower limit voltage during turning force running. Discharge. The same applies to the discharge request line DL2 and the discharge request line DL3.

Next, referring to FIG. 6, when the turning electric motor 21 is in the power running state, the controller 30 controls the charging / discharging of the capacitor 19 by using the charging required value and the discharging required value (hereinafter, “swinging power running”). Time processing ”) will be described. Note that FIG. 6 is a flowchart showing the flow of the turning force running process, and the controller 30 repeatedly executes the turning force running process at a predetermined control cycle when the turning electric motor 21 is in the power running state. The controller 30 may execute this turning force running process only once at the start of turning force running.

First, the controller 30 determines whether or not the output required for turning drive of the turning electric motor 21 (hereinafter, referred to as “required output”) is equal to or less than the required discharge value (step S11). In this embodiment, the controller 30 derives the required output from the product of the turning speed calculated based on the output of the resolver 22 and the turning torque calculated based on the current flowing through the inverter 20. Then, the controller 30 compares the required output with the discharge request value derived by the request value derivation process.

When it is determined that the required output is equal to or less than the required discharge value (YES in step S11), the controller 30 drives the turning electric motor 21 only with the electric power (discharge power) that the capacitor 19 discharges (step S12). Specifically, when the required output is low as in the initial stage of power running operation, the controller 30 drives the turning electric motor 21 only with the discharge power.

On the other hand, when it is determined that the required output is larger than the discharge request value (NO in step S11), the controller 30 determines whether or not the charge request value is zero (step S13). In this embodiment, it is determined whether or not the charge request value is zero by referring to the charge request value derived by the request value derivation process. A charging request value of zero means that charging of the capacitor 19 is stopped.

When it is determined that the charge request value is zero (YES in step S13), the controller 30 determines whether or not the required output is equal to or less than the sum of the discharge request value and the power generation limit value (step S14). The power generation limit value means the maximum value of the electric power that the motor generator 12 can generate.

When it is determined that the required output is equal to or less than the sum of the discharge request value and the power generation limit value (YES in step S14), the controller 30 determines whether or not the discharge request value is zero (step S15). A discharge request value of zero means that the discharge of the capacitor 19 is stopped.

When it is determined that the discharge request value is zero (YES in step S15), that is, when the discharge of the capacitor 19 is stopped, the controller 30 uses only the power generated by the motor generator 12 (generated power). The turning motor 21 is driven (step S16).

Further, when it is determined that the discharge request value is not zero (NO in step S15), that is, when the discharge of the capacitor 19 is not stopped, the controller 30 determines that the discharge power discharged by the capacitor 19 and the motor generator 12 are used. The turning motor 21 is driven by the generated power (step S17).

Specifically, the controller 30 suppresses the discharge power and increases the generated power as the SOC decreases. Therefore, the controller 30 can realize a relatively high terminal voltage and a relatively low discharge current by maintaining the SOC in a high state, and can achieve high efficiency.

Further, when it is determined that the required output is larger than the sum of the discharge request value and the power generation limit value (NO in step S14), the controller 30 has a discharge power larger than the discharge power corresponding to the discharge request value discharged by the capacitor 19 and an electric motor. The turning motor 21 is driven by the generated power corresponding to the power generation limit value generated by the generator 12 (step S19). This is because the required output required by the swivel motor 21 cannot be supplied by the generated power corresponding to the power generation limit value and the discharge power corresponding to the required discharge value.

Further, when it is determined that the charge request value is not zero (NO in step S13), that is, when the charging of the capacitor 19 is not stopped, the controller 30 subtracts the charge request value from the power generation limit value for the required output. It is determined whether or not it is equal to or greater than the value (step S18).

When it is determined that the required output is equal to or greater than the value obtained by subtracting the charge request value from the power generation limit value (YES in step S18), the controller 30 determines that the discharge power is larger than the discharge power corresponding to the discharge request value discharged by the capacitor 19. The turning motor 21 is driven by the generated power corresponding to the power generation limit value generated by the motor generator 12 (step S19). When the capacitor 19 is charged with the generated power equivalent to the charging required value generated by the motor generator 12, the capacitor 19 cannot be discharged, and the motor generator 12 alone cannot supply the required output required by the turning motor 21. Is.

On the other hand, when it is determined that the required output is less than the value obtained by subtracting the charge request value from the power generation limit value (NO in step S18), the controller 30 uses only the generated power generated by the motor generator 12 to generate the turning motor 21. The capacitor 19 is charged with the generated power corresponding to the charging required value generated by the motor generator 12 (step S20). That is, the motor generator 12 generates electric power corresponding to the required output and electric power corresponding to the required charging value.

By repeatedly executing the above-mentioned turning force running process, the controller 30 sets the SOC (for example, a value larger than 60%) corresponding to the discharge request value other than zero as the capacitor 19 as shown by the discharge request line DL1 in FIG. In the case of, if the required output is equal to or less than the required discharge value, the turning electric motor 21 is driven only by the discharge power discharged by the capacitor 19. Further, when the capacitor 19 indicates an SOC (for example, a value larger than 60%) corresponding to a discharge request value other than zero, if the required output is larger than the discharge request value, the discharge power corresponding to the discharge request value discharged by the capacitor 19 is obtained. The turning motor 21 is driven by the generated power generated by the motor generator 12. In this way, the controller 30 positively discharges the capacitor 19 during the turning force running, so that the regenerative power generated during the subsequent turning regeneration can be reliably charged to the capacitor 19.

Further, when the capacitor 19 indicates an SOC (for example, a value of 60% or less) corresponding to a discharge request value of zero, the turning motor 21 is driven only by the generated power generated by the motor generator 12. Further, when the capacitor 19 indicates an SOC (for example, a value of 45% or less) corresponding to a discharge request value of zero, the controller 30 drives the turning motor 21 only with the generated power generated by the motor generator 12. Further, the motor generator 12 is made to generate the generated power corresponding to the charging required value, and the generated power is charged into the capacitor 19. In this way, for example, when the discharge of the capacitor 19 for making the motor generator 12 function as an electric motor increases and the SOC of the capacitor 19 is low in order to keep the load of the engine 11 constant. By charging the capacitor 19 even when the turning force is running, over-discharging of the capacitor 19 is prevented.

Next, with reference to FIG. 7, when the turning electric motor 21 is in the regenerative operation state, the controller 30 controls the charging / discharging of the capacitor 19 by using the charge request value and the discharge request value (hereinafter, “swing regeneration”). “Time processing”) will be described. Note that FIG. 7 is a flowchart showing the flow of the swivel regeneration process, and the controller 30 repeatedly executes the swivel regeneration process at a predetermined control cycle when the swivel motor 21 is in the regenerative operation state.

First, the controller 30 determines whether or not the discharge request value is zero (step S21).

When it is determined that the discharge request value is zero (YES in step S21), that is, when the discharge of the capacitor 19 is stopped, the controller 30 determines whether or not the charge request value is not zero (YES). Step S22).

When it is determined that the charge request value is not zero (YES in step S22), that is, when the charging of the capacitor 19 is not stopped, the controller 30 determines all the regenerative power regenerated by the turning electric motor 21 and the charge request value. The capacitor 19 is charged with the electric power corresponding to (step S23).

When it is determined that the charge request value is zero (NO in step S22), that is, when the charging of the capacitor 19 is stopped, the controller 30 uses all the regenerative power regenerated by the turning electric motor 21. The capacitor 19 is charged (step S24).

Further, when it is determined that the discharge request value is not zero (NO in step S21), that is, when the discharge of the capacitor 19 is not stopped, the controller 30 determines whether or not the regenerative power is larger than the discharge request value. (Step S25). In this embodiment, the regenerative power is represented by a negative value, and the discharge request value is represented by a positive value. Therefore, strictly speaking, the controller 30 determines whether or not the absolute value of the regenerative power is larger than the discharge request value.

When it is determined that the regenerative power is larger than the discharge request value (YES in step S25), the controller 30 charges the capacitor 19 by the difference between the regenerative power and the power corresponding to the discharge request value (step S26). In this embodiment, the controller 30 supplies a part of the regenerative power corresponding to the discharge request value from the turning motor 21 to the motor generator 12 to make the motor generator 12 function as an electric motor, and the remaining part of the regenerative power. To charge the capacitor 19.

On the other hand, when it is determined that the regenerative power is equal to or less than the discharge request value (NO in step S25), the controller 30 directs the sum of the regenerative power and the power corresponding to the discharge request value to the motor generator 12 (step S27). ). In this embodiment, the controller 30 supplies all of the regenerated electric power from the turning motor 21 to the motor generator 12, and supplies power corresponding to the discharge required value from the capacitor 19 to the motor generator 12 to generate electric power. The machine 12 is made to function as a motor.

In this embodiment, the electric power that can be accepted by the motor generator 12 that functions as an electric motor is limited by a predetermined assist limit value. In this case, the assist limit value means the maximum value of electric power that can be accepted by the motor generator 12 that functions as an electric motor. This is to prevent the engine 11 from blowing up due to the assist output becoming too large. Therefore, when the sum of the regenerative power and the power corresponding to the discharge request value exceeds the power corresponding to the assist limit value, the controller 30 reduces the power corresponding to the discharge request value, that is, is discharged from the capacitor 19. By reducing the power generated, the power supplied to the motor generator 12 is made equal to the power corresponding to the assist limit value.

When the capacitor 19 indicates the SOC (for example, 30%) corresponding to the discharge request value of zero, as shown by the charge request line CL2 in FIG. 5, the controller 30 repeatedly executes the above-mentioned swirl regeneration process. , All of the regenerative power is supplied to the capacitor 19 to charge the capacitor 19, and the electric generator 12 generates power corresponding to the charging required value, and the generated power is used to charge the capacitor 19. In this way, when the SOC of the capacitor 19 is in a low state, the controller 30 causes the motor generator 12 to generate power to charge the capacitor 19 even during regenerative braking, thereby raising the SOC to a high state. return.

Further, as shown by the discharge request line DL2 in FIG. 5, when the capacitor 19 indicates the SOC (for example, a value larger than 70%) corresponding to the discharge request value other than zero, the magnitude of the regenerative power is the magnitude of the discharge request value. If it is larger than that, the capacitor 19 is charged with the differential power, and the power corresponding to the required discharge value is supplied from the turning motor 21 to the motor generator 12 to make the motor generator 12 function as an electric motor. In this way, the controller 30 prevents the capacitor 19 from being overcharged by consuming a part of the regenerative power in the motor generator 12 even when a large regenerative power is generated by turning 180 degrees or the like. To do.

Further, when the capacitor 19 indicates an SOC (for example, a value larger than 70%) corresponding to a discharge request value other than zero, if the magnitude of the regenerative power is equal to or less than the discharge request value, the discharge request value of zero value The sum of the regenerated electric power and the electric power corresponding to the required discharge value is directed to the motor generator 12 until the SOC corresponding to the above (for example, 70%) is reached, and the motor generator 12 functions as an electric motor. In this way, the controller 30 prevents the capacitor 19 from being overcharged.

Next, referring to FIG. 8, a process in which the controller 30 controls charging / discharging of the capacitor 19 by using the charge request value and the discharge request value when the turning electric motor 21 is stopped (hereinafter, “when turning is stopped”). "Processing") will be described. Note that FIG. 8 is a flowchart showing the flow of the turning stop processing, and the controller 30 repeatedly executes the turning stop processing in a predetermined control cycle when the turning electric motor 21 is in the stopped state.

First, the controller 30 determines whether or not the discharge request value is zero (step S31).

When it is determined that the discharge request value is zero (YES in step S31), that is, when the discharge of the capacitor 19 is stopped, the controller 30 determines whether or not the charge request value is not zero (YES). Step S32).

When it is determined that the charge request value is not zero (YES in step S32), that is, when the charging of the capacitor 19 is not stopped, the controller 30 causes the electric generator 12 to function as a generator, and the electric generator 12 The capacitor 19 is charged with the generated power generated by (step S33).

When it is determined that the charge request value is zero (NO in step S32), that is, when the charging of the capacitor 19 is stopped, the controller 30 does not charge the capacitor 19. Therefore, the motor generator 12 does not function as a generator only for charging the capacitor 19. However, it is not prohibited to make the motor generator 12 function as a generator for other purposes.

On the other hand, when it is determined that the discharge request value is not zero (NO in step S31), that is, when the discharge of the capacitor 19 is not stopped, the controller 30 drives the motor generator 12 with the electric power discharged by the capacitor 19. (Step S34).

By repeatedly executing the above-mentioned rotation stop processing, the controller 30 uses the capacitor 19 indicating the SOC (for example, 30%) corresponding to the non-zero charge request value as shown by the charge request line CL3 in FIG. It is charged to the SOC (for example, 60%) corresponding to the charge request value of zero value. In this way, the controller 30 is, for example, when the discharge of the capacitor 19 for causing the motor generator 12 to function as an electric motor to keep the load of the engine 11 constant is increased and the SOC of the capacitor 19 is low. By charging the capacitor 19 even when the rotation is stopped, over-discharging of the capacitor 19 is prevented.

Further, as shown by the discharge request line DL3 in FIG. 5, the controller 30 uses the capacitor 19 indicating the SOC (for example, 90%) corresponding to the discharge request value having a non-zero value, and the SOC (SOC) corresponding to the discharge request value having a value of zero. For example, discharge to 70%). In this way, the controller 30 causes, for example, the motor generator 12 to function as a generator in order to intentionally apply a load to the engine 11, or the motor generator 12 to make the load of the engine 11 constant. It is possible to prevent the SOC of the capacitor 19 from becoming excessively high even when the capacitor 19 is frequently charged by increasing the chance of functioning as the capacitor 19.

Further, when the capacitor 19 indicates an SOC (for example, 60% or more and 70% or less) in which both the charge request value and the discharge request value are zero, the controller 30 prevents the capacitor 19 from being charged and discharged.

With the above configuration, the controller 30 controls charging / discharging of the capacitor 19 based on the charging required value and the discharging required value corresponding to the current SOC of the capacitor 19. Therefore, the charging / discharging of the capacitor 19 can be controlled more appropriately.

Further, the controller 30 changes the charge request value and the discharge request value according to the state of the turning electric motor 21. Therefore, the charging / discharging of the capacitor 19 can be controlled more appropriately.

Next, with reference to FIG. 9, a process in which the controller 30 adjusts the contents of the SOC / required value correspondence table according to the capacitor temperature will be described. Note that FIG. 9 is a diagram showing another example of the SOC / required value correspondence table, and corresponds to FIG. Specifically, FIG. 9 is a graph showing the relationship between the SOC of the capacitor 19 and the discharge required value and the charge required value adopted when the turning motor 21 is in the power running state, and the horizontal axis is SOC [%. ], And the vertical axis corresponds to the output [kW].

The first discharge request line DLa shown by the broken line in FIG. 9 is the discharge request value adopted when the swivel motor 21 is in the power running state and the capacitor temperature is within the first temperature range (for example, 5 ° C. or higher). It shows the transition and corresponds to the discharge request line DL1 in FIG. The second discharge request line DLb shown by the broken line represents the transition of the discharge request value adopted when the capacitor temperature is within the second temperature range (for example, −5 ° C. or higher and lower than 5 ° C.). Similarly, the third discharge request line DLc shown by the broken line represents the transition of the discharge required value adopted when the capacitor temperature is within the third temperature range (for example, -15 ° C or more and less than -5 ° C), and is shown by the broken line. 4 The discharge request line DLd represents the transition of the discharge request value adopted when the capacitor temperature is within the fourth temperature range (for example, less than −15 ° C.).

The first charge request line CLa shown by the dotted line in FIG. 9 represents the transition of the charge request value adopted when the swivel motor 21 is in the power running state and the capacitor temperature is within the first temperature range. Corresponds to the charging request line CL1. The second charge request line CLb shown by the dotted line represents the transition of the charge request value adopted when the capacitor temperature is within the second temperature range. Similarly, the third charge request line CLc shown by the dotted line represents the transition of the charge request value adopted when the capacitor temperature is within the third temperature range, and the fourth charge request line CLd shown by the dotted line has the capacitor temperature of the third. 4 Shows the transition of the charge request value adopted when the temperature is within the range.

Further, the first discharge limit line ULa shown by the solid line in FIG. 9 represents the transition of the discharge limit value when the capacitor temperature is within the first temperature range. The discharge limit value means the maximum value of the electric power that the capacitor 19 can discharge, and is used to prevent over-discharge of the capacitor 19. Specifically, it is used to limit the discharge power of the capacitor 19 so that the terminal voltage of the capacitor 19 does not fall below a predetermined lower limit voltage. In FIG. 9, when the SOC is 30 [%], the discharge power of the capacitor 19 is limited by the value D10, and if the discharge power of the capacitor 19 exceeds the value D10, the terminal voltage may fall below the lower limit voltage. The second discharge limit line ULb shown by the solid line represents the transition of the discharge limit value when the capacitor temperature is within the second temperature range. Similarly, the third discharge limit line ULc shown by the solid line represents the transition of the discharge limit value when the capacitor temperature is within the third temperature range, and the fourth discharge limit line ULd shown by the solid line has the capacitor temperature of the fourth temperature. Shows the transition of the discharge limit value when it is within the range.

The first charge limit line BLa shown by the solid line in FIG. 9 represents the transition of the charge limit value when the capacitor temperature is within the first temperature range. The charge limit value means the maximum value of electric power that can be charged by the capacitor 19, and is used to prevent overcharging of the capacitor 19. Specifically, it is used when limiting the charging power of the capacitor 19 so that the terminal voltage of the capacitor 19 does not exceed a predetermined upper limit voltage. In FIG. 9, when the SOC is 55 [%], the charging power of the capacitor 19 is limited by the value C10, and if the charging power of the capacitor 19 exceeds the value C10, the terminal voltage may exceed the upper limit voltage. The second charge limit line BLb shown by the solid line represents the transition of the charge limit value when the capacitor temperature is within the second temperature range. Similarly, the third charge limit line BLc shown by the solid line represents the transition of the charge limit value when the capacitor temperature is within the third temperature range, and the fourth charge limit line BLd shown by the solid line shows that the capacitor temperature is the fourth temperature. Shows the transition of the charge limit value when it is within the range.

Next, the effect of changing the discharge request line to be adopted according to the capacitor temperature will be described.

In the example of FIG. 9, the value of the first discharge request line DLa becomes zero when the SOC is 60 [%] or less, and increases at a rate of change α until the SOC exceeds 60 [%] and reaches 100 [%]. .. Further, the value of the second discharge request line DLb becomes zero when the SOC is 48 [%] or less, and increases at a rate of change α until the SOC exceeds 48 [%] and reaches 100 [%]. Further, the value of the third discharge request line DLc becomes zero when the SOC is 40 [%] or less, and increases at a rate of change α until the SOC exceeds 40 [%] and reaches the discharge limit line, and the third discharge limit is reached. After reaching the level of the line ULc, it increases along the third discharge limit line ULc. Further, the value of the fourth discharge request line DLd becomes zero when the SOC is 25 [%] or less, and increases along the fourth discharge limit line ULd until the SOC exceeds 25 [%] and reaches 100 [%]. To do. The rate of change α of the first discharge request line DLa, the second discharge request line DLb, and the third discharge request line DLc with respect to SOC is equal in the region below the corresponding discharge limit line.

In this way, as the capacitor temperature decreases, the SOC (discharge start charge rate: discharge start SOC) when the discharge request value becomes larger than zero is lowered, so that the controller 30 can perform the regenerative operation of the regenerative motor 21. And the SOC when the regenerative operation is performed can be reduced. Specifically, when the capacitor temperature is within, for example, the first temperature range, the SOC of the capacitor 19 is 60 [%] to 60 [%] when the power running operation and the regenerative operation are performed by adopting the first discharge request line DLa. It changes in the range of 80 [%]. On the other hand, when the capacitor temperature is within, for example, the fourth temperature range, the SOC of the capacitor 19 is 25 [%] to 45 [%] to 45 [%] when the power running operation and the regenerative operation are performed by adopting the fourth discharge request line DLd. %] Changes in the range. Therefore, the controller 30 can prevent the charging power, which is the regenerative power generated by the turning electric motor 21 at the time of turning regeneration, from exceeding the charging limit line. Specifically, as shown in FIG. 9, when the SOC at the time of regenerative operation is 55 [%], if the capacitor temperature is within the first temperature range, the terminal voltage of the capacitor 19 is the upper limit voltage. It is possible to accept the charging power of the value C10 while preventing it from exceeding. However, if the capacitor temperature is within the second temperature range, the capacitor 19 cannot accept charging power larger than the value C11 in order to prevent the terminal voltage from exceeding the upper limit voltage. Further, if the capacitor temperature is within the third temperature range, the charging power larger than the value C12 cannot be accepted, and if the capacitor temperature is within the fourth temperature range, the charging power larger than the value C13 cannot be accepted. .. As described above, the charge power that the capacitor 19 can accept (acceptable charge power) becomes smaller as the capacitor temperature is lower. On the other hand, the acceptable charging power increases as the SOC decreases. From this relationship, the controller 30 lowers the discharge start SOC as the capacitor temperature decreases to reduce the SOC when the power running operation and the regenerative operation of the turning electric motor 21 are performed, so that the regenerative power at the time of turning regeneration ( It is possible to prevent the charging power) from exceeding the charging limit line.

Further, the internal resistance R of the capacitor 19 increases as the capacitor temperature decreases. Further, in the controller 30, the lower the capacitor temperature, the lower the discharge start SOC, so that the terminal voltage of the capacitor 19 at the time of charging / discharging is also lowered. Therefore, the discharge current that flows to obtain the same discharge power becomes large, and the charge current that flows to obtain the same charge power becomes large. Therefore, the calorific value of the capacitor 19 increases as the capacitor temperature decreases due to an increase in the internal resistance R and an increase in the charge / discharge current. As a result, warming up of the capacitor 19 can be promoted. The warm-up of the capacitor 19 is a process of forcibly raising the capacitor temperature by charging / discharging the capacitor 19 when the capacitor temperature is equal to or lower than a predetermined temperature. In this embodiment, if the excavator is not operated, the capacitor 19 is charged and discharged by using the motor generator 12 or the like even when the engine 11 is idling.

On the contrary, the internal resistance R of the capacitor 19 becomes smaller as the capacitor temperature is higher. Further, in the controller 30, the higher the capacitor temperature, the higher the discharge start SOC, so that the terminal voltage of the capacitor 19 at the time of charging and discharging is also increased. Therefore, the discharge current that flows to obtain the same discharge power becomes small, and the charge current that flows to obtain the same charge power becomes small. Therefore, the calorific value of the capacitor 19 decreases as the capacitor temperature increases as the internal resistance R decreases and the charge / discharge current decreases. As a result, heat loss can be reduced and the capacitor 19 can be used with high efficiency.

In FIG. 9, the discharge request line is set to draw a straight line, but it may be set to draw a curved line or a polygonal line.

Further, in FIG. 9, the capacitor temperature is within the first temperature range (for example, 5 ° C. or higher), the second temperature range (for example, −5 ° C. or higher and lower than 5 ° C.), and the third temperature range (for example, −15 ° C. or higher and −5 ° C. The discharge request line, discharge limit line, charge limit line, and charge limit line when the temperature is within the fourth temperature range (for example, less than -15 ° C) are shown, but the discharge request line and discharge are shown in other temperature increments. There may be a limit line, a charge request line, and a charge limit line.

Next, with reference to FIG. 10, regarding a process in which the controller 30 limits the turning speed during turning force running in order to deal with the acceptable charging power that decreases as the SOC of the capacitor 19 increases and as the capacitor temperature decreases. explain. Note that FIG. 10 is a diagram showing the relationship between the SOC of the capacitor 19 and the turning speed limit value. The horizontal axis corresponds to the SOC [%] and the vertical axis corresponds to the turning speed limit value [rpm].

Specifically, the acceptable charging power of the capacitor 19 is determined according to the SOC of the capacitor 19 and the capacitor temperature at the start of turning. For example, as shown in FIG. 9, if the capacitor temperature is within the second temperature range and the SOC is 55 [%], the acceptable charging power becomes the value C11 with reference to the second charging limit line BLb. Then, once the acceptable charging power is determined, the maximum feasible braking torque is determined within the range of the acceptable charging power, and the maximum turning speed (turning speed limit value) when the maximum braking torque is required is determined.

In this embodiment, the turning speed limit value Ncl has a charge limit value of Wcl, a maximum braking torque of Tmax, and a power corresponding to the assist limit value of Wa.

で表される。なお、ξ１、ξ２は効率を表す。また、旋回開始時は、例えば、旋回操作レバーの操作量が所定値を超えた時点、旋回速度が所定速度に達した時点等を意味する。また、コントローラ３０は、旋回開始時毎に旋回速度制限値を決定する。

It is represented by. In addition, ξ1 and ξ2 represent efficiency. Further, the start of turning means, for example, a time when the operating amount of the turning operation lever exceeds a predetermined value, a time when the turning speed reaches a predetermined speed, and the like. Further, the controller 30 determines the turning speed limit value every time the turning starts.

FIG. 10 shows the transition of the turning speed limit value determined as described above with respect to the SOC. Specifically, the turning speed limit line TL (20 ° C.) shown by the dotted line represents the transition of the turning speed limit value when the capacitor temperature is 20 ° C., and the turning speed limit line TL (-7 ° C.) shown by the dotted line is. , Represents the transition of the swirl speed limit value when the capacitor temperature is -7 ° C. The turning speed limit line TL (-10 ° C.) indicated by the dotted line represents the transition of the turning speed limit value when the capacitor temperature is −10 ° C., and the turning speed limit line TL (-20 ° C.) indicated by the dotted line is. It shows the transition of the turning speed limit value when the capacitor temperature is -20 ° C.

Further, in this embodiment, the turning speed is electrically or mechanically limited by the maximum value Rmax. Further, when the SOC at the start of turning is 55 [%] or less and the capacitor temperature is −7 ° C. or less, the turning speed limit value when the SOC is 55 [%] is adopted. This is to prevent the turning speed limit value from changing every time the turning operation is performed and the actual maximum turning speed from changing. Specifically, when the SOC at the start of turning is 55 [%] or less and the capacitor temperature is −10 ° C., the turning speed limit value is set to the value Rb. Further, when the SOC at the start of turning is 55 [%] or less and the capacitor temperature is −20 ° C., the turning speed limit value is set to the value Ra. If the SOC / required value correspondence table as shown in FIG. 9 is adopted, when the capacitor temperature is −7 ° C. or lower, the turning operation is usually performed in the range where the SOC is 55 [%] or less. Therefore, even if the turning speed limit value is changed along the turning speed limit line in the range where the SOC is larger than 55 [%], the actual maximum turning speed does not change every time the turning operation is performed. ..

In this way, the controller 30 limits the maximum swirl speed according to the capacitor temperature. Further, the controller 30 gradually releases the limitation of the maximum turning speed as the capacitor temperature rises.

Next, with reference to FIG. 11, a process in which the controller 30 limits the maximum turning torque during turning force running and the maximum pump output of the main pump 14 according to the limitation of the maximum turning speed will be described. The upper figure of FIG. 11 is a diagram showing the relationship between the turning speed limit value and the turning torque limit value. The horizontal axis corresponds to the turning speed limit value [rpm], and the vertical axis corresponds to the turning torque limit value [%]. Corresponds to. The lower figure of FIG. 11 is a diagram showing the relationship between the turning speed limit value and the pump current limit value. The horizontal axis corresponds to the turning speed limit value [rpm], and the vertical axis corresponds to the pump current limit value [mA]. Correspond.

For example, the controller 30 limits the turning speed limit value to the value Rb when the SOC at the start of turning is 55 [%] or less and the capacitor temperature is −10 ° C. In this case, the controller 30 refers to the corresponding table as shown in the upper figure of FIG. 11 and derives the value Sb as the turning torque limit value. Further, the controller 30 refers to the corresponding table as shown in the lower figure of FIG. 11 and derives the value Pb as the pump current limit value.

Similarly, the controller 30 limits the turning speed limit value to the value Ra (<Rb) when the SOC at the start of turning is 55 [%] or less and the capacitor temperature is −20 ° C. In this case, the controller 30 derives the value Sa (<Sb) as the turning torque limit value and the value Pa (<Pb) as the pump current limit value.

As with the turning speed limit value, the controller 30 determines the turning torque limit value and the pump current limit value each time the turning starts.

The limitation of the turning torque during the turning force running brings about the limitation of the acceleration of the upper swing body 3, and the limitation of the pump current brings about the limitation of the operating speed of the hydraulic actuator. Further, the relaxation of the limitation of the swing torque due to the subsequent rise in the capacitor temperature brings about the relaxation of the limitation of the acceleration of the upper swing body 3, and the relaxation of the limitation of the pump current brings about the relaxation of the limitation of the operating speed of the hydraulic actuator. Therefore, if the boom raising turn is performed when the turning speed limit value is limited to less than the maximum value Rmax, the rising speed of the boom 4 is also limited in accordance with the limitation of the turning speed. Further, as the turning speed limit value increases toward the maximum value Rmax due to the subsequent rise in the capacitor temperature, the turning speed limit is relaxed, and the rising speed limit of the boom 4 is also relaxed in accordance with the relaxation of the turning speed limit. Will be done. As a result, the controller 30 can provide the operator with the operating speed of the hydraulic actuator that matches the turning speed, and can prevent the operation feeling from being impaired.

When the maximum value Rmax is adopted as the turning speed limit value, the controller 30 derives the value Smax as the turning torque limit value and the value Pmax as the pump current limit value. That is, the controller 30 does not limit the maximum turning torque and the maximum pump output when the maximum turning speed is not limited.

With the above configuration, the controller 30 reduces the charge limit value and the discharge limit value and changes the discharge request value according to the decrease in the capacitor temperature. In this embodiment, the changes in the charge limit value and the discharge limit value with respect to the change in SOC are reduced, and the change in the discharge request value with respect to the change in SOC is reduced. Specifically, the respective limit values of the discharge limit line and the charge limit line are reduced as the capacitor temperature decreases. In addition, the slope of the discharge request line during turning force running is reduced as the capacitor temperature decreases. Therefore, the controller 30 can prevent overcharging and overdischarging of the capacitor 19 even when the turning electric motor 21 is driven in a state where the capacitor temperature is low. As a result, the controller 30 can drive the turning electric motor 21 without adversely affecting the capacitor 19 even before the warm-up of the capacitor 19 is completed.

Further, the controller 30 reduces the lower limit of the charge rate of the capacitor 19 which makes the discharge request value larger than zero as the capacitor temperature decreases. In this embodiment, the controller 30 reduces the discharge start SOC as the capacitor temperature decreases. Therefore, the controller 30 can control the charge / discharge of the capacitor 19 at the time of turning force running and at the time of turning regeneration so that the SOC of the capacitor 19 changes in a lower range as the capacitor temperature is lowered. As a result, the lower the capacitor temperature, the more the capacitor 19 can be charged and discharged under the condition that heat is more easily generated, and the warm-up of the capacitor 19 can be promoted. Further, as the capacitor temperature is lower, the SOC at the start of swirling regeneration is induced to be lower, so that it is possible to prevent the terminal voltage of the capacitor 19 from reaching the upper limit voltage during swirling regeneration, and it is possible to prevent overcharging of the capacitor 19.

In the above-described embodiment, the controller 30 adjusts the contents of the SOC / required value correspondence table according to the capacitor temperature when the turning electric motor 21 is in the power running operation state. However, the controller 30 does not adjust the contents of the SOC / required value correspondence table only when the turning motor 21 is in the power running state, but is also a capacitor when the turning motor 21 is in the regenerative operation state and the stopped state. The contents of the SOC / required value correspondence table may be adjusted according to the temperature.

With the above configuration, the controller 30 changes various settings related to charging / discharging according to the capacitor temperature, so that the excavator can be appropriately operated while preventing overcharging and overdischarging of the capacitor 19 even when the capacitor temperature is low. Can function.

However, the temperature characteristics of the capacitor 19 change as the capacitor 19 deteriorates. Therefore, the controller 30 may not be able to appropriately prevent overcharging and overdischarging of the deteriorated capacitor 19 when various settings related to charging / discharging are fixed so as to be optimum for the capacitor 19 when it is new, for example. .. As a result, the controller 30 may not be able to operate the excavator properly, which may reduce the workability of the excavator. In addition, the operator of the excavator may be forced to replace the deteriorated capacitor 19 with a new one at an early stage.

Therefore, the controller 30 executes a process of changing various settings related to charge / discharge according to the progress of deterioration of the capacitor 19 (hereinafter, referred to as “deterioration setting change process”). For example, the controller 30 grasps the degree of deterioration of the capacitor 19 and controls the operating temperature of the capacitor 19 according to the degree of deterioration. Specifically, the controller 30 raises the operating temperature of the capacitor 19 as the deterioration of the capacitor 19 progresses. This is to bring the internal resistance of the capacitor 19 close to the internal resistance of a new capacitor. Further, the internal resistance of the capacitor 19 increases as the capacitor temperature decreases, and increases as the deterioration of the capacitor 19 progresses. The operating temperature of the capacitor 19 means the temperature of the capacitor 19 during the operation of the excavator.

In this way, the controller 30 makes the deteriorated capacitor 19 function as if it were new, even when the capacitor 19 is deteriorated, for example, from the viewpoint of internal resistance. Then, even if the control concept suitable for a new product is used as it is, the excavator is made to function properly while preventing overcharging and overdischarging of the capacitor 19. The control concept means a general control content such as limiting charging when the capacitor temperature is lower than a predetermined temperature. In this case, the controller 30 can mitigate or eliminate the influence of the deterioration of the capacitor 19 on the control concept by automatically changing the setting contents of the predetermined temperature according to the progress of the deterioration of the capacitor 19. As a result, the controller 30 can prevent the workability of the excavator from being lowered even when the capacitor 19 is deteriorated.

In the following, various functional elements (deterioration degree acquisition unit 31, operating condition changing unit 32, and operation control unit 33) of the controller 30 that realize the above-mentioned deterioration setting change processing will be described in detail.

The deterioration degree acquisition unit 31 is a functional element for acquiring the deterioration degree of the power storage device. For example, the deterioration degree of the power storage device is based on the capacitance, internal resistance, deterioration state (SOH (State of Health)) of the power storage device, and the like. To get. The degree of deterioration of the power storage device is an index indicating the degree of deterioration of the power storage device. For example, once the degree of deterioration is determined, the correspondence between the temperature of the power storage device and the internal resistance is uniquely determined. In this embodiment, the deterioration degree acquisition unit 31 acquires the deterioration degree of the capacitor 19 based on the internal resistance of the capacitor 19.

Specifically, the deterioration degree acquisition unit 31 detects the capacitor temperature and derives the internal resistance of the capacitor 19 every time a predetermined time (for example, 10 hours) elapses. The capacitor temperature is detected by the temperature sensor M2. Further, the derivation of the internal resistance is based on the capacitor voltage value detected by the capacitor voltage detection unit 112 and the capacitor current value detected by the capacitor current detection unit 113. As described above, assuming that the open circuit voltage of the capacitor 19 is Vc [V], the internal resistance is R [Ω], and the charging current is Ic [A], the terminal voltage V2 [V] at the time of charging the capacitor 19 is V2. This is because it is represented by = Vc + R × Ic, and the internal resistance R is determined if the terminal voltage V2, the open circuit voltage Vc, and the charging current Ic are determined.

More specifically, when the deterioration degree acquisition unit 31 determines that a predetermined time has elapsed from the previous derivation of the internal resistance, the capacitor voltage detection unit 112 detects it in a state where the capacitor 19 is not charged or discharged. Let the capacitor voltage value (first voltage value) be the open circuit voltage Vc [V]. The first voltage value in this case corresponds to the terminal voltage V2 [V] of the capacitor 19 and corresponds to the open circuit voltage Vc [V] of the capacitor 19. This is because the charging current Ic [A] is 0 [A], so that the terminal voltage V2 [V] is equal to the open circuit voltage Vc [V].

After that, the deterioration degree acquisition unit 31 causes the motor generator 12 to function as a generator, and uses the power generated by the motor generator 12 to generate the capacitor 19 with a predetermined charging current Ic [A] (for example, 100 [A]). Charge.

The capacitor voltage value (second voltage value) in this case corresponds to the terminal voltage V2 [V] of the capacitor 19 represented by Vc + R × Ic. Therefore, the internal resistance R of the capacitor 19 is derived as (V2-Vc) / Ic, that is, a value obtained by subtracting the first voltage value from the second voltage value and dividing it by the value of the predetermined charging current Ic.

After that, the deterioration degree acquisition unit 31 derives the deterioration degree of the capacitor 19 from the combination of the capacitor temperature and the internal resistance R. In this embodiment, the degree of deterioration of the capacitor 19 is represented by the ratio of the current internal resistance value to the reference internal resistance value (deterioration rate), and the higher the degree of deterioration, the more the deterioration progresses. The reference internal resistance value represents the internal resistance value when the capacitor is new, and is preset in NVRAM or the like for each capacitor temperature.

Then, the deterioration degree acquisition unit 31 derives the ratio (deterioration rate) of the current internal resistance value to the reference internal resistance value as the deterioration degree. The deterioration rate is a value of "1" when the capacitor is new, and increases as the deterioration of the capacitor 19 progresses.

FIG. 12 is a diagram showing an example of the correspondence between the temperature of the capacitor 19 and the internal resistance, in which the temperature of the capacitor 19 is arranged on the horizontal axis and the internal resistance of the capacitor 19 is arranged on the vertical axis. Further, the correspondence relationship regarding the capacitor 19 when it is new is shown by a solid line, and the correspondence relationship when the capacitor 19 is deteriorated is shown by a broken line. Further, from FIG. 12, it can be obtained that the higher the temperature of the capacitor 19, the lower the internal resistance, regardless of the degree of deterioration of the capacitor 19. Further, it can be obtained that in the deteriorated capacitor 19, the internal resistance value derived at a certain temperature is higher than the internal resistance value (that is, the reference internal resistance value) when the capacitor is new at the same temperature. In other words, even if the capacitor 19 is deteriorated, the internal resistance value derived at a certain temperature corresponds to the internal resistance value (reference internal resistance value) of a new capacitor at a temperature lower than that temperature. Means. Therefore, it can be seen that if the temperature of the deteriorated capacitor 19 is controlled, the same internal resistance state as when the capacitor is new can be intentionally created. The control of the capacitor temperature will be described in detail below.

In FIG. 12, the point P1 shows the relationship between the current temperature T1 and the current internal resistance value R1, and the point P2 shows the relationship between the current temperature T1 and the reference internal resistance value R2 at the temperature T1. In this case, the deterioration rate D of the capacitor 19 is represented by the value D1 (= R1 / R2> 1) obtained by dividing the internal resistance value R1 by the reference internal resistance value R2, and the broken line indicates the point of the deterioration rate D1 at each capacitor temperature. Corresponds to the connected lines. Similarly, the solid line corresponds to the line connecting the deterioration rates D0 (= Rb / Rb = 1) at each capacitor temperature when the capacitor 19 is new. Therefore, the point P3, which is another point on the broken line, indicates that the internal resistance when the temperature of the capacitor 19 having the deterioration rate D1 reaches the temperature T2 (> T1) becomes the value R2. Similarly, the point P4, which is another point on the solid line, indicates that the internal resistance (reference internal resistance value) when the temperature of the capacitor 19 at the time of new product reaches the temperature T2 becomes the value R3.

Further, FIG. 12 shows that the internal resistance value when the temperature of the capacitor 19 having the deterioration rate D1 is the temperature T2 and the internal resistance value when the temperature of the capacitor 19 when the capacitor 19 is new is the same as the temperature T1. For example, the internal resistance value when the temperature of the capacitor 19 having a deterioration rate D1 is −14 ° C. is equal to the internal resistance value when the temperature of the capacitor 19 when the capacitor 19 is new is −20 ° C. Further, the internal resistance values when the temperature of the capacitor 19 having the deterioration rate D1 is -4 ° C, 9 ° C, and 29 ° C are the internal resistance values when the temperature of the capacitor 19 when new is -10 ° C, 0 ° C, and 20 ° C, respectively. Equal to the resistance value. This means that the internal resistance value of the deteriorated capacitor 19 in a specific temperature state corresponds to the internal resistance value of the new capacitor 19 in another specific temperature state on a one-to-one basis.

Therefore, the deterioration degree acquisition unit 31 uses the current temperature of the capacitor 19 detected by the temperature sensor M2, the current internal resistance value derived by the deterioration degree acquisition unit 31, and the reference map showing the correspondence as shown in FIG. Based on this, the internal resistance value when the capacitor 19 reaches an arbitrary temperature can be estimated. Specifically, the deterioration degree acquisition unit 31 multiplies the deterioration rate derived from the current capacitor temperature and the current internal resistance value by the reference internal resistance value of the target capacitor temperature to obtain the target capacitor temperature. The internal resistance value of the capacitor 19 can be estimated at that time.

In the above description, it is assumed that the deterioration rates are the same at any capacitor temperature. However, the present invention is not limited to this premise. For example, the correspondence between the capacitor temperature specified by the degree of deterioration and the internal resistance may be preset so that the deterioration rate at each capacitor temperature is different. In this case, the degree of deterioration of the capacitor 19 is specified by using an index other than the deterioration rate.

Further, the correspondence relationship between the capacitor temperature of the capacitor 19 and the internal resistance may be preset in association with the cumulative operating time of the excavator. In this case, the deterioration degree acquisition unit 31 acquires, for example, the cumulative operating time of the excavator managed by using NVRAM or the like as the deterioration degree, and specifies the correspondence relationship between the capacitor temperature of the capacitor 19 and the internal resistance from the deterioration degree. You may.

Further, the deterioration degree acquisition unit 31 is a capacitor of the capacitor 19 derived from the deterioration degree derived based on data on the past usage status of the capacitor 19 such as the temperature, charge / discharge current, and charge / discharge voltage transition of the capacitor 19 during excavator operation. The correspondence between the temperature and the internal resistance may be specified.

Further, in the above description, the deterioration degree acquisition unit 31 detects the capacitor temperature and derives the internal resistance of the capacitor 19 every time a predetermined time (for example, 10 hours) elapses. However, the deterioration degree acquisition unit 31 may derive the internal resistance of the capacitor 19 only when the predetermined time has elapsed and the capacitor temperature is equal to or higher than the predetermined temperature. This is because the lower the capacitor temperature, the larger the ratio of the fluctuation of the internal resistance to the fluctuation of the capacitor temperature, and it becomes difficult to derive the accurate internal resistance.

The operating condition changing unit 32 is a functional element that changes at least one operating condition of the power storage device and the device related to the power storage device according to the deterioration degree of the power storage device derived from the deterioration degree acquisition unit 31. In this embodiment, the operating condition changing unit 32 changes the operating conditions of the capacitor 19 and the equipment related to the capacitor 19 according to the deterioration degree of the capacitor 19 derived by the deterioration degree acquisition unit 31.

Specifically, the operating condition changing unit 32 increases or decreases the control temperature, which is the operating temperature of the capacitor 19, according to the degree of deterioration of the capacitor 19. For example, the operating condition changing unit 32 increases the control temperature, which is the operating temperature of the capacitor 19, as the degree of deterioration increases. Therefore, the operating condition changing unit 32 can charge and discharge the capacitor 19 with a relatively low internal resistance even when the capacitor 19 is deteriorated. As a result, the workability of the excavator can be improved as compared with the case where the capacitor 19 is charged and discharged while the internal resistance is relatively high.

For example, the operating condition changing unit 32 may change the operating conditions related to warming up the capacitor 19 by using the correspondence between the capacitor temperature and the internal resistance determined by the degree of deterioration of the capacitor 19. The warm-up of the capacitor 19 is a process of forcibly raising the capacitor temperature by charging / discharging the capacitor 19 with the motor generator 12 which is an example of the charging / discharging means when the capacitor temperature is equal to or lower than a predetermined temperature. Specifically, the operating condition changing unit 32 sets the warm-up start temperature (capacitor temperature when starting the warm-up of the capacitor 19) and the warm-up end temperature (warm-up of the capacitor 19) as the degree of deterioration of the capacitor 19 increases. The capacitor temperature at the time of termination may be increased. Further, the operating condition changing unit 32 changes the operation start temperature and the operation end temperature of the water pump, which is an example of the cooling means for cooling the capacitor 19, in accordance with the change of the warm-up start temperature and the warm-up end temperature. May be good. The warm-up start temperature and warm-up end temperature constitute a heating condition as an example of the operating conditions of the charging / discharging means, and the operating start temperature and the operating end temperature of the water pump are cooling as an example of the operating conditions of the cooling means. Configure the conditions. Then, the operating condition changing unit 32 may increase the control temperature, which is the operating temperature of the capacitor 19, by changing at least one of the heating condition and the cooling condition.

Further, even if the operating condition changing unit 32 changes the correspondence between the charge rate of the power storage device, the charge / discharge request value, and the charge / discharge limit value, which are set for each temperature of the power storage device according to the degree of deterioration of the power storage device. Good. Specifically, the operating condition changing unit 32 sets the SOC of the capacitor 19 and the charge / discharge request value and the charge / discharge limit value set for each temperature of the capacitor 19 as shown in FIG. 9 according to the degree of deterioration of the capacitor 19. You may change the correspondence of. The charge / discharge request value includes a charge request value and a discharge request value, and the charge / discharge limit value includes a charge limit value and a discharge limit value.

Further, the operating condition changing unit 32 may change the correspondence between the charging rate of the power storage device set for each temperature of the power storage device and the maximum turning speed of the turning electric motor according to the degree of deterioration of the power storage device. Specifically, the operating condition changing unit 32 determines the SOC of the capacitor 19 and the maximum turning speed of the turning electric motor 21 which are set for each temperature of the capacitor 19 as shown in FIG. 10 according to the degree of deterioration of the capacitor 19. The correspondence may be changed.

FIG. 13 shows a specific example of the operating conditions of the capacitor 19 and the equipment related to the capacitor 19 which are changed by the operating condition changing unit 32 according to the degree of deterioration of the capacitor 19.

Specifically, FIG. 13 shows that when the degree of deterioration of the capacitor 19 is at a “low” level (for example, 1.0 (when new) ≤ deterioration rate D <1.1), the warm-up start temperature and warm-up end temperature are set. They are set to -5 ° C and -1 ° C, respectively, and when the degree of deterioration is at the "medium" level (for example, 1.1 ≤ deterioration rate D <1.2), they are set to -2 ° C and 2 ° C, respectively, and deteriorate. It is shown that when the degree is a “high” level (for example, deterioration rate D ≧ 1.2), it is set to 1 ° C. and 5 ° C., respectively.

More specifically, the operating condition changing unit 32 refers to the reference map as shown in FIG. 12, and refers to the internal resistance value (that is, the reference internal resistance value) at the warm-up start temperature (-5 ° C.) of the capacitor 19 when it is new. ) Is derived. Then, the capacitor temperature that brings about the same internal resistance value as the reference internal resistance value is derived for the current deteriorated capacitor 19 and set as a new warm-up start temperature. The same applies to the warm-up end temperature. The warm-up start temperature and warm-up end temperature increase as the deterioration of the capacitor 19 progresses. That is, the higher the degree of deterioration of the capacitor 19, the higher the degree of deterioration. However, even if the warm-up start temperature and the warm-up end temperature become high, the warm-up time does not become excessively long. This is because as the deterioration of the capacitor 19 progresses, the internal resistance increases and the capacitor 19 tends to generate heat.

In this way, the operating condition changing unit 32 raises the warm-up start temperature and the warm-up end temperature as the degree of deterioration of the capacitor 19 increases. That is, the higher the degree of deterioration of the capacitor 19, the higher the temperature of the capacitor 19 is. Therefore, the operating condition changing unit 32 can charge and discharge the capacitor 19 with a relatively low internal resistance even when the capacitor 19 is deteriorated. As a result, the workability of the excavator can be improved as compared with the case where the capacitor 19 is charged and discharged while the internal resistance is relatively high.

Further, in FIG. 13, the turning speed limit start temperature is set to −7 ° C. when the degree of deterioration of the capacitor 19 is “low” level, and is set to -3 ° C. when the degree of deterioration is “medium” level. , Indicates that the temperature is set to 0 ° C. when the degree of deterioration is at the "high" level. The turning speed limit start temperature means the maximum value of the temperature at which the turning speed limit value is limited to less than the maximum value Rmax. For example, in FIG. 10, the swirl speed limit start temperature is −7 ° C., and if the capacitor temperature is higher than −7 ° C., as shown by the swirl speed limit line TL (-7 ° C.), when the SOC is 55% or less. The turning speed limit value is limited only to the maximum value Rmax, and is not limited to less than the maximum value Rmax.

In this way, the operating condition changing unit 32 raises the turning speed limit start temperature as the degree of deterioration of the capacitor 19 increases. That is, as the degree of deterioration of the capacitor 19 increases, the swirling speed limit value is limited to less than the maximum value Rmax at a higher capacitor temperature. This means that if the capacitor temperatures are the same, the maximum turning speed of the turning motor 21 decreases as the deterioration of the capacitor 19 progresses. That is, if the capacitor temperatures are the same, it means that the higher the degree of deterioration of the capacitor 19, the lower the maximum turning speed. Therefore, in the operating condition changing unit 32, even when the capacitor 19 is deteriorated, the charging power, which is the regenerative power generated by the turning electric motor 21 which is another example of the charging / discharging means at the time of turning regeneration, sets the charging limit line. It can be suppressed to exceed.

Further, the operating condition changing unit 32 changes the turning speed limit start temperature according to the degree of deterioration in the same manner as when changing the warm-up start temperature. Specifically, the internal resistance value (that is, the reference internal resistance value) at the turning speed limit start temperature (-7 ° C.) of the capacitor 19 when the capacitor 19 is new is derived by referring to the reference map as shown in FIG. Then, the capacitor temperature that brings about the same internal resistance value as the reference internal resistance value is derived for the current deteriorated capacitor 19 and set as a new turning speed limit start temperature.

Further, FIG. 13 shows that when the degree of deterioration of the capacitor 19 is at the “low” level, the first charge (discharge) request line / limit line (first charge request line CLa, first) when the capacitor temperature is 5 ° C. or higher. It shows that the discharge request line DLa, the first charge limit line BLa, and the first discharge limit line ULa) are adopted. In addition, the second charge (discharge) power request line / limit line is adopted when the capacitor temperature is -5 ° C or more and less than 5 ° C, and the third charge (release) is adopted when the capacitor temperature is -15 ° C or more and less than -5 ° C. ) The power request line / limit line is adopted, and the fourth charge (discharge) power request line / limit line is adopted when the capacitor temperature is less than -15 ° C. Further, in FIG. 13, when the degree of deterioration of the capacitor 19 is at the “medium” level, the first charge (discharge) power request line / limit line is adopted when the capacitor temperature is 10 ° C. or higher, and the capacitor temperature is −2 ° C. It is shown that the second charging (discharging) request line / limiting line is adopted when the temperature is lower than 10 ° C. In addition, the third charge (discharge) request line / limit line is adopted when the capacitor temperature is -13 ° C or higher and lower than -2 ° C, and the fourth charge (discharge) request is adopted when the capacitor temperature is lower than -13 ° C. Indicates that the line / limit line is adopted. Further, in FIG. 13, when the degree of deterioration of the capacitor 19 is at the “high” level, the first charge (discharge) power request line / limit line is adopted when the capacitor temperature is 14 ° C. or higher, and the capacitor temperature is 1 ° C. or higher. It is shown that the second charging (discharging) request line / limiting line is adopted when the temperature is lower than 14 ° C. In addition, the third charge (discharge) request line / limit line is adopted when the capacitor temperature is -12 ° C or more and less than 1 ° C, and the fourth charge (discharge) request line is adopted when the capacitor temperature is less than -12 ° C. / Indicates that the limit line is adopted.

In this way, the operating condition changing unit 32 raises the temperature range corresponding to each charge (discharge) request line / limit line as the degree of deterioration of the capacitor 19 increases. That is, as the degree of deterioration of the capacitor 19 increases, each of the charge limit value and the discharge limit value is set lower, and the charge request value and the discharge request value are set so that the discharge start SOC becomes smaller. To. This is because, if the capacitor temperature is the same, as the deterioration of the capacitor 19 progresses, the charge limit value and the discharge limit value become smaller, and the charge rate of the capacitor 19 when the charge request value and the discharge request value become zero. This means that (for example, the discharge start SOC) becomes smaller. That is, if the capacitor temperatures are the same, the charge limit value and the discharge limit value, and the charge rate of the capacitor 19 (for example, the discharge start SOC) when the charge request value and the discharge request value become zero are such that the capacitor 19 deteriorates. The higher it is, the smaller it is. Therefore, the operating condition changing unit 32 can suppress the occurrence of overcharging and overdischarging of the capacitor 19 even when the capacitor 19 is deteriorated.

Further, the operating condition changing unit 32 has a temperature range corresponding to each charge (discharge) request line / limit line according to the degree of deterioration in the same manner as when the warm-up start temperature and the turning speed limit start temperature are changed. To change. Specifically, referring to the reference map as shown in FIG. 12, the internal resistance values (that is, the reference) at the upper and lower limits of the temperature range corresponding to each charge (discharge) request line / limit line of the capacitor 19 when new. Internal resistance value) is derived. Then, the capacitor temperature that brings about the same internal resistance value as the reference internal resistance value is derived for the current deteriorated capacitor 19 and set as the upper limit and the lower limit of the new temperature range.

The degree of deterioration of the capacitor 19 is classified into three stages of "low", "medium", and "high" based on the deterioration rate, but it may be classified into two stages, and it is classified into four or more stages. May be good. Further, the value of the deterioration rate may be used as the degree of deterioration as it is.

The operation control unit 33 is a functional element that operates at least one of the power storage device and the equipment related to the power storage device according to the operation conditions changed by the operation condition changing unit 32. In this embodiment, the operating condition changing unit 32 operates the capacitor 19 and the equipment related to the capacitor 19 according to the changed operating condition.

For example, the operation control unit 33 starts charging / discharging the power storage device when the temperature of the power storage device becomes lower than the warm-up start temperature, and stores electricity when the temperature of the power storage device becomes equal to or higher than the warm-up end temperature. The charging / discharging of the device may be stopped. Specifically, the operation control unit 33 starts charging / discharging of the capacitor 19 by the motor generator 12 when the capacitor temperature becomes lower than the warm-up start temperature, and the capacitor temperature becomes equal to or higher than the warm-up end temperature. In that case, the charging / discharging of the capacitor 19 by the motor generator 12 may be stopped.

Further, the operation control unit 33 may limit the turning speed of the turning electric motor to or less than the maximum turning speed (turning speed limit value) determined by the temperature and the charging rate of the power storage device. Specifically, the operation control unit 33 may limit the turning speed of the turning electric motor 21 to or less than the maximum turning speed (turning speed limit value) determined by the capacitor temperature and the SOC. In this case, as shown in FIG. 11, the operation control unit 33 may limit the turning torque (turning acceleration) by using the turning torque limit value corresponding to the maximum turning speed (turning speed limit value), and the maximum turning The pump current (discharge amount of the main pump 14) may be limited by using the pump current limit value corresponding to the speed (swivel speed limit value).

Further, the operation control unit 33 may control the charge / discharge of the power storage device according to the charge / discharge request value and the charge / discharge limit value determined by the temperature and charge rate of the power storage device. Specifically, as shown in FIG. 9, the operation control unit 33 controls the charge / discharge of the capacitor 19 according to the charge request value, the discharge request value, the charge limit value, and the discharge limit value determined by the capacitor temperature and the SOC. You may.

The operation control unit 33 uses the detection value of the temperature sensor M2 as the capacitor temperature. Further, the SOC is calculated based on the capacitor voltage value detected by the capacitor voltage detection unit 112 and the capacitor current value detected by the capacitor current detection unit 113.

With the above configuration, when the capacitor 19 deteriorates, the controller 30 controls so that the capacitor temperature during the operation of the excavator becomes relatively higher than that before the deterioration. Specifically, the controller 30 changes the operating conditions of at least one of the capacitor 19 and the equipment related to the capacitor 19 (motor generator 12, turning electric motor 21, etc.) according to the degree of deterioration of the capacitor 19. Then, at least one of the capacitor 19 and the device related to the capacitor 19 is operated according to the changed operating conditions. Therefore, the controller 30 can operate the deteriorated capacitor 19 under the same conditions as the capacitor 19 when it is new, for example, from the viewpoint of the internal resistance value. Therefore, the excavator on which the controller 30 is mounted can prevent a decrease in workability even when the capacitor 19 is deteriorated.

Further, even if the deterioration of the capacitor 19 is advanced, the workability of the excavator can be prevented from being lowered, so that the replacement timing of the capacitor 19 can be delayed.

Further, the controller 30 operates at least one of the capacitor 19 and the equipment related to the capacitor 19 according to the operating conditions changed according to the degree of deterioration of the capacitor 19. Therefore, the capacitor 19 can be appropriately operated according to the degree of deterioration of the capacitor 19, and overcharging, overdischarging, and the like can be prevented.

Although the preferred examples of the present invention have been described in detail above, the present invention is not limited to the above-mentioned examples, and various modifications and substitutions are made to the above-mentioned examples without departing from the scope of the present invention. Can be added.

For example, in the above-described embodiment, the deterioration rate is represented by the ratio of the current internal resistance value to the reference internal resistance value (deterioration rate). However, the present invention is not limited to this configuration. For example, if the capacitance is derived instead of the internal resistance value, the degradation rate may be expressed as the ratio of the current capacitance to the reference capacitance. In this case, the reference capacitance represents the capacitance when the capacitor is new, and is preset in NVRAM or the like for each capacitor temperature.

1 ... Lower traveling body 1A, 1B ... Hydraulic motor 2 ... Swivel mechanism 3 ... Upper swivel body 4 ... Boom 5 ... Arm 6 ... Bucket 7 ... Boom cylinder 8・ ・ ・ Arm cylinder 9 ・ ・ ・ Bucket cylinder 10 ・ ・ ・ Cabin 11 ・ ・ ・
・ Engine 12 ・ ・ ・ Motor generator 13 ・ ・ ・ Transmission 14 ・ ・ ・ Main pump 15
・ ・ ・ Pilot pump 16 ・ ・ ・ High-pressure flood control line 17 ・ ・ ・ Control valve
18, 20 ... Inverter 19 ... Capacitor 20 ... Capacitor 21 ...
・ Swivel motor 22 ・ ・ ・ Resolver 23 ・ ・ ・ Mechanical brake 24 ・ ・ ・ Swivel transmission 25 ・ ・ ・ Pilot line 26 ・ ・ ・ Operating device 26A, 26B ・ ・ ・ Lever 26C ・ ・ ・ Pedal 27 ・ ・ ・Hydraulic line 28 ・ ・ ・ Hydraulic line 29 ・ ・ ・ Pressure sensor 30 ・ ・ ・ Controller 31 ・ ・ ・ Deterioration degree acquisition unit 32 ・ ・ ・ Operating condition change unit 33 ・ ・ ・ Operation control unit 100 ・ ・ ・ Buck-boost converter 110・ ・ ・ DC bus 1
11 ... DC bus voltage detector 112 ... Capacitor voltage detector 113 ... Capacitor current detector 120 ... Storage system

Claims (10)

A construction machine including a power storage device, an electric motor driven by the electric power of the power storage device, and a control device.
When the power storage device deteriorates, the control device raises the temperature setting value of the power storage device relatively higher than that before the deterioration so that the temperature of the power storage device becomes higher during the operation of the construction machine. Set to
When the power storage device deteriorates, the power storage device operates under the set value that is relatively higher than that before the deterioration.
Construction machinery. The temperature setting value of the power storage device includes an upper limit and / or a lower limit of the temperature range of the power storage device.
The construction machine according to claim 1. A cooling means for cooling the power storage device is provided.
When the power storage device deteriorates, the control device changes the operating conditions of the cooling means during the operation of the construction machine.
The construction machine according to claim 1 or 2. The control device changes the temperature conditions related to the electric motor when the power storage device deteriorates.
The construction machine according to claim 1 or 2. In the control device, the higher the degree of deterioration of the power storage device, the higher the temperature set value of the power storage device.
The construction machine according to any one of claims 1 to 4. The control device increases the rotation speed limit start temperature, which is the maximum value of the temperature at which the rotation speed value of the electric motor is limited to less than a predetermined value, as the degree of deterioration of the power storage device increases.
The construction machine according to claim 4. The control device increases the temperature setting value related to the charge limit value or the discharge limit value of the power storage device as the degree of deterioration of the power storage device increases.
The construction machine according to claim 1 or 2. A construction machine including a power storage device, an electric motor driven by the electric power of the power storage device, and a control device.
When the power storage device deteriorates, the control device limits the rotation speed, which is the maximum value of the temperature at which the value of the rotation speed of the electric motor is limited to less than a predetermined value as the degree of deterioration of the power storage device increases. Raise the starting temperature,
Construction machinery. The degree of deterioration is calculated based on at least one of the capacitance of the power storage device, internal resistance, SOH, cumulative operating time of the construction machine, temperature of the power storage device, charge / discharge current, and charge / discharge voltage. Be done,
The construction machine according to any one of claims 5 to 8. A first map showing the relationship between the temperature and the internal resistance of the power storage device before deterioration and a second map showing the relationship between the temperature and the internal resistance of the power storage device after deterioration are provided.
The set value of the temperature in the power storage device after deterioration is
Any one of claims 1 to 9 derived based on the set value of the temperature in the power storage device before deterioration, the internal resistance derived based on the first map, and the second map. Construction machinery described in the section.

Images