JP5037555B2 - Hybrid construction machine - Google Patents

Description

  The present invention relates to a hybrid construction machine.

  Conventionally, a hybrid construction machine in which a part of the drive mechanism is motorized has been proposed. Such a hybrid construction machine includes a hydraulic pump for hydraulically driving movable parts such as a boom, an arm, and a bucket, and an AC motor is used as an internal combustion engine engine (engine) for driving the hydraulic pump. (Motor generator) is connected to assist the driving force of the engine, and electric power obtained by power generation is stored in a storage battery (battery).

  In addition, construction machines often include a work element such as an upper turning body. In such a case, the hybrid construction machine may include a working electric motor for assisting the hydraulic motor in addition to the hydraulic motor for driving the working element. For example, when the upper swing body is turned, the drive of the hydraulic motor is assisted by the AC motor during acceleration turning, and the regenerative operation is performed in the AC motor during deceleration turning, and the generated power is stored in the battery.

  As an example of such a hybrid construction machine, there is a hydraulic drive device described in Patent Document 1. In this apparatus, an electric motor that also serves as a generator is attached to a hydraulic pump, and the electric motor performs a power generation operation and an assist operation by switching control of a controller. In addition, a revolving pump motor that drives the revolving structure is provided, and rotational kinetic energy is regenerated during braking of the revolving system.

JP-A-10-103112

  In the hybrid construction machine described above, when an abnormality occurs in the engine that drives the hydraulic pump, if the operation is continued as it is, the load becomes excessive with respect to the driving capability of the engine, and the engine may be stopped naturally. In addition, when an abnormality occurs in a battery that supplies power to a motor generator or the like, if the operation is continued as it is, the charging rate of the battery may be excessively decreased, and it may be difficult to continue the operation.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a hybrid construction machine that can continue operation for a longer time even when an abnormality occurs in an engine or a battery. To do.

  In order to solve the above-described problems, a hybrid type construction machine according to the present invention is connected to an internal combustion engine engine and the internal combustion engine engine, and generates power using the driving force of the internal combustion engine motor, A motor generator for assisting the driving force of the internal combustion engine engine; an inverter circuit having one end connected to an electrical terminal of the motor generator; and a storage battery connected to the other end of the inverter circuit via a DC voltage converter; A storage system abnormality detection unit that detects an abnormality of the storage system including the DC voltage converter and the storage battery, and an abnormality detection unit of at least one of an engine system abnormality detection unit that detects an abnormality of the internal combustion engine engine, an inverter circuit, and A control unit that adjusts output dependency on each of the power storage system and the internal combustion engine motor by controlling the DC voltage converter, and the control unit includes a power storage system abnormality detection unit If an abnormality in the power storage system is detected, the output dependency on the internal combustion engine is relatively increased compared to the output dependency on the power storage system, and an abnormality in the internal combustion engine is detected in the engine system abnormality detection unit. Is detected, the output dependency on the power storage system is relatively increased as compared with the output dependency on the internal combustion engine engine.

  Further, when the hybrid construction machine includes a power storage system abnormality detection unit, the control unit lowers the output limit value of the storage battery when a storage system abnormality is detected in the power storage system abnormality detection unit. It is good.

  Further, when the hybrid type construction machine includes a power storage system abnormality detection unit, the control unit increases the output upper limit value of the internal combustion engine engine when a power storage system abnormality is detected in the power storage system abnormality detection unit. This may be a feature.

  Further, in the case where the hybrid construction machine includes an engine system abnormality detection unit, when the control unit detects an abnormality of the internal combustion engine motor in the engine system abnormality detection unit, the output upper limit value of the internal combustion engine motor It may be characterized by lowering.

  In addition, when the hybrid construction machine includes an engine system abnormality detection unit, the control unit increases the output limit value of the storage battery when an abnormality of the internal combustion engine engine is detected in the engine system abnormality detection unit. May be a feature.

  According to the hybrid type construction machine of the present invention, even if an abnormality occurs in the engine or the battery, the operation can be continued for a longer time.

1 is a perspective view showing an external appearance of a power shovel 1 as an example of a hybrid type construction machine according to the present invention. It is a block diagram which shows internal structures, such as an electric system and a hydraulic system, of the power shovel. It is a figure which shows the internal structure of the electrical storage means 120 in FIG. It is a block diagram which shows the function which the controller 30 has. 3 is a flowchart of processing performed in a controller 30. It is a detailed flowchart regarding step S4 of FIG. It is a detailed flowchart regarding step S5 of FIG. It is a detailed flowchart regarding step S6 of FIG. It is a figure which shows the relationship between a battery charge rate (SOC) and a battery output. FIG. 6 is a diagram schematically showing a process for increasing the output dependency relative to the engine 11 in comparison with the power storage system when an abnormality is detected in the power storage system including the battery 19 and the buck-boost converter 100. (A) A map or conversion table in the block 31 of the controller 30 is shown. (B) A map or conversion table in the block 33 of the controller 30 is shown. 4 is a graph showing an example of changes in engine output P _Eng and battery output P _Bat before and after time t ₁ when an abnormality in the power storage system (overheating of the battery 19) occurs in the power shovel 1; FIG. 6 is a diagram schematically showing a process for increasing the output dependency on the power storage system relative to the engine when an abnormality is detected in the engine. (A) A map or conversion table in the block 31 of the controller 30 is shown. (B) A map or conversion table in the block 33 of the controller 30 is shown. In the power shovel 1, the abnormality of the engine 11 before and after the time t ₁ (the incomplete combustion of the engine 11, the abnormality of the boost pressure of the turbocharger 41, or the failure of the water temperature sensor, etc.) has occurred, the engine output P _Eng and the battery It is a graph which shows an example of the mode of change of output P _Bat .

  Embodiments of a hybrid construction machine according to the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 1, a power shovel 1 according to this embodiment includes a traveling mechanism 2 including an endless track, and a revolving body 4 that is rotatably mounted on an upper portion of the traveling mechanism 2 via a revolving mechanism 3. I have. The swing body 4 is attached with a boom 5, an arm 6 linked to the tip of the boom 5, and a bucket 7 linked to the tip of the arm 6. The boom 5, the arm 6, and the bucket 7 are hydraulically driven by a boom cylinder 8, an arm cylinder 9, and a bucket cylinder 10, respectively. Further, the revolving body 4 is provided with a power source such as a driver's cab 4a for accommodating an operator who operates the position and angle of the bucket 7, and an engine (internal combustion engine engine) 11 for generating hydraulic pressure. Yes. The engine 11 is composed of, for example, a diesel engine.

  FIG. 2 is a block diagram showing an internal configuration such as an electric system and a hydraulic system of the power shovel 1 of the present embodiment. In FIG. 2, the mechanical power transmission system is indicated by a double line, the hydraulic system is indicated by a thick solid line, the steering system is indicated by a broken line, and the electrical system is indicated by a thin solid line. FIG. 3 is a diagram showing an internal configuration of the power storage means 120 in FIG.

  As shown in FIG. 2, the excavator 1 includes a supercharger 41 and an engine control unit (ECU) 42. The supercharger 41 is a device for supplying compressed air to the engine 11. The supercharger 41 rotates the turbine at high speed using the pressure of the exhaust gas discharged from the engine 11, rotates the compressor directly connected to the turbine, compresses the intake air, and supplies the compressed air to the engine 11. Thereby, the intake air amount of the engine 11 is increased.

  The ECU 42 is a unit for controlling the operation of the engine 11 (such as fuel injection timing of the engine 11). Further, the ECU 42 of the present embodiment constitutes an engine system abnormality detection unit for detecting an abnormality of the engine 11. That is, the ECU 42 detects an abnormal signal related to incomplete combustion provided from an injection nozzle sensor 43 attached to the engine 11, an abnormal signal related to an abnormal boost pressure of the supercharger 41, and the temperature of cooling water that cools the engine 11. An abnormality signal related to a failure of the water temperature sensor or the like is detected to the controller 30 described later.

  The power shovel 1 includes a motor generator 12 and a speed reducer 13, and the rotation shafts of the engine 11 and the motor generator 12 are connected to each other by being connected to the input shaft of the speed reducer 13. When the load on the engine 11 is large, the motor generator 12 assists the driving force of the engine 11 by driving the engine 11 as a work element, and the driving force of the motor generator 12 is the output shaft of the speed reducer 13. And then transmitted to the main pump 14. On the other hand, when the load on the engine 11 is small, the driving force of the engine 11 is transmitted to the motor generator 12 via the speed reducer 13, so that the motor generator 12 generates power. The motor generator 12 is configured by, for example, an IPM (Interior Permanent Magnetic) motor in which a magnet is embedded in the rotor. Switching between driving and power generation of the motor generator 12 is performed according to the load of the engine 11 and the like by the controller 30 that performs drive control of the electric system in the power shovel 1.

  A main pump 14 and a pilot pump 15 are connected to the output shaft of the speed reducer 13, and a control valve 17 is connected to the main pump 14 via a high pressure hydraulic line 16. The control valve 17 is a device that controls the hydraulic system in the power shovel 1. In addition to the hydraulic motors 2a and 2b for driving the traveling mechanism 2 shown in FIG. 1, the boom cylinder 8, the arm cylinder 9 and the bucket cylinder 10 are connected to the control valve 17 via a high pressure hydraulic line. The control valve 17 controls the hydraulic pressure supplied to them according to the operation input of the driver.

  The output terminal of the inverter circuit 18 is connected to the electrical terminal of the motor generator 12. The power storage means 120 is connected to the input terminal of the inverter circuit 18. As shown in FIG. 3, the power storage unit 120 includes a DC bus 110 that is a DC bus, a step-up / down converter (DC voltage converter) 100, and a battery 19. That is, the input terminal of the inverter circuit 18 is connected to the input terminal of the step-up / down converter 100 via the DC bus 110. A battery 19 as a storage battery is connected to the output terminal of the step-up / down converter 100.

  The inverter circuit 18 controls the operation of the motor generator 12 based on a command from the controller 30. That is, when the inverter circuit 18 power-operates the motor generator 12, necessary power is supplied from the battery 19 and the buck-boost converter 100 to the motor generator 12 via the DC bus 110. Further, when the motor generator 12 is regeneratively operated, the battery 19 is charged with the electric power generated by the motor generator 12 through the DC bus 110 and the step-up / down converter 100. The switching control between the step-up / step-down operation of the step-up / step-down converter 100 is performed by the controller 30 based on the DC bus voltage value, the battery voltage value, and the battery current value. As a result, the DC bus 110 can be maintained in a state of being stored at a predetermined constant voltage value.

  Note that the buck-boost converter 100 of this embodiment has a switching control system, and as shown in FIG. 3, transistors 100a and 100b connected in series with each other, their connection point, and the positive terminal of the battery 19 , A diode 100c connected in parallel in the reverse direction to the transistor 100a, and a diode 100d connected in parallel in the reverse direction to the transistor 100b. The transistors 100a and 100b are configured by, for example, an IGBT (Insulated Gate Bipolar Transistor). When DC power is supplied from the battery 19 to the DC bus 110, a PWM voltage is applied to the gate of the transistor 100a according to a command from the controller 30. Then, the induced electromotive force generated in the reactor 101 when the transistor 100a is turned on / off is transmitted through the diode 100d, and this power is smoothed by the capacitor 110a of the DC bus 110. Further, when supplying DC power from the DC bus 110 to the battery 19, a PWM voltage is applied to the gate of the transistor 100 b according to a command from the controller 30, and the current output from the transistor 100 b is smoothed by the reactor 101. Is done.

  The power storage system including the step-up / down converter 100 and the battery 19 is provided with a power storage system abnormality detection unit for detecting the abnormality of the power storage system. For example, in the present embodiment, a temperature sensor 44 for detecting the temperature of the battery 19 is attached to the battery 19 as a power storage system abnormality detection unit. The temperature sensor 44 provides a signal related to the temperature of the battery 19 (battery temperature signal) to the controller 30.

  Referring again to FIG. 2, the inverter circuit 20 is connected to the power storage means 120. One end of the inverter circuit 20 is connected to a turning motor (AC motor) 21 as a working motor, and the other end of the inverter circuit 20 is connected to the DC bus 110 of the power storage means 120. The turning electric motor 21 is a power source of the turning mechanism 3 for turning the turning body 4. A resolver 22, a mechanical brake 23, and a turning speed reducer 24 are connected to the rotating shaft 21 </ b> A of the turning electric motor 21.

  When the turning electric motor 21 performs a power running operation, the rotational force of the rotational driving force of the turning electric motor 21 is amplified by the turning speed reducer 24, and the turning body 4 is subjected to acceleration / deceleration control to perform rotational motion. Further, due to the inertial rotation of the swing body 4, the rotation speed is increased by the swing speed reducer 24 and transmitted to the swing electric motor 21 to generate regenerative power. The electric motor 21 for turning is AC driven by the inverter circuit 20 by a PWM (Pulse Width Modulation) control signal. As the turning electric motor 21, for example, a magnet-embedded IPM motor is suitable.

  The resolver 22 is a sensor that detects the rotation position and rotation angle of the rotation shaft 21A of the turning electric motor 21, and mechanically connects to the turning electric motor 21 to detect the rotation angle and rotation direction of the rotation shaft 21A. When the resolver 22 detects the rotation angle of the rotation shaft 21A, the rotation angle and the rotation direction of the turning mechanism 3 are derived. The mechanical brake 23 is a braking device that generates a mechanical braking force, and mechanically stops the rotating shaft 21 </ b> A of the turning electric motor 21 according to a command from the controller 30. The turning speed reducer 24 is a speed reducer that reduces the rotational speed of the rotating shaft 21 </ b> A of the turning electric motor 21 and mechanically transmits it to the turning mechanism 3.

  Since the motor generator 12 and the turning motor 21 are connected to the DC bus 110 via the inverter circuits 18 and 20, the electric power generated by the motor generator 12 is directly supplied to the turning motor 21. In some cases, electric power regenerated by the turning electric motor 21 may be supplied to the motor generator 12.

  An operation device 26 is connected to the pilot pump 15 via a pilot line 25. The operating device 26 is an operating device for operating the turning electric motor 21, the traveling mechanism 2, the boom 5, the arm 6, and the bucket 7, and is operated by an operator. A control valve 17 is connected to the operating device 26 via a hydraulic line 27, and a pressure sensor 29 is connected via a hydraulic line 28. The operating device 26 converts the hydraulic pressure (primary hydraulic pressure) supplied through the pilot line 25 into a hydraulic pressure (secondary hydraulic pressure) corresponding to the operation amount of the operator and outputs the hydraulic pressure. The secondary hydraulic pressure output from the operating device 26 is supplied to the control valve 17 through the hydraulic line 27 and detected by the pressure sensor 29. Here, although the turning electric motor 21 is cited as the working electric motor, the traveling mechanism 2 may be electrically driven as the working electric motor.

  When an operation for turning the turning mechanism 3 is input to the operating device 26, the pressure sensor 29 detects this operation amount as a change in the oil pressure in the hydraulic line 28. The pressure sensor 29 outputs an electrical signal indicating the hydraulic pressure in the hydraulic line 28. This electric signal is input to the controller 30 and used for driving control of the turning electric motor 21.

  The controller 30 constitutes a control unit in the present embodiment. The controller 30 is configured by an arithmetic processing unit including a CPU and an internal memory, and is realized by the CPU executing a drive control program stored in the internal memory. The power source of the controller 30 is a battery (for example, a 24V on-vehicle battery) different from the battery 19. The controller 30 converts a signal representing an operation amount for turning the turning mechanism 3 among signals inputted from the pressure sensor 29 into a speed command, and performs drive control of the turning electric motor 21. Further, the controller 30 performs operation control (switching between assist operation and power generation operation) of the motor generator 12 and charge / discharge control of the battery 19 by controlling driving of the step-up / down converter 100.

  Here, among the functions of the controller 30 in the present embodiment, the function of adjusting the output dependency on each of the power storage system including the battery 19 and the buck-boost converter 100 and the engine 11 will be described. FIG. 4 is a block diagram illustrating functions of the controller 30. As shown in FIG. 4, the controller 30 of the present embodiment includes an output condition calculation unit 39 that calculates upper and lower limits of output corresponding to the output dependency on the engine 11 and the battery 19, and a power distribution unit 38. . The output condition calculation unit 39 includes functional blocks 31 to 37.

First, the actual engine speed N _act which is a signal indicating the actual engine speed of the engine 11 is input to the block 31 of the output condition calculation unit 39. Block 31 determines the upper limit value P _EngMax and the lower limit value P _EngMin of the engine output torque based on the actual engine rotational speed N _act, to provide these values to the power distribution unit 38. The block 31 has a map or conversion table indicating the upper limit value and the lower limit value in the relationship between the rotational speed of the engine 11 and the output torque, and the upper limit value P of the engine output torque based on this map or conversion table. _EngMax and lower limit value P _EngMin are determined. The map or conversion table is stored in advance in the memory of the controller 30. Note that the upper limit value P _EngMax and the lower limit value P _EngMin may be obtained by substituting the actual engine speed N _act into an expression representing the upper limit value and the lower limit value without using a map or a conversion table.

A signal indicating the hydraulic load request output P _HydReq and a signal indicating the electric load request output P _ElcReq are input to the power distribution unit 38. The hydraulic load request output P _HydReq is a variable indicating the power required by the hydraulic load (components driven by hydraulic pressure, such as the boom cylinder 8, the arm cylinder 9, the bucket cylinder 10, and the hydraulic motors 2a and 2b). For example, this corresponds to the operation amount of the operation lever when the driver operates the hydraulic load. The electric load required output P _ElcReq is a variable indicating electric power required by an electric load (a component driven by electric power such as an electric motor or an electric actuator, such as the turning electric motor 21). This corresponds to the amount of operation of the operating lever when operating.

The battery voltage V _act is input to the block 32 of the output condition calculation unit 39. The battery voltage V _act is a variable indicating the output voltage of the battery 19. In the case of a capacitor-type storage battery, the amount of charge is proportional to the square of the voltage across the terminals of the capacitor, so the charge rate of the battery 19 can be known through the battery voltage V _act . Block 32 determines the current charge rate SOC _act of battery 19 based on battery voltage V _act and provides it to blocks 33, 34 and 37.

The block 33 of the output condition calculation unit 39 stores a map or conversion table representing the output [kW] for charging with the maximum current and the output [kW] for discharging with the maximum current according to the charging rate SOC. Based on this map or conversion table and the charge rate SOC _act of the battery 19 provided from the block 32, the block 33 is a battery output upper limit P _BatMax11 that is the maximum discharge amount and a battery output lower limit that is the maximum charge amount. _{Determine the} value P _BatMin11 . The block 33 provides the battery output upper limit value P _BatMax11 to the block 35 and the battery output lower limit value P _BatMin11 to the block 36.

For example, the map of the block 33 represents electric power (charge / discharge maximum current × capacitor voltage) determined when a maximum charge / discharge current limited by the capacity of the converter and the capacitor flows at a certain charge rate SOC. Since the charge rate SOC is proportional to the square of the charge / discharge voltage (capacitor voltage), the maximum charge power and the maximum discharge power draw a parabola with respect to the charge rate SOC. The block 33 refers to this map or conversion table, and the maximum charge power (battery output upper limit value P _BatMax11 ) and the maximum discharge power (battery output lower limit value) allowed under a constant current at the current charge rate SOC _act . The value P _BatMin11 ) is determined.

The block 34 includes a map representing an output [kW] for discharging the energy up to the SOC lower limit value for a predetermined time and an output [kW] for charging the energy up to the SOC upper limit value for a predetermined time, or Stores conversion tables. Based on this map or conversion table and the charge rate SOC _act of the battery 19 provided from the block 32, the block 34 determines the battery output upper limit P _BatMax12 that is the maximum discharge amount and the battery output lower limit that is the maximum charge amount. _{Determine the} value P _BatMin12 . The block 34 provides the battery output upper limit value P _BatMax12 to the block 35 and the battery output lower limit value P _BatMin12 to the block 36.

  For example, the map shown in block 34 represents the appropriate charge / discharge power at a certain charge rate SOC. In the map shown in block 34, the lower limit value is a charging rate SOC set to allow a margin so that the charging rate does not become zero. If the charging rate SOC decreases to zero or close to zero, it becomes impossible to immediately discharge when a discharge request is made. Therefore, it is desirable to maintain a state of being charged to some extent. Therefore, a lower limit value (for example, 30%) is provided for the charging rate SOC, and control is performed so as not to discharge when the charging rate SOC is equal to or lower than the lower limit value. Therefore, the maximum discharge power (the maximum power that can be discharged) is zero (that is, not discharged) at the lower limit value of the charge rate SOC, and there is a margin in the dischargeable power as the charge rate SOC increases. It is getting bigger. In the map of the block 34 in the figure, the maximum discharge power increases linearly from the upper limit value of the charging rate SOC. However, the maximum discharge power is not limited to a linear increase, and may be increased by drawing a parabola. You may set so that it may increase with a pattern.

  On the other hand, when regenerative power is generated from an electrical load when the charge rate SOC is 100%, for example, the regenerative power cannot be immediately absorbed by the battery 19, so the upper limit value is set so that the charge rate SOC does not reach 100%. (For example, 90%) is provided, and control is performed so that charging is not performed when the charging rate SOC is equal to or higher than the upper limit value. Therefore, the maximum charge power (maximum chargeable power) is zero (that is, not charged) in the upper limit value of the charge rate SOC, and there is a margin in the chargeable power as the charge rate SOC decreases. Enlarge. In the map of the block 34 in the figure, the maximum charging power increases linearly from the upper limit value of the charging rate SOC. However, the maximum charging power is not limited to a linear increase, and may be increased by drawing a parabola. You may set so that it may increase with a pattern.

As described above, the block 34 refers to this map or conversion table, and allows the maximum discharge power (battery output upper limit value P _BatMax12 ) and the maximum charge power (battery output lower limit value P _BatMin12 ) allowed for the current charge rate SOC _act . Ask for.

Block 35, provides the battery output upper limit value P _BatMax11 provided by block 33, of the battery output upper limit value P _BatMax12 provided by block 34, the smaller the power distributing unit 38 as a battery output upper limit value P _BatMax1 To do. The block 36 is negative indicating that the battery output lower limit value P _BatMin11 provided by block 33, of the battery output lower limit value P _BatMin12 provided by block 34, the larger (typically, battery output lower limit state of charge Therefore, the battery output lower limit value P _BatMin1 may be provided to the power distribution unit 38.

The block 37 stores in advance a map or conversion table representing the correlation between the current charging rate SOC _act of the battery 19 and the battery target output P _BatTgt for making the charging rate SOC _act close to a predetermined SOC target value. Yes. The block 37 obtains the battery target output P _BatTgt based on the map or conversion table and the current charge rate SOC _act of the battery 19 provided from the block 32, and provides this value to the power distribution unit 38.

The power distribution unit 38, the engine output upper limit value P _EngMax, the engine output lower limit value P _EngMin, battery output upper limit value P _BatMax1, battery output lower limit value P _BatMin1, and based on the battery target output P _BatTgt, hydraulic load actual output P _HydOut The electric load actual output P _ElcOut and the assist motor output command P _AsmRef are determined and output to each part of the controller 30.

The hydraulic load actual output P _HydOut is power that is actually supplied to the hydraulic load with respect to the hydraulic load request output P _HydReq . If the required power is always supplied to the hydraulic load request output P _HydReq , the request for the electric load being driven at the same time cannot be satisfied, and the charge rate SOC of the battery 19 cannot be maintained within an appropriate range. For this reason, the power actually supplied to the hydraulic load may have to be limited to some extent.

The electric load actual output P _ElcOut is the electric power actually supplied to the electric load with respect to the electric load required output P _ElcReq . If the required electric power is always supplied to the electric load required output P _ElcReq , the requirement of the hydraulic load being driven at the same time cannot be satisfied, or the charge rate SOC of the battery 19 cannot be maintained within an appropriate range. For this reason, the power actually supplied to the electric load may have to be limited to some extent.

The assist motor output command P _AsmRef is a value that instructs the output of the motor generator 12. The assist motor output command P _AsmRef instructs _whether the motor generator 12 functions as a motor or a generator.

Here, processing for determining the hydraulic load actual output P _HydOut , the electrical load actual output P _ElcOut , and the assist motor output command P _AsmRef in the controller 30 will be described. FIG. 5 is a flowchart of processing performed in the controller 30.

First, in block 31, an engine output upper limit value P _EngMax and an engine output lower limit value P _EngMin of the engine ₁₁ are determined based on the actual engine speed N _act indicating the current speed of the engine 11 (step S1). Next, in blocks 32 to 36, the battery output upper limit value P _BatMax1 and the battery output lower limit value P _BatMin1 are determined based on the current battery voltage V _act (step S2).

Subsequently, in block 37, the battery target output P _BatTgt is determined from the current charging rate SOC _act (step S3). Thereafter, in the power distribution unit 38, the electric load actual output P _ElcOut is determined based on the limit values of the required output of the engine 11 and the battery 19 (step S4), and the hydraulic load actual output P _HydOut is determined as the engine 11 and It is determined based on the limit value of the required output of the battery 19 (step S5). Further, in the power distribution unit 38, the battery output P _BatOut that is a command value of the charge / discharge amount of the battery 19 is determined based on the calculated output of the engine 11, the electric load, and the battery 19 (step S6). . Then, in the power distribution unit 38, the assist motor output command P _AsmRef is determined based on the comparison between the actual electric load output P _ElcOut and the battery output P _BatOut (step S7). As an example, the assist motor output command P _AsmRef is calculated by subtracting the electric load actual output P _ElcOut from the battery output P _BatOut .

  Here, the processing in steps S4 to S6 described above will be described in detail. 6 to 8 are flowcharts of processes in steps S4 to S6.

Referring to FIG. 6, in step S4, first, an electric load output upper limit value P _ElcMax that is the maximum power that can be supplied to the electric load is calculated, and an electric load output lower limit value P _ElcMin that is the electric power that can be stored in the battery 19 is calculated. Is calculated (step S41). Here, the electric load output upper limit value P _ElcMax is the _sum of the engine output upper limit value P _EngMax and the battery output upper limit value P _BatMax1 . That is, the maximum power that can be supplied to the electric load is the sum of the amount of power generated by the motor generator 12 obtained by the maximum output of the engine 11 and the maximum amount of discharge of the battery 19. The electric load output lower limit value P _ElcMin is obtained by subtracting the hydraulic load output request P _HydReq from the value _obtained by adding the engine output lower limit value P _EngMin and the battery output lower limit value P _BatMin1 .

Next, it is determined whether the electrical load required output P _ElcReq is _{equal to} or less than the electrical load output upper limit value P _{ElcMax and} equal to or greater than the electrical load output lower limit value P _ElcMin (step S42). When the electric load required output P _ElcReq is larger than the electric load output upper limit value P _{ElcMax in} step S42 (step S42; No), the value of the electric load actual output P _ElcOut is made equal to the value of the electric load output upper limit value P _ElcMax (step S42). S43). That is, when the power required by the electric load is larger than the maximum power that can be supplied by the motor generator 12 and the battery 19, this maximum power is supplied to the electric load. Further, when the electric load required output P _ElcReq is smaller than the electric load output lower limit value P _ElcMin (step S42; No), the value of the electric load actual output P _ElcOut is made equal to the value of the electric load output lower limit value P _ElcMin (step S43). ). That is, when the electric power regenerated from the electric load is larger than the sum of the maximum power that can be consumed by the motor generator 12 and the maximum power that can be stored in the battery 19, the regenerative power of the electric load does not become larger than this electric power. Like that. When the electrical load required output P _ElcReq is _{equal to} or less than the electrical load output upper limit value P _{ElcMax and} equal to or greater than the electrical load output lower limit value P _ElcMin (step S42; Yes), the value of the electrical load actual output P _ElcOut is set. The electric power required by the electric load is supplied as it is with the electric load request P _ElcReq being equal (step S44).

Referring to FIG. 7, in step S5, first, a hydraulic load output upper limit P _HydMax that is the maximum power that can be supplied to the hydraulic load is calculated (step S51). The hydraulic load output upper limit P _HydMax is calculated by subtracting the electric load actual output P _ElcOut from the value obtained by adding the engine output upper limit P _EngMax and the battery output upper limit P _BatMax .

Next, it is determined whether or not the hydraulic load request output P _HydReq is equal to or less than the hydraulic load output upper limit value P _HydMax (step S52). If the hydraulic load request output P _HydReq is larger than the hydraulic load output upper limit value P _HydMax (step S52; No), the value of the hydraulic load output P _HydOut equal to the hydraulic load output upper limit value P _HydMax (step S53). On the other hand, if the hydraulic load request output P _HydReq is less than the hydraulic load output upper limit value P _HydMax is; made equal to the (step S52 Yes), the hydraulic load output P value the value of the hydraulic load request output P _HydReq the _HydOut, The power required by the hydraulic load is supplied as it is (step S54).

Referring to FIG. 8, in step S6, first, a battery control output upper limit value P _BatMax2 and a battery control output lower limit value P _BatMin2 are calculated (step S61). The battery control output upper limit P _BatMax2 is the _sum of the electric power that can be consumed by the electric load and the electric power that can be consumed by assisting the hydraulic system by the motor generator 12, and the electric load actual output P _ElcOut and the hydraulic load It is calculated by subtracting the engine output lower limit value P _EngMin from the value _obtained by adding the output P _HydOut . The battery control output lower limit value P _BatMin2 is the sum of the regenerative electric power of the electric load and the electric power generated by the motor generator 12, and is _obtained by adding the electric load actual output P _ElcOut and the hydraulic load output P _HydOut. It is calculated by subtracting the engine output upper limit P _EngMax .

Next, the battery control output upper limit value P _BatMax2 and the battery output upper limit value P _BatMax1 are compared, and the battery control output lower limit value P _BatMin2 and the battery output lower limit value P _BatMin1 are compared (step S62). The comparison here is performed for each of the battery output upper limit value P _BatMax1 and the battery output lower limit value P _BatMin1 . When the battery control output upper limit value P _BatMax2 is battery output upper limit value P _BatMax1 more (step S62; Yes), the value of the battery output upper limit value P _BatMax equal to the value of the battery output upper limit value P _BatMax1 (step S63 ). Also, if the battery control output lower limit value P _BatMin2 is less than the battery output lower limit value P _BatMin1 (step S62; Yes), the value of the battery output lower limit value P _BatMin equal to the value of the battery output lower limit value P _BatMin1 (step S63 ).

On the other hand, the battery control output upper limit value P _BatMax2 if the battery output upper limit value P _BatMax1 smaller (step S62; No), the value of the battery output upper limit value P _BatMax equal to the value of the battery control output upper limit value P _BatMax2 (step S64 ). Also, if the battery control output lower limit value P _BatMin2 is larger than the battery output lower limit value P _BatMin1 (step S62; No), the value of the battery output lower limit value P _BatMin equal to the value of the battery control output lower limit value P _BatMin2 (step S64 ).

Subsequently, the battery target output P _BatTgt and the battery output upper limit value P _BatMax are compared, and the battery target output P _BatTgt and the battery output lower limit value P _BatMin are compared (step S65). The comparison here is performed for each of the battery output upper limit value P _BatMax and the battery output lower limit value P _BatMin . If the battery target output P _BatTgt is greater than the battery output upper limit value P _BatMax (step S65; No), the value of the battery output P _BATOUT equal to the value of the battery output upper limit value P _BatMax (step S66). Also, if the battery target output P _BatTgt the battery output lower limit value P _BatMin smaller (step S65; No), the value of the battery output P _BATOUT equal to the value of the battery output lower limit value P _BatMin (step S66).

On the other hand, when the battery target output P _BatTgt is _not more than the battery output upper limit value P _{BatMax and not} less than the battery output lower limit value P _BatMin (step S65; Yes), the value of the battery output P _BatOut is set to the battery target output P _BatTgt. (Step S67).

Here, FIG. 9 is a diagram showing the relationship between the battery charge rate (SOC) and the battery output. In the graph of FIG. 9, the battery output upper limit values P _BatMax11 (thin broken line in the figure) and P _BatMax12 (thick broken line in the figure), and the battery output upper limit value P _BatMax1 (two-dot chain line in the figure) are shown. ing. The battery output upper limit value P _BatMax1 is the smaller value of the battery output upper limit values P _BatMax11 and P _BatMax12 . Similarly, in the graph of FIG. 9, the battery output lower limit values P _BatMin11 (thin alternate long and _short dashed lines in the figure) and P _BatMin12 (thick alternate long and _short dashed lines in the figure), and the battery output lower limit values P _BatMin1 (two points in the figure). A chain line) is shown. The battery output lower limit value P _BatMin1 is the larger value of the battery output lower limit values P _BatMin11 and P _BatMin12 . In this figure, the actual battery output P _BatOut is determined to enter a region smaller than the battery output upper limit value P _BatMax1 on the plus side indicating discharging, and is larger than the battery output lower limit value P _BatMin1 on the minus side indicating charging. Decided to enter.

Further, the battery target output P _BatTgt is also shown in the graph shown in FIG. In this embodiment, in addition to the battery output upper limit value P _BatMax1 and the battery output lower limit value P _BatMin1 , the current charge rate SOC _{act of} the battery 19 is also taken into consideration, and the actual discharge amount or charge amount of the battery 19 is determined as the battery output P _BatOut. Determine as.

As an example, a case where the charge rate SOC _act of the battery 19 is the value (current value) shown in FIG. 9 will be described. At this time, if the battery control output upper limit value P _BatMax2 is smaller than the battery output upper limit value P _BatMax1 as shown in FIG. 9, the battery output upper limit value P _BatMax is set equal to the battery control output upper limit value P _BatMax2 (FIG. 8). Step S64). Further, when the battery target output P _{BatTgt at the} charging rate SOC _act is larger than the battery output upper limit value P _BatMax , the battery output P _BatOut is set equal to the battery output upper limit value P _BatMax (step S66 in FIG. 8).

  The controller 30 having the configuration and functions described above is shown in the battery temperature signal provided from the temperature sensor 44 when an abnormality is detected in the power storage system including the battery 19 and the buck-boost converter 100. When the temperature of the battery 19 exceeds a predetermined value), the output dependency on the engine 11 is relatively increased as compared with the output dependency on the power storage system. In addition, when an abnormality is detected in the engine 11 (specifically, an abnormality signal provided from the ECU 42 indicates an incomplete combustion of the engine 11, an abnormality in the boost pressure of the supercharger 41, or a failure of the water temperature sensor). In the case shown), the output dependency on the power storage system is relatively increased as compared with the output dependency on the engine 11.

  FIG. 10 is a diagram schematically showing processing for increasing the output dependency relative to the engine 11 in comparison with the power storage system when an abnormality is detected in the power storage system including the battery 19 and the buck-boost converter 100. It is. 10A shows a map or conversion table in the block 31 (see FIG. 4) of the controller 30, and FIG. 10B shows a map or conversion in the block 33 (see FIG. 4) of the controller 30. Shows the table.

When an abnormality is detected in the power storage system, the map or conversion table as described below is changed in blocks 31 and 33 of the controller 30. In the block 31, as shown in FIG. 10A, the function indicating the correlation between the engine speed and the engine output upper limit value is changed from the graph G1 to G2 in the figure. That is, the engine output upper limit value at each engine speed is set higher. For example, assuming that the engine output upper limit value corresponding to the actual engine speed N _act at normal time is P _EngMax (1), when an abnormality is detected in the power storage system, it corresponds to the actual engine speed N _act . engine output upper limit value is changed and set to P _EngMax (1) is greater than P _EngMax (2). By increasing the output of the engine 11 in this way, the output dependency on the engine 11 can be relatively increased as compared with the power storage system.

On the other hand, in the block 33, as shown in FIG. 10B, the function indicating the correlation between the charging rate SOC of the battery 19 and the battery output upper limit value is changed from the graph G3 to G4 in the figure, and the battery 19 The function indicating the correlation between the charging rate SOC and the battery output lower limit value is changed from the graph G5 to G6 in the figure. That is, the battery output upper limit value at each charging rate SOC is set lower, and the battery output lower limit value at each charging rate SOC is set higher. For example, assuming that the battery output upper limit value and the battery output lower limit value corresponding to the current charge rate SOC _act at normal times are P _BatMax11 (1) and P _BatMin11 (1), respectively, when an abnormality is detected in the power storage system the battery output upper limit value corresponding to the present charging rate SOC _act is changed and set to P _BatMax11 (1) is less than P _BatMax11 (2), the battery output lower limit value P _BatMin11 (1) is greater than P _BatMin11 (2 ) Is changed. In this way, by suppressing the discharge amount and the charge amount of the battery 19, that is, the output limit value, the output dependency on the engine 11 can be relatively increased as compared with the power storage system.

  The controller 30 performs only one of the setting change in the block 31 (FIG. 10A) and the setting change in the block 33 (FIG. 10B) when an abnormality is detected in the power storage system. Alternatively, both may be performed together.

FIG. 11 shows an example of changes in the engine output P _Eng and the battery output P _Bat before and after the time t ₁ when the power storage system abnormality (overheating of the battery 19) occurs in the power shovel 1 of the present embodiment. It is a graph. In FIG. 11, P _Elc is the power required by the electric load.

11, the abnormality has not occurred in the power storage system at time t _0. At this time, a high output is demanded to the electric load by the operator's lever operation. The controller 30 sets the engine output upper limit value P _EngMax and the battery output upper limit value P so that the value obtained by adding the engine output P _Eng and the battery output P _Bat (P _Eng + P _Bat ) is larger than the required electric power P _{Elc of the} electric load. _{Set BatMax11} and battery output lower limit P _BatMin11 . As a result, the output P _Eng of the engine 11 is stable at P _Eng (1), and the output P _{Bat of the} battery 19 is stable at P _Bat (1).

Here, when the temperature detected by the temperature sensor 44 attached to the battery 19 exceeds a predetermined value, the controller 30 relatively increases the output dependency on the engine 11 as compared with the power storage system. That is, the controller 30 sets the engine output upper limit value at each engine speed higher (see FIG. 10A), lowers the battery output upper limit value at each charge rate SOC, and sets the battery output lower limit value. Is set higher (see FIG. 10B). As a result, the output P _{Eng of the} engine 11 shifts to P _Eng (2) higher than P _Eng (1), and the output P _{Bat of the} battery 19 shifts to P _Bat (2) lower than P _Bat (1). In this case, the value obtained by adding the engine output P _Eng and the battery output P _Bat is maintained, and the electric power P _Elc required by the electric load can be satisfied.

  FIG. 12 is a diagram schematically showing processing for increasing the output dependency on the power storage system relative to the engine 11 when an abnormality is detected in the engine 11. FIG. 12A shows a map or conversion table in the block 31 of the controller 30, and FIG. 12B shows a map or conversion table in the block 33 of the controller 30.

If an abnormality is detected in the engine 11, the map or conversion table as described below is changed in the blocks 31 and 33 of the controller 30. In the block 31, as shown in FIG. 12A, the function indicating the correlation between the engine speed and the engine output upper limit value is changed from the graph G1 to G7 in the figure. That is, the engine output upper limit value at each engine speed is set lower. For example, assuming that the engine output upper limit value corresponding to the actual engine speed N _act at normal time is P _EngMax (1), when an abnormality is detected in the engine 11, the engine actual speed N _act is _handled. engine output upper limit value is changed and set to P _EngMax (1) is less than P _EngMax (3). By suppressing the output of the engine 11 in this way, the output dependency on the power storage system can be relatively increased as compared with the engine 11.

On the other hand, in the block 33, as shown in FIG. 12B, the function indicating the correlation between the charging rate SOC of the battery 19 and the battery output upper limit value is changed from the graph G3 to G8 in the figure, and the battery 19 The function indicating the correlation between the charging rate SOC and the battery output lower limit value is changed from the graph G5 to G9 in the figure. That is, the battery output upper limit value at each charging rate SOC is set higher, and the battery output lower limit value at each charging rate SOC is set lower. For example, assuming that the battery output upper limit value and the battery output lower limit value corresponding to the current charging rate SOC _act at normal times are P _BatMax11 (1) and P _BatMin11 (1), respectively, when an abnormality is detected in the engine 11 the battery output upper limit value corresponding to the present charging rate SOC _act is changed and set to P _BatMax11 (1) is greater than P _BatMax11 (3), the battery output lower limit value P _BatMin11 (1) is less than P _BatMin11 (3 ) Is changed. Thus, by increasing the discharge amount and charge amount of the battery 19, that is, the output limit value, the output dependency on the power storage system can be relatively increased as compared with the engine 11.

  When an abnormality is detected in the engine 11, the controller 30 performs only one of the setting change in the block 31 (FIG. 12 (a)) and the setting change in the block 33 (FIG. 12 (b)). Alternatively, both may be performed together.

13, in the power shovel 1 of the present embodiment, the abnormality of the engine 11 (imperfect combustion of the engine 11, the abnormality of the boost pressure of the turbocharger 41, or failure of the water temperature sensor) before and after the time t ₁ produced It is a graph which shows an example of the mode of a change of engine output P _Eng and battery output P _Bat .

13, the operation of the controller 30 to the time _{t 1} is the same as FIG. 11 described above. Here, when the above-described signal related to the abnormality of the engine 11 is transmitted from the ECU 42, the controller 30 increases the output dependency relative to the power storage system relative to the engine 11. That is, the controller 30 sets the engine output upper limit value at each engine speed lower (see FIG. 12A), sets the battery output upper limit value at each charge rate SOC higher, and sets the battery output lower limit value. Is set lower (see FIG. 12B). As a result, the output P _{Eng of the} engine 11 shifts to P _Eng (3) lower than P _Eng (1), and the output P _{Bat of the} battery 19 shifts to P _Bat (3) higher than P _Bat (1). Even in this case, the value obtained by adding the engine output P _Eng and the battery output P _Bat is maintained, and the electric power P _Elc required by the electric load can be satisfied.

  The effect by the power shovel 1 of this embodiment demonstrated above is demonstrated. As already described, the power shovel 1 includes a power storage system abnormality detection unit such as a temperature sensor 44 that detects the temperature of the battery 19, and the controller 30 stores power when an abnormality of the power storage system is detected. Compared with the system, the output dependency on the engine 11 is relatively increased. Thus, even when an abnormality occurs in the power storage system such as the battery 19, it is possible to prevent the battery charge rate from excessively decreasing and to continue the operation of the power shovel 1. Further, the power shovel 1 includes an engine system abnormality detection unit such as an ECU 42 that detects an abnormality of the engine 11, and the controller 30 compares the output dependency with the engine 11 when an abnormality of the engine 11 is detected. Thus, the output dependency on the power storage system is relatively increased. As a result, even if an abnormality occurs in the engine 11, it is possible to prevent an excessive load from being applied to the driving ability of the engine 11 and to avoid a natural stop of the engine 11.

  Therefore, according to the power shovel 1 of the present embodiment, the operation of the power shovel 1 can be continued for a longer time even when an abnormality occurs in the engine 11, the battery 19, or the like.

  The hybrid construction machine according to the present invention is not limited to the above-described embodiment, and various other modifications are possible. For example, in the above-described embodiment, the power shovel is exemplified as the hybrid construction machine, but the present invention may be applied to other hybrid construction machines (for example, lifting magnet vehicles, wheel loaders, cranes, and the like).

  Moreover, in the said embodiment, although the temperature sensor which detects the temperature of a battery was illustrated as an electrical storage system abnormality detection part, if it is an apparatus which detects the failure of the electrical storage system containing a storage battery and a DC voltage converter, various other The apparatus can be applied to the power storage system abnormality detection unit of the present invention. Further, in the above embodiment, the engine system abnormality detection unit is exemplified by the ECU that detects incomplete combustion of the internal combustion engine engine, boost pressure abnormality of the supercharger, failure of the water temperature sensor, and the like. In addition, various other devices can be applied to the engine system abnormality detection unit of the present invention as long as the device detects a failure of the peripheral device.

  DESCRIPTION OF SYMBOLS 1 ... Power shovel, 2 ... Traveling mechanism, 2a, 2b ... Hydraulic motor, 3 ... Turning mechanism, 4 ... Turning body, 5 ... Boom, 6 ... Arm, 7 ... Bucket, 8 ... Boom cylinder, 9 ... Arm cylinder, 10 DESCRIPTION OF SYMBOLS ... Bucket cylinder, 11 ... Engine, 12 ... Motor generator, 13 ... Reduction gear, 14 ... Main pump, 18 ... Inverter circuit, 19 ... Battery, 20 ... Inverter circuit, 21 ... Electric motor for turning, 29 ... Pressure sensor, 30 DESCRIPTION OF SYMBOLS ... Controller, 38 ... Power distribution part, 39 ... Output condition calculation part, 41 ... Supercharger, 42 ... ECU, 43 ... Injection nozzle sensor, 44 ... Temperature sensor, 100 ... Buck-boost converter, 110 ... DC bus, 120 ... Power storage means.

Claims (5)

An internal combustion engine motor;
A motor generator coupled to the internal combustion engine engine, generating electric power with the driving force of the internal combustion engine engine, and assisting the driving force of the internal combustion engine engine with its own driving force;
An inverter circuit having one end connected to an electrical terminal of the motor generator;
A storage battery connected to the other end of the inverter circuit via a DC voltage converter;
A storage system abnormality detection unit that detects an abnormality of a storage system including the DC voltage converter and the storage battery, and at least one abnormality detection unit of an engine system abnormality detection unit that detects an abnormality of the internal combustion engine engine;
A control unit that adjusts output dependency on each of the power storage system and the internal combustion engine motor by controlling the inverter circuit and the DC voltage converter;
When the storage system abnormality is detected by the storage system abnormality detection unit, the control unit increases the output dependency on the internal combustion engine relative to the output dependency on the storage system. When the abnormality of the internal combustion engine engine is detected in the engine system abnormality detection unit, the output dependency degree relative to the power storage system is relatively increased as compared with the output dependency degree relative to the internal combustion engine engine. Characteristic hybrid construction machine. The hybrid construction machine includes the power storage system abnormality detection unit,
2. The hybrid construction machine according to claim 1, wherein the control unit decreases an output limit value of the storage battery when the storage system abnormality is detected by the storage system abnormality detection unit. The hybrid construction machine includes the power storage system abnormality detection unit,
3. The hybrid according to claim 1, wherein the control unit increases an output upper limit value of the internal combustion engine engine when an abnormality of the power storage system is detected by the power storage system abnormality detection unit. Mold construction machinery. The hybrid construction machine includes the engine system abnormality detection unit,
The said control part reduces the output upper limit of the said internal combustion engine engine, when the abnormality of the said internal combustion engine engine is detected in the said engine system abnormality detection part, The any one of Claims 1-3 characterized by the above-mentioned. The hybrid type construction machine according to claim 1. The hybrid construction machine includes the engine system abnormality detection unit,
The said control part raises the output limit value of the said storage battery, when the abnormality of the said internal combustion engine engine is detected in the said engine system abnormality detection part, The any one of Claims 1-4 characterized by the above-mentioned. Hybrid type construction machine described in 1.

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