JP2010133237A - Hybrid construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid construction machine enhanced in reliability by stopping the drive of a drive and control system of an electrical operation element when an electric motor generator or the drive and control system of the electric motor generator causes a failure. <P>SOLUTION: This hybrid construction machine includes an electric motor generator system which is connected to an internal combustion engine and operates an electric motor generator, a capacitor system connected to the electric motor generator system, a load drive system which is connected to the capacitor system and supplies regenerative power to the capacitor system, an abnormality detection part provided to the electric motor generator system, and a controller for determining an abnormality based on a value detected by the abnormality detection part. When it is determined that the abnormality occurs, the controller stops the drive of the load drive system. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes a hybrid type having a step-up / step-down converter having a step-up switching element and a step-down switching element and performing control of power supply to a load and control of supply of regenerative power obtained from the load to a capacitor Concerning construction machinery.

  Conventionally, a hybrid construction machine in which a part of a drive mechanism is electrically driven has been proposed. Such a construction machine includes a hydraulic pump for hydraulically driving work elements such as a boom, an arm, and a bucket, and a motor generator is connected to an engine for driving the hydraulic pump via a speed reducer. The motor generator assists the drive of the engine, and the power obtained by the power generation is charged in the capacitor.

  In addition to a hydraulic motor as a power source for the turning mechanism for turning the upper turning body, an electric motor is provided in addition to assisting the drive of the hydraulic motor with the electric motor when the turning mechanism is accelerated, and regenerative operation with the electric motor when the turning mechanism is decelerated. The electric power generated is charged in the battery (see, for example, Patent Document 1).

JP-A-10-103112

  By the way, in the conventional hybrid type construction machine, when an abnormality occurs in the assist motor generator or the drive control system of the motor generator, the electric operation to the engine becomes impossible. May not be collected by the power storage means.

  Conversely, when an abnormality occurs in the turning electric motor or the drive control system of the turning electric motor, the electric power generated by the motor generator may not be collected by the power storage means.

  In this case, it is conceivable that the voltage of the power storage means is overvoltage and damaged.

  Therefore, the present invention is a hybrid type that improves reliability by stopping the drive of the drive control system of the electric work element when an abnormality occurs in the motor generator or the drive control system of the motor generator. The purpose is to provide construction machinery.

  A hybrid construction machine according to one aspect of the present invention is connected to an internal combustion engine, and performs a motor power generation operation, a power generation system connected to the motor power generation system, a power storage system connected to the power storage system, and the power storage system. A load drive system that supplies regenerative power, an abnormality detection unit provided in the motor power generation system, and a controller that performs abnormality determination based on a detection value of the abnormality detection unit, wherein the controller has an abnormality If determined, the drive of the load drive system is stopped.

  Further, the controller may continue the charge / discharge control of the power storage system before and after the abnormality determination.

  Further, the load drive system may include a turning electric motor, and when the precursor controller determines that an abnormality has occurred, the driving of the turning electric motor may be stopped.

  The controller is further configured to perform drive control of a hydraulic pump that generates hydraulic pressure, and an abnormality of the motor generator or the drive control system of the motor generator is detected by the abnormality detection unit. In this case, the discharge amount of the hydraulic pump may be limited.

  The load drive system may include a boom regeneration generator, and when the controller determines that an abnormality has occurred, the drive of the boom regeneration generator may be stopped.

  According to the present invention, when an abnormality occurs in the motor generator or the drive control system of the motor generator, the drive control system of the electric work element is stopped by stopping the drive of the drive control system of the electric work element. It is possible to provide a unique effect that a hybrid construction machine that can prevent the above problem can be provided.

1 is a side view illustrating a hybrid type construction machine according to a first embodiment. 1 is a block diagram illustrating a configuration of a hybrid construction machine according to a first embodiment. FIG. 3 is a detailed view of a power storage system used in the hybrid construction machine of the first embodiment. In the conventional hybrid type construction machine, it is a characteristic view which shows transition of DC bus voltage value and battery voltage value when abnormality of the motor generator 12 or the inverter 18 occurs, (a) is a load performing regenerative operation. (B) shows the transition of the voltage value when the load is performing a power running operation. In the hybrid type construction machine of Embodiment 1, it is a characteristic view which shows transition of DC bus voltage value and battery voltage value when abnormality of the motor generator 12 or the inverter 18 occurs. FIG. 5 is a block diagram illustrating a configuration of a hybrid construction machine according to a second embodiment. FIG. 6 is a block diagram illustrating a configuration of a hybrid construction machine according to a third embodiment.

  Embodiments to which the hybrid type construction machine of the present invention is applied will be described below.

“Embodiment 1”
FIG. 1 is a side view showing the hybrid construction machine of the first embodiment.

  This hybrid construction machine is a construction machine type hybrid construction machine, and an upper swing body 3 is mounted on a lower traveling body 1 via a swing mechanism 2. In addition to the boom 4, the arm 5, and the bucket 6, and the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 for hydraulically driving them, the upper swing body 3 is equipped with a cabin 10 and a power source. Is done.

"overall structure"
FIG. 2 is a block diagram illustrating the configuration of the hybrid construction machine according to the first embodiment. In FIG. 2, the mechanical power system is indicated by a double line, the high-pressure hydraulic line is indicated by a solid line, the pilot line is indicated by a broken line, and the electric drive / control system is indicated by a solid line.

  An engine 11 as a mechanical drive unit and a motor generator 12 as an assist drive unit are both connected to an input shaft of a speed reducer 13 as a booster. A main pump 14 and a pilot pump 15 are connected to the output shaft of the speed reducer 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 construction machine according to the first embodiment. The control valve 17 includes hydraulic motors 1A (for right) and 1B (for left) for the lower traveling body 1, The boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 are connected via a high pressure hydraulic line.

  The motor generator 12 is connected to a battery 19 as a battery via an inverter 18 and a step-up / down converter 100 as a power storage controller. The inverter 18 and the buck-boost converter 100 are connected by a DC bus 110.

  Further, a turning electric motor 21 as an electric work element is connected to the DC bus 110 via an inverter 20. The DC bus 110 is disposed for transferring power between the battery 19, the motor generator 12, and the turning motor 21.

  The DC bus 110 is provided with a DC bus voltage detector 111 for detecting a voltage value of the DC bus 110 (hereinafter referred to as a DC bus voltage value). The detected DC bus voltage value is input to the controller 30.

  Further, the battery 19 is provided with a battery voltage detector 112 for detecting the battery voltage value and a battery current detector 113 for detecting the battery current value. The battery voltage value and battery current value detected by these are input to the controller 30. The battery 19, the DC bus 110, and the step-up / down converter 100 constitute a power storage system that transfers power between the motor generator 12 and the turning motor 21.

  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. An operation device 26 is connected to the pilot pump 15 through a pilot line 25. The turning electric motor 21, the inverter 20, the resolver 22, and the turning speed reducer 24 constitute a load control system.

  The operating device 26 includes a lever 26A, a lever 26B, and a pedal 26C. The control valve 17 and the pressure sensor 29 are connected to the lever 26A, the lever 26B, and the pedal 26C through hydraulic lines 27 and 28, respectively. The pressure sensor 29 is connected to a controller 30 that performs drive control of the electric system of the construction machine according to the first embodiment.

  The construction machine according to the first embodiment is a hybrid construction machine that uses the engine 11, the motor generator 12, and the turning electric motor 21 as power sources. These power sources are mounted on the upper swing body 3 shown in FIG. Hereinafter, each part will be described.

"Configuration of each part"
The engine 11 is an internal combustion engine composed of, for example, a diesel engine, and its output shaft is connected to one input shaft of the speed reducer 13. The engine 11 is always operated during the operation of the construction machine.

  The motor generator 12 may be an electric motor capable of both electric (assist) operation and power generation operation. Here, a motor generator that is AC driven by an inverter 18 is shown as the motor generator 12. The motor generator 12 can be constituted by, for example, an IPM (Interior Permanent Magnetic) motor in which a magnet is embedded in a rotor. The rotating shaft of the motor generator 12 is connected to the other input shaft of the speed reducer 13. The motor generator 12 is provided with a temperature sensor 12A as a second abnormality detection unit of the motor generator system. When a load is applied to the motor generator 12, the temperature detection value of the temperature sensor 12A increases. Thereby, if the temperature detection value of the temperature sensor 12A is too high, it can be grasped that the motor generator 12 is in an overload state.

  The speed reducer 13 has two input shafts and one output shaft. A drive shaft of the engine 11 and a drive shaft of the motor generator 12 are connected to each of the two input shafts. Further, the drive shaft of the main pump 14 is connected to the output shaft. When the load on the engine 11 is large, the motor generator 12 performs an electric driving (assist) operation, and the driving force of the motor generator 12 is transmitted to the main pump 14 via the output shaft of the speed reducer 13. Thereby, driving of the engine 11 is assisted. On the other hand, when the load of the engine 11 is small, the driving force of the engine 11 is transmitted to the motor generator 12 through the speed reducer 13, so that the motor generator 12 generates power by the power generation operation. Switching between the power running operation and the power generation operation of the motor generator 12 is performed by the controller 30 according to the load of the engine 11 and the like.

  The main pump 14 is a pump that generates hydraulic pressure to be supplied to the control valve 17. This hydraulic pressure is supplied to drive each of the hydraulic motors 1 </ b> A and 1 </ b> B, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 via the control valve 17.

  The pilot pump 15 is a pump that generates a pilot pressure necessary for the hydraulic operation system. The configuration of this hydraulic operation system will be described later.

  The control valve 17 inputs the hydraulic pressure supplied to each of the hydraulic motors 1A, 1B, the boom cylinder 7, the arm cylinder 8 and the bucket cylinder 9 for the lower traveling body 1 connected via a high-pressure hydraulic line. It is a hydraulic control device which controls these hydraulically by controlling according to the above.

  The inverter 18 is a drive control unit of the motor generator 12 that is provided between the motor generator 12 and the buck-boost converter 100 and that controls the operation of the motor generator 12 based on a control command from the controller 30. Thus, when the inverter 18 is electrically driving the motor generator 12, necessary power is supplied from the battery 19 and the step-up / down converter 100 to the motor generator 12 via the DC bus 110. Further, when the motor generator 12 is in a power generation operation, the battery 19 is charged with the electric power generated by the motor generator 12 via the DC bus 110 and the step-up / down converter 100. The motor generator 12 and the inverter 19 constitute a motor generator system. The inverter 18 is provided with a temperature sensor, a current detector, and a voltage detector (not shown) as an abnormality detection unit of the motor power generation system. In the temperature sensor, the temperature of the switching element of the inverter 18 can be detected, and the current of the motor generator 12 can be detected by the current detector. For example, when the IGBT of the inverter 18 is overloaded, the temperature value detected by the temperature sensor exceeds a predetermined threshold value, so that it can be detected that an abnormality has occurred.

  The battery 19 is connected to the inverter 18 and the inverter 20 via the step-up / down converter 100. Thereby, when at least one of the electric (assist) operation of the motor generator 12 and the power running operation of the turning electric motor 21 is performed, electric power necessary for the electric (assist) operation or the power running operation is supplied. In addition, when at least one of the power generation operation of the motor generator 12 and the regenerative operation of the turning motor 21 is performed, the electric power generated by the power generation operation or the regenerative operation is stored as electric energy. Is the power source.

  The charge / discharge control of the battery 19 is based on the charge state of the battery 19, the operation state of the motor generator 12 (electric (assist) operation or power generation operation), and the operation state (powering operation or regenerative operation) of the turning motor 21. This is done by the buck-boost converter 100. Switching control between the step-up / step-down operation of the step-up / step-down converter 100 is performed by controlling the DC bus voltage value detected by the DC bus voltage detection unit 111, the battery voltage value detected by the battery voltage detection unit 112, and the battery current detection unit 113. Is performed by the controller 30 based on the battery current value detected by.

  The inverter 20 is provided between the turning electric motor 21 and the step-up / down converter 100 and is a drive control unit for the turning electric motor 21 that performs operation control on the turning electric motor 21 based on a control command from the controller 30. . Thereby, when the inverter is operating and controlling the power running of the turning electric motor 21, necessary electric power is supplied from the battery 19 to the turning electric motor 21 through the step-up / down converter 100. Further, when the turning electric motor 21 is performing a regenerative operation, the battery 19 is charged with the electric power generated by the turning electric motor 21 via the step-up / down converter 100. FIG. 2 shows an embodiment including a swing motor (1 unit) and an inverter (1 unit), but by providing a drive unit other than the magnet mechanism and the swing mechanism unit, a plurality of motors and a plurality of inverters are provided. It may be connected to the DC bus 110.

  In addition, this inverter 20 is a drive control part of the electric motor 21 for rotation as an electric work element.

  The buck-boost converter 100 has one side connected to the motor generator 12 and the turning electric motor 21 via the DC bus 110 and the other side connected to the battery 19, so that the DC bus voltage value is within a certain range. Thus, control for switching between step-up and step-down is performed. When the motor generator 12 performs an electric driving (assist) operation, it is necessary to supply electric power to the motor generator 12 via the inverter 18, and thus it is necessary to boost the DC bus voltage value. On the other hand, when the motor generator 12 performs a power generation operation, it is necessary to charge the battery 19 through the inverter 18 with the generated power, and thus it is necessary to step down the DC bus voltage value. The same applies to the power running operation and the regenerative operation of the turning electric motor 21. In addition, the operation state of the motor generator 12 is switched according to the load state of the engine 11, and the turning electric motor 21 is changed to the upper turning body 3. Since the driving state is switched in accordance with the turning operation, the motor generator 12 and the turning motor 21 are either in an electric (assist) operation or a power running operation, and the other is in a power generation operation or a regenerative operation. Can occur.

  For this reason, the step-up / step-down converter 100 performs control to switch between the step-up operation and the 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 disposed between the two inverters 18 and 20 and the step-up / down converter, and is configured to be able to transfer power between the battery 19, the motor generator 12, and the turning electric motor 21. Yes.

  The DC bus voltage detection unit 111 is a voltage detection unit for detecting a DC bus voltage value. The detected DC bus voltage value is input to the controller 30, and is used for switching control between the step-up operation and the step-down operation for keeping the DC bus voltage value within a certain range.

  The battery voltage detection unit 112 is a voltage detection unit for detecting the voltage value of the battery 19 and is used for detecting the state of charge of the battery. The detected battery voltage value is input to the controller 30 and used for switching control between the step-up / step-down operation of the step-up / step-down converter 100.

  The battery current detection unit 113 is a current detection unit for detecting the current value of the battery 19. As the battery current value, a current flowing from the battery 19 to the step-up / down converter 100 is detected as a positive value. The detected battery current value is input to the controller 30 and used for switching control between the step-up / step-down operation of the step-up / down converter 100.

  The turning electric motor 21 may be an electric motor as an electric work element capable of both a power running operation and a regenerative operation, and is provided for driving the turning mechanism 2 of the upper turning body 3. During the power running operation, the rotational force of the rotational driving force of the turning electric motor 21 is amplified by the speed reducer 24, and the upper turning body 3 is subjected to acceleration / deceleration control to perform rotational motion. Further, due to the inertial rotation of the upper swing body 3, the number of rotations is increased by the speed reducer 24 and transmitted to the turning electric motor 21, and regenerative power can be generated. Here, as the electric motor 21 for turning, an electric motor driven by an inverter 20 by a PWM (Pulse Width Modulation) control signal is shown. The turning electric motor 21 can be constituted by, for example, a magnet-embedded IPM motor. Thereby, since a larger induced electromotive force can be generated, the electric power generated by the turning electric motor 21 at the time of regeneration can be increased.

  The resolver 22 is a sensor that detects the rotational position and the rotational angle of the rotating shaft 21A of the turning electric motor 21, and is mechanically connected to the turning electric motor 21 to rotate the rotating shaft 21A before the turning electric motor 21 rotates. The rotation angle and the rotation direction of the rotation shaft 21A are detected by detecting the difference between the position and the rotation position after the left rotation or the right rotation. By detecting the rotation angle of the rotation shaft 21A of the turning electric motor 21, the rotation angle and the rotation direction of the turning mechanism 2 are derived. Further, FIG. 2 shows a form in which the resolver 22 is attached, but an inverter control system that does not have an electric motor rotation sensor may be used.

  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. This mechanical brake 23 is switched between braking and release by an electromagnetic switch. This switching is performed by 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 2. Thereby, in the power running operation, the rotational force of the turning electric motor 21 can be increased and transmitted to the turning body as a larger rotational force. On the contrary, during the regenerative operation, the number of rotations generated in the revolving structure can be increased, and more rotational motion can be generated in the turning electric motor 21.

  The turning mechanism 2 can turn in a state where the mechanical brake 23 of the turning electric motor 21 is released, whereby the upper turning body 3 is turned leftward or rightward.

  The operating device 26 is an operating device for operating the turning electric motor 21, the lower traveling body 1, the boom 4, the arm 5, and the bucket 6, and is operated by a driver of the hybrid type construction machine.

  The operating device 26 converts the hydraulic pressure (primary hydraulic pressure) supplied through the pilot line 25 into hydraulic pressure (secondary hydraulic pressure) corresponding to the operation amount of the driver and outputs the converted 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.

  When the operation device 26 is operated, the control valve 17 is driven through the hydraulic line 27, thereby controlling the hydraulic pressure in the hydraulic motors 1 </ b> A and 1 </ b> B, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9. The lower traveling body 1, the boom 4, the arm 5, and the bucket 6 are driven.

  The hydraulic line 27 supplies hydraulic pressure necessary for driving the hydraulic motors 1A and 1B, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder to the control valve.

  When the operation for turning the turning mechanism 2 is input to the operating device 26, the pressure sensor 29 as the turning operation detection unit detects the operation amount as a change in the hydraulic pressure in the hydraulic line 28. The pressure sensor 29 outputs an electrical signal indicating the hydraulic pressure in the hydraulic line 28. Thereby, the operation amount for turning the turning mechanism 2 input to the operating device 26 can be accurately grasped. This electric signal is input to the controller 30 and used for driving control of the turning electric motor 21. In the first embodiment, a description will be given of a mode in which a pressure sensor is used as a lever operation detection unit. However, a sensor that reads an operation amount for turning the turning mechanism 2 input to the operating device 26 as an electric signal is used. May be.

"Controller 30"
The controller 30 is a control device as a main control unit that performs drive control of the hybrid type construction machine according to the first embodiment, and includes a CPU (Central Processing Unit) and an arithmetic processing unit including an internal memory. This is an apparatus realized by executing a drive control program stored in the computer.

  The controller 30 converts a signal input from the pressure sensor 29 (a signal indicating an operation amount for turning the turning mechanism 2 input to the operation device 26) into a speed command, and performs drive control of the turning electric motor 21. .

  In addition, the controller 30 performs operation control of the motor generator 12 (switching between electric (assist) operation or power generation operation) and also performs charge / discharge control of the battery 19 by drivingly controlling the buck-boost converter 100. The controller 30 is a step-up / down converter based on the state of charge of the battery 19, the operation state of the motor generator 12 (electric (assist) operation or power generation operation), and the operation state (powering operation or regenerative operation) of the turning motor 21. Switching control between 100 step-up operation and step-down operation is performed, and thereby charge / discharge control of the battery 19 is performed.

  Switching control between the step-up / step-down operation of the step-up / step-down converter 100 is performed by controlling the DC bus voltage value detected by the DC bus voltage detection unit 111, the battery voltage value detected by the battery voltage detection unit 112, and the battery current detection unit 113. This is performed based on the battery current value detected by.

  Further, the controller 30 sets a detection value from the abnormality detection unit disposed in the motor generator 12 and the inverter 18 detected by the abnormality detection unit, and a predetermined threshold corresponding to each abnormality detection unit. It carries out the function of performing abnormality determination by comparing. For this reason, the controller 30 includes the temperature of the motor generator 12, the current value flowing through the motor generator 12, the voltage value applied to the motor generator 12, the temperature of the switching element included in the inverter 18, A signal representing a supplied voltage value and a current value supplied to the inverter 18 is input.

  The abnormality of the motor generator 12 refers to, for example, a case where the motor generator 12 is disconnected or a temperature that is abnormally increased.

  Further, the abnormality of the inverter 18 means that the temperature, voltage value, or current value of the switching element exceeds the respective threshold value due to disconnection or failure, and an overheat state, an overvoltage state, or an overcurrent state occurs. Say.

  FIG. 3 is a detailed view of a power storage system used in the hybrid construction machine of the first embodiment. The step-up / down converter 100 includes a reactor 101, a boosting IGBT (Insulated Gate Bipolar Transistor) 102A, a step-down IGBT 102B, a power connection terminal 104 for connecting the battery 19, an output terminal 106 for connecting an inverter 105, and A smoothing capacitor 107 inserted in parallel with the pair of output terminals 106 is provided. The output terminal 106 of the buck-boost converter 100 and the inverter 105 are connected by a DC bus 110. The inverter 105 corresponds to the inverters 18A, 18B, and 20.

  Reactor 101 has one end connected to an intermediate point between boosting IGBT 102A and step-down IGBT 102B, and the other end connected to power supply connection terminal 104. It is provided for supplying to the DC bus 9.

  The step-up IGBT 102 </ b> A and the step-down IGBT 102 </ b> B are semiconductor elements that are configured by bipolar transistors in which a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is incorporated in a gate portion and can perform high-power high-speed switching. The step-up IGBT 102A and the step-down IGBT 102B are driven by the drive control unit 120 by applying a PWM voltage to the gate terminal. Diodes 102a and 102b, which are rectifying elements, are connected in parallel to the step-up IGBT 102A and the step-down IGBT 102B.

  The battery 19 may be a chargeable / dischargeable battery so that power can be exchanged with the DC bus 110 via the buck-boost converter 100. 3 shows the battery 19 as a capacitor, the capacitor 19 may be replaced with a capacitor, a chargeable / dischargeable secondary battery, or another form of power source capable of power transfer. Good.

  The power connection terminal 104 and the output terminal 106 may be terminals that can be connected to the battery 19 and the inverter 105. A battery voltage detector 112 that detects the battery voltage is connected between the pair of power connection terminals 104. A DC bus voltage detector 111 that detects a DC bus voltage is connected between the pair of output terminals 106.

  The battery voltage detector 112 detects the voltage value (vbat_det) of the battery 19, and the DC bus voltage detector 111 detects the voltage of the DC bus 110 (hereinafter, DC bus voltage: vdc_det).

  The smoothing capacitor 107 may be any storage element that is inserted between the positive terminal and the negative terminal of the output terminal 106 and can smooth the DC bus voltage.

  The battery current detection unit 113 may be any detection means capable of detecting the value of the current flowing through the battery 19 and includes a current detection resistor. The reactor current detection unit 108 detects a current value (ibat_det) flowing through the battery 19.

"Buck-boost operation"
In such a step-up / down converter 100, when boosting the DC bus 110, a PWM voltage is applied to the gate terminal of the boosting IGBT 102A, and the boosting IGBT 102A is connected via the diode 102b connected in parallel to the step-down IGBT 102B. The induced electromotive force generated in the reactor 101 when the power is turned on / off is supplied to the DC bus 110. Thereby, the DC bus 110 is boosted.

  When the DC bus 110 is stepped down, a PWM voltage is applied to the gate terminal of the step-down IGBT 102 </ b> B, and regenerative power supplied via the step-down IGBT 102 </ b> B and the inverter 105 is supplied from the DC bus 110 to the battery 19. As a result, the power stored in the DC bus 110 is charged in the battery 19 and the DC bus 110 is stepped down.

  In practice, a drive unit that generates a PWM signal for driving the boosting IGBT 102A and the step-down IGBT 102B exists between the controller 120 and the step-up IGBT 102A and the step-down IGBT 102B, but is omitted in FIG. Such a driving unit can be realized by either an electronic circuit or an arithmetic processing unit.

  Here, when an abnormality occurs in the motor generator 12 or the inverter 18, excessive power is supplied to the inverter 20, and the inverter 20 may be damaged.

  For this reason, in the hybrid type construction machine of the first embodiment, when an abnormality occurs in the motor generator 12 or the inverter 18, the drive control unit 120 stops the drive of the inverter 20. The operating characteristics at this time will be described with reference to FIGS.

  FIG. 4 is a characteristic diagram showing the transition of the DC bus voltage value and the battery voltage value when an abnormality occurs in the motor generator 12 or the inverter 18 in the conventional hybrid construction machine. FIG. When the operation is performed, (b) shows the transition of the voltage value when the load is performing the power running operation.

  FIG. 5 is a characteristic diagram showing the transition of the DC bus voltage value and the battery voltage value when an abnormality occurs in the motor generator 12 or the inverter 18 in the hybrid type construction machine of the first embodiment.

In these figures, the vertical axis indicates the voltage value, V1 is the target value of the DC bus voltage value, V2 is the upper limit value of the DC bus voltage value, V4 is the lower limit value of the battery usage range, _VDC is the DC bus voltage value, V _BAT represents a battery voltage value.

  Here, the upper limit value V2 of the DC bus voltage value is a voltage value for determining whether or not the DC bus voltage value is an overvoltage.

  The battery usage range is a range of battery voltage values when using the battery 19 in the hybrid construction machine, and FIG. 4B shows only the lower limit value V4.

  4A and 4B show characteristics when an abnormality occurs in the inverter 18. Before the time t = 0, the regenerative operation of the turning electric motor 21 is performed in FIG. 4A. In FIG. 4B, it is assumed that the power running operation is performed.

As shown in FIG. 4A, at time t = 0, the DC bus voltage value V _DC is higher than the battery voltage value V _BAT .

In the conventional hybrid type construction machine, even if an abnormality occurs in the inverter 18 at time t = 0, the drive control of the turning electric motor 21 that is an electric work element is not stopped, so the electric power regenerated by the turning electric motor 21 is Supplied to the DC bus 110. As a result, the controller 30 causes the buck-boost converter 100 to perform a step-down operation in order to keep the DC bus voltage value V _DC constant, so that the battery voltage value V _BAT increases.

  At time t = t2, the battery voltage value Vbat reaches the DC bus voltage value Vdc. Thereafter, when regeneration from the turning electric motor 21 continues, both the battery voltage value Vbat and the DC bus voltage value Vdc are increased.

  Furthermore, at time t = t3, the upper limit value of the DC bus voltage value is reached. In this case, the inverter 20 is overvoltaged and damaged.

Further, as shown in FIG. 4B, at time t = 0, the DC bus voltage value V _DC is higher than the battery voltage value V _BAT .

As described above, in the conventional hybrid type construction machine, even if an abnormality occurs in the inverter 18 at time t = 0, the drive control of the turning electric motor 21 that is an electric work element is not stopped. The power of the bus 110 is consumed. As a result, the drive control unit 120 causes the step-up / step-down converter 100 to perform a boost operation in order to keep the DC bus voltage value _VDC constant, so that the battery voltage value V _BAT decreases.

By continuing the electric operation of the turning electric motor 21, the battery voltage value _VBAT falls below the lower limit value V4 of the battery usage range at time t = t4. When the battery voltage value V _BAT is lower than the lower limit value V4, the output of the battery 19 decreases, so that normal operation cannot be performed.

  On the other hand, in the hybrid construction machine of the first embodiment, even if an abnormality occurs in the inverter 18, damage to the inverter 20 can be prevented as follows.

  FIG. 5 shows time transitions of the battery voltage value and the DC bus voltage value after the occurrence of abnormality in the inverters 18 and 20 when the first embodiment is used.

  When the hybrid construction machine continues to work, the motor generator 12 is overloaded, and the detection value by the temperature sensor 12A disposed in the motor generator 12 reaches a predetermined temperature, the controller 30 causes the motor generator 12 to Is overloaded (time t = 0). In this case, the controller 30 determines that an abnormality has occurred in the motor power generation system. Then, a control command is sent to the inverter 18 so as to stop the driving of the motor generator 12 in order to perform the abnormality process. Furthermore, the controller 30 sends a control command to the inverter 20 so as to stop the drive control of the turning electric motor 21. Thereby, generation | occurrence | production of the regenerative electric power in the electric motor 21 for a rotation can be prohibited, and also the power consumption by power running operation is prohibited. On the other hand, the controller 30 sends a control command to the buck-boost converter 100 so as to continuously maintain the DC bus voltage Vdc at V1 before and after the occurrence of abnormality in the motor power generation system.

Thereby, after t = 0, as shown in FIG. 5, the DC bus voltage value V _DC and the battery voltage value V _BAT are held at constant values. For this reason, the inverter 20 is not damaged.

It should be noted that, in the case where an abnormality occurs in the motor generator 12 instead of the inverter 18, similarly, the drive control of the inverter 20 is stopped by the drive control unit 120, and the DC bus voltage value V _DC and the battery voltage are stopped. The value V _BAT is held at a constant value. For this reason, the inverter 20 is not damaged.

  As described above, in the hybrid construction machine of the first embodiment, when an abnormality occurs in the motor generator 12 or the inverter 18 that is a drive control system thereof, the drive control of the inverter 20 is stopped by the drive control unit 120. For this reason, damage to the inverter 20 can be prevented.

Note that after the drive control of the inverters 18 and 20 is stopped, the DC bus voltage value V _DC and the battery voltage value V _BAT are held at constant values. For this reason, after the inverter 18A is restored, the normal operation can be performed promptly.

  Further, when an abnormality occurs in the motor generator 12 or the inverter 18, the controller 30 may limit (decrease) the discharge amount of the main pump 14. Thereby, even when the output of the motor generator 12 decreases due to an abnormality occurring in the motor generator 12 or the inverter 18, the load when the engine 11 drives the main pump 14 can be reduced. For this reason, when abnormality occurs in the motor generator 12 or the inverter 18, the engine 11 can be prevented from stalling by limiting the discharge amount.

[Embodiment 2]
FIG. 6 is a block diagram illustrating a configuration of the hybrid type construction machine of the second embodiment. The hybrid type construction machine of the second embodiment is that the boom regenerative generator 300 as an electric work element is connected to the DC bus 110 via an inverter 18B as a drive control system. Different from construction machinery. The inverter 18B and the boom regeneration generator 300 constitute a load drive system.

  In the hybrid type construction machine of the second embodiment, the hydraulic motor 310 is connected to the boom cylinder 7, and the rotating shaft of the boom regeneration generator 300 is driven by the hydraulic motor 310. In FIG. 6, the hydraulic motor 310 and the boom regeneration generator 300 are separated from each other for convenience of explanation, but actually, the rotation shaft of the boom regeneration generator 300 is mechanically connected to the rotation shaft of the hydraulic motor 310. It is connected to the.

  As described above, the boom regeneration generator 300 is an electric work element that is driven by the hydraulic motor 310 and converts potential energy into electrical energy when the boom 4 is lowered according to gravity.

  The hydraulic motor 310 is configured to be rotated by oil discharged from the boom cylinder 7 when the boom 4 is lowered, and is provided to convert energy when the boom 4 is lowered according to gravity into rotational force. It has been. Since the hydraulic motor 310 is provided in the hydraulic pipe 7 </ b> A between the control valve 17 and the boom cylinder 7, it can be attached to an appropriate place in the upper swing body 3.

  The electric power generated by the boom regenerative generator 300 is supplied as regenerative energy to the DC bus 110 via the inverter 18B.

  For this reason, the motor generator 12 and the turning motor 21 may be supplied with power via the DC bus 110. In addition, the motor generator 12, the boom regeneration generator 300, and the turning motor 21 may be supplied with power from any one of them.

  In the second embodiment, the step-up / step-down converter 100 boosts the DC bus voltage value within a certain range according to the operating state of the motor generator 12, the boom regeneration generator 300, and the turning motor 21. Control to switch operation and step-down operation.

  The DC bus 110 is disposed between the inverters 18A, 18B, and 20 and the step-up / down converter, and power is supplied between the battery 19, the motor generator 12, the boom regeneration generator 300, and the turning motor 21. Give and receive.

  In such a hybrid construction machine of the second embodiment, when an abnormality occurs in the inverter 18A at time t = 0, the drive control unit 120 stops the drive control of the inverters 18B and 20, and the boom regeneration generator 300 and the drive control of the turning electric motor 21 are stopped.

  Thereby, when an abnormality occurs in the motor power generation system, supply of regenerative energy from the inverter 18B to the DC bus 110 can be prevented.

Thereby, the DC bus voltage value V _DC and the battery voltage value V _BAT are held at a constant value. For this reason, the inverters 18B and 20 are not damaged.

It should be noted that, in the case where an abnormality occurs in the motor generator 12 instead of the inverter 18A, the DC bus voltage value V _DC and the battery voltage value V _BAT are similarly held at a constant value. For this reason, the inverters 18B and 20 are not damaged.

  Thus, in the hybrid type construction machine of the second embodiment, when an abnormality occurs in the motor generator 12 or the inverter 18 that is a drive control system thereof, the drive control of the inverters 18B and 20 is stopped by the drive control unit 120. The For this reason, damage to inverters 18B and 20 can be prevented.

Note that after the drive control of the inverters 18B and 20 is stopped, the DC bus voltage value V _DC and the battery voltage value V _BAT are held at constant values. For this reason, after the inverter 18A is restored, the normal operation can be performed promptly.

  In the above description, the boom regenerative generator 300 converts the positional energy of the boom 4 into electric energy via the hydraulic motor 310. However, the boom regenerative generator 300 is connected to the boom shaft of the boom 4. The power generation may be performed when the boom 4 is driven by hydraulic pressure when the boom 4 is lowered. Whether the boom 4 is raised or lowered is determined, for example, by providing a pressure sensor on the secondary side of the operation lever 26A for operating the boom 4 and the drive control unit 120 based on the output of the pressure sensor. That's fine.

[Embodiment 3]
FIG. 7 is a block diagram showing a configuration of the hybrid type construction machine of the third embodiment. The hybrid construction machine of the third embodiment is configured such that the main pump 14 is driven by the pump motor 400, and the motor generator 12 performs power recovery (power generation operation) by being driven by the engine 11. This is different from the hybrid construction machine of the first embodiment. Since the other configuration is the same as that of the hybrid construction machine of the first embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted. In the present embodiment, the motor generator 12 has a function as a generator that performs only a power generation operation by being driven by the engine 11.

  The pump motor 400 is configured to perform only a power running operation for driving the main pump 14, and is connected to the DC bus 110 via an inverter 410 as a drive control system.

  The pump motor 400 is configured to be driven by the drive control unit 120. When any of the levers 26A to 26C is operated, electric power is supplied to the pump motor 400 from the DC bus 110 via the inverter 410, thereby performing a power running operation, and the pump 14 is driven to pressurize the pressure oil. Is discharged.

  For this reason, the motor generator 12, the pump motor 400, and the turning motor 21 may be supplied with power via the DC bus 110. In addition, the motor generator 12 and the turning electric motor 21 may have a situation where power is supplied to the DC bus 110 from either one.

  In the third embodiment, the step-up / step-down converter 100 performs step-up operation so that the DC bus voltage value falls within a certain range in accordance with the operating states of the motor generator 12, the pump motor 400, and the turning motor 21. Control to switch the step-down operation.

  The DC bus 110 is disposed between the inverters 18, 410, and 20 and the step-up / down converter 100, and transfers power between the battery 19, the pump motor 400, and the turning motor 21.

  In such a hybrid construction machine of the third embodiment, when an abnormality occurs in the inverter 18 at time t = 0, the drive control unit 120 stops the drive control of the inverters 20 and 410, and the turning electric motor 21 and the pump The drive control of the motor 400 is stopped.

Thereby, the DC bus voltage value V _DC and the battery voltage value V _BAT are held at a constant value. For this reason, the inverters 20 and 410 are not damaged.

It should be noted that, in the case where an abnormality occurs in the motor generator 12 instead of the inverter 18, the DC bus voltage value V _DC and the battery voltage value V _BAT are similarly held at a constant value. For this reason, the inverters 20 and 410 are not damaged.

  As described above, in the hybrid type construction machine of the third embodiment, when an abnormality occurs in the motor generator 12 or the inverter 18 that is a drive control system thereof, the drive control of the inverters 20 and 410 is stopped by the drive control unit 120. . For this reason, damage to inverters 20 and 410 can be prevented.

Note that after the drive control of the inverters 20 and 410 is stopped, the DC bus voltage value V _DC and the battery voltage value V _BAT are held at constant values. For this reason, after the inverter 18 is restored, normal operation can be performed promptly.

  As described above, in the first to third embodiments, the hybrid type construction machine having various configurations has been described. However, the hybrid type construction machine of the present invention can arbitrarily combine the configurations shown in the first to fourth embodiments.

  The hybrid construction machine according to the exemplary embodiment of the present invention has been described above, but the present invention is not limited to the specifically disclosed embodiment and departs from the scope of the claims. Various modifications and changes are possible.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 1A, 1B Traveling mechanism 2 Turning mechanism 3 Upper turning body 4 Boom 5 Arm 6 Bucket 7 Boom cylinder 7A Hydraulic pipe 8 Arm cylinder 9 Bucket cylinder 10 Cabin 11 Engine 12 Motor generator 13 Reducer 14 Main pump 15 Pilot Pump 16 High pressure hydraulic line 17 Control valve 18, 18A, 18B, 20, 410 Inverter 19 Battery 21 Electric motor for turning 22 Resolver 23 Mechanical brake 24 Turning reduction gear 25 Pilot line 26 Operating device 26A, 26B Lever 26C Pedal 26D Button switch 27 Hydraulic pressure Line 28 Hydraulic line 29 Pressure sensor 30 Controller 100 Buck-boost converter 101 Reactor 102A Boosting IGBT
102B IGBT for step-down
DESCRIPTION OF SYMBOLS 103 Battery 104 Power supply connection terminal 105 Motor 106 Output terminal 107 Capacitor 110 DC bus 111 DC bus voltage detection part 112 Battery voltage detection part 113 Battery current detection part 300 Generator 310 Hydraulic motor 400 Pump motor

Claims (5)

A motor generator system connected to an internal combustion engine and performing a motor generator operation;
A power storage system connected to the motor power generation system;
A load driving system connected to the power storage system and supplying regenerative power to the power storage system;
An abnormality detector provided in the motor power generation system;
A hybrid construction machine that includes: a controller that performs abnormality determination based on a detection value of the abnormality detection unit, and the controller stops driving the load drive system when determining that an abnormality has occurred.   The hybrid-type construction machine according to claim 1, wherein the controller continues charge / discharge control of the power storage system before and after abnormality determination. The load drive system includes a turning electric motor,
The hybrid construction machine according to claim 1, wherein when the precursor controller determines that an abnormality has occurred, the precursor controller stops driving the electric motor for turning.   The controller is further configured to perform drive control of a hydraulic pump that generates hydraulic pressure, and when the abnormality detector detects an abnormality of the motor generator or the drive control system of the motor generator. The hybrid construction machine according to any one of claims 1 to 3, wherein a discharge amount of the hydraulic pump is limited. The load drive system includes a boom regeneration generator,
The hybrid construction machine according to any one of claims 1 to 4, wherein when the controller determines that an abnormality has occurred, the controller stops driving the boom regeneration generator.

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