JP2007228721A - Failure prevention device for regeneration and power factor function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure prevention device for a regeneration and power factor function that can suppress the deterioration of a regeneration brake function, and can recover it by discriminating a sign of a failure before the brake function possessed by an electric motor is failed. <P>SOLUTION: The failure prevention device for the regeneration and power factor function comprises: a failure sign discrimination circuit 21 that discriminates the state of the sign before the failure of the regeneration brake function occurs when the electric motor is used as a generator; and a function deterioration suppression and recovery circuit 22 that suppress the deterioration of the regeneration brake function of the electric motor and the deterioration of a driving function, and recovers them by decelerating the driving speed or the acceleration/deceleration speed of the electric motor by discriminating the state of the sign before the failure caused by the failure sign discrimination circuit 21 occurs. The failure sign discrimination circuit 21 comprises: an unexpected temperature rise discrimination means 21a that detects at least the temperature of either the electric motor or an inverter, and discriminates a state that the temperature is unexpectedly raised; and an unexpected speed difference discrimination means 21b or the like that detects the working speed of a working body operated by the electric motor, and discriminates a state that a speed difference between the working speed and a command speed commanded by an operation signal is an unexpected difference. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a regenerative / power running function failure prevention device that prevents a failure of a regenerative braking function and a power running side function of an electric motor.

  In a hybrid system such as a hybrid vehicle, the regenerative braking function of the electric motor is used to assist in stopping the vehicle body and recover energy. Furthermore, the vehicle body is stopped by another mechanical brake that is operated by a driver pressing a pedal or the like.

In addition, there is a hybrid construction vehicle including a hybrid system in which stop assistance and energy recovery are achieved by a regenerative braking function when an electric motor is used as a generator (see, for example, Patent Document 1).
Japanese Patent Laying-Open No. 2005-133319 (page 4-5, FIG. 1)

  However, the conventional hybrid system has a function of detecting a precursor of a failure of the regenerative braking function of the electric motor (including a deterioration of the regenerative braking function and an operation exceeding the use condition) and a function of performing a suppression process. However, if the regenerative braking function is impaired, there is a problem that the recovery is not easy and there is a concern about a safety stop.

  Similarly, there is no function to detect a sign of a failure in the power running function of the motor (although this is not a problem in terms of safety stop) or a function to suppress it. There is a problem that is not easy to recover.

  In addition, there is a problem that the capacity of the equipment increases in order to expand the usage conditions of equipment such as an electric motor in a wide range and cope with various usage conditions.

  The present invention has been made in view of the above points, and before the regenerative brake function and the power running side function of the electric motor break down, the precursor is identified to suppress the deterioration of the regenerative brake function and the power running side function and recover. Therefore, an object of the present invention is to provide a regenerative / power running function failure prevention device capable of avoiding the problem of safety stop, improving reliability, ensuring operation continuity, and optimizing the equipment capacity.

  According to the first aspect of the present invention, there is provided an electric motor having a regenerative brake function and operating an operating body, and a failure sign determination for determining a precursor state before failure of the regenerative brake function when used as a power running side function and a generator of the electric motor. Degradation suppression function that suppresses and restores the power running side function and regenerative braking function of the motor by reducing the supply / recovery power of the motor by determining the pre-failure state by the circuit and this failure sign determination circuit A regenerative / power running function failure prevention device including a recovery processing circuit.

  In the invention according to claim 2, the failure sign determination circuit in the regeneration / power running function failure prevention device according to claim 1 detects the temperature of at least one of the motor and the inverter that controls the motor, and this temperature is unexpected. An unexpected temperature rise discrimination means for discriminating a state where the temperature is increased, and an operating speed of the operating body operated by the electric motor or an electric motor operating speed are detected, and a speed deviation between the operating speed and a command speed commanded by an operation signal is detected. Is an unexpected speed deviation determining means for determining an unexpected state, an equipment function lowering determining means for detecting a state of the equipment constituting the motor and the inverter to determine a function deterioration of the equipment, an unexpected temperature rise determining means, An ON signal that outputs an ON signal to the function deterioration suppression / recovery processing circuit by an ON signal from at least one of the unexpected speed deviation determination means and the equipment function deterioration determination means. It is obtained; and a circuit.

  According to a third aspect of the present invention, the regeneration / power running function failure prevention device according to the first or second aspect includes a power storage device that stores electric power generated from an electric motor that functions as a generator, and the failure sign determination circuit includes the power storage device Unexpected bus voltage determination means for detecting an unexpected decrease and increase in the bus voltage by detecting the bus voltage between the motor and the motor, and an unexpected decrease and increase in the storage state by detecting the storage state of the power storage device And an unexpected storage state determination means for determining

  According to a fourth aspect of the present invention, the failure symptom determination circuit in the regeneration / power running function failure prevention device according to any one of the first to third aspects comprises a phenomenological phenomenon display / memory device for displaying and storing a phenomenological phenomenon. is there.

  According to a fifth aspect of the present invention, the function lowering suppression / recovery processing circuit in the regeneration / powering functional failure prevention device according to any one of the first to fourth aspects suppresses the operating body power or the acceleration / deceleration of the operating body. Actuator power suppression circuit that outputs a signal, the actuator power suppression circuit outputs a power running side power suppression signal, and the power running side speed of the regenerative brake safety stop use target system is suppressed, and its operation On the condition that the operating speed of the body is lowered, the regeneration body power suppression signal is output.

  According to a sixth aspect of the invention, the regeneration / power running function failure prevention device according to any one of the first to fifth aspects is applied to an electric motor of a hybrid work machine.

  According to the first aspect of the present invention, the failure precursor determination circuit and the function deterioration suppression / recovery processing circuit determine the precursor state before the failure of the regenerative braking function and the power running side function, and the supply / recovered power of the motor is reduced. By suppressing and reducing the deterioration of the regenerative braking function and the power running side function of the electric motor, it is possible to prevent the regenerative braking function and the power running side function of the motor from being damaged.

  According to the second aspect of the present invention, the unexpected temperature rise of the electric motor and its inverter and the unexpected operating body are detected by the unexpected temperature rise determining means, the unexpected speed deviation determining means, the equipment function deterioration determining means and the OR circuit. Even if any of the regenerative braking function and power running side function degradation of the speed deviation of the machine and the function degradation of the equipment occurs, the function degradation is suppressed and restored, so the motor regenerative braking function and power running side function will fail. Can be prevented in advance.

  According to the third aspect of the present invention, the unexpected bus voltage determination unit and the unexpected storage state determination unit include a failure sign on the power running side and a failure sign on the regeneration side due to an unexpected decrease and increase in the bus voltage and storage state. Therefore, it is possible to easily cope with suppression / recovery processing of functional degradation.

  According to the invention described in claim 4, since the cause of the failure precursor phenomenon can be confirmed by the precursor phenomenon display / storage device, it can be utilized for the investigation and can be easily dealt with by maintenance.

  According to the fifth aspect of the invention, the temperature rise or the like is caused not only by regeneration but also by excessive power on the power running side, and when this progresses, a regenerative brake failure occurs. There is no particular restriction on the power control on the power running side, but there is no particular restriction on the power control on the power running side. Since the confirmation that there is no problem is the condition for suppression, first, if the operating speed or acceleration / deceleration of the regenerative brake safety stop use target system is suppressed and the operating speed has decreased, the regenerative braking function Since it is confirmed that there is no problem even if the operation is suppressed, the regenerative side actuator power suppression signal is output from the operating body power suppression circuit. The suppression of the key function can prevent the risk of safety stop function is impaired. By this regenerative brake function suppression / recovery process, temperature rise, overdischarge / overcharge of the power storage device, etc. are alleviated, and the recovery brake function can be recovered.

  According to the sixth aspect of the present invention, the precursor state before the failure of the regenerative braking function and the power running side function of the electric motor of the hybrid work machine is discriminated and processed to reduce the function of the regenerative braking function and the power running side function of the electric motor. Since it is suppressed and restored, it is possible to prevent the regenerative braking function of the hybrid work machine from being damaged and the safety stop function from being impaired. Moreover, since it can cope with the operation exceeding the use condition of the electric motor, it is possible to avoid an unnecessary increase in the equipment capacity due to the wide use condition. As a result, it is possible to actively work on energy recovery by regenerative braking and efficiency improvement thereby.

  Hereinafter, the present invention will be described in detail with reference to one embodiment shown in FIGS.

  FIG. 2 shows a hybrid system mounted on a hybrid hydraulic excavator 1 as a hybrid work machine. The lower traveling body 2 as an operating body having left and right crawler belts respectively driven by left and right traveling electric motors 2m, An upper swing body 3 as an actuating body is provided so as to be able to swivel by a turning electric motor 3m, and a power device 4 and a working device 5 as an actuating body are mounted on the upper swing body 3. The left and right traveling motors 2m and the turning motor 3m are provided with mechanical brakes such as electromagnetic brakes (not shown) that are generally used during emergency stops.

  In the working device 5, a boom 6 that is turned up and down by a boom cylinder 6c with respect to the upper swing body 3 is pivotally supported, and an arm 7 that is turned by an arm cylinder 7c is rotatable at the tip of the boom 6. A bucket 8 that is rotated by a bucket cylinder 8c is pivotally supported at the tip of the arm 7.

  In the power unit 4, an engine 11 and an electric motor 12 are connected to pumps 14a and 14b via a power transmission unit 13, and left and right traveling motors 2m, turning motors 3m and motors 12 (hereinafter simply referred to as "motors 2m and 3m"). , 12 ”) is connected to an electric storage device 17 such as a battery for storing electric power generated from the electric motors 2m, 3m, 12 functioning as a generator via an inverter 15 and a converter 16. The power transmission device 13 incorporates a clutch mechanism for intermittently connecting the engine 11, the electric motor 12, and the pumps 14a and 14b.

  Each of the motors 2m, 3m, and 12 receives the supply of electric power from the power storage device 17 and operates the respective operating bodies (the lower traveling body 2, the upper turning body 3, and the working device 5), but the external force (downhill own weight traveling). When driven by force, turning inertia force, engine output or power regeneration motor function of the pump 14b, it can be controlled as a generator, and regenerative energy can be recovered in the power storage device 17.

  An operating device 18 such as an operating lever operated by an operator in the cab of the hybrid excavator 1 operates the motors 2m, 3m, 12 and the cylinders 6c, 7c, 8c at an operating speed corresponding to the operating amount. The motors 2m, 3m, and 12 are controlled in direction and speed through the controller 19, and the cylinders 6c, 7c, and 8c are controlled in direction and speed through the control valve 20.

  The controller 19 controls the drive power supplied from the power storage device 17 to each of the motors 2m, 3m, and 12, and when the motors 2m, 3m, and 12 are driven as generators, the generated power is stored in the power storage device. The inverter 15 and the converter 16 are controlled so as to be stored in 17.

  At this time, the traveling system for controlling the traveling motor 2m and the turning system for controlling the turning motor 3m are configured such that the regenerative braking function is used for safety stop when each of the motors 2m and 3m is driven as a generator. This is a regenerative brake safety stop use subsystem as a target system for brake safety stop use.

  On the other hand, the boom cylinder system that can recover the regeneration energy of the boom cylinder 6c through the electric motor 12 is a system that does not use the regenerative brake function for safety stop when the electric motor 12 is driven as a generator. It is a subsystem.

  That is, the pump 14b has a power regeneration motor function, and the boom cylinder 6c is caused by the check valve 20a provided between the control valve 20 and the hydraulic oil tank. By supplying the return oil discharged from the head side (lower end side) to the suction side of the pump 14b, the pump 14b functions as a hydraulic motor, and the motor 12 is driven as a generator via the power transmission device 13 and the like. Therefore, it is possible to recover the regenerated energy, but it is not necessary to use the regenerative braking function of the electric motor 12 for a safe stop.

  As shown by the dotted line in FIG. 2, the state detection drawn from the motors 2 m, 3 m, 12, inverter 15, converter 16, bus between inverter 15 and converter 16, power storage device 17, controller 18, controller 19, etc. The line is connected to the failure sign determination circuit 21. This failure symptom determination circuit 21 determines the precursor state before failure of the regenerative braking function when used as a power running function of the motors 2m, 3m, and 12 and a generator.

  The failure sign determination circuit 21 is connected to a function deterioration suppression / recovery processing circuit 22. This function reduction suppression / recovery processing circuit 22 suppresses and reduces the supply / recovery power of the motors 2m, 3m, and 12 by determining the precursor state before the failure by the failure precursor determination circuit 21, thereby reducing the power running side function and regenerative braking of the motor. It suppresses and restores functional degradation. That is, in order to restore the failure sign state, the operating speed or acceleration / deceleration of the operating body (the lower traveling body 2, the upper turning body 3, and the work device 5) is forcibly reduced even when a large operation signal is input.

  Next, the circuit configuration of the failure sign determination circuit 21 and the function deterioration suppression / recovery processing circuit 22 will be described with reference to FIG.

  The failure sign determination circuit 21 includes an electric motor / inverter temperature sensor 23 for detecting the temperature of at least one of the electric motors 2m, 3m, and 12 and the inverter 15 that controls the electric motors 2m, 3m, and 12, and the electric motor / inverter temperature sensor. An unexpected temperature rise discriminating means 21a is provided by an unexpected temperature rise discriminator 24 that discriminates a state in which the temperature detected by 23 has unexpectedly increased.

  The unexpected temperature rise discriminator 24 discriminates whether or not the temperature detected by the motor / inverter temperature sensor 23 has deviated beyond the set upper temperature limit, and the detected temperature is set to the set temperature. When it is determined that the upper limit is exceeded, an ON signal “1” is output.

  Further, the operating speed (traveling speed, turning speed, boom speed, etc.) or the motor operating speed of the operating body (lower traveling body 2, upper turning body 3, working device 5) operated by the electric motors 2m, 3m, 12 is detected. A speed detector 25, a speed comparison circuit 26 for comparing the operating speed detected by the speed detector 25 with a command speed commanded by an operation signal from the operation device 18, and output from the speed comparison circuit 26 An unexpected speed deviation discriminating means 21b is provided by an unexpected speed deviation discriminator 27 that discriminates whether or not the speed deviation between the operating speed and the command speed is within a predetermined allowable range.

  The speed detector 25 shown in FIG. 2 is an angle sensor or a cylinder flow rate sensor that detects an angle change of the working device 5 that is the final load of the electric motor 12, and detects a lowering speed of the boom 6 by these sensors. To do.

  The unexpected speed deviation discriminator 27 outputs an ON signal “1” when it is determined that the speed deviation calculated by the speed comparison circuit 26 deviates from a predetermined allowable range.

  Further, the control signal comparison circuit 28 that compares the operation signal from the operation device 18 with the control signal output from the controller 19, and the deviation of the control signal from the operation signal calculated by the comparison in the control signal comparison circuit 28 That is, an unexpected control signal deviation discriminating means 21c is provided by an unexpected control signal deviation discriminator 29 that discriminates whether or not the control signal deviation is within a predetermined allowable range.

  The unexpected control signal deviation discriminator 29 outputs an ON signal “1” when it is determined that the control signal deviation calculated by the control signal comparison circuit 28 has deviated from the predetermined allowable range.

  Furthermore, a device state detector 31 that detects the state of the device that constitutes the motor 2m, 3m, 12 or the inverter 15, and a device function deterioration that determines a device function deterioration from the device state detected by the device state detector 31. The discriminator 32 is provided with device function deterioration discriminating means 21d.

  The device state detector 31 is, for example, a sensor that detects the temperature and voltage of the power storage device 17, a sensor that detects overvoltage and overcurrent of the inverter 15, and the like, which detects a deterioration state of the device function. The discriminator 32 outputs an ON signal “1” when it is discriminated that the device function detected by the device state detector 31 has decreased to a predetermined reference value.

  Further, the function deterioration is suppressed and restored by an ON signal “1” from at least one of the unexpected temperature rise determining means 21a, the unexpected speed deviation determining means 21b, the unexpected control signal deviation determining means 21c, and the equipment function deterioration determining means 21d. A first OR circuit 33 for outputting an ON signal “1” to the processing circuit 22 is provided.

  The failure sign determination circuit 21 includes a bus voltage detector 34 that detects a bus voltage V between the power storage device 17 and the motors 2m, 3m, and 12, and a bus voltage V detected by the bus voltage detector 34. An unforeseen voltage drop discriminator 35 for discriminating an unexpected drop in voltage and an unexpected voltage rise discriminator 36 for discriminating an unexpected rise in the bus voltage V detected by the bus voltage detector 34. An unexpected bus voltage discrimination means 21e for discriminating an unexpected drop and rise is provided.

  The unexpected voltage drop discriminator 35 outputs an ON signal “1” when the bus voltage V drops below the set range, and the unexpected voltage rise discriminator 36 when the bus voltage V rises above the set range. An ON signal “1” is output to.

  Note that the power storage device 17 side generally performs bus voltage deviation correction control. When the voltage fluctuation is not expected, the control of the operating body power is further performed. The voltage drop occurs when the power supply inverter supply power is larger than the power storage device supply power and when the regenerative inverter reception power is smaller than the power storage device reception power. Further, the voltage rise occurs when the power supply inverter supply power is smaller than the power storage device supply power and when the regeneration inverter reception power is larger than the power storage device reception power.

  Further, a storage state detector 37 that detects a storage state SOC (abbreviation of State Of Charge, indicated by 0 to 100%) of the power storage device 17, and an assumption of the storage state SOC detected by the storage state detector 37 Assumption of storage state SOC by SOC unexpected decrease determination unit 38 for determining an outside decrease and SOC unexpected increase determination unit 39 for determining an unintended increase in the storage state SOC detected by the storage state detector 37 Unexpected storage state determination means 21f for determining outside decrease and rise is provided.

  The SOC unexpected decrease determination unit 38 outputs an ON signal “1” when the storage state SOC decreases below the set range, and the SOC unexpected increase determination unit 39 outputs when the storage state SOC increases beyond the set range. An ON signal “1” is output to.

  Furthermore, the function deterioration is suppressed and reduced by an ON signal “1” from at least one of the unexpected voltage drop discriminator 35 of the unexpected bus voltage discriminating means 21e and the SOC unexpected voltage drop discriminator 38 of the unexpected power storage state discriminating means 21f. A second OR circuit 41 that outputs an ON signal “1” to the recovery processing circuit 22 is provided. In addition, the function degradation is suppressed and reduced by an on signal “1” from at least one of the unexpected voltage rise discriminator 36 of the unexpected bus voltage discriminating means 21e and the unexpected SOC rise discriminator 39 of the unexpected power storage state discriminating means 21f. A third OR circuit 42 for outputting an ON signal “1” to the recovery processing circuit 22 is provided.

  In addition, the failure sign determination circuit 21 is provided with a sign phenomenon display / storage device 43 that displays and stores a sign phenomenon before the failure of the regenerative braking function of the electric motors 2m, 3m, and 12. This precursor phenomenon display / memory unit 43 generates an unexpected increase in the motor / inverter temperature output from the unexpected temperature rise discriminator 24, an unexpected speed deviation output from the unexpected speed deviation discriminator 27, Generation of an unexpected control signal deviation output from the unexpected control signal deviation discriminator 29, functional degradation of the equipment output from the equipment functional degradation discriminator 32, bus voltage V output from the unexpected voltage degradation discriminator 35 Unexpected voltage drop, unexpected increase in bus voltage V output from the unexpected voltage rise discriminator 36, unexpected decrease in storage state SOC output from the SOC unexpected voltage drop discriminator 38, unexpected rise in SOC An unexpected increase in the state of charge SOC output from the discriminator 39 is individually displayed and stored.

  Next, the function deterioration suppression / recovery processing circuit 22 includes a first power control signal suppression circuit 44 connected to the first OR circuit 33 and a second power control signal connected to the second OR circuit 41. Suppression circuit 45, a third power control signal suppression circuit 46 connected to the third OR circuit 42, and an actuator as an operating body power suppression circuit connected to these power control signal suppression circuits 44, 45, 46 A supply / recovery power limiter circuit 47 is provided.

  The first power control signal suppression circuit 44 receives the ON signal from the first OR circuit 33 and operates on the power running side and the regeneration side of the operating body (the lower traveling body 2, the upper swing body 3, and the work device 5). Alternatively, a signal for suppressing the power control signal for controlling the acceleration / deceleration is output, and the second power control signal suppressing circuit 45 receives the ON signal from the second OR circuit 41 and operates on the power running side of the operating body. The third power control signal suppression circuit 46 receives the ON signal from the third OR circuit 42 and outputs a signal for suppressing the power control signal for controlling the speed or acceleration / deceleration. A signal for suppressing a power control signal for controlling the operation speed or acceleration / deceleration of the motor is output.

  Between the second power control signal suppression circuit 45 and the third power control signal suppression circuit 46, the regenerative brake use target system uses a regenerative brake safety stop use system such as a turning system for controlling the turning motor 3m. In the case of a subsystem, when the operation speed (such as turning speed) or acceleration / deceleration on the regeneration side is to be suppressed, a condition is set to suppress the power running side of the same subsystem before the regeneration side. For example, when the turning operation of the upper swing body 3 is decelerated or stopped, the driving of the motor 3m is suppressed and the operation speed is reduced, and then the regenerative brake suppression function of the motor 3m is controlled.

  The actuator supply / recovery power limiter circuit 47 receives the signals output from the power control signal suppression circuits 44, 45, 46, and operates the operating speed of the operating body (the lower traveling body 2, the upper swing body 3, and the work device 5) or Actuator power suppression signal that suppresses acceleration / deceleration is output separately for powering / regeneration side, and powering side operation body power suppression signal is output, and regenerative brake safety stop use target system speed On the condition that the operating speed of the operating body is reduced and the operating body is reduced, a regeneration-side operating body power suppression signal is output.

  Upon receiving the power running side / regenerative side actuation body power suppression signal output from the actuator supply / recovery power limiter circuit 47, the controller 19 controls the controlled speed and power (boom system) according to the actuation body. ) Or a controlled torque control command is output. At this time, the operation signal is also suppressed accordingly.

  As described above, in the device that drives / stops the actuating body (the lower traveling body 2, the upper swing body 3, and the working device 5) by the power running / regeneration of the electric motors 2m, 3m, 12, the regenerative braking function has a failure (degraded function, If you continue to drive even after the warning of (departure of use range) appears, this warning condition will worsen further and the regenerative braking function will decline, and eventually it will become a fault condition that disables driving. In addition, a regenerative brake is detected by forcibly reducing the operating speed or acceleration / deceleration of the operating body (the lower traveling body 2, the upper turning body 3, and the work device 5) even when a large operation signal is input by detecting a failure sign. It suppresses the decline in function and restores the pre-failure state.

  The precursor state before the failure of the regenerative braking function includes an unexpected rise in the temperature of the motor 2m, 3m, 12 or inverter 15 and an unexpected fluctuation in the bus voltage V (decrease in battery capacity, decline in equipment function, range of use) For example, an unexpected increase in the state of charge SOC of the power storage device 17 such as a battery, that is, a sign of a decrease in the power reception function during braking, an unexpected speed deviation, an unexpected control signal deviation, and the like. Many of these can also be used as precursors before failure of the drive function. In addition, it is possible to detect an unexpected decrease in the state of charge SOC, that is, a precursor state of power supply function deterioration during driving, and other signs can also be applied as a precursor to drive / brake function deterioration. It can also be used as a device for discriminating, suppressing, and restoring a pre-failure state.

  Next, an example of the failure prevention function of the power running function and the regenerative brake function will be described with reference to the flowchart shown in FIG.

(Step S1)
The unexpected temperature rise discriminator 24 discriminates whether or not the temperature of the electric motors 2m, 3m, 12 detected by the electric motor / inverter temperature sensor 23 or their inverters 15 has increased unexpectedly greater than a set value.

(Step S2)
The unexpected speed deviation discriminator 27 discriminates whether or not the speed deviation between the actual operating speed output from the speed comparison circuit 26 and the command speed from the operating device 18 is outside the assumption beyond a predetermined allowable range. .

(Step S3)
The unexpected control signal deviation discriminator 29 discriminates whether or not the deviation of the control signal with respect to the operation signal calculated by the comparison in the control signal comparison circuit 28, that is, the control signal deviation is larger than a predetermined allowable range. .

(Step S4)
The device function deterioration discriminator 32 discriminates those function deteriorations from the device states of the power storage device 17, the electric motors 2m, 3m, 12 or the inverter 15 detected by the device state detector 31.

(Step S5)
If the temperature of the motors 2m, 3m, 12 or their inverter 15 rises unexpectedly in step S1, or if the speed deviation between the operating speed and the command speed deviates from the predetermined allowable range in step S2, If the control signal deviation deviates from the predetermined allowable range, or if the function of the device has deteriorated in step S4, the first power control signal suppression circuit 44 receives the ON signal from the first OR circuit 33. In response to this, it outputs a signal for suppressing a power control signal for controlling the operating speed or acceleration / deceleration on the power running side and the regeneration side of the operating body (the lower traveling body 2, the upper swing body 3, and the work device 5), and the actuator is supplied.・ The recovery power limiter circuit 47 outputs the actuator power suppression signal to the controller 19 by distinguishing between the power running and regeneration side, and even if a large operation signal is input from the controller 18 to the controller 19, it is output from the controller 19. Actuator By applying a suppression signal to control the speed or acceleration, effector (lower traveling body 2, upper revolving structure 3, the working device 5) forcibly lowering the operating speed or acceleration of the.

(Step S6)
The unexpected voltage drop discriminator 35 discriminates whether or not the bus voltage V detected by the bus voltage detector 34 has fallen outside the expected lower limit value.

(Step S7)
The unexpected voltage rise discriminator 36 determines whether or not the bus voltage V has risen beyond the upper limit value.

(Step S8)
The SOC unexpected decrease determination unit 38 determines whether or not the storage state SOC detected by the storage state detector 37 has decreased to a lower limit than expected.

(Step S9)
The SOC unexpected increase determiner 39 determines whether or not the state of charge SOC has increased beyond the upper limit.

(Step S10)
When the unexpected voltage drop discriminator 35 determines that the bus voltage V has fallen below the lower limit, or the SOC unexpected drop discriminator 38 determines that the storage state SOC has fallen below the lower limit, The second power control signal suppression circuit 45 receives the ON signal from the second OR circuit 41 and outputs a signal for suppressing the power control signal for controlling the operation speed or acceleration / deceleration on the power running side of the operating body.

(Step S11)
When it is determined by the unexpected voltage rise discriminator 36 that the bus voltage V has risen from the upper limit value or when the SOC unexpected rise discriminator 39 has discriminated that the state of charge SOC has risen from the upper limit value, the third The power control signal suppression circuit 46 receives the ON signal from the third OR circuit 42 and outputs a signal for suppressing the operation speed or acceleration / deceleration on the regeneration side of the operating body.

  Next, an example in which the regeneration-side operating body speed or acceleration / deceleration is suppressed and controlled will be described with reference to the flowchart shown in FIG.

(Step S12)
The controlled system is a regenerative brake safety stop use subsystem that uses the regenerative brake safety stop function (for example, a swing system of a hydraulic excavator), or a regenerative brake safety stop non-use system that does not use the regenerative brake safety stop function It is determined whether it is a subsystem (for example, a boom cylinder system of a hydraulic excavator). In the regenerative brake safety stop use subsystem, it is necessary to prevent the operating body such as the upper swing body 3 from losing the safety stop function due to the suppression of the regenerative brake function.

(Step S13)
In order to avoid losing the safety stop function due to the suppression of the regenerative brake function, it is first determined whether or not the power running side speed of the regenerative brake safety stop use subsystem has been suppressed.

(Step S14)
Further, it is determined whether or not the operating speed of the operating body such as the upper swing body 3 has decreased.

(Step S15)
If YES in step S13 and step S14, since it has been confirmed that the regenerative brake circuit has no problem in terms of safety stop, the controller 19 outputs a signal for suppressing the operating speed or acceleration / deceleration of the operating body by the regenerative brake function. .

  For example, when the power running side speed (driving speed) of the upper swing body 3 is suppressed and the operating speed of the upper swing body 3 is reduced, the motor 3m is controlled as a generator, and the regenerative energy generated by the motor 3m is controlled. Is collected in the power storage device 17. At this time, the controller 19 controls the inverter 15 and the converter 16 so as to suppress the deceleration torque of the upper swing body 3 with respect to the regenerative braking function of the electric motor 3m.

(Step S16)
When NO in step S13 and step S14, it cannot be confirmed that there is no problem even if the regenerative brake is operated, so avoid power suppression by the regenerative brake function in the regenerative brake safety stop use subsystem such as a turning system. Only regenerative speed or acceleration / deceleration control signals are suppressed in subsystems that do not use regenerative brake safety stop, such as boom cylinder systems that do not use regenerative brake for safe stop.

  For example, when the boom 6 as the operating body is rotated downward by the load of the work device 5, hydraulic oil discharged from the head side of the boom cylinder 6c is pressurized and supplied to the suction side of the pump 14b through the control valve 20, The hydraulic oil energy causes the pump 14b to operate as a hydraulic motor, and the electric motor 12 is driven as a generator via the power transmission device 13 by the hydraulic motor function of the pump 14b. The regenerative energy generated by the electric motor 12 is stored in the power storage device 17. Is done.

  Since the boom control system does not use the regenerative brake for safety stop, the power control signal of the electric motor 12 at this time has no problem even if the regenerative brake function is suppressed, so when the suppression signal is input, the controller 19 The inverter 15 and the converter 16 are controlled so as to suppress the recovered power.

  In this way, among the multiple subsystems that perform power running and regeneration (boom cylinder system, turning system, etc. in the case of hydraulic excavators), the subsystem that uses regeneration as a safety stop brake (turning system) When suppressing the speed or acceleration / deceleration by regenerative braking, it is necessary to confirm that there is no problem in terms of safety stop. When unconfirmed, speed control by regenerative braking is not performed. The condition that there is no problem in the safety stop is that the power running side speed of the regenerative brake safety stop use subsystem is previously suppressed, the operating speed is reduced, and the like.

  Next, the effect of this embodiment will be described.

  The failure sign detection circuit 21 and the function deterioration suppression / recovery processing circuit 22 determine the precursor state before the failure of the regenerative braking function and power running side function of the electric motors 2m, 3m, and 12 of the hybrid work machine. , 3m, 12 drive speed or acceleration / deceleration can be reduced to suppress and restore the regenerative braking function and power running side function of the motor 2m, 3m, 12, so that the electric motor of the hybrid hydraulic excavator 1 It is possible to prevent the 2m, 3m, and 12 regenerative braking functions and the power running function from failing. In particular, it is possible to prevent the regenerative braking function from being damaged and the safety stop function from being impaired.

  In addition, since the operation exceeding the usage conditions of the motors 2m, 3m, and 12 can be dealt with, it is possible to avoid an unnecessary increase in the equipment capacity due to the widening of the usage conditions. As a result, it is possible to actively work on energy recovery by regenerative braking and efficiency improvement thereby.

  Unexpected temperature rise determining means 21a, unexpected speed deviation determining means 21b, unexpected control signal deviation determining means 21c, equipment function deterioration determining means 21d and OR circuit 33, and motors 2m, 3m, 12 and their inverter 15 are not expected Regenerative braking function for any of the following: temperature rise, actuating body (lower traveling body 2, upper turning body 3, work device 5) unexpected speed deviation, controller 19 unexpected control signal deviation and equipment function degradation Even if the power running side function is degraded, it can be expected to be suppressed and restored, preventing the regenerative braking function and the power running function of the motors 2m, 3m, and 12 from being damaged. it can.

  The unexpected bus voltage determination means 21e and the unexpected storage condition determination means 21f can distinguish the failure sign on the power running side from the failure sign on the regeneration side by the unexpected decrease and increase in the bus voltage V and the storage state SOC. Therefore, it is possible to easily cope with suppression / recovery processing of functional degradation.

  Since the cause of the failure precursor phenomenon is displayed and stored in the precursor phenomenon display / memory unit 43, the display / memory content can be used for investigation and can be easily dealt with by maintenance.

  Actuator power suppression signal is output from actuator supply / recovery power limiter circuit 47 on condition that the power running side acceleration speed or acceleration / deceleration of the regenerative brake safety stop use subsystem is suppressed and the operating speed is reduced. Since it outputs, when stopping an operation body, it can prevent that a safe stop function may be impaired by suppression of a regenerative brake function.

  The temperature rise is caused not only by regeneration but also by excessive power on the power running side, and if this progresses, a regenerative brake failure will occur, so the actuator supply / recovery power limiter circuit 47 suppresses both the power running side and the regeneration side actuator power. To do.

  At that time, there is no particular restriction on the power control on the power running side, but the power control on the regeneration side suppresses confirmation that there is no problem with safety stop even if the regenerative braking function of the safety stop system is suppressed. First, confirm that there is no problem even if the regenerative brake function is suppressed if the power running side operating speed of the regenerative brake safety stop use target system is suppressed and the operating speed is reduced. As a result, the actuator supply / recovery power limiter 47 outputs a regeneration-side actuation body power suppression signal. For example, when stopping an actuation body (such as the upper swing body 3) that is operating at high speed, It is possible to prevent the possibility of losing the function of performing a safe stop due to the suppression.

  The regenerative brake function suppression / recovery process alleviates temperature rise, overdischarge / overcharge of the power storage device 17, and the recovery brake function can be recovered.

  As described above, by incorporating the warning detection / determination function for failure (deterioration of function, deviation of driving range) into the regenerative brake device, it is possible to prevent the regenerative brake function from failing and improve driving continuity and reliability.

  In other words, it is not an equipment failure, operation outside the operating conditions, storage state SOC deviation outside the operating range of the SOC, etc., by lowering the control speed or acceleration / deceleration, temperature rise and bus voltage fluctuation can be suppressed, the storage state Since the SOC can also be restored (since the restoration function is incorporated), it leads to improved continuity of operation and improved reliability.

  The actuator hydraulic drive type does not have a regenerative braking function, and the hydraulic equipment is a mechanical braking system with a proven track record. Therefore, no special device like this system is provided. When this is changed to an electric drive type, it is essential to ensure the safety stop function and to improve the reliability, and this method is an effective method. In addition, this method is a versatile method that does not require a special sensor or the like for implementation.

  By providing this function, the usage conditions of the equipment can be limited to a certain range, and a safe stop can be secured even during operation outside the usage conditions, so there is no need to increase the equipment capacity by unnecessarily tightening the usage conditions. The capacity can be set within a reasonable range.

  In the above embodiment, the example applied to the hydraulic drive and electric drive hybrid hydraulic excavator 1 has been described. However, the present invention can also be applied to an electric drive work machine that does not use hydraulic pressure.

It is a block diagram which shows one Embodiment of the regeneration and power running function failure prevention apparatus which concerns on this invention. It is a circuit diagram which shows the system configuration | structure of a failure prevention apparatus same as the above. It is a flowchart which shows the control method of a failure prevention apparatus same as the above. It is a flowchart which shows suppression control of the operating body power of a failure prevention apparatus same as the above.

Explanation of symbols

1 Hybrid hydraulic excavator as a hybrid work machine 2 Undercarriage as an operating body
2m, 3m, 12 Electric motor 3 Upper swing body as operating body 5 Working device as operating body
15 Inverter
17 Power storage device
21 Predictive failure detection circuit
21a Means to detect unexpected temperature rise
21b Means for discriminating unexpected speed deviation
21d Device function degradation judgment means
21e Unexpected bus voltage discrimination means
21f Unexpected storage state determination means
22 Functional degradation suppression / recovery processing circuit
33 OR circuit
43 Precursor display / memory
47 Actuator Supply / Recovery Power Limiter Circuit as Actuator Power Suppression Circuit

Claims (6)

An electric motor having a regenerative braking function and operating an operating body;
A failure sign determination circuit for determining the precursor state before failure of the regenerative braking function when used as a power running function and a generator of the motor;
A function deterioration suppression / recovery processing circuit that suppresses and restores the power running side function and regenerative braking function of the motor by reducing the supply / recovery power of the motor by determining the precursor state before the failure by this failure sign determination circuit A regenerative / power running function failure prevention device characterized by comprising: The failure sign detection circuit
An unexpected temperature rise determining means for detecting a temperature of at least one of the electric motor and an inverter for controlling the electric motor, and determining a state in which the temperature has increased unexpectedly;
An unexpected speed deviation discriminating means for detecting an operating speed of the operating body operated by the electric motor or an electric motor operating speed, and discriminating a state in which the speed deviation between the operating speed and the command speed commanded by the operation signal is not assumed; ,
A device function lowering determination means for detecting a state of the device constituting the electric motor and the inverter and determining a function deterioration of the device;
An OR circuit that outputs an ON signal to the function deterioration suppression / recovery processing circuit in response to an ON signal from at least one of an unexpected temperature rise determination means, an unexpected speed deviation determination means, and an equipment function deterioration determination means. The regenerative / power running function failure prevention device according to claim 1. A power storage device that stores electric power generated from an electric motor that functions as a generator,
The failure sign detection circuit
An unexpected bus voltage determination means for detecting a bus voltage between the power storage device and the electric motor to determine an unexpected decrease and increase in the bus voltage;
The regenerative / power running function failure prevention device according to claim 1 or 2, further comprising: an unexpected storage state determination unit that detects a storage state of the storage device and determines an unexpected decrease and increase in the storage state. . The regeneration / power running function failure prevention device according to any one of claims 1 to 3, wherein the failure symptom determination circuit includes a phenomenon display / storage device for displaying and storing a symptom phenomenon. The function deterioration suppression / recovery processing circuit includes an operating body power suppression circuit that outputs an operating body power suppression signal that suppresses the operating speed or acceleration / deceleration of the operating body,
The operating body power suppression circuit outputs a powering side operating body power suppression signal, the power running side speed of the regenerative brake safety stop use target system is suppressed, and the operating body operating speed is reduced. The regeneration / power running function failure prevention device according to any one of claims 1 to 4, wherein a regeneration-side actuation body power suppression signal is output. The regenerative / power running function failure prevention device according to any one of claims 1 to 5, wherein the device is applied to an electric motor of a hybrid work machine.

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