JP7432033B2 - crane - Google Patents

Description

The present invention relates to cranes and power electronic equipment.

1. In working machines such as cranes, an AC power source, an AC motor, and a storage battery are interconnected via a DC bus (for example, Patent Document 1). The AC power source is connected to a DC bus via a converter device that converts AC power into DC power. The storage battery is connected to a DC bus via a charge/discharge controller that controls the timing and amount of power for charging and discharging the storage battery. The AC motor is connected to a DC bus via an inverter that converts DC power to AC power.

Japanese Patent Application Publication No. 2006-131311 Japanese Patent Application Publication No. 2007-295699 Japanese Patent Application Publication No. 2005-116485

1. Power electronics equipment is used to make hybrid cranes. The power electronics equipment mainly consists of a capacitor and a converter, and is connected to the crane's DC bus. When the crane is activated, the power electronics equipment is also activated. When electrically connecting the DC bus and the capacitor, it is desirable to use power electronics equipment that is highly reliable in terms of safety.

2. FIG. 1 is a block diagram of a conventional power electronics device. The power electronics device 100R includes a motor 102, a converter device 110, and a load drive device 120, which are loads. Converter device 110 boosts DC voltage V _E from DC power source 104 such as a battery to generate DC link voltage V _DC , and supplies it to load drive device 120 via DC link 130 . Load drive device 120 is, for example, a motor drive device, and includes an inverter 122 that drives motor 102, which is a load. A large capacity DC link capacitor 132 is connected to the DC link 130. A large-capacity smoothing capacitor 124 is also connected to the input of the inverter 122.

When the power electronics device 100R is started, the charges on the DC link capacitor 132 and the smoothing capacitor 124 are zero. When a DC voltage _VE is applied to such a capacitor, an inrush current flows. To prevent this, charging resistor R _J , relay RY1, and electromagnetic contactor MC1 are provided. First, relay RY1 is turned on, and DC link capacitor 132 is slowly charged via charging resistor _RJ and diode D11. Further, the smoothing capacitor 124 is slowly charged via the charging resistor R2.

When the charging of the DC link capacitor 132 and the smoothing capacitor 124 progresses to a certain extent, or when their charging is completed, the magnetic contactors MC1 and MC2 are turned on.

Since relays and electromagnetic contactors (hereinafter collectively referred to as switches) have mechanical contacts, they deteriorate over time due to oxidation and wear.

In the power electronics device 100R of FIG. 1, deterioration over time especially of the relay RY1 and the electromagnetic contactor MC1 becomes a problem. Therefore, components with auxiliary contacts are generally used for these switches, and failure detection (welding and open detection) using answerback signals is widely performed.

FIG. 2 is a block diagram of a conventional power electronics device. The power electronics device 100S in FIG. 2 further includes a redundant switch RY2 on the negative pole (N pole) side instead of using a switch without an auxiliary contact. Then, the switch RY1 (MC1) on the positive side and the switch RY2 on the negative side are made conductive or cut off in order, and when the voltage or current in each state deviates from the expected normal value, it is determined that there is an abnormality.

A switch with an auxiliary contact used in the power electronics device 100R of FIG. 1 is generally expensive and often large, which may cause problems in its adoption.

Furthermore, in the power electronics device 100S of FIG. 2, it is necessary to add a redundant switch RY2, which increases the size and cost of the power electronics device 100S.

The present invention has been made under such circumstances, and one exemplary object of the present invention is to provide a crane equipped with power electronics equipment that is safer at startup, and a power electronics equipment mounted on this crane. It is to provide. Another exemplary object of the embodiment is to provide a power electronics device capable of detecting deterioration of a switch.

One aspect of the present invention relates to a crane. The crane includes a main body, a lifting section, a traveling section, a driving section that drives the lifting section, and a power storage system that supplies power to the driving section. The crane has a function of diagnosing an abnormality in the power storage system at the time of startup or termination.

2. Certain embodiments of the present invention relate to power electronics equipment. Power electronics equipment includes an inrush current prevention circuit that includes a capacitor and a switch installed between a DC power supply and the capacitor, and a cutoff command or continuity command that is given to the switch during a determination period to determine the capacitor's voltage or inrush current prevention circuit. and a determiner that detects an abnormality in the switch based on the current flowing in the circuit.

Note that arbitrary combinations of the above-mentioned constituent elements, and mutual substitution of constituent elements and expressions of the present invention among methods, devices, systems, etc., are also effective as aspects of the present invention.

According to an aspect of the present invention, it is possible to provide a crane equipped with power electronics equipment that is safer at startup, and a power electronics equipment mounted on this crane. Further, according to an aspect of the present invention, deterioration of a switch can be detected.

FIG. 1 is a block diagram of a conventional power electronics device. FIG. 1 is a block diagram of a conventional power electronics device. FIG. 1 is a block diagram of an electronic device according to an embodiment. FIG. 3 is a diagram illustrating abnormality detection by a determiner. FIG. 3 is a diagram illustrating abnormality detection by a determiner. FIG. 3 is a block diagram showing a power electronics device according to a modified example. 7A and 7B are a schematic front view and a schematic side view, respectively, of the crane system according to this embodiment. FIG. 8 is a power system diagram of the crane system.

(Summary of embodiment)
One embodiment disclosed herein relates to a crane. The crane includes a main body, a lifting section, a traveling section, and a driving section that drives the lifting section, and a power storage system that supplies power to the driving section. The crane has a function of diagnosing an abnormality in the power storage system at the time of startup or termination.

The crane may include an abnormality notification unit that detects an abnormality and notifies the existence of the abnormality at the time of startup, or detects the abnormality and notifies the existence of the abnormality at the time of termination.

In the case of remote operation, the abnormality alarm unit sends a notification to the notification means provided in the remote control means, in the case of automatic operation, to the notification means provided in the administration building via the communication means, and in the case of manual operation, to the notification means provided in the control building. The abnormality may be notified to a notification means provided indoors.

The abnormality notification unit may change the notification content depending on the type of abnormality. In the case of an abnormality at a level that restricts work, a predetermined first level abnormality is notified and replacement or maintenance is recommended. However, if an abnormality occurs at a level that does not restrict work, a predetermined first level abnormality is notified. A low-level second-level abnormality may be notified.

In a state where it is determined that an abnormality has occurred and the abnormality is notified or work is restricted, work may be started in a work mode that does not utilize the power storage system by performing a predetermined mode change operation.

In the work mode that does not utilize the power storage system, at least one of the traveling speed and the operating speed of the hanging section may be limited.

One embodiment disclosed herein relates to power electronics equipment. Power electronics equipment includes an inrush current prevention circuit that includes a capacitor and a switch installed between a DC power supply and the capacitor, and a cutoff command or continuity command that is given to the switch during a determination period to determine the capacitor's voltage or inrush current prevention circuit. and a determiner that detects an abnormality in the switch based on the current flowing in the circuit. According to this embodiment, deterioration of a switch can be detected without using a switch with an auxiliary contact or a redundant switch. Furthermore, the cost of power electronics equipment can be reduced.

During the charging period in which a conduction command is given to the switch to charge the capacitor, the determination device temporarily gives a cut-off command to the switch and determines whether there is an abnormality based on the change in the current flowing through the inrush current prevention circuit at that time. You may. If the switch is normally shut off while a shutoff command is given to the switch, the current will be zero. On the other hand, if the switch has deteriorated such as welding, the current will continue to flow. Therefore, it is possible to determine whether the switch is abnormal based on the current state of the switch (conduction/cutoff) and changes in current.

The determiner may temporarily issue a cutoff command to the switch during a charging period in which a conduction command is given to the switch to charge the capacitor, and determine whether there is an abnormality based on the change in the voltage of the capacitor at that time. . If the switch is normally shut off while a shutoff command is given to the switch, charging to the capacitor will stop and the voltage will change to zero. On the other hand, if the switch has deteriorated such as welding, the charging current continues to flow into the capacitor, so the voltage across the capacitor continues to increase. Therefore, it is possible to determine whether the switch is abnormal based on the current state of the switch (conduction/cutoff) and the voltage change of the capacitor.

The power electronics device may further include a converter device provided between the inrush current prevention circuit and the capacitor. The converter device may be subjected to a switching operation while a cutoff command is given to the switch, and the presence or absence of an abnormality may be determined based on the current flowing through the rush current prevention circuit at that time.

If the switch is normally shut off in a state where a shutoff command is given to the switch, no current flows through the inrush current prevention circuit even if the converter device performs a switching operation. On the other hand, if the switch has deteriorated such as welding, current will flow through the inrush current prevention circuit. Therefore, the presence or absence of an abnormality can be determined based on the current.

The power electronics device may further include a converter device provided between the inrush current prevention circuit and the capacitor. The converter device may be subjected to a switching operation while a cutoff command is given to the switch, and the presence or absence of an abnormality may be determined based on the voltage of the capacitor at that time.

If the switch is normally shut off when a shutoff command is given to the switch, the current flowing through the rush current prevention circuit will be zero even if the converter device performs a switching operation, and therefore the voltage of the capacitor will not rise. On the other hand, if the switch has deteriorated such as welding, current will flow through the inrush current prevention circuit, causing the voltage of the capacitor to rise. Therefore, the presence or absence of an abnormality can be determined based on the voltage of the capacitor.

(Embodiment)
DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on preferred embodiments with reference to the drawings. Identical or equivalent components, members, and processes shown in each drawing are designated by the same reference numerals, and redundant explanations will be omitted as appropriate. Furthermore, the embodiments are illustrative rather than limiting the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

In this specification, "a state in which member A is connected to member B" refers to not only a case where member A and member B are physically directly connected, but also a state in which member A and member B are electrically connected. This also includes cases in which they are indirectly connected via other members that do not substantially affect the connection state or impair the functions and effects achieved by their combination.

Similarly, "a state in which member C is provided between member A and member B" refers to the case where member A and member C or member B and member C are directly connected, This also includes cases in which they are indirectly connected via other members that do not substantially affect the connection state or impair the functions and effects achieved by their combination.

The vertical and horizontal axes of the waveform diagrams and time charts referred to in this specification have been enlarged or reduced as appropriate for ease of understanding, and each waveform shown has also been simplified for ease of understanding. exaggerated or emphasized.

FIG. 3 is a block diagram of an electronic device according to an embodiment. Power electronics equipment 200 includes a DC power supply 202, an inrush current prevention circuit 210, a DC link capacitor 220, and a converter device 230.

The DC power supply 202 is a battery, a capacitor, or an external converter, and generates a DC voltage (also referred to as input voltage) _VE . A DC link capacitor 220 is connected to the DC link 204 . Although not shown in FIG. 3, a load driving device as shown in FIGS. 1 and 2 is connected to the DC link 204. The type of load is not particularly limited.

Immediately after the power electronics device 200 is started, when the DC link capacitor 220 has little charge and the DC link voltage V _DC is low, when the input voltage V _E is applied to the DC link capacitor 220 via a low impedance path, an inrush current occurs. flows. To prevent this, an inrush current prevention circuit 210 is provided between the DC power supply 202 and the DC link capacitor 220.

Inrush current prevention circuit 210 includes at least one switch provided between DC power supply 202 and DC link capacitor 220. In the present embodiment, the inrush current prevention circuit 210 includes a first switch MC1, a charging resistor _RJ and a second switch RY1 provided in series in a path parallel to the first switch MC1. For example, the first switch MC1 is an electromagnetic contactor, and the second switch RY1 is a relay.

Converter device 230 is provided between inrush current prevention circuit 210 and DC link capacitor 220. In the operating state, converter device 230 boosts input voltage _VE to generate DC link voltage V _DC higher than DC voltage _VE in DC link 204 (powering operation). Controller 240 includes a converter controller 242 that controls converter device 230 . Converter controller 242 generates a control signal S _CTRL that defines the duty ratio of the gate signal of converter device 230 .

A digital feedback signal D _VDC indicating the DC link voltage V _DC is fed back to the controller 240 . The controller 240 adjusts the duty ratio by feedback so that the feedback signal D _VDC approaches a target value D _REF that defines a target voltage of the DC link voltage V _DC .

Gate driver 232 drives transistors M1 and M2 of converter device 230 based on the duty ratio indicated by control signal _SCTRL .

Current sensor 234 is, for example, a current transformer, and detects current _IL flowing through reactor L1. A digital value _{DIL indicating the current IL and} a digital value _DVE indicating the input voltage _VE are input to the controller 240. The feedback control in converter controller 242 may reflect input voltage V _E and current I _L flowing through reactor L1 of converter device 230.

When DC power supply 202 includes a rechargeable battery or capacitor, converter device 230 can be operated regeneratively, and excess energy on the DC link 204 side may be recovered to DC power supply 202.

The controller 240 has a function of controlling on/off of the switches MC1 and RY1 included in the inrush current prevention circuit 210 and detecting an abnormality of the switches MC1 and RY1.

During the charging period immediately after power electronics device 200 is started, controller 240 stops converter device 230 and turns on second switch RY1. As a result, a charging current I _CHG flows through the resistor R _J , the second switch RY1, and the diode D11, and the DC link capacitor 220 is charged.

When the DC link voltage V _DC rises to such an extent that there is no risk of inrush current to the DC link capacitor 220, the first switch MC1 is turned on. Controller 240 then starts operation of converter device 230.

Detection of an abnormality in the switch of the inrush current prevention circuit 210 will be explained. Controller 240 includes a determiner 244. The determiner 244 gives a cutoff command or a conduction command to the switches MC1 and RY1 during the determination period, and determines the command (switch usage status) and the voltage V _DC of the DC link capacitor 220 at that time or the inrush current prevention circuit 210. An abnormality in the switches MC1 and RY1 is detected based on the combination of currents.

It can be understood that the current sensor 234 detects the current (referred to as input current) _IIN flowing through the inrush current prevention circuit 210. The input current I _IN is nothing but the reactor current I _L in the operating state of the converter device 230, and is nothing but the charging current I _CHG during the charging period.

Abnormality detection by the determiner 244 will be described below with reference to three embodiments.

(First example)
FIG. 4 is a diagram illustrating abnormality detection by the determiner 244.
At time t ₀ , the controller 240 gives a conduction command to the second switch RY1 to start charging the DC link capacitor 220 . The controller 240 inserts a determination period τ _DET1 into the charging period, and temporarily (t ₁ to t ₂ ) gives a shutdown command to the second switch RY1 during the determination period τ _DET1 . The determiner 244 determines the presence or absence of an abnormality based on the change in the input current _IIN flowing through the inrush current prevention circuit during the determination period _τDET1 .

If the second switch RY1 is normally cut off while the cutoff command is given to the second switch RY1, the input current _IIN becomes zero as shown by the solid line. On the other hand, if the second switch RY1 has deteriorated such as welding, the non-zero input current _IIN continues to flow as shown by the dashed line. Therefore, the determiner 244 can determine whether the switch is abnormal based on the input current I _IN during the determination period τ _DET1 . For example, the determiner 244 may determine that the digital value DI _L in the determination period τ _DET1 is abnormal when it is higher than a predetermined threshold, and that it is normal when it is lower.

At the end time _t2 of the determination period _τDET1 , the second switch RY1 may be turned on again. Then, a conduction command may be given to the first switch MC1 at time _t3 when the DC link voltage _VDC rises to a voltage level substantially equal to the input voltage _VE and there is no longer a risk of inrush current. Thereafter, converter device 230 starts operating at time _t4 .

Note that if the DC link voltage _VDC is sufficiently high to the extent that there is no risk of inrush current at the end time _t2 of the determination period _τDET1 , the first switch MC1 is immediately turned on at time _t2 , and the first switch MC1 is turned on immediately at time t2. The DC link capacitor 220 may be charged via MC1.

(Second example)
Continuing to refer to FIG. In the second embodiment, the determiner 244 determines whether there is an abnormality based on the change in the DC link voltage V _DC during the determination period τ _DET1 . If the second switch RY1 is normally cut off while the cutoff command is given to the second switch RY1, charging to the DC link capacitor 220 will stop, so the rise in the DC link voltage V _DC will stop as shown by the solid line. However, the voltage change becomes zero. On the other hand, if the second switch RY1 has deteriorated such as welding, the charging current I _CHG continues to flow through the DC link capacitor 220, so the DC link voltage V _DC continues to increase as shown by the dashed line. Therefore, the determiner 244 can determine whether the second switch RY1 is abnormal based on the DC link voltage V _DC during the determination period τ _DET1 . For example, the determiner 244 may determine that it is normal when the amount of change in the digital value _DVD during the determination period τ _DET1 is substantially zero, and that it is abnormal when it is non-zero. More specifically, the digital value _DVD is sampled at each of the start time _t1 and end time _t2 of the determination period, and if the difference between them is larger than a predetermined threshold value, it is determined to be abnormal, and if it is smaller, it is determined to be normal. It's okay.

Next, the determination period τ _DET1 in the first embodiment or the second embodiment will be explained. For example, the determination period τ _DET1 may be set at the start time t ₁ of the determination period τ after a predetermined delay time has elapsed from the charging start time t ₀ .

Alternatively, monitor the input voltage _VE immediately after startup, multiply the input voltage _VE by a coefficient K (K<1) to determine the threshold value K x _VE , and determine when the DC link voltage _VDC has reached the threshold value. The time may be set as the start time _t1 of the determination period τ.

Alternatively, the input current I _IN during the charging period may be monitored, and the time when the input current I _IN reaches a peak and then decreases to a predetermined reference value may be set as the start time t ₁ of the determination period τ.

(Third example)
FIG. 5 is a diagram illustrating abnormality detection by the determiner 244. A determination period τ _DET2 is inserted during the non-charging period after the end of the charging period. During this determination period τ _DET2 , the controller 240 is given a command to shut off both the first switch MC1 and the second switch RY1. Then, converter device 230 is brought into operation.

For example, the determination period τ _DET2 may be inserted near time t ₃ in FIG. 4 . In this case, the DC link voltage V _DC is substantially equal to the input voltage V _E. If the switches MC1 and RY1 of the inrush current prevention circuit 210 are turned off normally when the converter device 230 is in a switching operation, the DC link voltage V _DC does not increase and remains the original voltage, as shown by the solid line. The level (here V _E ) is maintained. If an abnormality occurs in either switch MC1 or RY1, the DC link voltage _VDC increases as a result of the boost operation of converter device 230, as shown by the dashed line. Therefore, the determiner 244 can detect an abnormality in the switches MC1 and RY1 based on the amount of voltage change during the determination period _τDET2 .

For example, the determiner 244 may determine that it is normal when the amount of change in the digital value _DVD during the determination period τ _DET2 is substantially zero, and that it is abnormal when it is non-zero. More specifically, the digital value _DVD is sampled at each of the start time _t1 and end time _t2 of the determination period, and if the difference between them is larger than a predetermined threshold value, it is determined to be abnormal, and if it is smaller, it is determined to be normal. It's okay.

(Fourth example)
Continuing to refer to FIG. In the fourth embodiment, the determiner 244 determines whether there is an abnormality based on the change in the input current I _IN during the determination period τ _DET2 . If both the first switch MC1 and the second switch RY1 are normally cut off during the determination period τ _DET2 , the input current I _IN is zero as shown by the solid line. On the other hand, if an abnormality occurs in either the first switch MC1 or the second switch RY1, the input current _IIN becomes non-zero as shown by the dashed line. Therefore, the determiner 244 can determine whether the switch is abnormal based on the input current I _IN during the determination period τ _DET2 . For example, the determiner 244 may determine that the digital value DI _L in the determination period τ _DET2 is abnormal when it is higher than a predetermined threshold, and determined to be normal when it is lower.

In the third embodiment and the fourth embodiment, the determination period τ _DET2 may be inserted when the power electronics device 200 is terminated. In this case, the initial value of the DC link voltage V _DC is a high voltage after boosting.

(Modified example)
In the embodiment, the abnormality detection of the switch of the inrush current prevention circuit 210 provided upstream of the converter device 230 has been described, but the application of the present invention is not limited thereto. As shown in FIGS. 1 and 2, a rush current prevention circuit including a resistor R2 and a switch MC2 is provided at the front stage of the load driving device 120, and the present invention can also be applied to detecting an abnormality in the switch MC2. FIG. 6 is a block diagram showing a power electronics device 300 according to a modified example. DC power supply 302 includes a converter that generates a DC link voltage V _DC on DC link 304 .

Inrush current prevention circuit 310 is provided between DC power supply 302 and smoothing capacitor 320. In this modification, inrush current prevention circuit 310 includes a resistor R2 and switches MC2 and RY2. Load drive device 330 drives load 306 such as a motor based on the DC voltage generated in smoothing capacitor 320 .

The controller 340 controls the switches MC2, RY2 and the load driving device 330, and detects abnormalities in the switches MC2, RY2. As the detection method, the same method as in the first to fourth embodiments described above can be adopted.

When adopting the first and second embodiments, VE in the above description and FIG. 4 may be read _{as V DC ,} and V _DC may be read as V _IN . When adopting the third and fourth embodiments, during the determination period _τDET2 , a cutoff command is given to the switches MC2 and RY2 to operate the load driving device 330, and the change in the voltage _VIN or the current _I1 at that time is All you have to do is detect the change.

Power electronics equipment applied to industrial machinery, construction machinery, and transportation vehicles may be started in response to the startup of industrial machinery, construction machinery, and transportation vehicles, and at startup, the voltage of the capacitor is 0V, and the power electronics equipment is applied to industrial machinery, construction machinery, and transportation vehicles. The device may charge the capacitor after startup.

Note that the present invention can also be applied to power electronics equipment having a switch with an auxiliary contact or a redundant switch RY2 from the viewpoint of duplication of protection. It is understood that the effects of simple configuration, size reduction, cost reduction, etc. will be even more significant if there is no power electronics equipment.

In addition, when an abnormality is detected in power electronics equipment, the controller installed in the industrial machine, etc. is notified, the abnormality is displayed on the display section, etc. installed in the industrial machine, etc., and the industrial machine If such systems are stopped, it will contribute to improving safety. Further, preliminary or predictive notification may be provided, and in this case, it is excellent from the viewpoint of failure prediction without stopping industrial machinery, etc.

The uses of power electronics equipment are not particularly limited, but include, for example, industrial machinery such as injection molding machines and presses, construction machinery such as shovels and cranes, and transportation vehicles such as forklifts and automatic guided vehicles (in general, industrial (referred to as machines, etc.).

7A and 7B are a schematic front view and a schematic side view, respectively, of the crane system according to this embodiment. A plurality of pillars 40 support girders 41. The columns 40 and girders 41 constitute a gate-shaped frame. Wheels 42 are attached to the lower ends of the pillars 40, and the gate-shaped frame runs along rails 43. The direction perpendicular to the plane of the paper in FIG. 4A and the left-right direction in FIG. 4B correspond to the traveling direction. A trolley 45 is mounted on the girder 41. A hoist 46 is mounted on the trolley 45. The portal frame and the wheels 42 constitute the main body, and the trolley 45, the hoist 46, and the lifting section (hanging tool 47 and wire) constitute the working section.

A plurality of electric actuators drive respective actuating parts. For example, a traveling motor 51 mounted on a gate-shaped frame drives the wheels 42 . A traverse motor 52 mounted on the trolley 45 moves the trolley 45 in the traverse direction. The horizontal direction in FIG. 4A and the direction perpendicular to the plane of FIG. 4B correspond to the transverse direction. The winding machine 46 includes a winding motor 53, and winds up and lets out a wire to which a hanging device 47 such as a hook is attached to the tip. In this way, the electric actuators such as the hoisting motor 53, the traversing motor 52, and the traveling motor 51 operate the hanging tool 47, the trolley 45, and the wheels 42, respectively.

An AC power source 60, a power converter (DC-DC converter) 65, a power storage device 67, and a power converter (DC-DC converter) 68 are mounted on the gate-shaped frame. AC power supply 60 includes an engine 61 and a generator 62. The AC power supply 60 supplies driving power to the hoisting motor 53, the traversing motor 52, and the traveling motor 51. Furthermore, power storage device 67 is charged by power supplied from AC power supply 60 .

A power conversion device 68 and a power storage device (power storage device) 67 are attached to a DC bus 70 (DC bus) as a power storage system (power electronics device) 90. It can also be retrofitted to a crane that is not equipped with such a power storage system (power electronics device) 90.

FIG. 8 is a power system diagram of the crane system. An AC power source 60 is connected to a DC bus 70 via a rectifier 63 and a power converter 65. The power conversion device 65 converts the DC power output from the AC power supply 60 and rectified by the rectifier 63 into DC power of a target voltage, and supplies the DC power to the DC bus 70 . A smoothing capacitor 72 is connected between the positive side bus 70P and the negative side bus 70N of the DC bus 70.

A power storage device 67 is connected to a DC bus 70 via a power conversion device 68. Power conversion device 68 controls charging and discharging of power storage device 67. When power storage device 67 is discharged, power conversion device 68 boosts the output voltage of power storage device 67 and supplies power from power storage device 67 to DC bus 70 . When charging power storage device 67 , power conversion device 68 steps down the voltage of DC bus 70 and supplies power from DC bus 70 to power storage device 67 .

A running motor 51 is connected to a DC bus 70 via an inverter 54 and a power converter (DC-DC converter) 57. A traverse motor 52 is connected to a DC bus 70 via an inverter 55 and a power converter (DC-DC converter) 58. A hoisting motor 53 is connected to a DC bus 70 via an inverter 56 and a power converter (DC-DC converter) 59. Power converters 57, 58, and 59 boost the voltage of DC bus 70, respectively, and supply the boosted power to inverters 54, 55, and 56.

The controller 80 controls the power converters 57 , 58 , 59 , 65 , 68 and the inverters 54 , 55 , 56 to supply power from the DC bus 70 to the traveling motor 51 , the traversing motor 52 , and the hoisting motor 53 . supply. Controller 80 controls power converters 57, 58, 59, 65, and 68 to maintain the voltage of DC bus 70 at a preset target value. When the hoisting motor 53 performs a lowering operation, the controller 80 controls the inverter 56 and the power converter 59 to step down the regenerative power generated by the hoisting motor 53 and supply it to the DC bus 70 . Power storage device 67 can be charged with this regenerated power.

A rush current prevention circuit 76A is provided between the power conversion device 68 and the power storage device 67.

The controller 80 has a function of diagnosing an abnormality in the power storage system 90 when starting or stopping the crane. The crane system is activated using the activation operation as a trigger. The starting operation may be configured by starting means such as a starting button or a starting key. The start-up operation can be performed by an operator in the operator's cab. In the case of remote control, the activation means may be provided in a control room (management room) that remotely controls the crane, or may be provided in a remote control means that can be used outside the operator's room. The crane may be terminated using a termination operation on the starting means as a trigger, or a dedicated button (termination means) may be provided separately.

The abnormality in the power storage system to be diagnosed is not particularly limited, but may be, for example, an abnormality in the power storage means (battery, capacitor, or combination thereof) (internal resistance abnormality, deterioration abnormality, temperature abnormality, voltage abnormality), It may also include abnormalities in means (switches) or resistors and capacitors. In the case of having a plurality of power storage means connected in series, the life span will be extended if the voltages of the power storage means are evenly balanced, so the voltage state may be detected at the time of startup or termination. Furthermore, by measuring the internal resistance and temperature of each power storage means at this time, it is possible to detect internal resistance abnormalities and temperature abnormalities prior to crane operation.

The crane system further includes an abnormality notification section 92. The abnormality notification unit 92 detects an abnormality and reports the existence of the abnormality at the time of startup, or detects the abnormality and reports the existence of the abnormality at the time of termination.

The abnormality notification unit 92 transmits information to a notification means provided in the remote control means in the case of remote operation, to a notification means provided in the administration building via the communication means in the case of automatic operation, and to a notification means provided in the administration building in the case of manual operation. An abnormality is notified to a notification means provided in the driver's cab.

The abnormality notification unit 92 can change the notification content depending on the type of abnormality or the degree of urgency. For example, if an abnormality occurs at a level that restricts work, a predetermined first level abnormality is notified and replacement or maintenance is recommended, but if an abnormality occurs at a level that does not restrict work, a predetermined first level abnormality is notified. A second level abnormality lower than the second level may be notified.

The crane may start work in a work mode that does not use the power storage system 90 by performing a predetermined mode change operation when it is determined that an abnormality has occurred and the abnormality is notified or work is restricted. . In a work mode that does not utilize this power storage system 90, at least one of the traveling speed and the operating speed of the hanging section may be limited.

The crane system of FIG. 8 and the power electronics device 300 of FIG. 3 can be associated as follows.
Figure 8 Figure 3
Controller 80 Controller 240, gate driver 232
Power storage device 67 DC power supply 202
Inrush current prevention circuit 76A Inrush current prevention circuit 210
Power conversion device 68 Converter device 230
Smoothing capacitor 72 DC link capacitor 220
Positive side bus bar 70P DC link 204

One of the abnormalities monitored by the controller 80 may be deterioration or failure of the relay or electromagnetic contactor of the inrush current prevention circuit 76A. In this case, the controller 80 may detect deterioration or failure of the relay or electromagnetic contactor by the method described with reference to FIGS. 3 and 4.

Although the present invention has been described using specific words and phrases based on the embodiments, the embodiments merely illustrate the principles and applications of the present invention, and the embodiments do not include the scope of the claims. Many modifications and changes in arrangement are possible without departing from the spirit of the present invention.

200 Power electronics equipment 202 DC power supply 204 DC link 210 Inrush current prevention circuit 220 DC link capacitor 230 Converter device 232 Gate driver 234 Current sensor 240 Controller 242 Converter controller 244 Judgment device MC1 First switch RY1 Second switch 300 Power electronics equipment 302 DC Power supply 304 DC link 306 Load 310 Inrush current prevention circuit 320 Smoothing capacitor 330 Load drive device 332 Load

INDUSTRIAL APPLICATION This invention can be utilized for an industrial machine.

Claims (6)

The main body and
A hanging work part,
a drive unit that drives the hanging work unit;
a power storage system that supplies power to the drive unit;
Equipped with
It has a function of diagnosing an abnormality in the electricity storage system at the time of startup or termination ,
further comprising an abnormality reporting unit that reports the existence of the abnormality,
The abnormality reporting unit is
A crane that starts a mode in which the power storage system is not used by a predetermined mode change operation in a state where it is determined that an abnormality has occurred and the abnormality is notified or work is restricted. The abnormality notification unit changes the notification content according to the type of abnormality,
In the case of an abnormality at a level that restricts work, a predetermined first level abnormality is notified,
The crane according to claim 1, wherein when an abnormality occurs at a level where replacement or maintenance is recommended but work is not restricted, a second level abnormality lower than the first level is notified. Further equipped with a running part,
The crane according to claim 1 or 2 , wherein in the mode in which the power storage system is not used, at least one of a traveling speed of the traveling section and an operating speed of the hanging section is limited. The crane according to claim 1 or 2 , wherein the abnormality notification section notifies a notification means provided in a remote control means of the abnormality in the case of remote control. The crane according to claim 1 or 2, wherein the abnormality notification unit notifies a notification means provided in an administration building of the abnormality via a communication means in the case of automatic operation. The crane according to claim 1 or 2 , wherein the abnormality notification unit notifies a notification means provided in an operator's cab of the abnormality in the case of manual operation.

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