WO2019123800A1

WO2019123800A1 - Crane and power electronics equipment

Info

Publication number: WO2019123800A1
Application number: PCT/JP2018/038446
Authority: WO
Inventors: 泰久田坂; 英昭湯浅
Original assignee: 住友重機械工業株式会社
Priority date: 2017-12-21
Filing date: 2018-10-16
Publication date: 2019-06-27
Also published as: TW201927677A; JP2023083270A; TWI772553B; JP7272961B2; JP7432033B2; JPWO2019123800A1

Abstract

Power electronics equipment 200 comprises a DC link capacitor 220 and an inrush current prevention circuit 210. A tester 244 gives a cut off instruction or a conduction instruction to a switch RY1, MC1 during testing and detects an abnormality in the switch RY1, MC1 on the basis of the voltage VDC of the DC link capacitor 220 or the current IIN flowing to the inrush current prevention circuit 210 at that time.

Description

Cranes and power electronics equipment

The present invention relates to a crane and power electronics equipment.

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

JP 2006-131311 A JP 2007-295699 A JP 2005-116485 A

1. Power electronics equipment is used for hybridizing cranes. The power electronics device mainly includes a capacitor and a converter, and is connected to the DC bus of the crane. The startup operation of the crane also starts up the power electronics equipment. When electrically connecting a DC bus and a capacitor, a power electronics device with high reliability in terms of safety is desirable.

2. FIG. 1 is a block diagram of a conventional power electronic device. The power electronics device 100R includes a motor 102 that is a load, a converter device 110, and a load driving device 120. Converter 110 generates a DC link voltage _{V DC} boosts the DC voltage _{V E} from the DC power source 104, such as a battery, supplies to a load driving device 120 via a DC link 130. The load drive device 120 is, for example, a motor drive device, and includes an inverter 122 that drives a motor 102 that 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 electronic device 100R starts up, the charges of 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. In order to prevent this, a charging resistor R _J , a relay RY1 and a magnetic contactor MC1 are provided. Introduction relay RY1 is turned on, DC link capacitor 132 is charged slowly via a charging resistor _{R J} and a diode D11. Also, the smoothing capacitor 124 is gently charged via the charging resistor R2.

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

Relays and electromagnetic contactors (hereinafter collectively referred to as switches) have mechanical contacts, and thus deteriorate with time due to oxidation and wear.

In the power electronic device 100R of FIG. 1, the deterioration with time of the relay RY1 and the magnetic contactor MC1 particularly becomes a problem. Therefore, in general, parts with an auxiliary contact are adopted as these switches, and failure detection (welding or open detection) using an answer back signal is widely performed.

FIG. 2 is a block diagram of a conventional power electronic device. The power electronic device 100S of FIG. 2 further includes a redundant switch RY2 on the negative electrode (N pole) side instead of using a switch having no auxiliary contact. Then, the switch RY1 (MC1) on the positive electrode side and the switch RY2 on the negative electrode side are sequentially conducted or disconnected, and when the voltage or current in each state deviates from the expected value in the normal state, it is determined as abnormal.

A switch with an auxiliary contact used in the power electronic device 100R of FIG. 1 is generally expensive, often large in size, and sometimes has difficulty in adoption.

Further, in the power electronic device 100S of FIG. 2, since it is necessary to add a redundant switch RY2, the size of the power electronic device 100S becomes large and the cost becomes high.

The present invention has been made in such a situation, and one of the exemplary objects of an embodiment thereof is a crane equipped with a power electronic device having higher safety at startup and a power electronic device mounted on the crane. It is to provide. In addition, one of the exemplary objects of the embodiment is to provide a power electronic device capable of detecting the deterioration of the switch.

One aspect of the present invention relates to a crane. The crane includes a drive unit that drives the main body unit, the suspension operation unit, the traveling unit, and the suspension operation unit, and a storage system that supplies power to the drive unit. The crane has a function of diagnosing an abnormality of the storage system at startup or termination.

2. One aspect of the present invention relates to power electronics devices. The power electronics device provides a capacitor, an inrush current prevention circuit including a switch provided between the DC power supply and the capacitor, and gives a switch command or conduction command to the switch in the determination period, and prevents the voltage or inrush current of the capacitor at that time. And a determinator for detecting a switch abnormality based on the current flowing through the circuit.

It is to be noted that any combination of the above-described constituent elements, or one in which the constituent elements and expressions of the present invention are mutually replaced among methods, apparatuses, systems, etc. is also effective as an aspect of the present invention.

According to an aspect of the present invention, it is possible to provide a crane equipped with a power electronic device with higher safety at startup and a power electronic device mounted on the crane. Further, according to an aspect of the present invention, deterioration of the switch can be detected.

It is a block diagram of the conventional power electronics device. It is a block diagram of the conventional power electronics device. It is a block diagram of the electronic device which concerns on embodiment. It is a figure explaining abnormality detection by a judgment device. It is a figure explaining abnormality detection by a judgment device. It is a block diagram showing the power electronics device concerning a modification. 7A and 7B are a schematic front view and a schematic side view, respectively, of a crane system according to the present embodiment. FIG. 8 is a power system diagram of the crane system.

(Overview of the embodiment)
One embodiment disclosed herein relates to a crane. The crane includes a drive unit that drives the main body unit, the suspension operation unit, the traveling unit, and the suspension operation unit, and a storage system that supplies power to the drive unit. The crane has a function of diagnosing an abnormality of the storage system at startup or termination.

The crane may include an abnormality notification unit that detects an abnormality at startup and reports the presence of the abnormality, or detects an abnormality at the end and reports the presence of the abnormality.

The abnormality notification unit is a notification unit provided in the remote control unit in the case of remote control, and in the case of automatic operation, is a notification unit provided in the management building via the communication unit, and in the case of manual operation, the operation You may alert | report abnormality to the alerting | reporting means provided indoors.

The abnormality notification unit may change the notification content according to the type of abnormality. In the case of an abnormality at a level where work is restricted, an alarm of a predetermined first level is reported, replacement or maintenance is recommended, but when an abnormality at a level where work is not restricted has occurred, from the first level The low level second level abnormality may be reported.

In a state where it is determined that an abnormality has occurred and notification of an abnormality or work restriction has been made, the work may be started in a work mode not using the power storage system by a predetermined mode change operation.

In the operation mode not using the storage system, at least one of the traveling speed and the operating speed of the suspension may be limited.

One embodiment disclosed herein relates to power electronics devices. The power electronics device provides a capacitor, an inrush current prevention circuit including a switch provided between the DC power supply and the capacitor, and gives a switch command or conduction command to the switch in the determination period, and prevents the voltage or inrush current of the capacitor at that time. And a determinator for detecting a switch abnormality based on the current flowing through the circuit. According to this embodiment, deterioration of the switch can be detected without using a switch with an auxiliary contact or a redundant switch. In addition, the cost of power electronics can be reduced.

The determiner temporarily gives a shutoff command to the switch during a charging period for giving a conduction command to the switch to charge the capacitor, and judges the presence or absence of an abnormality based on a change in current flowing in the inrush current prevention circuit at that time. You may If the switch is shut off normally while the switch is commanded to shut off, the current will be zero. On the contrary, when deterioration such as welding occurs in the switch, the current continues to flow. Therefore, the abnormality of the switch can be determined based on the current state of the switch (conduction / shutdown) and the change of the current.

The determiner may temporarily give a shutoff command to the switch during a charging period for giving a conduction command to the switch to charge the capacitor, and judge presence or absence of abnormality based on a change in voltage of the capacitor at that time. . If the switch is shut off normally while the shutoff command is given to the switch, the charge on the capacitor is stopped, and the voltage change is zero. On the contrary, when deterioration such as welding occurs in the switch, the charging current to the capacitor continues to flow, and the voltage of the capacitor continues to increase. Therefore, the abnormality of the switch can be determined based on the current state of the switch (conduction / shutdown) and the voltage change of the capacitor.

The power electronics device may further comprise a converter device provided between the inrush current protection circuit and the capacitor. The converter device may perform switching operation in a state where a shutoff command is given to the switch, and the presence or absence of abnormality may be determined based on the current flowing through the inrush current prevention circuit at that time.

If the switch is normally disconnected in the state where the switch command is given to the switch, the current flowing through the inrush current prevention circuit is zero even if the converter device is switched. On the other hand, when deterioration such as welding occurs in the switch, current flows through the inrush current prevention circuit. Therefore, the presence or absence of abnormality can be determined based on the current.

The power electronics device may further comprise a converter device provided between the inrush current protection circuit and the capacitor. The converter device may perform switching operation in a state where a shutoff command is given to the switch, and the presence or absence of abnormality may be determined based on the voltage of the capacitor at that time.

If the switch is normally shut off in the state where the switch is instructed to shut off, the current flowing through the inrush current prevention circuit is zero even if the converter device is switched, so the voltage of the capacitor does not rise. On the other hand, when deterioration such as welding occurs in the switch, the current flows through the inrush current prevention circuit, and the voltage of the capacitor rises. Therefore, the presence or absence of abnormality can be determined based on the voltage of the capacitor.

Embodiment
Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and duplicating descriptions will be omitted as appropriate. In addition, the embodiments do not limit the invention and are merely examples, and all the features and combinations thereof described in the embodiments are not necessarily essential to the invention.

In the present specification, “the state in which the member A is connected to the member B” means that the members A and B are electrically connected in addition to the case where the members A and B are physically and directly connected. It also includes the case of indirect connection via other members that do not substantially affect the connection state of the connection or do not impair the function or effect provided by the connection.

Similarly, "a state where the member C is provided between the member A and the member B" means that the member A and the member C, or the member B and the member C are directly connected, and It also includes the case of indirect connection via other members that do not substantially affect the connection state of the connection or do not impair the function or effect provided by the connection.

The vertical and horizontal axes of the waveform diagrams and time charts referred to in the present specification are scaled up and down appropriately to facilitate understanding, and each waveform shown is also simplified for ease of understanding. Or exaggerated or emphasized.

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

DC power supply 202 is a battery or a capacitor or an external converter, generates a DC voltage (also referred to as input voltage) V _E. 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 FIG. 1 or 2 is connected to the DC link 204. The type of load is not particularly limited.

Immediately after start-up of power electronic device 200, in a state where DC link capacitor 220 has a small amount of charge and DC link voltage V _DC is low, rush current when input voltage V _E is applied to DC link capacitor 220 via a low impedance path. Flows. In order 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 preventing circuit 210 includes a first switch MC1, the charging resistor _{R J} and the second switch RY1 is provided in series with the parallel paths to the first switch MC1. For example, the first switch MC1 is a magnetic 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. Converter device 230 in the operating state, boosts the input voltage _{V E,} to generate a high DC link voltage _{V DC} from the DC voltage _{V E} to the DC link 204 (a power running operation). The controller 240 includes a converter controller 242 that controls the converter device 230. Converter controller 242 generates control signal S _CTRL that defines the duty ratio of the gate signal of converter device 230.

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

The gate driver 232 drives the transistors M1 and M2 of the converter device 230 based on the duty ratio indicated by the control signal S _CTRL .

The current sensor 234 is, for example, current transformer, for detecting a current _{I L} flowing through the reactor L1. The controller 240 receives a digital value D _IL indicating the current I _L and a digital value D _VE indicating the input voltage V _E. The feedback control in the converter controller 242, and the input voltage _{V E,} may reflect the current _{I L} flowing through the reactor L1 of the converter device 230.

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

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

In the charging period immediately after the start of the power electronic device 200, the controller 240 stops the converter device 230 and turns on the second switch RY1. Thereby, the 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 possibility of inrush current to the DC link capacitor 220, the first switch MC1 is turned on. Thereafter, the controller 240 starts the operation of the converter device 230.

Abnormality detection of switches of the inrush current prevention circuit 210 will be described. The controller 240 includes a determiner 244. In the determination period, the determiner 244 gives the switch MC1 or RY1 a shutoff command or a conduction command, and the command (the use status of the switch) and the voltage V _DC of the DC link capacitor 220 or the rush current prevention circuit 210 at that time. An abnormality of the switches MC1 and RY1 is detected based on the combination of currents.

The current sensor 234 can be grasped as detecting the current (referred to as input current) I _IN flowing to 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 nothing but the charge current I _CHG during the charging period.

Hereinafter, abnormality detection by the determiner 244 will be described with reference to three embodiments.

(First embodiment)
FIG. 4 is a diagram for explaining abnormality detection by the determination unit 244. As shown in FIG.
At time _{t 0,} the controller 240 starts the charging of the DC link capacitor 220 provide a conduction command to the second switch RY1. The controller 240 inserts the determination period τ _DET1 into the charge period, and temporarily gives a cutoff command (t ₁ to t ₂ ) 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 of the input current I _IN flowing through the inrush current prevention circuit in the determination period τ _DET1 .

If the second switch RY1 is normally disconnected while the second switch RY1 is given a cutoff command, the input current I _IN becomes zero as shown by the solid line. On the other hand, when deterioration such as welding occurs in the second switch RY1, as shown by the alternate long and short dash line, the non-zero input current I _IN continues to flow. Therefore, the determiner 244 can determine the abnormality of the switch based on the input current I _IN in the determination period τ _DET1 . For example determiner 244, when the digital value DI _L in the determination period tau _DET1 is higher than a predetermined threshold abnormality may be determined to be normal when low.

The end time _{t 2} of the determination period tau _DET1, a second switch RY1 may be on again. The increased DC link voltage V _DC until the input voltage V _E is substantially equal to the voltage level at time t ₃ when there is no possibility of inrush current may provide a conduction command to the first switch MC1. Then, the converter device 230 at time _{t 4} is started operation.

Incidentally, the end time _{t 2} of the determination period tau _DET1, if DC link voltage _{V DC} is sufficiently high to the extent there is no risk of inrush current, and turned immediately first switch MC1 at time _{t 2,} the first switch The DC link capacitor 220 may be charged via the MC1.

Second Embodiment
Continuing to refer to FIG. In the second embodiment, the determiner 244 determines the presence or absence of an abnormality based on the change of the DC link voltage V _DC in the determination period τ _DET1 . If the second switch RY1 is normally disconnected while the second switch RY1 is given a cutoff command, the charging to the DC link capacitor 220 is stopped, so the rise of the DC link voltage V _DC is stopped as shown by the solid line. And its voltage change is zero. On the other hand, when deterioration such as welding occurs in the second switch RY1, the charging current I _CHG continues to flow in the DC link capacitor 220, so the DC link voltage V _DC continues to increase as shown by the one-dot chain line. Therefore, the determiner 244 can determine the abnormality of the second switch RY1 based on the DC link voltage V _DC in the determination period τ _DET1 . For example, the determiner 244 may determine normal when the amount of change of the digital value D _VDC in the determination period τ _DET1 is substantially zero and abnormal when the amount of change is not zero. More specifically, the digital value D _VDC is sampled at each of the start time t ₁ and the end time t ₂ of the determination period, and when the difference between them is larger than a predetermined threshold value, it is determined as abnormal. May be

Subsequently, the determination period τ _DET1 in the first embodiment or the second embodiment will be described. For example the determination period tau _DET1 is a after a predetermined delay time from the charging start time t _0, may be the start time t ₁ of the determination period tau.

Or to monitor the input voltage _{V E} immediately after startup, to determine the threshold K × _{V E} multiplied by the coefficient K (K <1) to an input voltage _{V E,} DC link voltage _{V DC} reaches the threshold time may be used as the start time t ₁ of the determination period τ a.

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

Third Embodiment
FIG. 5 is a diagram for explaining the abnormality detection by the determination unit 244. During the non-charging period after the end of the charging period, the determination period τ _DET2 is inserted. During the determination period τ _DET2 , the controller 240 is given a cutoff command to both the first switch MC1 and the second switch RY1. Then, converter device 230 is brought into an operating state.

For example the determination period tau _DET2 may be inserted in the vicinity of the time _{t 3} in FIG. 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 normally turned off when the converter device 230 performs switching operation, the DC link voltage V _DC does not increase as shown by the solid line, and the original voltage Maintain the level (here V _E ). If an abnormality occurs in any of the switches MC1 and RY1, as indicated by the one-dot and dash line, the DC link voltage V _DC rises as a result of the boosting operation of the converter device 230. Therefore, the determiner 244 can detect an abnormality of the switches MC1 and RY1 based on the voltage change amount in the determination period τ _DET2 .

For example, the determiner 244 may determine normal when the amount of change of the digital value D _VDC in the determination period τ _DET2 is substantially zero and abnormal when the amount of change is not zero. More specifically, the digital value D _VDC is sampled at each of the start time t ₁ and the end time t ₂ of the determination period, and when the difference between them is larger than a predetermined threshold value, it is determined as abnormal. May be

Fourth Embodiment
Continuing to refer to FIG. In the fourth embodiment, the determiner 244 determines the presence or absence of an abnormality based on the change of the input current I _IN in the determination period τ _DET2 . If both the first switch MC1 and the second switch RY1 are normally disconnected in the determination period τ _DET2 , the input current I _IN is zero as indicated by the solid line. On the contrary, when any one of the first switch MC1 and the second switch RY1 has an abnormality, the input current I _IN becomes non-zero as shown by the one-dot chain line. Therefore, the determiner 244 can determine the abnormality of the switch based on the input current I _IN in the determination period τ _DET2 . For example determiner 244, when the digital value DI _L in the determination period tau _DET2 is higher than a predetermined threshold abnormality may be determined to be normal when low.

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

(Modification)
In the embodiment, the abnormality detection of the switch of the inrush current prevention circuit 210 provided in the front stage of the converter device 230 has been described, but the application of the present invention is not limited thereto. As shown in FIG. 1 and FIG. 2, the inrush current prevention circuit including the resistor R2 and the switch MC2 is provided at the front stage of the load driving device 120, and the present invention can be applied to abnormality detection of the switch MC2. FIG. 6 is a block diagram showing a power electronic device 300 according to a modification. DC power supply 302 includes a converter that generates DC link voltage V _DC at 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. The load drive device 330 drives a load 306 such as a motor based on the DC voltage generated in the smoothing capacitor 320.

The controller 340 controls the switches MC2 and RY2 and the load driver 330 to detect an abnormality in the switches MC2 and RY2. As the detection method, the same method as the first to fourth embodiments described above can be adopted.

First, if employing the second embodiment, the _{V E} of the above description and FIG. 4 read as _{V _DC,} may be read as a _{V DC} and _{V IN.} When the third and fourth embodiments are employed, a switch off command is given to the switches MC2 and RY2 during the determination period τ _DET2 to operate the load driving device 330, and the change in the voltage V _IN or the current I ₁ at that time is performed. It is sufficient to detect the change.

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

Although the present invention can be applied to a power electronic device having a switch with an auxiliary contact and a redundant switch RY2 from the viewpoint of double protection, a switch with an auxiliary contact and a redundant switch RY2 are applicable. It is understood that the effects of simple configuration, size reduction, cost reduction and the like become even more remarkable if there are no power electronic devices.

In power electronics equipment, when something called abnormality is detected, it notifies a higher controller installed in the industrial machine etc., displays abnormality on the display part etc. provided in the industrial machine etc., or the industrial machine Stopping the system will contribute to the improvement of safety. The notification may be made in a preliminary or forecast manner, and in this case, it is excellent from the viewpoint of failure prediction that does not stop the industrial machine or the like.

Although the application of the power electronic device is not particularly limited, for example, industrial machines such as injection molding machines and presses, construction machines such as shovels and cranes, and transport vehicles such as forklifts and unmanned transport vehicles It is applicable to a machine etc.).

7A and 7B are a schematic front view and a schematic side view, respectively, of a crane system according to the present embodiment. A plurality of columns 40 support the girder 41. The pillar 40 and the girder 41 constitute a portal frame. A wheel 42 is attached to the lower end of the pillar 40, and a portal frame travels along the rail 43. The direction perpendicular to the paper surface of FIG. 4A and the left and right direction of FIG. 4B correspond to the traveling direction. A trolley 45 is mounted on the girder 41. A hoisting machine 46 is mounted on the trolley 45. A portal-type frame and a wheel 42 constitute a main body, and a trolley 45, a hoist 46 and a suspension work part (a hanger 47 and a wire) constitute a work part.

A plurality of electric actuators drive the respective operating units. For example, the traveling motor 51 mounted on the portal frame drives the wheels 42. A traverse motor 52 mounted on the trolley 45 moves the trolley 45 in the transverse direction. The horizontal direction of FIG. 4A and the direction perpendicular to the paper surface of FIG. 4B correspond to the transverse direction. The hoisting machine 46 includes a hoisting motor 53, and winds up and unwinds a wire to which a hanging tool 47 such as a hook is attached at its tip. Thus, the electric actuators such as the hoisting motor 53, the traversing motor 52, and the traveling motor 51 operate the hanger 47, the trolley 45, and the wheel 42, respectively.

An AC power supply 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 portal frame. AC power supply 60 includes an engine 61 and a generator 62. The AC power supply 60 supplies driving power to the winding motor 53, the traverse motor 52, and the traveling motor 51. Further, power storage device 67 is charged by the power supplied from AC power supply 60.

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

FIG. 8 is a power system diagram of the crane system. An AC power supply 60 is connected to the DC bus 70 via a rectifier 63 and a power converter 65. The power converter 65 converts the DC power output from the AC power source 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 bus 70P and the negative bus 70N of the DC bus 70.

Power storage device 67 is connected to DC bus 70 via power conversion device 68. Power converter 68 controls charge and discharge of power storage device 67. When discharging power storage device 67, 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 power bus 70 to power storage device 67.

A traveling motor 51 is connected to the DC bus 70 via an inverter 54 and a power converter (DC-DC converter) 57. A transverse motor 52 is connected to the DC bus 70 via an inverter 55 and a power converter (DC-DC converter) 58. A hoisting motor 53 is connected to the DC bus 70 via an inverter 56 and a power converter (DC-DC converter) 59.

Power converters

57, 58, 59 respectively boost the voltage of DC bus 70, and supply the boosted power to

inverters

54, 55, 56.

The controller 80 controls the

power conversion devices

57, 58, 59, 65, 68, and the

inverters

54, 55, 56 so that power is supplied from the DC bus 70 to the traveling motor 51, the traverse motor 52, and the winding motor 53. Supply. The controller 80 controls the

power conversion devices

57, 58, 59, 65 and 68 to maintain the voltage of the DC bus 70 at a preset target value. When the hoisting motor 53 performs the lowering operation, the controller 80 controls the inverter 56 and the power conversion device 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 by this regenerative power.

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

The controller 80 has a function of diagnosing an abnormality of the storage system 90 at the start or end of the crane. The crane system is triggered by a trigger operation. The activation operation may be configured by activation means such as an activation button or activation key. The start operation can be performed by the operator in the cab. In the case of remote control, the activation means may be provided in a control room (administration room) that remotely controls the crane, or may be provided in a remote control means available outside the driver's cab. The crane may be terminated using a termination operation to the starting means as a trigger, or may be provided with a dedicated button (termination means) separately.

The abnormality of the storage system to be diagnosed is not particularly limited, but may be, for example, an abnormality (internal resistance abnormality, deterioration abnormality, temperature abnormality, voltage abnormality) of the storage means (battery or capacitor, or a combination thereof) It may include means (switches) or resistance or capacitor abnormalities. In the case of having a plurality of storage means connected in series, if the voltage is equally balanced in each storage means, the life is extended, so the voltage state may be detected at the time of start or end. At this time, by measuring the internal resistance and temperature of each storage means, internal resistance abnormality and temperature abnormality can be detected prior to the operation of the crane.

The crane system further includes an abnormality notification unit 92. The abnormality notification unit 92 detects an abnormality at startup and notifies the presence of an abnormality, or detects an abnormality at end and notifies an existence of an abnormality.

The abnormality notification unit 92 is a notification unit provided to the remote control unit in the case of remote control, and is a notification unit provided in the management building via the communication unit in the case of automatic operation, in the case of a manual operation. An alarm is provided in the driver's cabin to notify of an abnormality.

The abnormality notification unit 92 can change the notification content according to the type of abnormality or the degree of urgency. For example, in the case of an abnormality at a level at which work is restricted, a predetermined first level abnormality is notified, and replacement or maintenance is recommended, but at a level at which an operation is not restricted, a first abnormality is generated. The second level abnormality lower than the level may be notified.

The crane may start the operation in the operation mode not using the storage system 90 by a predetermined mode change operation in a state where it is determined that an abnormality has occurred and notification of an abnormality or operation restriction has been made. . In the operation mode in which the storage system 90 is not used, at least one of the traveling speed and the operating speed of the hanging portion may be limited.

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

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

While the present invention has been described using specific terms based on the embodiments, the embodiments merely show the principles and applications of the present invention, and the embodiments are defined in the claims. Many variations and modifications of the arrangement can be made without departing from the concept 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 Determination Unit MC1 1st Switch RY 1 2nd Switch 300 Power Electronics Equipment 302 DC Power supply 304 DC link 306 Load 310 Inrush current protection circuit 320 Smoothing capacitor 330 Load driver 332 Load

The present invention is applicable to industrial machines.

Claims

Body part,
A hanging work unit,
A driving unit for driving the traveling unit and the hanging operation unit;
A storage system for supplying power to the drive unit;
Equipped with
The crane which has a function which diagnoses the abnormalities of the electricity storage system at the time of starting or completion.
The crane according to claim 1, further comprising: an abnormality notification unit that detects an abnormality at startup and reports an existence of the abnormality, or detects an abnormality at an end and reports an existence of the abnormality.
The abnormality notification unit
In the case of remote control, informing means provided in the remote control means,
In the case of automatic operation, the notification means provided to the management building through the communication means,
In the case of manual operation, the notification means provided in the driver's cab
The crane according to claim 2, which reports an abnormality.
The abnormality notification unit changes the notification content according to the type of abnormality,
In the case of an abnormality at a level at which work is limited, an alarm of a predetermined first level is notified,
The crane according to claim 2, wherein if the level of abnormality that replacement or maintenance is recommended but the operation is not limited occurs, the second level of abnormality lower than the first level is notified.
The operation is started in a work mode not using the power storage system by a predetermined mode change operation in a state where it is determined that an abnormality has occurred and notification of an abnormality or work restriction has been made. Crane.
The crane according to claim 5, wherein at least one of a traveling speed and an operating speed of the suspension portion is limited in the operation mode not using the storage system.
A capacitor,
An inrush current prevention circuit including a switch provided between a DC power supply and the capacitor;
A determinator for giving a shutoff command or a conduction command to the switch in a judgment period, and detecting an abnormality of the switch based on a voltage of the capacitor at that time or a current flowing in the inrush current prevention circuit;
Power electronics equipment characterized by comprising.
The determination unit temporarily gives a shutoff command to the switch during a charging period for giving a conduction command to the switch to charge the capacitor, and based on a change in current flowing in the inrush current prevention circuit at that time. The power electronics device according to claim 7, wherein the presence or absence of the abnormality is determined.
The determinator gives a conduction command to the switch to temporarily give a shutoff command to the switch during a charging period for charging the capacitor, and the presence or absence of the abnormality based on a change in voltage of the capacitor at that time. The power electronics device according to claim 8, characterized in that:
A converter device provided between the inrush current prevention circuit and the capacitor;
8. The converter device is subjected to switching operation in a state where a shutoff command is given to the switch, and the presence or absence of the abnormality is determined based on the current flowing through the inrush current prevention circuit at that time. Power electronics equipment.
A converter device provided between the inrush current prevention circuit and the capacitor;
8. The power electronic device according to claim 7, wherein the converter device is subjected to switching operation in a state where a shutoff command is given to the switch, and the presence or absence of the abnormality is determined based on the voltage of the capacitor at that time. .
Further comprising a load driver connected to the capacitor;
The load driving device is operated in a state where a shutoff command is given to the switch, and the presence or absence of the abnormality is determined based on the current flowing through the inrush current prevention circuit at that time. Power electronics equipment.
Further comprising a load driver connected to the capacitor;
8. The power electronic device according to claim 7, wherein the load driving device is operated in a state in which a shutoff command is given to the switch, and the presence or absence of the abnormality is determined based on the voltage of the capacitor at that time. .