JP7568667B2 - Drive device centralized management device - Google Patents

Description

An embodiment of the present invention relates to a drive device centralized management device that performs preventive maintenance of drive devices based on the operating status of the drive devices.

In a factory, when a drive device for driving a motor has broken down, the parts or supplies that make up the drive device are identified as causing the breakdown, and these are then replaced or repaired to return the drive device to an operational state. After identifying the parts or supplies that caused the breakdown, their model names, etc. are investigated, and if the parts or supplies with the investigated model names are no longer in production, etc., it is necessary to investigate alternatives. The investigated parts and supplies are ordered and arranged, and once they are obtained, the broken drive device can be repaired.

If, after a drive device breaks down, the cause of the failure is investigated and the parts and supplies that caused the failure are investigated and arranged for, the time required to actually obtain the necessary replacement parts and supplies and to repair the failure will be longer, resulting in longer downtime for the broken drive device. Since longer downtime directly leads to lower productivity in factories, it is desirable to reduce device downtime. While it would be possible to shorten downtime by providing spare drive devices, providing a large number of spare drive devices to avoid downtime due to the failure of some parts would increase costs and create problems such as the need to secure storage space.

There is a known preventive maintenance technology that calculates the replacement timing of parts and supplies that may break down in advance based on the lifespan of the parts and supplies (see, for example, Patent Documents 1 and 2). In Patent Document 1, a certain learning period is set for monitored data that is effective for preventive maintenance to identify a predictive calculation model, and trend monitoring and preventive maintenance are performed using the predictive calculation data and actual measurement data. In Patent Document 2, a high-speed network is used to collect temperature information and internal pressure information of the capacitor, and the state of the capacitor installed in the drive device during operation is monitored in a timely manner. If the temperature characteristics and internal pressure measurements of the capacitor exceed certain threshold values, it is determined to be a minor failure and an alarm is output, thereby performing preventive maintenance.

JP 2017-153208 A JP 2019-129593 A

The preventive maintenance device disclosed in Patent Document 1 performs preventive maintenance by performing identification using a predictive calculation model based on monitored data for the electric motor and drive unit, and then performing trend monitoring and anomaly detection using the predictive calculation data and actual measurement data. With this method, it is necessary to actually measure different parameters such as temperature and current for each part or item, and a separate measuring device for the actual measurements may be required.

In addition, to determine anomalies, it is necessary to collect characteristic parameters for each device. For devices where temperature changes, current values, etc. remain stable over a relatively long period of time, it is difficult to measure singular values, and for such devices, preventive maintenance may be difficult to implement.

The drive preventive maintenance system disclosed in Patent Document 2 can be applied when the temperature and pressure characteristics of the capacitor installed in the drive device are known in advance, but it cannot be applied to general drive devices for which such characteristics are not known, and it is also difficult to apply it to parts with limited life spans other than capacitors.

The present invention is directed to solving the above problems, and aims to provide a drive device centralized management device that can easily perform preventive maintenance on a larger number of motor-driven drive devices.

An embodiment of the present invention includes a calculation device configured to acquire data representing the operating time of the drive device from time series data of one or more control signals linked to identification data of the drive device, calculate a total operating time which is the sum of the operating times of the drive device to date, compare the total operating time with recommended replacement times preset for each part and item constituting the drive device, and, when the total operating time is equal to or greater than the recommended replacement time, output information identifying the part and item to be replaced together with the recommended replacement time from a replacement candidate database having information identifying the parts and items , wherein the calculation device has a life curve with the recommended replacement time as a threshold value, and when the drive device is operated in an overcurrent state, updates the life curve so as to advance the recommended replacement time depending on the period of operation in the overcurrent state .

According to the embodiment, a drive device centralized management device is realized that can easily perform preventive maintenance on a larger number of motor-driving drive devices.

1 is a schematic block diagram illustrating a drive device collective management system having a drive device collective management device according to an embodiment; 3 is a schematic table diagram illustrating a database included in the data storage and collection device. FIG. 4 is a schematic table diagram illustrating a database included in the drive device central management device. FIG. 11 is a schematic example of a life characteristic diagram of parts included in the drive device centralized management device;

Each embodiment will be described below with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing.
In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals and detailed descriptions thereof will be omitted as appropriate.

FIG. 1 is a schematic block diagram illustrating a drive device integrated management system according to an embodiment.
As shown in FIG. 1, the drive device centralized management system 100 includes a drive device centralized management device 10, a data storage and collection device 20, a display device 30, drive devices 40, 52, 54, 56, and a control network 102. The drive device centralized management device 10, the data storage and collection device 20, the display device 30, and the drive devices 40, 52, 54, 56 are communicatively connected to each other via the control network 102. In this example, four drive devices 40, 52, 54, 56 are provided, but one or more drive devices may be connected to the control network. The control network 102 is an industrial communication network or the like, and can perform reliable communication between connected devices at a fixed cycle and at high speed, for example. The control network 102 may be compatible with wired communication, wireless communication, or a combination of these.

The drive device centralized management device 10 is connected to the data storage and collection device 20 via a control network 102. The drive device centralized management device 10 acquires data on the operating time of each of the drive devices 40, 52, 54, and 56 from the data storage and collection device 20. The drive device centralized management device 10 calculates the total operating time, which is the sum of the operating times of each of the drive devices 40, 52, 54, and 56, and outputs the time to replace the parts and supplies (hereinafter referred to as parts, etc.) that make up the drive devices 40, 52, 54, and 56, based on the life characteristics of those parts and supplies. When outputting the replacement time of the parts, etc. to be replaced, the drive device centralized management device 10 also outputs information for identifying the parts, etc. to be replaced. The information for identifying the parts, etc. to be replaced is, for example, the name on the circuit diagram of the parts, etc. and the model name, etc. In addition, information on the manufacturer, etc. that supplies the parts, etc. with that model name may also be output.

The data storage and collection device 20 is connected to the drive devices 40, 52, 54, and 56 via the control network 102. The data storage and collection device 20 collects control signals related to the operation of each of the drive devices 40, 52, 54, and 56 as time-series data from the drive devices 40, 52, 54, and 56. The time-series data collected by the data storage and collection device 20 is stored, for example, as a database for each of the drive devices 40, 52, 54, and 56. These data may be stored in a storage device that the data storage and collection device 20 itself has, or may be stored in a storage device such as a data server connected via the control network.

In addition to the drive device, the data storage and collection device 20 can also collect time-series data of control signals from various devices, such as devices and sensors, connected to the control network 102. For example, the data storage and collection device 20 collects these control signals as time-series data via a control computer, such as a programmable logic controller (PLC), connected to the control network 102.

The display device 30 outputs the information on the replacement time output by the drive device centralized management device 10 and information for identifying parts that need to be replaced. In this example, an HMI terminal (represented as HMI in FIG. 1) is used as the display device, but it is of course possible to use another display device.

The drive devices 40, 52, 54, and 56 drive the motors connected to them. The drive devices 40, 52, 54, and 56 drive the motors connected to them at the desired rotation speed and drive torque according to commands generated by a PLC or the like connected to the control network 102. When a drive device detects an abnormal state such as an overcurrent or overvoltage in itself, the drive device may be able to store the timing and duration of the detection. Depending on the content and duration of such an abnormal state, the drive device may affect the lifespan of the components that make up the drive device. The data storage and collection device 20 can collect control signals related to such abnormal states generated by the drive device itself.

The drive devices 40, 52, 54, and 56 each have their own identification data so that the drive device centralized management device 10 can identify them. In this example, the drive device 40 has identification data ID1. The drive device 52 has identification data ID2, the drive device 54 has identification data ID4, and the drive device 56 has identification data ID6. Identification data is also assigned to the other devices and equipment connected to the control network 102. The time-series data collected by the data storage and collection device 20 is linked to the identification data, and the drive device centralized management device 10 can identify which drive device the control signal belongs to by specifying the identification data.

In this example, the drive device 40 is installed independently and drives one or more motors. The drive devices 52, 54, and 56 are installed in a stack of three in multiple tiers, and each drive device 52, 54, and 56 drives one or more motors in conjunction with each other. In this way, the drive devices can be in any form as long as they are connected to the data storage and collection device 20 via the control network 102.

The drive device centralized management device 10 is, for example, a computer device equipped with an arithmetic unit and a storage device. The drive device centralized management device 10 reads a program stored in the storage device and executes each step of the read program sequentially in the arithmetic unit. The operations and functions of the drive device centralized management device 10 described above and below are realized by one or more steps of the program executed in the arithmetic unit.

The operation of the drive device centralized management device 10 of the embodiment will be described.
FIG. 2 is a schematic table diagram illustrating a database included in the data archiving and collection device.
FIG. 2 shows a table diagram that shows the time series data of the control signals collected by the data storage and collection device 20 in relation to the drive device 40 having the identification data ID1. The database 12a is stored in, for example, a storage device of the data storage and collection device 20. In the example of FIG. 2, the time series data of the control signals for each identification data is shown for the drive device 40, but the data of the other drive devices 52, 54, and 56 are also stored in the database 12a in a similar format. Of course, the database 12a may also include time series data of the control signals of devices and equipment other than the drive devices. The control signals collected and stored by the data storage and collection device 20 are set in advance. In this embodiment, the selected control signals of all the drive devices 40, 52, 54, and 56 connected to the control network 102 are stored in the database 12a, but of course, the data of any selected drive device may be stored in the database 12a.

Database 12a stores time series data of multiple control signals for drive device 40 having identification data ID1. In this example, the control signals are represented by time series data regarding operation commands and overcurrent detection. The time series data of operation commands and overcurrent detection are linked to time data. The time data can include information on the date when the control data was acquired, making it possible to identify control data spanning a long period of time.

In this example, the operation command and overcurrent detection are shown as 1-bit binary signals of "1" or "0". When the operation command is "1", it indicates that the operation command is active, and when the operation command is "0", it indicates that the operation command is inactive. It goes without saying that the control signal is not limited to 1-bit data.

As shown in FIG. 2, the operation command is inactive at times t1 and t2. In other words, the drive device 40 is stopped. After that, at time ti, the operation command is made active and remains active until time tn. After that, at time tn+1, the operation command is made inactive. In other words, in this example, the drive device 40 starts operation at time ti and ends operation at time tn.

At time ti when the drive device 40 starts operation, the overcurrent detection is inactive and no overcurrent is detected. After that, for the period from time tn-1 to time tn, the overcurrent detection is active, and it is shown that an overcurrent is detected during this period. Note that in this example, i is an integer greater than 2, and n-2 is an integer greater than i+1.

The drive device centralized management device 10 monitors the operation commands of each drive device 40, 52, 54, 56, and stores the period during which the operation command was active for each drive device 40, 52, 54, 56. In this example, the drive device centralized management device 10 calculates the difference between time tn and time ti, and stores the calculated difference as the operating time of the drive device 40. After that, it calculates the difference between the time when the operation command was made active again and the time until it was made inactive, and adds the calculated difference to the stored operating time. In this way, the drive device centralized management device 10 calculates the total operating time for each drive device 40, 52, 54, 56, and stores the calculation results.

The drive device centralized management device 10 has data on the recommended replacement time for each part that has a lifespan. The data on the recommended replacement time is set in advance. Parts that have a lifespan include, for example, capacitors and their composite parts, capacitor modules, power modules that are switching elements made of power semiconductors, and insulating parts that use optical semiconductor elements. Specific examples of data on the recommended replacement time will be described later.

FIG. 3 is a schematic table diagram illustrating a database included in the drive device central management device.
3 shows a schematic example of the database 12b. The database 12b stores data identifying parts and the like that make up the drive device 40 having the identification data ID1. Needless to say, the database 12b also stores data identifying parts and the like that make up the other drive devices 52, 54, 56.
As shown in Fig. 3, the identification data ID1 of the database 12b stores the circuit diagram symbols of the components, the component names, and the names of multiple replacement candidates (represented as replacement candidates in Fig. 3). The circuit diagram symbols are, for example, circuit diagram symbols displayed on the display device 30. In this example, two types of replacement candidates are displayed, but three or more types may of course be displayed. Depending on the component, multiple replacement candidates may not be prepared, in which case information on one type of replacement candidate is stored. The replacement candidate column may be linked to information such as specifications or catalogs for the component, so that the information can be output together with the links.

The drive device centralized management device 10 monitors whether the recommended replacement time has been reached for each part, etc., that constitutes the drive device 40 having ID1. When the drive device centralized management device 10 detects a part, etc. that has reached the recommended replacement time, it outputs information about candidates for replaceable parts, etc., to the display device 30. The information output to the display device 30 includes information that identifies the drive device 40 as well as information that identifies the parts, etc., that should be replaced. Information that identifies the drive device 40 is obtained, for example, by highlighting the drive device 40 in a system configuration diagram that includes the drive devices 40, 52, 54, and 56 displayed on the display device 30, which is an HMI terminal. The information that outputs the parts, etc., that should be replaced are the symbols and names on the circuit diagram listed from the database 12b, and the model names of all candidates for parts, etc., that should be replaced. The information to be output is not limited to this, and for example, the operator of the drive device centralized management device 10 may be able to arbitrarily set the output information. Note that, when there is only one drive device for which the total operating time is calculated, the information output to the display device 30 does not need to include information that identifies the drive device.

FIG. 4 is a schematic diagram showing an example of life characteristics of parts included in the drive device centralized management device.
4, the drive device centralized management device 10 has data on the recommended replacement timing of parts and the like having a life span for each of the drive devices 40, 52, 54, and 56. Preferably, the drive device centralized management device 10 has data on the recommended replacement timing of all parts and the like having a life span.

The data on the recommended replacement timing of a part or parts with a life span is a life span curve 14 set based on, for example, an Arrhenius plot. Preferably, the life span curve 14 includes multiple life span curves 14a, 14b, and 14c. First, the life span curve 14a will be described.

Since a constant environmental temperature is maintained within a factory, the temperature inside the drive device 40 during operation is set, and the life curve 14a is determined and set in advance based on that temperature. In FIG. 4, the horizontal axis is the total operating time of the drive device 40. In FIG. 4, the vertical axis is the deterioration index. The deterioration index is set based on the number of defects found in the test quantity in which accelerated tests are performed on each part, etc., for example. In other words, the life curve 14a indicates that the longer the total operating time of the drive device 40, the greater the degree of deterioration of the parts, etc. The recommended replacement time is determined by setting any appropriate deterioration index before the part, etc. becomes defective.

Life curves 14b and 14c show the curves when the drive device 40 is temporarily operated in an overcurrent state. In this example, life curve 14 is set mainly due to deterioration of the chemicals that make up the parts, etc., caused by heat. When the drive device 40 is placed in an abnormal state such as an overcurrent or overvoltage, the thermal stress applied to the parts that make up the drive device 40 becomes large.

In this example, at total operating time (2), the data of life curve 14b is shifted vertically from that of life curve 14a. In other words, it shows that an overcurrent is detected at operating time (2), and the deterioration index of the part increases according to the period during which the drive device 40 is operated in an overcurrent state. In the case of life curve 14c, the overcurrent state continues for a longer period than in the case of life curve 14b. Therefore, the shift amount of the vertical axis of life curve 14a is larger. Note that the temperature rise of the target parts in an overcurrent state is calculated in advance by measurement, simulation, etc. Similarly, in the case of an overvoltage state, the temperature rise is calculated by measurement, simulation, etc. The same applies to other abnormal states.

The drive device centralized management device 10 uses a preset life curve 14a to determine the recommended replacement time. When an abnormal condition occurs in the operating status of the drive device 40, the life curve 14a is updated to life curves 14b and 14c according to the duration of the abnormal condition. The drive device centralized management device 10 determines the recommended replacement time for the part, etc. based on the updated life curves 14b and 14c.

In the case of FIG. 2, an overcurrent state is detected in the period from time tn-1 to time tn, and the drive device centralized management device 10 updates the life curve assuming that a temperature rise corresponding to the overcurrent state occurs in the period from time tn-1 to time tn.

In the above description, the deterioration index increases due to a rise in temperature of parts etc. when the drive device is in an abnormal state, but this is not limited to the above. For example, the life characteristics of each part etc. may be measured in advance based on the results of accelerated testing using voltage values and other parameters, and the results may be reflected in the life curve. In addition, the recommended replacement time is not limited to one stage, and may be a multiple-stage threshold value of two or more stages.

The effects of the drive device centralized management device 10 according to the embodiment will be described.
The drive device centralized management device 10 according to the embodiment can calculate the total operating time of the drive device having the identification data in real time based on the control signal for each identification data collected and stored by the data storage and collection device 20. The drive device centralized management device 10 has data on the recommended replacement time of the parts with a limited life that constitute the drive device for each drive device. Therefore, the drive device centralized management device 10 can determine whether the recommended replacement time has been reached for each part that constitutes the drive device. The recommended replacement time can be set with a margin for the life of the part, so that the operator of the drive device centralized management device 10 can know the time to replace the part before the drive device breaks down.

The drive device centralized management device 10 has a database 12b that stores information identifying parts that need to be replaced. Therefore, when the part that needs to be replaced reaches the recommended replacement time, the time is output, and the part that needs to be replaced can be identified and the information output. Information on the part that needs to be replaced can include information such as the model name and manufacturer of the part, so the operator of the drive device centralized management device 10 can easily arrange for the part to be replaced. As multiple candidates for information on the part that needs to be replaced can be stored in the database 12b, even if production of the part is discontinued, there is no need to investigate the target part again, making it easier to arrange for the part.

Some factories have introduced order management systems that handle ordering of parts and managing delivery dates. By linking the output information on parts to be replaced to such an order management system, it becomes possible to automate the ordering and arrangement of parts, etc., and achieve labor-saving in factory management.

The drive device centralized management device 10 according to the embodiment can use a life curve created based on the deterioration index of drive device parts and the like due to heat generation within the device or near the device to determine the recommended replacement time. There are established calculation methods for temperature-based life curves using Arrhenius plots and the like, and manufacturers of parts and the like have sufficient data. Therefore, it is possible to prepare life curves for more parts and the like, and it becomes possible to perform preventive maintenance on more drive devices connected to the control network 102, thereby shortening the line-down period and improving factory productivity.

The life curve of the drive device centralized management device 10 is updated according to the duration of an event that occurs when an abnormal condition such as overcurrent or overvoltage in the drive device causes greater heat generation. In the updated life curve, the deterioration index can rise in a shorter period of time, making it possible to predict the life of parts, etc. with high accuracy and perform preventive maintenance of the drive device.

In this way, it is possible to realize a centralized drive device management device that can perform comprehensive preventive maintenance of motor-driving drive devices.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

10 Drive device centralized management device, 12a, 12b Database, 14, 14a, 14b, 14c Life curve, 20 Data storage and collection device, 30 Display device, 40, 52, 54, 56 Drive device, 100 Drive device centralized management system

Claims (3)

acquiring data representing an operating time of the drive device from time series data of one or more control signals linked to identification data of the drive device;
Calculating a total operating time of the drive device, which is a sum of the operating times up to the present;
comparing the total operating time with recommended replacement times preset for parts and supplies constituting the drive device;
a calculation device configured to output, when the total operating time is equal to or greater than the recommended replacement time, information identifying the part and item to be replaced from a replacement candidate database having information identifying the part and item, together with the recommended replacement time ;
The computing device includes:
A life curve having the recommended replacement time as a threshold value,
a drive device central management device that updates the life curve so as to bring forward the recommended replacement time when the drive device is operated in an overcurrent state, depending on the period of operation in the overcurrent state . The drive device centralized management device according to claim 1, wherein the information identifying the parts and supplies to be replaced includes information corresponding to a plurality of candidates. the arithmetic unit acquires operation command data as data representing an operation time of the drive device, calculates the total operation time based on time series data of the operation command, acquires overcurrent detection data representing detection of an overcurrent of the drive device, and calculates an operation period in the overcurrent state based on the time series data of the overcurrent detection,
3. The drive device centralized management device according to claim 1 , wherein the operation command data and the overcurrent detection data are 1-bit binary signals .

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