Power conversion device, control device, data accumulation device, and data accumulation method

Abstract

The power conversion device (1) includes: a power conversion circuit (10) that performs power conversion between primary-side power and secondary-side power; a buffer data accumulation section (114) that repeatedly acquires a data set related to a state of the power conversion circuit (10) and stores the data set in a ring buffer (112) at a prescribed buffer period; a state monitoring section (121) that generates a trigger signal when a prescribed condition is satisfied with respect to a prescribed monitoring target state; and a data duplication section (115) that stores a plurality of data sets accumulated in the ring buffer (112) during a preservation target period up to a time point at which the trigger signal is generated in the data storage section (113) when the trigger signal is generated.

Description

Technical Field

[0001] This disclosure relates to power conversion devices, control devices, data storage devices, and data storage methods. Background Technology

[0002] Patent Document 1 discloses a machine tool information acquisition device, which is a device for acquiring machine tool information. It is characterized by comprising: a timing information recording unit for acquiring machine tool information sequentially at predetermined time intervals; an event information recording unit for recording at least one of the following: process information of the machining operation, tool information, operation panel information of the machine tool's control panel, workpiece information, and operator information; the change content and time when any of these changes, as well as the instruction and time when a machine tool control execution start or end instruction is given; and an output unit for outputting the timing data of the machine tool information recorded in the timing information recording unit and the event data recorded in the event information recording unit together.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-033346 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] This disclosure provides a power conversion device, a control device, a data storage device, and a data storage method, which are effective in balancing resource conservation in data storage with detailed data analysis.

[0008] Technical solution

[0009] One aspect of the power conversion apparatus disclosed herein includes: a power conversion circuit for performing power conversion between primary-side power and secondary-side power; a buffer data accumulation unit for repeatedly acquiring and storing data sets related to the state of the power conversion circuit in a ring buffer at a predetermined buffer period; a state monitoring unit for generating a trigger signal when the state of a predetermined monitored object meets predetermined conditions; and a data copying unit for storing multiple data sets accumulated in the ring buffer in a data storage unit during the storage period, including the time before the generation time of the trigger signal, when the trigger signal is generated.

[0010] Another aspect of the control device disclosed herein includes: a control unit for controlling a controlled object; a buffer data accumulation unit for repeatedly acquiring and storing data sets related to the state of the controlled object in a ring buffer at a predetermined buffer period; a state monitoring unit for generating a trigger signal when the state of the monitored object meets predetermined conditions; and a data copying unit for storing multiple data sets accumulated in the ring buffer in a data storage unit during the object storage period, including the time before the generation of the trigger signal, when the trigger signal is generated.

[0011] Another aspect of this disclosure provides a data storage device comprising: a buffer data storage unit that repeatedly acquires and stores data sets related to the state of a power conversion circuit that performs power conversion between primary and secondary power at a predetermined buffer period; a state monitoring unit that generates a trigger signal when the state of a predetermined monitored object meets predetermined conditions; and a data copying unit that, upon the generation of the trigger signal, stores multiple data sets accumulated in the ring buffer during the storage period, including the time prior to the generation of the trigger signal, in a data storage unit.

[0012] Another aspect of the data accumulation method disclosed herein includes: repeatedly acquiring and storing data sets related to the state of a power conversion circuit that performs power conversion between primary and secondary power at a predetermined buffer period; generating a trigger signal when the state of a predetermined monitored object meets predetermined conditions; and storing multiple data sets accumulated in the ring buffer during the period of the object being monitored, including the time before the generation time of the trigger signal, in a data storage unit when the trigger signal is generated.

[0013] Invention Effects

[0014] According to this disclosure, a power conversion device, a data storage device, and a data storage method can be provided, which are effective in balancing resource conservation in data storage and detailed data analysis. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the configuration of a power conversion device.

[0016] Figure 2 This is a timing diagram illustrating the relationship between the storage time of a long-period dataset, the start time of the object storage period, the trigger generation time, and the offset value.

[0017] Figure 3 This is a block diagram illustrating the hardware configuration of a control circuit.

[0018] Figure 4 This is a flowchart illustrating the power conversion control process.

[0019] Figure 5 This is a flowchart illustrating the process of buffering data accumulation.

[0020] Figure 6 This is a flowchart illustrating the process of accumulating log data.

[0021] Figure 7 This is a flowchart illustrating the data output process. Detailed Implementation

[0022] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used to refer to the same elements or elements having the same function, and repeated descriptions are omitted.

[0023] [Power conversion device]

[0024] Figure 1 The power conversion device 1 shown is a device that supplies drive power to the equipment. The equipment has a motor 5 and a drive object of the motor 5, and the power conversion device 1 supplies drive power to the motor 5. The equipment can be any equipment as long as it has a motor 5 and a drive object of the motor 5. Specific examples of the equipment include a wide variety of devices such as fans, pumps, compressors, conveyors, and coolers.

[0025] Motor 5 can be a rotary electric motor or a linear electric motor. Motor 5 can be an induction motor or a synchronous motor. Motor 5 can be an AC motor or a DC motor. Motor 5 can be a fixed coil type with coils on the stator or a movable coil type with coils on the mover.

[0026] The power conversion device 1 converts the power from the power source 3 into drive power to supply the motor 5. The power source 3 can be either AC or DC. Specific examples of the power source include a three-phase AC power system or a three-phase AC uninterruptible power supply. When the motor 5 is an AC motor, the drive power is AC; when the motor 5 is a DC motor, the drive power is DC. As an example, both the power source 3 and the drive power are three-phase AC.

[0027] For example, the power conversion device 1 includes a power conversion circuit 10 and a control circuit 100. The power conversion circuit 10 performs power conversion between the power from the power source 3 (primary power) and the drive power (secondary power). The power conversion circuit 10 is, for example, a voltage-type inverter that applies a drive voltage according to a voltage command to the motor 5.

[0028] For example, the power conversion circuit 10 includes: a converter circuit 11 (rectifier circuit), a smoothing capacitor 12, an inverter circuit 13, and a current sensor 14. The converter circuit 11, for example, is a diode bridge circuit or a pulse width modulation (PWM) converter circuit, performing power conversion between the power from the power source 3 (primary-side power) and DC power (secondary-side power). The smoothing capacitor 12 smooths the aforementioned DC power. The inverter circuit 13 performs power conversion between the aforementioned DC power (primary-side power) and the aforementioned drive power (secondary-side power).

[0029] For example, the inverter circuit 13 has multiple switching elements 15, and the aforementioned power conversion is performed by switching the multiple switching elements 15 on / off. The switching elements 15 are, for example, power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) or IGBTs (Insulated Gate Bipolar Transistors), which are switched on / off according to a gate drive signal.

[0030] The current sensor 14 detects the current flowing between the inverter circuit 13 and the motor 5. For example, the current sensor 14 can be configured to detect the current of all three phases (U phase, V phase, and W phase) of a three-phase AC circuit, or it can be configured to detect the current of any two phases of the three-phase AC circuit. As long as zero-phase current is not generated, the sum of the currents of the U phase, V phase, and W phase is zero. Therefore, even when detecting the current of two phases, information about the current of all phases can be obtained.

[0031] The configuration of the power conversion circuit 10 shown above is merely an example; it can be modified in any way as long as drive power can be supplied to the motor 5. For example, the power conversion circuit 10 can be a current-source inverter. The current-source inverter outputs drive current to the motor 5 according to the current command. The power conversion circuit 10 can also be a matrix converter circuit that performs bidirectional power conversion between power supply and drive power without DC conversion. When the power supply is DC power, the power conversion circuit 10 may not have a converter circuit 11. The power conversion circuit 10 can also be a thyristor Leonard circuit.

[0032] Control circuit 100 controls power conversion circuit 10 to supply drive power to motor 5. For example, control circuit 100 controls power conversion circuit 10 to apply a drive voltage to motor 5 according to a voltage command. The voltage command may include, for example, the magnitude and phase of the voltage command vector.

[0033] The control circuit 100 is configured to perform the following: repeatedly acquiring data sets related to the state of the power conversion circuit 10 and accumulating them in a ring buffer at a predetermined buffer period; generating a trigger signal when the state of a predetermined monitored object meets a predetermined condition; and storing multiple data sets accumulated in the ring buffer in a data storage unit during the period of the object being stored, including the time before the generation time of the trigger signal, when the trigger signal is generated.

[0034] For example, the control circuit 100 has the following functional configurations (hereinafter referred to as "functional blocks"): a power conversion control unit 111, a ring buffer 112, a data storage unit 113, a status monitoring unit 121, a buffer data storage unit 114, a data copying unit 115, and a data output unit 116.

[0035] The power conversion control unit 111 controls the power conversion circuit 10 to apply a drive voltage according to the voltage command to the motor 5. For example, the power conversion control unit 111 repeatedly performs the following operations in a predetermined control cycle: generating a voltage command according to the control command obtained from the upper controller 200, the operation input to the input device 198 (described later), or the signal input (e.g., an analog voltage signal) to the external input terminal 199, and switching the on / off state of multiple switching elements 15 to apply a drive voltage according to the voltage command to the motor 5.

[0036] As an example, the power conversion control unit 111 obtains a speed command (frequency command) from the host controller 200, calculates a current command in a manner that minimizes the deviation between the speed command and the operating speed of the motor 5, and calculates a voltage command for outputting a drive current to the motor 5 according to the current command. The operating speed of the motor 5 can be a detected value obtained from a sensor or a speed estimate.

[0037] The estimated speed value is calculated, for example, based on the drive voltage applied to the motor 5 by the power conversion circuit 10 and the drive current output from the power conversion circuit 10 to the motor 5. The drive current used for calculating the estimated speed value is, for example, the detection value of the current sensor 14. The drive voltage used for calculating the estimated speed value can be the voltage command from the previous control cycle or the detection value obtained from the voltage sensor.

[0038] The power conversion control unit 111 can also obtain a drive force command (e.g., a torque command) from the host controller 200, and calculate a current command in a manner that makes the drive force command consistent with the drive force of the motor 5 (the drive force (e.g., torque) transmitted from the motor 5 to the driven object 4), and calculate a voltage command for outputting a drive current according to the current command to the motor 5. The drive force can be calculated based on the detection value obtained from the current sensor, or it can be estimated based on a speed estimate. The speed estimate is calculated, for example, based on the drive voltage applied to the motor 5 by the power conversion circuit 10 and the drive current output to the motor 5 by the power conversion circuit 10. The power conversion control unit 111 can also be configured to diagnose whether there is an abnormality in the power conversion circuit 10, and issue an alarm signal if an abnormality in the power conversion circuit 10 is sensed. The host controller 200 is, for example, a programmable logic controller.

[0039] The ring buffer 112 temporarily stores a predetermined number of datasets (hereinafter referred to as the "bufferable number") in sequence. The bufferable number is determined by the capacity of the ring buffer 112 and the number of datasets stored. Once the number of stored datasets reaches the bufferable number, the ring buffer 112 deletes the oldest dataset and stores the new dataset. For example, the ring buffer 112 is a buffer in which multiple storage areas are logically arranged in a ring. Each storage area stores one dataset. After the entire storage area of ​​the ring buffer 112 has stored datasets, the oldest dataset is overwritten by the newest dataset. The data storage unit 113 is a storage unit with a larger storage capacity than the ring buffer 112. The buffered data accumulation unit 114 repeatedly acquires a dataset related to the state of the power conversion circuit 10 and stores it in the ring buffer 112 at a predetermined buffering period.

[0040] The dataset includes at least one data item related to the state of the power conversion circuit 10. Specific examples of data items include, in addition to speed commands, motor 5 operating speed, drive force commands, motor 5 drive force, current commands, and current detection values, signal inputs to external input terminals 199 (e.g., analog voltage signals). An appropriate buffer period is set to obtain data with sufficient granularity for parsing data during anomalies. For example, the buffer period is 0.25 to 10 ms.

[0041] When the state of the monitored object meets specified conditions, the state monitoring unit 121 generates a trigger signal. For example, when the state of the power conversion circuit 10 meets specified conditions, the state monitoring unit 121 generates a trigger signal. Specific examples of these conditions include: the driving force is greater than a specified threshold; the driving current is greater than a specified threshold; the amplitude of the driving force is greater than a specified threshold; the amplitude of the driving current is greater than a specified threshold; the deviation between the speed command and the operating speed of the motor 5 (hereinafter referred to as "speed deviation") is greater than a specified threshold, etc. The judgment time point for whether the speed deviation is greater than the specified threshold can also be further determined. For example, the judgment time point for whether the speed deviation is greater than the specified threshold can be set as the time point after a specified time has elapsed since the motor 5 was started. The trigger signal can be a digital signal or an analog signal.

[0042] It should be noted that the monitored object is not limited to the power conversion circuit 10. Specific examples of other monitored objects include instructions from the host controller 200, operational inputs to the input device 198 (described later), and signal inputs to the external input terminal 199. For example, the status monitoring unit 121 may generate a trigger signal when the instruction from the host controller 200 includes a data save instruction. Alternatively, the status monitoring unit 121 may generate a trigger signal when the operational input to the input device 198 includes a data save instruction. Or, the status monitoring unit 121 may generate a trigger signal when the signal input to the external input terminal 199 includes a data save instruction.

[0043] Alternatively, the state monitoring unit 121 may generate a trigger signal when any one of the multiple conditions is met in the state of the power conversion circuit 10. In this case, the state monitoring unit 121 may generate multiple trigger signals corresponding to the multiple conditions in a manner that indicates which of the multiple conditions has been met.

[0044] When a trigger signal is generated, the data copying unit 115 stores multiple datasets accumulated in the ring buffer 112 during the storage of objects including the time before the generation of the trigger signal in the data storage unit 113.

[0045] The data copying unit 115 may also store multiple datasets accumulated in the ring buffer 112 during the storage period, including the time after the generation of the trigger signal, in the data storage unit 113. For example, when the entire storage area of ​​the ring buffer 112 is filled with datasets, the data copying unit 115 continues to accumulate data into the ring buffer 112 by the buffer data accumulation unit 114 until a predetermined period (hereinafter referred to as the "post-trigger period") has elapsed. Then, the accumulation of data into the ring buffer 112 by the buffer data accumulation unit 114 is temporarily interrupted, and the contents of the ring buffer 112 are stored in the data storage unit 113. The length of the storage period is equal to the bufferable period of the ring buffer 112. The bufferable period is the period of the bufferable quantity multiplied by the buffering period. The post-trigger period is shorter than the bufferable period. Therefore, the multiple datasets accumulated in the ring buffer 112 after the post-trigger period include datasets accumulated during the period before the generation of the trigger signal (hereinafter referred to as the "pre-trigger period").

[0046] The data output unit 116 outputs multiple datasets stored in the data storage unit 113 to the host controller 200 or the display device 197 (described later). The data output unit 116 can repeatedly output multiple datasets at a predetermined output cycle, or it can output multiple datasets according to an output request. The data output unit 116 obtains an output request, for example, from the host controller 200 or the input device 198 (described later).

[0047] The control circuit 100 may also include a period setting unit 122. The period setting unit 122 sets the length and buffer period of the period preceding the generation time of the trigger signal within the target period (the aforementioned pre-trigger period) based on user input. As described above, the length of the target period is equal to the length of the bufferable period, and the bufferable period is determined based on the buffer period. Therefore, once the pre-trigger period and the buffer period are determined, the post-trigger period is determined. Similarly, once the post-trigger period and the buffer period are determined, the pre-trigger period is determined, and once the pre-trigger period and the post-trigger period are determined, the buffer period is determined. Therefore, the user input for setting the pre-trigger period and the buffer period may not necessarily be an input directly specifying the pre-trigger period and the buffer period, but may be an input specifying the post-trigger period and the buffer period, or an input specifying both the pre-trigger period and the post-trigger period. Furthermore, the user input for setting the pre-trigger period and the buffer period may also be an input specifying the percentage (%) of the pre-trigger period within the bufferable period. Based on this input, since the percentage of the post-trigger period within the bufferable period is also determined, the buffer period is also determined.

[0048] The period setting unit 122 can acquire user input specifying a pre-trigger period and automatically set the post-trigger period based on the bufferable period and the pre-trigger period. The period setting unit 122 can also acquire user input specifying a post-trigger period and automatically set the pre-trigger period based on the bufferable period and the post-trigger period. The period setting unit 122 can also automatically set the pre-trigger period and the post-trigger period based on the type of trigger signal.

[0049] The control circuit 100 may also include a log data accumulation unit 123 and an offset value calculation unit 124. The log data accumulation unit 123 repeatedly acquires a dataset related to the state of the power conversion circuit 10 at a log cycle longer than the buffer cycle and stores it in the data storage unit 113.

[0050] The dataset (hereinafter referred to as the "long-cycle dataset") stored in the data storage unit 113 by the log data accumulation unit 123 includes at least one data item related to the state of the power conversion circuit 10. The composition of the long-cycle dataset is at least partially the same as the composition of the dataset (hereinafter referred to as the "short-cycle dataset") stored in the ring buffer 112 by the buffer data accumulation unit 114. For example, the number and types of data items in the long-cycle dataset are the same as those in the short-cycle dataset. However, the composition of the long-cycle dataset may also differ from that of the short-cycle dataset. For example, the number of data items in the short-cycle dataset may be greater than the number of data items in the long-cycle dataset.

[0051] For example, when a trigger signal is generated, the log data accumulation unit 123 interrupts the storage of long-cycle datasets to the data storage unit 113. After the data replication unit 115 stores multiple short-cycle datasets in the data storage unit 113, the log data accumulation unit 123 resumes storing long-cycle datasets to the data storage unit 113.

[0052] Data storage unit 113 stores multiple long-period datasets and multiple short-period datasets in time sequence. For example, data storage unit 113 stores multiple long-period datasets and multiple short-period datasets in the order they are stored in data storage unit 113.

[0053] The log period is set appropriately to obtain data with sufficient granularity to grasp the tendency under normal conditions. For example, the log period is 0.1 to 10 seconds. The log data accumulation unit 123 can also limit the period during which long-period datasets can be stored in the data storage unit 113 (hereinafter referred to as "storable period") to a series of periods that will not be interrupted by the generation of a trigger signal. For example, if the series of periods exceeds the storable period, the log data accumulation unit 123 can overwrite the oldest long-period dataset in the series of periods with the latest long-period dataset.

[0054] It should be noted that, as an example of limiting the retrievable period, the log data accumulation unit 123 can also limit the number of long-period datasets that can be stored within the aforementioned series of periods (hereinafter referred to as the "retrievable quantity"). The retrievable period is equivalent to the retrievable quantity multiplied by the log period; therefore, by limiting the retrievable quantity, the retrievable period is also limited. The retrievable period is longer than the aforementioned bufferable period. For example, the retrievable period can be 2 to 100 times the bufferable period, or 10 to 80 times, or 20 to 70 times, or 30 to 60 times.

[0055] The offset calculation unit 124 calculates an offset value that represents the relationship between the start time of the aforementioned storage period and the storage time of the long-cycle dataset based on the log data accumulation unit 123. The offset calculation unit 124 calculates the offset value based on the generation time of the trigger signal, the time immediately preceding that generation time when the log data accumulation unit 123 stores the long-cycle dataset in the data storage unit 113, and the length of the period before the trigger.

[0056] Figure 2 This is a time series diagram illustrating the relationship between the storage time, the start time of the saved object period, the trigger generation time, and the offset value of a long-period dataset. The right direction of the diagram indicates the direction of time progression. Time points t01, t02, t03, t04, and t05 are the storage times of the long-period data, and these intervals are the log period CT1.

[0057] exist Figure 2 In the process, a trigger signal is generated at time t11 immediately following time t05. Therefore, time t05 is the time when the log data accumulation unit 123 stores the long-period dataset in the data storage unit 113 immediately before the trigger signal generation time t11. The offset value calculation unit 124 calculates the start time t21 of the object storage period T10 based on the length of the pre-trigger period T11 and the trigger signal generation time t11, and calculates the offset value T12 using the time difference (t05-t21) between time t21 and time t05.

[0058] The data replication unit 115 can establish corresponding storage in the data storage unit 113 of multiple long-period datasets and multiple short-period datasets accumulated in the data storage unit 113 through the log data accumulation unit 123. For example, the data replication unit 115 establishes corresponding storage in the data storage unit 113 of multiple long-period datasets, offset values, and multiple short-period datasets.

[0059] For example, the data copying unit 115 establishes a correspondence between the offset value and the storage time of the long-period dataset that serves as the calculation basis for the offset value, and stores multiple short-period datasets in the data storage unit 113. Thus, multiple long-period datasets and multiple short-period datasets can be arranged in the same temporal order. The data copying unit 115 can also further establish a correspondence between setting parameters such as the pre-trigger period and the post-trigger period, and store multiple short-period datasets in the data storage unit 113.

[0060] The data output unit 116 can output multiple datasets, including multiple long-term datasets and multiple short-term datasets, to the host controller 200 or the display device 197 (described later). This allows for the simultaneous display of long-term trend data represented by the multiple long-term datasets and short-term detailed data represented by the multiple short-term datasets.

[0061] Figure 3 This is a block diagram illustrating the hardware configuration of the control circuit 100. For example... Figure 3 As shown, the control circuit 100 includes: one or more processors 191, a memory 192, a storage device 193, a communication port 194, a drive circuit 195, and an input / output port 196. The storage device 193 is, for example, a storage medium readable by a computer, such as a non-volatile semiconductor memory. The storage device 193 stores a program for causing the control circuit 100 to perform the following steps: controlling the power conversion circuit 10 to supply drive power to the motor 5; repeatedly acquiring data sets related to the state of the power conversion circuit 10 at predetermined buffer cycles and accumulating them in a ring buffer 112; and, upon the generation of a trigger signal, storing multiple data sets accumulated in the ring buffer 112 during a pre-trigger period (at least including the time before the trigger signal is generated) in a data storage unit 113. The storage device 193 is, for example, a hard disk or a non-volatile memory.

[0062] Memory 192 temporarily stores the program loaded from the storage medium of storage device 193 and the calculation results obtained by processor 191. Memory 192 is, for example, random access memory. Processor 191 and memory 192 cooperate to execute the program, thereby forming the functional blocks of control circuit 100. Communication port 194 communicates with the host controller 200 according to instructions from processor 191. Drive circuit 195 outputs drive signals to inverter circuit 13 to switch the switching element 15 on / off according to instructions from processor 191. Input / output port 196 inputs / outputs electrical signals with current sensor 14, display device 197, input device 198, and external input terminal 199 according to instructions from processor 191.

[0063] Display device 197 includes, for example, a liquid crystal panel or an organic electroluminescent (EL) panel, displaying an interface image according to instructions from processor 191. Input device 198 includes, for example, input keys, receiving input (key input) to the input keys. Display device 197 and input device 198 can be separately configured from the main body of power conversion device 1, and can communicate with the main body via wired or wireless means. In this case, display device 197 and input device 198 can be integrated as a keypad, or in the case of a keypad, display device 197 and input device 198 can be integrated as a touch panel. External input terminal 199 is located outside power conversion device 1, receiving electrical signals (e.g., analog voltage signals) from the outside.

[0064] It should be noted that the aforementioned ring buffer 112 and data storage unit 113 are disposed within a medium fixed in the power conversion device 1. For example, the ring buffer 112 may be disposed in the memory 192 or the storage device 193. The data storage unit 113 may be disposed in a portable medium removable from the media drive fixed to the power conversion device 1. The data storage unit 113 may also be disposed in a medium fixed to the aforementioned keypad. Furthermore, the data storage unit 113 may also be disposed in a portable medium removable from the media drive fixed to the aforementioned keypad. Specific examples of portable media include SD (Secure Digital) cards, USB (Universal Serial Bus) memory, etc.

[0065] The control circuit 100 is not necessarily limited to being configured with various functions through a program. For example, the control circuit 100 may also be configured with at least some of the functions through dedicated logic circuits or an ASIC (Application Specific Integrated Circuit) that integrates such dedicated logic circuits.

[0066] The above is an example of a control device, illustrating a power conversion device 1, which includes: a control unit (power conversion control unit 111) that controls the controlled object (power conversion circuit 10 and motor 5); a buffer data accumulation unit 114 that repeatedly acquires data sets related to the state of the controlled object at a predetermined buffer period and stores them in a ring buffer 112; a state monitoring unit 121 that generates a trigger signal when the state of the monitored object meets predetermined conditions; and a data copying unit 115 that, upon generating a trigger signal, stores multiple data sets accumulated in the ring buffer 112 during the storage period, including the time before the generation of the trigger signal, in a data storage unit 113. Alternatively, a control unit that configures the power conversion control unit 111 and the power conversion circuit 10 to control the motor 5 could also be considered.

[0067] The data storage unit 113 may not necessarily be located within the control device, or it may be located outside the control device. For example, the data storage unit 113 may be located within the host controller 200, or it may be located on an external storage device capable of communicating with the control device via wired or wireless means. Furthermore, the data storage unit 113 may also be located on a keypad used to operate the control device. Storing multiple datasets in the data storage unit 113 includes sending them to the host controller 200, an external storage device, or the keypad, thereby enabling the storage of multiple datasets in the data storage unit 113 via the host controller 200, the external storage device, or the keypad. The data storage unit 113 may also be located on a removable medium such as an SD card.

[0068] The configuration, including a control unit, a buffer data storage unit, a status monitoring unit, and a data copying unit, can also be applied to control devices different from power conversion devices (e.g., servo controllers). The control unit in a servo controller at least includes a control arithmetic unit that generates instructions, and the controlled object in a servo controller at least includes a servo motor. The drive circuit that supplies drive power to the servo motor based on instructions can be considered to be included in the controlled object, or it can be considered to be included in the control unit.

[0069] [Electricity conversion process]

[0070] Next, as an example of a data accumulation method, a power conversion process including a data accumulation process is illustrated. This process includes: a power conversion control process, a buffered data accumulation process, a log data accumulation process, and a data output process. The buffered data accumulation process, the log data accumulation process, the data output process, and the power conversion control process are executed in parallel. Each process is illustrated in detail below.

[0071] (Power conversion control process)

[0072] This process includes generating a trigger signal when the state of the power conversion circuit 10 meets specified conditions. For example... Figure 4 As shown, the control circuit 100 first executes steps S01, S02, and S03. In step S01, the power conversion control unit 111 obtains control commands such as speed commands and torque commands from the host controller 200. In step S02, the power conversion control unit 111 acquires the detection value of the current sensor 14 as current information. In step S03, the status monitoring unit 121 confirms whether the status of the power conversion circuit 10 meets the above conditions.

[0073] If, in step S03, the state of the power conversion circuit 10 is determined to meet the conditions, the control circuit 100 executes step S04. In step S04, the state monitoring unit 121 sets the trigger signal to ON (generates). If, in step S03, the state of the power conversion circuit 10 is determined to not meet the conditions, the control circuit 100 executes step S05. In step S05, the state monitoring unit 121 sets the trigger signal to OFF (does not generate).

[0074] Next, the control circuit 100 executes steps S06, S07, and S08. In step S06, the power conversion control unit 111 generates a voltage command based on the aforementioned control command and current information. In step S07, the power conversion control unit 111 begins switching the multiple switching elements 15 on / off to apply a drive voltage according to the voltage command to the motor 5. In step S08, the power conversion control unit 111 waits for the control cycle to elapse.

[0075] The control circuit 100 repeats the above process. The above process can be modified appropriately. For example, steps S03, S04, and S05 can be executed after step S07.

[0076] (Buffered data accumulation process)

[0077] The process includes: repeatedly acquiring short-cycle datasets at a predetermined buffer period and accumulating them in a ring buffer 112; and, in the event of a trigger signal, storing multiple short-cycle datasets accumulated in the ring buffer 112 during a pre-trigger period of object storage, including at least the time before the trigger signal is generated, in a data storage unit 113.

[0078] like Figure 5 As shown, the control circuit 100 first executes steps S11 and S12. In step S11, the buffer data accumulation unit 114 waits for the buffer cycle to elapse. In step S12, the data copying unit 115 confirms whether the trigger signal is on (whether it has been generated).

[0079] If it is determined in step S12 that the trigger signal is not activated, the control circuit 100 executes step S13. In step S13, the buffer data accumulation unit 114 stores the short-cycle dataset in the ring buffer 112. Thereafter, the control circuit 100 returns to step S11. Subsequently, before the trigger signal is generated, the short-cycle dataset is repeatedly stored in the ring buffer 112 during the buffer cycle.

[0080] If the trigger signal is determined to be on in step S12, the control circuit 100 executes steps S14 and S15. In step S14, the buffer data accumulation unit 114 stores the short-cycle dataset in the ring buffer 112. In step S15, the data copying unit 115 checks whether the post-trigger period has elapsed since the moment the trigger signal was generated.

[0081] If it is determined in step S15 that the post-trigger period has not elapsed, the control circuit 100 executes step S16. In step S16, the buffer data accumulation unit 114 waits for the buffer period to elapse. Thereafter, the control circuit 100 returns to step S14. Subsequently, short-cycle datasets are repeatedly stored in the ring buffer 112 during the buffer period before the post-trigger period elapses.

[0082] If it is determined in step S15 that the period following the trigger has elapsed, the control circuit 100 executes steps S17 and S18. In step S17, the offset value calculation unit 124 calculates the offset value based on the time of generation of the trigger signal, the time immediately preceding that time when the log data accumulation unit 123 stores the long-period dataset in the data storage unit 113, and the length of the period before the trigger. In step S18, the data copying unit 115 stores the short-period dataset, the offset value, and the trigger setting parameters in the data storage unit 113 in a corresponding manner with the long-period dataset. The control circuit 100 repeats the above process.

[0083] (Log data accumulation process)

[0084] This process involves repeatedly acquiring a dataset related to the state of the power conversion circuit 10 at log cycles longer than the buffer cycle and storing it in the data storage unit 113. For example... Figure 6 As shown, the control circuit 100 first executes step S21. In step S21, the log data accumulation unit 123 confirms whether the trigger signal is on.

[0085] If the trigger signal is determined to be on in step S21, the control circuit 100 executes step S22. In step S22, the log data accumulation unit 123 checks whether a log cycle has elapsed. If it is determined in step S22 that a log cycle has not elapsed, the control circuit 100 returns to step S21. Afterward, the control circuit 100 waits for the trigger signal to become on and for a log cycle to elapse.

[0086] If a log cycle has elapsed in step S22, the control circuit 100 executes step S23. In step S23, the log data accumulation unit 123 stores the long-cycle dataset in the data storage unit 113. Afterward, the control circuit 100 returns to step S21. Then, until a trigger signal is activated, the long-cycle dataset is repeatedly stored in the data storage unit 113 during the log cycle.

[0087] If, in step S21, it is determined that the trigger signal is not disconnected, the control circuit 100 executes step S24. In step S24, the log data accumulation unit 123 waits for the data copying unit 115 to store multiple short-cycle datasets in the data storage unit 113. Therefore, the storage of long-cycle datasets by the log data accumulation unit 123 is interrupted after the trigger signal is generated but before the multiple short-cycle datasets are stored. Afterwards, the control circuit 100 executes step S22. Therefore, the storage of long-cycle datasets by the log data accumulation unit 123 resumes. The control circuit 100 repeats the above process.

[0088] (Data output process)

[0089] This process includes outputting multiple datasets stored in the data storage unit 113 to the host controller 200 or the display device 197, etc. The following example illustrates the process of outputting multiple datasets based on an output request. Figure 7 As shown, the control circuit 100 executes steps S31, S32, and S33. In step S31, the data output unit 116 waits for an output request from the host controller 200 or the input device 198.

[0090] In step S32, based on the multiple datasets stored in the data storage unit 113, the data output unit 116 generates output data. For example, the data output unit 116 generates output data that arranges multiple long-period datasets and multiple short-period datasets in the same time sequence. In step S33, the data output unit 116 outputs the output data to the host controller 200 or the display device 197, etc. The control circuit 100 repeats the above process.

[0091] [Effects of this implementation method]

[0092] As described above, the power conversion device 1 includes: a power conversion circuit 10 that performs power conversion between primary power and secondary power; a buffer data accumulation unit 114 that repeatedly acquires data sets related to the state of the power conversion circuit 10 and stores them in a ring buffer 112 at a predetermined buffer period; a state monitoring unit 121 that generates a trigger signal when the state of a predetermined monitored object meets predetermined conditions; and a data copying unit 115 that, when a trigger signal is generated, stores multiple data sets accumulated in the ring buffer 112 during the storage period, including the time before the generation time of the trigger signal, in a data storage unit 113.

[0093] The storage of multiple datasets (the aforementioned short-cycle datasets) accumulated during the buffer period in the data storage unit 113 is limited to the case where a trigger signal is generated. This shortens the buffer period while suppressing the amount of data stored in the data storage unit 113. Furthermore, storing multiple short-cycle datasets accumulated during the storage period, including the time preceding the generation of the trigger signal, in the data storage unit 113 allows for detailed analysis of data changes prior to the generation of the trigger signal. Therefore, the power conversion device 1 is effective in balancing resource conservation in data accumulation with detailed data analysis.

[0094] Alternatively, the state monitoring unit 121 may generate a trigger signal when the state of the power conversion circuit 10 meets specified conditions. In this case, multiple short-cycle datasets can be stored in the data storage unit 113 during periods when the need for state analysis of the power conversion circuit 10 is high.

[0095] The data copying unit 115 can also store multiple datasets accumulated in the ring buffer 112 during the storage of objects, including the time after the generation of the trigger signal, in the data storage unit 113. In this case, the data changes after the generation of the trigger signal can be analyzed in detail.

[0096] The power conversion device 1 may also include a period setting unit 122, which sets the length of the period before the generation time of the trigger signal in the target period and the buffer period based on user input. In this case, data corresponding to the frequency of data changes that are to be analyzed can be accumulated.

[0097] The power conversion device 1 may also include a log data accumulation unit 123, which repeatedly stores at least one long-cycle dataset related to the state of the power conversion circuit 10 in a data storage unit 113 at a log cycle longer than the buffer cycle. The data copying unit 115 stores multiple long-cycle datasets accumulated in the data storage unit 113 by the log data accumulation unit 123 and multiple datasets corresponding to each other in the data storage unit 113. In this case, data sets can be accumulated over a longer period of time while conserving data accumulation resources.

[0098] The power conversion device 1 may also include an offset value calculation unit 124, which calculates an offset value representing the relationship between the start time of the storage period and the storage time of the long-period dataset based on the log data accumulation unit 123. The data copying unit 115 stores multiple long-period datasets, the offset value, and the multiple datasets in the data storage unit 113. In this case, the relationship between the time-varying changes of multiple long-period datasets and the time-varying changes of multiple short-period datasets can be appropriately represented.

[0099] The offset calculation unit 124 can also calculate the offset value based on the time when the trigger signal is generated, the time when the log data accumulation unit 123 immediately preceding that time stores the long-period dataset in the data storage unit 113, and the length of the period before the time the trigger signal is generated during the storage period. In this case, the offset value can be calculated simply.

[0100] Alternatively, upon the generation of a trigger signal, the log data accumulation unit 123 interrupts the storage of long-cycle datasets to the data storage unit 113. After the data replication unit 115 stores multiple datasets in the data storage unit 113, the log data accumulation unit 123 resumes the storage of long-cycle datasets to the data storage unit 113. In this case, data accumulation resources can be further conserved.

[0101] The embodiments have been described above, but this disclosure is not necessarily limited to the embodiments described above, and various modifications can be made without departing from its spirit. For example, the above shows an example of a data storage device being assembled into a power conversion device 1, wherein the data storage device includes: a ring buffer 112, a data storage unit 113, a status monitoring unit 121, a buffered data storage unit 114, a data copying unit 115, a data output unit 116, a period setting unit 122, a log data storage unit 123, and an offset value calculation unit 124, but is not limited thereto. The data storage device may also be assembled into other devices separate from the power conversion device 1. For example, the data storage device may also be assembled into a host controller 200.

[0102] Explanation of reference numerals in the attached figures

[0103] 1: Power conversion device;

[0104] 10: Power conversion circuit;

[0105] 112: Ring buffer;

[0106] 113: Data Storage Department;

[0107] 114: Buffer data accumulation section;

[0108] 115: Data Replication Department;

[0109] 121: Condition Monitoring Department;

[0110] 122: Period Setting Department;

[0111] 123: Log data accumulation section;

[0112] 124: Offset value calculation unit.

Claims

1. A power conversion device, the power conversion device comprising: A power conversion circuit performs power conversion between primary and secondary power. The buffer data accumulation unit repeatedly acquires and stores data sets related to the state of the power conversion circuit in a ring buffer at a predetermined buffer period. A log data accumulation unit, which repeatedly stores at least one long-cycle dataset related to the state of the power conversion circuit in a data storage unit at a log cycle longer than the buffer cycle; The status monitoring unit generates a trigger signal when the status of the monitored object meets the specified conditions; and The data copying unit, upon the generation of the trigger signal, continuously accumulates data in the ring buffer by the buffer data accumulation unit for a predetermined period of time. Multiple datasets accumulated in the ring buffer during the storage period, including the time before the generation of the trigger signal and the time after the generation of the trigger signal within the predetermined period, are stored in the data storage unit.

2. The power conversion device according to claim 1, wherein, When the state of the power conversion circuit meets the specified conditions, the state monitoring unit generates the trigger signal.

3. The power conversion device according to claim 1, wherein, The power conversion device also includes a period setting unit, which sets the length of the period before the generation time of the trigger signal in the period of the stored object and the buffer period based on user input.

4. The power conversion device according to claim 1, wherein, The data replication unit establishes a correspondence between the multiple long-cycle datasets accumulated in the data storage unit through the log data accumulation unit and the multiple datasets, and stores them in the data storage unit.

5. The power conversion device according to claim 4, wherein, The power conversion device also includes an offset value calculation unit, which calculates an offset value representing the relationship between the start time of the period during which the object is stored and the storage time of the long-term dataset based on the log data accumulation unit. The data replication unit stores the multiple long-period datasets, the offset values, and the multiple datasets in the data storage unit.

6. The power conversion device according to claim 5, wherein, The offset calculation unit calculates the offset value based on the time when the trigger signal is generated, the time when the log data accumulation unit stores the long-cycle dataset in the data storage unit immediately before the generation time, and the length of the period before the generation time of the trigger signal during the storage period.

7. The power conversion device according to any one of claims 1, 4 to 6, wherein, When the trigger signal is generated, the log data accumulation unit interrupts the storage of the long-cycle dataset to the data storage unit. After the data replication unit stores the multiple datasets in the data storage unit, the log data accumulation unit resumes the storage of the long-cycle dataset to the data storage unit.

8. A control device, the control device comprising: Control department, which controls the controlled objects; The buffer data accumulation unit repeatedly acquires and stores the dataset related to the state of the controlled object in a ring buffer at a predetermined buffer period. A log data accumulation unit, which repeatedly stores at least one long-cycle dataset related to the state of the power conversion circuit in the data storage unit at a log cycle longer than the buffer cycle; The status monitoring unit generates a trigger signal when the status of the monitored object meets the specified conditions; and The data copying unit, upon the generation of the trigger signal, continuously accumulates data in the ring buffer by the buffer data accumulation unit for a predetermined period of time. Multiple datasets accumulated in the ring buffer during the storage period, including the time before the generation of the trigger signal and the time after the generation of the trigger signal within the predetermined period, are stored in the data storage unit.

9. The control device according to claim 8, wherein, When the trigger signal is generated, the log data accumulation unit interrupts the storage of the long-cycle dataset to the data storage unit. After the data replication unit stores the multiple datasets in the data storage unit, the log data accumulation unit resumes the storage of the long-cycle dataset to the data storage unit.

10. A data storage device, the data storage device comprising: The buffer data accumulation section repeatedly acquires and stores the dataset related to the state of the controlled object in a ring buffer at a specified buffer period. A log data accumulation unit, which repeatedly stores at least one long-cycle dataset related to the state of the power conversion circuit in the data storage unit at a log cycle longer than the buffer cycle; The status monitoring unit generates a trigger signal when the status of the monitored object meets the specified conditions; and The data copying unit, upon the generation of the trigger signal, continuously accumulates data in the ring buffer by the buffer data accumulation unit for a predetermined period of time. Multiple datasets accumulated in the ring buffer during the storage period, including the time before the generation of the trigger signal and the time after the generation of the trigger signal within the predetermined period, are stored in the data storage unit.

11. A data accumulation method, the data accumulation method comprising: The system repeatedly acquires and stores the dataset related to the state of the controlled object in a circular buffer at a specified buffer period. At least one long-cycle dataset related to the state of the controlled object is stored in the data storage unit repeatedly with a log cycle longer than the buffer cycle. A trigger signal is generated when the state of the specified monitored object meets the specified conditions; as well as When the trigger signal is generated, the data is continuously accumulated in the ring buffer by the buffer data accumulation unit before a predetermined period, and multiple datasets accumulated in the ring buffer during the storage period including the time before the generation time of the trigger signal and the time after the generation time of the trigger signal and within the predetermined period are stored in the data storage unit.

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