JP2021069171A - Power conversion device - Google Patents

Abstract

To provide a power conversion device with few operational restrictions even when the device includes a daisy-chained communication path.SOLUTION: A power conversion device according to an embodiment includes a power converter with a plurality of converters, and a packet data includes a first area that stores a plurality of pieces of control data for controlling the plurality of converters, a second area that stores identification data for identifying the plurality of converters, and a third area that stores converter data of the converter that has the identification data. The number of pieces of identification data stored in the second area is 1 or more, which is smaller than the number of the plurality of converters.SELECTED DRAWING: Figure 1

Description

An embodiment of the present invention relates to a power conversion device.

There is a power converter that converts power between AC and DC. In power converters installed in power systems, social infrastructure such as railways, factory equipment, etc., the capacity of electric power handled may be increased by multiplexing a plurality of power converters.

A communication path for transmitting and receiving these data is provided between the control device and the power converter in order to transmit a control command to the multiplexed power converter and receive the state from the power converter. In a multiplexed power converter, if a communication path is provided for each converter, a communication path is provided according to the number of converters, and it is necessary to reduce these from the viewpoint of cost, space, and the like.

By configuring the communication path between the control device and each power converter by a daisy chain connection, the communication path between a plurality of power converters can be integrated into one. In a power converter using a communication path connected in a daisy chain, the data to be transmitted is sequentially transferred from the control device to each converter, so that the operation of the power converter is restricted by the period of one cycle of the communication path loop. Will be done.

JP-A-2017-143626

The embodiment provides a power conversion device having less restrictions on operation even if it has a communication path connected in a daisy chain.

The power converter according to the embodiment includes a power converter including a plurality of converters, the packet data includes a first area for storing a plurality of control data for controlling the plurality of converters, and the plurality of converters. It includes a second area for storing identification data for identifying the converter, and a third area for storing the converter data of the converter having the identification data among the plurality of converters. The number of the identification data stored in the second region is 1 or more, which is smaller than the number of the plurality of converters.

In the present embodiment, a power conversion device having less restrictions on operation is realized even if it has a communication path connected in a daisy chain.

It is a schematic block diagram which illustrates the power conversion apparatus which concerns on embodiment. It is a schematic block diagram which illustrates a part of the power conversion apparatus of FIG. It is a schematic diagram which illustrates the packet data transmitted in the power conversion apparatus of FIG. It is a schematic diagram for demonstrating the operation of the power conversion apparatus of embodiment. It is an example of the flowchart for demonstrating the operation of the power conversion apparatus of embodiment. It is a schematic diagram which illustrates the packet data transmitted in the power conversion apparatus of the comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes between the parts, and the like are not necessarily the same as the actual ones. Further, even when the same parts are represented, the dimensions and ratios may be different from each other depending on the drawings.
In addition, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures are designated by the same reference numerals, and detailed description thereof will be omitted as appropriate.

FIG. 1 is a schematic block diagram illustrating the power conversion device according to the embodiment.
As shown in FIG. 1, the power converter 10 of the present embodiment includes a power converter 20 and a control device 50. The power conversion device 10 is connected to the AC system 1 via the AC terminals 21a to 21c. As in this example, the power conversion device 10 may be connected to the AC system 1 via the transformer 2. For example, the AC system 1 can be configured to include a three-phase or single-phase 50 Hz or 60 Hz power supply, load, and AC transmission line. The power conversion device 10 is connected to the DC system 3. The DC system 3 includes, for example, a DC transmission line and the like.

The power conversion device 10 is connected between the AC system 1 and the DC system 3 and can perform bidirectional power conversion.

The power converter 20 includes a unit arm 22 corresponding to each phase of three-phase alternating current. The unit arm 22 is connected in series between the DC terminals 21d and 21e to form a leg. The unit arm 22 is provided corresponding to the UP phase, VP phase, WP phase on the high potential side and the UN phase, VN phase, and WN phase on the low potential side.

A transformer 24 is connected in series to the unit arm 22 which is connected in series between the DC terminals 21d and 21e. A buffer reactor may be connected instead of the transformer 24.

The unit arm 22 includes a unit converter (cell) 30 connected in cascade. The number of cells 30 may be one or more per unit arm 22, but in the following, it is assumed that C cells are connected in series (C is an integer of 2 or more).

Here, an example of a modular multilevel converter (MMC) in which a plurality of unit converters are connected in a cascade among the multiplexing control methods will be described, but the communication method described below is not limited to the MMC. It can be applied to the power converter of the multiplexing control method. For example, the applied power converter may include power converters connected in parallel.

The control device 50 includes a control circuit 52. The control circuit 52 is connected to the power converter 20 via a communication path 60. In this example, the communication path 60 is provided for each unit arm 22. In the figure, in order to avoid complication, the communication path 61 corresponding to the unit arm 22 corresponding to the UN phase is shown to be interconnected with the cell 30. For the other unit arms 22, in the UP phase, it is shown that the “a” on the control device 50 side and the “a” on the cell 30 side are connected to each other. Similarly, in the VP phase, the "b" on the control device 50 side and the "b" on the cell 30 side are interconnected, and in the WP phase, the "c" on the control device 50 side and the "c" on the cell 30 side are connected. They are interconnected. The same applies to each phase on the low potential side. In the VN phase, the “d” on the control device 50 side and the “d” on the cell 30 side are interconnected, and in the WN phase, the “e” on the control device 50 side. And "e" on the cell 30 side are connected to each other.

In the communication paths 60 and 61, the control circuit 52 on the control device 50 side and the control circuit on the cell 30 side are similarly connected in a loop by a daisy chain connection for each unit arm 22. Hereinafter, the UN phase and the communication path 61 will be described, but the same applies to the other phases and the communication path 60.

In the UN phase communication path 61, the control circuit 52 on the control device 50 side is connected to the control circuit 36 of the cell 30 (denoted as cell 1 in FIG. 1) on the highest potential side. The control circuit 36 of the cell 30 on the highest potential side is connected to the control circuit 36 of the cell 30 (denoted as cell 2 in FIG. 1) which is cascade-connected to the cell 30 (cell 1). Similarly, the cells 30 are connected to each other by the communication path 61 toward the low potential side. The control circuit 36 of the cell 30 on the lowest potential side (denoted as cell C in FIG. 1) is connected to the control circuit 52 on the control device 50 side. That is, these are daisy-chained by forming a loop of the communication path 61 in the order of control device 50 → cell 1 → cell 2 → ... → cell C → control device 50.

The number of cells 30 included in one daisy chain connection is the number of unit arms 22 in the above, but an appropriate number can be arbitrarily set. For example, one loop may include cells 30 of UP phase and UN phase, all cells 30 may be daisy-chained in one loop, and so on. Alternatively, one phase may be divided into a plurality of loops.

Packet data corresponding to the communication paths 60 and 61 is transmitted to the communication paths 60 and 61. The packet data includes data for controlling the operation of the cell 30, data for identifying the cell 30, and data indicating the state of the cell 30, which will be described in detail later.

FIG. 2 is a schematic block diagram illustrating a part of the power conversion device of FIG.
As shown in FIG. 2, the cell 30 includes terminals 31a and 31b. The cell 30 is connected to another cell 30 or the like by terminals 31a and 31b. The cell 30 includes a main circuit 32, a main circuit feeding unit 34, a control circuit 36, and a gate drive circuit 35. The main circuit feeding unit 34 is connected to the main circuit 32, and is fed from the main circuit 32 to generate a power source for the control circuit 36, the gate drive circuit 35, and the like. The control circuit 36 and the gate drive circuit 35 operate by supplying electric power from the main circuit feeding unit 34. The control circuit 36 acquires its own control data from the packet data transmitted through the communication path 61, and generates a gate drive signal based on the acquired control data.

The main circuit 32 includes a switching element 32a, a diode 32b, and a capacitor 32c. The switching element 32a is a self-extinguishing semiconductor element. Two switching elements 32a are connected in series.

The diode 32b is a freewheeling diode. The two diodes 32b are connected in antiparallel to each of the switching elements 32a connected in series.

The capacitor 32c is connected in parallel to two switching elements 32a connected in series.

Although not shown, each cell 30 has a voltage detector that detects the cell voltage across the capacitor 32c and the voltage between the terminals 31a and 31b, and a current detector that detects the input / output current. The voltage or current detected by the detector or the current detector is supplied to the control device 50.

In this example, the MMC uses cells 30 having a half-bridge configuration, but of course, the cells may have a full-bridge configuration and all cells may be replaced with a full-bridge configuration. Further, in this example, each cell 30 has a main circuit feeding unit 34, and a part of the energy of the capacitor 32c is used to supply electric power to its own control circuit or the like, but from the outside of the cell. Of course, the method of supplying power to each cell may be used.

The control circuit 52 of the control device 50 processes data acquired from the host control system (not shown), other parts of the control device 50, and data acquired from each cell 30, and controls for each cell 30. Generate data. The control data is data for controlling the operation of each cell 30. The control data includes data related to a control command such as a gate drive pulse for driving the switching element in each cell 30.

The data acquired from the host control system is, for example, a command value of DC power. The data acquired from other parts of the control device 50 includes, for example, voltage and current data of the system to which the power conversion device 10 is connected, and may include data related to an abnormality such as a ground fault. ..

The control circuit 52 generates a counter set value. The counter set value is data for identifying the cell 30, and is used for determining whether or not the cell 30 writes its own data in the packet data that circulates in the daisy-chained loop. Each cell 30 looks at the counter set value and determines whether or not to write its own data to the packet data.

The control circuit 36 of each cell 30 acquires its own control data from the packet data received from the control device 50. Each control circuit 36 sets, for example, the operation of the main circuit 32 based on the acquired control data.

The control circuit 36 of each cell 30 confirms the counter set value and determines whether or not its own data should be written to the packet data based on the counter set value.

When the counter set value is a value for writing its own data to the packet data, the control circuit 36 of each cell 30 transmits the updated packet data to the next cell 30 after writing its own data to the packet data. To do. When the counter set value is a value at which it is not necessary to write its own data, the control circuit 36 does nothing and transmits the packet data to the next cell 30 as it is.

Each cell 30 and the control device 50 are isolated from each other. Therefore, the communication paths 60 and 61 of each phase are preferably configured by an optical fiber cable. When the communication paths 60 and 61 are composed of optical fibers, the control circuits 52 and 36 include photoelectric conversion circuits, respectively, and transmit and receive data via the photoelectric conversion circuits.

FIG. 3 is a schematic diagram illustrating packet data transmitted in the power conversion device of FIG.
As shown in FIG. 3, the packet data 100 includes an area (first area) 102 containing control data, an area (second area) 104 containing counter set values, and an area (third area) 106 containing converter data. Each area is included. The control data is a control command containing data of gate drive pulses for each cell 30, as described above. The control data 1 for the cell 30 on the highest potential side (cell 1 in FIGS. 1 and 3) is stored in the corresponding region. The control data 2 for the cell on the low potential side of the cell 30 (cell 2 in FIGS. 1 and 3) is stored in the corresponding region. The same applies to the other cells 30, and the control data C for the cell 30 on the lowest potential side (cell C in FIGS. 1 and 3) is also stored in the corresponding region.

In this example, integers 1 to C are stored in the counter set value area 104. In FIG. 3, a variable i containing an integer of 1 to C is set. An initial value of the variable i is set by the control circuit 52, and the variable i is incremented (for example, 1 is added) every time the control circuit 52 transmits the packet data 100. Depending on the initial value, it may be decremented (for example, 1 is subtracted).

As in this example, the counter set value area 104 is not limited to storing one variable (set value), and may store a plurality of set values. In this example, as will be described later, the control circuit 52 increments the set value by one for each transmission of the packet data 100, but inks the two set values one by one for each transmission of the packet data. Etc.

In the converter data area 106, the converter data of the cell 30 identified by the value set by the counter set value can be stored.

The operation of the power conversion device 10 of the embodiment will be described.
FIG. 4 is a schematic diagram for explaining the operation of the power conversion device of the embodiment.
As shown in FIG. 4, the control circuit 52 stores the control data for all the cells 30 in the packet data 100, and sets a counter set value indicating from which cell 30 the converter data is acquired. And store. The control circuit 52 stores all the control data and the counter set values in the packet data 100 and transmits them to the first cell 30 (cell 1 in FIG. 4) via the communication path 61. Each cell 30 acquires control data for itself from the packet data 100 and transfers the packet data 100 to the next cell 30.

A counter set value is set in the packet data 100 in order to acquire the converter data of any cell 30. The target cell 30 determines by itself and writes its own converter data into the packet data 100. The packet data 100a whose data has been updated is transferred to the control circuit 52 when the transfer between the cells 30 is completed.

The control circuit 52 acquires the written converter data. The control circuit 52 transmits the transferred packet data 100a to the cell 30 again in order to acquire the converter data of another cell 30.

By repeating the above operation, the control circuit 52 acquires the converter data of all the cells 30, and generates new control data based on these.

The above-mentioned series of operations will be described with reference to a flowchart.
FIG. 5 is an example of a flowchart for explaining the operation of the power conversion device of the embodiment.
In FIG. 5, the processing in the control device 50, the processing in the first cell 30 (cell 1), the processing in the second cell 30 (cell 2) are shown, and it is shown that the same processing is performed thereafter. ing. The processing in the Cth cell (cell C) is also shown. These cells 1, cell 2, ..., Cell C correspond to, for example, cell 1, cell 2, ..., Cell C in FIGS. 1, 3, and 4. That is, the packet data is transferred in the order of control device 50 → cell 1 → cell 2 → ... → cell C → control device.

Here, it is assumed that cell N (N = 1, 2, ..., C) is called a cell number (denoted as cell No. in FIG. 5) and is assigned to each cell 30 in advance.

As shown in FIG. 5, in the control device 50, the process is started from step S1. In step S1, the control circuit 52 of the control device 50 sets the control data for each cell 30.

In step S2, the control circuit 52 sets the counter set value i to 1, which is the initial value.

In step S3, the control circuit 52 transmits the packet data 100 in which the control data and the counter set value i are stored to the first cell 1.

In cell 1, processing is started from step S11. In step S11, the control circuit 36 of the cell 1 receives the transferred packet data 100.

In step S12, the control circuit 36 in cell 1 acquires and sets its own control data from the received packet data.

In step S13, the control circuit 36 of the cell 1 determines whether or not the counter set value i matches its own cell number. In this example, since the counter set value i is set to "1", the process is shifted to the next step S14.

In step S14, the control circuit 36 of the cell 1 writes its own converter data in the packet data 100.

If the counter set value i is different from its own cell number in step S13, the process is shifted to the next step S15 without performing the process of step S14.

In step S15, the control circuit 36 of the cell 1 transmits the packet data to the next cell 2. In this example, since the converter data in cell 1 has been updated, it is the updated packet data 100a that is transmitted.

In cell 2, in step S21, the control circuit 36 of cell 2 receives the transferred packet data. In this example, what is received is the packet data 100a in which the converter data of the cell 1 is updated.

In step S22, the control circuit 36 of the cell 2 acquires and sets its own control data from the received packet data.

In step S23, the control circuit 36 of the cell 2 determines whether or not the counter set value i matches its own cell number. In this example, since the counter set value i is set to "1", the process is shifted to step S25 without performing the process of step S24.

If the counter set value i matches the own cell number in step S23, the process proceeds to step S24. In step S24, the control circuit 36 of the cell 2 writes its own converter data in the packet data.

In step S25, the control circuit 36 of the cell 2 transmits the packet data to the next cell 3 (not shown).

Hereinafter, although not shown, in each of the cells 3 to (C-1), the control circuit 36 of each cell performs the same processing as the above-mentioned cells 1 and 2. In this example, since the counter set value i is set to "1", the second and subsequent cells directly move to the next cell without writing their own converter data to the transferred packet data 100a. The packet data 100a is transferred.

In cell C, in step SC1, the control circuit 36 of cell 2 receives the transferred packet data. In this example, what is received is the packet data 100a in which the converter data of the cell 1 is updated.

In step SC2, the control circuit 36 in cell C acquires and sets its own control data from the received packet data.

In step SC3, the control circuit 36 of the cell C determines whether or not the counter set value i matches its own cell number. In this example, since the counter set value i is set to "1", the process is shifted to step SC5 without performing the process of step SC4.

If the counter set value i matches the own cell number in step SC3, the process proceeds to step SC4. In step SC4, the control circuit 36 of the cell 2 writes its own converter data in the packet data.

In step SC5, the control circuit 36 in cell C transmits packet data to the control circuit 52 of the control device 50.

The processing moves to the control circuit 52 of the control device 50 again, and in step S4, the control circuit 52 of the control device 50 receives the packet data transferred from the cell C. In this example, the control circuit 52 receives the packet data 100a updated with the converter data of the cell 1.

In step S5, the control circuit 52 of the control device 50 acquires the converter data from the packet data. In this example, the converter data of cell 1 is acquired.

In step S6, the control circuit 52 of the control device 50 confirms whether or not the counter set value i of the received packet data is smaller than the number of cells C. When the counter set value i is smaller than the number of cells C, the process is shifted to the next step S7. When the counter set value i is equal to or greater than the number of cells C, the process ends. After the processing is completed, the control circuit 52 of the control device 50 returns the processing to the first step S1 and repeats the above-described operation.

In step S7, the control circuit 52 of the control device 50 increments the counter set value i to shift the process to step S3. The control circuit 52 of the control device 50 and the control circuit 36 of each cell 30 repeat the processes after step S3 in the same manner as described above.

In this example, the control circuit 52 of the control device 50 receives the packet data 100a updated by the converter data of the cell 1 with the counter set value i set to "1", so that the new counter set value i is set. , Set to "2". The above operation is repeated until the counter set value i is set to "C". By repeating the above operation "C" times, the control circuit 52 of the control device 50 can acquire the converter data of all the cells 30.

In the above, one counter set value is set, and the converter data of all the cells 30 is acquired by repeating the transmission of packet data for the number C of the cells 30, but any counter set value can be set. Of course you can set it.

For example, by setting the counter setting value as [i, i + 2, i + 4, ...], the converter data of the cell 30 having an odd cell number is acquired, and then the converter data of the cell 30 having an even cell number is obtained. Can be obtained. The value to be added after the patrol is not limited to 1, and may be set arbitrarily. For example, when the counter set value is set as [i, i + 1], the converter data of the adjacent cells can be sequentially acquired by adding 2 each time the cycle is performed.

The effect of the power conversion device of the embodiment will be described.
FIG. 6 is a schematic diagram illustrating packet data transmitted in the power conversion device of the comparative example.
As shown in FIG. 6, in the power converter of the comparative example, the packet data 200 transferred in the loop of the daisy chain connection includes the control data area 202 and the converter data area 206. The control data is a control command including data of the gate drive pulse for each cell 30, as in the embodiment.

In the packet data 100 and 200, the required number of words is assigned to each data area. For example, the number of words in each control data is A [words] in both the case of the comparative example and the case of the embodiment, and the number of words can be the same.

In the case of the comparative example, the packet data 200 includes an area for the converter data for each cell, and the number of words of the converter data is B [words]. Therefore, in the case of the comparative example, the length of the packet data 200 is A [word] × C [unit] + B [word] × C [unit].

In the power converter of the comparative example, the converter data is measured each time each cell 30 receives the packet data 200, and the measured converter data is written in the packet data 200. Therefore, the time required to transfer the packet data 200 to the next cell 30 or the control device 50 after receiving the packet data 200 includes the time for acquiring the converter data and the time for writing the converter data to the packet data 200. It becomes the sum of. The time until the packet data 200 goes through the loop of the cells 30 connected in the daisy chain and returns to the control device 50 includes the total time for processing the converter data in each cell 30. Will be.

In the case of the embodiment, the converter data of one cell 30 is included as in the examples of FIGS. 3 to 5, and the packet data 100 includes A [word] × C [unit] + B [word]. ] × 1 [unit] + K [word] area is set. K [word] is an area for the counter set value i, for example, K = 1.

As described above, in the power conversion device 10 of the embodiment, the length of the packet data 100 that circulates the loop of the daisy chain connection can be suppressed.

In the embodiment, the time for processing the converter data can be shortened. In the examples of FIGS. 3 to 5, since one converter data is processed each time the packet data 100 goes around the loop, the processing time of the converter data is set to 1 / C as compared with the case of the comparative example. Can be done. In the embodiment, by reducing the processing time of the converter data, it is possible to shorten the time for the packet data to circulate in the communication path as compared with the case of the comparative example.

Generally, the current, voltage, and the like acquired by each cell 30 are used for feedback, and these fluctuations are sufficiently slower than the setting cycle of the control data including the gate drive pulse. Therefore, the transmission speed of packet data is determined according to the setting cycle of the gate drive pulse for each cell 30.

Further, analog data such as current and voltage acquired by each cell 30 is converted into digital data by an analog-digital converter (A / D converter) and processed by the control circuits 52, 36 and the like. In the A / D converter, the data conversion speed is determined by a predetermined sampling cycle. This sampling cycle is usually sufficiently longer than the control data setting cycle, so even if the control data is set at high speed and the converter data is collected in the control data setting cycle, the collected converter data will be large. It may contain redundant data.

In other words, the period for acquiring the converter data can be determined based on the sampling rate of the A / D converter, and may be shorter than the sampling period of the A / D converter. For example, the period for acquiring converter data is preferably set to be slightly shorter than the minimum value (shortest period) of the sampling period in consideration of variations in the sampling period of the A / D converter. ..

In the power conversion device 10 of the embodiment, the number of words of the packet data 100 can be reduced with respect to the power conversion device of the comparative example, so that the transmission speed of the packet data 100 that circulates in the loop can be reduced as compared with the case of the comparative example. Can be faster. Therefore, since the setting cycle of the control command including the gate drive pulse can be made faster, the power conversion device 10 can be stopped at high speed in the event of an abnormality such as an accident, and the safety can be improved. Becomes possible. Further, the operability of the power conversion device 10 can be improved by increasing the setting cycle of the control command.

By setting the transmission speed of the packet data 100 to be faster, the number of cells 30 per loop can be increased. By increasing the number of cells 30 per loop, the number of optical fiber cables, which are the entire communication paths 60 and 61 of the power conversion device 10, can be reduced, resulting in cost reduction and installation space for the power conversion device 10. Can be reduced.

Further, the control circuit 52 of the control device 50 has a circuit scale corresponding to the number of communication paths 60 and 61. Therefore, by reducing the total number of communication paths 60 and 61, the circuit scale of the control circuit 52 can be reduced, which can contribute to cost reduction and reduction of installation space.

By setting the period for acquiring the converter data to an appropriate value based on the sampling period of the A / D converter in each cell 30, the control device 50 does not acquire redundant converter data. Therefore, the amount of calculation of the control circuit 52 of the control device 50 can be suppressed.

According to the embodiment described above, it is possible to realize a power conversion device having less restrictions on operation even if it has a communication path connected in a daisy chain.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention and its equivalents described in the claims. Moreover, each of the above-described embodiments can be implemented in combination with each other.

1 AC system, 2 transformer, 3 DC system, 10 power converter, 20 power converter, 22 unit arm, 24 transformer, 30 unit converter (cell), 36 control circuit, 50 control device, 52 control circuit, 60,61 communication path, 100,100a packet data

Claims (7)

A power converter that includes multiple converters and
A control device that is daisy-chained to the plurality of converters in a loop and transmits packet data for controlling the plurality of converters to each other.
With
The packet data is
A first area for storing a plurality of control data for controlling the plurality of converters, and
A second area for storing identification data for identifying the plurality of converters, and
Among the plurality of converters, a third area for storing the converter data of the converter having the identification data, and
Including
The number of the identification data stored in the second region is 1 or more, which is smaller than the number of the plurality of converters. The control device is
The plurality of control data are stored in the first area, and the control data is stored.
The identification data is stored in the second area, and the identification data is stored.
The first packet data having the plurality of control data and the identification data is transmitted to the first converter which is one of the plurality of converters.
The first converter is
When the identification data is data that identifies the self, the converter data of the self is written in the third area of the first packet data.
The power according to claim 1, wherein when the identification data is not self-identifying data, the first packet data is transmitted to one of the remaining converters among the plurality of converters without writing the data. Converter. The second converter, which is the other one of the remaining converters, transmits the packet data to the control device.
The control device is
The first packet data is received, the converter data is acquired, and the converter data is acquired.
The power conversion device according to claim 2, wherein a plurality of control data are newly generated based on all the converter data of the plurality of converters. Each of the plurality of converters includes an analog-to-digital converter that measures its own state and converts it into digital data.
The period from when the control device transmits the first packet data to the first converter to when it is received from the second converter is set based on the sampling cycle of the analog-digital converter.
The power conversion device according to claim 3, wherein the period is set shorter than the sampling cycle. The power conversion device according to any one of claims 1 to 4, wherein the number of identification data stored in the second area is 1. The power conversion device according to any one of claims 1 to 4, wherein the number of the identification data stored in the second area is 1/2 of the number of the identification data. The power converter according to any one of claims 1 to 6, wherein the power converter includes a modular multi-level converter.

Images