Power Conversion Equipment

Abstract

A power conversion device according to the present invention comprises a first relay unit, one or more second relay units, and a safety control unit. The first relay unit comprises a first logical processing unit that sends, to an upstream side, a response signal from a first power conversion unit and a response signal from a further downstream side than a host first relay unit. Each of the one or more second relay units includes a second logical processing unit that sends, to a further upstream side than the one second relay unit, a response signal from one second power conversion unit of the one or more second power conversion units and a response signal from a further downstream side than the one second relay unit. The safety control unit is disposed at an upstream side of the first logical processing unit, implements functional safety control of the first power conversion unit and the one or more second power conversion units by sending a control command for functional safety control to the first relay unit, and monitors the state of functional safety control of the first power conversion unit and the state of functional safety control of the one or more second power conversion units.

Description

[Technical field]

[0001] FIELD An embodiment of the present invention relates to a power conversion device. [Background technology]

[0002] Some power conversion devices have a redundant configuration of multiple power conversion units (main circuits), each having a switching element, to increase availability. Functional safety control reduces risks that may occur during system operation. For example, by applying functional safety control to a power conversion device, it is possible to stop the output of power from the power conversion device in response to the risk that has occurred, thereby restricting operation in an unstable state. The configuration and scale of a power conversion device are determined by the user's required specifications, so the power conversion device is required to be able to accommodate various configurations and scales. The more complex the configuration and the larger the scale, the more complex the configuration for functional safety control of the multiple power conversion units becomes, and it may be difficult to collect information indicating the state of functional safety control. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-014321 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a power conversion device capable of collecting, with a simple configuration, information indicating the state of functional safety control of a plurality of redundant power conversion units. [Means for solving the problem]

[0005] In one aspect of the embodiment, a power conversion device includes a plurality of power conversion units divided into banks, and the operating states of the power conversion units are controlled on a bank-by-bank basis. The power conversion device includes a first power conversion unit, a second power conversion unit, a third power conversion unit, a first relay unit, a second relay unit, a third relay unit, and a safety control unit. The first relay unit receives a first Use of the setting signal and a second use setting signal, an A connection port including a terminal for respectively receiving the first use setting signal and a second use setting signal, an A connection port including a terminal for outputting the second use setting signal, an A communication port used for communication with the first power conversion unit, and a safety control unit connection port. The second relay unit includes a B1 connection port connected to the A2 connection port, a B2 connection port including a terminal for outputting the second use setting signal received via the B1 connection port, and a B communication port used for communication with the second power conversion unit. The third relay unit includes a C1 connection port connected to the B2 connection port, a C2 connection port including a terminal capable of outputting the second use setting signal received via the C1 connection port, and a C communication port used for communication with the third power conversion unit. A safety control unit is connected to the safety control unit connection port of the first relay unit and is disposed upstream of the first relay unit. Located in By sending a command signal including a control command for functional safety control to the first relay unit, functional safety control of at least the first power conversion unit, functional safety control of the second power conversion unit, and functional safety control of the third power conversion unit are implemented, and at least a state of functional safety control of the first power conversion unit, a state of functional safety control of the second power conversion unit, and a state of functional safety control of the third power conversion unit are monitored via the first relay unit. The safety control unit, the first relay unit, the second relay unit, and the third relay unit are electrically connected to each other in the connection order of the safety control unit, the first relay unit, the second relay unit, and the third relay unit. In the connection order of the safety control unit, the first relay unit, the second relay unit, and the third relay unit, the safety control unit side is set to the upstream side, and the third relay unit side is set to the downstream side.The first power conversion unit is connected to the A communication port. The second power conversion unit is connected to the B communication port. The third power conversion unit is connected to the C communication port. The first relay unit generates a delayed control command signal by delaying the command signal from the safety control unit by a predetermined time, sends the delayed control command signal from the A2 connection port to the second relay unit, and sends the delayed control command signal from the A communication port to the first power conversion unit when a first condition related to the first use setting signal is satisfied. The second relay unit sends the delayed control command signal from the first relay unit to the third relay unit from the B2 connection port, and sends the delayed control command signal from the first relay unit to the second power conversion unit from the B communication port when a logical value of the second use setting signal and a logical value determined by the connection order of the second relay unit satisfy a second condition. The third relay unit sends the delay control command signal from the second relay unit to the third power conversion unit from the C communication port when the logical value of the second usage setting signal and a logical value determined by the connection order of the third relay unit satisfy a third condition. [Brief description of the drawings]

[0006] [Figure 1A] 1 is a schematic configuration diagram of a power conversion device according to an embodiment; [Figure 1B] FIG. 2 is a schematic configuration diagram of a safety control of the power conversion device according to the embodiment. [Figure 2A] FIG. 2 is a configuration diagram of a power conversion unit according to a first example of the embodiment. [Figure 2B] FIG. 6 is a configuration diagram of a power conversion unit according to a second example of the embodiment. [Figure 3A] FIG. 2 is a configuration diagram of a relay unit group in the power conversion device according to the embodiment. [Figure 3B] FIG. 2 is a configuration diagram of a relay unit group in the power conversion device according to the embodiment. [Figure 4] FIG. 2 is a configuration diagram of a relay unit according to the embodiment. [Diagram 5] FIG. 4 is a diagram for explaining bank selection according to the embodiment. [Figure 6]FIG. 4 is a diagram for explaining bank selection according to the embodiment. [Figure 7] FIG. 4 is a configuration diagram of a selection unit according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, a power conversion device according to an embodiment will be described with reference to the drawings. In the following description, components having the same or similar functions are given the same reference numerals. Duplicate descriptions of those components may be omitted. Electrically connected may simply be referred to as being "connected." The safety control unit monitors the functional safety control state (called the safety control state) of the power conversion unit to be monitored. The side on the safety control unit side is called the upstream side, and the side away from the safety control unit is called the downstream side.

[0008] The power conversion device 1 illustrated in the embodiment has a main circuit that is made redundant so that it can be applied to a system with a relatively high demand for availability. As an example of the redundancy, a case where either or both of standby redundancy and capacity redundancy are applied will be described. Standby redundancy is a method of continuing the operation of the power conversion device 1 by switching the power conversion unit 10 of the standby bank to the active system when the power conversion unit 10 of a specific bank that was the active system in the power conversion device 1 having a configuration including multiple banks fails. Here, a configuration in which one bank is the standby system is illustrated. Capacity redundancy is a method of continuing operation in which a supplyable capacity is provided with a margin with respect to the required capacity of AC power, and even if a failed part is separated, the operation is continued with the remaining configuration to ensure the required capacity.

[0009] (First embodiment) Fig. 1A is a schematic configuration diagram of a power conversion device 1 according to an embodiment. Fig. 1B is a schematic configuration diagram related to safety control of the power conversion device 1 according to an embodiment.

[0010] The power conversion device 1 shown in FIG. 1A includes, for example, power conversion units 11 to 14, a relay unit group 20, a non-safety control unit 30 (non-safety control unit), and a safety control unit 40 (safety control unit).

[0011] Each of the power conversion units 11 to 14 includes, for example, one or more switching elements (not shown) and converts power by switching thereof. The switching elements may be, for example, an insulated gate bipolar transistor (IGBT), an injection enhanced gate transistor (IEGT), or a metal-oxide-semiconductor field-effect transistor (MOSFET). The power conversion unit 11 is an example of a first power conversion unit. The power conversion units 12 to 14 are an example of one or more second power conversion units. Hereinafter, when the power conversion units 11 to 14, which are an example of a plurality of power conversion units, are collectively referred to without distinction, they may be simply referred to as a power conversion unit 10. The power conversion unit 10 functions as an inverter that generates AC power by control and passes a current through the windings of a motor M connected to its output.

[0012] Each power conversion unit 10 is divided into a plurality of banks. For example, the power conversion device 1 controls the operating state of each power conversion unit 10 on a bank-by-bank basis. For example, the power conversion device 1 switches redundancy control on a bank-by-bank basis. The number of banks in the power conversion device 1 can be selected from one to four, for example. For example, the number of banks is determined by the required specifications of the power conversion device 1. In the following description, an example will be given in which the maximum number of banks in the embodiment is four.

[0013] The relay unit group 20 is configured by being divided according to the bank configuration, and includes, for example, relay units 21 to 24. For example, the relay unit 21 is associated with the first bank together with the power conversion unit 11. The relay unit 22 is associated with the second bank together with the power conversion unit 12. The relay unit 23 is associated with the third bank together with the power conversion unit 13. The relay unit 24 is associated with the fourth bank together with the power conversion unit 14.

[0014] The relay unit 21 is an example of a first relay unit. The relay units 22 to 24 correspond to three second relay units and are an example of one or more second relay units. In this manner, the power conversion units 10 are provided downstream of the relay unit group 20. The non-safety control unit 30 and the safety control unit 40 are provided upstream of the relay unit group 20. At least the safety control unit 40 is disposed upstream of the relay unit group 20. The relay unit group 20 relays control of each power conversion unit 10 from the non-safety control unit 30 and the safety control unit 40. The relay unit group 20 relays the state of each power conversion unit 10 to the non-safety control unit 30 and the safety control unit 40.

[0015] The non-safety control unit 30 performs, for example, capacity redundancy control of each power conversion unit 10 and standby redundancy control of each power conversion unit. In the case of capacity redundancy control, the non-safety control unit 30 performs redundant operation by adjusting the amount of power conversion in the power conversion unit 11 and the power conversion units 12 to 14. In the case of standby redundancy control, the non-safety control unit 30 selects a power conversion unit to be activated from the power conversion unit 11 and the power conversion units 12 to 14 by outputting a usage setting signal AD corresponding to the power conversion unit 10 to be operated. The selected power conversion unit 10 thus performs power conversion as an active system, and the non-selected power conversion units 10 become standby systems that do not perform power conversion.

[0016] The safety control unit 40 performs functional safety control of each power conversion unit 10 to reduce risks that may occur during operation of each power conversion unit 10. The safety control unit 40 generates an operation command CMD and controls the output state of each power conversion unit 10 according to the operation command CMD. The safety control unit 40 receives a response signal ANS from each power conversion unit 10 and monitors the operating state of the functional safety control in response to the operation command CMD.

[0017] In the power conversion device 1 configured in this manner, the operating state of each power conversion unit 10 is determined by control from the non-safety control unit 30 and the safety control unit 40. The switching control of the switching elements included in each power conversion unit 10 is determined by control from the non-safety control unit 30. In addition, the output of each power conversion unit 10 may be limited by control from the safety control unit 40. The power conversion device 1 converts a desired amount of power by combining and functioning a plurality of redundant power conversion units 10 to drive the motor M.

[0018] Each part in the power conversion device 1 will be described in more detail below. The power conversion unit 10 of the embodiment will be described with reference to FIGS. 2A and 2B. FIG. 2A is a configuration diagram of a power conversion unit 10A of an embodiment. The power conversion unit 10A is an example of a three-level inverter that generates three-phase AC power. FIG. 2B is a configuration diagram of a power conversion unit 10B of an embodiment. The power conversion unit 10B is an example of a five-level inverter that generates three-phase AC power. The power conversion unit 10A and the power conversion unit 10B are examples of the power conversion unit 10. Below, the power conversion unit 10A and the power conversion unit 10B will be described in order.

[0019] 2A includes a main circuit section 111A, a main circuit control section 112, and a safety stop circuit 113. In addition to the above, for example, an interface section is appropriately provided to electrically insulate the main circuit section 111A from the safety stop circuit 113 and between the safety stop circuit 113 and the relay unit group 20. In the following description, for simplicity, a description of the interface section will be omitted.

[0020] The main circuit unit 111A includes an NPC (Neutral-Point-Crumped) leg including one or more switching elements for each phase of the three-phase AC. The main circuit unit 111A controls switching of one or more switching elements by a gate pulse (gate) described later. When the driving is not limited by a safety stop circuit 113 described later, the main circuit unit 111A receives the gate pulse (gate), and when the driving is limited by the safety stop circuit 113, the supply of the gate pulse (gate) is interrupted. The configuration of the main circuit unit 111A shown in FIG. 2A is an example of a three-level type, and is not limited thereto, and may be another three-level type configuration, for example, a two-level type.

[0021] The main circuit control unit 112 generates a gate pulse (s_gate) for switching one or more switching elements based on the control from the non-safety control unit 30 and the detection results or the estimation results of the control state of various sensors (not shown). The control commands from the non-safety control unit 30 include control commands indicating reference values ​​for, for example, position control, speed control, torque control, etc. The control commands from the non-safety control unit 30 to the main circuit control unit 112 may be supplied directly to the main circuit control unit 112 without going through the relay unit group 20.

[0022] The safety stop circuit 113 is connected to the output of the main circuit control unit 112, and receives a gate pulse (s_gate) from the main circuit control unit 112. When a predetermined condition is satisfied, the safety stop circuit 113 supplies a gate pulse (gate) corresponding to the gate pulse (s_gate) to the main circuit unit 111A, thereby activating the main circuit unit 111A to perform power conversion. Note that when the predetermined condition is not satisfied, the safety stop circuit 113 limits the supply of the gate pulse to the main circuit unit 111A.

[0023] The safety stop circuit 113 is formed to be connected to any one of the relay units 21 to 24 described below. For example, the safety stop circuit 113 of the power conversion unit 11 is controlled by the safety control unit 40 via the relay unit 21. For example, the safety stop circuit 113 receives an operation command CMD via the relay unit 21, and transmits a response signal ANS to the safety control unit 40 in response to the operation command CMD. In Fig. 2A, the operation command CMD and the response signal ANS are denoted as CMD10 and ANS10.

[0024] The above is a description of the power conversion unit 10A shown in Fig. 2A. In contrast, the power conversion unit 10B shown in Fig. 2B includes a main circuit section 111B instead of the main circuit section 111A of the power conversion unit 10A. The following description will focus on the differences.

[0025] The main circuit unit 111B includes two NPC (Neutral-Point-Crumped) type legs each including one or more switching elements for each phase of the three-phase AC. The configuration of the main circuit unit 111B shown in FIG. 2B is an example of a five-level type, and is not limited thereto.

[0026] The output of the first leg in each of the above phases is connected to the windings of the motor M, and the output of the second leg is connected to the neutral point of the AC system. For example, the U phase includes legs U and X, the V phase includes legs V and Y, and the W phase includes legs W and Z. The outputs of legs U, V, and W are connected to the windings of the UVW phases of the motor M, and the outputs of legs X, Y, and Z are connected to the neutral point of the AC system.

[0027] As described above, the power conversion unit 10A and the power conversion unit 10B have different configurations of the main circuits, but the same functional safety control can be applied to them.

[0028] In addition, when the outputs of the power conversion units 10 are connected to one end of a specific winding of the motor M, it is preferable to provide a reactor between the output of each power conversion unit 10 and that one end of the specific winding of the motor M to suppress the transient generation of an excessive current. The above description shows the main connections, and as described above, each connection may include a reactor. The above-mentioned reactors are omitted in Figures 1A, 2A, and 2B. In addition, in the parts that do not require a reactor as described above, the reactor can be omitted as shown in the above figures. When a reactor is provided, a general configuration aimed at the above-mentioned overcurrent protection may be applied.

[0029] When each power conversion unit 10 receives an "output stop" operation command CMD from the safety control unit 40 via the relay unit group 20, the safety stop circuit 113 controls the power conversion unit 10 to stop outputting AC power. This causes each power conversion unit 10 to stop supplying AC power. In response, the supply of AC power to the windings of the motor M stops.

[0030] Next, the relay unit group 20 will be described with reference to FIG. 1A and FIG. 1B. The relay unit 21 includes a first logic processing unit 210 that sends the response signal ANS from the power conversion unit 11 and the response signal ANS from the downstream side of the relay unit 21 to the upstream side. The relay unit 22 includes a second logic processing unit 220 that sends the response signal ANS from the power conversion unit 12 and the response signal ANS from the downstream side of the relay unit 22 to the upstream side. The relay unit 23 includes a second logic processing unit 230 that sends the response signal ANS from the power conversion unit 13 and the response signal ANS from the downstream side of the relay unit 23 to the upstream side. The relay unit 24 includes a second logic processing unit 240 that sends the response signal ANS from the power conversion unit 14 and the response signal ANS from the downstream side of the relay unit 24 to the upstream side. Note that, since no similar relay unit is provided downstream of the relay unit 24, the response signal ANS from the downstream side is not supplied to the second logic processing unit 240.

[0031] In this way, the relay units 21 to 24 are respectively associated with each power conversion unit 10 and are configured to transmit the response signal ANS from each power conversion unit 10 and the response signal ANS from the downstream side of the relay unit to the upstream side.

[0032] The non-safety control unit 30 generates a usage setting signal AD for designating each power conversion unit 10 to be operated in the power conversion apparatus 1, and supplies the usage setting signal AD to the relay units 21 to 24. The usage setting signal AD includes information for designating the power conversion unit 10 to be operated.

[0033] The safety control unit 40 is disposed upstream of the relay unit 21 and is connected to the relay unit 21. In other words, the safety control unit 40 is disposed upstream of the relay units 21 to 24. The safety control unit 40, the relay unit 21, and the relay units 22 to 24 are defined with the safety control unit 40 on the upstream side, and the connection order is defined based on the order of description. The safety control unit 40, the relay unit 21, and the relay units 22 to 24 are electrically connected to each other according to the above-mentioned connection order.

[0034] The safety control unit 40 monitors at least the state of functional safety control of each power conversion unit 10. The safety control unit 40 may send an operation command CMD to each power conversion unit 10 to control each power conversion unit 10.

[0035] For example, the safety control unit 40 includes a safety stop control circuit 41 and a fault diagnosis unit 42. The safety stop control circuit 41 sends an operation command CMD to each power conversion unit 10, and collectively controls the state of the safety stop control in each power conversion unit 10. The operation command CMD output by the safety stop control circuit 41 is, for example, a signal for enabling the functional safety control of each power conversion unit 10 and operating them. When the safety stop control circuit 41 is enabled, for example, it outputs an H-level signal as the operation command CMD.

[0036] Each power conversion unit 10 outputs a response signal ANS10 in response to a safety control signal CMD10 in response to this operation command CMD. The relay units 21 to 24 relay this response signal ANS10 and notify the safety control unit 40. The safety control unit 40 receives a response signal ANS corresponding to this response signal ANS10 as a signal indicating the safety control state of each power conversion unit 10. Note that safety control signals CMD11 to CMD14, which will be described later, are an example of the safety control signals CMD10. Response signals ANS11 to ANS14, which will be described later, are an example of the response signal ANS10.

[0037] When the logic of the operation command CMD sent by the safety control unit 40 corresponds to the logic of the response signal ANS, the fault diagnosis section 42 determines that the functional safety control in the power conversion device 1 is functioning effectively. This will be described in detail later.

[0038] Next, the types of relay units included in the power conversion device 1 will be described. The redundantly configured power conversion device 1 is formed by including two types of relay units regardless of the number of banks. Therefore, in the case of a configuration of three or more banks, the power conversion device 1 uses a plurality of relay units of the same type. The same type of multiple relay units applied to this embodiment are identified by a hardware method to identify which of the multiple relay units of the same type is the one, without a switch operation by a user or a flag setting using software.

[0039] The identification of the relay unit will now be described. In the above-described configuration of three or more banks, a plurality of relay units of the same type configured with common hardware are used. In this case, it is necessary to identify each relay unit. The power conversion device 1 of the present embodiment identifies relay units configured with common hardware based on their mounting positions, for example, as described below. Below, configuration examples for each number of banks will be described.

[0040] For a 2-bank configuration: In the case of a two-bank configuration, it contains one relay unit of type A (called "unit A") and one relay unit of type B (called "unit B"). Note that in this two-bank configuration, there is only one of each relay unit, and no relay units of the same type exist.

[0041] The connection form of this configuration is shown in the following formula (1). The first term is the first bank (called A-bank), and the second term is the second bank (called B-bank). The "+" symbol indicates that the bank is connected. The same applies below.

[0042] (Unit A) + (Unit B) (1)

[0043] The model assignments for A-bank and B-bank that can be read from the relationship in equation (1) above and the characteristics of each connection state are summarized in the following equation (2).

[0044] A-bank: Unit A B-bank: Unit B connected to Unit A (2)

[0045] For a 3-bank configuration: The three-bank configuration includes one unit A and two units B. The connection topology of this configuration is shown in the following equation (3). The third term is the third bank (called C-bank).

[0046] (Unit A) + 1st (Unit B) + 2nd (Unit B) (3)

[0047] The type assignments for each of A-bank to C-bank that can be read from the relationship in equation (3) above and the characteristics of each connection state are summarized in the following equation (4).

[0048] A-bank: Unit A B-bank: A first unit B connected to a unit A and a second unit B C-bank: A second unit B connected to the first unit B (4)

[0049] The four-bank configuration includes one unit A and three units B. The connection topology of this configuration is shown in the following equation (5). The fourth term is the fourth bank (called D-bank).

[0050] (Unit A) + 1st (Unit B) + 2nd (Unit B) + 3rd (Unit B) (5)

[0051] A-bank: Unit A B-bank: A first unit B connected to a unit A and a second unit B C-bank: A second unit B connected to a first unit B and a third unit B D-bank: A third unit B connected to a second unit B (6)

[0052] As described above, even in a configuration including a plurality of relay units of the same type, the banks to which each relay unit is assigned can be identified by identification based on information on the mutual connection relationships between the relay units.

[0053] Next, the configuration of the relay unit group 20 in the power conversion device 1 will be described with reference to Fig. 3A and Fig. 3B. Fig. 3A and Fig. 3B are configuration diagrams of the relay unit group in the power conversion device 1 of the embodiment. Fig. 3A and Fig. 3B show the relay unit group in the power conversion device 1 divided into two. The lower end of Fig. 3A and the upper end of Fig. 3B are connected.

[0054] First, the connection relationships of the relay units in the power conversion device 1 will be summarized. As shown in FIG. 3A, the relay unit 21 includes CNA1-9 as a connector for connecting to the outside.

[0055] The CNA1 includes, for example, a terminal ad. The CNA1 is connected to the non-safety control unit 30. A usage setting signal AD is supplied from the non-safety control unit 30 to the terminal ad of the CNA1.

[0056] CNA2 has terminals bh and k, and a power supply terminal pair (not shown). Terminals bd of CNA2 are connected to terminals bd of CNA1 in the relay unit 21. Terminals ef of CNA2 are connected to inputs of the composite gate circuit 214 in the relay unit 21. Terminal g of CNA2 is connected to an input terminal of CNA3 in the relay unit 21 through a first delay circuit (DLY). Terminal h of CNA2 is connected to an input terminal of CNA4 in the relay unit 21 through a second delay circuit (DLY). Terminal k of CNA1 is pulled up to a positive power supply voltage in the relay unit 21 and set to H level. A predetermined DC voltage is supplied between the terminals of the power supply terminal pair (not shown) from within the relay unit 21. CNA2 is connected to CNB1 of the relay unit 22.

[0057] The output terminal of CNA3 and the output terminal of CNA4 are each connected to the output of the composite gate circuit 214. CNA3 and CNA4 are each connected to the safety control unit 40.

[0058] The CNAs 5-8 are each connected to the power conversion unit 11. The CNAs 5 and 7 send a safety control signal CMD11 to the power conversion unit 11. The CNAs 5 and 7 include, for example, an electrical-optical converter. The CNAs 6 and 8 receive a response signal ANS11 to the safety control signal CMD11 from the power conversion unit 11. The CNAs 5 and 7 include, for example, an optical-electrical converter. The CNAs 5-8 may be connectors for transmitting optical signals.

[0059] The relay unit 22 includes CNBs 1-2 and 5-8 as connectors for connecting to the outside. CNB1 has a terminal bh, a terminal kl, and a power supply terminal pair (not shown). CNB1 is connected to CNA2 of the relay unit 21. A terminal bk of CNB1 is connected to a terminal bk of CNA2. A use setting signal BD is supplied to a terminal bd of CNB1 from the non-safety control unit 30 via the relay unit 21. A terminal ef of CNB1 is connected to an output of a composite gate circuit 224 of the relay unit 22. A terminal gh of CNB1 is connected to a terminal gh of CNB2 in the relay unit 22. A terminal k of CNB1 is connected to an input of a selector 221 of the relay unit 22. A terminal l of CNB1 is connected to a terminal l of CNA2 of the relay unit 21, and a positive power supply voltage is supplied to the terminal l of CNB1 in the relay unit 22, and the terminal l is set to an H level. The circuit (225) that supplies a positive power supply voltage to terminal l of CNB1 is an example of a first voltage setting circuit (referred to as the first voltage setting circuit 225) that outputs a first signal of H level from the relay unit 22 to the relay unit 21 on the upstream side thereof.

[0060] CNB2 has a terminal bh, a terminal kl, and a power supply terminal pair (not shown). A terminal bd of CNB2 is connected to a terminal bd of CNB1 in the relay unit 22. A terminal ef of CNB2 is connected to an input of a composite gate circuit 224 of the relay unit 22. A terminal gh of CNB2 is connected to a terminal gh of CNB1 in the relay unit 21. A terminal k of CNB2 is connected to a positive power supply in the relay unit 22 and set to H level. CNB2 is connected to CNC1 of the relay unit 23. When the terminal l of CNB2 is open, the terminal l of CNB2 becomes L level due to the presence of a pull-down resistor in the relay unit 22. This terminal l of CNB2 is set to H level due to the connection of the relay unit 23. The circuit (226) that supplies an L-level voltage to terminal k of CNB2 is an example of a second voltage setting circuit (referred to as the second voltage setting circuit 226) that outputs an L-level second signal from relay unit 22 to relay unit 23 downstream of it.

[0061] CNB5-8 are each connected to the power conversion unit 12. CNB5 and 7 include connectors for sending a safety control signal CMD12 to the power conversion unit 12. CNB6 and 8 include connectors for receiving a response signal ANS12 to the safety control signal CMD12 from the power conversion unit 12. CNB5-8 may be connectors for optical signals.

[0062] The relay unit 23 includes CNCs 1-2 and 5-8 as connectors for connecting to the outside.

[0063] The relay unit 24 includes connectors CND1-2 and CND5-8 for connecting to the outside.

[0064] The relay units 23 and 24 have the same configuration as the relay unit 22, and the connection relationships of the various parts in each relay unit are the same as those of the relay unit 22. For example, the safety control signal in the relay unit 23 and the response signal thereto are the safety control signal CMD13 and the response signal ANS13. The safety control signal in the relay unit 24 and the response signal thereto are the safety control signal CMD14 and the response signal ANS14.

[0065] The connection relationship between the relay unit 23 and the relay unit 24 and the other relay units is as follows. CNC1 of the relay unit 23 is connected to CNB2 of the relay unit 22. CND1 of the relay unit 24 is connected to CNC2 of the relay unit 22. CND2 of the relay unit 24 may be unconnected. Terminal 1 of CND2 of the relay unit 24 is open and is not connected to anything outside the relay unit 24, so it is set to L level by a pull-down resistor in the relay unit 24.

[0066] The connection relationship between the relay unit 23, the relay unit 24, and the power conversion units therefor is as follows: The CNCs 5-8 of the relay unit 23 are connected to the power conversion unit 13, respectively. The CNCs 5-8 of the relay unit 24 are connected to the power conversion unit 14, respectively.

[0067] Next, the internal configuration of each relay unit will be described.

[0068] Relay unit 21 applied to A-bank includes, for example, input gate circuit 212, output gate circuit 213, and compositing gate circuit 214. Input gate circuit 212, output gate circuit 213, and compositing gate circuit 214 may be part of first logic processing unit 210 described above.

[0069] The input gate circuit 212 restricts acquisition of the response signal ANS of the power conversion unit 11 based on the usage setting signal A. For example, when the usage setting signal A is at L level, the input gate circuit 212 restricts acquisition of the response signal ANS of the power conversion unit 11, and when the usage setting signal A is at H level, the input gate circuit 212 acquires and outputs the response signal ANS of the power conversion unit 11.

[0070] The output gate circuit 213 limits the output of the command signal CMD from the safety control unit 40 to the power conversion unit 11 based on the use setting signal A. For example, when the use setting signal A is at L level, the output gate circuit 213 limits the output of the command signal CMD from the safety control unit 40 to the power conversion unit 11, and when the use setting signal A is at H level, the output gate circuit 213 outputs the command signal CMD from the safety control unit 40 to the power conversion unit 11. For example, the command signal CMD may include stop control signals ST01_CMD and ST02_CMD. The stop control signals ST01_CMD and ST02_CMD are examples of redundant command signals CMD. The stop control signals ST01_CMD and ST02_CMD are sent to the power conversion unit 12 from the CNB5 and CNB7, respectively, as safety control signals.

[0071] The synthesis gate circuit 214 synthesizes a response signal ANS11a corresponding to the response signal ANS11 of the power conversion unit 11 obtained without being restricted by the input gate circuit 212, and a response signal ANS11b from downstream of the power conversion unit 11, and outputs the resulting signal.

[0072] For example, the logic of the response signal ANS11, the response signal ANS11a, and the response signal ANS11b is such that an H level indicates an output permitted state, and an L level indicates an output stopped state. When the safety control unit 40 outputs an operation command CMD indicating an output stop, each power conversion unit 10 that has received the operation command CMD stops output in response to the operation command CMD, and outputs a response signal (e.g., the response signal ANS11) indicating an output stopped state. In this state, there is no H level response signal. However, if there is an H level response signal in this state, there is a possibility that some abnormality has occurred. The composite gate circuit 214 is configured as a positive logic OR circuit, and can transfer the presence of an H level response signal to the upstream side. The mechanism of this response signal transfer is the same for the relay unit 22 to the relay unit 24 described later.

[0073] Next, the configuration of the relay unit 22 of the embodiment will be described with reference to Fig. 4. Fig. 4 is a configuration diagram of the relay unit 22 of the embodiment.

[0074] Relay unit 22 applied to B-bank includes selector 221, input gate circuit 222, output gate circuit 223, and composite gate circuit 224. In addition to the above, relay unit 22 further includes a first voltage setting circuit 225 for outputting a first signal from relay unit 22 to its upstream side, and a second voltage setting circuit 226 for outputting a second signal from relay unit 22 to its downstream side. For example, selector 221, input gate circuit 222, output gate circuit 223, and composite gate circuit 224 may be part of second logic processing unit 220.

[0075] The selector 221 selects one of the usage setting signals BD (the first usage setting signal to the third usage setting signal) based on the logical value of the W signal (the second signal) and the logical value of the Z signal (the first signal) to generate a usage setting signal SOUT.

[0076] For example, the selector 221 may be configured as follows. The selector 221 includes selectors 221a and 221b, and an OR gate circuit 221c.

[0077] A use setting signal B of the B-bank and a use setting signal C of the C-bank are respectively supplied to a first input (H) and a second input (L) of the selector 221a. A second signal (W) output by the upper relay unit 21 is supplied to the control terminal. When the second signal (W) is at H level (high level), the selector 221a outputs the use setting signal B of the B-bank, and when the second signal (W) is at L level (low level), the selector 221a outputs the use setting signal C of the C-bank. The selector 221a is configured to select either the use setting signal B (first use setting signal) or the use setting signal C (second use setting signal) based on the logical value of the second signal (W) as described above.

[0078] The output signal of the selector 221a and the D-bank use setting signal D are respectively supplied to a first input (H) and a second input (L) of the selector 221b. The output of the OR gate circuit 221c is connected to the control terminal of the selector 221b.

[0079] A first input of the OR gate circuit 221c is supplied with the second signal (W) output by the upper relay unit 21. A second input of the OR gate circuit 221c is supplied with a signal (Zs) of either the logical value of the first signal (Z) output by the downstream relay unit 23 or the logical value of the third signal generated in the relay unit 22. In other words, the control terminal of the selector 221b is configured to be supplied with the logical sum of the signal (Zs) of either the logical value of the first signal (Z) output by the downstream relay unit 23 or the logical value of the third signal generated in the relay unit 22, and the second signal (W) output by the upper relay unit 21.

[0080] Since the relay unit 22 is connected to the relay unit 23 on the downstream side, the control terminal of the selector 221b is supplied with an H level corresponding to the logical value of the first signal (Z) output by the relay unit 23, which corresponds to the former one described above. When the first signal (Z) is at an H level, the selector 221b outputs the output signal of the selector 221a, and when the second signal is at an L level, it outputs a use setting signal D of the D-bank. This selector 221b selects either the selection result by the selector 221a or the use setting signal D (third use setting signal) based on the result of the logical OR operation based on either the logical value of the first signal (Z) or the logical value of the third signal and the logical value of the second signal (W) as described above.

[0081] In this way, the selector 221 is configured to select one of the use setting signals B to D based on the logical value of the first signal (Z) and the logical value of the second signal (W).

[0082] The input gate circuit 222 restricts acquisition of the response signal ANS12a corresponding to the response signal ANS12 of the power conversion unit 12 based on the use setting signal SOUT indicating the result of the selection by the selector 221. For example, when the use setting signal SOUT is at L level, the input gate circuit 222 restricts acquisition of the response signal ANS12a of the power conversion unit 12, and when the use setting signal SOUT is at H level, the input gate circuit 222 acquires and outputs the response signal ANS12a of the power conversion unit 12.

[0083] The output gate circuit 223 restricts relay of the command signal CMD from the safety control unit 40 to the power conversion unit 12 based on the use setting signal SOUT indicating the result of the selection by the selector 221. For example, when the use setting signal SOUT is at an L level, the output gate circuit 223 restricts the output of the command signal CMD from the safety control unit 40 to the power conversion unit 12, and when the use setting signal SOUT is at an H level, the output gate circuit 223 outputs the command signal CMD from the safety control unit 40 to the power conversion unit 12. The above command signal CMD may include stop control signals ST01_CMD and ST02_CMD.

[0084] The combination gate circuit 224 combines the response signal ANS12a of the power conversion unit 12 (its own power conversion unit related to its own second relay unit) acquired without being restricted by the input gate circuit 222 with the response signal ANS12b from the downstream side of the power conversion unit 12, and outputs the resulting signal.

[0085] As shown in FIG. 3B, the relay unit 23 applied to the C-bank includes a selector 231, an input gate circuit 232, an output gate circuit 233, and a combining gate circuit 234.

[0086] The relay unit 24 applied to the D-bank includes a selector 241 , an input gate circuit 242 , an output gate circuit 243 , and a synthesis gate circuit 244 .

[0087] The relay units 23 and 24 are the same units as the relay unit 22 described above. The relay units 23 and 24 are arranged in a different order from the relay unit 22 described above, and therefore the bank selection operations of the selectors 231 and 241 are different from those of the selector 221.

[0088] Bank selection by relay units 22 to 24 will be described with reference to Fig. 5 and Fig. 6. Fig. 5 and Fig. 6 are diagrams for explaining bank selection in the embodiment. The truth table shown in Fig. 5 shows the relationship between the setting signals of relay units 22 to 24 and the output signals of selectors 221, 231, and 241.

[0089] The setting signals "W", "X", "Y", and "Z" in the table, and the output signal "SOUT" correspond to the signals shown in Figure 4. The state of the signal is indicated by two values, H level and L level.

[0090] "X" and "Y" are fixed to H level and L level, respectively. These are signals that contribute to the bank selection decision in the relay unit of the adjacent bank, but do not contribute to the bank selection decision in itself (relay unit 22). Therefore, within itself (relay unit 22), the above "W" and "Z" are used as input signals to selectors 221, 231, and 241. This truth table shows the conditions corresponding to B-bank to D-bank from the top.

[0091] The output signal "SOUT" is an output signal of the selectors 221, 231, and 241. When there is a match between the B-bank and the D-bank, the H level is selected.

[0092] From the truth table shown in FIG. 5, the ranges used for the input signals of the selectors 221, 231, and 241 are extracted and reorganized in FIG.

[0093] For example, the logical value of the signal (Y) output by relay unit 21 (first relay unit), in other words, the logical value of the signal W of the B-bank related to the second signal, is a first logical value (for example, "1" corresponding to the H level). On the other hand, the logical value of the signal (Y) output by relay units 22 to 24 (second relay unit), in other words, the logical value of the signal W of the B-bank related to the second signal, is a second logical value (for example, "0" corresponding to the L level).

[0094] For example, the relay unit 24 arranged in the D-bank located most downstream generates a third signal having a second logic value of "0" in the relay unit 24. The relay unit 24 uses the second logic value of "0" as the logical value of the third signal.

[0095] In contrast, relay units 22 and 23, excluding relay unit 24 arranged on the most downstream side among relay units 22 to 24 (second relay units), are different from relay unit 24 described above. Relay unit 23 uses a first signal (Z) with a logical value of "1" output by relay unit 24 on the downstream side. Relay unit 22 uses a first signal (Z) with a logical value of "1" output by relay unit 23 on the downstream side. The logical value of the first signal (Z) and the logical value of the third signal generated in relay units 22 to 24 are complementary to each other.

[0096] As can be seen from the truth table shown in FIG. 6, the relay unit assigned to each bank can identify the position of its own relay unit (the position of its own bank) by receiving a signal from the relay unit of the adjacent bank adjacent to its own bank.

[0097] As described above, in the following predetermined cases, the relay units 22 to 24 send the response signal ANS of the power conversion unit related to the relay unit to the upstream side of the relay unit in response to the use setting signal of each bank. Regardless of the predetermined case, the relay units 22 to 24 send the response signal ANS from the downstream side of the power conversion unit to the upstream side of the power conversion unit. Note that the above predetermined case may be, for example, a case in which the logical value of the first signal (Z) output by the downstream relay unit (second relay unit) and the logical value of the third signal generated in the relay unit, and the logical value of the second signal output by the upstream side are each a predetermined value determined by the connection order of each relay unit.

[0098] Furthermore, in response to a usage setting signal BD for each bank from B-bank to D-bank, the relay units 22 to 24 acquire a command signal CMD from the upstream side of the own relay unit as a signal for the own power conversion unit related to the above relay unit among the power conversion units 12 to 14. The relay units 22 to 24 each supply this signal to the own power conversion unit corresponding to the own relay unit.

[0099] Focusing on the use setting signal AD of each bank, the relay unit 21 receives the use setting signal AD of each bank from the non-safety control unit 30, which is an external device of the relay unit 21, and relays the use setting signal BD to its downstream side. The relay units 22 to 24 receive the use setting signal BD of each bank from the upstream side and relay it to the downstream side. It is preferable that the relay unit 21 is configured to use only the use setting signal A of each bank internally. In contrast, the use setting signal A is not supplied to the relay units 22 to 24.

[0100] The command signal CMD from the safety control unit 40 is made redundant. The relay units 21 to 24 (first relay unit and second relay unit) relay the command signal CMD for the redundant functional safety control to the downstream side, respectively.

[0101] When a predetermined condition determined by the connection order is satisfied, the relay units 21 to 24 relay the redundant command signal CMD to one of the corresponding power conversion units 11 to 14. For example, the predetermined condition being satisfied means that the corresponding bank is designated as the bank to be used by the usage setting signal.

[0102] For example, the usage setting signal includes usage setting signal B (first usage setting signal) to usage setting signal D (third usage setting signal) for selecting the relay units of the first to third banks from the upstream side for relay units 22 to 24, respectively.

[0103] FIG. 7 is a configuration diagram of a selection unit according to the embodiment. The selector 221 can be expanded into a combinational circuit of two-input gate circuits. With this number of gate stages and circuit scale, it can be accommodated in a single semiconductor device such as a PLD. The circuit shown in FIG. 7 is an example, and is not limited to this.

[0104] Next, the functional safety control of the embodiment will be described. A command signal CMD for functional safety control is supplied to the power conversion unit of the activated bank. For example, the non-safety control unit 30 outputs a usage setting signal AD for each bank to be activated, independent of the functional safety control. The relay units (21 to 24) of each bank identify the activated state by the usage setting signal AD corresponding to that bank.

[0105] When the safety control unit 40 supplies a command signal CMD to the relay unit 21 for functional safety control, the relay units 21 to 24 relay this command signal CMD in sequence. The relay units 21 to 24 of the activated bank relay the command signal CMD to the respective power conversion units 11 to 14. The power conversion unit 10 to which the command signal CMD is supplied outputs power. The power conversion unit 10 to which the command signal CMD is supplied returns a response signal ANS in response to this to the relay unit.

[0106] Each relay unit collects response signals ANS from the power conversion units of each activated bank, logically combines them, and relays them to the upstream side. If the response signals ANS collected and relayed by each relay unit are at L level, it is determined that the functional safety control is functioning normally. If the response signal ANS is at H level, it may be determined that a state in which the functional safety control is not functioning normally has occurred.

[0107] For example, when any of the relay units collects and relays a response signal ANS of H level, the final response signal ANS supplied to the safety control unit 40 becomes H level. If the collected response signal ANS is H level when the safety control unit 40 has notified the output stop by the command signal CMD, the safety control unit 40 identifies that the power conversion units to which the command signal CMD has been supplied include a power conversion unit in which the functional safety control is not functioning normally. The safety control unit 40, upon detecting such a state, switches the range of operation in cooperation with the non-safety control unit 30 to make the collected response signal ANS become L level. This identifies that a fault may have occurred in the power conversion unit that was removed from the operation targets.

[0108] Although a state in which functional safety control is not functioning properly is not an appropriate state, the possibility of this being the cause of a serious fault is low. Therefore, by following the procedure described above, the power conversion unit in which functional safety control is not functioning properly is switched from the active system to the standby system and becomes the subject of inspection and maintenance. By taking such measures, the system can be restored to the required operating state without shutting down the entire system.

[0109] The relay units 21 to 24 of the banks that are not selected to be operated do not relay the command signal CMD to the corresponding power conversion units. The power conversion units to which the command signal CMD is not supplied are controlled not to output power.

[0110] The above description of the operation has been centered on functional safety, but it is also possible to carry out switching between the active system and the standby system for the purpose of avoiding a fault, etc., independently of this.

[0111] According to at least one embodiment described above, the power conversion device includes a first relay unit, one or more second relay units, and a safety control unit. In a first bank associated with the first power conversion unit, the first relay unit sends a response signal ANS from the first power conversion unit and a response signal ANS from the downstream side of the first relay unit to the upstream side. In one or more second banks associated with one or more second power conversion units, the one or more second relay units send a response signal ANS from one second power conversion unit among the one or more second power conversion units and a response signal ANS from the downstream side of the one second relay unit to the upstream side of the one second relay unit. The safety control unit is disposed on the upstream side of the first relay unit, and performs functional safety control of the first power conversion unit and the one or more second power conversion units by sending a control command for functional safety control to the first relay unit, and monitors a state of functional safety control of the first power conversion unit and a state of functional safety control of the one or more second power conversion units. This makes it possible to collect information indicating the state of functional safety control of multiple redundant power conversion units with a simple configuration.

[0112] The non-safety control unit 30 and the safety control unit 40 may be realized, at least in part, by a software function unit that functions when a processor such as a CPU executes a program, or may be realized entirely by a hardware function unit such as an LSI.

[0113] Although some 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 embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention.

[0114] For example, instead of the three-level configuration (FIG. 2A) illustrated above, a five-level configuration (FIG. 2B) may be applied. [Explanation of symbols]

[0115] 1...power conversion device, 10, 11, 12, 13, 14...power conversion unit, 20...relay unit group, 21, 22, 23, 24...relay unit, 30...non-safety control unit (non-safety control unit), 40...safety control unit 40 (safety control unit), 221, 231, 241...selector, 212, 222, 232, 242...input gate circuit, 213, 223, 233, 243...output gate circuit, 214, 224, 234, 244 OR gate circuit (composite gate circuit)

Claims

1. A power conversion device in which a plurality of power conversion units are divided into banks, and an operating state of the power conversion units is controlled on a bank-by-bank basis, A first power conversion unit; A second power conversion unit; A third power conversion unit; and a first relay unit including an A1 connection port including a terminal for receiving a first use setting signal and a second use setting signal from an external device, an A2 connection port including a terminal for outputting the second use setting signal, an A communication port used for communication with the first power conversion unit, and a safety control unit connection port; a second relay unit including a B1 connection port connected to the A2 connection port, a B2 connection port including a terminal for outputting the second use setting signal received via the B1 connection port, and a B communication port used for communication with the second power conversion unit; a third relay unit including a C1 connection port connected to the B2 connection port, a C2 connection port including a terminal capable of outputting the second use setting signal received via the C1 connection port, and a C communication port used for communication with the third power conversion unit; a safety control unit that is connected to the safety control unit connection port of the first relay unit, is disposed upstream of the first relay unit, and performs functional safety control of at least the first power conversion unit, functional safety control of the second power conversion unit, and functional safety control of the third power conversion unit by sending a command signal including a control command for functional safety control to the first relay unit, and monitors at least a state of functional safety control of the first power conversion unit, a state of functional safety control of the second power conversion unit, and a state of functional safety control of the third power conversion unit via the first relay unit; Equipped with the safety control unit, the first relay unit, the second relay unit, and the third relay unit are electrically connected to each other in a connection order of the safety control unit, the first relay unit, the second relay unit, and the third relay unit, In a connection order of the safety control unit, the first relay unit, the second relay unit, and the third relay unit, the safety control unit side is an upstream side, and the third relay unit side is a downstream side, the first power conversion unit is connected to the A communication port; the second power conversion unit is connected to the B communication port; the third power conversion unit is connected to the C communication port; The first relay unit is generating a delayed control command signal by delaying the command signal from the safety control unit by a predetermined time, sending the delayed control command signal from the A2 connection port to the second relay unit, and sending the delayed control command signal from the A communication port to the first power conversion unit when a first condition related to the first use setting signal is satisfied; The second relay unit is sending the delay control command signal from the first relay unit from the B2 connection port to the third relay unit, and sending the delay control command signal from the first relay unit from the B communication port to the second power conversion unit when a logical value of the second use setting signal and a logical value determined by the connection order of the second relay unit satisfy a second condition; The third relay unit is sending the delay control command signal from the second relay unit to the third power conversion unit from the C communication port when a logical value of the second use setting signal and a logical value determined by the connection order of the third relay unit satisfy a third condition; Power conversion equipment.

2. The second relay unit and the third relay unit are configured as relay units having a common configuration, The relay unit includes: Each relay unit includes a first voltage setting circuit that outputs a first signal from its own relay unit to its upstream side, and a second voltage setting circuit that outputs a second signal from its own relay unit to its downstream side, The relay unit identifies the applied bank based on a logical value of a first signal output by a relay unit downstream of the relay unit itself and a logical value of a second signal output by a relay unit upstream of the relay unit itself. The power conversion device according to claim 1 .

3. The second relay unit, In response to the second use setting signal, the delay control command signal from the first relay unit is acquired as a signal for the second power conversion unit associated with the second relay unit, and the acquired signal is supplied to each of the second power conversion units. The power conversion device according to claim 2 .

4. The relay unit generates a third signal indicating whether or not another relay unit is connected to the downstream side of the relay unit depending on whether or not the relay unit receives the first signal from the downstream side, The logic value of the first signal that the relay unit receives from the downstream side and the logic value of the third signal that is generated in the relay unit because the relay unit does not receive the first signal from the downstream side are complementary to each other. The power conversion device according to claim 2 .

5. the first relay unit outputs a second signal having a first logic value H to the downstream side; the second relay unit outputs a second signal having a second logic value L to the downstream side; The second relay unit and the third relay unit are Receive a second signal from the upstream side, and identify whether the upstream relay unit is the first relay unit or the second relay unit from the logical value of the second signal. Identify the connection order of the own relay unit using the result of the identification. The second relay unit and the third relay unit are outputting a first signal having a first logic value H to each upstream side; using a logical value of a terminal that receives a first signal supplied from the downstream side of the own relay unit, to identify whether or not there is a connection of another relay unit on the downstream side of the own relay unit; The power conversion device according to claim 2 .

6. The first relay unit is receiving a response signal indicating a state of functional safety control of the first power conversion unit, a response signal indicating a state of functional safety control of the second power conversion unit and a response signal indicating a state of functional safety control of the third power conversion unit transmitted from the second relay unit; sending a response signal indicating at least a functional safety control state of the first power conversion unit, a functional safety control state of the second power conversion unit, and a functional safety control state of the third power conversion unit to the safety control unit; The second relay unit is receiving a response signal indicating a state of functional safety control of the second power conversion unit and a response signal indicating a state of functional safety control of the third power conversion unit transmitted from the third relay unit, Sending a response signal indicating at least a state of functional safety control of the second power conversion unit and a state of functional safety control of the third power conversion unit to the first relay unit; The third relay unit is receiving a response signal indicating a state of functional safety control of the third power conversion unit; A response signal indicating a state of functional safety control of at least the third power conversion unit is sent to the second relay unit. The power conversion device according to claim 1 .

7. The command signal and the delay control command signal from the safety control unit are made redundant, The first relay unit and the second relay unit respectively relay the redundant delay control command signal to the downstream side. The power conversion device according to claim 1 .

8. the first relay unit outputs the redundant delayed control command signal to the first power conversion unit when the first condition is satisfied; the second relay unit outputs the redundant delayed control command signal to the second power conversion unit when the second condition is satisfied. The power converter according to claim 7.

9. A power conversion device in which a plurality of power conversion units are divided into banks, and an operating state of the power conversion units is controlled on a bank-by-bank basis, A first power conversion unit; A second power conversion unit; A third power conversion unit; and A fourth power conversion unit; and a first relay unit including an A1 connection port including a terminal for receiving a first use setting signal and a second use setting signal from an external device, an A2 connection port including a terminal for outputting the second use setting signal, an A communication port used for communication with the first power conversion unit, and a safety control unit connection port; a second relay unit including a B1 connection port connected to the A2 connection port, a B2 connection port including a terminal for outputting the second use setting signal received via the B1 connection port, and a B communication port used for communication with the second power conversion unit; a third relay unit including a C1 connection port connected to the B2 connection port, a C2 connection port including a terminal capable of outputting the second use setting signal received via the C1 connection port, and a C communication port used for communication with the third power conversion unit; a fourth relay unit including a D1 connection port connected to the C2 connection port, a D2 connection port including a terminal capable of outputting the second use setting signal received via the D1 connection port, and a D communication port used for communication with the fourth power conversion unit; a safety control unit that is connected to the safety control unit connection port of the first relay unit, is disposed upstream of the first relay unit, and performs functional safety control of at least the first power conversion unit, functional safety control of the second power conversion unit, functional safety control of the third power conversion unit, and functional safety control of the fourth power conversion unit by sending a command signal including a control command for functional safety control to the first relay unit, and monitors at least a state of the functional safety control of the first power conversion unit, a state of the functional safety control of the second power conversion unit, a state of the functional safety control of the third power conversion unit, and a state of the functional safety control of the fourth power conversion unit via the first relay unit; Equipped with the safety control unit, the first relay unit, the second relay unit, the third relay unit, and the fourth relay unit are electrically connected to each other in a connection order of the safety control unit, the first relay unit, the second relay unit, the third relay unit, and the fourth relay unit, In a connection order of the safety control unit, the first relay unit, the second relay unit, the third relay unit, and the fourth relay unit, the safety control unit side is an upstream side, and the fourth relay unit side is a downstream side, the first power conversion unit is connected to the A communication port; the second power conversion unit is connected to the B communication port; the third power conversion unit is connected to the C communication port; the fourth power conversion unit is connected to the D communication port; The first relay unit is generating a delayed control command signal by delaying the command signal from the safety control unit by a predetermined time, sending the delayed control command signal from the A2 connection port to the second relay unit, and sending the delayed control command signal from the A communication port to the first power conversion unit when a first condition related to the first use setting signal is satisfied; The second relay unit is sending the delay control command signal from the first relay unit from the B2 connection port to the third relay unit, and sending the delay control command signal from the first relay unit from the B communication port to the second power conversion unit when a logical value of the second use setting signal and a logical value determined by the connection order of the second relay unit satisfy a second condition; The third relay unit is sending the delay control command signal from the second relay unit from the C2 connection port to the fourth relay unit, and sending the delay control command signal from the second relay unit from the C communication port to the third power conversion unit when a logical value of the second use setting signal and a logical value determined by the connection order of the third relay unit satisfy a third condition; The fourth relay unit is sending the delay control command signal from the third relay unit to the fourth power conversion unit from the D communication port when a logical value of the second use setting signal and a logical value determined by the connection order of the fourth relay unit satisfy a fourth condition; Power conversion equipment.

10. the first relay unit outputs a second signal having a first logic value H to the downstream side; the second relay unit outputs a second signal having a second logic value L to the downstream side; The second relay unit and the third relay unit are Receive a second signal from the upstream side of the own relay unit, and identify whether the relay unit on the upstream side of the own relay unit is the first relay unit or the second relay unit from the logical value of the second signal, and identify the connection order of the own relay unit using the result of the identification, The second relay unit and the third relay unit are outputting a first signal having a first logic value H to each upstream side; Using a logical value of a terminal that receives a first signal supplied from the downstream side of the repeater unit, identify whether or not there is a connection of another repeater unit on the downstream side of the repeater unit, The second relay unit is a selector configured to be able to select any one of a first use setting signal, a second use setting signal, and a third use setting signal included in the second use setting signal, the selector selecting the first use setting signal based on a logical value of the first signal received by the second relay unit from the third relay unit and a logical value of the second signal received by the second relay unit from the first relay unit; an input gate circuit that limits acquisition of a response signal from the second power conversion unit according to the connection order; an output gate circuit that limits an output of the delay control command signal to the second power conversion unit according to the connection order; a synthesis gate circuit that outputs a signal obtained by synthesizing a response signal of the second power conversion unit related to the second relay unit, which is acquired without being restricted by the input gate circuit, and a response signal from a downstream side of the second relay unit; The power converter according to claim 9 .

11. The second relay unit, the third relay unit, and the fourth relay unit, an input gate circuit that acquires a response signal from a power conversion unit corresponding to the relay unit in the connection order based on the second use setting signal and the connection order, and restricts acquisition of a response signal from a power conversion unit different from the connection order; an output gate circuit that limits an output of the delay control command signal to the power conversion unit corresponding to the connection order based on the second use setting signal and the connection order; A synthesis gate circuit that outputs a signal obtained by synthesizing a response signal of the power conversion unit related to the relay unit and a response signal from a power conversion unit relayed by a relay unit downstream of the relay unit; The power conversion device according to claim 9 ,

12. a non-safety control unit that adjusts the power conversion amounts in the first power conversion unit, the second power conversion unit, and the third power conversion unit to perform capacity redundancy control of each of the power conversion units; The power conversion device according to claim 1 .

13. a non-safety control unit that outputs the first use setting signal and the second use setting signal for selecting a power conversion unit to be activated from among the first power conversion unit, the second power conversion unit, and the third power conversion unit; Equipped with The non-safety control unit is The external device performs standby redundancy control of the power conversion unit. The power conversion device according to claim 1 .

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