Power conversion device

Abstract

The power conversion device includes a first relay unit, one or more second relay units, and a safety control unit. The first relay unit includes a first logic processing unit that transmits a response signal from the first power conversion unit and a response signal from a downstream side of the first relay unit to an upstream side. The one or more second relay units each include a second logic processing unit that transmits a response signal from one of the one or more second power conversion units and a response signal from a downstream side of the second relay unit to an upstream side of the second relay unit. The safety control unit is located upstream of the first logic processing unit and implements functional safety control of the first power conversion unit and the one or more second power conversion units by transmitting control instructions for functional safety control to the first relay unit, and monitors the status of the functional safety control of the first power conversion unit and the one or more second power conversion units.

Description

Technical Field

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

[0002] Among power conversion devices, there are power conversion devices that improve availability by making multiple power conversion units (main circuits) each having a switching element redundant. Functional safety control is used to reduce the risks generated during the operation of the system. For example, by applying functional safety control to the power conversion device, the power output from the power conversion device is stopped according to the generated risk, and operation in an unstable state can be restricted. The structure and scale of the power conversion device are determined according to the user's required specifications, so as a power conversion device, it is required to be able to cope with various structures and scales. The more complex its structure becomes and the larger its scale becomes, the more complex the structure of the multiple power conversion units for functional safety control becomes, and sometimes it is difficult to collect information representing the status of functional safety control.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-014321 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] An object of the present invention is to provide a power conversion device capable of collecting information indicating the status of functional safety control of a plurality of redundant power conversion units with a simple configuration.

[0008] Means for solving problems

[0009] In one embodiment, a power conversion device comprises a plurality of power conversion units divided into a plurality of groups, and the operating state of the power conversion units is controlled on a group basis. The power conversion device includes a first relay unit, one or more second relay units, and a safety control unit. The first relay unit transmits a response signal from the first power conversion unit and a response signal from a downstream side of the first relay unit to an upstream side in a first group corresponding to the first power conversion unit. The one or more second relay units transmit a response signal from one of the one or more second power conversion units and a response signal from a downstream side of the one second relay unit to an upstream side of the one second relay unit in one or more second groups corresponding to the one or more second power conversion units. The above-mentioned safety control unit is arranged on the upstream side of the above-mentioned first relay unit, and implements the functional safety control of the above-mentioned first power conversion unit and the functional safety control of the above-mentioned one or more second power conversion units by transmitting an instruction signal containing a control instruction for functional safety control to the above-mentioned first relay unit, and monitors the status of the functional safety control of the above-mentioned first power conversion unit and the status of the functional safety control of the above-mentioned one or more second power conversion units. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A It is a schematic configuration diagram of a power conversion device according to an embodiment.

[0011] Figure 1B This is a schematic diagram of the safety control structure of the power conversion device according to the embodiment.

[0012] Figure 2A It is a configuration diagram of a power conversion unit according to a first example of the embodiment.

[0013] Figure 2B It is a configuration diagram of a power conversion unit according to a second example of the embodiment.

[0014] Figure 3A It is a diagram showing the configuration of a relay unit group in the power conversion device according to the embodiment.

[0015] Figure 3B It is a diagram showing the configuration of a relay unit group in the power conversion device according to the embodiment.

[0016] Figure 4 This is a diagram showing the configuration of a relay unit according to the embodiment.

[0017] Figure 5 This is a diagram for explaining group selection in the embodiment.

[0018] Figure 6 This is a diagram for explaining group selection in the embodiment.

[0019] Figure 7 This is a diagram showing the configuration of a selection unit in an embodiment. DETAILED DESCRIPTION

[0020] Hereinafter, the power conversion device of the embodiment will be described with reference to the accompanying drawings. In addition, in the following description, the same symbols are marked for components having the same or similar functions. However, repeated descriptions of these components may be omitted. In addition, electrical connection is sometimes simply referred to as "connection". In addition, the safety control unit monitors the state of functional safety control of the power conversion unit that is the monitored object (referred to as the safety control state). The side of the safety control unit is referred to as the upstream side, and the side away from the safety control unit is referred to as the downstream side.

[0021] In addition, the power conversion device 1 illustrated in the embodiment is a device in which the main circuit is redundant so that it can be applied to a system with relatively high requirements for availability. As an example of its redundancy, an example of applying either or both of standby redundancy and capacity redundancy is described. Standby redundancy refers to a method in which, in a power conversion device 1 configured to include a plurality of banks, when a power conversion unit 10 of a specific bank that becomes an active system fails, the power conversion unit 10 of the bank that becomes a standby system is switched to the active system, and the operation of the power conversion device 1 is continued. Here, a configuration in which one bank becomes a standby system is illustrated. Capacity redundancy refers to a method in which a supply capacity is configured with a margin relative to the required capacity of AC power, and even if the failed portion is cut off, the operation can be continued by the remaining configuration to ensure continued operation of the required capacity.

[0022] (First embodiment)

[0023] Figure 1A It is a schematic configuration diagram of the power conversion device 1 according to the embodiment. Figure 1B It is a schematic configuration diagram of the safety control of the power conversion device 1 according to the embodiment.

[0024] Figure 1A The illustrated power conversion device 1 includes, for example, power conversion units 11 to 14 , a relay unit group 20 , a non-safety control unit 30 (non-safety control section), and a safety control unit 40 (safety control section).

[0025] The power conversion units 11 to 14 each include, for example, one or more switching elements (not shown), through which power is converted. The type of switching element may be IGBT (Insulated Gate Bipolar Transistor), IEGT (Injection Enhanced Gate Transistor), MOSFET (metal-oxide-semiconductor field-effect transistor), etc. The power conversion unit 11 is an example of a first power conversion unit. The power conversion units 12 to 14 are examples of one or more second power conversion units. Hereinafter, when an example of a plurality of power conversion units, i.e., the power conversion units 11 to 14, is generally represented without distinguishing them, it is sometimes referred to as the power conversion unit 10. The power conversion unit 10 functions as an inverter that generates AC power through control, and current flows to the winding of the motor M connected to its output.

[0026] Each power conversion unit 10 is organized into multiple groups. For example, the power conversion device 1 controls the operating state of each power conversion unit 10 on a group-by-group basis. For example, the power conversion device switches redundant control on a group-by-group basis. The number of groups in the power conversion device 1 can be selected from, for example, 1 to 4. For example, the number of groups is determined based on the required specifications of the power conversion device 1. The following description uses the example of a maximum group configuration of 4 in the embodiment.

[0027] The relay unit group 20 is divided into groups and includes, for example, relay units 21 to 24. For example, relay unit 21 and power conversion unit 11 are associated with the first group. Relay unit 22 and power conversion unit 12 are associated with the second group. Relay unit 23 and power conversion unit 13 are associated with the third group. Relay unit 24 and power conversion unit 14 are associated with the fourth group.

[0028] The relay unit 21 is an example of a first relay unit. Furthermore, relay units 22 to 24 correspond to three second relay units and are examples of one or more second relay units. Thus, power conversion units 10 are provided on the downstream side of the relay unit group 20. A non-safety control unit 30 and a safety control unit 40 are provided on the upstream side of the relay unit group 20. At least the safety control unit 40 is positioned 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 status of each power conversion unit 10 to the non-safety control unit 30 and the safety control unit 40.

[0029] The non-safety control unit 30, for example, implements capacity redundancy control for each power conversion unit 10 and standby redundancy control for each power conversion unit. Under capacity redundancy control, the non-safety control unit 30 implements redundant operation by adjusting the power conversion amounts of the power conversion unit 11 and the power conversion units 12 to 14. Under standby redundancy control, the non-safety control unit 30 outputs a usage setting signal AD corresponding to the operating power conversion unit 10, thereby selecting an active power conversion unit from the power conversion units 11 and 12 to 14. The selected power conversion unit 10 performs power conversion as the active system, while the unselected power conversion units 10 become standby systems, not performing power conversion.

[0030] The safety control unit 40 implements functional safety control of each power conversion unit 10 to reduce risks arising from the 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 based on the operation command CMD. The safety control unit 40 receives a response signal ANS from each power conversion unit 10 and monitors the operational status of the functional safety control in response to the operation command CMD.

[0031] In the power conversion device 1 thus configured, 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. Furthermore, 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 to drive the motor M by operating a combination of multiple redundant power conversion units 10.

[0032] Hereinafter, each component in the power conversion device 1 will be described in more detail in sequence.

[0033] Reference Figure 2A and Figure 2B The power conversion unit 10 according to the embodiment will be described.

[0034] Figure 2A 10A is a block diagram of a power conversion unit according to the embodiment. The power conversion unit 10A is an example of a three-level inverter that generates three-phase AC power. Figure 2B This is a diagram illustrating the configuration of a power conversion unit 10B according to 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. The power conversion unit 10A and the power conversion unit 10B are described below in order.

[0035] Figure 2A The power conversion unit 10A shown includes a main circuit unit 111A, a main circuit control unit 112, and a safety stop circuit 113. In addition to the above, an interface unit is appropriately provided, for example, to electrically insulate the main circuit unit 111A and the safety stop circuit 113, and the safety stop circuit 113 and the relay unit group 20. In the following description, the description of these interfaces is omitted for simplicity.

[0036] The main circuit unit 111A includes one NPC (Neutral-Point-Crumped) bridge leg (1) for each phase of the three-phase AC power supply. Each leg includes one or more switching elements. Main circuit unit 111A controls the switching of one or more switching elements using gate pulses (described later). Unless the safety stop circuit 113 (described later) limits its operation, the main circuit unit 111A receives gate pulses. When the safety stop circuit 113 limits its operation, the main circuit unit 111A interrupts the gate pulse supply. Figure 2A The illustrated configuration of the main circuit unit 111A is an example of a three-level configuration, but the present invention is not limited thereto and may have a configuration other than a three-level configuration, such as a two-level configuration.

[0037] The main circuit control unit 112 generates gate pulses (s_gate) for switching one or more switching elements based on control from the non-safety control unit 30, as well as detection results from various sensors (not shown), or estimated control state results. Control commands from the non-safety control unit 30 include, for example, control commands indicating reference values ​​for position control, speed control, torque control, and the like. Alternatively, the non-safety control unit 30 can directly supply control commands to the main circuit control unit 112 without passing through the relay unit group 20.

[0038] Safety stop circuit 113 is connected to the output of main circuit control unit 112 and receives a gate pulse (s_gate) from main circuit control unit 112. When specified conditions are met, safety stop circuit 113 supplies a gate pulse (gate) corresponding to the gate pulse (s_gate) to main circuit unit 111A, thereby activating main circuit unit 111A and performing power conversion. Furthermore, when specified conditions are not met, safety stop circuit 113 restricts the supply of the gate pulse to main circuit unit 111A.

[0039] The safety stop circuit 113 is connected to any one of the relay units 21 to 24 described later. For example, the safety stop circuit 113 of the power conversion unit 11 receives control from the safety control unit 40 via the relay unit 21. For example, the safety stop circuit 113 receives the operation command CMD via the relay unit 21, and responds to it by sending a response signal ANS to the safety control unit 40. Figure 2A In FIG, the operation command CMD and the response signal ANS are recorded as CMD10 and ANS10.

[0040] The above is with Figure 2A In contrast, Figure 2B The power conversion unit 10B shown includes a main circuit unit 111B instead of the main circuit unit 111A of the power conversion unit 10A. The following description will focus on the differences.

[0041] The main circuit unit 111B includes two NPC (Neutral-Point-Crumped) type bridge arms for each phase of the three-phase AC, and each bridge arm includes one or more switching elements. Figure 2B The configuration of the main circuit portion 111B shown is an example of a five-level system, but is not limited thereto.

[0042] The output of the first bridge arm in each of the above phases is connected to the windings of motor M, and the output of the second bridge arm is connected to the neutral point of the AC system. For example, the U phase includes bridge arms U and X, the V phase includes bridge arms V and Y, and the W phase includes bridge arms W and Z. The outputs of bridge arms U, V, and W are connected to the windings of phases U, V, and W of motor M, while the outputs of bridge arms X, Y, and Z are connected to the neutral point of the AC system, respectively.

[0043] As described above, the power conversion unit 10A and the power conversion unit 10B have different main circuit configurations, but can be used for similar functional safety control.

[0044] 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 the end of the specific winding of the motor M to suppress the transient generation of excessive current. The above description shows the main connections, and as mentioned above, a reactor may also be included in each connection. Figure 1A 、 Figure 2A 、 Figure 2B The description of the reactor is omitted in the above description. In addition, in the part where the reactor is not required as described above, the reactor can be omitted as shown in the above drawings. When the reactor is provided, the general structure for the purpose of the above overcurrent protection can also be applied.

[0045] When each power conversion unit 10 receives the "output stop" operation command CMD from the safety control unit 40 via the relay unit group 20, it is controlled by the safety stop circuit 113 to stop outputting AC power. This causes each power conversion unit 10 to stop supplying AC power. Consequently, the supply of AC power to the windings of the motor M is also stopped.

[0046] Next, refer to Figure 1A and Figure 1B The relay unit group 20 will be described.

[0047] Relay unit 21 includes a first logic processing unit 210 that transmits the response signal ANS from power conversion unit 11 and the response signal ANS from the downstream side of relay unit 21 upstream. Relay unit 22 includes a second logic processing unit 220 that transmits the response signal ANS from power conversion unit 12 and the response signal ANS from the downstream side of relay unit 22 upstream. Relay unit 23 includes a second logic processing unit 230 that transmits the response signal ANS from power conversion unit 13 and the response signal ANS from the downstream side of relay unit 23 upstream. Relay unit 24 includes a second logic processing unit 240 that transmits the response signal ANS from power conversion unit 14 and the response signal ANS from the downstream side of relay unit 24 upstream. Since no similar relay unit is provided downstream of relay unit 24, second logic processing unit 240 is not supplied with the response signal ANS from the downstream side.

[0048] In this manner, the relay units 21 to 24 are configured to correspond to the respective power conversion units 10 and transmit the response signal ANS from the respective power conversion units 10 and the response signal ANS from the downstream side of the relay unit to the upstream side.

[0049] The non-safety control unit 30 generates a use setting signal AD for designating each power conversion unit 10 operating in the power conversion device 1, and supplies the signal to the relay units 21 to 24. The use setting signal AD includes information for instructing the power conversion unit 10 to operate.

[0050] The safety control unit 40 is located upstream of the relay unit 21 and is connected to the relay unit 21. In other words, the safety control unit 40 is located 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 connected in the order described, with the safety control unit 40 being located upstream. The safety control unit 40, the relay unit 21, and the relay units 22 to 24 are electrically connected to each other in this order.

[0051] 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 also control each power conversion unit 10 by transmitting an operation command CMD to each power conversion unit 10.

[0052] 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 transmits an operation command CMD to each power conversion unit 10, centrally controlling the safety stop control state of 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 causing it to operate. When enabled, the safety stop control circuit 41 outputs, for example, an H-level signal as the operation command CMD.

[0053] Each power conversion unit 10 outputs a response signal ANS10 in response to the safety control signal CMD10 for the operation command CMD. Relay units 21 to 24 relay this response signal ANS10 and notify the safety control unit 40. The safety control unit 40 receives the response signal ANS corresponding to this response signal ANS10 as a signal indicating the safety control state of each power conversion unit 10. Safety control signals CMD11 to CMD14, described later, are examples of safety control signals CMD10. Response signals ANS11 to ANS14, described later, are examples of response signals ANS10.

[0054] 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 unit 42 determines that the functional safety control of the power conversion device 1 is effectively functioning. The details will be described later.

[0055] Next, types of relay units included in the power conversion device 1 will be described.

[0056] The redundantly configured power conversion device 1 includes two types of relay units, regardless of the number of groups. Therefore, in a configuration with three or more groups, multiple relay units of the same type are used in the power conversion device 1. In this embodiment, multiple relay units of the same type are used so that identification of which of the multiple relay units is used is not based on user switch operation or software flag setting, but rather is performed using hardware.

[0057] Identification of the relay unit will be described.

[0058] As described above, in a configuration with three or more groups, multiple relay units of the same type, constructed with common hardware, are used. In this case, it is necessary to identify each relay unit. The power conversion device 1 of this embodiment, for example, identifies relay units constructed with common hardware based on their installation positions, as described below. Configuration examples for each number of groups are described below.

[0059] Two groups of situations:

[0060] In the case of a two-group configuration, there is one relay unit of type A (referred to as "unit A") and one relay unit of type B (referred to as "unit B"). In addition, in the case of the two-group configuration, there is only one relay unit for each type, and no relay units of the same type exist.

[0061] The connection of this structure is schematically represented by the following formula (1). The first term is the first group (called A-bank), and the second term is the second group (called B-bank). The "+" symbol indicates connection. The same applies to the following.

[0062] (Unit A) + (Unit B) (1)

[0063] For each of A-bank and B-bank read from the relationship of the above formula (1), the type assignment and the characteristics of each connection state are organized into the following formula (2).

[0064] A-bank: Unit A

[0065] B-bank: Unit B connected to unit A (2)

[0066] The three groups consist of:

[0067] In the case of a three-bank structure, it includes one unit A and two units B. The connection mode of this structure is schematically represented by the following formula (3): The third term is the third bank (referred to as C-bank).

[0068] (Unit A) + First (Unit B) + Second (Unit B) (3)

[0069] For each of A-bank to C-bank read from the relationship of the above formula (3), the type assignment and the characteristics of each connection state are organized into the following formula (4).

[0070] A-bank: Unit A

[0071] B-bank: The first unit B connected to unit A and the second unit B

[0072] C-bank: Second unit B connected to first unit B (4)

[0073] In the case of a four-bank configuration, there are one unit A and three units B. The connection method of this configuration is schematically represented by the following equation (5): The fourth term is the fourth bank (referred to as D-bank).

[0074] (Unit A) + first (Unit B) + second (Unit B) + third (Unit B) (5)

[0075] A-bank: Unit A

[0076] B-bank: The first unit B connected to unit A and the second unit B

[0077] C-bank: Second unit B connected to first unit B and third unit B

[0078] D-bank: The third unit B connected to the second unit B (6)

[0079] As described above, even in a configuration including a plurality of relay units of the same type, the group to which each relay unit is assigned can be identified by identification based on information on the mutual connection relationship between the relay units.

[0080] Next, refer to Figure 3A and Figure 3B The configuration of the relay unit group 20 in the power conversion device 1 will be described. Figure 3A and Figure 3B : is a diagram showing the configuration of a relay unit group in the power conversion device 1 according to the embodiment. Figure 3A and Figure 3B 1 shows the relay unit group in the power conversion device 1 as divided into two. Figure 3A The lower end of Figure 3B The upper end of the connection.

[0081] First, the connection relationship between the relay units in the power conversion device 1 is sorted out.

[0082] like Figure 3A As shown, the relay unit 21 includes CNA1 - 9 as connectors for connecting to the outside.

[0083] CNA1 includes, for example, terminals ad. CNA1 is connected to the non-safety control unit 30. The use setting signal AD is supplied from the non-safety control unit 30 to the terminals ad of CNA1.

[0084] CNA2 includes terminals bh, k, and a power supply terminal pair (not shown). Terminal bd of CNA2 is connected to terminals bd of CNA1 within relay unit 21. Terminal ef of CNA2 is connected to the inputs of combined gate circuit 214 of relay unit 21. Terminal g of CNA2 is connected to the input terminal of CNA3 within relay unit 21 via a first delay circuit (DLY). Terminal h of CNA2 is connected to the input terminal of CNA4 within relay unit 21 via a second delay circuit (DLY). Terminal k of CNA1 is pulled up by the positive power supply voltage within relay unit 21 and set to an H level. A predetermined DC voltage is supplied between the terminals of the power supply terminal pair (not shown) from within relay unit 21. CNA2 is connected to CNB1 of relay unit 22.

[0085] The output terminal of CNA3 and the output terminal of CNA4 are connected to the output of the synthesis gate circuit 214. CNA3 and CNA4 are connected to the safety control unit 40, respectively.

[0086] CNAs 5-8 are respectively connected to power conversion unit 11. CNAs 5 and 7 transmit safety control signals CMD11 to power conversion unit 11. CNAs 5 and 7 include, for example, electro-optical converters. CNAs 6 and 8 receive response signals ANS11 to safety control signals CMD11 from power conversion unit 11. CNAs 5 and 7 include, for example, photoelectric converters. CNAs 5-8 may also be connectors for transmitting optical signals.

[0087] The relay unit 22 includes CNBs 1 - 2 and 5 - 8 as connectors for connecting to the outside.

[0088] CNB1 includes a terminal bh, a terminal kl, and a pair of power supply terminals (not shown). CNB1 is connected to CNA2 of the relay unit 21. Terminal bk of CNB1 is connected to terminal bk of CNA2. A use setting signal BD is supplied from the non-safety control unit 30 via the relay unit 21 to terminal bd of CNB1. Terminal ef of CNB1 is connected to the output of the synthesis gate circuit 224 of the relay unit 22. Terminal gh of CNB1 is connected to terminal gh of CNB2 within the relay unit 22. Terminal k of CNB1 is connected to the input of the selector 221 of the relay unit 22. Terminal l of CNB1 is connected to terminal l of CNA2 of the relay unit 21, and a positive power supply voltage is supplied to the relay unit 22, which is set to an H level. The circuit (225) that supplies the positive power supply voltage to terminal l of CNB1 is an example of a first voltage setting circuit (referred to as a first voltage setting circuit 225) that outputs an H-level first signal from the relay unit 22 to the upstream relay unit 21.

[0089] CNB2 includes terminals bh, kl, and a pair of power supply terminals (not shown). Terminal bd of CNB2 is connected to terminals bd of CNB1 within relay unit 22. Terminal ef of CNB2 is connected to inputs of combined gate circuit 224 of relay unit 22. Terminal gh of CNB2 is connected to terminal gh of CNB1 within relay unit 21. Terminal k of CNB2 is connected to the positive power supply within relay unit 22 and is set to an H level. CNB2 is connected to CNC1 of relay unit 23. When terminal l of CNB2 is open, the pull-down resistor within relay unit 22 causes terminal l of CNB2 to be at an L level. Terminal l of CNB2 is connected to relay unit 23 and is therefore set to an H level. The circuit (226) that supplies an L-level voltage to the terminal k of the 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 the relay unit 22 to the relay unit 23 on the downstream side thereof.

[0090] CNBs 5-8 are respectively connected to power conversion unit 12. CNBs 5 and 7 include connectors for sending safety control signal CMD12 to power conversion unit 12. CNBs 6 and 8 include connectors for receiving response signal ANS12 to safety control signal CMD12 from power conversion unit 12. CNBs 5-8 may also be connectors for optical signals.

[0091] The relay unit 23 includes CNC1 - 2 and 5 - 8 as connectors for connection to the outside.

[0092] The relay unit 24 includes CNDs 1 - 2 and 5 - 8 as connectors for connecting to the outside.

[0093] Relay units 23 and 24 have the same configuration as relay unit 22, and the connections between the components within each relay unit are the same as those in relay unit 22. For example, the safety control signal in relay unit 23 and the response signal thereto are safety control signal CMD13 and response signal ANS13, respectively. The safety control signal in relay unit 24 and the response signal thereto are safety control signal CMD14 and response signal ANS14, respectively.

[0094] The connection relationship between relay unit 23 and relay unit 24 and the other relay units is as follows. CNC1 of relay unit 23 is connected to CNB2 of relay unit 22. CND1 of relay unit 24 is connected to CNC2 of relay unit 22. Alternatively, CND2 of relay unit 24 may be unconnected. Terminal 1 of CND2 of relay unit 24 is open and not connected to the outside of relay unit 24. Therefore, the pull-down resistor within relay unit 24 keeps the terminal at an L level.

[0095] The connection relationship between the relay unit 23 and the relay unit 24 and the power conversion unit is as follows: The CNC5-8 of the relay unit 23 is connected to the power conversion unit 13. The CND5-8 of the relay unit 24 is connected to the power conversion unit 14.

[0096] Next, the internal structure of each relay unit will be described.

[0097] The relay unit 21 used in the A-bank includes, for example, an input gate circuit 212, an output gate circuit 213, and a synthesizing gate circuit 214. The input gate circuit 212, the output gate circuit 213, and the synthesizing gate circuit 214 are part of the first logic processing unit 210 described above.

[0098] The input gate circuit 212 limits the acquisition of the response signal ANS of the power conversion unit 11 based on the use setting signal A. For example, when the use setting signal A is at an L level, the input gate circuit 212 limits the acquisition of the response signal ANS of the power conversion unit 11, and when it is at an H level, the input gate circuit 212 acquires and outputs the response signal ANS of the power conversion unit 11.

[0099] 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 usage setting signal A. For example, when the usage setting signal A is at an 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. When the usage setting signal A is at an 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 also 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 as safety control signals from CNB5 and CNB7 to the power conversion unit 12, respectively.

[0100] The synthesizing gate circuit 214 synthesizes the 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 the response signal ANS11b from the downstream side of the power conversion unit 11, and outputs the resulting signal.

[0101] For example, the logic of the response signal ANS11, the response signal ANS11a, and the response signal ANS11b is that the H level indicates the output allowed state, and the L level indicates the output stopped state. When the safety control unit 40 outputs the operation instruction CMD indicating that the output is stopped, each power conversion unit 10 that receives the operation instruction CMD stops the output according to the operation instruction CMD, and outputs a response signal (such as response signal ANS11) indicating the output stopped state. If it is in this state, there is no H-level response signal. However, if there is an H-level response signal in this state, some kind of abnormality may have occurred. The synthetic gate circuit 214 is composed of a positive logic OR circuit, which can transmit the existence of the H-level response signal to the upstream side. The mechanism of transmitting the response signal is the same for the relay unit 22 to the relay unit 24 described later.

[0102] Next, refer to Figure 4 The configuration of the relay unit 22 according to the embodiment will be described. Figure 4 It is a diagram showing the configuration of the relay unit 22 according to the embodiment.

[0103] The relay unit 22 used in the B-bank includes a selector 221, an input gate circuit 222, an output gate circuit 223, and a synthesizing gate circuit 224. In addition to the above, the relay unit 22 also includes a first voltage setting circuit 225 for outputting a first signal from the relay unit 22 to its upstream side, and a second voltage setting circuit 226 for outputting a second signal from the relay unit 22 to its downstream side. For example, the selector 221, the input gate circuit 222, the output gate circuit 223, and the synthesizing gate circuit 224 may also be part of the second logic processing unit 220.

[0104] The selector 221 selects any one of the use setting signals BD (first to third use setting signals) based on the logic value of the W signal (second signal) and the logic value of the Z signal (first signal), and generates the use setting signal SOUT.

[0105] For example, the selector 221 may be configured as follows.

[0106] The selector 221 includes line selectors 221 a and 221 b , and an OR gate circuit 221 c .

[0107] The first input (H) and second input (L) of the line selector 221a are supplied with the usage setting signal B for B-bank (group B) and the usage setting signal C for C-bank (group C), respectively. The control terminal of the line selector 221a is supplied with the second signal (W) output by the upper relay unit 21. When the second signal (W) is at an H level (high level), the line selector 221a outputs the usage setting signal B for B-bank, and when the second signal (W) is at an L level (low level), the line selector 221a outputs the usage setting signal C for C-bank. As described above, the line selector 221a is configured to select either the usage setting signal B (first usage setting signal) or the usage setting signal C (second usage setting signal) based on the logic value of the second signal (W).

[0108] The first input (H) and the second input (L) of the line selector 221b are respectively supplied with the output signal of the line selector 221a and the D-bank use setting signal D. The output of the OR circuit 221c is connected to its control terminal.

[0109] The first input of the OR gate circuit 221c is supplied with the second signal (W) output by the upper relay unit 21. The second input of the OR gate circuit 221c is supplied with a signal (Zs) having 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 by the relay unit 22. Specifically, the control terminal of the line selector 221b is supplied with a signal (Zs) having 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 by the relay unit 22, and the logical sum of the signal (Zs) having 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 by the relay unit 22, and the second signal (W) output by the upper relay unit 21.

[0110] Furthermore, since the relay unit 22 is connected to the relay unit 23 on the downstream side, an H level corresponding to the logical value of the first signal (Z) outputted from the relay unit 23, which corresponds to the former, is supplied to the control terminal of the line selector 221b. The line selector 221b outputs the output signal of the line selector 221a when the first signal (Z) is at an H level, and outputs the D-bank usage setting signal D when the second signal is at an L level. As described above, the line selector 221b selects either the selection result of the line selector 221a or the usage setting signal D (third usage setting signal) based on the result of the logical sum calculation 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).

[0111] In this manner, the selector 221 is formed to select any one of the use setting signal B to the use setting signal D based on the logic value of the first signal (Z) and the logic value of the second signal (W).

[0112] The input gate circuit 222 restricts the 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 selection result of the selector 221. For example, when the use setting signal SOUT is at an L level, the input gate circuit 222 restricts the acquisition of the response signal ANS12a of the power conversion unit 12, and when it is at an H level, the input gate circuit 222 acquires and outputs the response signal ANS12a of the power conversion unit 12.

[0113] The output gate circuit 223 restricts the 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 selection result of 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 command signal CMD may also include the stop control signals ST01_CMD and ST02_CMD.

[0114] The synthetic gate circuit 224 synthesizes the response signal ANS12a of the power conversion unit 12 (the self-power conversion unit from the second relay unit) obtained without being restricted by the input gate circuit 222 and the response signal ANS12b from the downstream side of the power conversion unit 12, and outputs the resulting signal.

[0115] like Figure 3B As shown, the relay unit 23 used in the C-bank includes a selector 231 , an input gate circuit 232 , an output gate circuit 233 , and a combining gate circuit 234 .

[0116] The relay unit 24 used in the D-bank includes a selector 241 , an input gate circuit 242 , an output gate circuit 243 , and a synthesizing gate circuit 244 .

[0117] Relay units 23 and 24 are the same as relay unit 22. Relay units 23 and 24 are arranged in a different order from relay unit 22, so the operations of selectors 231 and 241 related to group selection differ from those of selector 221.

[0118] Reference Figure 5 and Figure 6 The group selection performed by the relay units 22 to 24 will be described. Figure 5 and Figure 6 This is a diagram for explaining group selection in the embodiment. Figure 5The truth table shown shows the relationship between the setting signals of the relay units 22 to 24 and the output signals of the selectors 221 , 231 , and 241 .

[0119] The table shows the setting signal "W", "X", "Y", "Z", and the output signal "SOUT" and Figure 4 The signal state is represented by two values: H level and L level.

[0120] "X" and "Y" are fixed at H and L levels, respectively. These signals contribute to the group selection decision in the adjacent relay unit, but do not contribute to the group selection decision in the relay unit itself (relay unit 22). Therefore, in the relay unit itself (relay unit 22), the above-mentioned "W" and "Z" are used as input signals for selectors 221, 231, and 241. In this truth table, the conditions corresponding to B-bank through D-bank are shown in order from the top.

[0121] The output signal "SOUT" is an output signal of the selectors 221, 231, and 241. When the signals are consistent with those of the B-bank and D-bank, the H level is selected.

[0122] From the above Figure 5 The range of input signals for selectors 221, 231, and 241 is extracted from the truth table shown and rearranged as Figure 6 .

[0123] For example, the logic value of the signal (Y) output by relay unit 21 (first relay unit), in other words, the logic value of signal W of the B-bank associated with the second signal, is a first logic value (e.g., "1" corresponding to an H level). In contrast, the logic value of the signal (Y) output by relay units 22 to 24 (second relay units), in other words, the logic value of signal W of the B-bank associated with the second signal, is a second logic value (e.g., "0" corresponding to an L level).

[0124] For example, the relay cell 24 disposed in the most downstream D-bank generates a third signal having a second logic value of "0" in the relay cell 24. The relay cell 24 uses the second logic value "0" as the logic value of the third signal.

[0125] In contrast, relay units 22 and 23, excluding relay unit 24 located on the most downstream side of relay units 22 to 24 (the second relay unit), differ from relay unit 24 described above. Relay unit 23 utilizes the first signal (Z) with a logical value of "1" output by relay unit 24 on the downstream side. Relay unit 22 utilizes the first signal (Z) with a logical value of "1" output by relay unit 23 on the downstream side. Furthermore, the logical value of the first signal (Z) and the logical value of the third signal generated by relay units 22 to 24 are mutually complementary.

[0126] As according to Figure 6 As can be seen from the truth table shown, the relay unit assigned to each group can receive signals from the relay unit of the adjacent group and can recognize the position of its own relay unit (the position of its own group).

[0127] As described above, the relay units 22 to 24 transmit the response signal ANS of the self-power conversion unit related to the self-relay unit to the upstream side of the self-relay unit according to the usage setting signal of each group under the following prescribed conditions. The relay units 22 to 24 transmit the response signal ANS from the downstream side of the self-power conversion unit to the upstream side of the self-power conversion unit regardless of the prescribed conditions. In addition, the prescribed conditions may be, for example, the following: the logic value of the first signal (Z) output by the relay unit (second relay unit) on the downstream side and any one of the logic values ​​of the third signal generated in the self-relay unit, and the logic value of the second signal output from the upstream side are respectively prescribed values ​​determined according to the connection order of each relay unit.

[0128] Furthermore, the relay units 22 to 24 receive the command signal CMD from the upstream side of the relay unit based on the usage setting signal BD for each of the B-bank (group B) to D-bank (group D) groups, as a signal for the power conversion unit associated with the relay unit among the power conversion units 12 to 14. The relay units 22 to 24 supply this signal to the power conversion unit associated with the relay unit.

[0129] Focusing on the usage setting signals AD for each group, relay unit 21 receives the usage setting signals AD for each group from a non-safety control unit 30, an external device to relay unit 21, and relays the usage setting signals BD downstream. Relay units 22 through 24 receive the usage setting signals BD for each group from the upstream side and relay them downstream. Alternatively, relay unit 21 may be configured to utilize only the usage setting signals A for each group. In contrast, relay units 22 through 24 are not supplied with the usage setting signals A.

[0130] The command signal CMD from the safety control unit 40 is made redundant.

[0131] The relay units 21 to 24 (the first relay unit and the second relay unit) relay the redundant command signal CMD for functional safety control to the downstream side.

[0132] Relay units 21 to 24 relay redundant command signals CMD to any of the corresponding power conversion units 11 to 14 when a predetermined condition determined by the connection order is satisfied. For example, satisfying the predetermined condition means that the corresponding group is designated as the used group by the use setting signal.

[0133] For example, the use setting signal includes use setting signal B (first use setting signal) to use setting signal D (third use setting signal) for selecting first to third groups of relay units from the upstream side thereof for the relay units 22 to 24 , respectively.

[0134] Figure 7 This is a diagram showing the configuration of a selection unit in an embodiment.

[0135] The selector 221 can be developed as a combinational circuit with two input gates, and can be accommodated in a single semiconductor device such as a PLD, as long as the number of gate stages and the circuit scale are sufficient. Figure 7 The circuit shown is just an example and is not limited to this.

[0136] Next, functional safety control according to the embodiment will be described.

[0137] Functional safety control command signals CMD are supplied to the power conversion units of the activated groups. For example, the non-safety control unit 30 outputs usage setting signals AD for each group to be activated independently of the functional safety control. The relay units (21 to 24) of each group recognize the activation status based on the usage setting signals AD corresponding to their group.

[0138] 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 sequentially relay the command signal CMD. The activated relay units 21 to 24 relay the command signal CMD to the power conversion units 11 to 14. The power conversion unit 10 supplied with the command signal CMD outputs power. The power conversion unit 10, supplied with the command signal CMD, returns a response signal ANS to the relay unit.

[0139] Furthermore, each relay unit collects the response signals ANS from each activated group of power conversion units, logically combines them, and relays them upstream. If the response signals ANS, resulting from the collection and relaying by each relay unit, are at an L level, functional safety control is functioning normally. If the response signals ANS are at an H level, functional safety control is not functioning normally.

[0140] For example, when any of the relay units collects and relays an H-level response signal ANS, the final response signal ANS supplied to the safety control unit 40 becomes H-level. When the safety control unit 40 is notified of output stoppage based on the command signal CMD, if the collected response signal ANS is H-level, it recognizes that the power conversion units supplied with the command signal CMD include one in which functional safety control is not functioning properly. Upon detecting this, the safety control unit 40 switches the scope of cooperative operation with the non-safety control unit 30 and sets the collected response signal ANS to an L-level state. This identifies the possibility that a power conversion unit excluded from operation may have a problem.

[0141] While a state where functional safety control isn't functioning properly isn't appropriate, it's less likely to cause a serious malfunction. Therefore, following the above sequence, the power conversion unit where functional safety control isn't functioning properly is switched from the active system to the standby system and designated as a target for inspection and maintenance. This approach allows the system to be restored to its desired operating state without shutting down the entire system.

[0142] Furthermore, the relay units 21 to 24 of the group not selected for operation do not relay the command signal CMD to the corresponding power conversion units. The power conversion units not supplied with the command signal CMD are controlled not to output power.

[0143] The above description of the operation focuses on functional safety, but switching between the active system and the standby system for the purpose of avoiding a failure or the like may be performed independently of functional safety.

[0144] According to at least one embodiment described above, a power conversion device includes a first relay unit, one or more second relay units, and a safety control unit. The first relay unit, in a first group associated with a first power conversion unit, transmits a response signal ANS from the first power conversion unit and a response signal ANS from a unit downstream of the first relay unit to an upstream side. The one or more second relay units, in one or more second groups associated with one or more second power conversion units, transmits a response signal ANS from one of the one or more second power conversion units and a response signal ANS from a unit downstream of the one second relay unit to an upstream side of the one second relay unit. The safety control unit is located upstream of the first relay unit and implements functional safety control of the first power conversion unit and the one or more second power conversion units by transmitting control instructions for functional safety control to the first relay unit, thereby monitoring the status of the functional safety control of the first power conversion unit and the one or more second power conversion units. Thus, information indicating the status of functional safety control of a plurality of redundant power conversion units can be collected with a simple configuration.

[0145] The non-safety control unit 30 and the safety control unit 40 may be implemented at least partially as software functional units that are activated by a processor such as a CPU executing a program, or may be implemented entirely as hardware functional units such as an LSI.

[0146] While several embodiments of the present invention have been described, these embodiments are provided as examples and are not intended to limit the scope of the invention. These novel embodiments may be implemented in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and are included in the invention set forth in the claims and their equivalents.

[0147] For example, the three-level ( Figure 2A ) and use the five-level ( Figure 2B ) composition.

[0148] Explanation of symbols

[0149] 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 (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 (synthetic gate circuit).

Claims

1. A power conversion device comprising a plurality of power conversion units divided into a plurality of groups, wherein the operating state of the power conversion units is controlled on a group basis, comprising: a first relay unit, in a first group associated with the first power conversion unit, transmitting a response signal from the first power conversion unit and a response signal from a downstream side of the first relay unit to an upstream side; One or more second relay units, in one or more second groups corresponding to the one or more second power conversion units, respectively, transmit a response signal from one of the one or more second power conversion units and a response signal from a downstream side of the one second relay unit to an upstream side of the one second relay unit; and The safety control unit is arranged on the upstream side of the above-mentioned first relay unit, and implements the functional safety control of the above-mentioned first power conversion unit and the functional safety control of the above-mentioned one or more second power conversion units by transmitting an instruction signal containing a control instruction for functional safety control to the above-mentioned first relay unit, and monitors the status of the functional safety control of the above-mentioned first power conversion unit and the status of the functional safety control of the above-mentioned one or more second power conversion units.

2. The power conversion device according to claim 1, wherein: The safety control unit, the first relay unit, and the one or more second relay units are electrically connected to each other in a connection order based on the order in which they are described, with the safety control unit being designated as the upstream side. Each of the one or more second relay units includes: a first voltage setting circuit that outputs a first signal from the second relay unit to its upstream side; and a second voltage setting circuit that outputs a second signal from the second relay unit to its downstream side. The logic value of the first signal outputted by the second relay unit on the downstream side of the one or more second relay units, the logic value of the third signal generated in the second relay unit, and the logic value of the second signal outputted on the upstream side are determined according to the connection order. The above-mentioned self-second relay unit transmits the response signal generated by the self-power conversion unit related to the above-mentioned self-second relay unit to the upstream side of the self-second relay unit according to the usage setting signal of each second group, and transmits the response signal from the downstream side of the self-power conversion unit to the upstream side of the self-power conversion unit.

3. The power conversion device according to claim 2, wherein: The first relay unit receives the command signal from the safety control unit and supplies it to the first power conversion unit. The above-mentioned one or more second relay units are respectively, when the logic value of the above-mentioned first signal output by the second relay unit on the above-mentioned downstream side and any one of the logic values ​​of the third signal generated in the self-second relay unit, and the logic value of the above-mentioned second signal output on the above-mentioned upstream side are respectively specified values ​​determined according to the above-mentioned connection sequence of the above-mentioned second relay units, according to the usage setting signals of the above-mentioned each second group, the command signal from the upstream side of the above-mentioned self-second relay unit is obtained as a signal for the self-power conversion unit related to the self-second relay unit, and is supplied to the self-power conversion unit respectively.

4. The power conversion device according to claim 2, wherein: The logical value of the first signal and the logical value of the third signal generated in the second relay unit are in a complementary relationship with each other.

5. The power conversion device according to claim 2, wherein: The logic value of the second signal output by the first relay unit is the first logic value H. The logic value of the second signal output by the second relay unit is a second logic value L. The second relay unit located most downstream among the one or more second relay units generates a third signal having the second logical value L in the second relay unit. The second relay units other than the second relay unit disposed most downstream among the two or more second relay units utilize the first signal of the first logical value H outputted by the second relay unit on the downstream side.

6. The power conversion device according to claim 2, wherein: The first relay unit receives the use setting signal of each group from an external device of the first relay unit and relays it to the downstream side. The second relay unit receives the use setting signal of each group from the upstream side and relays the signal to the downstream side.

7. The power conversion device according to claim 1, wherein: The command signal from the safety control unit is made redundant. The first relay unit and the second relay unit each relay the redundant command signal to the downstream side.

8. The power conversion device according to claim 7, wherein: The first relay unit relays the redundant command signal to the first power conversion unit when a predetermined condition is satisfied. The second relay unit relays the redundant command signal to the second power conversion unit when the predetermined condition is satisfied.

9. The power conversion device according to claim 2, wherein: The use setting signal includes first to third use setting signals for selecting the first to third second relay units from the upstream side, respectively.

10. The power conversion device according to claim 9, wherein: The one or more second relay units each include: a selector for selecting any one of the first to third usage setting signals based on a logic value of the first signal and a logic value of the second signal from the second relay unit; an input gate circuit, which limits acquisition of the response signal based on a result of the selection made by the selector; an output gate circuit, which limits relaying of the control instruction based on a result of the selection made by the selector; and The synthesis gate circuit outputs a signal synthesized by synthesizing the response signal from the power conversion unit associated with the second relay unit obtained without being restricted by the input gate circuit and the response signal from the downstream side of the power conversion unit.

11. The power conversion device according to claim 9, comprising: a first selector, configured to select one of the first usage setting signal and the second usage setting signal based on a logic value of the second signal; a second selector that selects one of a selection result of the first selector and the third usage setting signal based on a logical operation result obtained based on a logical value of the first signal, a logical value of the third signal, and a logical value of the second signal; an input gate circuit, which limits acquisition of the response signal based on a result of the selection performed by the second selector; an output gate circuit that limits output of a command signal from the safety control unit based on a result of the selection made by the second selector; and The synthesis gate circuit outputs a signal synthesized by synthesizing the response signal from the power conversion unit associated with the second relay unit obtained without being restricted by the input gate circuit and the response signal from the downstream side of the power conversion unit.

12. The power conversion device according to claim 1, comprising: the first power conversion unit mentioned above; the one or more second power conversion units; and The non-safety control unit adjusts the power conversion amount in the first power conversion unit and the one or more second power conversion units, and performs capacity redundancy control of each power conversion unit.

13. The power conversion device according to claim 1, comprising: the first power conversion unit mentioned above; the one or more second power conversion units; and The non-safety control unit performs standby redundancy control of the power conversion units by outputting a use setting signal for selecting a power conversion unit to be activated from the first power conversion unit and the one or more second power conversion units.

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