Power Conditioner System

Abstract

To provide a power conditioner system that can perform an autonomous operation using power of a mobile body on the basis of a state of a power system in a configuration where a housing accommodating a power conversion circuit and a housing of a power conditioner are independent of each other.SOLUTION: A PCS 100 includes a housing unit 27 (first housing unit) that accommodates an MCU 24 (control unit) for generating communication signals for making a PCS unit 20 (power conditioner) perform an autonomous operation on the basis of a detection value of a system-side voltage sensor 26 (voltage sensor). Additionally, the PCS 100 includes a housing unit 14 (second housing unit) that accommodates an AC / DC converter 11 (power conversion circuit) and an auxiliary input relay 13 (connection relay) and is independent of the housing unit 27. The auxiliary input relay 13 is made into a closed state on basis of a communication signal from the MCU 24 accommodated in the housing unit 27.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power conditioner system. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2020-005341 (Patent Document 1) discloses a power conditioner that is connected to a commercial power grid via a breaker for a battery storage system. The power conditioner can be connected to an electric vehicle with an external power supply function via a V2H stand. Although not explicitly stated in Patent Document 1, the housing of the V2H stand and the housing of the power conditioner are provided independently (separately) from each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-005341 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 does not consider switching the electrical connection state between the power conversion circuit of the V2H station and the electric vehicle. During system operation (grid-connected operation) in which power from the power grid is used, it is desirable to electrically disconnect the power conversion circuit from the electric vehicle to ensure normal use of the power conditioner. On the other hand, by electrically connecting the power conversion circuit and the electric vehicle in the event of an abnormality in the power grid, such as a power outage, it becomes possible for the electric vehicle to operate autonomously using its electric power. Therefore, there is a demand for a power conditioner system in which the housing that houses the power conversion circuit and the housing of the power conditioner are independent of each other, and which is capable of operating autonomously using the electric power of the electric vehicle (mobile object) based on the state of the power grid.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a power conditioner system that is capable of independent operation using power from an electric vehicle (mobile object) based on the state of the power grid, in a configuration in which the housing that houses the power conversion circuit and the housing of the power conditioner are independent of each other. [Means for solving the problem]

[0006] A power conditioner system according to a first aspect of the present disclosure includes a first housing that houses a power conditioner capable of system operation for supplying power from a power grid to a predetermined electrical device, a voltage sensor that detects a voltage in a predetermined electric path between the power conditioner and the power grid, and a control unit that generates a signal for operating the power conditioner in an autonomous mode based on the detected value of the voltage sensor, and a second housing that houses a power conversion circuit that converts power from a mobile object and supplies it to the power conditioner, and a connection relay that can switch the electrical connection state between the mobile object and the power conversion circuit or the power conversion circuit and the power conditioner, and is provided independently of the first housing. The connection relay housed in the second housing is closed based on a signal from the control unit housed in the first housing that is provided independently of the second housing.

[0007] In the power conditioner system according to the first aspect of the present disclosure, as described above, the connection relay housed in the second housing is closed based on a signal (a signal based on the voltage state of the power grid) from the control unit housed in the first housing provided independently of the second housing. This allows for independent operation using power from a mobile object based on the state (voltage state) of the power grid in a configuration in which the housing housing the power conversion circuit and the housing of the power conditioner are independent of each other. [Effects of the Invention]

[0008] According to the present disclosure, in a configuration in which the housing containing the power conversion circuit and the housing of the power conditioner are independent of each other, it is possible to perform autonomous operation using the power of a mobile object based on the state of the power grid. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a configuration of a power conditioner system according to an embodiment. [Figure 2] Fig. 2(A) is a sequence diagram for transitioning from grid-connected operation to isolated operation, and Fig. 2(B) is a sequence diagram for transitioning from isolated operation to grid-connected operation. [Figure 3] FIG. 10 is a control flow diagram when transitioning from grid-connected operation to isolated operation. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0011] FIG. 1 is a diagram showing the configuration of a PCS (Power Conditioning System) 100 according to this embodiment.

[0012] 1, the PCS 100 includes an AC / DC unit 10 and a PCS unit 20. The PCS unit 20 is an example of the "power conditioner" of the present disclosure.

[0013] The AC / DC unit 10 includes an AC / DC converter 11, an MCU (Micro Controller System) 12, an auxiliary input relay 13, and a housing 14. The housing 14 houses the AC / DC converter 11, the MCU 12, and the auxiliary input relay 13. The AC / DC converter 11 and the auxiliary input relay 13 are examples of a "power conversion circuit" and a "connection relay" in the present disclosure, respectively. The housing 14 is an example of a "second housing" in the present disclosure.

[0014] AC / DC converter 11 converts AC power from electric vehicle 200 into DC power and supplies it to PCS unit 20. Note that electric vehicle 200 can supply power to AC / DC unit 10 by inserting power feed cable 15 of AC / DC unit 10. Note that electric vehicle 200 is an example of a "mobile body" in the present disclosure. Furthermore, electric vehicles may include not only automobiles but also motorcycles and the like.

[0015] Auxiliary input relay 13 is configured to be able to switch the electrical connection state between electric vehicle 200 and AC / DC converter 11. Specifically, when auxiliary input relay 13 is in a closed state, electric vehicle 200 and AC / DC converter 11 are electrically connected. When auxiliary input relay 13 is in an open state, electric vehicle 200 and AC / DC converter 11 are electrically disconnected. Note that auxiliary input relay 13 may be provided on the PCS unit 20 side of AC / DC converter 11, and may be able to switch the electrical connection state between AC / DC converter 11 and PCS unit 20.

[0016] The MCU 12 controls the open / closed state of the auxiliary input relay 13 by sending a signal to the auxiliary input relay 13 .

[0017] PCS unit 20 is configured to be capable of grid-connected operation, supplying AC power from power grid 300 to electrical appliances 401 in home 400. Note that PCS unit 20 may also supply power to electrical appliances other than home 400 (for example, commercial buildings, etc.). Furthermore, electrical appliances 401 are an example of "predetermined electrical appliances" in the present disclosure. Furthermore, grid-connected operation is an example of "system operation" in the present disclosure.

[0018] The PCS unit 20 includes a DC / DC converter 21, an inverter 22, a grid-connection relay 23, an MCU 24, an input-side voltage sensor 25, a grid-side voltage sensor 26, and a housing 27. The housing 27 houses the DC / DC converter 21, the inverter 22, the grid-connection relay 23, the MCU 24, the input-side voltage sensor 25, and the grid-side voltage sensor 26. The grid-side voltage sensor 26 and the MCU 24 are examples of a "voltage sensor" and a "control unit," respectively, in the present disclosure. The housing 27 is an example of a "first housing" in the present disclosure.

[0019] DC / DC converter 21 boosts the DC voltage from AC / DC converter 11. DC / DC converter 21 also boosts the DC voltage from solar power generation system 500, for example.

[0020] The inverter 22 converts the DC voltage (power) from the DC / DC converter 21 into an AC voltage (power). The input voltage sensor 25 detects the voltage of an electric path electrically connecting the DC / DC converter 21 and the inverter 22.

[0021] The grid-connection relay 23 is configured to be able to switch the electrical connection state between the inverter 22 and the power system 300. Specifically, when the grid-connection relay 23 is in a closed state, the inverter 22 and the power system 300 are electrically connected. In this case, grid-connected operation is performed in which power from the power system 300 (and power from the inverter 22) is supplied to the electrical device 401. When the grid-connection relay 23 is in an open state, the inverter 22 and the power system 300 are electrically disconnected. In this case, isolated operation is performed in which power from the power system 300 is not supplied to the electrical device 401, and only power from the PCS unit 20 (inverter 22) is supplied to the electrical device 401.

[0022] The grid-side voltage sensor 26 detects the voltage in a predetermined electrical path on the power grid 300 side (downstream side) of the PCS unit 20. Specifically, the grid-side voltage sensor 26 detects the voltage in an electrical path 26a between the inverter 22 and the grid-connection relay 23.

[0023] Furthermore, the housing 14 and the housing 27 are provided independently of each other. In other words, the housing 14 and the housing 27 are provided separately from each other (as separate members).

[0024] The MCU 24 controls the open / closed state of the interconnection relay 23 by transmitting a signal to the interconnection relay 23. The MCU 24 is also configured to be able to communicate with the MCU 12 of the AC / DC unit 10. The MCU 24 and the MCU 12 communicate with each other via a communication line 24a. The communication line 24a connects the MCUs (12, 24) in housings independent from each other. The MCU 24 and the MCU 12 may also communicate with each other wirelessly.

[0025] Furthermore, the MCU 24 generates a signal for operating the PCS unit 20 in an autonomous mode based on the detected value of the grid-side voltage sensor 26. Specifically, the MCU 24 generates the signal when the detected value of the grid-side voltage sensor 26 becomes 0 (or a value close to 0) during a power outage in the power grid 300. Of the above signals, the signal transmitted to the MCU 12 is referred to as a communication signal.

[0026] Here, in conventional power conditioner systems, in a configuration in which the housing part 14 of the AC / DC unit 10 and the housing part 27 of the PCS unit 20 are independent of each other, it has been desirable to perform autonomous operation using the power of the electric vehicle 200 based on the state of the power grid 300.

[0027] Therefore, in this embodiment, the auxiliary input relay 13 housed in the housing part 14 is closed based on a communication signal from the MCU 24 housed in the housing part 27 provided independently of the housing part 14.

[0028] Specifically, the MCU 24 transmits the communication signal to the MCU 12 in the housing 14 via the communication line 24a. Upon receiving the communication signal, the MCU 12 transmits a signal to the auxiliary input relay 13 to close the auxiliary input relay 13. The MCU 24 also transmits the signal to the grid-connection relay 23 to open the grid-connection relay 23.

[0029] 2(A) shows a sequence for changing the operating state of the PCS 100 from grid-connected operation to stand-alone operation. Assume that the power grid 300 experiences a power outage at time t1. In this case, the MCU 24 opens (turns off) the grid-connected relay 23 at time t1 based on a change in the detected value of the grid-side voltage sensor 26. At the same time as opening the grid-connected relay 23, the MCU 24 turns off the inverter 22. This ends the grid-connected operation.

[0030] Next, at time t2, a predetermined time (for example, 5 seconds) after time t1, MCU 24 starts a welding check of interconnection relay 23. MCU 24 performs a welding check of interconnection relay 23 from time t2 to time t3, a predetermined time (for example, 5 seconds) after time t2. In the welding check, it is confirmed that the detection value of input side voltage sensor 25 is 300 V or higher.

[0031] Next, at time t3, the MCU 24 transmits a communication signal to the MCU 12 of the AC / DC unit 10 through the communication line 24a. As a result, at time t4, which is a predetermined communication delay time (for example, 0.3 seconds) after time t3, the auxiliary input relay 13 is closed (ON). Also, at time t3, the MCU 24 turns on the inverter 22. This starts the autonomous operation. That is, the period from time t1 to time t3 is a preparation period for the autonomous operation. Note that in the example shown in FIG. 2(A), the input from the electric vehicle 200 to the AC / DC converter 11 (see "auxiliary input" in FIG. 2(A)) is always ON.

[0032] 2(B) shows a sequence for changing the operating state of the PCS 100 from isolated operation to grid-connected operation. Assume that the power grid 300 recovers from a power outage at time t11. In this case, the MCU 24 turns off the communication signal being sent to the MCU 12 at time t11 based on a change in the detected value of the grid-side voltage sensor 26. As a result, the auxiliary input relay 13 is opened (turned off) at time t12, a predetermined communication delay time (e.g., 0.3 seconds) after time t11. The MCU 24 also turns off the inverter 22 at time t11. As a result, the isolated operation ends.

[0033] Next, at time t13, the MCU 24 closes (turns on) the grid-connected relay 23 and turns on the inverter 22. This starts grid-connected operation. That is, the period from time t11 to time t13 is a preparation period for grid-connected operation.

[0034] Time t13 is later than time t12. This prevents the auxiliary input relay 13 and the interconnection relay 23 from being closed (on) at the same time.

[0035] FIG. 3 is a control flow diagram showing the control of the MCU 24 when shifting from grid-connected operation to independent operation.

[0036] First, in step S1, an abnormality (e.g., a power outage) in the power grid 300 is detected based on the detection value of the grid-side voltage sensor 26. Next, in step S2, the grid-connected operation is stopped by opening (turning off) the grid-connected relay 23 and turning off the inverter 22. Next, in step S3, an initialization process for the isolated operation mode is performed.

[0037] Here, in step S3, steps S4 and S5 are performed. In step S4, it is determined whether or not an error occurred in the initialization process in step S3. If an error occurred (if Yes), the process proceeds to step S40. If no error occurred (if No), the process proceeds to step S5. In step S5, it is determined whether or not a manual operation to stop the operation of PCS100 has been performed. If a stop operation has been performed (if Yes), the process proceeds to step S50. If a stop operation has not been performed (if No), the process proceeds to step S6. Note that steps S4 and S5 may be performed in the reverse order or simultaneously. Furthermore, the processes of steps S4 and S5 are collectively referred to as process A.

[0038] In step S6, a welding check is performed on the interconnection relay 23. In step S60 in step S6, the above-described process A is performed.

[0039] Next, in step S7, the auxiliary input relay 13 is closed (turned on). In step S70 in step S7, the above-described process A is performed.

[0040] Next, in step S8, a communication signal is sent to the MCU 12 and the inverter 22 is turned on, thereby starting the self-sustained operation. In step S80 of step S8, the above-mentioned process A is performed. If the results of steps S4 and S5 in process A of step S80 are both No, the process ends.

[0041] Furthermore, in step S40, error processing is performed. In step S41 in step S40, it is determined whether or not automatic recovery is possible for the operation of the PCS 100. If automatic recovery is possible (if Yes), the process returns to step S3. If automatic recovery is not possible (if No), the process proceeds to step S5. If the answer is Yes in step S5 in step S40, the process proceeds to step S50. If the answer is No in step S5 in step S40, the process proceeds to step S42. Note that the order of steps S41 and S5 may be reversed or they may be performed simultaneously.

[0042] In step S42, the state of the PCS 100 is changed to the failure mode. Then, the process ends. In step S50, the operation of the PCS 100 is stopped. Then, the process returns to step S3.

[0043] As described above, in this embodiment, the auxiliary input relay 13 housed in the housing 14 is closed based on a communication signal from the MCU 24 housed in the housing 27 that is provided independently of the housing 14. This allows the auxiliary input relay 13 to be controlled by a communication signal from the MCU 24 housed in a housing different from that of the auxiliary input relay 13.

[0044] In addition, in the above embodiment, an example has been described in which the MCU 24 of the PCS unit 20 controls the auxiliary input relay 13 via the MCU 12 of the AC / DC unit 10, but the present disclosure is not limited to this. The MCU 24 may directly control the auxiliary input relay 13 without going through the MCU 12.

[0045] In addition, in the above embodiment, an example has been shown in which the AC / DC unit 10 is provided in the power conditioner system 100, but the present disclosure is not limited to this. Instead of the AC / DC unit, a unit to which DC (direct current power) is input may be provided.

[0046] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0047] 11 AC / DC converter (power conversion circuit), 13 auxiliary input relay (connection relay), 14 housing part (second housing part), 20 PCS unit (power conditioner), 24 MCU (control part), 26 grid side voltage sensor (voltage sensor), 26a electric circuit (predetermined electric circuit), 27 housing part (first housing part), 100 power conditioner system, 200 electric vehicle (moving object), 300 power system, 401 electric equipment (predetermined electric equipment).

Claims

1. a first housing that houses a power conditioner capable of system operation for supplying power from a power system to a predetermined electrical device; a voltage sensor that detects a voltage in a predetermined electric circuit on the power system side of the power conditioner; a control unit that generates a signal for operating the power conditioner in an independent manner based on a detected value of the voltage sensor; and a first connection relay that can switch an electrical connection state between the power system and the power conditioner; a second housing portion that houses a power conversion circuit that converts power from a mobile object and supplies the converted power to the power conditioner, and a second connection relay that can switch an electrical connection state between the mobile object and the power conversion circuit or an electrical connection state between the power conversion circuit and the power conditioner, and that is provided independently of the first housing portion; A power conditioner system, wherein the second connection relay housed in the second housing unit is closed based on the signal from the control unit housed in the first housing unit, which is provided independently of the second housing unit.

2. The power conditioner system of claim 1, wherein the control unit opens the first connection relay when the power grid experiences a power outage, and closes the second connection relay a predetermined time after the first connection relay is opened.

3. A power conditioner system as described in Claim 2, wherein the control unit performs a welding check of the first connection relay during the specified time.

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