WO2020022194A1 - Power conditioner - Google Patents

Abstract

The present invention provides a power conditioner that, without requiring an additional structure, is able to detect the attachment state of a current sensor attached to an electrical wire that connects an electric power system and the power conditioner. This power conditioner (10) has: a power conversion device (14) that can convert electric power outputted by an electrical storage device (3) to a prescribed DC power; an inverter unit (12) that can convert DC power to AC power and output the AC power; a first current sensor (16) for detecting output current of the inverter unit (12); and an assessment unit (22) that assesses the attachment state of a second current sensor (8) on the basis of a first current value detected by the first current sensor (16), and a second current value detected by the second current sensor (8), which is attached to a first electrical wire (4A).

Description

Power conditioner

The present disclosure relates to a power conditioner.

(2) There is known a system including a power conditioner that converts DC power of a power generation device such as a solar power generation device into AC power and supplies power to an indoor AC load in connection with a power system. In such a system, the power conditioner and the power system are configured to detect a state in which power is supplied from the power system to the indoor AC load and a state in which reverse power flows from the power conditioner to the power system in order to buy and sell power. A current sensor is provided for each of the U-phase wire and the W-phase wire in the single-phase three-wire wire between the two. In such a system, the current sensor may be mounted in the wrong direction. For this reason, there has been proposed a device that includes an internal power load, determines a mounting error of a current sensor by connecting a wire to the internal power load by a connection mechanism, and flowing a current through the internal power load (for example, see Patent Document 1). Reference 1).

International Publication WO2011 / 093109

By the way, in the system as described above, an internal power load and a connection mechanism provided in the power conditioner are necessary in order to determine a mounting error of the current sensor mounted on each of the U-phase wire and the W-phase wire. Therefore, the number of components of the power conditioner increases. Note that such a problem is not limited to a single-phase three-wire power system, but also occurs in a single-phase two-wire power system.

目的 An object of the present disclosure is to provide a power conditioner that does not require an additional configuration and that can detect an attached state of a current sensor attached to an electric wire connecting a power system and a power conditioner.

A power conditioner according to an embodiment of the present disclosure is a power conditioner that is connected to a single-phase two-wire power system including a first electric wire and a second electric wire, and is output by a DC power supply device. A conversion unit capable of converting power to predetermined DC power, an inverter unit capable of converting the DC power to AC power and outputting the converted power, a first current sensor for detecting an output current of the inverter unit, Judgment for judging the attachment state of the second current sensor based on a first current value detected by one current sensor and a second current value detected by a second current sensor attached to the first electric wire. And a part.

(4) Since the combined power of the output power of the inverter unit and the power from the power system is supplied to the indoor AC load, the direction of fluctuation of the output power of the inverter unit and the direction of fluctuation of the power from the power system are opposite. That is, when the power consumption of the indoor AC load is constant, when the output power of the inverter unit increases, the power from the power system decreases, and when the output power of the inverter unit decreases, the power from the power system increases. Further, the power from the power system can be grasped from the second current value of the second current sensor.

Here, assuming that the direction in which the second current sensor is mounted is normal as the direction in which the second current sensor is mounted such that the direction in which the output power of the inverter unit fluctuates and the direction in which the power from the power system fluctuates are opposite. When the mounting direction of the second current sensor is opposite, the direction of fluctuation of the output power of the inverter unit and the direction of fluctuation of the power from the power system are the same. As described above, it is possible to determine the mounting direction of the second current sensor from the relationship between the direction of fluctuation of the output power of the inverter unit and the direction of fluctuation of power from the power system. Further, when the second current sensor is disconnected, the second current sensor does not output a signal corresponding to the fluctuation of the power from the power system even if the output power of the inverter unit fluctuates. In this manner, it can be determined that the second current sensor is disconnected according to the amount of change in the output power of the inverter and the amount of change in the power from the power system.

In view of this point, the present power conditioner determines the mounting state of the second current sensor based on the first current value detected by the first current sensor and the second current value detected by the second current sensor. By doing so, an additional configuration is not required, and the attachment state of the current sensor attached to the electric wire connecting the power system and the power conditioner can be detected.

A power conditioner according to an embodiment of the present disclosure is a power conditioner interconnected to a single-phase three-wire power system including a first electric wire, a second electric wire, and a third electric wire serving as a neutral wire. A conversion unit that can convert the power output from the DC power supply into predetermined DC power, an inverter that can convert the DC power to AC power and output the power, and detect an output current of the inverter. Current sensor, a first current value detected by the first current sensor, and a second current detected by a second current sensor attached to each of the first electric wire and the second electric wire A determination unit that determines the mounting state of the second current sensor based on the value.

According to this configuration, the attachment state of the second current sensor is determined based on the first current value detected by the first current sensor and the second current value detected by the second current sensor. This eliminates the need for a configuration, and can detect the mounting state of the current sensor that is mounted on the electric wire that connects the power system and the power conditioner.

According to the power conditioner according to an embodiment of the present disclosure, an additional configuration is not required, and it is possible to detect an attached state of a current sensor attached to an electric wire connecting the power system and the power conditioner.

FIG. 1 is a configuration diagram of a power management system in which a power conditioner according to a first embodiment is used. FIG. 2 is a circuit diagram of an inverter section of the power conditioner and its periphery. 4 is a graph showing an example of changes in output power of an inverter unit and purchased power from a power system. 9 is a flowchart illustrating an example of a procedure of a process performed by a determination unit of the power conditioner to determine an attachment state of a second current sensor. FIG. 4 is a schematic circuit diagram for explaining a relationship between output power of the inverter unit and power from the power system before the output power of the inverter unit fluctuates. FIG. 4 is a schematic circuit diagram for explaining the relationship between the output power of the inverter unit and the power from the power system after the output power of the inverter unit has changed. FIG. 7 is a schematic circuit diagram for explaining a relationship between output power of an inverter unit of another example and power from a power system. The block diagram of the power management system using the power conditioner of 2nd Embodiment. FIG. 2 is a circuit diagram of an inverter section of the power conditioner and its periphery. 9 is a flowchart illustrating an example of a procedure of a process performed by a determination unit of the power conditioner to determine an attachment state of a second current sensor. FIG. 4 is a schematic circuit diagram for explaining a relationship between output power of the inverter unit and power from the power system before the output power of the inverter unit fluctuates. FIG. 4 is a schematic circuit diagram for explaining the relationship between the output power of the inverter unit and the power from the power system after the output power of the inverter unit has changed.

Hereinafter, each embodiment will be described with reference to the drawings.
(1st Embodiment)
As shown in FIG. 1, the power management system 1 includes a power conditioner 10, a solar power generation device 2 electrically connected to the power conditioner 10, and a power storage device 3 which is an example of a DC power supply device. Power conditioner 10 is connected to power system 5 via AC bus 4. The power conditioner 10 of the present embodiment is connected to a single-phase two-wire power system 5 including a first electric wire 4A and a second electric wire 4B as the AC bus 4. A load 6 is connected to the AC bus 4 via a distribution board (not shown) or the like. The load 6 is, for example, an indoor AC load, and includes a lighting, a refrigerator, a washing machine, an air conditioner, a microwave oven, and the like. The power management system 1 adjusts power between the solar power generation device 2, the power storage device 3, the power system 5, and the load 6 by the power conditioner 10. As an example of this adjustment, the reverse power flow of the power generated by the photovoltaic power generator 2 to the power system 5, the power storage in the power storage device 3, the adjustment of the supply to the load 6, and the power storage device of the power in the power system 5 3 and adjustment of supply to the load 6. As the power generation device, for example, a wind power generation device, a gas power generation device, a geothermal power generation device, or the like can be used in addition to the solar power generation device.

The photovoltaic power generation device 2 has a photovoltaic power generation panel (not shown), and supplies the DC power generated by the photovoltaic power generation panel to the power conditioner 10. The photovoltaic power generation device 2 executes a maximum power point tracking control (MPPT: Maximum Power Point Tracking) that extracts a current at an output voltage at which the power output from the photovoltaic panel becomes maximum.

Power storage device 3 includes a plurality of storage batteries connected in series. Power conditioner 10 controls charging and discharging of power storage device 3.
The power conditioner 10 includes a PV converter 11, an inverter unit 12, a voltage sensor 13, a power conversion device 14 as an example of a conversion unit, and a control device 20. The PV converter 11, the inverter unit 12, and the power converter 14 are each connected to a high-voltage DC bus 15. That is, the PV converter 11, the inverter unit 12, and the power converter 14 are connected to each other via the high-voltage DC bus 15. The notification unit 7 is electrically connected to the power conditioner 10. The notification unit 7 notifies the outside of the power conditioner 10 of predetermined information. Examples of the notification means by the notification unit 7 include light emission (light emission color, blinking), sound, and display by the display unit.

The solar power generation device 2 is connected to the PV converter 11. The PV converter 11 outputs the photovoltaic power generator 2 that fluctuates according to the sunshine conditions such as the season, weather, and time zone to the high-voltage DC bus 15 by the maximum power point tracking control (MPPT). An example of the set voltage output from the PV converter 11 to the high-voltage DC bus 15 is 380V. Inverter unit 12 is connected to PV converter 11 and AC bus 4. The inverter unit 12 is a DC / AC converter (DC / AC converter), and converts the DC power of the high-voltage DC bus 15 into, for example, an effective value of 200 V AC power and outputs the AC power to the AC bus 4. The inverter unit 12 converts the AC power of the AC bus 4 into DC power of a set voltage and outputs the DC power to the high-voltage DC bus 15.

(2) As shown in FIG. 2, the inverter section 12 is a full-bridge type inverter circuit and has four switch elements 12a to 12d. The switch elements 12a and 12b are connected in series between a first electric wire 15H and a second electric wire 15L constituting the high-voltage DC bus 15. The switch elements 12c and 12d are connected in series between the first electric wire 15H and the second electric wire 15L. The switch elements 12a and 12b and the switch elements 12c and 12d are connected in parallel.

The inverter unit 12 includes a third wire 12X connected to a connection node N1 between the switch element 12a and the switch element 12b, and a fourth wire connected to a connection node N2 between the switch element 12c and the switch element 12d. 12Y. The third electric wire 12X and the fourth electric wire 12Y are connected to a pair of input / output terminals 10T of the power conditioner 10. A first electric wire 4A and a second electric wire 4B of the AC bus 4 are connected to the pair of input / output terminals 10T. The third wire 12X is provided with an inductor 17X, and the fourth wire 12Y is provided with an inductor 17Y. A smoothing capacitor 18 and a voltage sensor 13 are provided between the third electric wire 12X and the fourth electric wire 12Y. The voltage sensor 13 outputs a signal corresponding to the output voltage of the inverter unit 12, which is the voltage of the third electric wire 12X and the fourth electric wire 12Y.

The inverter unit 12 has a first current sensor 16 for detecting a current output from the inverter unit 12. More specifically, the first current sensor 16 is provided on the third electric wire 12X, and outputs a signal corresponding to the current flowing through the third electric wire 12X.

As shown in FIG. 2, a second current sensor 8 is provided in a portion between the load 6 and the power system 5 on the AC bus 4. In the present embodiment, the second current sensor 8 is attached to the first electric wire 4A of the AC bus 4. The second current sensor 8 outputs a signal corresponding to the current flowing through the first electric wire 4A.

電 Power storage device 3 is connected to power conversion device 14. Power conversion device 14 converts the power (DC power) output from power storage device 3 into predetermined DC power. The power converter 14 outputs a predetermined DC power to the inverter unit 12. One example of the power converter 14 is a DC-DC converter. Power conversion device 14 converts the power output from power storage device 3 into DC power of a predetermined voltage and outputs the DC power to inverter unit 12.

As illustrated in FIG. 1, the control device 20 includes a control unit 21 that controls the PV converter 11, the inverter unit 12, and the power conversion device 14, and a determination unit 22 that determines a mounting state of the second current sensor 8. .

The control unit 21 is electrically connected to the gates (control terminals) of the switch elements 12a to 12d via a drive circuit (not shown), and sends a control signal for controlling on / off of the switch elements 12a to 12d to the gates of the switch elements 12a to 12d. Output to Control unit 21 includes an arithmetic processing unit that executes a predetermined control program. The arithmetic processing device includes, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The control unit 21 may include one or more microcomputers. The control unit 21 may include a plurality of arithmetic processing devices that are separately arranged at a plurality of locations. Control unit 21 further includes a storage unit. The storage unit stores various control programs and information used for various control processes. The storage unit includes, for example, a nonvolatile memory and a volatile memory.

The determination unit 22 includes an A / D converter 23 and a DSP (Digital Signal Processor) 24. The A / D converter 23 is electrically connected to the first current sensor 16, the second current sensor 8, and the voltage sensor 13. The first current sensor 16 outputs an analog signal corresponding to the amount of current flowing through the third electric wire 12X. The second current sensor 8 outputs an analog signal according to the amount of current flowing through the first electric wire 4A. The voltage sensor 13 outputs an analog signal according to the output voltage of the inverter unit 12. The A / D converter 23 converts an output signal of the first current sensor 16 into a first current value TA1. Further, the A / D converter 23 converts the output signal of the second current sensor 8 into a second current value TA2. Further, the A / D converter 23 converts the output signal of the voltage sensor 13 into a voltage value TV. The A / D converter 23 outputs the converted values TA1, TA2, and TV to the DSP 24. In the present embodiment, the DSP 24 takes in the first current value TA1, the second current value TA2, and the voltage value TV, performs a differentiation process using a digital filter, and performs the second current sensor 8 based on the processed value. Determine the state of attachment. More specifically, in a state where the first current value TA1 detected by the first current sensor 16 and the second current value TA2 detected by the second current sensor 8 are synchronized, the respective increasing / decreasing directions are detected, Whether the value has increased (+) or decreased (-) is calculated by a differentiation process using a digital filter, and the product of the first current value TA1 and the second current value TA2 is positive (+) or negative (-). The attachment state of the second current sensor 8 is determined based on either of them.

In the power management system 1 having such a configuration, since the load 6 is supplied with at least one of the output power from the inverter unit 12 and the purchased power from the power system 5, when the power consumption of the load 6 is constant, The output power of the inverter unit 12 and the purchased power from the power system 5 fluctuate in conjunction with each other. In one example, as shown in FIG. 3, when the output power of the inverter unit 12 decreases, the purchased power from the power system 5 increases, and when the output power of the inverter unit 12 increases, the purchased power from the power system 5 increases. Decrease. That is, the direction of fluctuation of the power purchased from the power system 5 detected by the output signal of the normally installed second current sensor 8 is opposite to the direction of fluctuation of the output power of the inverter unit 12.

The power purchased from the power system 5 is calculated based on the second current value TA2 detected by the second current sensor 8. Since the direction in which the alternating current flows cannot be specified only by the current value detected by the current sensor, the phase difference from the output voltage value of the inverter unit 12 detected by the voltage sensor 13 is actually detected, and the product ( By calculating the power value, the power value and its direction (whether to sell or buy) are detected. On the other hand, since the second current sensor 8 is connected to the AC bus 4 by the installer, the mounting direction of the second current sensor 8 to the AC bus 4 may be incorrect. Further, even if the second current sensor 8 is normally attached, the second current sensor 8 may be detached from the AC bus 4 due to, for example, aging. When the mounting direction of the second current sensor 8 is incorrect or the second current sensor 8 is deviated from the AC bus 4, the purchase from the power system 5 in the direction in which the output power of the inverter unit 12 fluctuates. It is detected that the fluctuation direction of the electric power is different from the fluctuation direction when the mounting direction of the second current sensor 8 is normal, or that the purchased power from the power system 5 does not fluctuate.

Therefore, the determination unit 22 of the present embodiment monitors the output power of the inverter unit 12 and the purchased power from the power system 5, and when the output power of the inverter unit 12 fluctuates, the output power of the inverter unit 12 and the power system 5, the state of attachment of the second current sensor 8 is determined. Here, the attachment state of the second current sensor 8 includes whether or not the attachment direction of the second current sensor 8 to the AC bus 4 is normal and whether or not the second current sensor 8 is off the AC bus 4.

On the other hand, the output power of the inverter unit 12 may slightly fluctuate due to the influence of noise or the like. When the output power of the inverter unit 12 fluctuates due to noise or the like, the power purchased from the power system 5 may not fluctuate in conjunction therewith, and the mounting state of the second current sensor 8 may be erroneously determined. For this reason, the determination unit 22 of the present embodiment determines the mounting state of the second current sensor 8 when the amount of fluctuation per unit time of the output power of the inverter unit 12 is equal to or greater than a predetermined value VX. Here, the predetermined value VX is a value larger than the maximum value of the fluctuation of the output power of the inverter unit 12 due to noise or the like, and is set in advance by a test or the like.

FIG. 4 is a flowchart illustrating an example of a procedure of a determination process of the attachment state of the second current sensor 8 performed by the determination unit 22. The determining unit 22 starts the process when the power is supplied to the control device 20 and repeatedly executes the process at predetermined intervals until the power supply to the control device 20 is stopped. In the following description of the flowchart, the fluctuation direction and the fluctuation amount of the purchased power are calculated based on the output signal of the second current sensor 8, and are different from the actual fluctuation direction and the fluctuation amount in the AC bus 4.

The determination unit 22 determines in step S11 whether the amount of change in the output power of the inverter unit 12 per unit time is equal to or greater than a predetermined value VX. The determination unit 22 calculates the amount of change in the output power of the inverter unit 12 per unit time. In one example, the determination unit 22 calculates the difference between the minimum value and the maximum value of the output power of the inverter unit 12 per unit time as the amount of change in the output power of the inverter unit 12 per unit time. The unit time is a time for determining that a change in output power of the inverter unit 12 is not a change in output power due to noise or the like, and is set in advance by a test or the like. In one example, the unit time is a time that is one cycle (for example, 1/50 (s) or 1/60 (s)) of the AC power of the power system 5. In the present embodiment, the unit time is set to 10 (ms), and the predetermined value VX is set to 200 (W).

The output power of the inverter unit 12 is calculated by the product of the first current value TA1 detected by the first current sensor 16 and the voltage value TV detected by the voltage sensor 13. The output power of the inverter unit 12 is such that the voltage value TV detected by the voltage sensor 13 and the first current value TA1 detected by the first current sensor 16 are both sinusoidal. Classified as Since the phase difference between the voltage value TV and the first current value TA1 fluctuates depending on the load 6, it is calculated by multiplying the phase difference to obtain an accurate power value. However, in order to determine the mounting state of the second current sensor 8, it is necessary to determine whether the increasing and decreasing directions are the same or different from each other in a state where the first current value TA1 and the second current value TA2 are synchronized. Since it can be determined if possible, it is not always necessary to determine the power value. For this reason, the process of step S11 can be said to be a determination as to whether or not the amount of change in the output current per unit time of the inverter unit 12 is equal to or greater than a predetermined value AX. That is, it can be said that the process of step S11 is a determination of whether or not the amount of change per unit time of the first current value TA1 detected by the first current sensor 16 is equal to or greater than the predetermined value AX. Here, the predetermined value AX is a value for determining that the change in the output current of the inverter unit 12 is not a change in the output current due to noise or the like, and is set in advance by a test or the like. One example of the determination value is 1 (A).

If the fluctuation amount per unit time of the output power of the inverter unit 12 is not equal to or larger than the predetermined value VX in step S11 (step S11: NO), the determination unit 22 ends the process once. That is, when the amount of change in the first current value TA1 per unit time is less than the predetermined value AX, the determination unit 22 ends the process once.

When the variation per unit time of the output power of the inverter 12 is equal to or more than the predetermined value VX (step S11: YES), the determination unit 22 determines in step S12 that the variation of the purchased power from the power system 5 is the predetermined value. It is determined whether or not VX or more. Note that the process of step S12 can also be said to be a determination of whether or not the amount of change in current per unit time supplied from the power system 5 to the first electric wire 4A is equal to or greater than a predetermined value AX. That is, it can be said that the process of step S12 is a determination of whether or not the variation per unit time of the second current value TA2 detected by the second current sensor 8 is equal to or greater than the predetermined value AX.

The determination unit 22 calculates, for example, the difference between the minimum value and the maximum value of the power purchased from the power system 5 per unit time as the fluctuation amount of the power purchased from the power system 5 per unit time. The purchased power from the power system 5 is the product of the second current value TA2 detected by the second current sensor 8 and the voltage value between the first electric wire 4A and the second electric wire 4B of the AC bus 4. Is calculated by In the process of step S12, instead of the predetermined value VX, a predetermined value VY (0 <VY <VX) larger than 0 and smaller than the predetermined value VX is used to obtain the power purchased from the power system 5. It may be determined whether or not the amount of change per unit time is equal to or greater than a predetermined value VY.

If the variation per unit time of the power purchased from the power system 5 is equal to or greater than the predetermined value VX (step S12: YES), the determination unit 22 determines in step S13 the variation in the output power of the inverter unit 12 per unit time. It is determined whether the direction is opposite to the direction in which the power purchased from the power system 5 fluctuates per unit time. In one example, the determination unit 22 defines the direction in which the power increases as plus and defines the direction in which the power decreases as negative, the fluctuation direction of the output power of the inverter unit 12 per unit time, and the power purchased from the power system 5. Are set as either plus or minus, respectively. The determining unit 22 multiplies the direction of change per unit time of the output power of the inverter unit 12 by the direction of change per unit time of the power purchased from the power system 5 to determine whether the result of the multiplication is negative. Is determined. When the result of the multiplication is negative, the determination unit 22 determines that the direction of change in the output power of the inverter unit 12 per unit time is opposite to the direction of the change in the power purchased from the power system 5 per unit time. judge. In one example, when the output power of the inverter unit 12 increases (plus) and the purchased power from the power system 5 decreases (minus), the determination unit 22 calculates plus and minus. The determination unit 22 determines that the fluctuation direction of the output power of the inverter unit 12 per unit time is opposite to the fluctuation direction of the power purchased from the power system 5 per unit time because the calculation result is negative. . Note that the process of step S13 is performed by changing the direction of change of the first current value TA1 per unit time when the amount of change per unit time of the first current value TA1 is equal to or more than the predetermined value AX and the second current value TA2. It can also be said that it is determined whether or not the direction of change per unit time is opposite.

If the fluctuation direction of the output power of the inverter unit 12 per unit time is opposite to the fluctuation direction of the purchased power from the power system 5 per unit time (step S13: YES), the determination unit 22 determines in step S14. It is determined that the mounting direction of the second current sensor 8 is normal, and the process is temporarily terminated. That is, the determination unit 22 determines the mounting direction of the second current sensor 8 based on the direction of change of the first current value TA1 per unit time and the direction of change of the second current value TA2 per unit time. In the present embodiment, when the direction of change of the first current value TA1 per unit time is opposite to the direction of change of the second current value TA2 per unit time, the determination unit 22 attaches the second current sensor 8 It is determined that the direction is normal.

On the other hand, when the fluctuation direction of the output power of the inverter unit 12 per unit time is the same as the fluctuation direction of the purchased power from the power system 5 per unit time (step S13: NO), In step S15, it is determined that the mounting direction of the second current sensor 8 is abnormal. In the present embodiment, when the direction of change of the first current value TA1 per unit time is the same as the direction of change of the second current value TA2 per unit time, the determination unit 22 It is determined that the mounting direction is abnormal.

The determination unit 22 outputs to the notification unit 7 that the mounting direction of the second current sensor 8 is abnormal in the process of step S15. In one example, the notification unit 7 has a display unit such as a liquid crystal panel. The notification unit 7 displays on the display unit that the mounting direction of the second current sensor 8 is abnormal. For example, when the installer constructs the power management system 1, by visually recognizing the display unit of the notification unit 7, it is possible to recognize that the mounting direction of the second current sensor 8 is abnormal.

When the fluctuation amount per unit time of the power purchased from the power system 5 is less than the predetermined value VX (step S12: NO), the determination unit 22 disconnects the second current sensor 8 from the AC bus 4 in step S16. Is determined, and the process is temporarily terminated. As described above, the determination unit 22 determines that the second current sensor 8 is out of the AC bus 4 when the variation amount of the second current value TA2 per unit time is less than the predetermined value AX. In one example, when the variation amount of the first current value TA1 per unit time is equal to or more than the predetermined value AX and the second current value TA2 does not fluctuate over the unit time, the determination unit 22 determines that the second current sensor 8 Is determined to be out of the AC bus 4. The determination unit 22 outputs to the notification unit 7 that the second current sensor 8 is out of the AC bus 4 in the process of step S16. In one example, the notification unit 7 displays on the display unit that the second current sensor 8 is out of the AC bus 4.

An embodiment of the process of determining the mounting state of the second current sensor 8 will be described with reference to FIGS. FIG. 5 shows a state before the output power of the inverter unit 12 fluctuates, and FIG. 6 shows a state after the output power of the inverter unit 12 fluctuates. 5 and 6, the power consumption of the load 6 is defined as 300 W.

As shown in FIG. 5, when 200 W of power is output from power conditioner 10 to load 6, that is, when the output power of inverter unit 12 is 200 W, the purchased power supplied from power system 5 to load 6 is 100 W Becomes

As shown in FIG. 6, when 400 W of power is output from the power conditioner 10 to the load 6, that is, when the output power of the inverter unit 12 is 400 W, the purchased power is not supplied from the power system 5 to the load 6. 100 W of power is supplied from the power conditioner 10 to the power system 5 due to the reverse flow. Then, as shown in FIGS. 5 and 6, when the output power of the inverter unit 12 changes from 200 W to 400 W, the power supplied from the power system 5 to the load 6 changes from 100 W to “−100 W”. That is, 100 W of sold power is supplied from the power conditioner 10 to the power system 5.

Here, the output power, the purchased power, and the sold power are actually a voltage value TV detected by the voltage sensor 13 of the inverter unit 12 and a first current value TA1 detected by the first current sensor 16. Since the second current value TA2 detected by the second current sensor 8 is all sinusoidal, for example, the product of the voltage value TV and the first current value TA1 is defined as an effective value during one cycle of the voltage value TV. , And the product of the voltage value TV and the second current value TA2. Therefore, if the current phase of the second current value TA2 is inverted with respect to the voltage phase of the voltage value TV, it is determined that the power is sold, and if not, the power is purchased.

Here, the current flowing from the power system 5 to the power conditioner 10 or the load 6 is a positive signal, and the current flowing from the power conditioner 10 to the power system 5 is a negative signal. Since the mounting direction is normal, the current value (second current value TA2) supplied from the power system 5 to the load 6 decreases. For this reason, the determination unit 22 determines that the purchased power supplied from the power system 5 to the load 6 decreases. Then, the determination unit 22 becomes negative as a result of the product of the fluctuation direction (plus) of the output power of the inverter unit 12 and the fluctuation direction (minus) of the purchased power supplied from the power system 5 to the load 6. 2 It is determined that the mounting state of the current sensor 8 is normal.

On the other hand, if the mounting direction of the second current sensor 8 is reversed, the current value (second current value TA2) supplied from the power system 5 to the load 6 increases. Therefore, the determination unit 22 determines that the purchased power supplied from the power system 5 to the load 6 increases. Then, the determination unit 22 becomes positive as a result of the product of the fluctuation direction (plus) of the output power of the inverter unit 12 and the fluctuation direction (plus) of the purchased power supplied from the power system 5 to the load 6. 2 It is determined that the mounting state of the current sensor 8 is abnormal.

Further, if the second current sensor 8 is off the first electric wire 4A of the AC bus 4, the second current value TA2 detected by the second current sensor 8 becomes “0A” or a predetermined fixed value. The determination unit 22 determines that the purchased power supplied from the power system 5 to the load 6 is “0 W” or a predetermined fixed value. Then, the determining unit 22 determines that the purchased power supplied from the power system 5 to the load 6 does not fluctuate even though the output power of the inverter unit 12 fluctuates, and the second current sensor 8 It is determined that it is off.

Even when a plurality of power conditioners 10 are connected to the AC bus 4, the attachment state of the second current sensor 8 can be determined. More specifically, as shown in FIG. 7, the power management system 1 has two power conditioners 10A and 10B connected in parallel to each other. The two power conditioners 10A and 10B are connected to the AC bus 4 respectively. For example, when 400 W of power is output from the power conditioner 10A to the load 6 and no power is output from the power conditioner 10B to the load 6, reverse power flows to the power system 5 by the power from the power conditioner 10A. In this case, the power conditioner 10B determines that reverse power flows to the power system 5 even though power is not being output to the load 6, and the system interconnection relay (not shown) provided in the power conditioner 10B. Omitted) can prevent the inverter unit 12 from being disconnected from the load 6 and the power system 5.

This embodiment has the following advantages.
(1-1) The determination unit 22 attaches the second current sensor 8 based on the first current value TA1 detected by the first current sensor 16 and the second current value TA2 detected by the second current sensor 8. Determine the status. According to this configuration, it is not necessary to add a dedicated configuration for determining the mounting state of the second current sensor 8, and the second current sensor 8 attached to the first electric wire 4A connecting the power system 5 and the power conditioner 10 is unnecessary. The attachment state of the current sensor 8 can be detected.

(1-2) When the variation amount of the first current value TA1 per unit time is equal to or greater than the determination value, the determination unit 22 determines the variation amount of the second current value TA2 per unit time and the variation direction. Then, the attachment state of the second current sensor 8 is determined. According to this configuration, when the variation of the first current value TA1 per unit time is equal to or greater than the determination value, the attachment state of the second current sensor 8 is determined, so that the first current value TA1 is reduced due to noise or the like. When it changes, the attachment state of the second current sensor 8 is not determined. Therefore, erroneous determination of the mounting state of the second current sensor 8 can be suppressed.

(1-3) When the variation of the first current value TA1 per unit time is equal to or greater than the determination value, the determination unit 22 determines the second current based on the variation of the second current value TA2 per unit time. It is determined whether the sensor 8 is off the first electric wire 4A. According to this configuration, when the second current value TA2 does not fluctuate even though the first current value TA1 fluctuates, the determination unit 22 disconnects the second current sensor 8 from the first electric wire 4A. Is determined. Thus, it can be easily determined whether or not the second current sensor 8 is disengaged from the first electric wire 4A.

(1-4) The determination unit 22 determines the direction of change of the first current value TA1 and the direction of change of the second current value TA2 when the variation amount of the first current value TA1 per unit time is equal to or greater than the determination value. It is determined whether or not the mounting direction of the second current sensor 8 is correct based on. According to this configuration, the mounting direction of the second current sensor 8 can be easily determined from the fluctuation direction of the first current value TA1 per unit time and the fluctuation direction of the second current value TA2 per unit time.

(1-5) The determination unit 22 includes an A / D converter 23 and a DSP 24. According to this configuration, the output signal of the first current sensor 16 and the output signal of the second current sensor 8 are converted into the first current value TA1 and the second current value TA2, respectively, and the differential processing is performed. The determination of the mounting state of the two-current sensor 8 can be easily and promptly performed.

(1-6) The determination unit 22 outputs the mounting state of the second current sensor 8 to the notification unit 7. According to this configuration, when the attachment state of the second current sensor 8 is abnormal, the installer can be notified via the notification unit 7 that the attachment state of the second current sensor 8 is abnormal.

(2nd Embodiment)
The power conditioner 10 according to the second embodiment will be described with reference to FIGS. The power conditioner 10 of the present embodiment is different from the first embodiment in that the power conditioner 10 is applied to a single-phase three-wire power system 5. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

交流 As shown in FIG. 8, the AC bus 4 of the power management system 1 includes a first electric wire 4A, a second electric wire 4B, and a third electric wire 4C serving as a neutral electric wire. A second current sensor 9 is provided on the second electric wire 4B. The second current sensor 9 is electrically connected to the A / D converter 23 of the control device 20. The second current sensor 9 outputs a signal corresponding to the amount of current flowing through the second electric wire 4B to the A / D converter 23. The A / D converter 23 converts the output signal of the second current sensor 9 into a second current value TA3.

In the power management system 1 of the present embodiment, the first load 6A is connected to the first wire 4A and the third wire 4C, and the second load 6B is connected to the second wire 4B and the third wire 4C. Have been.
As shown in FIG. 9, the power conditioner 10 has three input / output terminals 10T connected to a first electric wire 4A, a second electric wire 4B, and a third electric wire 4C. The third wire 12X of the inverter unit 12 is connected to the first wire 4A via the input / output terminal 10T, and the fourth wire 12Y is connected to the second wire 4B via the input / output terminal 10T. The inverter unit 12 further has a fifth electric wire 12Z. The fifth electric wire 12Z is connected to the third electric wire 4C via the input / output terminal 10T. A smoothing capacitor 18A is provided between the third wire 12X and the fifth wire 12Z, and a smoothing capacitor 18B is provided between the fourth wire 12Y and the fifth wire 12Z.

The voltage sensor 13 has a first voltage sensor 13A and a second voltage sensor 13B. The first voltage sensor 13A detects a voltage between the third electric wire 12X and the fifth electric wire 12Z. The second voltage sensor 13B detects a voltage between the fourth electric wire 12Y and the fifth electric wire 12Z. The first voltage sensor 13A and the second voltage sensor 13B are electrically connected to the A / D converter 23 (see FIG. 8). The first voltage sensor 13A outputs a signal corresponding to the voltage between the third electric wire 12X and the fifth electric wire 12Z to the A / D converter 23. The second voltage sensor 13B outputs a signal corresponding to a voltage between the fourth electric wire 12Y and the fifth electric wire 12Z to the A / D converter 23. The A / D converter 23 converts the output signal of the first voltage sensor 13A into a first voltage value TV1. The A / D converter 23 converts the output signal of the second voltage sensor 13B into a second voltage value TV2. The A / D converter 23 outputs the converted values TV1 and TV2 to the DSP 24. In the present embodiment, the DSP 24 takes in the first current value TA1, the second current values TA2, TA3, the first voltage value TV1, and the second voltage value TV2, and based on these values, the second current The attachment state of the sensors 8 and 9 is determined.

The determination unit 22 in FIG. 8 determines the value obtained by adding the first voltage value TV1 detected by the first voltage sensor 13A and the second voltage value TV2 detected by the second voltage sensor 13B, and the first current sensor 16 The output power of the inverter unit 12 is calculated based on the product of the detected first current value TA1 and the product. The determining unit 22 determines whether the power system 5 has the first load 6A by the product of the voltage between the first electric wire 4A and the third electric wire 4C and the second current value TA2 detected by the second current sensor 8. Calculate the purchased power to be supplied to. The determining unit 22 determines whether the power system 5 has the second load 6B based on the product of the voltage between the second electric wire 4B and the third electric wire 4C and the second current value TA3 detected by the second current sensor 9. Calculate the purchased power to be supplied to.

(4) The determining unit 22 determines the mounting state of the second current sensor 8 and the mounting state of the second current sensor 9 respectively. FIG. 10 is a flowchart illustrating an example of a procedure of a determination process in which the determination unit 22 determines the attachment state of the second current sensor 8 and the attachment state of the second current sensor 9 respectively. The determining unit 22 starts the process when the power is supplied to the control device 20 and repeatedly executes the process at predetermined intervals until the power supply to the control device 20 is stopped.

判定 The process of determining the mounting state of the second current sensor 8 of the present embodiment is the same as the process of determining the mounting state of the second current sensor 8 of the first embodiment. That is, the processing in step S21 in FIG. 10 is the same as the processing in step S11 in FIG. 4, the processing in step S22 is the same as the processing in step S12, and the processing in step S23 is the same as the processing in step S13. The processing in step S24 is the same as the processing in step S14, the processing in step S25 is the same as the processing in step S15, and the processing in step S26 is the same as the processing in step S16. In the determination process of step S21, it is determined whether the amount of fluctuation per unit time of the purchased power supplied from the power system 5 to the first load 6A is equal to or greater than a predetermined value VX.

When the variation per unit time of the output power of the inverter unit 12 is equal to or more than the predetermined value VX (step S21: YES), the determination unit 22 purchases power supplied from the power system 5 to the second load 6B in step S31. It is determined whether or not the fluctuation amount of the power per unit time is equal to or greater than a predetermined value VX. The determining unit 22 determines the difference between the minimum value and the maximum value of the purchased power supplied from the power system 5 to the second load 6B in the unit time by the fluctuation of the purchased power supplied from the power system 5 to the second load 6B. Calculate as quantity. Here, in the process of step S31, since the voltage between the second electric wire 4B and the third electric wire 4C is constant, the variation amount of the second current value TA3 per unit time is equal to or more than the determination value. It can be said that it is a judgment.

When the fluctuation amount per unit time of the purchased power supplied from the power system 5 to the second load 6B is equal to or more than the predetermined value VX (step S31: YES), the determination unit 22 determines the output of the inverter unit 12 in step S32. It is determined whether the fluctuation direction per unit of power and the fluctuation direction per unit time of the purchased power supplied from the power system 5 to the second load 6B are the same. Here, since the output voltage of the inverter unit 12 and the voltage between the second electric wire 4B and the third electric wire 4C are respectively constant, the determination process of step S32 is performed in the unit of the first current value TA1. It can be said that the determination is made as to whether the fluctuation direction per unit time and the fluctuation direction per unit time of the second current value TA3 are the same.

The determination unit 22 determines that the direction of change per unit time of the output power of the inverter unit 12 and the direction of change per unit time of the purchased power supplied from the power system 5 to the second load 6B are the same (step S32). : YES), it is determined in step S33 that the mounting direction of the second current sensor 9 is normal, and the process is temporarily terminated. That is, when the direction of change of the first current value TA1 per unit time and the direction of change of the second current value TA3 per unit time are the same, the determination unit 22 determines that the mounting direction of the second current sensor 9 is It is determined that it is normal.

On the other hand, if the direction of change in the output power of the inverter unit 12 per unit time is opposite to the direction of the change in the power purchased from the power system 5 per unit time (step S32: NO), the determination unit 22 determines the step. In S34, it is determined that the mounting direction of the second current sensor 9 is abnormal. That is, the determination unit 22 determines that the mounting direction of the second current sensor 9 is abnormal when the direction of change of the first current value TA1 per unit time is opposite to the direction of change of the second current value TA3 per unit time. Is determined. The determination unit 22 outputs to the notification unit 7 that the mounting direction of the second current sensor 9 is abnormal in the process of step S34. In one example, the notification unit 7 displays on the display unit that the mounting direction of the second current sensor 9 is abnormal. For example, when the installer performs the power management system 1, by visually recognizing the display unit of the notification unit 7, it is possible to recognize that the mounting direction of the second current sensor 9 is abnormal.

When the fluctuation amount per unit time of the purchased power supplied from the power system 5 to the second load 6B is less than the predetermined value VX (step S31: NO), the determination unit 22 determines in step S35 that the second current sensor 9 Is deviated from the second electric wire 4B of the AC bus 4, and the process is temporarily terminated. That is, the determination unit 22 determines that the second current sensor 9 is deviated from the second electric wire 4B when the variation amount of the second current value TA3 per unit time is less than the determination value. The determination unit 22 outputs to the notification unit 7 that the second current sensor 9 is disconnected from the second electric wire 4B in the process of step S35. In one example, the notification unit 7 displays on the display unit that the second current sensor 9 is disconnected from the second electric wire 4B.

11A and 11B, an embodiment of a process for determining the attached state of the second current sensor 8 and the attached state of the second current sensor 9 will be described. FIG. 11 shows a state before the output power of the inverter unit 12 fluctuates, and FIG. 12 shows a state after the output power of the inverter unit 12 fluctuates. 11 and 12, the power consumption of the first load 6A is specified as 300W, and the power consumption of the second load 6B is specified as 50W.

As shown in FIG. 11, when 200 W of power is output from power conditioner 10 to first load 6A, that is, when the output power of inverter unit 12 is 200 W, the power supplied from power system 5 to first load 6A is purchased. Electric power becomes 100W. Since the first load 6A and the second load 6B are connected to the third electric wire 4C, electric power of 350 W is supplied. That is, 350 W of electric power is supplied to the power system 5 via the third electric wire 4C. 250 W of electric power is supplied to the second electric wire 4B. That is, 350 W of purchased power is supplied to the power system 5 via the third electric wire 4C, while 100 W of electric power is supplied to the first load 6A via the first electric wire 4A. 250 W of electric power is supplied to the second electric wire 4B.

As shown in FIG. 12, when 400 W of power is output from power conditioner 10 to first load 6A, that is, when the output power of inverter unit 12 is 400 W, the purchased power from power system 5 to first load 6A is The power is not supplied, the power flows backward, and 100 W of power is supplied from the power conditioner 10 to the power system 5. Then, as shown in FIGS. 11 and 12, when the output power of the inverter unit 12 varies from 200 W to 400 W, the power supplied from the power system 5 to the first load 6A changes from 100 W to “−100 W”. That is, 100 W of sold power is supplied from the power conditioner 10 to the power system 5.

Here, if the mounting direction of the second current sensor 8 is normal, when the output power of the inverter unit 12 increases, the current value (second current value TA2) supplied from the power system 5 to the first load 6A becomes Decrease. For this reason, the determination unit 22 determines that the purchased power supplied from the power system 5 to the first load 6A decreases. Then, the determination unit 22 becomes negative as a result of the product of the fluctuation direction (plus) of the output power of the inverter unit 12 and the fluctuation direction (minus) of the purchased power supplied from the power system 5 to the first load 6A. It is determined that the mounting state of the second current sensor 8 is normal.

On the other hand, if the mounting direction of the second current sensor 8 is reversed, when the output power of the inverter unit 12 increases, the current value (second current value TA2) supplied from the power system 5 to the first load 6A increases. I do. For this reason, the determination unit 22 determines that the purchased power supplied from the power system 5 to the first load 6A increases. Then, the determination unit 22 becomes positive as a result of the product of the fluctuation direction (plus) of the output power of the inverter unit 12 and the fluctuation direction (plus) of the purchased power supplied from the power system 5 to the first load 6A. It is determined that the mounting state of the second current sensor 8 is abnormal.

Further, if the second current sensor 8 is off the first electric wire 4A of the AC bus 4, the second current value TA2 detected by the second current sensor 8 becomes “0A” or a predetermined fixed value. The determining unit 22 determines that the purchased power supplied from the power system 5 to the first load 6A is “0 W” or a predetermined fixed value. The determination unit 22 determines that the purchased power supplied from the power system 5 to the first load 6A does not fluctuate even though the output power of the inverter unit 12 fluctuates, and the second current sensor 8 4 is determined to be out of range.

As shown in FIG. 12, when 400 W of power is output from power conditioner 10 to first load 6 </ b> A, 100 W of purchased power is supplied from power conditioner 10 to power system 5. The purchased power to be supplied to the second electric wire 4B is 450W. That is, when the output power of the inverter unit 12 increases, the purchased power supplied from the power system 5 to the second electric wire 4B increases.

Here, if the mounting direction of the second current sensor 9 is normal and the output power of the inverter unit 12 increases, the current value supplied from the power system 5 to the second electric wire 4B (second current value TA3) Increases. For this reason, the determination unit 22 determines that the purchased power supplied from the power system 5 to the second electric wire 4B increases. Then, the determination unit 22 becomes positive as a result of the product of the fluctuation direction (plus) of the output power of the inverter unit 12 and the fluctuation direction (minus) of the purchased power supplied from the power system 5 to the second electric wire 4B. Therefore, it is determined that the mounting state of the second current sensor 9 is normal.

On the other hand, if the mounting direction of the second current sensor 9 is reversed, and the output power of the inverter unit 12 increases, the current value (second current value TA3) supplied from the power system 5 to the second electric wire 4B becomes Decrease. For this reason, the determination unit 22 determines that the purchased power supplied from the power system 5 to the second electric wire 4B decreases. Then, determination unit 22 becomes negative as a result of the product of the fluctuation direction (plus) of the output power of inverter unit 12 and the fluctuation direction (minus) of the purchased power supplied from power system 5 to second electric wire 4B. Therefore, it is determined that the mounting state of the second current sensor 9 is abnormal.

If the second current sensor 9 is off the second electric wire 4B, the second current value TA3 detected by the second current sensor 9 becomes “0A” or a predetermined fixed value. It is determined that the purchased power supplied from the power system 5 to the second electric wire 4B is “0 W” or a predetermined fixed value. Then, the determining unit 22 determines that the purchased power supplied from the power system 5 to the second electric wire 4B does not change even though the output power of the inverter unit 12 changes, and the second current sensor 9 It is determined that the wire is disconnected from the second electric wire 4B.

According to the present embodiment, the following effects can be obtained.
(2-1) The judging unit 22 judges the mounting state of the second current sensor 9 based on the second current value TA3 when the variation amount of the first current value TA1 per unit time is equal to or larger than the judgment value. I do. According to this configuration, it is not necessary to add a dedicated configuration for determining the mounting state of the second current sensor 9, and the second current sensor 9 is attached to the second electric wire 4 </ b> B connecting the power system 5 and the power conditioner 10. The attachment state of the current sensor 9 can be detected.

(2-2) When the variation amount of the first current value TA1 per unit time is equal to or greater than the determination value, the determination unit 22 determines the variation amount of the second current value TA3 per unit time and the variation direction. Then, the attachment state of the second current sensor 9 is determined. According to this configuration, when the amount of change in the first current value TA1 per unit time is equal to or greater than the determination value, the attachment state of the second current sensor 9 is determined, so that the first current value TA1 is reduced due to noise or the like. When it fluctuates, the attachment state of the second current sensor 9 is not determined. Therefore, erroneous determination of the mounting state of the second current sensor 9 can be suppressed.

(2-3) When the variation amount of the first current value TA1 per unit time is equal to or greater than the determination value, the determination unit 22 determines the second current value based on the variation amount of the second current value TA3 per unit time. It is determined whether or not the sensor 9 is off the second electric wire 4B. According to this configuration, when the second current value TA3 does not fluctuate even though the first current value TA1 fluctuates, the determination unit 22 disconnects the second current sensor 9 from the second electric wire 4B. Is determined. Thus, it can be easily determined whether or not the second current sensor 9 is off the second electric wire 4B.

(2-4) The determination unit 22 determines the direction in which the first current value TA1 varies per unit time when the variation amount of the first current value TA1 per unit time is equal to or greater than the determination value, and the second current value TA3. It is determined whether the mounting direction of the second current sensor 9 is correct based on the fluctuation direction per unit time. According to this configuration, the mounting direction of the second current sensor 9 can be easily determined from the fluctuation direction of the first current value TA1 per unit time and the fluctuation direction of the second current value TA3 per unit time.

(2-5) The determination unit 22 includes an A / D converter 23 and a DSP 24. According to this configuration, the output signal of the first current sensor 16 and the output signals of the second current sensors 8 and 9 are converted into the first current value TA1 and the second current values TA2 and TA3, respectively, to perform a differentiation process. This makes it possible to easily and quickly determine each of the attachment state of the second current sensor 8 and the attachment state of the second current sensor 9.

(2-6) The determination unit 22 outputs the state of attachment of the second current sensor 9 to the notification unit 7. According to this configuration, when the mounting state of the second current sensor 9 is abnormal, the installer can be notified via the notification unit 7 that the mounting state of the second current sensor 9 is abnormal.

(Example of change)
Each of the above embodiments is an example of a form that the power conditioner according to the present disclosure can take, and is not intended to limit the form. The power conditioner according to the present disclosure may take a form different from the forms exemplified in the above embodiments. One example is a mode in which a part of the configuration of each of the above embodiments is replaced, changed, or omitted, or a mode in which a new configuration is added to each of the above embodiments. In the following modifications, the same reference numerals as those in the above-described embodiments denote the same parts as in the above-described embodiments, and a description thereof will be omitted.

In the first embodiment, the second current sensor 8 may be attached to the second electric wire 4 </ b> B of the AC bus 4. In this case, when the output power of the inverter unit 12 increases, the mounting direction of the second current sensor 8 such that the purchased power supplied from the power system 5 to the second electric wire 4B increases is made normal. Therefore, the determination unit 22 determines that the direction of change per unit time of the output power of the inverter unit 12 is the same as the direction of change per unit time of the purchased power supplied from the power system 5 to the second electric wire 4B. It is determined that the mounting direction of the second current sensor 8 is normal. Therefore, when performing the determination process of the attachment state of the second current sensor 8 in FIG. 4, the determination unit determines the determination in step S13 of the flowchart in FIG. 4 with the fluctuation direction of the output power of the inverter unit 12 per unit time. , The fluctuation direction per unit time of the purchased power supplied from the power system 5 to the second electric wire 4B is replaced with the same direction. In this case, the second electric wire 4B to which the second current sensor 8 is attached corresponds to a first electric wire.

In the second embodiment, the determination unit 22 performs the determination of the attachment state of the second current sensor 8 and the determination of the attachment state of the second current sensor 9 in parallel, but is not limited thereto. . For example, the determination unit 22 may execute one of the determination of the attachment state of the second current sensor 8 and the determination of the attachment state of the second current sensor 9 before the other.

-In 2nd Embodiment, the determination part 22 may have the 1st determination part which determines the attachment state of the 2nd current sensor 8, and the 2nd determination part which determines the attachment state of the 2nd current sensor 9. Good. The first determination unit and the second determination unit are electrically connected to the A / D converter 23 and the notification unit 7, respectively.

In the first embodiment, in the determination process of the attachment state of the second current sensor 8 in FIG. 4, the number of determinations in step S12 and step S13 may be increased. In one example, the determination unit 22 repeats the determination process of step S12 a plurality of times, and when all the determination results are the same, shifts to the next process (step S13 or step S16). The determination unit 22 repeats the determination process of step S13 a plurality of times, and when all the determination results are the same, shifts to the next process (step S14 or step S15). According to this configuration, it is possible to reduce the influence of an accidental determination result due to disturbance or the like.

In the determination process of the mounting state of the second current sensor 8 and the mounting state of the second current sensor 9 in FIG. 9 in the second embodiment, the number of determinations in step S22 and step S23 may be increased as in the above-described modification. .

In the determination process of FIG. 9 in the second embodiment, the number of determinations in steps S31 and S32 may be increased as in the above-described modification. According to this configuration, it is possible to reduce the influence of an accidental determination result due to disturbance or the like, so that it is possible to reduce the occurrence of erroneous determination of the mounting state of the second current sensor 9.

-In each embodiment, the configuration of the control device 20 can be arbitrarily changed. In one example, the control unit 21 and the determination unit 22 may be integrated.
In each embodiment, the determination unit 22 may determine the attachment state of the second current sensor 8 and the attachment state of the second current sensor 9 by analog processing instead of the DSP 24.

In each embodiment, a power generation device such as the solar power generation device 2 may be omitted from the power management system 1. In this case, the PV converter 11 is omitted from the power conditioner 10. Power conversion device 14 connected to power storage device 3 is connected to inverter unit 12 via high-voltage DC bus 15.

In each embodiment, the power storage device 3 may be omitted from the power management system 1. In this case, the power converter 14 is omitted from the power conditioner 10. In such a configuration, a power generation device such as the solar power generation device 2 corresponds to a DC power supply device, and the PV converter 11 corresponds to a converter.

In each of the embodiments, the description has been made on the assumption that the output power of the inverter unit 12 is present in order to determine the mounting state of the second current sensors 8 and 9 even during the normal operation. Only when the attachment state of the second current sensors 8 and 9 is determined, the output power of the inverter unit 12 can be realized only with the reactive power. That is, apparently, the output power from the inverter unit 12 covers the drive power of the loads 6, 6A, 6B only with the purchased power from the power system 5, and the first current value TA1 detected by the first current sensor 16 is By controlling so that the current (reactive current) is shifted by 90 ° from the phase of the voltage value TV, the second current value TA2 detected by the second current sensors 8 and 9 can be changed. The attachment state of the second current sensors 8, 9 can be determined based on the change in the second current value TA2.

The present disclosure includes a non-transitory computer-readable storage medium storing computer-executable instructions configured to implement the functions, methods, or configurations described in the above embodiments. The computer-readable storage medium may be any medium that can be accessed by one or more computer processors, such as a RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage device , And any combination thereof.

3. Power storage device (DC power supply device)
4A 1st electric wire 4B 2nd electric wire 4C 3rd electric wire 5 electric power system 8 2nd electric current sensor 9 2nd electric current sensor 10, 10A, 10B ... power conditioner 12 ... inverter part 14 ... electric power Converter (converter)
16 first current sensor 22 determination unit 23 A / D converter 24 DSP

Claims (9)

1. A power conditioner interconnected to a single-phase two-wire power system including a first electric wire and a second electric wire,
   A conversion unit that can convert the power output by the DC power supply into predetermined DC power,
   An inverter unit capable of converting the DC power into AC power and outputting the converted power;
   A first current sensor for detecting an output current of the inverter unit;
   The state of attachment of the second current sensor is determined based on a first current value detected by the first current sensor and a second current value detected by a second current sensor attached to the first electric wire. And a determining unit for performing the determination.
2. A power conditioner interconnected to a single-phase three-wire power system including a first wire, a second wire, and a third wire serving as a neutral wire,
   A conversion unit that can convert the power output by the DC power supply into predetermined DC power,
   An inverter unit capable of converting the DC power into AC power and outputting the converted power;
   A first current sensor for detecting an output current of the inverter unit;
   Based on a first current value detected by the first current sensor and a second current value detected by a second current sensor attached to each of the first electric wire and the second electric wire, (2) A power conditioner comprising: a determination unit configured to determine a mounting state of the current sensor.
3. The determination unit is configured to determine the second current value based on the amount of change in the second current value per unit time when the amount of change in the first current value per unit time is equal to or greater than a predetermined value. The power conditioner according to claim 1, wherein it is determined whether the current sensor is disconnected.
4. The determination unit is configured to determine the second current value based on a variation amount per unit time and a variation direction of the second current value when the variation amount of the first current value per unit time is equal to or greater than the predetermined value. The power conditioner according to claim 3, wherein the state of attachment of the two current sensors is determined.
5. The determination unit is configured to disconnect the second current sensor when the second current value does not fluctuate per unit time when the variation amount of the first current value per unit time is equal to or more than the predetermined value. The power conditioner according to claim 3, wherein the power conditioner is determined to be present.
6. The determination unit is configured to determine a direction in which the first current value varies per unit time when the variation amount of the first current value per unit time is equal to or greater than the predetermined value, and the unit of the second current value. 5. The power conditioner according to claim 4, wherein it is determined whether or not the mounting direction of the second current sensor is correct based on a fluctuation direction per unit time.
7. When the second current sensor is attached to the first electric wire, the determination unit is configured to output the first current value when a variation amount of the first current value per unit time is equal to or more than the predetermined value. 7. The power according to claim 6, wherein when the direction of fluctuation per unit time of the second current value is different from the direction of fluctuation of the second current value per unit time, it is determined that the mounting direction of the second current sensor is normal. Conditioner.
8. When the second current sensor is attached to the second electric wire, the determination unit is configured to output the first current value when a variation amount of the first current value per unit time is equal to or more than the predetermined value. 7. The power according to claim 6, wherein when the direction of change per unit time is the same as the direction of change of the second current value per unit time, it is determined that the mounting direction of the second current sensor is normal. Conditioner.
9. An A / D converter configured to convert output signals of the first current sensor and the second current sensor into the first current value and the second current value; The power conditioner according to any one of claims 1 to 8, further comprising: a DSP (Digital Signal Processor) for determining a mounting state of the second current sensor based on a second current value.

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