JP7308705B2 - Power measuring device - Google Patents

Description

The present invention provides input/output power of a power supply connected via connection wiring to a single-phase three-wire power line composed of an R-phase voltage line, a T-phase voltage line, and an N-phase neutral line. relates to a power measuring device for measuring

Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2017-85796) describes that information about power is displayed using an information processing device. Specifically, the information processing device calculates the input/output power of the power supply equipment (the power generation equipment 40 and the storage battery 50) based on the detection result of the current sensor (current sensor 80), and displays it on the display screen.

JP 2017-85796 A

The information processing device described in Patent Document 1 calculates the input/output power of the power supply based on the measurement result of the input/output current of the power supply and a predetermined voltage (input/output voltage of the power supply). A program for power calculation is installed. For example, when the power supply device is connected to all of the R-phase voltage line, the T-phase voltage line, and the N-phase neutral line that constitute a single-phase three-wire power line (in the case of a 200 V output three-wire connection ), the input/output voltage of the power supply is 200V. Then, based on the measured input/output current and input/output voltage (200 V), the input/output power of the power supply device is derived.

In addition, the power supply device is an AC 100 V power supply connected to one of the R-phase voltage line and the T-phase voltage line and the N-phase neutral line, which constitute a single-phase three-wire power line. In the case of (100 V output two-line connection), the input/output power of the power supply device 7 may not be derived correctly.

For example, FIG. 4 is a diagram showing the configuration of a distributed power supply system provided with a HEMS controller 11 as a power measuring device. As shown in FIG. 4 , a single-phase three-wire power line 2 connected to a power system 1 is drawn into a distribution board 3 . The power line 2 includes an R-phase voltage line 2r, a T-phase voltage line 2t, and an N-phase neutral line 2n. In the distribution board 3, a plurality of lines are branched from the power line 2 via a plurality of branch breakers 4 (4a, 4b, 4c), to which power load devices 5 (5a, 5b) and a power supply device 7 are connected. be.

The connection wiring 6 is connected to a branch breaker 4c that is connected to three wires of an R-phase voltage line 2r, a T-phase voltage line 2t, and an N-phase neutral line 2n. The connection wiring 6 is connected to an R-phase connection wiring 6r connected to the R-phase voltage line 2r, a T-phase connection wiring 6t connected to the T-phase voltage line 2t, and an N-phase neutral line 2n. The connection wiring 6 (6r, 6t, 6n) of these three lines is connected to the connection end 8 of the power supply device 7. FIG.

The power supply device 7 has a power supply section 7 b and a power converter 7 a that connects the power supply section 7 b to the connection wiring 6 . The connection wiring 6 is composed of three wires, and these three wires are connected to the connection end 8 of the power supply device 7. It is connected to only two lines of one input/output connection wiring and the N-phase connection wiring 6n. In the example shown in FIG. 4, the power converter 7a of the power supply device 7 is connected to the R-phase connection wiring 6r and the N-phase connection wiring 6n, but is not connected to the T-phase connection wiring 6t. Therefore, no current flows through the T-phase connection wiring 6t.

An information management device such as a HEMS (Home Energy Management System) 10 is provided in the distributed power supply system when it is desired to manage and display the operating states of electrical devices connected to the distribution board 3 . For example, the HEMS controller 11 included in the HEMS 10 causes the display unit 14 to display the input/output power of the power supply device 7 and the like. Therefore, the distributed power supply system is provided with a device for measuring the input/output current of the power supply 7 and a device for measuring the input/output voltage of the power supply 7, and the measurement results thereof are transmitted to the HEMS controller 11. . In the distributed power supply system as shown in FIG. 4, the current transformer CT for measuring the current of the R-phase connection wiring 6r and the connection wiring provided with the current transformer CT (in FIG. 4, the R-phase A device (not shown) for measuring the voltage of the connection wiring 6r) is provided.

The output of the current transformer CT is input to the current measurement unit 12 of the HEMS controller 11, and the power derivation unit 13 of the HEMS controller 11 receives the output result of the current transformer CT and the separately measured voltage of the R-phase connection wiring 6r. The input/output power of the power supply device 7 is derived based on and. Specifically, the current transformer CT includes an annular magnetic core 15 surrounding the R-phase connection wiring 6r, a secondary winding 16 wound around a portion of the magnetic core 15 multiple times, and a secondary and an output line 17 connected to the winding 16 . A secondary current flows through the output line 17 connected to the secondary winding 16 in accordance with the primary current flowing through the R-phase connection wiring 6r. The output line 17 is connected to the HEMS controller 11, the current measurement unit 12 of the HEMS controller 11 can determine the current value flowing through the output line 17, and the power converter 7a of the power supply device 7 is connected based on the current value. A current value in the R-phase connection wiring 6r can be derived. Then, the power derivation unit 13 of the HEMS controller 11 derives the input/output power of the power supply device 7 based on the measurement result of the current measurement unit 12 .

When the power supply device 7 is an AC 100V power supply (100V output two-wire connection), as shown in FIG. It may be connected to two wires, or, as shown in FIG. 5, the power converter 7a of the power supply device 7 may be connected to two wires of the T-phase connection wiring 6t and the N-phase connection wiring 6n. However, in the case of the distributed power supply system shown in FIG. The T-phase connection wiring 6t to which the converter 7a is connected is not provided with the current transformer CT. As a result, in the case of the distributed power supply system shown in FIG. 5, there is a problem that the HEMS controller 11 cannot derive the input/output power of the power supply 7 correctly. Alternatively, in the case of a distributed power supply system in which the power converter 7a of the power supply device 7 is switched between the state of being connected to the R-phase connection wiring 6r and the state of being connected to the T-phase connection wiring 6t, the HEMS There is a problem that the controller 11 cannot correctly derive the input/output power of the power supply device 7 .

SUMMARY OF THE INVENTION An object of the present invention is to provide a power measuring device capable of reliably measuring the input/output power of a power supply device.

The characteristic configuration of the power measuring device according to the present invention for achieving the above object is for a single-phase three-wire power line composed of an R-phase voltage line, a T-phase voltage line, and an N-phase neutral line. A power measuring device that measures the input and output power of a power supply device connected through a connection wiring,
The connection wiring includes an R-phase connection wiring connected to the R-phase voltage line, a T-phase connection wiring connected to the T-phase voltage line, and an N-phase connection wiring connected to the N-phase neutral line. It consists of 3 lines with connection wiring,
The power supply device includes a power supply unit and a power converter that connects the power supply unit to the connection wiring, and the power converter is connected to the R-phase connection wiring and the T-phase connection wiring that constitute the connection wiring. an AC 100 V power supply connected to two wires, one of the input/output connection wiring and the N-phase connection wiring,
an annular magnetic core surrounding both the R-phase connection wiring and the T-phase connection wiring;
a secondary winding wound a plurality of times around a portion of the magnetic core;
an output line connected to the secondary winding;
The power conversion of the power supply device based on the secondary current flowing through the output line according to the primary current flowing through the R-phase connection wiring or the T-phase connection wiring to which the power converter of the power supply device is connected a current measuring unit that measures the current flowing through the input/output connection wiring to which the device is connected;
a power derivation unit that derives the input/output power of the power supply device based on the measurement result of the current measurement unit ;
One ends of the R-phase connection wiring and the T-phase connection wiring are connected to the R-phase voltage line and the T-phase voltage line, respectively, and the other end of one of the R-phase connection wiring and the T-phase connection wiring. is connected to the power converter, and the other end of the R-phase connection wiring and the T-phase connection wiring is not connected to anywhere.

According to the above characteristic configuration, both the R-phase connection wiring and the T-phase connection wiring are surrounded by the annular magnetic core. When a (primary current) is flowing, a secondary current corresponding to the primary current is input to the current measurement unit, the power converter is connected to the T-phase connection wiring, and the current (primary current) flows through the T-phase connection wiring. current) is flowing, a secondary current corresponding to the primary current is input to the current measurement unit. In other words, the current measurement unit measures the current for the R-phase connection wiring or the T-phase connection wiring regardless of whether the power converter is connected to the R-phase connection wiring or the T-phase connection wiring. The flowing current can be measured, and the power derivation unit can derive the input/output power of the power supply device based on the measurement result of the current measurement unit.
Therefore, it is possible to provide a power measuring device capable of reliably measuring the input/output power of the power supply device.

Another characteristic configuration of the power measuring device according to the present invention is the direction of the primary current when it is assumed that the primary current flows in the R-phase connection wiring in the portion surrounded by the magnetic core, and the T-phase The directions of the R-phase connection wiring and the T-phase connection wiring surrounded by the magnetic core are set so that the directions of the primary current when the primary current flows in the connection wiring are the same. at the point where

According to the above characteristic configuration, the directions of the R-phase connection wiring and the T-phase connection wiring surrounded by the magnetic core are the same as the direction of the primary current when it is assumed that the primary current flows in the R-phase connection wiring and the direction of the T-phase connection wiring. It is set so that the direction of the primary current when it is assumed that the primary current is flowing in the connection wiring is the same. That is, the sign of the input/output power derived by the power derivation unit is the same regardless of whether the power converter is connected to the R-phase connection wiring or connected to the T-phase connection wiring.

It is a figure which shows the structure of the distributed power supply system in which the power measuring apparatus is provided. It is a figure which shows the structure of the distributed power supply system in which the power measuring apparatus is provided. FIG. 10 is a diagram showing the configuration of a distributed power supply system provided with another power measuring device; FIG. 10 is a diagram showing the configuration of a distributed power supply system provided with a power measuring device of a comparative example; FIG. 10 is a diagram showing the configuration of a distributed power supply system provided with a power measuring device of a comparative example;

A power measuring device according to an embodiment of the present invention will be described below with reference to the drawings.
1 and 2 are diagrams showing the configuration of a distributed power supply system provided with a power measuring device. As shown in the figure, a single-phase three-wire power line 2 connected to a power system 1 is drawn into a distribution board 3 . The power line 2 includes an R-phase voltage line 2r, a T-phase voltage line 2t, and an N-phase neutral line 2n.

As will be described later, the power measuring device of this embodiment includes a magnetic core 15 , a secondary winding 16 , an output line 17 , a current measuring section 12 and a power lead-out section 13 .

In the distribution board 3, a plurality of lines are branched from the power line 2 via a plurality of branch breakers 4 (4a, 4b, 4c), to which power load devices 5 (5a, 5b) and a power supply device 7 are connected. be. In the example shown in FIG. 1, a power load device 5a is connected to two wires, an R-phase voltage line 2r and an N-phase neutral wire 2n, via a branch breaker 4a, and a power load device 5b is connected to the branch breaker 4b. are connected to the T-phase voltage line 2t and the N-phase neutral line 2n via the .

The connection wiring 6 is connected to a branch breaker 4c that is connected to three wires of an R-phase voltage line 2r, a T-phase voltage line 2t, and an N-phase neutral line 2n. The connection wiring 6 is connected to an R-phase connection wiring 6r connected to the R-phase voltage line 2r, a T-phase connection wiring 6t connected to the T-phase voltage line 2t, and an N-phase neutral line 2n. The connection wiring 6 (6r, 6t, 6n) of these three lines is connected to the connection end 8 of the power supply device 7. FIG.

The power supply device 7 has a power supply section 7 b and a power converter 7 a that connects the power supply section 7 b to the connection wiring 6 . The connection wiring 6 is composed of three wires, and these three wires are connected to the connection end 8 of the power supply device 7. It is connected to only two lines of one input/output connection wiring and the N-phase connection wiring 6n.

In the distributed power supply system shown in FIG. 1, the power converter 7a of the power supply device 7 is connected to two wires, the R-phase connection wiring 6r and the N-phase connection wiring 6n, but is not connected to the T-phase connection wiring 6t. not Therefore, no current flows through the T-phase connection wiring 6t.
In the distributed power supply system shown in FIG. 2, the power converter 7a of the power supply 7 is connected to two wires, the T-phase connection wiring 6t and the N-phase connection wiring 6n, but is not connected to the R-phase connection wiring 6r. not Therefore, no current flows through the R-phase connection wiring 6r.

The power supply unit 7b is configured using a power generation device, a charge/discharge device, or the like. For example, as a power generation device, various devices such as a device including a fuel cell, a device including an engine and a generator driven by the engine, and a solar power generation device can be used. As the charging/discharging device, various devices such as a storage battery (chemical battery) such as a lithium ion battery, a nickel metal hydride battery, and a lead battery, a capacitor, and a flywheel can be used.

An information management device such as a HEMS (Home Energy Management System) 10 is provided in the distributed power supply system when it is desired to manage and display the operating states of electrical devices connected to the distribution board 3 . For example, the HEMS controller 11 included in the HEMS 10 causes the display unit 14 to display the input/output power of the power supply device 7 and the like. Therefore, the distributed power supply system is provided with a device for measuring the input/output current of the power supply 7 and a device for measuring the input/output voltage of the power supply 7, and the measurement results thereof are transmitted to the HEMS controller 11. .

The output of the current transformer CT is input to the current measurement unit 12 of the HEMS controller 11, and the power derivation unit 13 of the HEMS controller 11 receives the output result of the current transformer CT and the separately measured voltage of the R-phase connection wiring 6r. The input/output power of the power supply device 7 is derived based on and.

The current transformer CT includes an annular magnetic core 15 surrounding both the R-phase connection wiring 6r and the T-phase connection wiring 6t, a secondary winding 16 wound around a portion of the magnetic core 15 multiple times, and an output line 17 connected to the secondary winding 16 . That is, both the R-phase connection wiring 6r and the T-phase connection wiring 6t are installed so as to penetrate the hollow portion of the annular magnetic core 15 in parallel. The magnetic core 15 may be made of a completely annular material, or may be made of a partially gapped annular material. For example, in the latter case, the current transformer CT can be realized using a so-called clamp-type current transformer. Although not shown, a device (not shown) for measuring the voltage of one of the R-phase connection wiring 6r and the T-phase connection wiring 6t (the voltage of the R-phase connection wiring 6r in this embodiment) is also provided. , the measurement result is transmitted to the power derivation unit 13 .

By using such a current transformer CT, the power converter 7a of the power supply device 7 is connected to the R-phase connection wiring 6r as shown in FIG. When an input/output current is flowing, a secondary current corresponding to the primary current (input/output current of the power supply device 7) flowing through the R-phase connection wiring 6r is applied to the output line 17 connected to the secondary winding 16. flow.
Alternatively, as shown in FIG. 2, when the power converter 7a of the power supply device 7 is connected to the T-phase connection wiring 6t so that the input/output current of the power supply device 7 flows through the T-phase connection wiring 6t, two A secondary current flows through the output line 17 connected to the secondary winding 16 in accordance with the primary current (input/output current of the power supply device 7) flowing through the T-phase connection wiring 6t.

The output line 17 is connected to the HEMS controller 11, and the current measurement unit 12 of the HEMS controller 11 can determine the current value flowing through the output line 17. Based on the current value, the input/output current value of the power supply device 7 can be measured. Then, the power derivation unit 13 of the HEMS controller 11 derives the input/output power of the power supply device 7 based on the measurement result of the current measurement unit 12 and the voltage of the R-phase connection wiring 6r. In other words, the power lead-out unit 13 detects the voltage of the one connection wiring 6 regardless of whether the power converter 7a is connected to the R-phase connection wiring 6r or the T-phase connection wiring 6t. (In this embodiment, the voltage of the R-phase connection wiring 6r) is used to derive the input/output power of the power supply device 7. FIG.

Specifically, in the current transformer CT of the present embodiment, in the portion surrounded by the magnetic core 15, when the primary current is flowing in the R-phase connection wiring 6r, the direction of the primary current and the direction of the primary current and the T-phase The directions of the R-phase connection wiring 6r and the T-phase connection wiring 6t surrounded by the magnetic core 15 are set so that the direction of the primary current when it is assumed that the primary current flows in the connection wiring 6t is the same. there is As a result, the power converter 7a is connected to the R-phase connection wiring 6r and a current is flowing through the R-phase connection wiring 6r, and the power converter 7a is connected to the T-phase connection wiring 6t and the T-phase connection is performed. The sign of the input/output power of the power supply device 7 derived using the voltage of the R-phase connection wiring 6r is the same regardless of whether the current is flowing through the wiring 6t.

As described above, in the power measuring device of the present embodiment, both the R-phase connection wiring 6r and the T-phase connection wiring 6t are surrounded by the annular magnetic core 15, so that the power converter 7a is connected to the R-phase connection wiring. 6r and a current (primary current) is flowing through the R-phase connection wiring 6r, a secondary current corresponding to the primary current is input to the current measuring unit 12, and the power converter 7a is connected to the T-phase. When the T-phase connection wiring 6t is connected to the connection wiring 6t and a current (primary current) is flowing through the T-phase connection wiring 6t, a secondary current corresponding to the primary current is input to the current measurement unit 12. FIG. That is, the current measurement unit 12 measures the R-phase connection wiring 6r or the T-phase connection wiring 6t regardless of whether the power converter 7a is connected to the R-phase connection wiring 6r or the T-phase connection wiring 6t. The current flowing through the T-phase connection wiring 6t can be measured, and the power derivation unit 13 can derive the input/output power of the power supply device based on the measurement result of the current measurement unit 12. FIG.

<Another embodiment>
<1>
Although the configuration of the power measuring device of the present invention and the distributed power supply system in which the device is installed has been described in the above embodiment by giving a specific example, the configuration can be changed as appropriate.

For example, FIG. 3 is a diagram showing the configuration of a distributed power supply system provided with a power measuring device according to another embodiment. In the distributed power supply system shown in FIG. 3, in the portion surrounded by the magnetic core 15 of the current transformer CT, the direction of the primary current when it is assumed that the primary current is flowing in the R-phase connection wiring 6r and the T-phase connection The directions of the R-phase connection wiring 6r and the T-phase connection wiring 6t surrounded by the magnetic core 15 are set so as to be opposite to the direction of the primary current when it is assumed that the primary current is flowing through the wiring 6t. there is

When the input/output power of the power supply device 7 is derived using the voltage of the R-phase connection wiring 6r as in the above embodiment, the current flows through the R-phase connection wiring 6r and the T-phase connection wiring 6t. The sign of the input/output power derived by the power derivation unit 13 is reversed when current is flowing. good too. In particular, when the power supply unit 7b is a power generation device, there is only a case where power is output from the power supply device 7, so only the magnitude of the input/output power derived by the power derivation unit 13, that is, the magnitude of the generated power may be displayed on the display unit 14 .

<2>
The configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments unless there is a contradiction, and the configurations disclosed in this specification The embodiments are exemplifications, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be used for a power measuring device capable of reliably measuring the input/output power of a power supply device.

2 Power line 2r R-phase voltage line 2t T-phase voltage line 2n N-phase neutral line 6 Connection wiring 6r R-phase connection wiring 6t T-phase connection wiring 6n N-phase connection wiring 7 Power supply device 7a Power converter 7b Power supply unit 12 Current measurement unit 13 Power lead-out unit 15 Magnetic core 16 Secondary winding 17 Output line

Claims (2)

Power for measuring the input/output power of a power supply connected via connection wiring to a single-phase three-wire power line consisting of an R-phase voltage line, a T-phase voltage line, and an N-phase neutral line. A measuring device,
The connection wiring includes an R-phase connection wiring connected to the R-phase voltage line, a T-phase connection wiring connected to the T-phase voltage line, and an N-phase connection wiring connected to the N-phase neutral line. It consists of 3 lines with connection wiring,
The power supply device includes a power supply unit and a power converter that connects the power supply unit to the connection wiring, and the power converter is connected to the R-phase connection wiring and the T-phase connection wiring that constitute the connection wiring. an AC 100 V power supply connected to two wires, one of the input/output connection wiring and the N-phase connection wiring,
an annular magnetic core surrounding both the R-phase connection wiring and the T-phase connection wiring;
a secondary winding wound a plurality of times around a portion of the magnetic core;
an output line connected to the secondary winding;
The power conversion of the power supply device based on the secondary current flowing through the output line according to the primary current flowing through the R-phase connection wiring or the T-phase connection wiring to which the power converter of the power supply device is connected a current measuring unit that measures the current flowing through the input/output connection wiring to which the device is connected;
a power derivation unit that derives the input/output power of the power supply device based on the measurement result of the current measurement unit ;
One ends of the R-phase connection wiring and the T-phase connection wiring are connected to the R-phase voltage line and the T-phase voltage line, respectively, and the other end of one of the R-phase connection wiring and the T-phase connection wiring. is connected to the power converter, and the other end of the R-phase connection wiring and the T-phase connection wiring is not connected anywhere. In the portion surrounded by the magnetic core, the direction of the primary current when it is assumed that the primary current is flowing through the R-phase connection wiring, and the direction of the primary current when it is assumed that the primary current is flowing through the T-phase connection wiring. 2. The power measuring device according to claim 1, wherein directions of said R-phase connection wiring and said T-phase connection wiring surrounded by said magnetic core are set so as to be the same as the direction of said primary current.

Images