JP2015021770A

JP2015021770A - Power measurement device, power transmission system, and power measurement method

Info

Publication number: JP2015021770A
Application number: JP2013148143A
Authority: JP
Inventors: 鐘史小澤; Kanefumi Ozawa
Original assignee: NEC Platforms Ltd
Current assignee: NEC Platforms Ltd
Priority date: 2013-07-17
Filing date: 2013-07-17
Publication date: 2015-02-02
Anticipated expiration: 2033-07-17
Also published as: JP5866317B2

Abstract

PROBLEM TO BE SOLVED: To provide a power measurement device, a power transmission system, and a power measurement method.SOLUTION: In a power transmission system including first and second power generation means for supplying single-phase three-wire type AC power and a load unit including a load apparatus connected between a first voltage line and a neutral line and/or between a second voltage line and the neutral line and/or between the first voltage line and the second voltage line and supplied with the AC power from the first power generation means and/or the second power generation means, the power measurement device comprises: a power arithmetic unit for adding up and sequentially outputting, for each prescribed period and for only the prescribed period, a power value which is the product of a current value and a voltage value from each current sensor and each voltage sensor in a sensor unit; and a polarity control circuit for causing, when the result of comparison, by each polarity control circuit, of each total power value added up for only the prescribed period satisfies a prescribed condition, a value obtained by inverting a code of the total power value outputted by each power arithmetic unit to be outputted from the power arithmetic unit.

Description

本発明は、２つの発電手段から単相３線方式で供給される交流電力の電力値を測定するための電力測定装置、送電システムおよび電力測定方法に関する。 The present invention relates to a power measurement device, a power transmission system, and a power measurement method for measuring the power value of AC power supplied from two power generation means by a single-phase three-wire system.

負荷機器および自家発電装置が接続された単相３線式の商用電力系統における使用電力を電圧線毎（相毎）に計算するために、各電圧線に電流センサが取り付けられるが、各センサの取り付け方向（極性）が逆向きに取り付けられていても、各センサから出力される値を基に計算される各相毎の使用電力値および自家発電装置における発電状態に基づいて各センサの取り付け向きを判定し、その判定の結果が何れかのセンサの取り付け向きが逆であることを示していれば、計算された使用電力値の符号を反転することにより正しい電力表示を行う自家発電システムがある。 A current sensor is attached to each voltage line in order to calculate the power used for each voltage line (for each phase) in the single-phase three-wire commercial power system to which the load device and the private power generator are connected. Even if the mounting direction (polarity) is mounted in the reverse direction, the mounting direction of each sensor based on the power usage value for each phase calculated based on the value output from each sensor and the power generation state of the private power generator There is a private power generation system that displays correct power by inverting the sign of the calculated power consumption value if the result of the determination indicates that the mounting direction of any sensor is reversed .

このような自家発電システムの一例が、特許文献１に開示されている。 An example of such a private power generation system is disclosed in Patent Document 1.

図３は、特許文献１に記載されたシステムを示すブロック図である。 FIG. 3 is a block diagram showing the system described in Patent Document 1. As shown in FIG.

図３を参照すると、特許文献１に記載された電力表示システム２０は、太陽光発電装置等の発電電力を交流電力として出力する自家発電装置１と、自家発電装置１や商用電力系統３から供給される電力を交流負荷（図示せず。）に分岐断路器４を介して振り分ける分電盤２と、商用電力系統３の各電圧線に流れる電流の値を検知する電流センサＣＴ１９と、各電圧線の電圧の値を検知する電圧検出手段と、各電流センサＣＴ１９から出力される電流検出信号６および電圧検出手段から出力される電圧検出信号５を基に演算および記憶を行なう電力演算部８を含む演算記憶部７と、該演算記憶部７から出力される各種情報を表示する表示器１０とから成る。 Referring to FIG. 3, a power display system 20 described in Patent Document 1 is supplied from a private power generation apparatus 1 that outputs generated power such as a solar power generation apparatus as alternating current power, and from the private power generation apparatus 1 or the commercial power system 3. Distribution board 2 for distributing the power to the AC load (not shown) via branch disconnector 4, current sensor CT 19 for detecting the value of the current flowing through each voltage line of commercial power system 3, and each voltage A voltage detection means for detecting the voltage value of the line, and a power calculation section 8 for performing calculation and storage based on the current detection signal 6 output from each current sensor CT19 and the voltage detection signal 5 output from the voltage detection means. The calculation storage unit 7 includes a display 10 that displays various types of information output from the calculation storage unit 7.

このような構成を有する特許文献１に記載されたシステムは、自家発電装置１の発電量が所定の値以下であって、且つ、電流検出信号６および電圧検出信号５を基に電力演算部８で演算された使用電力値の絶対値が所定の値以上の場合には、電流センサＣＴ１９または電圧検出手段の取り付け向きが逆向きに取り付けられていると判断して、符号判定部１６により電力演算部８から出力された上記使用電力値の符号を反転させる。 The system described in Patent Document 1 having such a configuration is such that the power generation amount of the private power generator 1 is equal to or less than a predetermined value, and the power calculation unit 8 is based on the current detection signal 6 and the voltage detection signal 5. When the absolute value of the used power value calculated in step S is equal to or greater than a predetermined value, it is determined that the current sensor CT19 or the voltage detection means is attached in the reverse direction, and the sign determination unit 16 calculates the power. The sign of the used power value output from the unit 8 is inverted.

尚、特許文献２には、買電中か売電中かを識別し、その識別した状況を屋内で知ることができる太陽光発電システムの技術が開示されている。 Patent Document 2 discloses a technology of a solar power generation system that can identify whether power is being purchased or sold and know the identified situation indoors.

また、特許文献３には、売電電力や買電電力の電気料金の設定を、更新された料金設定値に基づいて変更可能な電力モニタ装置の技術が開示されている。 Patent Document 3 discloses a technology of a power monitoring device that can change the setting of the electricity charges for the power selling power or the power purchased based on the updated charge setting value.

また、特許文献４には、過去の電力需要量の実績データに基づいて、今後の電力需要の予測モデルを構築する技術が開示されている。 Patent Document 4 discloses a technique for constructing a prediction model for future power demand based on past data on the amount of power demand.

特開２００４−２９７９５９号公報JP 2004-297959 A 特開平１１−２２５４４０号公報Japanese Patent Laid-Open No. 11-225440 特開２００２−２９６２９９号公報JP 2002-296299 A 特開平１１−２９９０９６号公報Japanese Patent Laid-Open No. 11-299096

しかしながら、図３に示す特許文献１に記載されたシステムは、何れかの電流センサの向きが逆向きに取り付けられているか否かを判定するために、一旦、自家発電装置１の発電量を所定の値以下にしなければならない（そのためには、例えば、自家発電装置１を停止させる等の作業が必要となる）という問題点がある。 However, the system described in Patent Document 1 shown in FIG. 3 once determines the power generation amount of the private power generator 1 in order to determine whether or not any current sensor is mounted in the reverse direction. (For this purpose, for example, work such as stopping the private power generator 1 is required).

なお、特許文献２、３および４のいずれにも、各電圧線に取り付けられた電流センサの取り付け方向が逆向きに取り付けられていることを判定する技術については記載されていない。 Note that none of Patent Documents 2, 3 and 4 describes a technique for determining that the current sensor attached to each voltage line is attached in the opposite direction.

本発明の目的は、上述した問題点を解決した電力測定装置、送電システムおよび電力測定方法を提供することにある。 An object of the present invention is to provide a power measurement device, a power transmission system, and a power measurement method that solve the above-described problems.

本発明の電力測定装置は、
第１の電圧線、第２の電圧線および中性線を用いて単相３線方式で交流電力を供給する第１および第２の発電手段と、前記第１の電圧線と前記中性線との間および／または前記第２の電圧線と前記中性線との間および／または前記第１の電圧線と第２の電圧線との間に接続された負荷機器を含み、前記第１の発電手段と前記第２の発電手段との間に設けられ、前記第１の発電手段および前記第２の発電手段のうちの少なくともいずれか一方から前記交流電力が供給される負荷部とを含む送電システムにおいて、
前記第１の発電手段と前記負荷部との間の前記第１の電圧線に流れる交流電流の電流値を第１の電流値として測定する第１の電流センサと、
前記第１の電圧線と前記中性線との間の交流電圧の電圧値を第１の電圧値として測定する第１の電圧センサと、
前記第１の発電手段と前記負荷部との間の前記第２の電圧線に流れる交流電流の電流値を第２の電流値として測定する第２の電流センサと、
前記第２の電圧線と前記中性線との間の交流電圧の電圧値を第２の電圧値として測定する第２の電圧センサと、
前記第２の発電手段と前記負荷部との間の前記第１の電圧線に流れる交流電流の電流値を第３の電流値として測定する第３の電流センサと、
第１の符号反転信号を受信していない場合には、前記第１の電流値と前記第１の電圧値との積である第１の電力値を所定の期間毎に該所定の期間分だけ累計して順次出力し、一方、前記第１の符号反転信号を受信している場合には、前記第１の電力値の符号を反転した値を前記所定の期間毎に該所定の期間分だけ累計して順次出力する第１の電力演算器と、
第２の符号反転信号を受信していない場合には、前記第２の電流値と前記第２の電圧値との積である第２の電力値を前記所定の期間毎に該所定の期間分だけ累計して順次出力し、一方、前記第２の符号反転信号を受信している場合には、前記第２の電力値の符号を反転した値を前記所定の期間毎に該所定の期間分だけ累計して順次出力する第２の電力演算器と、
前記第３の電流値と前記第１の電圧値との積である第３の電力値を前記所定の期間毎に該所定の期間分だけ累計して順次出力する第３の電力演算器と、
前記第３の電流値と前記第２の電圧値との積である第４の電力値を前記所定の期間毎に該所定の期間分だけ累計して順次出力する第４の電力演算器と、
前記第１の電力演算器で前記所定の期間分だけ累計された累計電力値の絶対値が、前記第３の電力演算器で同じ前記所定の期間分だけ累計された累計電力値より大きい場合には、前記第１の符号反転信号を前記第１の電力演算器に送信する第１の極性制御回路と、
前記第２の電力演算器で前記所定の期間分だけ累計された累計電力値の絶対値が、前記第４の電力演算器で同じ前記所定の期間分だけ累計された累計電力値より大きい場合には、前記第２の符号反転信号を前記第２の電力演算器に送信する第２の極性制御回路と
を備える。 The power measuring apparatus of the present invention is
First and second power generation means for supplying AC power in a single-phase three-wire system using a first voltage line, a second voltage line, and a neutral line, the first voltage line and the neutral line And / or a load device connected between the second voltage line and the neutral line and / or between the first voltage line and the second voltage line. And a load section that is provided between the power generation means and the second power generation means and is supplied with the AC power from at least one of the first power generation means and the second power generation means. In the power transmission system,
A first current sensor that measures a current value of an alternating current flowing through the first voltage line between the first power generation means and the load unit as a first current value;
A first voltage sensor that measures a voltage value of an alternating voltage between the first voltage line and the neutral line as a first voltage value;
A second current sensor that measures a current value of an alternating current flowing through the second voltage line between the first power generation means and the load unit as a second current value;
A second voltage sensor that measures a voltage value of an AC voltage between the second voltage line and the neutral line as a second voltage value;
A third current sensor that measures a current value of an alternating current flowing through the first voltage line between the second power generation unit and the load unit as a third current value;
When the first sign inversion signal has not been received, the first power value, which is the product of the first current value and the first voltage value, is set for the predetermined period every predetermined period. If the first sign inversion signal is received, the value obtained by inverting the sign of the first power value is output for the predetermined period every predetermined period. A first power calculator that accumulates and sequentially outputs;
When the second sign inversion signal has not been received, a second power value that is a product of the second current value and the second voltage value is set for the predetermined period for each predetermined period. When the second sign inversion signal is received, the value obtained by inverting the sign of the second power value is set for the predetermined period every predetermined period. A second power calculator that accumulates and sequentially outputs only,
A third power calculator that sequentially accumulates and outputs a third power value, which is a product of the third current value and the first voltage value, for the predetermined period for each predetermined period;
A fourth power calculator that sequentially accumulates and outputs a fourth power value, which is a product of the third current value and the second voltage value, for the predetermined period for each predetermined period;
The absolute value of the accumulated power value accumulated for the predetermined period by the first power calculator is larger than the accumulated power value accumulated for the same predetermined period by the third power calculator. A first polarity control circuit for transmitting the first sign inversion signal to the first power calculator;
The absolute value of the accumulated power value accumulated for the predetermined period by the second power calculator is larger than the accumulated power value accumulated for the same predetermined period by the fourth power calculator. Comprises a second polarity control circuit for transmitting the second sign inversion signal to the second power calculator.

また、本発明の送電システムは、
第１の電圧線、第２の電圧線および中性線を用いて単相３線方式で交流電力を供給する第１および第２の発電手段と、
前記第１の電圧線と前記中性線との間、前記第２の電圧線と前記中性線との間、および、前記第１の電圧線と第２の電圧線との間に負荷機器が接続可能であって、前記第１の発電手段と前記第２の発電手段との間に設けられ、前記第１の発電手段および前記第２の発電手段のうちの少なくともいずれか一方から前記交流電力が供給される負荷部と、
前記第１の発電手段と前記負荷部との間の前記第１の電圧線に流れる交流電流の電流値を第１の電流値として測定する第１の電流センサと、
前記第１の電圧線と前記中性線との間の交流電圧の電圧値を第１の電圧値として測定する第１の電圧センサと、
前記第１の発電手段と前記負荷部との間の前記第２の電圧線に流れる交流電流の電流値を第２の電流値として測定する第２の電流センサと、
前記第２の電圧線と前記中性線との間の交流電圧の電圧値を第２の電圧値として測定する第２の電圧センサと、
前記第２の発電手段と前記負荷部との間の前記第１の電圧線に流れる交流電流の電流値を第３の電流値として測定する第３の電流センサと、
第１の符号反転信号を受信していない場合には、前記第１の電流値と前記第１の電圧値との積である第１の電力値を所定の期間毎に該所定の期間分だけ累計して順次出力し、一方、前記第１の符号反転信号を受信している場合には、前記第１の電力値の符号を反転した値を前記所定の期間毎に該所定の期間分だけ累計して順次出力する第１の電力演算器と、
第２の符号反転信号を受信していない場合には、前記第２の電流値と前記第２の電圧値との積である第２の電力値を前記所定の期間毎に該所定の期間分だけ累計して順次出力し、一方、前記第２の符号反転信号を受信している場合には、前記第２の電力値の符号を反転した値を前記所定の期間毎に該所定の期間分だけ累計して順次出力する第２の電力演算器と、
前記第３の電流値と前記第１の電圧値との積である第３の電力値を前記所定の期間毎に該所定の期間分だけ累計して順次出力する第３の電力演算器と、
前記第３の電流値と前記第２の電圧値との積である第４の電力値を前記所定の期間毎に該所定の期間分だけ累計して順次出力する第４の電力演算器と、
前記第１の電力演算器で前記所定の期間分だけ累計された累計電力値の絶対値が、前記第３の電力演算器で同じ前記所定の期間分だけ累計された累計電力値より大きい場合には、前記第１の符号反転信号を前記第１の電力演算器に送信する第１の極性制御回路と、
前記第２の電力演算器で前記所定の期間分だけ累計された累計電力値の絶対値が、前記第４の電力演算器で同じ前記所定の期間分だけ累計された累計電力値より大きい場合には、前記第２の符号反転信号を前記第２の電力演算器に送信する第２の極性制御回路と
を備える。 Moreover, the power transmission system of the present invention includes:
First and second power generation means for supplying AC power in a single-phase three-wire system using a first voltage line, a second voltage line, and a neutral line;
Load devices between the first voltage line and the neutral line, between the second voltage line and the neutral line, and between the first voltage line and the second voltage line Can be connected, and is provided between the first power generation means and the second power generation means, and the AC is supplied from at least one of the first power generation means and the second power generation means. A load section to which power is supplied;
A first current sensor that measures a current value of an alternating current flowing through the first voltage line between the first power generation means and the load unit as a first current value;
A first voltage sensor that measures a voltage value of an alternating voltage between the first voltage line and the neutral line as a first voltage value;
A second current sensor that measures a current value of an alternating current flowing through the second voltage line between the first power generation means and the load unit as a second current value;
A second voltage sensor that measures a voltage value of an AC voltage between the second voltage line and the neutral line as a second voltage value;
A third current sensor that measures a current value of an alternating current flowing through the first voltage line between the second power generation unit and the load unit as a third current value;
When the first sign inversion signal has not been received, the first power value, which is the product of the first current value and the first voltage value, is set for the predetermined period every predetermined period. If the first sign inversion signal is received, the value obtained by inverting the sign of the first power value is output for the predetermined period every predetermined period. A first power calculator that accumulates and sequentially outputs;
When the second sign inversion signal has not been received, a second power value that is a product of the second current value and the second voltage value is set for the predetermined period for each predetermined period. When the second sign inversion signal is received, the value obtained by inverting the sign of the second power value is set for the predetermined period every predetermined period. A second power calculator that accumulates and sequentially outputs only,
A third power calculator that sequentially accumulates and outputs a third power value, which is a product of the third current value and the first voltage value, for the predetermined period for each predetermined period;
A fourth power calculator that sequentially accumulates and outputs a fourth power value, which is a product of the third current value and the second voltage value, for the predetermined period for each predetermined period;
The absolute value of the accumulated power value accumulated for the predetermined period by the first power calculator is larger than the accumulated power value accumulated for the same predetermined period by the third power calculator. A first polarity control circuit for transmitting the first sign inversion signal to the first power calculator;
The absolute value of the accumulated power value accumulated for the predetermined period by the second power calculator is larger than the accumulated power value accumulated for the same predetermined period by the fourth power calculator. Comprises a second polarity control circuit for transmitting the second sign inversion signal to the second power calculator.

また、本発明の電力測定方法は、
第１の電圧線、第２の電圧線および中性線を用いて単相３線方式で交流電力を供給する第１および第２の発電手段と、前記第１の電圧線と前記中性線との間および／または前記第２の電圧線と前記中性線との間および／または前記第１の電圧線と第２の電圧線との間に接続された負荷機器を含み、前記第１の発電手段と前記第２の発電手段との間に設けられ、前記第１の発電手段および前記第２の発電手段のうちの少なくともいずれか一方から前記交流電力が供給される負荷部とを含む送電システムにおいて、
前記第１の発電手段と前記負荷部との間の前記第１の電圧線に流れる交流電流の電流値を第１の電流値として測定する第１電流測定ステップと、
前記第１の電圧線と前記中性線との間の交流電圧の電圧値を第１の電圧値として測定する第１電圧測定ステップと、
前記第１の発電手段と前記負荷部との間の前記第２の電圧線に流れる交流電流の電流値を第２の電流値として測定する第２電流測定ステップと、
前記第２の電圧線と前記中性線との間の交流電圧の電圧値を第２の電圧値として測定する第２電圧測定ステップと、
前記第２の発電手段と前記負荷部との間の前記第１の電圧線に流れる交流電流の電流値を第３の電流値として測定する第３電流測定ステップと、
第１の電力演算器が第１の符号反転信号を受信していない場合には、前記第１電流測定ステップで測定された前記第１の電流値と前記第１電圧測定ステップで測定された前記第１の電圧値との積である第１の電力値を所定の期間毎に該所定の期間分だけ累計して前記第１の電力演算器から順次出力し、一方、前記第１の符号反転信号を受信している場合には、前記第１の電力値の符号を反転した値を前記所定の期間毎に該所定の期間分だけ累計して前記第１の電力演算器から順次出力する第１電力演算ステップと、
第２電力演算器の第２の符号反転信号を受信していない場合には、前記第２電流測定ステップで測定された前記第２の電流値と前記第２電圧測定ステップで測定された前記第２の電圧値との積である第２の電力値を前記所定の期間毎に該所定の期間分だけ累計して前記第２電力演算器から順次出力し、一方、前記第２の符号反転信号を受信している場合には、前記第２の電力値の符号を反転した値を前記所定の期間毎に該所定の期間分だけ累計して前記第２電力演算器から順次出力する第２電力演算ステップと、
前記第３電流測定ステップで測定された前記第３の電流値と前記第１電圧測定ステップで測定された前記第１の電圧値との積である第３の電力値を前記所定の期間毎に該所定の期間分だけ累計して前記第３電力演算器から順次出力する第３電力演算ステップと、
前記第３電流測定ステップで測定された前記第３の電流値と前記第２電圧測定ステップで測定された前記第２の電圧値との積である第４の電力値を前記所定の期間毎に該所定の期間分だけ累計して前記第４電力演算器から順次出力する第４電力演算ステップと、
前記第１電力演算ステップにおいて前記所定の期間分だけ累計された累計電力値の絶対値が、前記第３電力演算ステップにおいて同じ前記所定の期間分だけ累計された累計電力値より大きいと判定された場合には、前記第１の符号反転信号を第１の極性制御回路から前記第１の電力演算器に送信する第１極性反転ステップと、
前記第２電力演算ステップにおいて前記所定の期間分だけ累計された累計電力値の絶対値が、前記第４電力演算ステップにおいて同じ前記所定の期間分だけ累計された累計電力値より大きいと判定された場合には、前記第２の符号反転信号を第２の極性制御回路から前記第２の電力演算器に送信する第２極性反転ステップと
を含む。 Moreover, the power measurement method of the present invention includes:
First and second power generation means for supplying AC power in a single-phase three-wire system using a first voltage line, a second voltage line, and a neutral line, the first voltage line and the neutral line And / or a load device connected between the second voltage line and the neutral line and / or between the first voltage line and the second voltage line. And a load section that is provided between the power generation means and the second power generation means and is supplied with the AC power from at least one of the first power generation means and the second power generation means. In the power transmission system,
A first current measuring step of measuring, as a first current value, a current value of an alternating current flowing through the first voltage line between the first power generation unit and the load unit;
A first voltage measuring step of measuring a voltage value of an alternating voltage between the first voltage line and the neutral line as a first voltage value;
A second current measurement step of measuring, as a second current value, a current value of an alternating current flowing through the second voltage line between the first power generation unit and the load unit;
A second voltage measuring step for measuring a voltage value of an AC voltage between the second voltage line and the neutral line as a second voltage value;
A third current measuring step for measuring a current value of an alternating current flowing through the first voltage line between the second power generation means and the load unit as a third current value;
When the first power calculator has not received the first sign inversion signal, the first current value measured in the first current measurement step and the first voltage measurement step measured in the first voltage measurement step The first power value, which is the product of the first voltage value, is accumulated for the predetermined period every predetermined period, and sequentially output from the first power calculator, while the first sign inversion When a signal is received, a value obtained by inverting the sign of the first power value is accumulated for the predetermined period for each predetermined period, and sequentially output from the first power calculator. 1 power calculation step;
When the second sign inversion signal of the second power calculator is not received, the second current value measured in the second current measurement step and the second current value measured in the second voltage measurement step The second power value, which is the product of the two voltage values, is accumulated for the predetermined period for each predetermined period and sequentially output from the second power calculator, while the second sign inversion signal When the second power value is received, the value obtained by inverting the sign of the second power value is accumulated for the predetermined period for each predetermined period, and the second power is sequentially output from the second power calculator. A calculation step;
A third power value, which is a product of the third current value measured in the third current measurement step and the first voltage value measured in the first voltage measurement step, is calculated for each predetermined period. A third power calculating step for accumulating the predetermined period and sequentially outputting from the third power calculator;
A fourth power value, which is a product of the third current value measured in the third current measurement step and the second voltage value measured in the second voltage measurement step, is calculated for each predetermined period. A fourth power calculation step of accumulating the predetermined period and sequentially outputting from the fourth power calculator;
The absolute value of the accumulated power value accumulated for the predetermined period in the first power calculating step is determined to be greater than the accumulated power value accumulated for the same predetermined period in the third power calculating step. A first polarity inversion step of transmitting the first sign inversion signal from a first polarity control circuit to the first power calculator;
The absolute value of the accumulated power value accumulated for the predetermined period in the second power calculating step is determined to be larger than the accumulated power value accumulated for the same predetermined period in the fourth power calculating step. And a second polarity inversion step of transmitting the second sign inversion signal from the second polarity control circuit to the second power calculator.

本発明には、電流センサまたは電圧センサが逆向きに取り付けられていた場合にも、いずれの発電手段も停止させずに、正しい電力値を出力することができるという効果がある。 The present invention has an effect that even when a current sensor or a voltage sensor is attached in the reverse direction, a correct power value can be output without stopping any power generation means.

本発明の実施形態を示すブロック図である。It is a block diagram which shows embodiment of this invention. 本発明の実施形態において主幹相電力値の符号を反転する所定の条件を説明する図である。It is a figure explaining the predetermined conditions which invert the code | symbol of the main phase electric power value in embodiment of this invention. 特許文献１に記載されたシステムを示すブロック図である。It is a block diagram which shows the system described in patent document 1. FIG.

次に、本発明の実施形態について図面を参照して詳細に説明する。 Next, embodiments of the present invention will be described in detail with reference to the drawings.

＜実施形態＞
図１は、本発明の実施形態を示すブロック図である。 <Embodiment>
FIG. 1 is a block diagram showing an embodiment of the present invention.

図１を参照すると、本実施形態は、第１の電圧線２８（以下、「Ｌ１線２８」とも言う。）、第２の電圧線３０（以下、「Ｌ２線３０」とも言う。）および中性線２９（以下、「Ｎ線２９」とも言う。）を使用して単相３線方式で一般家庭や企業等（以下、「需要家」とも言う。）に電力（「商用電力」とも言う。）を供給する電力会社の商用発電所２２（「第１の発電手段」とも言う。）と、需要家に設けられ、太陽光発電装置等により発電された電力を供給する自家発電装置２４（「第２の発電手段」とも言う。）と、商用発電所２２および自家発電装置２４により供給される電力を測定する電力測定部２１とから構成される。 Referring to FIG. 1, in the present embodiment, the first voltage line 28 (hereinafter also referred to as “L1 line 28”), the second voltage line 30 (hereinafter also referred to as “L2 line 30”), and the middle. Using a sex line 29 (hereinafter also referred to as “N-line 29”), it is also referred to as “commercial power” for ordinary households and businesses (hereinafter also referred to as “customers”) in a single-phase three-wire system. )) And a private power generator 24 (also referred to as “first power generation means”) and a private power generator 24 (provided by a consumer and supplying power generated by a solar power generator or the like). And a power measuring unit 21 that measures the power supplied by the commercial power plant 22 and the private power generator 24.

自家発電装置２４には、電力測定部２１を介してＬ１線２８、中性線２９、およびＬ２線３０が接続されている。 The L1 line 28, the neutral line 29, and the L2 line 30 are connected to the private power generation device 24 via the power measurement unit 21.

電力測定部２１は、負荷部７０と、センサ部８０と、演算部９０と、Ｌ１極性制御回路５２と、Ｌ２極性制御回路５３と、制御部５４とから構成される。 The power measurement unit 21 includes a load unit 70, a sensor unit 80, a calculation unit 90, an L1 polarity control circuit 52, an L2 polarity control circuit 53, and a control unit 54.

負荷部７０は、Ｌ１線２８と中性線２９との間に接続された負荷機器２５と、Ｌ２線２８とＮ線２９との間に接続された負荷機器２６と、Ｌ１線２８とＬ２線３０との間に接続された負荷機器２７とを含む。 The load unit 70 includes a load device 25 connected between the L1 line 28 and the neutral line 29, a load device 26 connected between the L2 line 28 and the N line 29, and the L1 line 28 and the L2 line. 30 and a load device 27 connected to 30.

センサ部８０は、商用発電所２２と負荷部７０とを接続するＬ１線２８を流れる交流電流の電流値（Ｉ１）を測定する電流センサ４０と、商用発電所２２と負荷部７０との間に設けられＬ１線２８とＮ線２９との間の交流電圧の電圧値（Ｖ１）を測定する電圧センサ４３と、商用発電所２２と負荷部７０とを接続するＬ２線を流れる交流電流の電流値（Ｉ２）を測定する電流センサ４１と、商用発電所２２と負荷部７０との間に設けられＬ２線３０とＮ線２９との間の交流電圧の電圧値（Ｖ２）を測定する電圧センサ４４と、自家発電装置２４と負荷部７０とを接続するＬ１線２８を流れる交流電流の電流値（ＩＰＶ）を測定する電流センサ４２とを含む。 The sensor unit 80 includes a current sensor 40 that measures the current value (I1) of the alternating current flowing through the L1 line 28 that connects the commercial power plant 22 and the load unit 70, and the commercial power plant 22 and the load unit 70. A voltage sensor 43 that measures the voltage value (V1) of the AC voltage between the L1 line 28 and the N line 29, and the current value of the AC current that flows through the L2 line that connects the commercial power plant 22 and the load unit 70. A current sensor 41 that measures (I2) and a voltage sensor 44 that is provided between the commercial power plant 22 and the load unit 70 and measures the voltage value (V2) of the AC voltage between the L2 line 30 and the N line 29. And a current sensor 42 that measures a current value (IPV) of an alternating current flowing through the L1 line 28 that connects the private power generator 24 and the load unit 70.

演算部９０は、電流センサ４０で測定された電流値と電圧センサ４３で測定された電圧値とに基づいて、商用発電所２２からＬ１線２８を介して供給される電力の値であるＬ１主幹相電力値（Ｉ１＊Ｖ１）を計算するＬ１主幹相電力演算器４８と、電流センサ４１で測定された電流値と電圧センサ４４で測定された電圧値とに基づいて、商用発電所２２からＬ２線３０を介して供給される電力の値であるＬ２主幹相電力値（Ｉ２＊Ｖ２）を計算するＬ２主幹相電力演算器５０と、電流センサ４２で測定された電流値と電圧センサ４３で測定された電圧値とに基づいて、自家発電装置２４からＬ１線２８を介して供給される電力の値であるＬ１発電相電力値（ＩＰＶ＊Ｖ１）を計算するＬ１発電相電力演算器４９と、電流センサ４２で測定された電流値と電圧センサ４４で測定された電圧値とに基づいて、自家発電装置２４からＬ２線３０を介して供給される電力の値であるＬ２発電相電力値（ＩＰＶ＊Ｖ２）を計算するＬ２発電相電力演算器５１とを含む。 The computing unit 90 is based on the current value measured by the current sensor 40 and the voltage value measured by the voltage sensor 43, and the L1 trunk that is the value of power supplied from the commercial power plant 22 via the L1 line 28. Based on the L1 main phase power calculator 48 that calculates the phase power value (I1 * V1), the current value measured by the current sensor 41, and the voltage value measured by the voltage sensor 44, L2 L2 main phase power calculator 50 for calculating the L2 main phase power value (I2 * V2), which is the value of power supplied via line 30, and the current value measured by current sensor 42 and voltage sensor 43. An L1 power generation phase power calculator 49 that calculates an L1 power generation phase power value (IPV * V1), which is a value of power supplied from the private power generation device 24 via the L1 line 28, based on the voltage value thus obtained; Measured by current sensor 42 Based on the current value and the voltage value measured by the voltage sensor 44, the L2 power generation phase power value (IPV * V2), which is the value of the power supplied from the private power generation device 24 via the L2 line 30, is calculated. Power generation phase power calculator 51.

なお、各演算器４８〜５１は、所定の周期分の累計電力値を出力する。 Each computing unit 48 to 51 outputs a cumulative power value for a predetermined period.

例えば、電圧センサ４３および電流センサ４０で測定される電圧および電流が５０Ｈｚの交流電圧および交流電流であるとすると、その周期は２０ｍｓとなり、その１周期の間の電力値の累計値が２０ｍｓの周期間隔でＬ１主幹相電力演算器４８からＬ１主幹相電力値として出力される。 For example, assuming that the voltage and current measured by the voltage sensor 43 and the current sensor 40 are an AC voltage and an AC current of 50 Hz, the cycle is 20 ms, and the cumulative value of the power value during the one cycle is a cycle of 20 ms. The L1 main phase power calculator 48 outputs the L1 main phase power value at intervals.

また、Ｌ１主幹相電力演算器４８は、Ｌ１主幹相電力値を、例えば上述した所定の周期分に対応する所定の期間毎に順次出力することが可能である。他の演算器４９〜５１についても同様である。 Further, the L1 main phase power calculator 48 can sequentially output the L1 main phase power value, for example, every predetermined period corresponding to the predetermined period described above. The same applies to the other arithmetic units 49 to 51.

Ｌ１極性制御回路５２は、Ｌ１主幹相電力演算器４８およびＬ１発電相電力演算器４９からそれぞれ信号線５８および信号線５９を介して受け取ったＬ１主幹相電力値およびＬ１発電相電力値に基づいて、第１の所定の条件（｜Ｉ１＊Ｖ１｜＞ＩＰＶ＊Ｖ１）を満たすか否かを判定し、判定結果に応じてＬ１符号反転信号を信号線５７を介してＬ１主幹相電力演算器４８に送信する。 The L1 polarity control circuit 52 is based on the L1 main phase power value and the L1 power generation phase power value received from the L1 main phase power calculator 48 and the L1 power generation phase power calculator 49 via the signal line 58 and the signal line 59, respectively. It is determined whether or not the first predetermined condition (| I1 * V1 |> IPV * V1) is satisfied, and the L1 main phase power calculator 48 transmits the L1 sign inversion signal via the signal line 57 according to the determination result. Send to.

Ｌ１主幹相電力演算器４８は、Ｌ１符号反転信号を受信している場合には、電流センサ４０で測定された電流値と電圧センサ４３で測定された電圧値とに基づいて計算される電力値の符号を反転した電力値をＬ１主幹相電力値として信号線５８に出力する。 When the L1 main phase power calculator 48 receives the L1 sign inversion signal, the power value calculated based on the current value measured by the current sensor 40 and the voltage value measured by the voltage sensor 43 Is output to the signal line 58 as the L1 main phase power value.

Ｌ２極性制御回路５３は、Ｌ２主幹相電力演算器５０およびＬ２発電相電力演算器５１からそれぞれ信号線６１および信号線６２を介して受け取ったＬ２主幹相電力値およびＬ２発電相電力値に基づいて、第２の所定の条件（｜Ｉ２＊Ｖ２｜＞ＩＰＶ＊Ｖ２）を満たすか否かを判定し、判定結果に応じてＬ２符号反転信号を信号線６０を介してＬ２主幹相電力演算器５０に送信する。 The L2 polarity control circuit 53 is based on the L2 main phase power value and the L2 power generation phase power value received from the L2 main phase power calculator 50 and the L2 power generation phase power calculator 51 via the signal line 61 and the signal line 62, respectively. , Whether or not the second predetermined condition (| I2 * V2 |> IPV * V2) is satisfied, and the L2 main phase power calculator 50 outputs the L2 sign inversion signal via the signal line 60 according to the determination result. Send to.

Ｌ２主幹相電力演算器５０は、Ｌ２符号反転信号を受信している場合には、電流センサ４１で測定された電流値と電圧センサ４４で測定された電圧値とに基づいて計算される電力値の符号を反転した電力値をＬ２主幹相電力値として信号線６１に出力する。 When the L2 main phase power calculator 50 receives the L2 sign inversion signal, the power value calculated based on the current value measured by the current sensor 41 and the voltage value measured by the voltage sensor 44 Is output to the signal line 61 as the L2 main phase power value.

制御部５４は、Ｌ１およびＬ２主幹相電力値をそれぞれ信号線５８および６１を介して所定の期間毎に順次受け取り、その受け取ったＬ１およびＬ２主幹相電力値を合計し、合計された合計電力をそれまでの積算電力に加算して新たな積算電力を求め、その求めた積算電力を使用電力量として記憶部５５に記憶させる。 The control unit 54 sequentially receives the L1 and L2 main phase power values for each predetermined period via the signal lines 58 and 61, sums up the received L1 and L2 main phase power values, and calculates the total power New accumulated power is obtained by adding to the accumulated power so far, and the obtained accumulated power is stored in the storage unit 55 as the amount of power used.

表示部５６は、記憶部５５に記憶された各種の情報や使用電力量等を表示する。 The display unit 56 displays various information, power consumption, and the like stored in the storage unit 55.

次に、符号反転の要否が上記第１および第２の所定の条件により判断できる理由について図２を用いて説明する。図２は、各主幹相電力値の符号を反転する各所定の条件を説明する図である。 Next, the reason why the necessity of code reversal can be determined based on the first and second predetermined conditions will be described with reference to FIG. FIG. 2 is a diagram illustrating each predetermined condition for inverting the sign of each main phase power value.

尚、図２では、図１の各構成要素のうちの、上記第１および第２の所定の条件についての説明に関係しない構成要素は省略されている。 In FIG. 2, components that are not related to the description of the first and second predetermined conditions among the components of FIG. 1 are omitted.

ここで、説明の便宜上、Ｌ１線２８とＮ線２９とを介して供給される電力を「Ｌ１相電力」と言い、Ｌ２線３０とＮ線２９とを介して供給される電力を「Ｌ２相電力」と言う。 Here, for convenience of explanation, the power supplied via the L1 line 28 and the N line 29 is referred to as “L1 phase power”, and the power supplied via the L2 line 30 and the N line 29 is referred to as “L2 phase power”. Say “Electricity”.

まず、Ｌ１相電力に関する上記第１の所定の条件について以下に説明する。 First, the first predetermined condition regarding the L1 phase power will be described below.

図２に示すように、Ｌ１線２８とＮ線２９との間の電圧の電圧値をＶ１、Ｌ１線２８に流れる電流の電流値をＩ１、Ｌ１線２８から負荷機器２５に流れる電流をＩＺａ、Ｌ１線２８から負荷機器２７に流れる電流をＩＺｃ、Ｌ１線２８から負荷部７０に流れる電流をＩＺ１（＝ＩＺａ＋ＩＺｃ）、自家発電装置２４からＬ１線２８（およびＬ２線３０）に流れる発電電流をＩＰＶとする。また、図２に示すＩ１の電流値を測定する電流センサ４０およびＩＰＶの電流値を測定する電流センサ４２の取り付け向き（極性）は、それぞれ矢印で示された方向に取り付けられているものとする。 As shown in FIG. 2, the voltage value of the voltage between the L1 line 28 and the N line 29 is V1, the current value of the current flowing through the L1 line 28 is I1, the current flowing from the L1 line 28 to the load device 25 is IZa, The current flowing from the L1 line 28 to the load device 27 is IZc, the current flowing from the L1 line 28 to the load unit 70 is IZ1 (= IZa + IZc), and the power generation current flowing from the private power generator 24 to the L1 line 28 (and L2 line 30) is IPV. And Also, the mounting direction (polarity) of the current sensor 40 that measures the current value of I1 and the current sensor 42 that measures the current value of IPV shown in FIG. 2 is mounted in the directions indicated by the arrows, respectively. .

まず、電流センサ４０で検出されるＬ１線２８を流れる電流Ｉ１は、
Ｉ１＝ＩＺ１−ＩＰＶ・・・・・式（１）
となる。 First, the current I1 flowing through the L1 line 28 detected by the current sensor 40 is
I1 = IZ1-IPV Expression (1)
It becomes.

よって、Ｌ１相電力の値であるＬ１主幹相電力値は、
Ｉ１＊Ｖ１＝（ＩＺ１−ＩＰＶ）＊Ｖ１＝ＩＺ１＊Ｖ１−ＩＰＶ＊Ｖ１・・・・・式（２）で表される。 Therefore, the L1 main phase power value, which is the value of the L1 phase power, is
I1 * V1 = (IZ1-IPV) * V1 = IZ1 * V1-IPV * V1 (represented by the equation (2)).

また、自家発電装置２４から商用発電所２２に向う方向の電力の逆潮流を生じさせる余剰な電力は、自家発電装置２４における発電電流（ＩＰＶ）が負荷電流（ＩＺ１）を上回った際（ＩＺ１＜ＩＰＶ）に発生するので、式（２）のＬ１主幹相電力値は、以下のように負の値をとる負電力となる。 In addition, surplus power that causes a reverse power flow in the direction from the private power generator 24 toward the commercial power plant 22 is generated when the generated current (IPV) in the private power generator 24 exceeds the load current (IZ1) (IZ1 < IPV), the L1 main phase power value in equation (2) is a negative power that takes a negative value as follows.

ＩＺ１＊Ｖ１−ＩＰＶ＊Ｖ１＜０・・・・・式（３）
また、自家発電装置２４から商用発電所２２に逆潮流し得る電流の最大値は、発電電流（ＩＰＶ）までとなるので、逆潮流によって発生し得る負電力の最大値は、自家発電装置２４における発電相電力（ＩＰＶ＊Ｖ１）までとなる。 IZ1 * V1-IPV * V1 <0 Equation (3)
Moreover, since the maximum value of the current that can be reversely flowed from the private power generator 24 to the commercial power plant 22 is the generated current (IPV), the maximum value of the negative power that can be generated by the reverse power flow is Up to generation phase power (IPV * V1).

よって、式（２）の右辺で表されるＬ１主幹相電力値（負電力）は、絶対値を用いて表すと｜ＩＺ１＊Ｖ１−ＩＰＶ＊Ｖ１｜＜ＩＰＶ＊Ｖ１となり、逆潮流する電力（左辺）が、発電電力（右辺）を上回ることはない。 Therefore, the L1 main phase power value (negative power) represented by the right side of Expression (2) is expressed as | IZ1 * V1−IPV * V1 | <IPV * V1 using an absolute value, and the power flowing backward ( The left side) does not exceed the generated power (right side).

一方で、電流センサまたは電圧センサの取り付け向きが逆であるとすると、
｜ＩＺ１＊Ｖ１−ＩＰＶ＊Ｖ１｜＞ＩＰＶ＊Ｖ１・・・・・式（４）
となり、式（４）は、逆潮流する電力が、発電電力を上回ることを表し、実際には逆潮流する電力が発電電力を上回ることはないので、電流センサまたは電圧センサの取り付け向きが逆であると判断することができる。 On the other hand, if the mounting direction of the current sensor or voltage sensor is reversed,
| IZ1 * V1-IPV * V1 |> IPV * V1 Formula (4)
Equation (4) indicates that the reverse power flow exceeds the generated power. Actually, the reverse power flow does not exceed the generated power, so the mounting direction of the current sensor or voltage sensor is reversed. It can be judged that there is.

ここで、式（１）から、Ｉ１＝ＩＺ１−ＩＰＶ、であるので、この式から電流ＩＺ１は、
ＩＺ１＝Ｉ１＋ＩＰＶ・・・・・式（５）
で表される。 Here, from the equation (1), since I1 = IZ1−IPV, the current IZ1 is
IZ1 = I1 + IPV Equation (5)
It is represented by

式（４）に、上述した式（５）を代入すると、
｜（Ｉ１＋ＩＰＶ）＊Ｖ１−ＩＰＶ＊Ｖ１｜＞ＩＰＶ＊Ｖ１
｜Ｉ１＊Ｖ１｜＞ＩＰＶ＊Ｖ１・・・・・式（６）
となる。即ち、式（６）が上記第１の所定の条件となる。 Substituting equation (5) above into equation (4),
| (I1 + IPV) * V1-IPV * V1 |> IPV * V1
| I1 * V1 |> IPV * V1 Formula (6)
It becomes. That is, Equation (6) is the first predetermined condition.

以上、Ｌ１相電力に関する上記第１の所定の条件の求め方について説明したが、Ｌ２相電力に関する上記第２の所定の条件についても同様にして求められ、
｜Ｉ２＊Ｖ２｜＞ＩＰＶ＊Ｖ２・・・・・式（７）
が上記第２の所定の条件となる。 As described above, the method for obtaining the first predetermined condition relating to the L1 phase power has been described, but the second predetermined condition relating to the L2 phase power can be obtained in the same manner.
| I2 * V2 |> IPV * V2 Formula (7)
Is the second predetermined condition.

以上、本発明には、電流センサまたは電圧センサが逆向きに取り付けられていた場合でも、自家発電装置２４を停止させずに、電流センサまたは電圧センサが逆向きに取り付けられていることを検出し、逆向きに取り付けられた電流センサまたは電圧センサに基づいて計算された主幹相電力値の符号を反転して正しい主幹相電力値を出力することができるという効果がある。 As described above, the present invention detects that the current sensor or the voltage sensor is installed in the reverse direction without stopping the private power generator 24 even when the current sensor or the voltage sensor is installed in the reverse direction. There is an effect that the correct main phase power value can be output by inverting the sign of the main phase power value calculated based on the current sensor or the voltage sensor attached in the opposite direction.

その理由は、各発電相電力値を出力するＬ１発電相電力演算器４９とＬ２発電相電力演算器５１と各極性制御回路とを設け、Ｌ１主幹相電力演算器４８およびＬ２主幹相電力演算器５０から出力される各主幹相電力値と各発電相電力値とをそれぞれ比較し、その比較結果に基づいて極性制御回路により主幹相電力値が有する符号を反転するからである。 The reason is that an L1 power generation phase power calculator 49, an L2 power generation phase power calculator 51 and each polarity control circuit for outputting each power generation phase power value are provided, and an L1 main phase power calculator 48 and an L2 main phase power calculator. This is because each main phase power value output from 50 is compared with each power generation phase power value, and the sign of the main phase power value is inverted by the polarity control circuit based on the comparison result.

１自家発電装置
２分電盤
３商用電力系統
４分岐断路器
５電圧検出信号
６電流検出信号
７演算記憶部
８電力演算部
１０表示器
１６符号判定部
１９電流センサＣＴ
２０電力表示システム
２１電力測定部
２２商用発電所
２４自家発電装置
２５負荷機器
２６負荷機器
２７負荷機器
２８第１の電圧線
２９中性線
３０第２の電圧線
４０電流センサ
４１電流センサ
４２電流センサ
４３電圧センサ
４４電圧センサ
４８Ｌ１主幹相電力演算器
４９Ｌ１発電相電力演算器
５０Ｌ２主幹相電力演算器
５１Ｌ２発電相電力演算器
５２Ｌ１極性制御回路
５３Ｌ２極性制御回路
５４制御部
５５記憶部
５６表示部
５７信号線
５８信号線
５９信号線
６０信号線
６１信号線
６２信号線
７０負荷部
８０センサ部
９０演算部 DESCRIPTION OF SYMBOLS 1 Private generator 2 Distribution board 3 Commercial power system 4 Branch disconnector 5 Voltage detection signal 6 Current detection signal 7 Calculation memory | storage part 8 Power calculation part 10 Display 16 Code | symbol determination part 19 Current sensor CT
DESCRIPTION OF SYMBOLS 20 Electric power display system 21 Electric power measurement part 22 Commercial power plant 24 Private power generation device 25 Load apparatus 26 Load apparatus 27 Load apparatus 28 First voltage line 29 Neutral line 30 Second voltage line 40 Current sensor 41 Current sensor 42 Current sensor 43 Voltage sensor 44 Voltage sensor 48 L1 main phase power calculator 49 L1 power generation phase power calculator 50 L2 main phase power calculator 51 L2 power generation phase power calculator 52 L1 polarity control circuit 53 L2 polarity control circuit 54 control unit 55 storage unit 56 display unit 57 signal line 58 signal line 59 signal line 60 signal line 61 signal line 62 signal line 70 load unit 80 sensor unit 90 calculation unit

Claims

First and second power generation means for supplying AC power in a single-phase three-wire system using a first voltage line, a second voltage line, and a neutral line, the first voltage line and the neutral line And / or a load device connected between the second voltage line and the neutral line and / or between the first voltage line and the second voltage line. And a load section that is provided between the power generation means and the second power generation means and is supplied with the AC power from at least one of the first power generation means and the second power generation means. In the power transmission system,
A first current sensor that measures a current value of an alternating current flowing through the first voltage line between the first power generation means and the load unit as a first current value;
A first voltage sensor that measures a voltage value of an alternating voltage between the first voltage line and the neutral line as a first voltage value;
A second current sensor that measures a current value of an alternating current flowing through the second voltage line between the first power generation means and the load unit as a second current value;
A second voltage sensor that measures a voltage value of an AC voltage between the second voltage line and the neutral line as a second voltage value;
A third current sensor that measures a current value of an alternating current flowing through the first voltage line between the second power generation unit and the load unit as a third current value;
When the first sign inversion signal has not been received, the first power value, which is the product of the first current value and the first voltage value, is set for the predetermined period every predetermined period. If the first sign inversion signal is received, the value obtained by inverting the sign of the first power value is output for the predetermined period every predetermined period. A first power calculator that accumulates and sequentially outputs;
When the second sign inversion signal has not been received, a second power value that is a product of the second current value and the second voltage value is set for the predetermined period for each predetermined period. When the second sign inversion signal is received, the value obtained by inverting the sign of the second power value is set for the predetermined period every predetermined period. A second power calculator that accumulates and sequentially outputs only,
A third power calculator that sequentially accumulates and outputs a third power value, which is a product of the third current value and the first voltage value, for the predetermined period for each predetermined period;
A fourth power calculator that sequentially accumulates and outputs a fourth power value, which is a product of the third current value and the second voltage value, for the predetermined period for each predetermined period;
The absolute value of the accumulated power value accumulated for the predetermined period by the first power calculator is larger than the accumulated power value accumulated for the same predetermined period by the third power calculator. A first polarity control circuit for transmitting the first sign inversion signal to the first power calculator;
The absolute value of the accumulated power value accumulated for the predetermined period by the second power calculator is larger than the accumulated power value accumulated for the same predetermined period by the fourth power calculator. Comprises a second polarity control circuit for transmitting the second sign inversion signal to the second power calculator.

First and second power generation means for supplying AC power in a single-phase three-wire system using a first voltage line, a second voltage line, and a neutral line;
Load devices between the first voltage line and the neutral line, between the second voltage line and the neutral line, and between the first voltage line and the second voltage line Can be connected, and is provided between the first power generation means and the second power generation means, and the AC is supplied from at least one of the first power generation means and the second power generation means. A load section to which power is supplied;
A first current sensor that measures a current value of an alternating current flowing through the first voltage line between the first power generation means and the load unit as a first current value;
A first voltage sensor that measures a voltage value of an alternating voltage between the first voltage line and the neutral line as a first voltage value;
A second current sensor that measures a current value of an alternating current flowing through the second voltage line between the first power generation means and the load unit as a second current value;
A second voltage sensor that measures a voltage value of an AC voltage between the second voltage line and the neutral line as a second voltage value;
A third current sensor that measures a current value of an alternating current flowing through the first voltage line between the second power generation unit and the load unit as a third current value;
When the first sign inversion signal has not been received, the first power value, which is the product of the first current value and the first voltage value, is set for the predetermined period every predetermined period. If the first sign inversion signal is received, the value obtained by inverting the sign of the first power value is output for the predetermined period every predetermined period. A first power calculator that accumulates and sequentially outputs;
When the second sign inversion signal has not been received, a second power value that is a product of the second current value and the second voltage value is set for the predetermined period for each predetermined period. When the second sign inversion signal is received, the value obtained by inverting the sign of the second power value is set for the predetermined period every predetermined period. A second power calculator that accumulates and sequentially outputs only,
A third power calculator that sequentially accumulates and outputs a third power value, which is a product of the third current value and the first voltage value, for the predetermined period for each predetermined period;
A fourth power calculator that sequentially accumulates and outputs a fourth power value, which is a product of the third current value and the second voltage value, for the predetermined period for each predetermined period;
The absolute value of the accumulated power value accumulated for the predetermined period by the first power calculator is larger than the accumulated power value accumulated for the same predetermined period by the third power calculator. A first polarity control circuit for transmitting the first sign inversion signal to the first power calculator;
The absolute value of the accumulated power value accumulated for the predetermined period by the second power calculator is larger than the accumulated power value accumulated for the same predetermined period by the fourth power calculator. Comprises a second polarity control circuit for transmitting the second sign inversion signal to the second power calculator.

The power measuring apparatus according to claim 1, wherein the predetermined period is a period corresponding to at least one cycle of the alternating current.

The power transmission system according to claim 2, wherein the predetermined period is a period of at least one cycle of the alternating current.

First and second power generation means for supplying AC power in a single-phase three-wire system using a first voltage line, a second voltage line, and a neutral line, the first voltage line and the neutral line And / or a load device connected between the second voltage line and the neutral line and / or between the first voltage line and the second voltage line. And a load section that is provided between the power generation means and the second power generation means and is supplied with the AC power from at least one of the first power generation means and the second power generation means. In the power transmission system,
A first current measuring step of measuring, as a first current value, a current value of an alternating current flowing through the first voltage line between the first power generation unit and the load unit;
A first voltage measuring step of measuring a voltage value of an alternating voltage between the first voltage line and the neutral line as a first voltage value;
A second current measurement step of measuring, as a second current value, a current value of an alternating current flowing through the second voltage line between the first power generation unit and the load unit;
A second voltage measuring step for measuring a voltage value of an AC voltage between the second voltage line and the neutral line as a second voltage value;
A third current measuring step for measuring a current value of an alternating current flowing through the first voltage line between the second power generation means and the load unit as a third current value;
When the first power calculator has not received the first sign inversion signal, the first current value measured in the first current measurement step and the first voltage measurement step measured in the first voltage measurement step The first power value, which is the product of the first voltage value, is accumulated for the predetermined period every predetermined period, and sequentially output from the first power calculator, while the first sign inversion When a signal is received, a value obtained by inverting the sign of the first power value is accumulated for the predetermined period for each predetermined period, and sequentially output from the first power calculator. 1 power calculation step;
When the second sign inversion signal of the second power calculator is not received, the second current value measured in the second current measurement step and the second current value measured in the second voltage measurement step The second power value, which is the product of the two voltage values, is accumulated for the predetermined period for each predetermined period and sequentially output from the second power calculator, while the second sign inversion signal When the second power value is received, the value obtained by inverting the sign of the second power value is accumulated for the predetermined period for each predetermined period, and the second power is sequentially output from the second power calculator. A calculation step;
A third power value, which is a product of the third current value measured in the third current measurement step and the first voltage value measured in the first voltage measurement step, is calculated for each predetermined period. A third power calculating step for accumulating the predetermined period and sequentially outputting from the third power calculator;
A fourth power value, which is a product of the third current value measured in the third current measurement step and the second voltage value measured in the second voltage measurement step, is calculated for each predetermined period. A fourth power calculation step of accumulating the predetermined period and sequentially outputting from the fourth power calculator;
The absolute value of the accumulated power value accumulated for the predetermined period in the first power calculating step is determined to be greater than the accumulated power value accumulated for the same predetermined period in the third power calculating step. A first polarity inversion step of transmitting the first sign inversion signal from a first polarity control circuit to the first power calculator;
The absolute value of the accumulated power value accumulated for the predetermined period in the second power calculating step is determined to be larger than the accumulated power value accumulated for the same predetermined period in the fourth power calculating step. A second polarity inversion step of transmitting the second sign inversion signal from the second polarity control circuit to the second power calculator.