JP7021748B2 - Equipment and programs - Google Patents
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- JP7021748B2 JP7021748B2 JP2019141054A JP2019141054A JP7021748B2 JP 7021748 B2 JP7021748 B2 JP 7021748B2 JP 2019141054 A JP2019141054 A JP 2019141054A JP 2019141054 A JP2019141054 A JP 2019141054A JP 7021748 B2 JP7021748 B2 JP 7021748B2
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Description
本発明は、装置及びプログラムに関する。 The present invention relates to devices and programs.
電力回路は、適切に管理を行い、事故等の防止に務める必要がある。このため、電力回路における地絡を検出、監視する装置が多々提案されており、例えば、特許文献１に記載されているような技術もある。 It is necessary to properly manage the power circuit and work to prevent accidents. For this reason, many devices for detecting and monitoring ground faults in power circuits have been proposed, and for example, there is a technique as described in Patent Document 1.
特許文献１に記載されている技術は、全漏洩電流の大きさと位相角とを測定し、前回に測定した値との差から、抵抗分漏洩電流増加量を算出し、その抵抗分漏洩電流増加量の位相角から漏洩の発生した相を特定するものである。 The technique described in Patent Document 1 measures the magnitude and phase angle of the total leakage current, calculates the amount of increase in leakage current due to resistance from the difference from the value measured last time, and increases the leakage current by resistance. The phase in which the leakage occurred is specified from the phase angle of the quantity.
しかしながら、特許文献１に記載の技術は、前回に測定した値との差から抵抗分漏洩電流増加量を算出しているため、絶縁抵抗が徐々に劣化した場合など、抵抗分漏洩電流の絶対値が大きい場合でも増加量が小さければ、検出を行うことができない。例えば、前回検出値と今回検出値の差が１ｍＡ程度あっても、異常検出値が５０ｍＡの場合、検出ができない。また、抵抗分漏洩電流増加量の位相角が漏洩の発生した相の電圧と同相とならない場合、例えば、静電容量分漏洩電流が大きく変化した場合等には、漏洩の発生した相を特定することができないものである（段落［００２４］等に記載されている）。 However, since the technique described in Patent Document 1 calculates the amount of increase in resistance leakage current from the difference from the value measured last time, the absolute value of resistance leakage current is calculated when the insulation resistance gradually deteriorates. Even if is large, if the amount of increase is small, detection cannot be performed. For example, even if the difference between the previous detection value and the current detection value is about 1 mA, if the abnormality detection value is 50 mA, detection cannot be performed. Further, when the phase angle of the increase in the leakage current due to the resistance does not become the same phase as the voltage of the phase in which the leakage has occurred, for example, when the leakage current due to the capacitance changes significantly, the phase in which the leakage has occurred is specified. It cannot be done (described in paragraph [0024] etc.).
また、特許文献１に記載の技術は、漏電箇所を探査することを目的とするものであるから、地絡が発生する前の回路の状態、つまり、絶縁が正常な状態や劣化した状態を把握することは困難なものである。 Further, since the technique described in Patent Document 1 is intended to search for an electric leakage point, it is possible to grasp the state of the circuit before the ground fault occurs, that is, the state in which the insulation is normal or deteriorated. It is difficult to do.
本発明は、かかる事情を鑑みてなされたものであり、電力回路が正常な状態、絶縁が劣化した状態、地絡が発生した状態、対地静電容量が変化した状態のいずれであっても、その状態を監視することのできる装置及びプログラムを提供することを目的とする。 The present invention has been made in view of such circumstances, regardless of whether the power circuit is in a normal state, insulation is deteriorated, a ground fault has occurred, or the capacitance to ground has changed. It is an object of the present invention to provide a device and a program capable of monitoring the state.
本発明によれば、電力回路の地絡電流を検出又は監視する装置であって、零相電流測定部と位相差特定部と初期値保持部と相特定部とを備え、前記零相電流測定部は、前記電力回路の零相電流の大きさを測定可能に構成され、前記位相差特定部は、前記電力回路の所定部分の電圧に基づいて該電圧と前記零相電流測定部が測定した零相電流との位相差を特定可能に構成され、前記初期値保持部は、前記電力回路の初期状態における零相電流を複素数で表現した値を初期零相電流値として記憶保持し、前記相特定部は、前記零相電流測定部が測定した零相電流の大きさと前記位相差特定部が特定した位相差とに基づいて前記電力回路の零相電流を複素数で表現した値と前記初期値保持部が記憶保持する初期零相電流値との差を算出し、該算出した差の偏角が前記電力回路の種別に応じて定めた複数の範囲のいずれに属するかを判定し、該判定の結果に基づいて前記電力回路の零相電流の発生相とその原因を特定可能に構成される、装置が提供される。 According to the present invention, it is a device that detects or monitors the ground fault current of the power circuit, and includes a zero-phase current measuring unit, a phase difference specifying unit, an initial value holding unit, and a phase specifying unit, and measures the zero-phase current. The unit is configured to be able to measure the magnitude of the zero-phase current of the power circuit, and the phase difference specifying unit measures the voltage and the zero-phase current measuring unit based on the voltage of a predetermined portion of the power circuit. The phase difference from the zero-phase current can be specified, and the initial value holding unit stores and holds a value expressed by a complex number of the zero-phase current in the initial state of the power circuit as the initial zero-phase current value, and holds the phase. The specific unit is a value expressed by a complex number and the initial value of the zero-phase current of the power circuit based on the magnitude of the zero-phase current measured by the zero-phase current measuring unit and the phase difference specified by the phase difference specifying unit. The difference from the initial zero-phase current value stored and retained by the holding unit is calculated, and it is determined which of the plurality of ranges determined according to the type of the power circuit the deviation angle of the calculated difference belongs to, and the determination is made. An apparatus is provided which is configured to be able to identify the generated phase of the zero-phase current of the power circuit and its cause based on the result of the above.
以下、図面を用いて本発明の実施形態について説明する。以下に示す実施形態中で示した各種特徴事項は、互いに組み合わせ可能である。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. The various features shown in the embodiments shown below can be combined with each other.
１．装置構成
まず、本発明の実施形態に係る装置について説明する。なお、ここでは、地絡電流を監視する監視装置を例として説明するが、監視装置の一部を省略することで、地絡電流を検出する検出装置とすることもできる。図１は、本発明の実施形態に係る監視装置１０の構成を示した図である。
1. 1. Device Configuration First, the device according to the embodiment of the present invention will be described. Here, a monitoring device for monitoring the ground fault current will be described as an example, but by omitting a part of the monitoring device, the detection device for detecting the ground fault current can also be used. FIG. 1 is a diagram showing a configuration of a monitoring device 10 according to an embodiment of the present invention.
同図に示すように、監視装置１０は、零相電流測定部１１、位相差特定部１２、初期値保持部１３、相特定部１４、回転処理部１５、電流解析部１６及び入出力部１７を有している。 As shown in the figure, the monitoring device 10 includes a zero-phase current measuring unit 11, a phase difference specifying unit 12, an initial value holding unit 13, a phase specifying unit 14, a rotation processing unit 15, a current analysis unit 16, and an input / output unit 17. have.
零相電流測定部１１は、電力回路の零相電流の大きさを測定可能に構成される。零相電流の測定は、例えば、電力回路の変圧器の中性点、または端子の一端のＢ種接地の接地線や、幹線ケーブルの送電部等の零相電流を測定可能な位置に零相変流器を設置し、この零相変流器を介して零相電流を測定する。 The zero-phase current measuring unit 11 is configured to be capable of measuring the magnitude of the zero-phase current of the power circuit. The zero-phase current can be measured at a position where the zero-phase current can be measured, such as the neutral point of a transformer in a power circuit, the grounding wire of class B grounding at one end of a terminal, or the transmission section of a trunk cable. A current transformer is installed and the zero-phase current is measured through this zero-phase current transformer.
位相差特定部１２は、電力回路の所定部分の電圧に基づいて該電圧と零相電流測定部１１が測定した零相電流との位相差を特定可能に構成される。例えば、位相差特定部１２は、電力回路の電圧として、変圧器の中性点と一端子の間の電圧、または端子間の電圧、または変圧器の一端子とＤ種接地、またはＣ種接地の間の電圧等のいずれかの電圧を取得する。 The phase difference specifying unit 12 is configured to be able to specify the phase difference between the voltage and the zero-phase current measured by the zero-phase current measuring unit 11 based on the voltage of a predetermined portion of the power circuit. For example, the phase difference specifying unit 12 may use the voltage between the neutral point of the transformer and one terminal, the voltage between the terminals, or one terminal of the transformer and class D ground, or class C ground as the voltage of the power circuit. Get any voltage, such as the voltage between.
初期値保持部１３は、電力回路の初期状態における零相電流を特定可能な値を初期値として記憶保持する。初期値は、例えば、電力回路、つまり、電気設備の竣工時等の設備が健全な状態で、対地静電容量を測定し、測定した対地静電容量に基づいて零相電流を算出することで得られる。また、電気設備が健全な状態において零相電流測定部１１が測定した零相電流と位相差特定部１２が特定した位相差とに基づいて算出された値を初期値として初期値保持部１３に記憶保持させるようにしてもよい。電気設備が健全な状態の値を記憶保持させることで、対地絶縁の劣化や対地静電容量の変化が徐々に進行した場合でも、漏洩電流の検出等を行うことができる。 The initial value holding unit 13 stores and holds a value that can specify the zero-phase current in the initial state of the power circuit as an initial value. The initial value is, for example, by measuring the ground capacitance in a sound state of the power circuit, that is, when the electrical equipment is completed, and calculating the zero-phase current based on the measured ground capacitance. can get. Further, the initial value holding unit 13 uses a value calculated based on the zero-phase current measured by the zero-phase current measuring unit 11 and the phase difference specified by the phase difference specifying unit 12 in a sound state of the electrical equipment as the initial value. The memory may be retained. By storing and retaining the values in a sound state of the electrical equipment, it is possible to detect the leakage current even when the deterioration of the ground insulation or the change of the ground capacitance gradually progresses.
初期値保持部１３に記憶保持させる初期値は、電力回路の初期状態における零相電流を複素数で表現した値であってもよい。複素数で表現した値とは、複素数表示やフェーザ表示とも称される表示方法であり、極形式（複素数を絶対値と偏角を用いて表わした形）を用いてもよい。 The initial value stored and stored in the initial value holding unit 13 may be a value expressed by a complex number of the zero-phase current in the initial state of the power circuit. The value expressed by a complex number is a display method also called a complex number display or a phasor display, and a polar form (a form in which a complex number is expressed by using an absolute value and an argument) may be used.
また、電力回路が高圧と、特別高圧と、超高圧とのいずれかに対応し、ケーブル又はバスダクトを含む場合には、初期値保持部１３は、ケーブル又はバスダクトの対地静電容量値または対地静電容量値に基づいて算出される零相電流を複素数で表現した値を初期値として記憶保持するようにしてもよい。 Further, when the power circuit corresponds to any of high voltage, extra high voltage, and ultra high voltage and includes a cable or a bus duct, the initial value holding unit 13 is the ground capacitance value or the ground static of the cable or the bus duct. A value expressed by a complex number of the zero-phase current calculated based on the capacitance value may be stored and held as an initial value.
同様に、電力回路が低圧であり、地中に埋設されたケーブル又は屋内に敷設されたバスダクトを含む場合には、初期値保持部１３は、ケーブル又はバスダクトの対地静電容量値または対地静電容量値に基づいて算出される零相電流を複素数で表現した値を初期値として記憶保持するようにしてもよい。 Similarly, when the power circuit is low voltage and includes a cable buried in the ground or a bus duct laid indoors, the initial value holding unit 13 is the ground capacitance value or ground capacitance of the cable or bus duct. A value expressed by a complex number of the zero-phase current calculated based on the capacitance value may be stored and held as an initial value.
ケーブル又はバスダクトの対地静電容量値は、例えば、ケーブル又はバスダクトの仕様から単位長さあたりの対地静電容量を特定し、これに線路長を乗じることで算出することができる。そして、電力回路が健全な状態では、当該回路の絶縁も良好であるため、絶縁抵抗を無限大であると想定して、零相電流を算出することができる。なお、対地静電容量値の算出に際しては、絶縁抵抗を十分大きな値、例えば、１００（ＭΩ）～１０００（ＭΩ）であるものとして取り扱う。 The ground capacitance value of the cable or bus duct can be calculated, for example, by specifying the ground capacitance per unit length from the specifications of the cable or bus duct and multiplying this by the line length. Then, when the power circuit is in a sound state, the insulation of the circuit is also good, so that the zero-phase current can be calculated assuming that the insulation resistance is infinite. In calculating the capacitance value to ground, the insulation resistance is treated as having a sufficiently large value, for example, 100 (MΩ) to 1000 (MΩ).
相特定部１４は、零相電流測定部１１が測定した零相電流の大きさと位相差特定部１２が特定した位相差とに基づいて電力回路の零相電流を複素数で表現した値と初期値保持部１３が記憶保持する初期値から特定される零相電流を複素数で表現した値との差を算出し、算出した差の偏角が電力回路の種別に応じて定めた複数の範囲のいずれに属するかを判定し、判定の結果に基づいて電力回路の零相電流の発生原因となる相を特定可能に構成される。なお、相特定部１４の具体的な動作については後述する。 The phase specifying unit 14 is a value and an initial value expressing the zero phase current of the power circuit as a complex number based on the magnitude of the zero phase current measured by the zero phase current measuring unit 11 and the phase difference specified by the phase difference specifying unit 12. The difference between the zero-phase current specified by the holding unit 13 and the value expressed by a complex number is calculated from the initial value, and the deviation angle of the calculated difference is any of a plurality of ranges determined according to the type of the power circuit. It is configured so that it can be determined whether or not it belongs to, and the phase that causes the generation of the zero-phase current of the power circuit can be specified based on the result of the determination. The specific operation of the phase specifying unit 14 will be described later.
回転処理部１５は、相特定部１４の一部であり、相特定部１４が算出した差の偏角を電力回路の種別に応じた角度だけ回転可能に構成される。例えば、低圧と、特別高圧と、超高圧とのいずれかの中性点接地の三相3線回路と、低圧の中性点接地の三相4線回路と、低圧又は高圧の非接地の三相3線回路とのいずれかである場合には、回転処理部１５は、差の偏角を１２０度回転させる処理と差の偏角を２４０度回転させる処理とを行う。また、電力回路が変圧器の低圧側が三角巻線で１相接地の三相３線回路であるとともに、変圧器の高圧側がスター型巻線である場合には、回転処理部１５は、差の偏角を－３０度または－６０度回転させる処理を行い、電力回路が変圧器の低圧側が三角巻線で１相接地の三相３線回路であるとともに、変圧器の高圧側が三角巻線である場合には、回転処理部１５は、差の偏角を－６０度または－１２０度回転させる処理を行う。これにより、相特定部１４は、回転処理部１５で回転された差の偏角に基づいて電力回路の零相電流の発生原因となる相を特定することとなる。 The rotation processing unit 15 is a part of the phase specifying unit 14, and is configured to be able to rotate the declination angle of the difference calculated by the phase specifying unit 14 by an angle corresponding to the type of the power circuit. For example, a low voltage, extra high voltage, or ultra high voltage neutral point grounded three-phase three-wire circuit, a low voltage neutral point grounded three-phase four-wire circuit, and a low-voltage or high-voltage ungrounded three-wire circuit. In the case of any of the phase 3-wire circuits, the rotation processing unit 15 performs a process of rotating the difference deviation angle by 120 degrees and a process of rotating the difference deviation angle by 240 degrees. Further, when the power circuit is a three-phase three-wire circuit in which the low-voltage side of the transformer is a triangular winding and one-phase grounded, and the high-voltage side of the transformer is a star-shaped winding, the rotation processing unit 15 makes a difference. The deviation angle is rotated by -30 degrees or -60 degrees, and the power circuit is a three-phase three-wire circuit with a triangular winding on the low-voltage side of the transformer and one-phase grounding, and a triangular winding on the high-voltage side of the transformer. In the case of a line, the rotation processing unit 15 performs a process of rotating the deviation angle of the difference by -60 degrees or −120 degrees. As a result, the phase specifying unit 14 identifies the phase that causes the generation of the zero-phase current in the power circuit based on the declination of the difference rotated by the rotation processing unit 15.
ところで、三相変圧器の星型巻線と三角巻線の電圧には３０度の位相差がある。その結果、同一相の地絡電流や、低圧側三角巻線の１相接地回路の対地静電容量による常時の地絡電流にも３０度の位相差が生じる。従って、回転処理部１５は、電力回路全体の変圧器構成による位相関係に基づく処理を行っている。 By the way, there is a phase difference of 30 degrees between the voltage of the star winding and the triangular winding of the three-phase transformer. As a result, a phase difference of 30 degrees occurs in the ground fault current of the same phase and the constant ground fault current due to the ground capacitance of the one-phase grounding circuit of the low-voltage side triangular winding. Therefore, the rotation processing unit 15 performs processing based on the phase relationship due to the transformer configuration of the entire power circuit.
電流解析部１６は、相特定部１４が算出した差を、相特定部１４が特定した相の抵抗分電流値と静電容量電流値とに分離可能に構成される。なお、電流解析部１６具体的な動作については後述する。 The current analysis unit 16 is configured to be able to separate the difference calculated by the phase identification unit 14 into the resistance component current value and the capacitance current value of the phase specified by the phase identification unit 14. The specific operation of the current analysis unit 16 will be described later.
入出力部１７は、監視装置１０のユーザインタフェイスとなるもので、操作指示の受付や、監視結果の表示等を行う。また、入出力部１７は、監視結果として相特定部１４が特定した相の全てを表示可能に構成されるとともに、相特定部１４が特定した相に別の電力回路から、その回路の対地静電容量を介して、電流が流入したことを表示可能に構成される。別の電力回路から電流が流入した場合、複数の相に逆向き（逆相）の電流が流れることから、その可能性を表示することが可能となる。 The input / output unit 17 serves as a user interface for the monitoring device 10, and receives operation instructions, displays monitoring results, and the like. Further, the input / output unit 17 is configured to be able to display all the phases specified by the phase specifying unit 14 as a monitoring result, and from another power circuit to the phase specified by the phase specifying unit 14, static electricity of the circuit. It is configured so that it can be displayed that a current has flowed through the electric capacity. When a current flows in from another power circuit, the current flows in the opposite direction (opposite phase) in a plurality of phases, so that the possibility can be displayed.
２．電力回路の概要
次に、監視装置１０を設置する電力回路の例について、その概要を説明する。図２は、電力回路の例を示した図である。
2. 2. Outline of power circuit Next, an outline of an example of a power circuit in which the monitoring device 10 is installed will be described. FIG. 2 is a diagram showing an example of a power circuit.
同図に示した例では、商用電源２０に、変圧器２１と変圧器２２と変圧器２３とが接続されている。商用電源２０は、厳密には、変圧器であり、この変圧器と、変圧器２１、変圧器２２、変圧器２３の間は、高圧、例えば、６．６ｋＶの電力回路であり、変圧器２１、変圧器２２、変圧器２３のそれぞれを介して、低圧、例えば、２１０Ｖの電力回路と接続されている。
In the example shown in the figure, the
高圧の電力回路は、一般に、非接地であるが、接地形計器用変圧器（ＥＶＴ）やコンデンサー形地絡検出装置（ＺＰＤ）を介して中性点が接地されているともいえるものである。監視装置１０は、中性点接地、非接地のいずれにも対応可能である。 The high-voltage power circuit is generally ungrounded, but it can be said that the neutral point is grounded via a grounded instrument transformer (EVT) or a capacitor-type ground fault detector (ZPD). The monitoring device 10 can handle both neutral point grounding and non-grounding.
また、変圧器２１には、負荷２４と負荷２５が接続されており、この変圧器２１と負荷２４及び負荷２５の間の回路が低圧の電力回路となる。また、変圧器２２には、負荷２６と負荷２７が接続されており、この変圧器２２と負荷２６及び負荷２７の間の回路が低圧の電力回路となる。同様に、変圧器２３には、負荷２８と負荷２９が接続されており、この変圧器２３と負荷２８及び負荷２９の間の回路が低圧の電力回路となる。監視装置１０は、これらの低圧の電力回路にも対応可能である。なお、変圧器２１は、Ｙ（星型）－△（三角）巻線の変圧器であり、変圧器２２は、△－△巻線の変圧器、変圧器２３は、△－Ｙ巻線の変圧器であるものとする。
Further, the load 24 and the load 25 are connected to the
３．三相４線回路等
次に、電力回路が低圧、特別高圧、超高圧のいずれかの中性点接地の三相3線回路、低圧の中性点接地の三相4線回路、低圧又は高圧の非接地の三相3線回路の場合の監視装置１０の動作について説明する。なお、ここでは、三相４線回路を例として説明する。図３は、三相４線回路の等価回路を示した図である。なお、同図に示した等価回路は、図２に示した変圧器２３の二次側回路に相当する。
3. 3. Three-phase four-wire circuit, etc. Next, the power circuit is a low-voltage, extra-high-voltage, or ultra-high-voltage neutral-point grounded three-phase three-wire circuit, low-voltage neutral-point grounded three-phase four-wire circuit, low-voltage or high-voltage. The operation of the monitoring device 10 in the case of the ungrounded three-phase three-wire circuit will be described. Here, a three-phase four-wire circuit will be described as an example. FIG. 3 is a diagram showing an equivalent circuit of a three-phase four-wire circuit. The equivalent circuit shown in FIG. 2 corresponds to the secondary circuit of the
同図に示した等価回路では、ＥＲ、ＥＳ、ＥＴは、それぞれ、Ｒ相の電源、Ｓ相の電源、Ｔ相の電源を表し、ＲＲ、ＲＳ、ＲＴ、ＲＮは、それぞれ、Ｒ相の絶縁抵抗、Ｓ相の絶縁抵抗、Ｔ相の絶縁抵抗、Ｎ相（中性相）の絶縁抵抗を表し、ＣＲ、ＣＳ、ＣＴ、ＣＮは、それぞれ、Ｒ相の対地静電容量、Ｓ相の対地静電容量、Ｔ相の対地静電容量、Ｎ相の対地静電容量を表している。また、ＲＢは、Ｂ種接地抵抗、ＲＣは、Ｃ種接地抵抗を表している。なお、電力回路は、配線の距離が長く、分布定数回路として扱うことが適切であるが、ここでは、説明の簡易化のために、集中定数回路としている。 In the equivalent circuit shown in the figure, ER, ES, and ET represent R-phase power supply, S-phase power supply, and T-phase power supply, respectively, and RR, RS, RT, and RN represent R-phase insulation, respectively. Represents resistance, S-phase insulation resistance, T-phase insulation resistance, and N-phase (neutral phase) insulation resistance, where CR, CS, CT, and CN represent the R-phase ground capacitance and S-phase ground, respectively. It represents the capacitance, the T-phase ground capacitance, and the N-phase ground capacitance. Further, RB represents a class B ground resistance, and RC represents a class C ground resistance. It should be noted that the power circuit has a long wiring distance, and it is appropriate to treat it as a distributed constant circuit, but here, for the sake of simplification of the explanation, it is a lumped constant circuit.
図３に示した等価回路に監視装置１０を設置する場合、零相電流測定部１１は、Ｂ種接地抵抗ＲＢを流れる電流を測定する。位相差特定部１２は、Ｒ相の電圧ＥＲを取得する。電圧ＥＲは、変圧器の中性点と一端子間の電圧、または端子間の電圧、または変圧器の一端子とＤ種接地、またはＣ種接地間の電圧等のいずれかで測定可能である。 When the monitoring device 10 is installed in the equivalent circuit shown in FIG. 3, the zero-phase current measuring unit 11 measures the current flowing through the class B grounding resistance RB. The phase difference specifying unit 12 acquires the R-phase voltage ER. The voltage ER can be measured by either the neutral point of the transformer and the voltage between one terminal, the voltage between the terminals, or the voltage between one terminal of the transformer and the D-class ground, or the C-class ground, and the like. ..
初期値保持部１３に記憶保持する初期零相電流値は、電力回路が健全な状態、つまり、図３に示した等価回路では、各相の絶縁抵抗、ＲＲ、ＲＳ、ＲＴ、ＲＮの値が十分に大きい場合の値である。なお、図３に示した等価回路が理想的なものであれば、各相の対地静電容量、ＣＲ、ＣＳ、ＣＴ、ＣＮの値が等しく、零相電流は流れないが、実際には、ＣＲ、ＣＳ、ＣＴ、ＣＮの値は等しくないため、零相電流が流れることになる。 The initial zero-phase current value stored and stored in the initial value holding unit 13 is a state in which the power circuit is in a sound state, that is, in the equivalent circuit shown in FIG. 3, the values of the insulation resistance, RR, RS, RT, and RN of each phase are set. This is the value when it is large enough. If the equivalent circuit shown in FIG. 3 is ideal, the values of the capacitance to ground, CR, CS, CT, and CN of each phase are the same, and the zero-phase current does not flow, but in reality, Since the values of CR, CS, CT, and CN are not equal, a zero-phase current will flow.
初期値保持部１３に記憶保持する初期零相電流値は、例えば、図４にＩＲＢ０で示すようになる。図４は、初期零相電流値を複素平面上に表した図である。初期零相電流値ＩＲＢ０は、その偏角がθである。なお、図４は、Ｒ相の電圧を基準としているため、Ｒ相の電圧の偏角は、０度となる。 The initial zero-phase current value stored and stored in the initial value holding unit 13 is shown by IRB0 in FIG. 4, for example. FIG. 4 is a diagram showing the initial zero-phase current value on the complex plane. The declination angle of the initial zero-phase current value IRB0 is θ. Since FIG. 4 is based on the R-phase voltage, the declination of the R-phase voltage is 0 degrees.
続いて、電力回路で絶縁の劣化や地絡の発生、対地静電容量の変化等によって、零相電流が変化した場合を説明する。零相電流は、零相電流測定部１１と位相差特定部１２により、複素数による表現が可能となるが、これを複素平面上に表すと、図５に示すようになる。図５は、零相電流を複素平面上に表した例を示した図である。 Next, a case where the zero-phase current changes due to deterioration of insulation, occurrence of ground fault, change in capacitance to ground, etc. in the power circuit will be described. The zero-phase current can be expressed by a complex number by the zero-phase current measuring unit 11 and the phase difference specifying unit 12, and this can be expressed on a complex plane as shown in FIG. FIG. 5 is a diagram showing an example in which the zero-phase current is represented on a complex plane.
例えば、電力回路のＲ相の絶縁が劣化した場合やＲ相に地絡が発生した場合には、図５に示す零相電流ＩＲＢ１が流れることになる。Ｔ相の絶縁が劣化した場合やＴ相に地絡が発生した場合には、図５に示す零相電流ＩＲＢ２が流れることになる。Ｓ相の絶縁が劣化した場合やＳ相に地絡が発生した場合には、図５に示す零相電流ＩＲＢ３が流れることになる。また、Ｒ相の対地静電容量が大きくなった場合には、図５に示す零相電流ＩＲＢ４が流れ、Ｓ相の絶縁の劣化と対地静電容量の増大が同時に生じた場合には、図５に示す零相電流ＩＲＢ５が流れることになる。なお、当然のことであるが、零相電流ＩＲＢ１、零相電流ＩＲＢ２、零相電流ＩＲＢ３、零相電流ＩＲＢ４及び零相電流ＩＲＢ５は、同時に流れることはない。 For example, when the insulation of the R phase of the power circuit deteriorates or when a ground fault occurs in the R phase, the zero-phase current IRB1 shown in FIG. 5 flows. When the insulation of the T phase deteriorates or when a ground fault occurs in the T phase, the zero-phase current IRB2 shown in FIG. 5 flows. When the insulation of the S phase deteriorates or when a ground fault occurs in the S phase, the zero-phase current IRB3 shown in FIG. 5 flows. Further, when the ground capacitance of the R phase becomes large, the zero-phase current IRB4 shown in FIG. 5 flows, and when the deterioration of the insulation of the S phase and the increase of the ground capacitance occur at the same time, FIG. The zero-phase current IRB5 shown in 5 will flow. As a matter of course, the zero-phase current IRB1, the zero-phase current IRB2, the zero-phase current IRB3, the zero-phase current IRB4, and the zero-phase current IRB5 do not flow at the same time.
この図５に示した零相電流ＩＲＢ１、零相電流ＩＲＢ２、零相電流ＩＲＢ３、零相電流ＩＲＢ４及び零相電流ＩＲＢ５は、初期零相電流値ＩＲＢ０を含むものである。したがって、零相電流と初期零相電流値ＩＲＢ０の差が電力回路で絶縁の劣化や地絡の発生、対地静電容量の変化等によって生じた電流となる。 The zero-phase current IRB1, the zero-phase current IRB2, the zero-phase current IRB3, the zero-phase current IRB4, and the zero-phase current IRB5 shown in FIG. 5 include the initial zero-phase current value IRB0. Therefore, the difference between the zero-phase current and the initial zero-phase current value IRB0 is the current generated by deterioration of insulation, occurrence of ground fault, change in capacitance to ground, etc. in the power circuit.
そこで、相特定部１４は、まず、零相電流と初期零相電流値ＩＲＢ０の差を算出する。この算出結果を複素平面上に表すと、図６に示すようになる。図６は、零相電流と初期零相電流値ＩＲＢ０の差を複素平面上で表したものである。 Therefore, the phase specifying unit 14 first calculates the difference between the zero-phase current and the initial zero-phase current value IRB0. The calculation result is shown in FIG. 6 on a complex plane. FIG. 6 shows the difference between the zero-phase current and the initial zero-phase current value IRB0 on the complex plane.
零相電流ＩＲＢ１と初期零相電流値ＩＲＢ０の差、つまり、ＩＲＢ１－ＩＲＢ０は、電流ＩＲ１となる。同様に、零相電流ＩＲＢ２と初期零相電流値ＩＲＢ０の差（ＩＲＢ２－ＩＲＢ０）は、電流ＩＲ２、零相電流ＩＲＢ３と初期零相電流値ＩＲＢ０の差（ＩＲＢ３－ＩＲＢ０）は、電流ＩＲ３、零相電流ＩＲＢ４と初期零相電流値ＩＲＢ０の差（ＩＲＢ４－ＩＲＢ０）は、電流ＩＲ４、零相電流ＩＲＢ５と初期零相電流値ＩＲＢ０の差（ＩＲＢ５－ＩＲＢ０）は、電流ＩＲ５となる。 The difference between the zero-phase current IRB1 and the initial zero-phase current value IRB0, that is, IRB1-IRB0 is the current IR1. Similarly, the difference between the zero-phase current IRB2 and the initial zero-phase current value IRB0 (IRB2-IRB0) is the current IR2, and the difference between the zero-phase current IRB3 and the initial zero-phase current value IRB0 (IRB3-IRB0) is the current IR3, zero. The difference between the phase current IRB4 and the initial zero-phase current value IRB0 (IRB4-IRB0) is the current IR4, and the difference between the zero-phase current IRB5 and the initial zero-phase current value IRB0 (IRB5-IRB0) is the current IR5.
続いて、相特定部１４は、算出した零相電流と初期零相電流値ＩＲＢ０の差を１２０度及び２４０度回転する。図７は、図６に示した電流ＩＲ１～電流ＩＲ５を１２０度回転した複素平面を示した図である。また、図８は、図６に示した電流ＩＲ１～電流ＩＲ５を２４０度回転した複素平面を示した図である。 Subsequently, the phase specifying unit 14 rotates the difference between the calculated zero-phase current and the initial zero-phase current value IRB0 by 120 degrees and 240 degrees. FIG. 7 is a diagram showing a complex plane obtained by rotating the currents IR1 to IR5 shown in FIG. 6 by 120 degrees. Further, FIG. 8 is a diagram showing a complex plane obtained by rotating the currents IR1 to IR5 shown in FIG. 6 by 240 degrees.
図６に示した電流ＩＲ１、電流ＩＲ２、電流ＩＲ３、電流ＩＲ４、電流ＩＲ５を１２０度回転すると、図７に示すようになる。この場合には、複素平面の実軸は、Ｓ相の電圧と一致する。 When the current IR1, the current IR2, the current IR3, the current IR4, and the current IR5 shown in FIG. 6 are rotated by 120 degrees, the results are shown in FIG. In this case, the real axis of the complex plane coincides with the voltage of the S phase.
また、図６に示した電流ＩＲ１、電流ＩＲ２、電流ＩＲ３、電流ＩＲ４、電流ＩＲ５を２４０度回転すると、図８に示すようになる。この場合には、複素平面の実軸は、Ｔ相の電圧と一致する。 Further, when the current IR1, the current IR2, the current IR3, the current IR4, and the current IR5 shown in FIG. 6 are rotated by 240 degrees, the results are shown in FIG. In this case, the real axis of the complex plane coincides with the voltage of the T phase.
次に、相特定部１４が、零相電流が変化した原因となる相を特定する。相の特定は、回転処理を施していない電流と、１２０度の回転処理を施した電流と、２４０度の回転処理を施した電流のうち、偏角が－３０度よりも大きく９０度以下である電流に基づいて行う。 Next, the phase specifying unit 14 identifies the phase that causes the change in the zero-phase current. The phase is specified when the declination angle is larger than -30 degrees and 90 degrees or less among the current not subjected to the rotation treatment, the current subjected to the rotation treatment of 120 degrees, and the current subjected to the rotation treatment of 240 degrees. It is based on a certain current.
ここで、－３０度よりも大きく９０度以下となる範囲について説明する。図９は、偏角の範囲を説明するための図である。 Here, a range larger than -30 degrees and 90 degrees or less will be described. FIG. 9 is a diagram for explaining the range of the declination.
同図に示すように、電流に対して回転処理を施していない場合、基準となる偏角が０度の軸は、Ｒ相の実軸に相当する軸となる。また、偏角が９０度となる軸は、Ｒ相の虚軸に相当し、偏角が－３０度となる軸は、Ｓ相の虚軸に相当する。したがって、電流の偏角が－３０度よりも大きく９０度よりも小さい場合は、この電流に少なくともＲ相の抵抗分電流が含まれていることとなり、電流の偏角が９０度の場合は、この電流はＲ相の静電容量分電流であることとなる。つまり、電流に回転処理を施していない場合に、当該電流の偏角が－３０度よりも大きく９０度以下であれば、少なくともＲ相に変化が生じてことが判明する。 As shown in the figure, when the rotation process is not applied to the current, the axis having the reference declination angle of 0 degrees is the axis corresponding to the actual axis of the R phase. The axis having a declination of 90 degrees corresponds to the imaginary axis of the R phase, and the axis having the declination of −30 degrees corresponds to the imaginary axis of the S phase. Therefore, if the deviation angle of the current is larger than -30 degrees and smaller than 90 degrees, it means that this current includes at least the resistance component current of the R phase, and if the deviation angle of the current is 90 degrees, This current is the current corresponding to the capacitance of the R phase. That is, when the current is not subjected to the rotation processing, if the declination angle of the current is larger than -30 degrees and 90 degrees or less, it is found that at least the R phase is changed.
また、電流に対して１２０度の回転処理を施している場合、基準となる偏角が０度の軸は、Ｓ相の実軸に相当する軸となる。また、偏角が９０度となる軸は、Ｓ相の虚軸に相当し、偏角が－３０度となる軸は、Ｔ相の虚軸に相当する。したがって、電流の偏角が－３０度よりも大きく９０度よりも小さい場合は、この電流に少なくともＳ相の抵抗分電流が含まれていることとなり、電流の偏角が９０度の場合は、この電流はＳ相の静電容量分電流であることとなる。つまり、電流に１２０度の回転処理を施した場合に、当該電流の偏角が－３０度よりも大きく９０度以下であれば、少なくともＳ相に変化が生じてことが判明する。 Further, when the rotation process of 120 degrees is applied to the current, the axis having the reference declination angle of 0 degrees is the axis corresponding to the actual axis of the S phase. The axis having a declination of 90 degrees corresponds to the imaginary axis of the S phase, and the axis having the declination of −30 degrees corresponds to the imaginary axis of the T phase. Therefore, if the deviation angle of the current is larger than -30 degrees and smaller than 90 degrees, it means that this current includes at least the resistance component current of the S phase, and if the deviation angle of the current is 90 degrees, This current is the current corresponding to the capacitance of the S phase. That is, when the current is subjected to a rotation process of 120 degrees, if the declination angle of the current is larger than −30 degrees and 90 degrees or less, it is found that at least the S phase is changed.
同様に、電流に対して２４０度の回転処理を施している場合、基準となる偏角が０度の軸は、Ｔ相の実軸に相当する軸となる。また、偏角が９０度となる軸は、Ｔ相の虚軸に相当し、偏角が－３０度となる軸は、Ｒ相の虚軸に相当する。したがって、電流の偏角が－３０度よりも大きく９０度よりも小さい場合は、この電流に少なくともＴ相の抵抗分電流が含まれていることとなり、電流の偏角が９０度の場合は、この電流はＴ相の静電容量分電流であることとなる。つまり、電流に２４０度の回転処理を施した場合に、当該電流の偏角が－３０度よりも大きく９０度以下であれば、少なくともＴ相に変化が生じてことが判明する。 Similarly, when the rotation process of 240 degrees is applied to the current, the axis having the reference declination angle of 0 degrees is the axis corresponding to the actual axis of the T phase. The axis having a declination of 90 degrees corresponds to the imaginary axis of the T phase, and the axis having the declination of −30 degrees corresponds to the imaginary axis of the R phase. Therefore, if the deviation angle of the current is larger than -30 degrees and smaller than 90 degrees, it means that this current includes at least the resistance component current of the T phase, and if the deviation angle of the current is 90 degrees, This current is the current corresponding to the capacitance of the T phase. That is, when the current is subjected to a rotation process of 240 degrees, if the declination angle of the current is larger than −30 degrees and 90 degrees or less, it is found that at least the T phase is changed.
したがって、前述の電流ＩＲ１は、回転処理を施していない状態で偏角が０度なので、Ｒ相の電流と判断される。同様に、電流ＩＲ２は、２４０度の回転処理を施した状態で偏角が０度なのでＴ相の電流と判断され、電流ＩＲ３は、１２０度の回転処理を施した状態で偏角が０度なのでＳの相の電流と判断される。また、電流ＩＲ４は、回転処理を施していない状態で偏角が９０度なので、Ｒ相の電流と判断され、電流ＩＲ５は、１２０度の回転処理を施した状態で偏角が３０度なのでＳの相の電流と判断される。 Therefore, the above-mentioned current IR1 is determined to be an R-phase current because the declination angle is 0 degrees in the state where the rotation processing is not performed. Similarly, the current IR2 is judged to be a T-phase current because the declination is 0 degrees in the state of being rotated by 240 degrees, and the current IR3 is judged to be the current of the T phase, and the declination of the current IR3 is 0 degrees in the state of being rotated by 120 degrees. Therefore, it is judged to be the current of the S phase. Further, the current IR4 is determined to be an R-phase current because the declination angle is 90 degrees in the state where the rotation process is not performed, and the current IR5 is S because the declination angle is 30 degrees in the state where the rotation process is performed at 120 degrees. It is judged to be the current of the phase.
次に、電流解析部１６が零相電流と初期零相電流値ＩＲＢ０の差の解析を行う。この解析では、差の電流の偏角が０度の場合は、Ｒ相の抵抗分電流（回転処理なしの場合）、Ｓ相の抵抗分電流（１２０度回転の場合）、Ｔ相の抵抗分電流（２４０度回転の場合）と判断する。また、差の電流の偏角が９０度の場合は、Ｒ相の静電容量分電流（回転処理なしの場合）、Ｓ相の静電容量分電流（１２０度回転の場合）、Ｔ相の静電容量分電流（２４０度回転の場合）と判断する。 Next, the current analysis unit 16 analyzes the difference between the zero-phase current and the initial zero-phase current value IRB0. In this analysis, when the deviation angle of the difference current is 0 degrees, the resistance component current of the R phase (when no rotation processing is performed), the resistance component current of the S phase (when rotating 120 degrees), and the resistance component of the T phase. Judged as current (in the case of 240 degree rotation). When the deviation angle of the difference current is 90 degrees, the R phase capacitance current (without rotation processing), the S phase capacitance current (120 degree rotation), and the T phase It is determined that the current is the capacitance component (in the case of 240 degree rotation).
差の電流の偏角が０度よりも大きく９０度よりも小さい場合には、Ｒ相の抵抗分電流と静電容量分電流の合成（回転処理なしの場合）、Ｓ相の抵抗分電流と静電容量分電流の合成（１２０度回転の場合）、Ｔ相の抵抗分電流と静電容量分電流の合成（２４０度回転の場合）と判断し、これらを分離する。 When the deviation angle of the difference current is larger than 0 degrees and smaller than 90 degrees, the combination of the resistance component current of the R phase and the capacitance component current (without rotation processing), and the resistance component current of the S phase It is determined that the capacitance component current is combined (in the case of 120-degree rotation) and the T-phase resistance component current and the capacitance component current are combined (in the case of 240-degree rotation), and these are separated.
また、差の電流の偏角が－３０度よりも大きく０度よりも小さい場合には、Ｒ相の抵抗分電流とＳ相の静電容量分電流の合成（回転処理なしの場合）、Ｓ相の抵抗分電流とＴ相の静電容量分電流の合成（１２０度回転の場合）、Ｔ相の抵抗分電流とＲ相の静電容量分電流の合成（２４０度回転の場合）と判断し、これらを分離する。 When the deviation angle of the difference current is larger than -30 degrees and smaller than 0 degrees, the combination of the resistance component current of the R phase and the capacitance component current of the S phase (when no rotation processing is performed), S. Judgment is the combination of the resistance component current of the phase and the capacitance component current of the T phase (in the case of 120 degree rotation), and the combination of the resistance component current of the T phase and the capacitance component current of the R phase (in the case of 240 degree rotation). And separate these.
抵抗分電流と静電容量分電流の分離は、複素数の演算により行う。なお、複素数の演算に代えて複素ベクトルを用いたベクトル演算により抵抗分電流と静電容量分電流の分離を行うようにしてもよい。 Separation of resistance current and capacitance current is performed by complex number calculation. Instead of the complex number calculation, the resistance component current and the capacitance component current may be separated by a vector operation using a complex vector.
ところで、図６乃至図８に示した電流の複素平面での表示は説明のために用いたものであるが、これらを入出力部１７に画面表示するようにしてもよい。電力回路等の電気設備の管理は、通常、電気主任技術者等の技術者が行うため、複素平面での表示は、これら技術者が直感的に電力回路の状態を把握する一助となる。 By the way, the display of the currents shown in FIGS. 6 to 8 on the complex plane is used for explanation, but these may be displayed on the screen in the input / output unit 17. Since the management of electrical equipment such as electric power circuits is usually performed by engineers such as chief electrical engineers, the display on the complex plane helps these engineers to intuitively grasp the state of the electric power circuit.
４．三相３線回路
次に、電力回路が変圧器の低圧側が三角巻線で１相接地の三相３線回路の場合の監視装置１０の動作について説明する。図１０は、三相３線回路の等価回路を示した図である。なお、同図に示した等価回路は、図２に示した変圧器２１の二次側回路または変圧器２２の二次側回路に相当する。
4. Three-phase three-wire circuit Next, the operation of the monitoring device 10 will be described when the power circuit is a three-phase three-wire circuit in which the low-voltage side of the transformer is a triangular winding and one-phase grounded. FIG. 10 is a diagram showing an equivalent circuit of a three-phase three-wire circuit. The equivalent circuit shown in FIG. 2 corresponds to the secondary circuit of the
同図に示した等価回路では、ＥＲＳ、ＥＳＴ、ＥＴＲは、それぞれ、Ｒ相－Ｓ相間の電源、Ｓ相－Ｔ相間の電源、Ｔ相－Ｒ相間の電源を表し、ＲＲ、ＲＳ、ＲＴは、それぞれ、Ｒ相の絶縁抵抗、Ｓ相の絶縁抵抗、Ｔ相の絶縁抵抗を表し、ＣＲ、ＣＳ、ＣＴは、それぞれ、Ｒ相の対地静電容量、Ｓ相の対地静電容量、Ｔ相の対地静電容量を表している。また、ＲＢは、Ｂ種接地抵抗、ＲＤは、Ｄ種接地抵抗を表している。なお、電力回路は、配線の距離が長く、分布定数回路として扱うことが適切であるが、ここでは、説明の簡易化のために、集中定数回路としている。 In the equivalent circuit shown in the figure, ERS, EST, and ETR represent the power supply between the R phase and the S phase, the power supply between the S phase and the T phase, and the power supply between the T phase and the R phase, respectively. Represents the insulation resistance of the R phase, the insulation resistance of the S phase, and the insulation resistance of the T phase, respectively. CR, CS, and CT represent the capacitance to ground of the R phase, the capacitance to ground of the S phase, and T, respectively. It represents the phase capacitance to ground. Further, RB represents a class B ground resistance, and RD represents a class D ground resistance. It should be noted that the power circuit has a long wiring distance, and it is appropriate to treat it as a distributed constant circuit, but here, for the sake of simplification of the explanation, it is a lumped constant circuit.
図１０に示した等価回路に監視装置１０を設置する場合、零相電流測定部１１は、Ｂ種接地抵抗ＲＢを流れる電流を測定する。なお、零相電流測定部１１は、幹線ケーブルの送電部から零相電流を取得してもよいが、その場合は、図１０中のＴとＲＴの間のケーブルと、ＲとＲＲの間のケーブルと、ＳとＲＳの間のケーブルとのそれぞれを流れる電流の合計の電流を取得する。また、位相差特定部１２は、前述したのと同様に、変圧器２３の二次側回路のＲ相の電圧ＥＲを取得する。
When the monitoring device 10 is installed in the equivalent circuit shown in FIG. 10, the zero-phase current measuring unit 11 measures the current flowing through the class B grounding resistance RB. The zero-phase current measuring unit 11 may acquire the zero-phase current from the power transmission unit of the trunk cable, but in that case, the cable between T and RT in FIG. 10 and between R and RR. Obtain the total current of the currents flowing through each of the cable and the cable between S and RS. Further, the phase difference specifying unit 12 acquires the voltage ER of the R phase of the secondary circuit of the
図２に示した等価回路の商用電源２０、及びＥＢ（Ｂ種接地）は変圧器２１、変圧器２２、変圧器２３に対して共通なので、商用電源２０の星型巻線（変圧器２１の一次側巻線と同じ）のＲ相電圧位相（変圧器２３の二次側巻線のＲ相電圧位相と同じ）を基準とする。 その結果、変圧器２１の二次回路のＳ相－Ｒ相間の電圧位相は基準より３０度進んでおり、変圧器２２の二次回路のＳ相－Ｒ相間の電圧位相は基準より６０度進んでいる。
Since the
したがって、監視装置１０は、まず、回転処理部１５が各電流の回転処理を行う。回転処理部１５は、対象となる回路が変圧器２２の二次側回路であれば、－３０度の回転処理を行い、対象となる変圧器２３の二次側回路であれば、－６０度の回転処理を行う。
Therefore, in the monitoring device 10, first, the rotation processing unit 15 performs rotation processing of each current. If the target circuit is the secondary side circuit of the
図１１は、回転処理部１５による回転処理後の位相を示した図である。回転処理部１５による回転処理の結果、Ｓ相－Ｒ相間の電圧の位相、つまり、Ｒ相の抵抗成分電流に対応するＲ相実軸が０度となる。したがって、Ｒ相の静電容量分に対応するＲ相虚軸が９０度となり、Ｔ相の抵抗成分電流に対応するＴ相実軸が６０度となり、Ｔ相の静電容量分に対応するＴ相虚軸が１５０度となる。 FIG. 11 is a diagram showing the phase after the rotation processing by the rotation processing unit 15. As a result of the rotation processing by the rotation processing unit 15, the phase of the voltage between the S phase and the R phase, that is, the R phase real axis corresponding to the resistance component current of the R phase becomes 0 degrees. Therefore, the R-phase imaginary axis corresponding to the capacitance of the R-phase is 90 degrees, the real axis of the T-phase corresponding to the resistance component current of the T-phase is 60 degrees, and the T corresponding to the capacitance of the T-phase is T. The phase imaginary axis is 150 degrees.
続いて、初期零相電流と零相電流について説明する。図１２は、初期零相電流と零相電流を複素平面上に示した図である。 Next, the initial zero-phase current and the zero-phase current will be described. FIG. 12 is a diagram showing the initial zero-phase current and the zero-phase current on the complex plane.
初期値保持部１３に記憶保持する初期零相電流値は、電力回路が健全な状態、つまり、図１０に示した等価回路では、各相の絶縁抵抗、ＲＲ、ＲＳ、ＲＴの値が十分に大きい場合の値であり、Ｓ相をＢ種接地しているため、Ｒ相の対地静電容量ＣＲとＴ相の対地静電容量ＣＴを合成した対地静電容量に起因して流れる電流となる。このため、初期値保持部１３に記憶保持している初期零相電流値ＩＲＢ０の偏角は、Ｒ相虚軸とＴ相虚軸の間、つまり、９０度以上１５０度以下となる。 The initial zero-phase current value stored and stored in the initial value holding unit 13 is in a state where the power circuit is sound, that is, in the equivalent circuit shown in FIG. 10, the insulation resistance, RR, RS, and RT values of each phase are sufficiently sufficient. This is a value when the value is large, and since the S phase is grounded to class B, the current flows due to the ground capacitance obtained by combining the ground capacitance CR of the R phase and the ground capacitance CT of the T phase. .. Therefore, the declination of the initial zero-phase current value IRB0 stored and stored in the initial value holding unit 13 is between the R-phase imaginary axis and the T-phase imaginary axis, that is, 90 degrees or more and 150 degrees or less.
零相電流が変化した場合、例えば、図１２に示すような零相電流ＩＲＢ１１が測定された場合、相特定部１４は、零相電流ＩＲＢ１１と初期零相電流値ＩＲＢ０の差である電流ＩＲ１１を算出する。 When the zero-phase current changes, for example, when the zero-phase current IRB11 as shown in FIG. 12 is measured, the phase identification unit 14 determines the current IR11 which is the difference between the zero-phase current IRB11 and the initial zero-phase current value IRB0. calculate.
次に、相特定部１４による回路に変化が生じた相の特定について説明する。相特定部１４は、零相電流ＩＲＢ１１と初期零相電流値ＩＲＢ０の差の電流である電流ＩＲ１１の偏角が、予め定めたいずれの領域に含まれるかによって、回路に変化が生じた相の特定を行う。図１３は、偏角の領域を示した図である。 Next, the phase identification unit 14 will explain the identification of the phase in which the circuit has changed. The phase specifying unit 14 is a phase in which the circuit has changed depending on which region contains the declination of the current IR11, which is the current of the difference between the zero-phase current IRB11 and the initial zero-phase current value IRB0. Make a specific. FIG. 13 is a diagram showing a region of declination.
図１３に示すように、偏角の領域は、領域Ａから領域Ｆまでの６領域がある。領域Ａは、偏角が－９０度（２７０度）よりも大きく０度以下の領域である。領域Ａのうち、偏角が０度の部分は、Ｒ相実軸と一致する。 As shown in FIG. 13, there are six declination regions from region A to region F. The region A is a region having a declination angle of more than −90 degrees (270 degrees) and 0 degrees or less. The portion of the region A whose declination angle is 0 degrees coincides with the real axis of the R phase.
また、領域Ｂは、偏角が０度よりも大きく６０度以下の領域である。領域Ｂのうち、偏角が６０度の部分は、Ｔ相実軸と一致する。 Further, the region B is a region where the declination angle is larger than 0 degrees and 60 degrees or less. The portion of the region B having an argument of 60 degrees coincides with the T-phase real axis.
領域Ｃは、偏角が６０度よりも大きく９０度以下の領域である。領域Ｃのうち、偏角が９０度の部分は、Ｒ相虚軸と一致する。 The region C is a region having a declination angle of more than 60 degrees and 90 degrees or less. The portion of the region C whose declination angle is 90 degrees coincides with the R-phase imaginary axis.
領域Ｄは、偏角が９０度よりも大きく、初期値保持部１３に保持している初期零相電流値ＩＲＢ０の偏角以下の領域である。 The region D is a region in which the declination angle is larger than 90 degrees and is equal to or less than the declination angle of the initial zero-phase current value IRB0 held in the initial value holding unit 13.
領域Ｅは、偏角が初期値保持部１３に保持している初期零相電流値ＩＲＢ０の偏角よりも大きく、１５０度以下の領域である。領域Ｅのうち、偏角が１５０度の部分は、Ｔ相虚軸と一致する。 The region E is a region in which the declination is larger than the declination of the initial zero-phase current value IRB0 held in the initial value holding unit 13 and is 150 degrees or less. The portion of the region E having an argument of 150 degrees coincides with the T-phase imaginary axis.
領域Ｆは、偏角が１５０度よりも大きく、２７０度（－９０度）以下の領域である。 The region F is a region having an argument larger than 150 degrees and 270 degrees (−90 degrees) or less.
零相電流ＩＲＢ１１と初期零相電流値ＩＲＢ０の差の電流ＩＲ１１の偏角が領域Ａに含まれる場合には、電流解析部１６は、差の電流ＩＲ１１をＲ相の抵抗分電流と、初期零相電流値ＩＲＢ０の偏角と同じ偏角の直線を軸としたＲ相及びＴ相の静電容量分電流とに分離する。 When the deviation angle of the current IR11 of the difference between the zero-phase current IRB11 and the initial zero-phase current value IRB0 is included in the region A, the current analysis unit 16 uses the difference current IR11 as the resistance component current of the R phase and the initial zero. The phase current value is separated into the R phase and T phase capacitance currents about a straight line with the same deviation angle as the deviation angle of IRB0.
また、相特定部１４は、電流解析部１６が分離した電流のうちＲ相の抵抗分電流が大きい場合には、Ｒ相の絶縁の劣化またはＲ相における地絡の発生と判定し、Ｒ相及びＴ相の静電容量分電流が大きい場合には、初期零相電流値ＩＲＢ０が流れる原因であったＲ相とＴ相の静電容量の減少と判定する。なお、入出力部１７には、相特定部１４が特定した零相電流ＩＲＢ１１の増加の原因、例えば、Ｒ相の絶縁の劣化またはＲ相における地絡の発生のみでなく、相特定部１４が特定しなかった原因、例えば、Ｒ相とＴ相の静電容量の減少についても画面表示するようにしてもよい。つまり、零相電流ＩＲＢ１１の増加の原因となる可能性を全て列記して表示するようにしてもよい。 Further, when the resistance component current of the R phase is large among the currents separated by the current analysis unit 16, the phase specifying unit 14 determines that the insulation of the R phase has deteriorated or a ground fault has occurred in the R phase, and the R phase has been determined. When the current is large by the capacitance of the T phase, it is determined that the capacitance of the R phase and the T phase, which was the cause of the initial zero-phase current value IRB0, is reduced. In the input / output unit 17, not only the cause of the increase in the zero-phase current IRB11 specified by the phase identification unit 14, for example, deterioration of the insulation of the R phase or the occurrence of a ground fault in the R phase, but also the phase identification unit 14 is provided. The cause not specified, for example, the decrease in the capacitance of the R phase and the T phase may be displayed on the screen. That is, all the possibilities that cause an increase in the zero-phase current IRB11 may be listed and displayed.
零相電流ＩＲＢ１１と初期零相電流値ＩＲＢ０の差の電流ＩＲ１１の偏角が領域Ｂに含まれる場合には、電流解析部１６は、次の４通りに電流ＩＲ１１を分離する。 When the declination of the current IR11, which is the difference between the zero-phase current IRB11 and the initial zero-phase current value IRB0, is included in the region B, the current analysis unit 16 separates the current IR11 in the following four ways.
電流解析部１６は、まず、電流ＩＲ１１を、図１４に示すように、電流ＩＲ１１Ａと電流ＩＲ１１Ｂとに分離する。電流ＩＲ１１Ａは、Ｒ相の抵抗分電流であり、電流ＩＲ１１Ｂは、Ｒ相の静電容量分電流である。 First, the current analysis unit 16 separates the current IR11 into a current IR11A and a current IR11B as shown in FIG. The current IR11A is the resistance component current of the R phase, and the current IR11B is the capacitance component current of the R phase.
また、電流解析部１６は、電流ＩＲ１１を、図１５に示すように、電流ＩＲ１１Ｃと電流ＩＲ１１Ｄとに分離する。電流ＩＲ１１Ｃは、Ｔ相の抵抗分電流であり、電流ＩＲ１１Ｄは、Ｔ相の静電容量分電流である。 Further, the current analysis unit 16 separates the current IR11 into the current IR11C and the current IR11D as shown in FIG. The current IR11C is a T-phase resistance component current, and the current IR11D is a T-phase capacitance component current.
また、電流解析部１６は、電流ＩＲ１１を、図１６に示すように、電流ＩＲ１１Ｅと電流ＩＲ１１Ｆとに分離する。電流ＩＲ１１Ｅは、Ｔ相の抵抗分電流であり、電流ＩＲ１１Ｆは、初期零相電流値ＩＲＢ０の偏角と同じ偏角の直線軸としたＲ相とＴ相の静電容量分電流である。 Further, the current analysis unit 16 separates the current IR11 into a current IR11E and a current IR11F as shown in FIG. The current IR11E is the resistance component current of the T phase, and the current IR11F is the capacitance component current of the R phase and the T phase having the same declination as the declination of the initial zero-phase current value IRB0.
さらに、電流解析部１６は、電流ＩＲ１１を、図１７に示すように、電流ＩＲ１１Ｇと電流ＩＲ１１Ｈとに分離する。電流ＩＲ１１Ｇは、Ｒ相の抵抗分電流であり、電流ＩＲ１１Ｈは、Ｔ相の抵抗分電流である。 Further, the current analysis unit 16 separates the current IR11 into a current IR11G and a current IR11H as shown in FIG. The current IR11G is the resistance component current of the R phase, and the current IR11H is the resistance component current of the T phase.
相特定部１４は、電流解析部１６が分離した電流の値の大きさに基づいて、零相電流ＩＲＢ１１の増加の原因を特定する。具体的には、Ｒ相の抵抗分電流が大きい場合には、Ｒ相の絶縁の劣化またはＲ相における地絡の発生と判定し、Ｒ相の静電容量分電流が大きい場合には、Ｒ相の静電容量の増大と判定し、Ｔ相の抵抗分電流が大きい場合には、Ｔ相の絶縁の劣化またはＴ相における地絡の発生と判定し、Ｔ相の静電容量分電流が大きい場合には、Ｔ相の静電容量の増大と判定し、Ｒ相及びＴ相の静電容量分電流が大きい場合には、初期零相電流値ＩＲＢ０が流れる原因であったＲ相とＴ相の静電容量の減少と判定する。また、Ｒ相の抵抗分電流とＴ相の抵抗分電流がともに大きい場合には、Ｒ相とＴ相の２相地絡と判定する。なお、入出力部１７には、零相電流ＩＲＢ１１の増加の原因となる可能性を全て列記して表示するようにしてもよい。 The phase specifying unit 14 identifies the cause of the increase in the zero-phase current IRB 11 based on the magnitude of the value of the current separated by the current analysis unit 16. Specifically, when the resistance current of the R phase is large, it is determined that the insulation of the R phase has deteriorated or the ground fault has occurred in the R phase, and when the capacitance current of the R phase is large, R If it is determined that the capacitance of the phase has increased and the resistance component current of the T phase is large, it is determined that the insulation of the T phase has deteriorated or a ground fault has occurred in the T phase, and the capacitance component current of the T phase has increased. If it is large, it is determined that the capacitance of the T phase is increased, and if the current is large by the capacitance of the R phase and the T phase, the initial zero phase current value IRB0 is the cause of the flow of the R phase and T. Judged as a decrease in the capacitance of the phase. When both the resistance component current of the R phase and the resistance component current of the T phase are large, it is determined to be a two-phase ground fault of the R phase and the T phase. The input / output unit 17 may list and display all the possibilities that cause an increase in the zero-phase current IRB11.
零相電流ＩＲＢ１１と初期零相電流値ＩＲＢ０の差の電流ＩＲ１１の偏角が領域Ｃに含まれる場合には、電流解析部１６は、差の電流ＩＲ１１をＴ相の抵抗分電流とＲ相の静電容量分電流、Ｔ相の抵抗分電流とＴ相の静電容量分電流、Ｔ相の静電容量分電流とＴ相の静電容量分電流の３通りに分離する。相特定部１４は、電流解析部１６が分離した電流の値の大きさに基づいて、零相電流ＩＲＢ１１の増加の原因を特定する。 When the deviation angle of the current IR11 of the difference between the zero-phase current IRB11 and the initial zero-phase current value IRB0 is included in the region C, the current analysis unit 16 uses the difference current IR11 as the T-phase resistance component current and the R-phase. It is separated into three types: electrostatic capacity current, T-phase resistance current and T-phase electrostatic capacity current, and T-phase electrostatic capacity current and T-phase electrostatic capacity current. The phase specifying unit 14 identifies the cause of the increase in the zero-phase current IRB 11 based on the magnitude of the value of the current separated by the current analysis unit 16.
零相電流ＩＲＢ１１と初期零相電流値ＩＲＢ０の差の電流ＩＲ１１の偏角が領域Ｄに含まれる場合には、電流解析部１６は、差の電流ＩＲ１１をＲ相の静電容量分電流とＲ相及びＴ相の静電容量分電流、
Ｒ相及びＴ相の静電容量分電流とＴ相の静電容量分電流、Ｒ相の静電容量分電流とＴ相の静電容量分電流の３通りに分離する。相特定部１４は、電流解析部１６が分離した電流の値の大きさに基づいて、零相電流ＩＲＢ１１の増加の原因を特定する。
When the deviation angle of the current IR11 of the difference between the zero-phase current IRB11 and the initial zero-phase current value IRB0 is included in the region D, the current analysis unit 16 uses the difference current IR11 as the R-phase capacitance current and R. Phase and T-phase capacitance current,
It is separated into three types: R-phase and T-phase capacitance component currents and T-phase capacitance component currents, and R-phase capacitance component currents and T-phase capacitance component currents. The phase specifying unit 14 identifies the cause of the increase in the zero-phase current IRB 11 based on the magnitude of the value of the current separated by the current analysis unit 16.
零相電流ＩＲＢ１１と初期零相電流値ＩＲＢ０の差の電流ＩＲ１１の偏角が領域Ｅに含まれる場合には、電流解析部１６は、差の電流ＩＲ１１をＲ相の静電容量分電流とＲ相及びＴ相の静電容量分電流、
Ｒ相及びＴ相の静電容量分電流とＴ相の静電容量分電流、Ｒ相の静電容量分電流とＴ相の静電容量分電流の３通りに分離する。相特定部１４は、電流解析部１６が分離した電流の値の大きさに基づいて、零相電流ＩＲＢ１１の増加の原因を特定する。
When the deviation angle of the current IR11 of the difference between the zero-phase current IRB11 and the initial zero-phase current value IRB0 is included in the region E, the current analysis unit 16 uses the difference current IR11 as the R-phase capacitance current and R. Phase and T-phase capacitance current,
It is separated into three types: R-phase and T-phase capacitance component currents and T-phase capacitance component currents, and R-phase capacitance component currents and T-phase capacitance component currents. The phase specifying unit 14 identifies the cause of the increase in the zero-phase current IRB 11 based on the magnitude of the value of the current separated by the current analysis unit 16.
零相電流ＩＲＢ１１と初期零相電流値ＩＲＢ０の差の電流ＩＲ１１の偏角が領域Ｆに含まれる場合には、電流解析部１６は、差の電流ＩＲ１１をＴ相の静電容量分電流とＲ相及びＴ相の静電容量分電流とに分離する。相特定部１４は、電流解析部１６が分離した電流の値の大きさに基づいて、零相電流ＩＲＢ１１の増加の原因を特定する。 When the deviation angle of the current IR11 of the difference between the zero-phase current IRB11 and the initial zero-phase current value IRB0 is included in the region F, the current analysis unit 16 uses the difference current IR11 as the T-phase capacitance current and R. It is separated into the current for the capacitance of the phase and the T phase. The phase specifying unit 14 identifies the cause of the increase in the zero-phase current IRB 11 based on the magnitude of the value of the current separated by the current analysis unit 16.
なお、三相３線回路の場合も、監視装置１０は、複素平面上に電流を表すような表示を入出力部１７に行わせてもよい。 Even in the case of a three-phase three-wire circuit, the monitoring device 10 may cause the input / output unit 17 to display a current on a complex plane.
５．他回路による地絡の発生
ところで、実際には、対地静電容量が大きい場合、各相の対地静電容量が変化しなくとも、静電容量分電流が大きく変化し、零相電流ＩＲＢの増加の原因として特定される場合がある。これは、他の電力回路で地絡が発生した場合、例えば、監視装置１０が変圧器２１の二次側回路の一方を監視している際に変圧器２１の他方の二次側回路に地絡が発生した場合に生じる現象である。
5. Occurrence of ground faults due to other circuits In reality, when the ground capacitance is large, even if the ground capacitance of each phase does not change, the current changes significantly by the capacitance and the zero-phase current IRB increases. May be identified as the cause of. This means that if a ground fault occurs in another power circuit, for example, when the monitoring device 10 is monitoring one of the secondary circuits of the
監視装置１０が監視している電力回路とは他の電力回路に地絡が生じた場合、大地と監視装置１０が監視している電力回路の対地静電容量を含む回路が形成されることがあり、この場合には、監視装置１０は、静電容量分電流の変化を検出することとなる。 What is the power circuit monitored by the monitoring device 10? When a ground fault occurs in another power circuit, a circuit including the ground and the ground capacitance of the power circuit monitored by the monitoring device 10 may be formed. In this case, the monitoring device 10 will detect the change in the current by the capacitance.
このとき、監視装置１０が監視している電力回路の対地静電容量が大きい場合、それ自体は変化しなくても、検出される電流は、初期零相電流値ＩＲＢ０の偏角の軸に沿ったもの（初期零相電流値ＩＲＢ０の偏角と同じ偏角またはその偏角と１８０度異なる偏角であらわされる電流）となる。 At this time, when the capacitance to ground of the power circuit monitored by the monitoring device 10 is large, the detected current is along the axis of the declination of the initial zero-phase current value IRB0 even if it does not change itself. (The current represented by the same declination as the declination of the initial zero-phase current value IRB0 or the declination 180 degrees different from the declination).
したがって、監視装置１０は、入出力部１７に零相電流の増加の原因となる可能性を全て列記して画面表示する際に、他の電力回路での地絡発生の可能性も列記し、零相電流の増加の原因の特定を容易に把握できるようにしてもよい。 Therefore, when the monitoring device 10 lists all the possibilities of causing an increase in the zero-phase current in the input / output unit 17 and displays it on the screen, it also lists the possibility of ground faults in other power circuits. It may be possible to easily identify the cause of the increase in the zero-phase current.
６．監視装置１０の運用の流れ
次に、監視装置１０の運用の流れについて説明する。図１８は、監視装置１０の運用の流れを示すフローチャートである。
6. Operation flow of the monitoring device 10 Next, the operation flow of the monitoring device 10 will be described. FIG. 18 is a flowchart showing the operation flow of the monitoring device 10.
（Ｓ１０１）
監視装置１０の運用に際しては、まず、対象となる配線路の健全化試験を行う。この健全化試験では、配線路の絶縁が十分であることを確認する。
(S101)
When operating the monitoring device 10, first, a soundness test of the target wiring line is performed. In this sanitization test, it is confirmed that the insulation of the wiring line is sufficient.
（Ｓ１０２でＮＯ、Ｓ１０３）
健全化試験に合格しなかった場合は、配線路の工事等を含む健全化処理を行う。
(NO in S102, S103)
If it does not pass the sanitization test, it will be sanitized including the construction of wiring lines.
（Ｓ１０２でＹＥＳ、Ｓ１０４）
健全化試験に合格した場合は、続いて初期値の測定を行う。測定する値は、配線路の各相の対地静電容量と、所定の部分の電圧である。なお、対地静電容量の測定に代えて、監視装置１０を動作させて初期零相電流値ＩＲＢ０を測定するようにしてもよい。
(YES in S102, S104)
If the soundness test is passed, the initial value is subsequently measured. The values to be measured are the capacitance to ground of each phase of the wiring line and the voltage of a predetermined portion. Instead of measuring the capacitance to ground, the monitoring device 10 may be operated to measure the initial zero-phase current value IRB0.
（Ｓ１０５）
初期値の測定が終了すると、測定した値に基づいて、初期零相電流値ＩＲＢ０を算出し、算出した値を監視装置１０に入力する。なお、監視装置１０を動作させて初期零相電流値ＩＲＢ０を測定した場合には、この処理を省略することができる。
(S105)
When the measurement of the initial value is completed, the initial zero-phase current value IRB0 is calculated based on the measured value, and the calculated value is input to the monitoring device 10. When the monitoring device 10 is operated and the initial zero-phase current value IRB0 is measured, this process can be omitted.
（Ｓ１０６）
初期値の入力が終了すると、監視装置１０を動作させ、運用を開始する。
(S106)
When the input of the initial value is completed, the monitoring device 10 is operated and the operation is started.
７．監視装置１０の動作の流れ
次に、監視装置１０の動作の流れを説明する。図１９及び図２０は、監視装置１０の動作の流れを示すフローチャートである。
7. Operation flow of the monitoring device 10 Next, the operation flow of the monitoring device 10 will be described. 19 and 20 are flowcharts showing the operation flow of the monitoring device 10.
（Ｓ２０１）
監視装置１０は、動作を開始すると、零相電流測定部１１が測定した零相電流を取得する。
(S201)
When the monitoring device 10 starts operation, the monitoring device 10 acquires the zero-phase current measured by the zero-phase current measuring unit 11.
（Ｓ２０２）
続いて、監視装置１０は、前述した方法による計算を行う。
(S202)
Subsequently, the monitoring device 10 performs the calculation by the method described above.
（Ｓ２０３）
そして、その計算結果を保存する。
(S203)
Then, the calculation result is saved.
（Ｓ２０４でＮＯ）
零相電流を取得と、計算処理、計算結果の保存は、計算結果のうち所定の電流値が監視レベルを超過しない限り、定期的または連続して行う。
(NO in S204)
Acquisition of zero-phase current, calculation processing, and storage of calculation results are performed periodically or continuously as long as the predetermined current value of the calculation results does not exceed the monitoring level.
（Ｓ２０４でＹＥＳ）
一方、計算結果のうち所定の電流値、例えば、各相の抵抗分電流値が監視レベルを超過した場合には、地絡が発生したと判定する。
(YES in S204)
On the other hand, when a predetermined current value in the calculation result, for example, the resistance current value of each phase exceeds the monitoring level, it is determined that a ground fault has occurred.
（Ｓ２０５）
監視装置１０は、地絡が発生したと判定した場合に、遮断器を動作させるための遮断信号を出力する。
(S205)
When it is determined that a ground fault has occurred, the monitoring device 10 outputs a circuit breaker signal for operating the circuit breaker.
（Ｓ２０６）
続いて、警報信号を出力する。
(S206)
Subsequently, an alarm signal is output.
（Ｓ２０７）
そして、Ｓ２０３で保存した計算結果等を入出力部１７に表示し、動作を終了する。
(S207)
Then, the calculation result and the like saved in S203 are displayed on the input / output unit 17, and the operation is terminated.
（Ｓ３０１でＹＥＳ、Ｓ３０２）
また、地絡が発生していない状態で、管理者等により情報表示の要求があった場合には、Ｓ２０３で保存した計算結果を取得する。
(YES in S301, S302)
Further, when the administrator or the like requests information display in a state where no ground fault has occurred, the calculation result saved in S203 is acquired.
（Ｓ３０３）
そして、取得した計算結果等を入出力部１７に表示する。
(S303)
Then, the acquired calculation result or the like is displayed on the input / output unit 17.
（Ｓ３０４でＹＥＳ、Ｓ３０５）
入出力部１７に表示した画面等は、所定時間の経過に伴って消去する。もちろん、管理者等の操作により、画面を消去しても良い。
(YES in S304, S305)
The screen or the like displayed on the input / output unit 17 is erased with the lapse of a predetermined time. Of course, the screen may be erased by an operation of an administrator or the like.
以上説明した構成と処理により、電力回路に絶縁の劣化や対地静電容量の変化が生じた場合や地絡が発生した場合に、これらの発生した相とその原因を容易に特定することが可能となる。 With the configuration and processing described above, it is possible to easily identify the phases in which they occur and their causes when insulation deteriorates in the power circuit, changes in capacitance to ground occur, or ground faults occur. Will be.
また、電力の送電部に設置する零相変流器（ＺＣＴ）が検出する地絡電流の大きさと地絡点の地絡電流の大きさに２倍以上の差を生じることがあるため、 零相電流そのままを検出する現行の地絡電流検出技術では地絡点の電流を正確に検出できないが、監視装置１０では、地絡点の電流を正確に検出することができる。 In addition, there may be a difference of more than double between the magnitude of the ground fault current detected by the zero-phase current transformer (ZCT) installed in the power transmission section and the magnitude of the ground fault current at the ground fault point. The current ground fault current detection technique that detects the phase current as it is cannot accurately detect the current at the ground fault point, but the monitoring device 10 can accurately detect the current at the ground fault point.
なお、以上説明した監視装置１０は、計測器、漏電遮断器（ＥＬＣＢ）、配線用遮断器（ＭＣＣＢ）、絶縁監視装置、地絡継電器等に組み込む形で、利用することも可能である。 The monitoring device 10 described above can also be used by incorporating it into a measuring instrument, an earth-leakage circuit breaker (ELCB), a molded case circuit breaker (MCCB), an insulation monitoring device, a ground relay, or the like.
＜その他＞
本発明は、以下の態様でも実施可能である。
<Others>
The present invention can also be implemented in the following aspects.
コンピュータを、電力回路の地絡電流を検出又は監視する装置として機能させるプログラムであって、前記監視装置は、零相電流取得部と位相差特定部と初期値保持部と相特定部とを備え、前記零相電流取得部は、前記電力回路の零相電流の大きさを取得可能に構成され、前記位相差特定部は、前記電力回路の所定部分の電圧に基づいて該電圧と前記零相電流取得部が取得した零相電流との位相差を特定可能に構成され、前記初期値保持部は、前記電力回路の初期状態における零相電流を複素数で表現した値を初期零相電流値として記憶保持し、前記相特定部は、前記零相電流取得部が取得した零相電流の大きさと前記位相差特定部が特定した位相差とに基づいて前記電力回路の零相電流を複素数で表現した値と前記初期値保持部が記憶保持する初期零相電流値との差を算出し、該算出した差の偏角が前記電力回路の種別に応じて定めた複数の範囲のいずれに属するかを判定し、該判定の結果に基づいて前記電力回路の零相電流の発生相とその原因を特定可能に構成される、プログラム。 A program that causes a computer to function as a device for detecting or monitoring a ground fault current in a power circuit, the monitoring device including a zero-phase current acquisition unit, a phase difference specifying unit, an initial value holding unit, and a phase specifying unit. The zero-phase current acquisition unit is configured to be able to acquire the magnitude of the zero-phase current of the power circuit, and the phase difference specifying unit has the voltage and the zero-phase based on the voltage of a predetermined portion of the power circuit. The initial value holding unit is configured so that the phase difference from the zero-phase current acquired by the current acquisition unit can be specified, and the initial value holding unit uses a value expressed by a complex number of the zero-phase current in the initial state of the power circuit as the initial zero-phase current value. The phase identification unit expresses the zero-phase current of the power circuit as a complex number based on the magnitude of the zero-phase current acquired by the zero-phase current acquisition unit and the phase difference specified by the phase difference identification unit. The difference between the calculated value and the initial zero-phase current value stored and held by the initial value holding unit is calculated, and which of the plurality of ranges determined according to the type of the power circuit belongs to the deviation angle of the calculated difference. A program configured to be able to identify the generated phase of the zero-phase current of the power circuit and its cause based on the result of the determination.
１０ ：監視装置
１１ ：零相電流測定部
１２ ：位相差特定部
１３ ：初期値保持部
１４ ：相特定部
１５ ：回転処理部
１６ ：電流解析部
１７ ：入出力部
２０ ：商用電源
２１ ：変圧器
２２ ：変圧器
２３ ：変圧器
２４ ：負荷
２５ ：負荷
２６ ：負荷
２７ ：負荷
２８ ：負荷
２９ ：負荷
ＩＲ１ ：電流
ＩＲ２ ：電流
ＩＲ３ ：電流
ＩＲ４ ：電流
ＩＲ５ ：電流
ＩＲ１０ ：電流
ＩＲＢ０ ：初期零相電流値
ＩＲＢ１ ：零相電流
ＩＲＢ２ ：零相電流
ＩＲＢ３ ：零相電流
ＩＲＢ４ ：零相電流
ＩＲＢ５ ：零相電流
ＩＲＢ１１ ：零相電流
10: Monitoring device 11: Zero-phase current measuring unit 12: Phase difference specifying unit 13: Initial value holding unit 14: Phase specifying unit 15: Rotation processing unit 16: Current analysis unit 17: Input / output unit 20: Commercial power supply 21: Transformation Instrument 22: Transformer 23: Transformer 24: Load 25: Load 26: Load 27: Load 28: Load 29: Load IR1: Current IR2: Current IR3: Current IR4: Current IR5: Current IR10: Current IRB0: Initial zero phase Current value IRB1: Zero-phase current IRB2: Zero-phase current IRB3: Zero-phase current IRB4: Zero-phase current IRB5: Zero-phase current IRB11: Zero-phase current
Claims (12)
零相電流測定部と位相差特定部と初期値保持部と相特定部とを備え、
前記零相電流測定部は、前記電力回路の零相電流の大きさを測定可能に構成され、
前記位相差特定部は、前記電力回路の所定部分の電圧に基づいて該電圧と前記零相電流測定部が測定した零相電流との位相差を特定可能に構成され、
前記初期値保持部は、前記電力回路の初期状態における零相電流を特定可能な値を初期値として記憶保持し、
前記相特定部は、前記零相電流測定部が測定した零相電流の大きさと前記位相差特定部が特定した位相差とに基づいて前記電力回路の零相電流を複素数で表現した値と、前記初期値保持部が記憶保持する初期値から特定される零相電流を複素数で表現した値との差を算出し、該算出した差の偏角が前記電力回路の種別に応じて定めた複数の範囲のいずれに属するかを判定し、該判定の結果に基づいて前記電力回路の零相電流の発生相とその原因を特定可能に構成される、
装置。 A device that detects or monitors the ground fault current of a power circuit.
It is equipped with a zero-phase current measuring unit, a phase difference specifying unit, an initial value holding unit, and a phase specifying unit.
The zero-phase current measuring unit is configured to be capable of measuring the magnitude of the zero-phase current of the power circuit.
The phase difference specifying unit is configured to be able to specify the phase difference between the voltage and the zero-phase current measured by the zero-phase current measuring unit based on the voltage of a predetermined portion of the power circuit.
The initial value holding unit stores and holds a value that can specify the zero-phase current in the initial state of the power circuit as an initial value.
The phase specifying unit includes a value expressed by a complex number of the zero phase current of the power circuit based on the magnitude of the zero phase current measured by the zero phase current measuring unit and the phase difference specified by the phase difference specifying unit. A plurality of values obtained by calculating the difference between the zero-phase current specified by the initial value holding unit and the value expressed by a complex number and having the deviation angle of the calculated difference determined according to the type of the power circuit. It is configured so that it can be determined which of the ranges of the above, and based on the result of the determination, the generated phase of the zero-phase current of the power circuit and its cause can be identified.
Device.
前記初期値保持部は、前記ケーブル又は前記バスダクトの対地静電容量値または該対地静電容量値に基づいて算出される零相電流を複素数で表現した値を初期値として記憶保持する請求項１に記載の装置。 The power circuit corresponds to either high voltage, extra high voltage, or ultra high voltage and includes a cable or bus duct.
The initial value holding unit stores and holds as an initial value a value expressed by a complex number of a zero-phase current calculated based on the ground capacitance value of the cable or the bus duct or the ground capacitance value. The device described in.
前記初期値保持部は、前記ケーブル又は前記バスダクトの対地静電容量値または該対地静電容量値に基づいて算出される零相電流を複素数で表現した値を初期値として記憶保持する請求項１に記載の装置。 The power circuit is low voltage and includes cables buried underground or bus ducts laid indoors.
The initial value holding unit stores and holds as an initial value a value expressed by a complex number of a zero-phase current calculated based on the ground capacitance value of the cable or the bus duct or the ground capacitance value. The device described in.
前記電流解析部は、前記相特定部が算出した差を、前記相特定部が特定した相の抵抗分電流値と静電容量電流値とに分離可能に構成される
請求項１乃至請求項４のいずれか１項に記載の装置。 Further equipped with a current analysis unit,
Claims 1 to 4 are configured such that the current analysis unit can separate the difference calculated by the phase identification unit into the resistance component current value and the capacitance current value of the phase specified by the phase identification unit. The device according to any one of the above items.
前記回転処理部は、前記差の偏角を前記電力回路の種別に応じた角度だけ回転可能に構成され、
前記相特定部は、前記回転処理部で回転された差の偏角に基づいて前記電力回路の零相電流の発生原因となる相を特定する
請求項１乃至請求項５のいずれか１項に記載の装置。 The phase specifying unit includes a rotation processing unit.
The rotation processing unit is configured to be able to rotate the declination angle of the difference by an angle corresponding to the type of the power circuit.
The phase specifying unit is according to any one of claims 1 to 5, which specifies a phase that causes a zero-phase current to be generated in the power circuit based on the declination of the difference rotated by the rotation processing unit. The device described.
前記回転処理部は、前記差の偏角を１２０度回転させる処理と前記差の偏角を２４０度回転させる処理とを行う
請求項６に記載の装置。 The power circuit includes a three-phase three-wire circuit with either low voltage, extra high voltage, or ultra-high voltage grounded neutral, a three-phase four-wire circuit grounded with low voltage neutral, and low-voltage or high-voltage non-voltage. It is one of the grounded three-phase three-wire circuits,
The apparatus according to claim 6, wherein the rotation processing unit performs a process of rotating the argument of the difference by 120 degrees and a process of rotating the argument of the difference by 240 degrees.
前記回転処理部は、前記差の偏角を－３０度または－６０度回転させる処理を行う
請求項６に記載の装置。 The power circuit is a three-phase three-wire circuit with a triangular winding on the low-voltage side of the transformer and one-phase grounding, and a star-type winding on the high-voltage side of the transformer.
The device according to claim 6, wherein the rotation processing unit performs a process of rotating the declination angle of the difference by -30 degrees or -60 degrees.
前記回転処理部は、前記差の偏角を－６０度または－１２０度回転させる処理を行う
請求項６に記載の装置。 The power circuit is a three-phase three-wire circuit with a triangular winding on the low-voltage side of the transformer and one-phase grounding, and a triangular winding on the high-voltage side of the transformer.
The device according to claim 6, wherein the rotation processing unit performs a process of rotating the declination angle of the difference by -60 degrees or −120 degrees.
前記入出力部は、前記相特定部が特定した相とその原因を１又は複数表示可能に構成される請求項１乃至請求項９のいずれか１項に記載の装置。 With more input / output
The device according to any one of claims 1 to 9, wherein the input / output unit is configured to be capable of displaying one or more of the phase specified by the phase specifying unit and its cause.
前記装置は、零相電流取得部と位相差特定部と初期値保持部と相特定部とを備え、
前記零相電流取得部は、前記電力回路の零相電流の大きさを取得可能に構成され、
前記位相差特定部は、前記電力回路の所定部分の電圧に基づいて該電圧と前記零相電流取得部が取得した零相電流との位相差を特定可能に構成され、
前記初期値保持部は、前記電力回路の初期状態における零相電流を特定可能な値を初期値として記憶保持し、
前記相特定部は、前記零相電流取得部が取得した零相電流の大きさと前記位相差特定部が特定した位相差とに基づいて前記電力回路の零相電流を複素数で表現した値と、前記初期値保持部が記憶保持する初期値から特定される零相電流を複素数で表現した値との差を算出し、該算出した差の偏角が前記電力回路の種別に応じて定めた複数の範囲のいずれに属するかを判定し、該判定の結果に基づいて前記電力回路の零相電流の発生相とその原因を特定可能に構成される、
プログラム。 A program that causes a computer to function as a device for detecting or monitoring the ground fault current of a power circuit.
The device includes a zero-phase current acquisition unit, a phase difference specifying unit, an initial value holding unit, and a phase specifying unit.
The zero-phase current acquisition unit is configured to be able to acquire the magnitude of the zero-phase current of the power circuit.
The phase difference specifying unit is configured to be able to specify the phase difference between the voltage and the zero-phase current acquired by the zero-phase current acquisition unit based on the voltage of a predetermined portion of the power circuit.
The initial value holding unit stores and holds a value that can specify the zero-phase current in the initial state of the power circuit as an initial value.
The phase specifying unit includes a value expressed by a complex number of the zero phase current of the power circuit based on the magnitude of the zero phase current acquired by the zero phase current acquiring unit and the phase difference specified by the phase difference specifying unit. A plurality of values obtained by calculating the difference between the zero-phase current specified by the initial value holding unit and the value expressed by a complex number and having the deviation angle of the calculated difference determined according to the type of the power circuit. It is configured so that it can be determined which of the ranges of the above, and based on the result of the determination, the generated phase of the zero-phase current of the power circuit and its cause can be identified.
program.
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| JP3676486B2 (en) * | 1996-03-25 | 2005-07-27 | 株式会社キューヘン | Ground fault detection device |
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| CN101038316A (en) | 2007-04-23 | 2007-09-19 | 国电南京自动化股份有限公司 | Circuit protection order component phase selectiing method using both end information |
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