JPH07154920A - Method of detecting single operation - Google Patents
Method of detecting single operationInfo
- Publication number
- JPH07154920A JPH07154920A JP5296173A JP29617393A JPH07154920A JP H07154920 A JPH07154920 A JP H07154920A JP 5296173 A JP5296173 A JP 5296173A JP 29617393 A JP29617393 A JP 29617393A JP H07154920 A JPH07154920 A JP H07154920A
- Authority
- JP
- Japan
- Prior art keywords
- value
- reference value
- difference
- detection
- harmonic component
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
Landscapes
- Photovoltaic Devices (AREA)
- Supply And Distribution Of Alternating Current (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、系統連系システムにお
ける単独運転検出方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting an isolated operation in a system interconnection system.
【０００２】[0002]
【従来の技術】近年、太陽電池や燃料電池などの数ＫＷ
程度の直流電源と、その出力を交流に変換するインバー
タとを備えた分散電源設備を商用電力系統と連系（接
続）し、家電製品などの負荷に給電する系統連系システ
ムが種々提案されている。2. Description of the Related Art In recent years, several kW for solar cells, fuel cells, etc.
Various grid-connected systems have been proposed that connect (connect) a distributed power supply system equipped with a DC power supply of a certain degree and an inverter that converts its output to AC with a commercial power grid to supply power to loads such as home appliances. There is.
【０００３】系統連系システムでは、商用電力系統の保
全作業の安全を確保するため、商用電力系統の不測の停
電時及び作業停電時において、直ちにインバータの動作
を停止させるか、又は直ちに開閉器を作動させて連系を
解除することにより、インバータを商用電力系統から解
列させる機能、すなわちインバータの単独運転を防止す
る機能が不可欠である。In the grid interconnection system, in order to ensure the safety of maintenance work of the commercial power system, the operation of the inverter is immediately stopped or the switch is immediately opened in the event of an unexpected power failure or work power failure of the commercial power system. It is essential to have a function of disconnecting the inverter from the commercial power system by operating it to release the interconnection, that is, a function of preventing the inverter from operating independently.
【０００４】電流制御形インバータを用いたシステムに
おいては、系統停電時に柱上トランスの励磁特性に起因
した第３次高調波電圧が発生するので、連系点電圧の第
３次高調波成分を検出して平常時に対する増加の度合い
を判定することにより、インバータの単独運転状態を検
出することができる。In a system using a current control type inverter, a third harmonic voltage due to the excitation characteristic of a pole transformer is generated during a system power failure, so that the third harmonic component of the interconnection point voltage is detected. By determining the degree of increase with respect to the normal condition, the islanding operation state of the inverter can be detected.
【０００５】しかし、図４（Ａ）に示すように、判定の
基準値として固定値を設定し、基準値と第３次高調波成
分の検出値との差が閾値を越えるか否かを判定する単純
閾値判定による場合には、商用電力系統に接続される多
種多様の負荷の中に第３次高調波発生源があったとき
に、誤検出の発生するおそれがある。However, as shown in FIG. 4 (A), a fixed value is set as a reference value for determination, and it is determined whether or not the difference between the reference value and the detected value of the third harmonic component exceeds a threshold value. According to the simple threshold determination, if there is a third harmonic generation source in a variety of loads connected to the commercial power system, there is a possibility that erroneous detection may occur.
【０００６】そこで、図４（Ｂ）に示すように、一定の
周期で第３高調波成分を検出し、前回の検出値を基準値
として増加の度合いを判定する差分判定を行う方法、す
なわち第３高調波成分の急激な増大を検出する単独運転
検出方法が提案されている。Therefore, as shown in FIG. 4B, a method of detecting the third harmonic component at a constant cycle and making a difference judgment for judging the degree of increase with the previous detection value as a reference value, that is, An islanding operation detection method has been proposed which detects a sudden increase in the third harmonic component.
【０００７】[0007]
【発明が解決しようとする課題】上述の差分判定によれ
ば、平常時において比較的に第３高調波電圧のレベルが
高くなることがあっても、それに応じて判定の基準値が
変更されるので、単純閾値判定の不都合を解消すること
ができる。ただし、突発的なノイズによって、基準値が
正規の値（真の平常レベル）とかけ離れた値になる場合
がある。その場合には、次に得られた検出値に対して正
しい差分判定を行うことができず、第３高調波の急増を
見逃したり、不要に第３高調波検出信号を発してしまう
おそれがある。つまり、従来の検出方法は、ノイズの影
響を受け易いという問題があった。According to the above-described difference determination, even if the level of the third harmonic voltage may be relatively high in normal times, the determination reference value is changed accordingly. Therefore, the inconvenience of the simple threshold value determination can be eliminated. However, due to sudden noise, the reference value may deviate from the normal value (true normal level). In that case, a correct difference determination cannot be performed on the detected value obtained next, and there is a possibility that a sudden increase in the third harmonic may be overlooked or a third harmonic detection signal may be emitted unnecessarily. . That is, the conventional detection method has a problem that it is easily affected by noise.
【０００８】本発明は、このような問題に鑑み、ノイズ
の影響を抑えて検出精度を高めることを目的としてい
る。In view of the above problems, the present invention aims to suppress the influence of noise and improve the detection accuracy.
【０００９】[0009]
【課題を解決するための手段】請求項１の発明に係る方
法は、上述の課題を解決するため、一定の周期で、イン
バータと商用電力系統との連系点における電圧の第３高
調波成分を検出するとともに、その検出値と基準値との
差を求めて閾値と比較する差分判定を行うことにより、
前記第３高調波成分の急増を検出する単独運転検出方法
であって、各回の差分判定において前記検出値と基準値
との差が前記閾値を越えない場合には、次回の差分判定
の基準値として前記検出値と現時点の基準値との荷重平
均値を設定する方法である。In order to solve the above-mentioned problems, the method according to the invention of claim 1 is, in order to solve the above-mentioned problems, the third harmonic component of the voltage at the connection point between the inverter and the commercial power system at a constant cycle. By detecting the difference between the detected value and the reference value and comparing with the threshold value,
An isolated operation detection method for detecting a sudden increase in the third harmonic component, wherein the difference between the detection value and the reference value does not exceed the threshold value in each difference determination, and the reference value for the next difference determination. Is a method of setting a weighted average value of the detected value and the reference value at the present time.
【００１０】請求項２の発明に係る方法は、前記荷重平
均値の設定に際して、前記現時点の基準値の重み付け
を、前記検出値の重み付けよりも大きくする方法であ
る。請求項３の発明に係る方法は、前記検出値と基準値
との差が前記閾値を越えた場合には、前記現時点の基準
値を保持した状態で、前記第３高調波成分の検出及びそ
の後の差分判定を行い、一定時間にわたって検出値と基
準値との差が連続して前記閾値を越えたときに、前記第
３高調波成分の急増を示す検出信号を発する方法であ
る。According to a second aspect of the present invention, when setting the weighted average value, the weighting of the reference value at the present time is made larger than the weighting of the detected value. In the method according to the invention of claim 3, when the difference between the detected value and the reference value exceeds the threshold value, the third reference harmonic component is detected and thereafter while maintaining the reference value at the present time. Is performed, and when the difference between the detected value and the reference value continuously exceeds the threshold value for a certain period of time, the detection signal indicating the rapid increase of the third harmonic component is emitted.
【００１１】[0011]
【作用】平常時において、第３高調波成分の急増の有無
を判定するための基準値は、第３高調波成分を検出する
毎に更新される。新たな基準値は、前回の検出時に設定
された現時点の基準値と今回の第３高調波成分の検出値
との荷重平均値とされ、そのとき現時点の基準値に大き
な重み付けが与えられる。In normal operation, the reference value for determining the presence / absence of a sudden increase in the third harmonic component is updated every time the third harmonic component is detected. The new reference value is a weighted average value of the reference value at the present time set at the time of the previous detection and the detected value of the third harmonic component at this time, and a large weight is given to the reference value at the present time.
【００１２】これにより、図３に示すように、ノイズに
起因する基準値の変動が抑えられ、常に基準値はノイズ
の無い理想状態における第３高調波成分の値に近い値と
なる。その結果、次回の検出で得られた検出値に対して
適正な差分判定を行うことができ、単独運転の誤検出を
防止することができる。As a result, as shown in FIG. 3, the fluctuation of the reference value due to noise is suppressed, and the reference value is always close to the value of the third harmonic component in the ideal state without noise. As a result, an appropriate difference determination can be performed on the detection value obtained in the next detection, and erroneous detection of isolated operation can be prevented.
【００１３】また、検出値と基準値との差が閾値を越え
る状態が一定時間にわたって継続したときに、つまり、
連続した複数回の差分判定で同様の結果が得られたとき
に、第３高調波成分の急増を示す検出信号が発せられ
る。これにより、さらに確実な単独運転の検出を実現す
ることができる。When the difference between the detected value and the reference value exceeds the threshold value for a certain period of time, that is,
When the same result is obtained by successive difference determinations, a detection signal indicating a sharp increase in the third harmonic component is issued. As a result, more reliable detection of isolated operation can be realized.
【００１４】[0014]
【実施例】図１は本発明を適用した単独運転検出装置４
０を有する太陽光発電システム１のブロック図、図２は
単独運転検出処理のフローチャートである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an islanding operation detection device 4 to which the present invention is applied.
FIG. 2 is a block diagram of the photovoltaic power generation system 1 having 0, and FIG. 2 is a flowchart of islanding operation detection processing.
【００１５】図１において、太陽光発電システム１は、
定格電圧が２００Ｖ程度の太陽電池１０、電圧形電流制
御方式のインバータ２０、系統保護用の開閉装置３０、
及び単独運転検出装置４０から構成され、図示しない配
電盤や電力計などを介して商用電力系統２と連系されて
いる。配電線Ｌには各種の家電製品などの負荷Ｚが接続
されている。In FIG. 1, the solar power generation system 1 is
A solar cell 10 having a rated voltage of about 200 V, a voltage source current control type inverter 20, a system protection switchgear 30,
And the islanding operation detection device 40, and is connected to the commercial power system 2 via a switchboard, a power meter, etc. not shown. A load Z such as various home appliances is connected to the distribution line L.
【００１６】インバータ２０は、複数のスイッチング素
子からなるインバータ回路２１及びその制御系２２を有
している。制御系２２は、変流器２３により検出された
インバータ回路２１の出力電流、変圧器２４により検出
された連系点電圧Ｖ、及び図示しないアイソレーション
アンプなどにより検出された太陽電池１０の出力電圧に
基づいて、運転力率が１になり且つ太陽電池１０から最
大電力を引き出すように、インバータ回路２１の出力電
流のＰＷＭ制御を行う。The inverter 20 has an inverter circuit 21 composed of a plurality of switching elements and a control system 22 thereof. The control system 22 outputs the output current of the inverter circuit 21 detected by the current transformer 23, the interconnection point voltage V detected by the transformer 24, and the output voltage of the solar cell 10 detected by an isolation amplifier (not shown). Based on the above, PWM control of the output current of the inverter circuit 21 is performed so that the driving power factor becomes 1 and the maximum power is drawn from the solar cell 10.
【００１７】単独運転検出装置４０は、入力レベル調整
部４１、適当にレベル調整された連系点電圧Ｖから第３
次高調波成分を抽出するバンドパスフィルタ４２、抽出
された第３次高調波成分の全波整流を行う絶対値回路４
３、第３次高調波成分の振幅に応じたレベルの信号を出
力する積分回路４４、及び積分回路４４の出力を取り込
んで第３次高調波成分の急増を検出するマイクロコンピ
ュータ４５から構成されている。The islanding operation detecting device 40 comprises an input level adjusting section 41, a third level based on an appropriately level-adjusted interconnection point voltage V.
A band pass filter 42 for extracting the third harmonic component, an absolute value circuit 4 for performing full-wave rectification of the extracted third harmonic component
3, an integrating circuit 44 that outputs a signal of a level corresponding to the amplitude of the third harmonic component, and a microcomputer 45 that captures the output of the integrating circuit 44 and detects a sudden increase in the third harmonic component. There is.
【００１８】次に、図２を参照して、マイクロコンピュ
ータ４５が実行する単独運転検出処理について説明す
る。マイクロコンピュータ４５内の図示しないＣＰＵ
は、アナログポートに入力された高調波抽出信号Ｓｈｖ
を、一定周期（例えば１０ｍｓ）でサンプリングし、そ
れと並行して複数回分（例えば５回分）のサンプリング
値の平均値を求め、その平均値を第３次高調波成分の検
出値Ｖｉｎとして取り込む。つまり、ＣＰＵによって、
５０（＝１０×５）ｍｓの周期で第３次高調波成分が検
出される（＃１１）。Next, with reference to FIG. 2, the islanding operation detection process executed by the microcomputer 45 will be described. CPU (not shown) in the microcomputer 45
Is the harmonic extraction signal Shv input to the analog port
Is sampled at a constant cycle (for example, 10 ms), an average value of sampling values for a plurality of times (for example, 5 times) is calculated in parallel, and the average value is taken in as the detection value Vin of the third harmonic component. In other words, by the CPU
The third harmonic component is detected at a cycle of 50 (= 10 × 5) ms (# 11).
【００１９】インバータ２０による連系運転を開始した
直後、例えばインバータ回路２１の起動から１秒以内の
期間は、インバータ回路２１の出力が不安定であって、
インバータ回路２１の出力に第３次高調波成分が比較的
に多く含まれることがあるので、この期間は第３次高調
波成分の急増の有無の判定（差分判定）を避け、後の差
分判定の準備として基準値の更新を行う（＃１２，１
７）。Immediately after the interconnection operation by the inverter 20 is started, for example, the output of the inverter circuit 21 is unstable for a period of 1 second or less after the start of the inverter circuit 21,
Since the output of the inverter circuit 21 may include a relatively large amount of the third-order harmonic component, during this period, the determination as to whether or not the third-order harmonic component has rapidly increased (difference determination) is avoided, and the subsequent difference determination is performed. The reference value is updated in preparation for (# 12, 1
7).
【００２０】すなわち、検出値Ｖｉｎを取り込む毎に、
新たな基準値Ｖｂａｓｅとして、その時点の基準値Ｖｂ
ａｓｅと、取り込んだ検出値Ｖｉｎとの平均値を設定す
る。なお、基準値Ｖｂａｓｅの初期値としては、連系開
始時の初期化処理において、例えば零が設定される。That is, each time the detected value Vin is fetched,
As a new reference value Vbase, the reference value Vb at that time
The average value of the as and the captured detection value Vin is set. The initial value of the reference value Vbase is set to, for example, zero in the initialization process at the start of interconnection.
【００２１】インバータ回路２１の起動からの経過時間
が１秒を越えると、その後は検出値Ｖｉｎを取り込む毎
に差分判定を行う（＃１３）。差分判定は、単位時間当
たりの変化量ΔＶとして、新たに取り込んだ検出値Ｖｉ
ｎと基準値Ｖｂａｓｅとの差を求め、変化量ΔＶが所定
の閾値Ｖｔｈを越えるか否かを調べる処理である。閾値
Ｖｔｈとしては、例えば商用電力系統２の基準電圧が１
０１Ｖ（実効値）の場合、連系点での電圧レベルに換算
して０．７〜１Ｖ程度の値が選定される。When the elapsed time from the start-up of the inverter circuit 21 exceeds 1 second, thereafter, the difference judgment is made every time the detection value Vin is fetched (# 13). The difference determination is performed by setting the change amount ΔV per unit time as the newly acquired detection value Vi.
This is a process of obtaining the difference between n and the reference value Vbase, and checking whether or not the amount of change ΔV exceeds a predetermined threshold value Vth. As the threshold value Vth, for example, the reference voltage of the commercial power system 2 is 1
In the case of 01 V (effective value), a value of about 0.7 to 1 V is selected in terms of the voltage level at the interconnection point.
【００２２】変化量ΔＶ（＝Ｖｉｎ−Ｖｂａｓｅ）が閾
値Ｖｔｈを越えない場合は、次回の差分判定に備えて基
準値Ｖｂａｓｅの更新を行う（＃１９）。ただし、従来
のように今回の判定対象の検出値Ｖｉｎをそのまま基準
値Ｖｂａｓｅとして設定するのではなく、次回の差分判
定の基準値Ｖｂａｓｅとして、検出値Ｖｉｎと現時点の
基準値Ｖｂａｓｅとの荷重平均値を設定する。このと
き、現時点の基準値Ｖｂａｓｅの重み付けを、検出値Ｖ
ｉｎよりも大きい値（例えば数倍程度）とする。When the variation ΔV (= Vin-Vbase) does not exceed the threshold value Vth, the reference value Vbase is updated in preparation for the next difference judgment (# 19). However, instead of setting the detection value Vin of the present determination target as the reference value Vbase as it is as in the past, the weighted average value of the detection value Vin and the reference value Vbase at the present time is set as the reference value Vbase of the next difference determination. To set. At this time, the weighting of the reference value Vbase at the present time is set to the detected value Vbase.
The value is larger than in (for example, about several times).
【００２３】このように荷重平均値を基準値Ｖｂａｓｅ
とすることにより、基準値Ｖｂａｓｅが、ノイズの無い
理想状態における第３高調波成分の値に近い値となり、
次回の検出で得られた検出値Ｖｉｎに対して適正な差分
判定を行うことができる。In this way, the weighted average value is used as the reference value Vbase.
As a result, the reference value Vbase becomes a value close to the value of the third harmonic component in an ideal state without noise,
Appropriate difference determination can be performed on the detected value Vin obtained in the next detection.
【００２４】一方、第３高調波成分が急増し、ステップ
＃１３の差分判定において変化量ΔＶが閾値Ｖｔｈを越
えた場合には、時限タイマとして設けたダウンカウンタ
による一定時間Ｔの計時を進める（＃１４）。すなわち
時限タイマの更新（デクリメント）を行う。On the other hand, when the third harmonic component rapidly increases and the change amount ΔV exceeds the threshold value Vth in the difference determination in step # 13, the down counter provided as the time limit timer counts the fixed time T (( # 14). That is, the timed timer is updated (decremented).
【００２５】ここで、一定時間Ｔは、例えば０．４ｓで
あり、第３高調波成分の検出周期である５０ｍｓより十
分に長く、且つ商用電力系統２の運用で規定されている
受動的停電検出の反応時間（例えば０．５ｓ）より短い
時間である。なお、時限タイマについては、第３高調波
成分の急増がない平常時において、第３高調波成分の検
出毎に初期化が行われる（＃１８，２０）。Here, the fixed time T is, for example, 0.4 s, which is sufficiently longer than the detection cycle of the third harmonic component of 50 ms, and the passive power failure detection which is defined in the operation of the commercial power system 2 is performed. The reaction time is shorter than the reaction time (for example, 0.5 s). Note that the time limit timer is initialized each time the third harmonic component is detected during normal times when there is no sudden increase in the third harmonic component (# 18, 20).
【００２６】一定時間Ｔの計時中において、ＣＰＵは、
第３高調波成分の検出及び差分判定を繰り返し実行する
（＃１５，１１〜１４）。その際、変化量ΔＶが閾値Ｖ
ｔｈ以下とならない限り、最初に第３高調波成分の急増
を検出した時点の基準値Ｖｂａｓｅを保持する。変化量
ΔＶが閾値Ｖｔｈ以下となった場合は、上述のように荷
重平均演算によって基準値Ｖｂａｓｅを更新して時限タ
イマを初期化する。During counting of the fixed time T, the CPU
The detection of the third harmonic component and the difference determination are repeatedly executed (# 15, 11-14). At that time, the change amount ΔV is equal to the threshold value V
Unless it becomes th or less, the reference value Vbase at the time when the rapid increase of the third harmonic component is first detected is held. When the amount of change ΔV becomes equal to or less than the threshold value Vth, the reference value Vbase is updated by the weighted average calculation as described above, and the timed timer is initialized.
【００２７】そして、ＣＰＵは、変化量ΔＶが閾値Ｖｔ
ｈを越える状態が一定時間Ｔにわたって連続した場合、
つまり、同一の基準値Ｖｂａｓｅに基づく連続した複数
回の差分判定で同様の結果が得られた場合に、系統停電
に起因する第３高調波成分の急増を示す単独運転検出フ
ラグをセットする（＃１６）。Then, the CPU determines that the change amount ΔV is the threshold value Vt.
When the state of exceeding h continues for a certain time T,
In other words, when the same result is obtained by consecutively performing the difference determinations based on the same reference value Vbase, the islanding operation detection flag indicating the rapid increase of the third harmonic component due to the system power failure is set (# 16).
【００２８】以上の単独運転検出処理において単独運転
検出フラグがセットされると、ＣＰＵが実行する他のサ
ブルーチンである出力処理において、単独運転状態を検
出したことを示す単独運転検出信号ＳＤが、マイクロコ
ンピュータ４５の出力ポートから開閉装置３０へ出力さ
れる。When the islanding operation detection flag is set in the above islanding operation detection process, the islanding operation detection signal SD indicating that the islanding operation state is detected in the output process which is another sub-routine executed by the CPU is It is output from the output port of the computer 45 to the switching device 30.
【００２９】開閉装置３０は、単独運転検出信号ＳＤに
呼応して作動し、インバータ２０と商用電力系統２との
連系を解除する。これにより太陽光発電システム１が商
用電力系統２から解列される。The switchgear 30 operates in response to the islanding operation detection signal SD to release the interconnection between the inverter 20 and the commercial power system 2. As a result, the solar power generation system 1 is disconnected from the commercial power system 2.
【００３０】上述の実施例によれば、一定時間Ｔにわた
って第３高調波成分の高レベル状態が持続したときに、
単独運転検出信号ＳＤを出力するようにしたので、１回
の第３高調波成分の急増に呼応して単独運転検出信号Ｓ
Ｄを出力する場合に比べて、検出の信頼性を高めること
ができる。According to the above-mentioned embodiment, when the high level state of the third harmonic component continues for a certain time T,
Since the islanding operation detection signal SD is output, the islanding operation detection signal S is generated in response to one sudden increase in the third harmonic component.
The reliability of detection can be improved as compared with the case of outputting D.
【００３１】上述の実施例において、荷重平均の重み付
けは、ノイズの発生状況などに応じて最適化することが
できる。また、単独運転検出装置４０の回路構成、及び
単独運転検出処理の内容については、種々の変更が可能
である。In the above embodiment, the weighting of the weighted average can be optimized in accordance with the noise occurrence situation. Further, various changes can be made to the circuit configuration of the islanding operation detection device 40 and the content of the islanding operation detection process.
【００３２】なお、本発明は、燃料電池などの太陽電池
以外の直流電源を備えた分散電源設備の単独運転検出に
も適用することができる。The present invention can also be applied to detection of isolated operation of a distributed power supply facility equipped with a DC power supply other than a solar cell such as a fuel cell.
【００３３】[0033]
【発明の効果】本発明によれば、ノイズの影響を軽減す
ることができ、高精度の検出を実現することができる。According to the present invention, the influence of noise can be reduced, and highly accurate detection can be realized.
【００３４】請求項３の発明によれば、より確実な単独
運転検出を実現することができる。According to the third aspect of the present invention, more reliable isolated operation detection can be realized.
【図１】本発明を適用した単独運転検出装置を有する太
陽光発電システムのブロック図である。FIG. 1 is a block diagram of a photovoltaic power generation system having an islanding operation detection device to which the present invention is applied.
【図２】単独運転検出処理のフローチャートである。FIG. 2 is a flowchart of islanding operation detection processing.
【図３】本発明に係る差分判定の基準値の推移の一例を
示す図である。FIG. 3 is a diagram showing an example of transition of a reference value for difference determination according to the present invention.
【図４】従来の検出方法を示す図である。FIG. 4 is a diagram showing a conventional detection method.
２ 商用電力系統 ２０ インバータ Ｖ 連系点の電圧 Ｖｉｎ 検出値 Ｖｂａｓｅ 基準値 ΔＶ 変化量（差） Ｖｔｈ 閾値 ＳＤ 単独運転検出信号（検出信号） 2 Commercial power system 20 Inverter V Voltage at interconnection point Vin Detected value Vbase Reference value ΔV Change amount (difference) Vth threshold SD Independent operation detection signal (detection signal)
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０２Ｊ 7/35 Ｋ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI technical display area H02J 7/35 K
Claims (3)
との連系点における電圧の第３高調波成分を検出すると
ともに、その検出値と基準値との差を求めて閾値と比較
する差分判定を行うことにより、前記第３高調波成分の
急増を検出する単独運転検出方法であって、 各回の差分判定において前記検出値と基準値との差が前
記閾値を越えない場合には、次回の差分判定の基準値と
して前記検出値と現時点の基準値との荷重平均値を設定
することを特徴とする単独運転検出方法。1. A difference for detecting a third harmonic component of a voltage at a connection point between an inverter and a commercial power system at a constant cycle, obtaining a difference between the detected value and a reference value, and comparing the difference with a threshold value. A method for detecting an isolated operation in which a rapid increase in the third harmonic component is detected by making a determination, and when the difference between the detected value and the reference value does not exceed the threshold value in each difference determination, Is set as a reference value for the difference judgment of the above-mentioned detection value and a reference value at the present time.
点の基準値の重み付けを、前記検出値の重み付けよりも
大きくすることを特徴とする請求項１記載の単独運転検
出方法。2. The islanding operation detection method according to claim 1, wherein, when setting the weighted average value, the weighting of the reference value at the present time is made larger than the weighting of the detection value.
えた場合には、前記現時点の基準値を保持した状態で、
前記第３高調波成分の検出及びその後の差分判定を行
い、一定時間にわたって検出値と基準値との差が連続し
て前記閾値を越えたときに、前記第３高調波成分の急増
を示す検出信号を発することを特徴とする請求項１又は
請求項２記載の単独運転検出方法。3. When the difference between the detected value and the reference value exceeds the threshold value, the reference value at the present time is held,
The detection of the third harmonic component and the subsequent difference determination are performed, and when the difference between the detected value and the reference value continuously exceeds the threshold value for a certain period of time, the detection indicating the rapid increase of the third harmonic component is detected. The islanding operation detection method according to claim 1 or 2, wherein a signal is emitted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29617393A JP3448325B2 (en) | 1993-11-26 | 1993-11-26 | Islanding detection method for distributed power supply equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29617393A JP3448325B2 (en) | 1993-11-26 | 1993-11-26 | Islanding detection method for distributed power supply equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07154920A true JPH07154920A (en) | 1995-06-16 |
| JP3448325B2 JP3448325B2 (en) | 2003-09-22 |
Family
ID=17830110
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29617393A Expired - Fee Related JP3448325B2 (en) | 1993-11-26 | 1993-11-26 | Islanding detection method for distributed power supply equipment |
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| Country | Link |
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| JP (1) | JP3448325B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008035619A (en) * | 2006-07-28 | 2008-02-14 | Omron Corp | Determination method for individual operation of dispersed power system |
| JP2010038787A (en) * | 2008-08-06 | 2010-02-18 | Midori Anzen Co Ltd | Insulation monitoring device |
| JP2010074943A (en) * | 2008-09-18 | 2010-04-02 | Kansai Electric Power Co Inc:The | Method and device for detecting individual operation |
| CN102130467A (en) * | 2010-01-19 | 2011-07-20 | 通用电气公司 | Open circuit voltage protection system and method |
| JP2014117016A (en) * | 2012-12-06 | 2014-06-26 | Panasonic Corp | Single operation detection device and method, power conditioner and distributed power source system |
| JP2015061417A (en) * | 2013-09-19 | 2015-03-30 | 積水化学工業株式会社 | Energy management system |
| JP2019193318A (en) * | 2018-04-18 | 2019-10-31 | 新電元工業株式会社 | Harmonic measuring apparatus and individual operation detecting method using the same, individual operation detecting apparatus and distributed power supply system |
-
1993
- 1993-11-26 JP JP29617393A patent/JP3448325B2/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008035619A (en) * | 2006-07-28 | 2008-02-14 | Omron Corp | Determination method for individual operation of dispersed power system |
| JP2010038787A (en) * | 2008-08-06 | 2010-02-18 | Midori Anzen Co Ltd | Insulation monitoring device |
| JP2010074943A (en) * | 2008-09-18 | 2010-04-02 | Kansai Electric Power Co Inc:The | Method and device for detecting individual operation |
| CN102130467A (en) * | 2010-01-19 | 2011-07-20 | 通用电气公司 | Open circuit voltage protection system and method |
| JP2014117016A (en) * | 2012-12-06 | 2014-06-26 | Panasonic Corp | Single operation detection device and method, power conditioner and distributed power source system |
| JP2015061417A (en) * | 2013-09-19 | 2015-03-30 | 積水化学工業株式会社 | Energy management system |
| JP2019193318A (en) * | 2018-04-18 | 2019-10-31 | 新電元工業株式会社 | Harmonic measuring apparatus and individual operation detecting method using the same, individual operation detecting apparatus and distributed power supply system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3448325B2 (en) | 2003-09-22 |
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