JP2001268802A - System connection protection method and device of distributed power supply - Google Patents
System connection protection method and device of distributed power supplyInfo
- Publication number
- JP2001268802A JP2001268802A JP2000076236A JP2000076236A JP2001268802A JP 2001268802 A JP2001268802 A JP 2001268802A JP 2000076236 A JP2000076236 A JP 2000076236A JP 2000076236 A JP2000076236 A JP 2000076236A JP 2001268802 A JP2001268802 A JP 2001268802A
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- Prior art keywords
- frequency
- power supply
- voltage
- distributed power
- cycle
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、太陽光発電、燃
料電池発電、風力発電、マイクロタービン発電などの直
流電力又は交流電力をインバータやサイクロコンバータ
などで商用周波数の交流電力に変換して負荷に供給する
と共に、交流電力系統に連系して運転する分散型電源の
系統連系保護方法およびその装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of converting DC power or AC power of photovoltaic power generation, fuel cell power generation, wind power generation, microturbine power generation or the like into AC power of a commercial frequency by an inverter or a cycloconverter, and applying the converted power to a load. The present invention relates to a system interconnection protection method and apparatus for a distributed power supply that operates while being connected to an AC power system.
【０００２】[0002]
【従来の技術】図５は、例えば特許第２７９６０３５号
公報に示された従来の保護方法およびその装置を示すブ
ロック図であり、図において、１は太陽電池あるいは燃
料電池等からなる直流電源で、インバータブリッジ２に
より交流電力に変換され、この交流電力はリアクトル３
とコンデンサ４からなるフィルタによりＰＷＭ(パルス
幅変調)制御にて発生する高調波分が除去されて負荷９
に供給される。2. Description of the Related Art FIG. 5 is a block diagram showing a conventional protection method and its device disclosed in, for example, Japanese Patent No. 2796035. In the drawing, reference numeral 1 denotes a DC power supply composed of a solar cell or a fuel cell. The AC power is converted into AC power by the inverter bridge 2, and this AC power is
And a capacitor 4 removes harmonic components generated by PWM (pulse width modulation) control, and
Supplied to
【０００３】一方、交流電力系統８からしゃ断器７と変
圧器６を介して供給される一般家庭用の交流電力が負荷
９に供給されており、インバータブリッジ２の交流電力
は交流電力系統８に連系して運転する。負荷９に供給さ
れる交流電圧は、電圧検出器１０によって検出され、直
流電源１の電圧Ｖを電圧指令Ｖ*に合致するように制御
する増幅器１１の出力Ｖｃと、周波数検出回路２２や歪
検出器２７等の情報をもとに３１の位相ゲイン設定回路
にて設定された振幅のゲインＧと位相θと、により電流
基準回路１２にて電流指令Ｉ*が生成され、この電流指
令Ｉ*と電流検出器５で検出したインバータブリッジ２
の出力電流Ｉが増幅器１３に入力され、ＰＷＭ制御部１
４、駆動部１５を介して電流偏差が零になるようにイン
バータブリッジ２をＰＷＭ制御する。On the other hand, AC power for ordinary households supplied from an AC power system 8 via a circuit breaker 7 and a transformer 6 is supplied to a load 9, and the AC power of the inverter bridge 2 is supplied to the AC power system 8. Connect and drive. The AC voltage supplied to the load 9 is detected by a voltage detector 10, the output Vc of the amplifier 11 for controlling the voltage V of the DC power supply 1 so as to match the voltage command V *, the frequency detection circuit 22, and the distortion detection. The current reference circuit 12 generates a current command I * based on the gain G and the phase θ of the amplitude set by the phase gain setting circuit 31 based on the information of the detector 27 and the like. Inverter bridge 2 detected by current detector 5
Is output to the amplifier 13 and the PWM control unit 1
4. PWM control of the inverter bridge 2 via the drive unit 15 so that the current deviation becomes zero.
【０００４】電流基準Ｉ*の位相は、負荷９に供給され
る交流電圧の位相にほぼ一致しており、インバータブリ
ッジ２から高力率の交流電力が供給される。The phase of the current reference I * substantially coincides with the phase of the AC voltage supplied to the load 9, and a high power factor AC power is supplied from the inverter bridge 2.
【０００５】このような配電系統において、変圧器６を
含む負荷側の保守点検を行う場合、遮断機７を開放して
交流電源系統８から切り離して行われる。分散型電源が
交流電力系統８から切り離された後も運転を続けている
状態を単独運転と呼び保守点検を行うとき危険であるた
め、素早く確実に単独運転を検出して運転を停止する必
要がある。[0005] In such a distribution system, when performing maintenance and inspection on the load side including the transformer 6, the circuit breaker 7 is opened and separated from the AC power supply system 8. A state in which the distributed power source is continued to operate even after being disconnected from the AC power system 8 is referred to as an isolated operation, which is dangerous when performing maintenance and inspection. Therefore, it is necessary to quickly and surely detect the isolated operation and stop the operation. is there.
【０００６】このとき、インバータブリッジ２から供給
する電力と、負荷９の電力がバランスしていると単独運
転の検出が難しく、この例ではインバータ出力の無効電
力と負荷の無効電力がわずかでもアンバランスしている
時はインバータ出力電圧の周波数がわずかに上昇又は下
降するので周波数ｆと周波数変化率ｄｆ／ｄｔを検出
し、演算回路２４によりｆ＋α(ｄｆ／ｄｔ)(αは係数)
を求め、係数設定回路３０で重みづけをして図６の変数
Ｆ1、Ｆ2を設定し、位相・ゲイン設定回路３１により周
波数が上昇した場合はインバータ電流位相を進ませ、周
波数が更に上昇して発散させ、周波数が下降した場合は
電流位相を遅らせて周波数を下降して発散させ、周波数
が周波数リレー１８に設定されたＦｘ又はＦｙを素早く
超えて単独運転を短時間に検出する工夫がなされてい
る。At this time, if the power supplied from the inverter bridge 2 and the power of the load 9 are balanced, it is difficult to detect the islanding operation. In this example, the reactive power of the inverter output and the reactive power of the load are unbalanced even if they are slight. In this case, the frequency of the inverter output voltage slightly increases or decreases, so that the frequency f and the frequency change rate df / dt are detected, and the arithmetic circuit 24 calculates f + α (df / dt) (α is a coefficient).
And weights are set by the coefficient setting circuit 30 to set the variables F 1 and F 2 in FIG. 6. If the frequency is increased by the phase / gain setting circuit 31, the inverter current phase is advanced to further increase the frequency. When the frequency drops, the current phase is delayed to lower the frequency to diverge, and the frequency quickly exceeds Fx or Fy set in the frequency relay 18 to detect the isolated operation in a short time. It has been done.
【０００７】また、電力の有効分及び無効分が完全にバ
ランスしている時は電圧、周波数共に変化しないので、
図７に示すように変圧器６の交流電圧のゼロクロス付近
で鉄心の飽和特性により励磁電流ｉｅｘが正弦波から歪
むことによる電圧波形ＶACのゼロクロス付近の歪の増大
を歪検出回路２７、歪変化検出回路３３で検出し、単独
運転の可能性を検出して、図６のゲイン特性の横軸Ｆ1
と位相特性横軸Ｆ2をシフトし電力のバランスをくずし
て周波数と電圧を変動させ電圧リレー１７、周波数リレ
ー１８でインバータブリッジ２の運転を停止させるよう
にしている。Further, when the effective component and the reactive component of the power are completely balanced, the voltage and the frequency do not change.
Distortion detecting circuit 27 excitation current iex by saturation characteristics of the iron core in the vicinity of zero cross of the AC voltage is increased distortion near the zero crossing of the voltage waveform V AC by being distorted from the sine wave of the transformer 6 as shown in FIG. 7, the distortion change detected by the detection circuit 33 detects a possibility of independent operation, the horizontal axis F 1 of the gain characteristics of Fig. 6
A phase characteristic horizontal axis F 2 shifts the voltage relay 17 varies the frequency and voltage of balance of power, and so as to stop the operation of the inverter bridge 2 in the frequency relay 18.
【０００８】[0008]
【発明が解決しようとする課題】従来の分散型電源の系
統連系保護方法およびその装置は以上のように周波数の
変化で電流位相を変えているが、その位相を変えるタイ
ミングをいずれの位相に選んでも位相跳躍が発生し、又
その結果出力電流に直流分が発生してしまい負荷及び変
圧器にとっては好ましくない。As described above, the conventional method and the apparatus for protecting the interconnection of the distributed power supply system change the current phase by changing the frequency, but the timing of changing the phase is changed to any phase. Even if it is selected, a phase jump occurs, and as a result, a DC component is generated in the output current, which is not preferable for the load and the transformer.
【０００９】更に、電力の有効分及び無効分が完全にバ
ランスして単独運転になったとき電圧波形のゼロクロス
付近に発生する歪の増大は変圧器の特性によってまちま
ちで歪リレーの閾値の選び方が難しく、又、同一変圧器
に２台以上の分散型電源が接続されていると変圧器に近
い方の分散型電源が励磁電流を供給してしまって、下流
の分散型電源にはその歪が発生しにくく検出できなくな
る可能性があるなどの問題があった。Further, when the effective component and the reactive component of the power are completely balanced and the isolated operation is performed, the increase in the distortion generated near the zero cross of the voltage waveform varies depending on the characteristics of the transformer. It is difficult, and if two or more distributed power sources are connected to the same transformer, the distributed power source closer to the transformer will supply the exciting current, and the downstream distributed power source will be distorted. There is a problem that it is unlikely to occur and the detection may not be possible.
【００１０】この発明は上記のような問題点を解消する
ためになされたもので、単独運転検出のために位相跳躍
や出力電流の直流分が増加することもなく、また変圧器
の特性や同一変圧器に接続されている分散型電源の台数
に関係なく短時間に確実に単独運転検出することができ
る分散型電源の系統連系保護方法およびその装置を提供
することを目的とする。SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and there is no phase jump and no increase in the DC component of the output current due to islanding operation detection. It is an object of the present invention to provide a method and apparatus for protecting a grid connection of a distributed power supply that can reliably detect islanding operation in a short time regardless of the number of distributed power supplies connected to a transformer.
【００１１】[0011]
【課題を解決するための手段】上記の目的に鑑み、この
発明は、発電電力を交流電力に変換し交流電力系統と連
系して運転する分散型電源において、前記交流電力系統
及び前記分散型電源の出力の電圧位相に同期し所定の位
相で出力する電流指令に合致するように前記分散型電源
の出力電流の制御を行い、前記電圧の周波数の変化量を
所定関数演算した分を現在又はそれ以前の電流指令又は
電圧の周波数に加えたものを新たな電流指令の周波数と
することを特徴とする分散型電源の系統連系保護方法に
ある。SUMMARY OF THE INVENTION In view of the above object, the present invention relates to a distributed power supply that converts generated power into AC power and operates in connection with an AC power system. The output current of the distributed power supply is controlled so as to match a current command output at a predetermined phase in synchronization with the voltage phase of the output of the power supply, and the amount of change in the frequency of the voltage is calculated by a predetermined function. A method for protecting a system connection of a distributed power supply, characterized in that a frequency of a current command or a voltage added to a frequency of a previous current command is set as a new frequency of a current command.
【００１２】また、発電電力を交流電力に変換し交流電
力系統と連系して運転する分散型電源において、前記交
流電力系統及び前記分散型電源の出力の電圧位相に同期
し所定の位相で出力する電流指令に合致するように前記
分散型電源の出力電流の制御を行い、前記電圧の周期の
変化量を所定関数演算した分を現在又はそれ以前の電流
指令又は電圧の周期に加えたものを新たな電流指令の周
期とすることを特徴とする分散型電源の系統連系保護方
法にある。In a distributed power supply that converts generated power into AC power and operates in connection with an AC power system, an output at a predetermined phase synchronized with a voltage phase of an output of the AC power system and the distributed power supply. The output current of the distributed power supply is controlled so as to match the current command to be performed, and the amount obtained by performing a predetermined function operation on the amount of change in the voltage cycle is added to the current or previous current command or voltage cycle. A method for protecting a system interconnection of a distributed power supply characterized by a new current command cycle is provided.
【００１３】また、電圧の所定位相間に発生した既知の
周期を有する基準クロックのクロック数をディジタル計
数して電圧の周期を計測することを特徴とする請求項２
に記載の分散型電源の系統連系保護方法にある。Further, the voltage cycle is measured by digitally counting the number of reference clocks having a known cycle generated during a predetermined phase of the voltage.
In the method for protecting the grid connection of the distributed power supply described in (1).
【００１４】また、電圧の周波数又は周期が所定範囲を
超えた延べ時間が所定時間内に所定時間以上、または周
波数又は周期が所定範囲を超えた回数が所定時間内に所
定回数以上発生したとき、単独運転と判断することを特
徴とする請求項１ないし３のいずれかに記載の分散型電
源の系統連系保護方法にある。When the total time when the frequency or cycle of the voltage exceeds the predetermined range exceeds a predetermined time within the predetermined time, or when the number of times when the frequency or cycle exceeds the predetermined range occurs more than the predetermined number within the predetermined time, The method according to any one of claims 1 to 3, wherein the operation is determined to be an isolated operation.
【００１５】また、電流指令の周波数又は周期の変更は
電流指令又は出力電流のゼロクロスにて行うことを特徴
とする請求項１ないし４のいずれかに記載の分散型電源
の系統連系保護方法にある。5. The method according to claim 1, wherein the frequency or cycle of the current command is changed at a zero crossing of the current command or the output current. is there.
【００１６】また、発電電力を交流電力に変換し交流電
力系統と連系して運転する分散型電源において、負荷に
供給される交流電圧の周波数を検出する周波数検出手段
と、前記電圧の周波数の変化量を所定関数演算した分
を、現在又はそれ以前の電流指令又は電圧の周波数に加
えたものを新たな電流指令の周波数として求める電流指
令周波数演算手段と、前記交流電力系統及び前記分散型
電源の出力の電圧位相に同期し所定の位相で出力する前
記周波数の電流指令に合致するように前記分散型電源の
出力電流の制御を行う分散型電源出力電流制御手段と、
を備えたことを特徴とする分散型電源の系統連系保護装
置にある。Further, in a distributed power supply that converts generated power into AC power and operates in connection with an AC power system, frequency detection means for detecting a frequency of an AC voltage supplied to a load; Current command frequency calculating means for obtaining a value obtained by adding a value obtained by performing a predetermined function calculation of the amount of change to a current or previous current command or voltage frequency as a new current command frequency; and the AC power system and the distributed power supply. Distributed power supply output current control means for controlling the output current of the distributed power supply so as to match the current command of the frequency to be output at a predetermined phase in synchronization with the voltage phase of the output,
And a system interconnection protection device for a distributed power supply.
【００１７】また、発電電力を交流電力に変換し交流電
力系統と連系して運転する分散型電源において、負荷に
供給される交流電圧の周期を検出する周期検出手段と、
前記電圧の周期の変化量を所定関数演算した分を、現在
又はそれ以前の電流指令又は電圧の周期に加えたものを
新たな電流指令の周期として求める電流指令周期演算手
段と、前記交流電力系統及び前記分散型電源の出力の電
圧位相に同期し所定の位相で出力する前記周期の電流指
令に合致するように前記分散型電源の出力電流の制御を
行う分散型電源出力電流制御手段と、を備えたことを特
徴とする分散型電源の系統連系保護装置にある。Further, in a distributed power supply that converts generated power into AC power and operates in connection with an AC power system, cycle detection means for detecting a cycle of the AC voltage supplied to the load;
Current command cycle calculating means for obtaining a value obtained by adding the amount of change of the voltage cycle by a predetermined function to a current or previous cycle of the current command or voltage as a new current command cycle; and And a distributed power supply output current control means for controlling the output current of the distributed power supply so as to match the current command of the cycle synchronized with the voltage phase of the output of the distributed power supply and output at a predetermined phase. A system interconnection protection device for a distributed power supply, comprising:
【００１８】また、前記周期検出手段が、電圧の所定位
相間に発生した既知の周期を有する基準クロック数をデ
ジタル計数して電圧の周期を計測することを特徴とする
請求項７に記載の分散型電源の系統連系保護装置にあ
る。8. The dispersion according to claim 7, wherein said period detecting means digitally counts the number of reference clocks having a known period generated during a predetermined phase of the voltage to measure the period of the voltage. It is in the system interconnection protection device of the type power supply.
【００１９】また、電圧の周波数又は周期が所定範囲を
超えた延べ時間が所定時間内に所定時間以上、または周
波数又は周期が所定範囲を超えた回数が所定時間内に所
定回数以上発生したとき、単独運転と判断する単独運転
判定手段をさらに備えたことを特徴とする請求項６ない
し８のいずれかに記載の分散型電源の系統連系保護装置
にある。When the total time when the frequency or cycle of the voltage exceeds the predetermined range exceeds a predetermined time within the predetermined time, or when the number of times when the frequency or cycle exceeds the predetermined range occurs more than the predetermined number within the predetermined time, The system interconnection protection device for a distributed power supply according to any one of claims 6 to 8, further comprising an islanding operation determining means for determining an islanding operation.
【００２０】また、前記分散型電源出力電流制御手段に
おいて、電流指令の周波数又は周期の変更は電流指令又
は出力電流のゼロクロスにて行うことを特徴とする請求
項６ないし９のいずれかに記載の分散型電源の系統連系
保護装置にある。10. The method according to claim 6, wherein in the distributed power supply output current control means, the frequency or cycle of the current command is changed at a zero crossing of the current command or the output current. It is in the system interconnection protection device of the distributed power supply.
【００２１】[0021]
【発明の実施の形態】以下、この発明の各実施の形態を
図に従って説明する。 実施の形態１．図１はこの発明の一実施の形態による分
散型電源の系統連系保護方法およびその装置を示す制御
ブロック図である。図中、従来のものと同一符号で示さ
れているものは同一もしくは相当部分を示し、説明は省
略する。Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a control block diagram showing a system interconnection protection method and apparatus for a distributed power supply according to an embodiment of the present invention. In the figure, components denoted by the same reference numerals as those of the conventional device indicate the same or corresponding portions, and description thereof is omitted.
【００２２】本図で用いる電流基準回路１２は増幅器１
１の出力電圧Ｖｃと系統電圧Ｖａに応じて振幅が変化
し、周波数検出回路２２にて検出された系統電圧周波数
ｆとその変化量ｄｆ／ｄｔを所定関数演算したＦ(ｄｆ
／ｄｔ)((１)式による)した分を加算した周波数ｆ*(＝
ｆ＋Ｆ(ｄｆ／ｄｔ))を周波数とする電流指令Ｉａ*を出
力し、増幅器１３により系統に流出される電流Ｉａが電
流指令Ｉａ*と合致するように制御する。The current reference circuit 12 used in FIG.
The amplitude changes in accordance with the output voltage Vc of 1 and the system voltage Va, and the system voltage frequency f detected by the frequency detection circuit 22 and the amount of change df / dt are calculated by a predetermined function F (df
/ Dt) (according to equation (1)), the frequency f * (=
A current command Ia * having a frequency of f + F (df / dt)) is output, and control is performed so that the current Ia flowing into the system by the amplifier 13 matches the current command Ia *.
【００２３】[0023]
【数１】 (Equation 1)
【００２４】一方、電圧リレー１７は電圧検出器１０で
検出した系統電圧Ｖａと設定電圧値と比較して交流電圧
の異常を検出し、これを異常検出回路１９に入力する。On the other hand, the voltage relay 17 detects an abnormality in the AC voltage by comparing the system voltage Va detected by the voltage detector 10 with the set voltage value, and inputs this to the abnormality detection circuit 19.
【００２５】また、周波数検出回路２２で検出された周
波数ｆは周波数リレー１８にも入力され、ここで系統電
圧周波数の異常を検出し、これを異常検出回路１９に入
力する。Further, the frequency f detected by the frequency detection circuit 22 is also input to the frequency relay 18, where an abnormality in the system voltage frequency is detected, and this is input to the abnormality detection circuit 19.
【００２６】以下、このように構成された本発明の実施
の形態の動作について説明する。Hereinafter, the operation of the embodiment of the present invention configured as described above will be described.
【００２７】今、負荷９を簡略化のため一般に行われて
いるように図１に示すようなＬＲＣ並列負荷で説明す
る。負荷電流ＩLと負荷電圧Ｖａとの関係式は定常状態
にて(２)式のようになる。Now, the load 9 will be described with an LRC parallel load as shown in FIG. 1 as generally performed for simplification. Relationship between the load current I L and the load voltage Va is as at steady state (2).
【００２８】[0028]
【数２】 (Equation 2)
【００２９】負荷電流ＩLを入力、負荷電圧Ｖａを出力
とする位相特性曲線は、(１)式から例えば図２のように
なる。この図は負荷の固有周波数(１／２π√(ＬＣ))が
６０Ｈｚより低い場合を示している。この図において６
０Ｈｚの交流電力系統に接続されている場合のこの分散
型電源の動作点は周波数が６０Ｈｚ、位相が０°であ
り、この状態で遮断器７が開放され交流電力系統８から
切り離されると、Ｉａは直ちには変化しないが、Ｖａの
位相は直ちに負荷の特性曲線に接近しようとして遅れ
る。このことはＶａの周波数が直ちに降下することを意
味する。すると元々ＩａはＶａと同相になるように制御
されているので、Ｉａの周波数も降下しようとする。[0029] Enter the load current I L, the phase characteristic curve to output the load voltage Va is as shown in FIG. 2, for example from (1). This figure shows the case where the natural frequency (1 / 2π√ (LC)) of the load is lower than 60 Hz. In this figure, 6
When connected to a 0 Hz AC power system, the operating point of this distributed power supply has a frequency of 60 Hz and a phase of 0 °. When the circuit breaker 7 is opened and disconnected from the AC power system 8 in this state, Ia Does not change immediately, but the phase of Va lags immediately trying to approach the characteristic curve of the load. This means that the frequency of Va drops immediately. Then, since Ia is originally controlled to be in phase with Va, the frequency of Ia also tends to drop.
【００３０】このとき、Ｉａの周波数変化がＶａの周波
数変化に比べて大きくなるようにＶａの周波数の変化量
ｄｆ／ｄｔを所定関数演算したＦ(ｄｆ／ｄｔ)をＶａの
周波数ｆに加えたものを電流指令Ｉａ*の周波数ｆ*とし
ているので(変化量検出回路２３、関数演算器２３ａ、
加算器２３ｂの部分参照)、Ｖａの周波数は加速度的に
降下し、周波数リレー１８で単独運転を検出することが
できる。At this time, F (df / dt) obtained by performing a predetermined function operation of the variation df / dt of the frequency of Va so as to make the frequency variation of Ia larger than the frequency variation of Va is added to the frequency f of Va. Is set as the frequency f * of the current command Ia * (the change amount detection circuit 23, the function calculator 23a,
The frequency of Va drops at an accelerated rate, and the isolated operation can be detected by the frequency relay 18.
【００３１】負荷の固有周波数が交流電力系統の周波数
よりも高いときには、Ｖａの周波数は加速度的に上昇
し、周波数リレー１８で単独運転を検出することができ
る。When the natural frequency of the load is higher than the frequency of the AC power system, the frequency of Va increases at an accelerated rate, and the isolated operation can be detected by the frequency relay 18.
【００３２】また、負荷の固有周波数が系統周波数と一
致している場合にも交流電力系統としゃ断されれば、検
出器や制御系のノイズとしての外乱でＶａの周波数は発
散し、周波数リレー１８で単独運転を検出することがで
きる。Further, even when the natural frequency of the load coincides with the system frequency, if the AC power system is cut off, the frequency of Va diverges due to disturbance as noise in the detector and the control system, and the frequency relay 18 Can detect the islanding operation.
【００３３】尚、交流電力系統に連系されている場合に
は交流電力系統のインピーダンスが分散型電源の出力イ
ンピーダンスに比べてかなり小さいので、たとえ電流Ｉ
ａの周波数を交流電力系統の周波数と異なって与えても
系統電圧Ｖａの周波数は全くといっていいほど変化しな
いので正常時に単独運転を誤検出することはない。When the AC power system is connected to the AC power system, the impedance of the AC power system is considerably smaller than the output impedance of the distributed power supply.
Even if the frequency a is given differently from the frequency of the AC power system, the frequency of the system voltage Va does not substantially change at all, so that the single operation is not erroneously detected in a normal state.
【００３４】なお、周波数検出手段が電圧検出器１０、
周波数検出回路２２により構成され、電流指令周波数演
算手段が変化量検出回路２３、関数演算器２３ａ、加算
器２３ｂにより構成され、分散型電源出力電流制御手段
が増幅器１１、電流基準回路１２、増幅器１３、ＰＷＭ
制御部１４および駆動部１５により構成される。The frequency detecting means is a voltage detector 10,
The current command frequency calculating means includes a change amount detecting circuit 23, a function calculator 23a, and an adder 23b. The distributed power supply output current controlling means includes an amplifier 11, a current reference circuit 12, and an amplifier 13. , PWM
It is constituted by a control unit 14 and a drive unit 15.
【００３５】実施の形態２．なお、上記実施の形態では
系統電圧周波数を検出して、その周波数に基づいて電流
指令Ｉａ*の周波数を決定する方法を示したが、周波数
の代わりに系統電圧の周期を例えば電圧ゼロクロスなど
で検出してもよく、その場合のこの発明の別の実施の形
態による分散型電源の系統連系保護方法およびその装置
の制御ブロック図を図３に示す。Embodiment 2 In the above embodiment, the method of detecting the system voltage frequency and determining the frequency of the current command Ia * based on the frequency has been described. However, instead of the frequency, the cycle of the system voltage is detected by, for example, voltage zero crossing. FIG. 3 shows a control block diagram of a method for protecting a system interconnection of a distributed power supply and a device thereof according to another embodiment of the present invention in that case.
【００３６】図３において、系統電圧Ｖａの周期を４２
の周期検出回路で検出し、変化量検出回路４３にて前回
の検出周期からの変化量(増加した場合を正とする)△Ｔ
求め、それを所定関数演算したＦ(ΔＴ)((３)式による)
と、今回の周期Ｔとを加えたＴ*＝Ｔ＋Ｆ(ΔＴ)を電流
指令Ｉａ*の周期として与えてやると(変化量検出回路４
３、関数演算器４３ａ、加算器４３ｂの部分参照)、交
流電力系統に連系されている場合には実施の形態１と同
じ理由により系統電圧Ｖａの周期は安定しているが、遮
断器７が開放されて単独運転状態になると系統電圧Ｖａ
の周期は途端に発散し、周期リレー４８にて単独運転を
検出することができる。In FIG. 3, the cycle of the system voltage Va is 42
, And the change amount detection circuit 43 detects the change amount from the previous detection period (the increase is regarded as positive) 正 T
F (ΔT) which is obtained and calculated by a predetermined function (according to equation (3))
T * = T + F (ΔT), which is obtained by adding the current cycle T to the current cycle T, is given as the cycle of the current command Ia *.
3, the function calculator 43a and the adder 43b), and when connected to an AC power system, the cycle of the system voltage Va is stable for the same reason as in the first embodiment. Is released to enter the islanding state, the system voltage Va
The cycle of diverges immediately, and the isolated operation can be detected by the cycle relay 48.
【００３７】[0037]
【数３】 (Equation 3)
【００３８】なお、周期検出手段が電圧検出器１０、周
期検出回路４２により構成され、電流指令周期演算手段
が変化量検出回路４３、関数演算器４３ａ、加算器４３
ｂにより構成され、分散型電源出力電流制御手段が増幅
器１１、電流基準回路１２、増幅器１３、ＰＷＭ制御部
１４および駆動部１５により構成される。The period detecting means comprises the voltage detector 10 and the period detecting circuit 42, and the current command period calculating means comprises the change amount detecting circuit 43, the function calculating unit 43a, and the adder 43.
b, the distributed power supply output current control means includes an amplifier 11, a current reference circuit 12, an amplifier 13, a PWM control unit 14, and a drive unit 15.
【００３９】実施の形態３．尚、上記実施の形態では、
負荷の固有周波数が系統周波数と一致している場合に
は、検出器や制御系のノイズとしての外乱でＶａの周波
数あるいは周期が発散すると述べたが、それを確実に行
う方法を図４を用いて説明する。制御ブロック図は図３
に示した内容になるが、系統電圧Ｖａの周期を検出する
のに周期検出回路４２において例えば外部からの周期が
ｔcの基準クロックＣＬを用いてＶａのゼロクロスから
ゼロクロスまでに発生した基準クロック数をデジタル計
数器(例えば４２ａで示す)で計数し、その数がｎであっ
たならｔc・ｎを電圧Ｖａの周期として検出する。な
お、基準クロック発振器を周期検出回路４２内に設けて
もよい。Embodiment 3 In the above embodiment,
It has been stated that when the natural frequency of the load coincides with the system frequency, the frequency or cycle of Va diverges due to disturbance as noise in the detector and the control system. Will be explained. The control block diagram is shown in FIG.
The cycle detection circuit 42 detects the cycle of the system voltage Va by using, for example, a reference clock CL having an external cycle of tc to determine the number of reference clocks generated from zero crossing of Va to zero crossing. It is counted by a digital counter (for example, indicated by 42a), and if the number is n, tcn is detected as the cycle of the voltage Va. Note that a reference clock oscillator may be provided in the cycle detection circuit 42.
【００４０】すると一般に基準クロックと電力系統とは
同期をとっている訳ではないので、少なくとも±１ビッ
トの電子化誤差が発生する。その電子化誤差分は所定関
数演算で増幅されて電流指令Ｉａ*の周期となるように
制御されるので、単独運転になったらその電子化誤差発
生をきっかけとして、周期が発散し、周期リレー４８に
て単独運転が検出できる。Then, since the reference clock and the power system are not generally synchronized, a digitization error of at least ± 1 bit occurs. Since the digitization error is amplified by a predetermined function operation and controlled so as to become the cycle of the current command Ia *, the cycle diverges due to the occurrence of the digitization error when the isolated operation starts, and the cycle relay 48 Can be used to detect islanding.
【００４１】実施の形態４．又、上記実施の形態では電
流指令Ｉａ*の周波数あるいは周期に対し制限を加えな
かったが、単独運転中にあまり大きくそれらが逸脱する
ことはリアクトル３、コンデンサ４、変圧器６及び負荷
９にとって好ましくない場合があるので、上限及び下限
を設けた方がよい。Embodiment 4 FIG. In the above embodiment, the frequency or cycle of the current command Ia * is not limited. However, it is preferable for the reactor 3, the capacitor 4, the transformer 6, and the load 9 to deviate too much during the isolated operation. Since there may be no case, it is better to set an upper limit and a lower limit.
【００４２】電流指令Ｉａ*の周波数あるいは周期に上
限及び下限の制限を設けた場合、負荷の固有周波数が系
統周波数と一致している条件などで単独運転となった場
合に電圧Ｖａの周波数または周期が周波数あるいは周期
の上限と下限の間を往復するハンチング現象や上限ある
いは下限を少し超えては制限内に復帰し、また少し超え
ては復帰するというのを繰り返すことがある。ここで、
単独運転を検出してからインバータブリッジ２を停止さ
せるタイミングについて少し説明すると、電力系統では
落雷などにより短い瞬時停電が発生することがあるの
で、あまり短い単独運転に対してはインバータブリッジ
２を停止しなくても支障を生じない。When the upper limit and the lower limit are set for the frequency or cycle of the current command Ia *, the frequency or cycle of the voltage Va is set when the isolated operation is performed under the condition that the natural frequency of the load matches the system frequency. In some cases, the hunting phenomenon that reciprocates between the upper limit and the lower limit of the frequency or the cycle, the return to within the limit when the upper limit or the lower limit is slightly exceeded, and the return to the limit when the limit is exceeded slightly may be repeated. here,
The timing of stopping the inverter bridge 2 after detecting the islanding operation will be briefly described. In the power system, a short momentary power failure may occur due to a lightning strike or the like. There is no problem even if it is not.
【００４３】そこで一般には単独運転検出が所定時間続
いた場合にインバータブリッジ２を停止させる処置をと
るが、本発明の場合には周波数または周期の上限あるい
は下限を一端超えたものが制限内に復帰することもあり
得るので、電圧Ｖａの周波数又は周期が所定範囲を超え
た延べ時間が所定時間内に所定時間以上、または、周波
数又は周期が所定範囲を超えた回数が所定時間内に所定
回数以上となったとき単独運転と判断しインバータブリ
ッジ２を停止させれば確実に単独運転に対する保護が行
える。Therefore, in general, a measure is taken to stop the inverter bridge 2 when the islanding detection continues for a predetermined time. In the case of the present invention, however, the frequency or cycle exceeding the upper or lower limit once returns to within the limit. Therefore, the total time when the frequency or cycle of the voltage Va exceeds the predetermined range is equal to or more than the predetermined time within the predetermined time, or the number of times when the frequency or cycle exceeds the predetermined range is equal to or more than the predetermined number within the predetermined time. When it is determined that the operation is the islanding operation, and the inverter bridge 2 is stopped, the protection against the islanding operation can be surely performed.
【００４４】上記の単独運転判定手段は例えば異常検出
回路１９に１９ａで示すようにその機能を持たせること
ができ、例えばロジック回路やマイコンを設けることで
容易に実施できる。The above-mentioned islanding operation determining means can be provided with the function of the abnormality detecting circuit 19 as indicated by 19a, and can be easily implemented by providing a logic circuit or a microcomputer, for example.
【００４５】実施の形態５．また、上記実施の形態の上
記分散型電源出力電流制御手段の制御での電流指令の周
波数又は周期を変更するタイミングであるが、無秩序に
行うと出力電流Ｉａに直流成分が発生し変圧器６や負荷
９に対して好ましくないので、電流指令Ｉａ*又は出力
電流Ｉａのゼロクロス時点にて変更し、その１周期分は
電流指令Ｉａ*の周波数又は周期および振幅は変更しな
いようにする。これにより出力電流Ｉａが電流指令Ｉａ
*に合致するように制御されれば、出力電流Ｉａに直流
成分は発生しない。Embodiment 5 FIG. In addition, the timing of changing the frequency or cycle of the current command under the control of the distributed power supply output current control means of the above embodiment is random, but if performed randomly, a DC component is generated in the output current Ia and the transformer 6 or Since it is not preferable for the load 9, the current command Ia * or the output current Ia is changed at the time of zero crossing, and the frequency, cycle and amplitude of the current command Ia * are not changed for one cycle. As a result, the output current Ia becomes the current command Ia.
If the control is made to match *, no DC component is generated in the output current Ia.
【００４６】尚、上記各実施の形態では太陽光発電シス
テムのような直流電圧をインバータブリッジにて交流に
変換し、交流電力系統に連系する例について示したが、
マイクロタービン発電や風力発電では交流電圧を発電す
る場合もあるので、サイクロコンバータを用いて交流電
圧を直接交流電圧に変換し交流電力系統に連系する場合
の系統連系保護方法としても同様に適用でき同様の効果
を奏する。In each of the above embodiments, an example has been described in which a DC voltage as in a photovoltaic power generation system is converted into AC by an inverter bridge and connected to an AC power system.
In the case of microturbine power generation or wind power generation, AC voltage may be generated.Therefore, the same method can be applied as a grid connection protection method when AC voltage is directly converted to AC voltage using a cycloconverter and connected to AC power system. The same effect can be achieved.
【００４７】[0047]
【発明の効果】以上のようにこの発明によれば、発電電
力を交流電力に変換し交流電力系統と連系して運転する
分散型電源において、前記交流電力系統及び前記分散型
電源の出力の電圧位相に同期し所定の位相で出力する電
流指令に合致するように前記分散型電源の出力電流の制
御を行い、前記電圧の周波数の変化量を所定関数演算し
た分を現在又はそれ以前の電流指令又は電圧の周波数に
加えたものを新たな電流指令の周波数とすることを特徴
とする分散型電源の系統連系保護方法およびその装置と
したので、単独運転検出のために位相跳躍や出力電流の
直流分が増加することもなく、また変圧器の特性や同一
変圧器に接続されている分散型電源の台数に関係なく短
時間に確実に単独運転検出することができる。As described above, according to the present invention, in a distributed power supply that converts generated power into AC power and operates in connection with an AC power system, an output of the AC power system and the output of the distributed power supply is provided. The output current of the distributed power supply is controlled so as to match a current command output at a predetermined phase in synchronization with the voltage phase, and the amount of change in the frequency of the voltage calculated by a predetermined function is the current or previous current. A method for protecting a system interconnection of a distributed power supply and its device, characterized in that a frequency of a command or a voltage is added to a frequency of a new current command, so that a phase jump or an output current is detected for islanding detection. The DC operation of the power supply does not increase, and independent operation can be reliably detected in a short time regardless of the characteristics of the transformer or the number of distributed power supplies connected to the same transformer.
【００４８】また、発電電力を交流電力に変換し交流電
力系統と連系して運転する分散型電源において、前記交
流電力系統及び前記分散型電源の出力の電圧位相に同期
し所定の位相で出力する電流指令に合致するように前記
分散型電源の出力電流の制御を行い、前記電圧の周期の
変化量を所定関数演算した分を現在又はそれ以前の電流
指令又は電圧の周期に加えたものを新たな電流指令の周
期とすることを特徴とする分散型電源の系統連系保護方
法およびその装置としたので、同様に単独運転検出のた
めに位相跳躍や出力電流の直流分が増加することもな
く、また変圧器の特性や同一変圧器に接続されている分
散型電源の台数に関係なく短時間に確実に単独運転検出
することができる。Also, in a distributed power supply that operates by linking the generated power to AC power and being connected to an AC power system, an output is output at a predetermined phase in synchronization with the voltage phase of the output of the AC power system and the distributed power supply. The output current of the distributed power supply is controlled so as to match the current command to be performed, and the amount obtained by performing a predetermined function operation on the amount of change in the voltage cycle is added to the current or previous current command or voltage cycle. Since the method and the device for protecting the interconnection of the distributed power supply are characterized by using a new current command cycle, the phase jump and the DC component of the output current may also increase due to the detection of isolated operation. In addition, independent operation can be reliably detected in a short time regardless of the characteristics of the transformer and the number of distributed power supplies connected to the same transformer.
【００４９】また、電圧の所定位相間に発生した既知の
周期を有する基準クロックのクロック数をディジタル計
数して電圧の周期を計測するようにしたので、周期が正
確に検出でき、ひいては確実に単独運転検出することが
できる。Further, since the number of clocks of the reference clock having a known period generated during a predetermined phase of the voltage is digitally counted and the period of the voltage is measured, the period can be accurately detected, and therefore, the voltage can be accurately detected. Driving can be detected.
【００５０】また、電圧の周波数又は周期が所定範囲を
超えた延べ時間が所定時間内に所定時間以上、または周
波数又は周期が所定範囲を超えた回数が所定時間内に所
定回数以上発生したとき、単独運転と判断するようにし
たので、正確に単独運転を判断できる。When the total time when the frequency or cycle of the voltage exceeds the predetermined range exceeds a predetermined time within the predetermined time, or when the number of times that the frequency or cycle exceeds the predetermined range occurs more than the predetermined number within the predetermined time, Since the single operation is determined, the single operation can be accurately determined.
【００５１】また、電流指令の周波数又は周期の変更は
電流指令又は出力電流のゼロクロスにて行うようにした
ので、これにより変更したその１周期分は電流指令の周
波数又は周期および振幅は変更しないようにすれば、出
力電流が電流指令に合致するように制御され、これによ
り出力電流に直流成分が発生することはない。Since the frequency or cycle of the current command is changed at the zero cross of the current command or output current, the frequency, cycle and amplitude of the current command are not changed for one cycle. In this case, the output current is controlled so as to match the current command, so that a DC component does not occur in the output current.
【図１】 この発明の一実施の形態による分散型電源の
系統連系保護方法およびその装置を示す制御ブロック図
である。FIG. 1 is a control block diagram showing a system interconnection protection method and apparatus for a distributed power supply according to an embodiment of the present invention.
【図２】 負荷の位相特性曲線を示す図である。FIG. 2 is a diagram showing a phase characteristic curve of a load.
【図３】 この発明の他の実施の形態による分散型電源
の系統連系保護方法およびその装置を示す制御ブロック
図である。FIG. 3 is a control block diagram showing a system interconnection protection method and apparatus for a distributed power supply according to another embodiment of the present invention.
【図４】 この発明の他の実施の形態の周期検出方法を
示すタイムチャートである。FIG. 4 is a time chart showing a cycle detection method according to another embodiment of the present invention.
【図５】 従来の系統連系保護方法を示す制御ブロック
図である。FIG. 5 is a control block diagram showing a conventional system interconnection protection method.
【図６】 従来の系統連系保護方法の位相・ゲイン設定
特性図である。FIG. 6 is a phase / gain setting characteristic diagram of a conventional system interconnection protection method.
【図７】 交圧器電流電圧波形である。FIG. 7 is a cross-sectional current / voltage waveform.
１ 直流電源、２ インバータブリッジ、３ リアクト
ル、４ コンデンサ、５ 電流検出器、６ 変圧器、７
しゃ断器、８ 交流電力系統、９ 負荷、１０ 電圧
検出器、１１，１３ 増幅器、１２ 電流基準回路、１
４ ＰＷＭ制御部、１５ 駆動部、１７ 電圧リレー、
１８ 周波数リレー、１９ 異常検出回路、２２ 周波
数検出回路、２３，４３ 変化量検出回路、２３ａ，４
３ａ 関数演算器、２３ｂ，４３ｂ 加算器、４２ 周
期検出回路、４８ 周期リレー。1 DC power supply, 2 inverter bridge, 3 reactor, 4 capacitor, 5 current detector, 6 transformer, 7
Circuit breaker, 8 AC power system, 9 load, 10 voltage detector, 11, 13 amplifier, 12 current reference circuit, 1
4 PWM control unit, 15 drive unit, 17 voltage relay,
18 frequency relay, 19 abnormality detection circuit, 22 frequency detection circuit, 23, 43 change amount detection circuit, 23a, 4
3a Function calculator, 23b, 43b Adder, 42 cycle detection circuit, 48 cycle relay.
Claims (10)
統と連系して運転する分散型電源において、 前記交流電力系統及び前記分散型電源の出力の電圧位相
に同期し所定の位相で出力する電流指令に合致するよう
に前記分散型電源の出力電流の制御を行い、前記電圧の
周波数の変化量を所定関数演算した分を現在又はそれ以
前の電流指令又は電圧の周波数に加えたものを新たな電
流指令の周波数とすることを特徴とする分散型電源の系
統連系保護方法。1. A distributed power supply that converts generated power into AC power and operates in connection with an AC power system, wherein the power is output at a predetermined phase in synchronization with the voltage phases of the outputs of the AC power system and the distributed power supply. The output current of the distributed power supply is controlled so as to match the current command to be performed, and the amount obtained by performing a predetermined function operation on the amount of change in the frequency of the voltage is added to the current or previous current command or voltage frequency. A system connection protection method for a distributed power supply, characterized in that a new current command frequency is used.
統と連系して運転する分散型電源において、 前記交流電力系統及び前記分散型電源の出力の電圧位相
に同期し所定の位相で出力する電流指令に合致するよう
に前記分散型電源の出力電流の制御を行い、前記電圧の
周期の変化量を所定関数演算した分を現在又はそれ以前
の電流指令又は電圧の周期に加えたものを新たな電流指
令の周期とすることを特徴とする分散型電源の系統連系
保護方法。2. A distributed power supply that converts generated power into AC power and operates in connection with an AC power system, wherein the power is output at a predetermined phase in synchronization with the voltage phases of the outputs of the AC power system and the distributed power supply. The output current of the distributed power supply is controlled so as to match the current command to be performed, and the amount obtained by performing a predetermined function operation on the amount of change in the voltage cycle is added to the current or previous current command or voltage cycle. A system connection protection method for a distributed power supply, characterized by using a new current command period.
を有する基準クロックのクロック数をディジタル計数し
て電圧の周期を計測することを特徴とする請求項２に記
載の分散型電源の系統連系保護方法。3. The distributed power supply system according to claim 2, wherein the number of clocks of a reference clock having a known period generated during a predetermined phase of the voltage is digitally counted to measure the period of the voltage. Interconnection protection method.
た延べ時間が所定時間内に所定時間以上、または周波数
又は周期が所定範囲を超えた回数が所定時間内に所定回
数以上発生したとき、単独運転と判断することを特徴と
する請求項１ないし３のいずれかに記載の分散型電源の
系統連系保護方法。4. When the total time when the frequency or cycle of the voltage exceeds the predetermined range exceeds a predetermined time within the predetermined time, or when the number of times that the frequency or cycle exceeds the predetermined range occurs more than the predetermined number within the predetermined time, The method according to any one of claims 1 to 3, wherein the operation is determined to be an isolated operation.
指令又は出力電流のゼロクロスにて行うことを特徴とす
る請求項１ないし４のいずれかに記載の分散型電源の系
統連系保護方法。5. The method according to claim 1, wherein the frequency or cycle of the current command is changed at a zero crossing of the current command or the output current.
統と連系して運転する分散型電源において、 負荷に供給される交流電圧の周波数を検出する周波数検
出手段と、 前記電圧の周波数の変化量を所定関数演算した分を、現
在又はそれ以前の電流指令又は電圧の周波数に加えたも
のを新たな電流指令の周波数として求める電流指令周波
数演算手段と、 前記交流電力系統及び前記分散型電源の出力の電圧位相
に同期し所定の位相で出力する前記周波数の電流指令に
合致するように前記分散型電源の出力電流の制御を行う
分散型電源出力電流制御手段と、 を備えたことを特徴とする分散型電源の系統連系保護装
置。6. A distributed power supply that converts generated power into AC power and operates in connection with an AC power system, comprising: frequency detection means for detecting a frequency of an AC voltage supplied to a load; Current command frequency calculating means for obtaining a value obtained by adding the amount of change calculated by the predetermined function to the current or previous current command or voltage frequency as a new current command frequency; and the AC power system and the distributed power supply Distributed power supply output current control means for controlling the output current of the distributed power supply so as to match the current command of the frequency which is output in a predetermined phase in synchronization with the voltage phase of the output of the power supply. A system interconnection protection device for distributed power supplies.
統と連系して運転する分散型電源において、 負荷に供給される交流電圧の周期を検出する周期検出手
段と、 前記電圧の周期の変化量を所定関数演算した分を、現在
又はそれ以前の電流指令又は電圧の周期に加えたものを
新たな電流指令の周期として求める電流指令周期演算手
段と、 前記交流電力系統及び前記分散型電源の出力の電圧位相
に同期し所定の位相で出力する前記周期の電流指令に合
致するように前記分散型電源の出力電流の制御を行う分
散型電源出力電流制御手段と、 を備えたことを特徴とする分散型電源の系統連系保護装
置。7. A distributed power supply that converts generated power into AC power and operates in connection with an AC power system, wherein: a cycle detection means for detecting a cycle of an AC voltage supplied to a load; Current command cycle calculating means for calculating a value obtained by adding the amount of change calculated by the predetermined function to the current or previous cycle of the current command or voltage as a new current command cycle; and the AC power system and the distributed power supply. Distributed power supply output current control means for controlling the output current of the distributed power supply so as to match the current command of the cycle synchronized with the output voltage phase and output at a predetermined phase. A system interconnection protection device for distributed power supplies.
に発生した既知の周期を有する基準クロック数をデジタ
ル計数して電圧の周期を計測することを特徴とする請求
項７に記載の分散型電源の系統連系保護装置。8. The dispersion according to claim 7, wherein said period detecting means digitally counts the number of reference clocks having a known period generated during a predetermined phase of the voltage and measures the period of the voltage. Type power system grid protection device.
た延べ時間が所定時間内に所定時間以上、または周波数
又は周期が所定範囲を超えた回数が所定時間内に所定回
数以上発生したとき、単独運転と判断する単独運転判定
手段をさらに備えたことを特徴とする請求項６ないし８
のいずれかに記載の分散型電源の系統連系保護装置。9. When the total time when the frequency or cycle of the voltage exceeds a predetermined range exceeds a predetermined time within a predetermined time, or when the number of times that the frequency or cycle exceeds the predetermined range occurs more than a predetermined number within the predetermined time, 9. The vehicle according to claim 6, further comprising an islanding operation judging means for judging the islanding operation.
A system interconnection protection device for a distributed power supply according to any one of the above.
いて、電流指令の周波数又は周期の変更は電流指令又は
出力電流のゼロクロスにて行うことを特徴とする請求項
６ないし９のいずれかに記載の分散型電源の系統連系保
護装置。10. The distributed power supply output current control means according to claim 6, wherein the frequency or cycle of the current command is changed at a zero cross of the current command or output current. Grid connection protection device for distributed power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000076236A JP4038318B2 (en) | 2000-03-17 | 2000-03-17 | System interconnection protection method and apparatus for distributed power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000076236A JP4038318B2 (en) | 2000-03-17 | 2000-03-17 | System interconnection protection method and apparatus for distributed power supply |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001268802A true JP2001268802A (en) | 2001-09-28 |
| JP4038318B2 JP4038318B2 (en) | 2008-01-23 |
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ID=18594008
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|---|---|---|---|
| JP2000076236A Expired - Fee Related JP4038318B2 (en) | 2000-03-17 | 2000-03-17 | System interconnection protection method and apparatus for distributed power supply |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007318928A (en) * | 2006-05-26 | 2007-12-06 | Sanken Electric Co Ltd | Inverter device |
| JP2008079439A (en) * | 2006-09-21 | 2008-04-03 | Fuji Electric Holdings Co Ltd | Control system of step-up chopper |
| JP2008271709A (en) * | 2007-04-20 | 2008-11-06 | Toshiba Consumer Electronics Holdings Corp | Power conversion apparatus |
| JP2012044815A (en) * | 2010-08-20 | 2012-03-01 | Toshiba Corp | Individual operation detector and individual operation detection method |
| JP2013078207A (en) * | 2011-09-30 | 2013-04-25 | Sanyo Electric Co Ltd | Electric power conversion system |
| JP2016092851A (en) * | 2014-10-29 | 2016-05-23 | 三菱電機株式会社 | Controller for individual operation detection, individual operation detector and individual operation detection method |
| KR101778772B1 (en) * | 2014-09-30 | 2017-09-19 | 한국전기연구원 | The System and Method of Detecting Events by Checking Frequency in Microgrid |
-
2000
- 2000-03-17 JP JP2000076236A patent/JP4038318B2/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007318928A (en) * | 2006-05-26 | 2007-12-06 | Sanken Electric Co Ltd | Inverter device |
| JP4662064B2 (en) * | 2006-05-26 | 2011-03-30 | サンケン電気株式会社 | Inverter device |
| JP2008079439A (en) * | 2006-09-21 | 2008-04-03 | Fuji Electric Holdings Co Ltd | Control system of step-up chopper |
| JP2008271709A (en) * | 2007-04-20 | 2008-11-06 | Toshiba Consumer Electronics Holdings Corp | Power conversion apparatus |
| JP2012044815A (en) * | 2010-08-20 | 2012-03-01 | Toshiba Corp | Individual operation detector and individual operation detection method |
| JP2013078207A (en) * | 2011-09-30 | 2013-04-25 | Sanyo Electric Co Ltd | Electric power conversion system |
| KR101778772B1 (en) * | 2014-09-30 | 2017-09-19 | 한국전기연구원 | The System and Method of Detecting Events by Checking Frequency in Microgrid |
| JP2016092851A (en) * | 2014-10-29 | 2016-05-23 | 三菱電機株式会社 | Controller for individual operation detection, individual operation detector and individual operation detection method |
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| Publication number | Publication date |
|---|---|
| JP4038318B2 (en) | 2008-01-23 |
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