JP2003047156A - Linkage protection system for distributed power supply facility - Google Patents
Linkage protection system for distributed power supply facilityInfo
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- JP2003047156A JP2003047156A JP2001227211A JP2001227211A JP2003047156A JP 2003047156 A JP2003047156 A JP 2003047156A JP 2001227211 A JP2001227211 A JP 2001227211A JP 2001227211 A JP2001227211 A JP 2001227211A JP 2003047156 A JP2003047156 A JP 2003047156A
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- voltage
- distributed power
- power supply
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Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、分散型電源設備の
連系保護システムに係り、特に、瞬時電圧低下と単独運
転を検出して分散型電源設備や負荷を保護するに好適な
分散型電源設備の連系保護システムに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interconnection protection system for distributed power supply equipment, and more particularly to a distributed power supply suitable for protecting the distributed power supply equipment and load by detecting instantaneous voltage drop and islanding operation. It relates to the interconnection protection system for equipment.
【0002】[0002]
【従来の技術】工場や大規模ビルなどの需要家の電力設
備においては、電力系統側の給電停止時のバックアップ
対策や不足電力を補うために、あるいはコージェネレー
ションシステムのように電熱併給システムとして総合エ
ネルギー費用を削減する目的で、分散型電源を自家発電
用電源として設置し、電力系統と分散型電源とを連系し
て運用する構成が増加している。2. Description of the Related Art In electric power equipment for customers such as factories and large-scale buildings, backup measures when power supply is stopped on the electric power system side, supplementary power shortages, or integrated cogeneration systems such as cogeneration systems For the purpose of reducing energy costs, there is an increasing number of configurations in which a distributed power source is installed as a power source for private power generation and the power system and the distributed power source are interconnected and operated.
【0003】従来の分散型電源設備の連系保護システム
は、分散型電源を持たない受電設備と同様に、保護の目
的に応じて個別に設置された専用の保護装置を協調制御
して運用されている。例えば、落雷などによる電力系統
側の短時間故障により生じる瞬時電圧低下に対しては、
例えば、特開平10−336878号公報に記載されて
いるように、電力系統と分散型電源設備との間に配置さ
れて半導体スイッチにより構成された遮断装置により、
電力系統から需要家の分散型電源設備と重要負荷を高速
に解列(通常、20ms以内)することで、電圧低下に
よる被害を軽減させる瞬時電圧低下防止装置が提案され
ている。[0003] A conventional interconnection protection system for distributed power supply equipment is operated by cooperatively controlling dedicated protection devices individually installed according to the purpose of protection, as in power receiving equipment without a distributed power supply. ing. For example, for a momentary voltage drop caused by a short time failure on the power system side due to a lightning strike,
For example, as described in Japanese Patent Application Laid-Open No. 10-336878, a breaker arranged between a power system and a distributed power supply facility and configured by semiconductor switches,
There has been proposed an instantaneous voltage drop prevention device that reduces damage caused by a voltage drop by rapidly disconnecting (typically within 20 ms) the distributed power supply equipment and important loads of consumers from the power system.
【0004】また、系統給電停止時の保護上の対策(感
電などの防止)として、必要な分散型電源の単独運転防
止に対しては、電力会社の変電所と分散型電源を持つ需
要家との間で通信を行う転送遮断装置や、分散型電源側
で単独運転を検出する専用の検出装置が設置されてい
る。ここで、単独運転とは、電力系統側の電源が喪失し
たときに、分散型電源が電力系統から解列されないまま
になり、局所的に分散型電源から他の一般需要家に電力
を供給している状態を言う。Further, as a measure for protection when power supply to the system is stopped (prevention of electric shock, etc.), in order to prevent the isolated operation of the distributed power source, a substation of an electric power company and a customer having the distributed power source are required. A transfer cutoff device for communication between the two and a dedicated detection device for detecting isolated operation on the distributed power source side are installed. Here, isolated operation means that when the power source on the power system side is lost, the distributed power source remains undisconnected from the power system, and power is locally supplied from the distributed power source to other general consumers. Say the state.
【0005】単独運転状態になると、本来無電圧である
べき系統が分散型電源によって充電されるため、そのま
までは安全上に問題を生じることになる。さらに、分散
型電源から系統が充電された状態で系統が自動的に再閉
路されると、非同期投入によって機器などが損傷する問
題が生じる。このため、このような問題点が生ずるのを
防止するために、連系ガイドラインにより、需要家には
単独運転を検出するための装置を設けるとともに、単独
運転時に系統と分散型電源とを解列する解列手段を設置
することが義務付けられている。In the isolated operation state, a system which should have no voltage is charged by the distributed power source, which causes a safety problem as it is. Furthermore, if the system is automatically reclosed while the system is charged from the distributed power source, there is a problem that the equipment is damaged due to asynchronous closing. For this reason, in order to prevent such problems from occurring, the grid interconnection guidelines are provided for consumers to detect the islanding operation, and the grid and the distributed power source are disconnected during the islanding operation. It is obligatory to install a disconnecting means to operate.
【0006】分散型電源設備の連系保護システムにおい
て、瞬時電圧低下などの異常を検出するに際しては、例
えば、各相の電圧の平均値を算出して基準値と比較する
方法や、各相の電圧および電流の瞬時値(絶対値、時間
変化率など)を基準値と比較する方法の他、特開平6−
82499号公報に記載されているように、三相の電圧
の自乗和を用いる方法や、特開平5−297030号公
報に記載されているように、三相/二相変換による合成
電圧ベクトルを用いる方法が提案されているとともに、
単独運転を検出する方法として、特開平10−2341
36号公報に記載されているように、系統側の電圧と分
散電源側の電圧とを検出し、各検出電圧の波形から両者
の位相差と周波数差および電力方向を求め、これらの値
が一定値を超えたときの組合わせから単独運転を検出す
る方法が提案されている。In detecting an abnormality such as a momentary voltage drop in the interconnection protection system for distributed power equipment, for example, a method of calculating the average value of the voltage of each phase and comparing it with a reference value, or In addition to the method of comparing the instantaneous value of voltage and current (absolute value, rate of change with time, etc.) with a reference value, JP-A-6-
As disclosed in Japanese Patent No. 82499, a method of using the sum of squares of three-phase voltages, and as described in Japanese Patent Laid-Open No. 5-297030, a combined voltage vector by three-phase / two-phase conversion is used. While the method is proposed,
As a method for detecting the islanding operation, Japanese Patent Laid-Open No. 10-2341
As described in Japanese Patent Laid-Open No. 36-36, the voltage on the system side and the voltage on the distributed power source side are detected, the phase difference, frequency difference, and power direction of the two are found from the waveforms of the detected voltages, and these values are constant. A method has been proposed in which islanding is detected from the combination when the value is exceeded.
【0007】[0007]
【発明が解決しようとする課題】従来の連系保護システ
ムにおいては、保護の目的ごとに専用の装置を個別に設
置しているため、需要家の設備投資が増加するととも
に、各装置を協調して運用するための保護システムの構
成が複雑化し、システム全体の制御の応答性/信頼性が
低下するという問題点がある。そこで、単一の制御装置
に複数の保護機能を持たせて集中制御することも考えら
れるが、単一の制御装置に単に複数の保護機能を持たせ
ても、1つの演算処理装置で処理する演算量が増加する
だけで演算処理を円滑に行うことができない。In the conventional interconnection protection system, since dedicated devices are individually installed for the purpose of protection, the capital investment of customers increases and the devices cooperate with each other. However, there is a problem that the configuration of the protection system for operating the system as a whole becomes complicated, and the responsiveness / reliability of control of the entire system deteriorates. Therefore, it is conceivable to provide a single control device with a plurality of protection functions for centralized control. However, even if a single control device is simply provided with a plurality of protection functions, it is processed by one arithmetic processing unit. The calculation processing cannot be smoothly performed only by the increase in the calculation amount.
【0008】また、従来の連系保護システムにおいて異
常を検出するに際して、瞬時電圧低下の検出を行うに
も、電圧の平均値を用いる方法では、積分処理を行うた
めに、原理的に検出に時間がかかるという問題点があ
る。また各相ごとの電圧・電流の瞬時値を用いる方法で
は、検出時間は短いが、系統のわずかな擾乱(波形歪
み、周波数変動など)に対しても動作する可能性があ
る。また各相の電圧の自乗和や三層/二相変換による合
成ベクトルを用いる方法では、各相の電圧低下の割合に
ばらつきがあるような場合には、電圧低下の小さい、あ
るいは遅い相に影響されて検出時間が長くなり、検出不
能になる恐れがある。Further, when detecting an abnormality in the conventional interconnection protection system, the method of using the average value of the voltage also detects the instantaneous voltage drop, but since the integration process is performed, the detection time is theoretically long. There is a problem that it costs. Further, in the method using the instantaneous value of the voltage / current for each phase, the detection time is short, but there is a possibility of operating even for a slight system disturbance (waveform distortion, frequency fluctuation, etc.). Further, in the method of using the sum of squares of the voltages of the respective phases or the combined vector by the three-layer / two-phase conversion, when there is a variation in the rate of the voltage decrease of each phase, the phase with a small voltage decrease or the slow phase is affected. As a result, the detection time becomes long and there is a possibility that the detection becomes impossible.
【0009】本発明の課題は、演算処理を円滑に行うこ
とができる分散型電源設備の連系保護システムを提供す
ることにある。An object of the present invention is to provide an interconnection protection system for distributed power supply equipment which can smoothly perform arithmetic processing.
【0010】本発明の他の課題は、瞬時電圧検出を高速
に且つ高精度に行うことができる分散型電源設備の連系
保護システムを提供することにある。Another object of the present invention is to provide an interconnection protection system for distributed power supply equipment capable of detecting instantaneous voltage at high speed and with high accuracy.
【0011】[0011]
【課題を解決するための手段】前記課題を解決するため
に、本発明は、三相の電力系統と分散型電源とを結ぶ母
線に設置されて前記母線を指令に応じて開閉する母線連
絡用遮断器と、前記遮断器より電力系統側の母線電圧を
検出する系統側電圧検出器と、前記遮断器より分散型電
源側の母線電圧を検出する分散型電源側電圧検出器と、
前記母線の通過電流を検出する電流検出器と、前記系統
側電圧検出器と前記分散型電源側電圧検出器および前記
電流検出器の検出出力を基に前記電力系統の異常の有無
を判定し、この判定結果に従った前記遮断器の遮断・投
入を制御する制御手段とを備え、前記制御手段は、前記
系統側電圧検出器の検出電圧と前記電流検出器の検出電
流を演算処理して瞬時電圧低下を検出する瞬時電圧低下
検出手段と、前記分散型電源側電圧検出器の検出電圧の
周波数変化率から単独運転を検出する単独運転検出手段
と、前記瞬時電圧低下検出手段の検出出力または前記単
独運転検出手段の検出出力に応答して前記遮断器に対し
て遮断指令を出力する遮断指令出力手段とを含んで構成
されてなる分散型電源設備の連系保護システムを構成し
たものである。In order to solve the above-mentioned problems, the present invention is for connecting to a bus bar that connects a three-phase power system and a distributed power source and opens and closes the bus bar according to a command. A circuit breaker, a system voltage detector that detects a bus voltage on the power system side from the circuit breaker, and a distributed power supply voltage detector that detects a bus voltage on the distributed power supply side from the circuit breaker,
A current detector for detecting a passing current of the bus bar, the presence or absence of abnormality of the power system based on the detection output of the system side voltage detector and the distributed power supply side voltage detector and the current detector, And a control means for controlling the interruption / closing of the circuit breaker according to the determination result, wherein the control means instantaneously performs arithmetic processing on the detection voltage of the system side voltage detector and the detection current of the current detector. Instantaneous voltage drop detection means for detecting voltage drop, islanding operation detection means for detecting islanding operation from the frequency change rate of the detected voltage of the distributed power supply side voltage detector, detection output of the instantaneous voltage drop detection means or the A disconnection command output unit that outputs a disconnection command to the circuit breaker in response to a detection output of the islanding operation detection unit, constitutes a system for protecting interconnection of distributed power equipment.
【0012】前記分散型電源設備の連系保護システムを
構成するに際しては、以下の要素を付加することができ
る。When constructing the interconnection protection system for the distributed power equipment, the following elements can be added.
【0013】(1)前記制御手段は、前記系統側電圧検
出器の検出電圧と前記分散電源側電圧検出器の検出電圧
との位相差を検出する位相差検出手段と、前記位相差検
出手段の検出出力により同期タイミングを判定する同期
判定手段と、前記同期判定手段から同期タイミングであ
るとの判定結果が出力されたときに前記遮断器に対して
投入指令を出力する投入指令出力手段とを含んで構成さ
れてなる。(1) The control means includes a phase difference detection means for detecting a phase difference between a detection voltage of the system side voltage detector and a detection voltage of the distributed power supply side voltage detector, and the phase difference detection means. Includes a synchronization determination unit that determines the synchronization timing based on the detection output, and a closing command output unit that outputs a closing command to the circuit breaker when the determination result that the synchronization timing is the synchronization timing is output from the synchronization determination unit. It consists of.
【0014】(2)前記制御手段は、前記分散型電源の
運転状態を制御する分散型電源制御手段を含んで構成さ
れてなる。(2) The control means includes a distributed power supply control means for controlling the operating state of the distributed power supply.
【0015】(3)前記瞬時電圧低下検出手段は、前記
系統側電圧検出器の検出出力を三相/二相変換して合成
電圧ベクトルの絶対値を算出する絶対値算出手段と、前
記絶対値算出手段の算出による絶対値と異常判定のしき
い値とを比較して瞬時電圧低下の発生の有無を判定する
瞬時電圧低下判定手段と、前記電流検出器の検出による
各相の電流を演算処理して異常を検出する電流異常検出
手段と、前記電流異常検出手段の検出出力により前記異
常判定のしきい値を補正する補正手段とから構成されて
なる。(3) The instantaneous voltage drop detecting means includes an absolute value calculating means for converting the detection output of the system side voltage detector into a three-phase / two-phase conversion to calculate an absolute value of a combined voltage vector, and the absolute value. Instantaneous voltage drop determination means for comparing the absolute value calculated by the calculation means with a threshold value for abnormality determination to determine whether or not an instantaneous voltage drop has occurred, and a current for each phase detected by the current detector is processed. And an abnormality detecting unit for detecting an abnormality, and a correcting unit for correcting the abnormality determination threshold value by the detection output of the current abnormality detecting unit.
【0016】(4)前記瞬時電圧低下検出手段は、前記
系統側電圧検出器の検出出力を三相/二相変換して合成
電圧ベクトルの絶対値を算出する絶対値算出手段と、前
記絶対値算出手段の算出による絶対値と異常判定のしき
い値とを比較して瞬時電圧低下の発生の有無を判定する
瞬時電圧低下判定手段と、前記系統側電圧検出器の検出
による各相の電圧を演算処理して異常を検出する電圧異
常検出手段と、前記電圧異常検出手段の検出出力により
前記異常判定のしきい値を補正する補正手段とから構成
されてなる。(4) The instantaneous voltage drop detecting means is an absolute value calculating means for converting the detection output of the system side voltage detector into a three-phase / two-phase conversion to calculate an absolute value of a combined voltage vector, and the absolute value. The instantaneous voltage drop determination means for comparing the absolute value calculated by the calculation means with the threshold value for abnormality determination to determine whether or not an instantaneous voltage drop has occurred, and the voltage of each phase detected by the system side voltage detector It is composed of a voltage abnormality detecting means for performing arithmetic processing to detect an abnormality, and a correcting means for correcting the threshold value of the abnormality determination by the detection output of the voltage abnormality detecting means.
【0017】(5)前記瞬時電圧低下検出手段は、前記
系統側電圧検出器の検出出力を三相/二相変換して合成
電圧ベクトルの絶対値を算出する絶対値算出手段と、前
記絶対値算出手段の算出による絶対値と異常判定のしき
い値とを比較して瞬時電圧低下の発生の有無を判定する
瞬時電圧低下判定手段と、前記系統側電圧検出器の検出
による各相の電圧を演算処理して異常を検出する電圧異
常検出手段と、前記電流検出器の検出による各相の電流
を演算処理して異常を検出する電流異常検出手段と、前
記電流異常検出手段の検出出力または前記電圧異常検出
手段の検出出力により前記異常判定のしきい値を補正す
る補正手段とから構成されてなる。(5) The instantaneous voltage drop detecting means includes an absolute value calculating means for converting the detection output of the system side voltage detector into a three-phase / two-phase signal to calculate an absolute value of a combined voltage vector, and the absolute value. The instantaneous voltage drop determination means for comparing the absolute value calculated by the calculation means with the threshold value for abnormality determination to determine whether or not an instantaneous voltage drop has occurred, and the voltage of each phase detected by the system side voltage detector Voltage abnormality detection means for performing arithmetic processing to detect abnormality, current abnormality detection means for performing arithmetic processing on the current of each phase detected by the current detector to detect abnormality, detection output of the current abnormality detection means or the above It comprises a correction means for correcting the threshold value for the abnormality determination based on the detection output of the voltage abnormality detection means.
【0018】(6)前記電流異常検出手段は、前記電流
検出器の検出による各相の電流の時間変化率のうちいず
れかの時間変化率が変化率判定値を超えたときに異常を
検出してなる。(6) The current abnormality detecting means detects an abnormality when one of the time change rates of the currents of the respective phases detected by the current detector exceeds a change rate determination value. It becomes.
【0019】(7)前記電流異常検出手段は、前記電流
検出器の検出による各相の電流の絶対値のうちいずれか
の絶対値が絶対値判定値を超えたときに異常を検出して
なる。(7) The current abnormality detecting means detects an abnormality when one of the absolute values of the current of each phase detected by the current detector exceeds an absolute value judgment value. .
【0020】(8)前記電圧異常検出手段は、前記系統
側電圧検出器の検出による各相の電圧降下量のうちいず
れかの電圧降下量が電圧判定値以下になったときに異常
を検出してなる。(8) The voltage abnormality detecting means detects an abnormality when one of the voltage drop amounts of the respective phases detected by the system side voltage detector becomes equal to or less than the voltage judgment value. It becomes.
【0021】前記した手段によれば、単一の制御手段に
より、瞬時電圧低下および単独運転を検出し、この検出
結果にしたがって母線連絡用遮断器を遮断する制御を行
い、瞬時電圧低下のための演算処理と単独運転検出のた
めの演算処理の共有化を図るようにしたため、演算量を
低減することができ、演算処理を円滑に行うことができ
る。According to the above-mentioned means, the single control means detects the instantaneous voltage drop and the islanding operation, and controls the disconnection of the busbar circuit breaker in accordance with the detection result, so as to reduce the instantaneous voltage. Since the calculation process and the calculation process for islanding operation detection are shared, the calculation amount can be reduced and the calculation process can be smoothly performed.
【0022】また、瞬時電圧低下を検出するに際して、
系統側電圧検出器の検出出力を三相/二相変換して合成
電圧ベクトルの絶対値を算出し、この絶対値と異常判定
のしきい値とを比較して瞬時電圧低下の発生の有無を判
定するときに、電圧異常検出手段または電流異常検出手
段の検出出力により異常判定のしきい値を補正し、例え
ば、異常判定のしきい値を大きくして検出感度を上げる
ようにしているため、ノイズ処理、故障継続性判定など
の複雑な処理を加えることなく、外乱に強く且つ所定の
時間内で瞬時電圧低下を高精度に検出することができ
る。When detecting the instantaneous voltage drop,
Three-phase / two-phase conversion of the detection output of the system side voltage detector is performed to calculate the absolute value of the combined voltage vector, and this absolute value is compared with the threshold value for abnormality determination to determine whether or not an instantaneous voltage drop has occurred. At the time of determination, the threshold value of the abnormality determination is corrected by the detection output of the voltage abnormality detection means or the current abnormality detection means, and for example, the detection threshold is increased by increasing the threshold value of the abnormality determination, It is possible to detect an instantaneous voltage drop with high accuracy against a disturbance and within a predetermined time without adding complicated processing such as noise processing and failure continuity determination.
【0023】[0023]
【発明の実施の形態】以下、本発明の一実施形態を図面
に基づいて説明する。図1は本発明の一実施形態を示す
分散型電源設備の連系保護システムの単線結線図であ
る。図1に示す需要家の主回路は、電力系統4に接続さ
れた負荷2を含む系と、分散型電源となる発電装置51
とこれに接続された負荷3を含む系を母線16で連系す
る方式であって、分散型電源を保有する需要家が電力系
統4と連系する場合に一般的に用いられる回路構成であ
る。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a single-line connection diagram of an interconnection protection system for distributed power supply equipment showing an embodiment of the present invention. The main circuit of the consumer shown in FIG. 1 includes a system including a load 2 connected to a power system 4 and a power generation device 51 serving as a distributed power source.
This is a system in which a system including a load 3 and a load 3 connected thereto is interconnected by a bus bar 16, and is a circuit configuration generally used when a customer who has a distributed power source is interconnected with a power system 4. .
【0024】図1において、三相の電力系統4から電力
を受ける受電点には遮断器6が設置されており、この遮
断器6は受電用変圧器10、遮断器8を介して負荷2に
接続されている。受電用変圧器10と遮断器8との接続
点には母線16が接続されている。In FIG. 1, a circuit breaker 6 is installed at a power receiving point for receiving electric power from a three-phase power system 4, and the circuit breaker 6 is connected to a load 2 via a power receiving transformer 10 and a circuit breaker 8. It is connected. A bus bar 16 is connected to a connection point between the power receiving transformer 10 and the circuit breaker 8.
【0025】一方、自家発電設備となる分散型電源設備
5は分散型電源としての発電装置51、制御装置52を
備えて構成されており、発電装置51は遮断器7、9を
介して負荷3に接続されている。そして遮断器7と遮断
器9との接続点に母線16が接続されている。制御装置
52は連系保護システム1の制御装置11から電圧変動
指令を受け、この指令にしたがって発電装置51の出力
電圧を制御するように構成されている。負荷3は負荷2
よりも高い電力品質が要求されており、通常短時間の停
電も許容されないもので構成されている。On the other hand, the distributed power supply facility 5 serving as a private power generation facility is configured to include a power generation device 51 as a distributed power source and a control device 52, and the power generation device 51 connects the load 3 via the circuit breakers 7 and 9. It is connected to the. A bus bar 16 is connected to a connection point between the circuit breakers 7 and 9. The control device 52 is configured to receive a voltage fluctuation command from the control device 11 of the interconnection protection system 1 and control the output voltage of the power generation device 51 according to this command. Load 3 is load 2
Higher power quality is required, and it usually consists of those that cannot tolerate short power failures.
【0026】連系保護システム1は、系統側の系と分散
電源側の系とを結ぶ母線16の途中に挿入されて配置さ
れた母線連絡用遮断器12、母線の通過電流Iを検出す
る電流検出器13、遮断器12より電力系統側の母線電
圧Vsを検出する系統側電圧検出器14、遮断器12よ
り分散電源側の母線電圧Vgを検出する分散電源側電圧
検出器15、電流検出器13の検出電流、電圧検出器1
4、15の検出電圧を基に電力系統4の異常の有無を判
定し、この判定結果にしたがった遮断器12の遮断・投
入を制御する制御手段としての制御装置11を備えて構
成されている。The interconnection protection system 1 includes a busbar breaker 12 inserted and arranged in the middle of a busbar 16 connecting a system on the system side and a system on the distributed power supply side, and a current for detecting a passing current I of the busbar. A detector 13, a system side voltage detector 14 that detects a bus voltage Vs on the power system side from the circuit breaker 12, a distributed power source side voltage detector 15 that detects a bus line voltage Vg on the distributed power source side from the circuit breaker 12, and a current detector 13 detection current, voltage detector 1
It is configured to include a control device 11 as a control unit that determines whether or not there is an abnormality in the power system 4 based on the detected voltages of 4 and 15 and controls the interruption / closing of the circuit breaker 12 according to the determination result. .
【0027】本実施形態による連系保護システム1で
は、母線連絡用遮断器12として、高速動作可能な真空
遮断器あるいは半導体式の遮断器が採用されている。ま
た制御装置11は、電圧検出器14の検出電圧と電流検
出器13の検出電流を演算処理して瞬時電圧低下を検出
する瞬時電圧低下検出手段と、電圧検出器15の検出電
圧の周波数変化率から単独運転を検出する単独運転検出
手段と、各検出手段の検出出力に応答して遮断器12に
対して遮断指令を出力する遮断指令出力手段としての機
能を備えて構成されている。さらに、制御装置11は、
電圧検出器14の検出電圧と電圧検出器15の検出電圧
との位相差を検出する位相差検出手段と、位相差検出手
段の検出出力により同期タイミングを判定する同期判定
手段と、この同期判定手段から同期タイミングであると
の判定結果が出力されたときに遮断器12に対して投入
指令を出力する投入指令出力手段としての機能を備えて
構成されている。以下、制御装置11の具体的制御アル
ゴリズムを図2ないし図5を用いて詳細に説明する。In the interconnection protection system 1 according to the present embodiment, a vacuum circuit breaker or a semiconductor type circuit breaker that can operate at high speed is adopted as the bus bar circuit breaker 12. In addition, the control device 11 performs an arithmetic process on the detected voltage of the voltage detector 14 and the detected current of the current detector 13 to detect an instantaneous voltage drop, and a frequency change rate of the detected voltage of the voltage detector 15. It has a function as an isolated operation detecting means for detecting an isolated operation, and a function as an interruption command output means for outputting an interruption command to the circuit breaker 12 in response to the detection output of each detecting means. Further, the control device 11 is
Phase difference detecting means for detecting the phase difference between the detected voltage of the voltage detector 14 and the detected voltage of the voltage detector 15, a synchronization judging means for judging the synchronization timing by the detection output of the phase difference detecting means, and this synchronization judging means. Is provided with a function as closing command output means for outputting a closing command to the circuit breaker 12 when a determination result indicating that the synchronization timing is output. Hereinafter, a specific control algorithm of the control device 11 will be described in detail with reference to FIGS.
【0028】制御装置11は、図2に示すように、電流
検出器13、電圧検出器14、15の検出出力(アナロ
グ量の信号)をディジタル信号に変換するA/D変換部
110、電流情報演算部111、比較部112、電圧情
報演算部114、比較部115、前処理判定部117、
三相ベクトル処理部118、単独運転検出部120、同
期検出部121などを備えて構成されている。As shown in FIG. 2, the control device 11 has an A / D converter 110 for converting the detection outputs (analog amount signals) of the current detector 13, the voltage detectors 14, 15 into digital signals, and current information. Arithmetic unit 111, comparison unit 112, voltage information arithmetic unit 114, comparison unit 115, preprocessing determination unit 117,
The three-phase vector processing unit 118, the islanding operation detection unit 120, the synchronization detection unit 121, and the like are provided.
【0029】上記構成による制御装置11において瞬時
電圧低下の検出を行うに際しては、検出器13の検出に
よる各相の電流Iu、Iv、Iw、電圧検出器14の検
出による各相の電圧Vsu、Vsv、Vsw、電圧検出
器15の検出による各相の電圧Vgu、Vgv、Vgw
をそれぞれA/D変換部110で指定のサンプリング周
波数にしたがってサンプリングするとともにホールド
し、電圧情報演算部114で各相の電圧Vsu、Vs
v、VswおよびVgu、Vgv、Vgwの瞬時値を用
いて各相の電圧低下量ΔVの計算を行う。When detecting the instantaneous voltage drop in the control device 11 having the above configuration, the currents Iu, Iv, Iw of the respective phases detected by the detector 13 and the voltages Vsu, Vsv of the respective phases detected by the voltage detector 14 are detected. , Vsw, and the voltages Vgu, Vgv, Vgw of each phase detected by the voltage detector 15.
Are sampled and held by the A / D converter 110 according to the designated sampling frequency, and the voltage information calculator 114 holds the voltages Vsu and Vs of the respective phases.
The voltage drop amount ΔV of each phase is calculated using the instantaneous values of v, Vsw and Vgu, Vgv, Vgw.
【0030】次に、比較部115で電圧情報演算部14
で算出された各相の電圧低下量ΔVと判定値ε1とを比
較し、いずれかの相の電圧低下量ΔVが判定値ε1より
も下回っているときには、いずれかの相の電圧に異常が
あるとして異常検出信号を前処理判定部117に出力す
る。すなわち電圧情報演算部114、比較部115は電
圧異常検出手段として構成されている。このとき同時
に、各相の電流Iu、Iv、Iwの瞬時値を用いて電流
情報演算部111において各相の電流の絶対値あるいは
時間変化率の算出が行われ、この算出結果と判定値ε2
とが比較部112において行われ、いずれかの算出結果
が判定値ε2を超えているときには電流に異常が生じた
として異常検出信号を前処理判定部117に出力する。
すなわち、電流情報演算部111、比較部112は電流
異常検出手段として構成されている。Next, the comparator 115 outputs the voltage information calculator 14
The voltage drop amount ΔV of each phase calculated in step 1 is compared with the determination value ε1. When the voltage drop amount ΔV of any phase is lower than the determination value ε1, the voltage of any phase is abnormal. The abnormality detection signal is output to the preprocessing determination unit 117 as. That is, the voltage information calculation unit 114 and the comparison unit 115 are configured as voltage abnormality detection means. At this time, at the same time, the current information calculation unit 111 calculates the absolute value of the current of each phase or the time change rate using the instantaneous values of the currents Iu, Iv, and Iw of each phase.
Is performed in the comparison unit 112, and when any of the calculation results exceeds the determination value ε2, it is determined that an abnormality has occurred in the current and an abnormality detection signal is output to the preprocessing determination unit 117.
That is, the current information calculation unit 111 and the comparison unit 112 are configured as current abnormality detection means.
【0031】次に、前処理判定部117において、比較
部112または比較部115から異常検出信号が入力さ
れたとき、すなわち、いずれか一方の比較部から、入力
信号が基準値を逸脱しているとの比較結果が出力された
ときには、所定のゲインa(>1)を出力する。これに
より異常判定のしきい値ε3にゲインaが乗算され、異
常判定のしきい値ε3を大きくして検出感度を高めるた
めの補正が行われる。すなわち前処理判定部117は異
常判定のしきい値を補正する補正手段として構成されて
いる。Next, in the preprocessing determination section 117, when an abnormality detection signal is input from the comparison section 112 or the comparison section 115, that is, the input signal deviates from the reference value from either one of the comparison sections. When the comparison result with is output, a predetermined gain a (> 1) is output. As a result, the threshold value ε3 for abnormality determination is multiplied by the gain a, and correction is performed to increase the threshold value ε3 for abnormality determination and increase the detection sensitivity. That is, the preprocessing determination unit 117 is configured as a correction unit that corrects the threshold value for abnormality determination.
【0032】一方、三相ベクトル処理部118では、以
下のような処理が行われる。A/D変換部110でサン
プリングされた電力系統4側の電圧Vsu、Vsv、V
swを用いて三相/二相変換部1181で、次の(1)
式および(2)式により合成電圧ベクトルVα、Vβを
求め、これらを絶対値計算部1182でベクトル合成し
て絶対値|Vαβ|(一定の直流分となる電圧値)を算
出する。On the other hand, the three-phase vector processing unit 118 performs the following processing. The voltages Vsu, Vsv, V on the side of the power system 4 sampled by the A / D converter 110
In the three-phase / two-phase conversion unit 1181 using sw, the following (1)
The combined voltage vectors Vα and Vβ are obtained from the equations and the expression (2), and the absolute value calculation unit 1182 vector-combines them to calculate an absolute value | Vαβ | (voltage value corresponding to a constant DC component).
【0033】[0033]
【数1】 [Equation 1]
【0034】[0034]
【数2】
このあと、絶対値計算部1182の算出による絶対値と
異常判定のしきい値とを瞬時電圧低下判定部1183で
比較し、この比較により瞬時電圧低下の有無を判定し、
瞬時電圧低下が発生したときには瞬時電圧低下判定部1
183から遮断器12に対して遮断指令が出力され、遮
断器12が遮断されるようになっている。すなわち、三
相/二相変換部1181、絶対値計算部1182は絶対
値算出手段として、瞬時電圧低下判定部1183は瞬時
電圧低下判定手段および遮断指令出力手段として構成さ
れている。[Equation 2] After that, the absolute value calculated by the absolute value calculation unit 1182 and the threshold value for abnormality determination are compared by the instantaneous voltage drop determination unit 1183, and the presence or absence of the instantaneous voltage drop is determined by this comparison.
When an instantaneous voltage drop occurs, the instantaneous voltage drop determining unit 1
A disconnection command is output from the circuit breaker 183 to the circuit breaker 12, and the circuit breaker 12 is disconnected. That is, the three-phase / two-phase conversion unit 1181 and the absolute value calculation unit 1182 are configured as an absolute value calculation unit, and the instantaneous voltage drop determination unit 1183 is configured as an instantaneous voltage drop determination unit and a cutoff command output unit.
【0035】ここで、本実施形態においては、合成ベク
トルの絶対値|Vαβ|に対する判定値(異常判定のし
きい値)ε3に、各相の電圧、電流の瞬時値による前処
理判定部117から出力される所定のゲインa(>1)
を乗じるに際して、いずれかの相の電圧・電流に異常を
検出したときのみ絶対値|Vαβ|に対する判定値ε3
を大きくして検出感度を上げるようにしている。このよ
うにすることで、検出時間は短いが、波形歪み、周波数
変動などで誤検出しやすい各相ごとの瞬時値による検出
と、外乱には強いが故障の様相によっては検出に時間を
要する三相の合成ベクトル処理による検出の短所を補い
ながら、互いの長所を活かすことができる。結果とし
て、本実施形態による補正処理を行うことで、ノイズ処
理、故障継続性判定処理などの複雑な処理を加えること
なく、外乱に強く且つ所定の時間内で瞬時電圧低下を高
精度に検出することができる。Here, in the present embodiment, the preprocessing determination unit 117 based on the instantaneous values of the voltage and current of each phase is used as the determination value (threshold value for abnormality determination) ε3 for the absolute value | Vαβ | of the combined vector. Output predetermined gain a (> 1)
When multiplying by, a judgment value ε3 for the absolute value | Vαβ |
To increase the detection sensitivity. By doing so, although the detection time is short, detection is performed by the instantaneous value for each phase that is easily erroneously detected due to waveform distortion, frequency fluctuation, and the like. It is possible to make use of the advantages of each other while compensating for the disadvantages of detection by the combined vector processing of phases. As a result, by performing the correction processing according to the present embodiment, it is possible to detect an instantaneous voltage drop with high accuracy against disturbance and within a predetermined time without adding complicated processing such as noise processing and failure continuity determination processing. be able to.
【0036】次に、瞬時電圧低下の具体的な検出動作を
図3にしたがって説明する。まず、電力系統4で一線地
絡故障が発生したときのように、三相電圧低下の割合に
ばらつきがある場合の例について説明する。図3(a)
に示すように、V相で一線地絡故障が発生した場合、
(b)に示すように、電力系統4側の電圧Vsu、Vs
v、Vswの波形のうち、V相の電圧が低下し、V相の
電圧低下率が最も早く大きくなる。すなわち、V相の電
圧が低下すると、次の(3)式で定義されるV相の電圧
の瞬時値の低下率ΔVsviは、(b)に示すように、
急激に低下する。Next, a concrete detecting operation of the instantaneous voltage drop will be described with reference to FIG. First, an example will be described in which the rate of three-phase voltage drop varies, such as when a one-line ground fault occurs in the power system 4. Figure 3 (a)
As shown in, when a one-line ground fault occurs in the V phase,
As shown in (b), the voltages Vsu, Vs on the side of the power system 4
Among the waveforms of v and Vsw, the V-phase voltage decreases, and the V-phase voltage decrease rate becomes the fastest and the largest. That is, when the V-phase voltage decreases, the decrease rate ΔVsvi of the instantaneous value of the V-phase voltage defined by the following equation (3) is as shown in (b):
Falls sharply.
【0037】[0037]
【数3】
ここで、添字iはA/D変換部110によるサンプリン
グ時刻、nは一周期のサンプリング点数である。(3)
式のΔVsviと判定値ε1とを比較部115で比較
し、(b)に示すように、所定のサンプリング回数以上
連続してΔVsvi<ε1が成立したときには、V相の
電圧低下の可能性が有りとする比較結果、すなわち、異
常検出信号が前処理判定部117に出力される。比較部
115の比較演算により電圧低下の可能性があるとの判
定結果が得られたときには、(c)に示すように、三相
/二相変換部1181および絶対値計算部1182の演
算で得られた合成電圧ベクトルの絶対値|Vαβ|に対
する判定値ε3に対してゲインa(>1)を乗算し、こ
の判定値ε3を大きくして検出感度を上げるための補正
が行われる。[Equation 3] Here, the subscript i is the sampling time by the A / D conversion unit 110, and n is the number of sampling points in one cycle. (3)
The comparing unit 115 compares ΔVsvi in the equation with the determination value ε1 and, as shown in (b), when ΔVsvi <ε1 is satisfied continuously for a predetermined number of sampling times or more, there is a possibility that the voltage of the V phase may drop. The comparison result, that is, the abnormality detection signal is output to the preprocessing determination unit 117. When the comparison operation of the comparison unit 115 obtains a determination result that there is a possibility of a voltage drop, it is obtained by the operations of the three-phase / two-phase conversion unit 1181 and the absolute value calculation unit 1182 as shown in (c). The determination value ε3 for the absolute value | Vαβ | of the obtained combined voltage vector is multiplied by the gain a (> 1), and the determination value ε3 is increased to correct the detection sensitivity.
【0038】このような補正処理を行うことで、三相の
電圧低下のばらつきのために、絶対値|Vαβ|が脈動
し、且つ電圧低下量を検出するのに十分でない場合にお
いても、従来の三相/二相変換のみによる検出方法に比
べて、検出時間を短縮することができる。また、各相の
瞬時値と合成電圧ベクトルの組合わせによるもので、各
相ごとの瞬時値のみを用いた検出時に起こり得る誤検出
の問題を回避することもできる。By carrying out such a correction process, even if the absolute value | Vαβ | pulsates due to the variation in the three-phase voltage drop and it is not sufficient to detect the amount of voltage drop, the conventional method is used. The detection time can be shortened as compared with the detection method using only three-phase / two-phase conversion. In addition, since the combination of the instantaneous value of each phase and the combined voltage vector is used, it is possible to avoid the problem of erroneous detection that may occur at the time of detection using only the instantaneous value of each phase.
【0039】次に、瞬時電圧低下を検出するに際して、
電流情報演算部111、電圧情報演算部114、比較部
112、115における具体的な処理内容を図4にした
がって説明する。まず、瞬時電圧低下の各相ごとの瞬時
値処理を行うに際して、電圧低下率によって瞬時電圧低
下を検出するに際しては、(a)に示すように、電力系
統4側および分散型電源5側の電圧の瞬時値Vsui、
Vsvi、VswiおよびVgui、Vgvi、Vgw
iを用いて電圧情報演算部114において各相の電圧低
下率を求め、各算出値をそれぞれ判定値ε1と比較し、
電力系統4側および分散型電源5側の少なくとも1つの
相に関する電圧低下率が同時に所定のサンプリング回数
以上連続して判定値ε1を下回ったときには、電圧異常
が生じたとして異常検出信号が比較部115から前処理
判定部117に出力される。すなわち電圧情報演算部1
14、比較部115は各相の電圧降下量(電圧低下率)
のうちいずれかの相の電圧降下量が電圧判定値(判定値
ε1)以下になったときに異常を検出する電圧異常検出
手段として構成されている。Next, in detecting the instantaneous voltage drop,
Specific processing contents of the current information calculation unit 111, the voltage information calculation unit 114, and the comparison units 112 and 115 will be described with reference to FIG. First, when performing the instantaneous value processing for each phase of the instantaneous voltage drop, when detecting the instantaneous voltage drop by the voltage drop rate, as shown in (a), the voltage of the power system 4 side and the distributed power source 5 side is The instantaneous value of Vsui,
Vsvi, Vswi and Vgui, Vgvi, Vgw
Using i, the voltage information calculation unit 114 obtains the voltage drop rate of each phase, compares each calculated value with the determination value ε1,
When the voltage drop rate for at least one phase on the power system 4 side and the distributed power source 5 side simultaneously falls below the judgment value ε1 for a predetermined number of sampling times or more at the same time, it is determined that a voltage abnormality has occurred and the abnormality detection signal indicates that the comparator 115 Is output to the preprocessing determination unit 117. That is, the voltage information calculation unit 1
14, the comparison unit 115 is the voltage drop amount of each phase (voltage drop rate)
The voltage abnormality detecting means is configured to detect an abnormality when the voltage drop amount of one of the phases becomes equal to or lower than the voltage determination value (determination value ε1).
【0040】次に、瞬時電圧低下を電流の絶対値によっ
て検出する場合には、(b)に示すように、各相の電流
の瞬時値Iui、Ivi、Iwiから電流情報演算部1
11でそれぞれの絶対値を算出し、各算出値と判定値ε
2とをそれぞれ比較し、少なくとも1つの相の算出値が
所定のサンプリング回数以上連続して判定値ε2を超え
ていると比較部112において判定されたときには、比
較部112から前処理判定部117に対して電流の異常
が生じたとして異常検出信号が出力される。すなわち電
流情報演算部111、比較部112は電流異常検出手段
として構成されている。Next, in the case of detecting the instantaneous voltage drop by the absolute value of the current, as shown in (b), the current information calculation unit 1 is calculated from the instantaneous values Iui, Ivi, Iwi of the currents of the respective phases.
Each absolute value is calculated in 11, and each calculated value and the judgment value ε
2 is compared with each other, and when the comparison unit 112 determines that the calculated value of at least one phase continuously exceeds the determination value ε2 for a predetermined number of sampling times or more, the comparison unit 112 causes the preprocessing determination unit 117 to On the other hand, an abnormality detection signal is output because an abnormality in the current has occurred. That is, the current information calculation unit 111 and the comparison unit 112 are configured as current abnormality detection means.
【0041】また、電流の時間変化により瞬時電圧低下
を検出する場合には、(c)に示すように、各相の電流
の瞬時値Iui、Ivi、Iwiを用いて電流情報演算
部111でそれぞれの時間変化率を算出し、各算出値と
判定値ε2とをそれぞれ比較し、少なくとも1つの算出
値が所定のサンプリング回数以上連続して判定値ε2を
超えているときには、電流に異常が生じたとして、異常
検出信号が比較部112から前処理判定部117に出力
される。すなわち、電流情報演算部111、比較部11
2は電流異常検出手段として構成されている。When an instantaneous voltage drop is detected by the time change of the current, as shown in (c), the current information calculator 111 uses the instantaneous values Iui, Ivi, Iwi of the currents of the respective phases. The time change rate of is calculated, each calculated value is compared with the judgment value ε2, and when at least one calculated value exceeds the judgment value ε2 continuously for a predetermined number of sampling times or more, an abnormality occurs in the current. As a result, the abnormality detection signal is output from the comparison unit 112 to the preprocessing determination unit 117. That is, the current information calculation unit 111 and the comparison unit 11
Reference numeral 2 is configured as a current abnormality detecting means.
【0042】なお、瞬時電圧低下を検出するに際して
は、前処理判定に用いる各相の瞬時値による処理とし
て、図4(a)の電圧低下量の演算処理と(b)あるい
は(c)の電流の演算処理とを併用しても良いし、
(a)の電圧低下量の演算処理だけでも良い。When detecting the instantaneous voltage drop, as the process based on the instantaneous value of each phase used for the preprocessing determination, the voltage drop amount calculation process of FIG. 4A and the current of FIG. May be used together with the calculation processing of
Only the calculation process of the voltage drop amount of (a) may be performed.
【0043】次に、単独運転を検出するに際しては、図
2に示す受動方式の単独運転検出部120が用いられ
る。単独運転検出部120は周波数変化率演算部120
1、単独運転判定部1202を備えて構成されている。
周波数変化率演算部1201では、まず、電圧情報演算
部114において、上述したように、各相の瞬時電圧低
下の検出に必要な各相の電圧低下量を検出する過程で検
出しておいた、分散型電源5側の電圧Vgの波形の零ク
ロス点の時刻tgu、tgv、tgwを用いて周波数を
算出する。次に、(4)式で定義される周波数変化率Δ
fを計算する。Next, when detecting the isolated operation, the passive type isolated operation detecting section 120 shown in FIG. 2 is used. The islanding operation detection unit 120 is a frequency change rate calculation unit 120.
1. It is configured by including the islanding operation determination unit 1202.
In the frequency change rate calculation unit 1201, first, in the voltage information calculation unit 114, as described above, it is detected in the process of detecting the voltage drop amount of each phase necessary for detecting the instantaneous voltage drop of each phase, The frequency is calculated using the times tgu, tgv, and tgw at the zero cross points of the waveform of the voltage Vg on the distributed power supply 5 side. Next, the frequency change rate Δ defined by equation (4)
Calculate f.
【0044】[0044]
【数4】
ここで、f(Hz)基準周波数で、例えば現在のサンプ
リング時刻から0.5〜1s前の時間区間の平均値とす
る。f1(Hz)は現在の時刻における周波数で、例え
ば、現在のサンプリング時刻から3サイクル前の時間区
間平均値とする。[Equation 4] Here, at the f (Hz) reference frequency, for example, an average value of a time section 0.5 to 1 second before the current sampling time is used. f1 (Hz) is the frequency at the current time, and is, for example, the time interval average value three cycles before the current sampling time.
【0045】(4)式の周波数変化率Δfを各相ごとに
算出し、この算出結果と判定値ε4とを判定部1202
でそれぞれ比較し、少なくとも1つの算出値が判定値ε
4を超えているときには、単独運転と判定し、遮断器1
2に対して遮断指令を出力し遮断器12を開放する。す
なわち単独運転検出部120は単独運転検出手段ととも
に遮断指令出力手段として構成されている。The frequency change rate Δf of the equation (4) is calculated for each phase, and the calculation result and the judgment value ε4 are judged by the judgment unit 1202.
And at least one calculated value is the judgment value ε.
When it exceeds 4, it is judged to be an independent operation and the circuit breaker 1
A disconnection command is output to 2 to open the circuit breaker 12. That is, the islanding operation detection unit 120 is configured as an interruption command output means together with the islanding operation detection means.
【0046】単独運転を検出するに際しては、受動方式
による単独運転検出部120とともに、図5に示すよう
に、能動方式による単独運転検出部122を用いること
ができる。この能動方式による単独運転検出部122に
おいては、発電設備の制御系や外部の回路などにより、
常時何らかの変動を与えておき、単独運転時に顕著にな
るこの変動を利用して単独運転を検出する方式が採用さ
れている。In detecting the islanding operation, the islanding operation detecting section 120 of the active system can be used together with the islanding operation detecting section 120 of the active system as shown in FIG. In the islanding detection unit 122 based on this active method, the control system of the power generation equipment, an external circuit, etc.
A method is used in which some kind of fluctuation is always given and the fluctuation is noticeable during the independent operation to detect the independent operation.
【0047】図5において、電圧変動信号発生部122
4は、常時所定の変動信号Vcntを分散型電源5の制
御装置52へ送り続ける。周波数変化率演算部1221
では、受動方式のときと同様に、分散型電源5側の電圧
Vgの波形の零クロス点の時刻tgu、tgv、tgw
を用いて周波数を算出したあと、(4)式を用いて各相
の周波数変化率Δfを算出する。判定部1222では、
各相の周波数変化率Δfと2つの判定値ε4、ε5とを
それぞれ比較する。まず、各相の周波数変化率Δfのう
ち少なくとも1つがε4<Δf<ε5を満たすならばゲ
インbを出力する。このゲインbは電圧変動信号発生器
1224から送られる変動信号に乗算され、分散型電源
5の制御装置52への変動指令値を大きくする。また、
少なくとも、1つの相に関する算出値がε5<Δfを満
たすときには、母線連絡用遮断器12に対して遮断指令
を出力する。In FIG. 5, the voltage fluctuation signal generator 122 is shown.
4 continuously sends a predetermined fluctuation signal Vcnt to the controller 52 of the distributed power source 5. Frequency change rate calculation unit 1221
Then, as in the case of the passive method, the times tgu, tgv, and tgw of the zero crossing point of the waveform of the voltage Vg on the distributed power supply 5 side.
After calculating the frequency using, the frequency change rate Δf of each phase is calculated using the equation (4). In the determination unit 1222,
The frequency change rate Δf of each phase is compared with the two determination values ε4 and ε5, respectively. First, if at least one of the frequency change rates Δf of the respective phases satisfies ε4 <Δf <ε5, the gain b is output. This gain b is multiplied by the fluctuation signal sent from the voltage fluctuation signal generator 1224 to increase the fluctuation command value to the control device 52 of the distributed power supply 5. Also,
At least when the calculated value for one phase satisfies ε5 <Δf, the shutoff command is output to the busbar breaker 12.
【0048】このように、単独運転の検出に、周波数変
化率を用いれば、太陽電池、燃料電池、マイクロガスタ
ービンのように、インバータを介して連系される分散型
電源にも、回転機系の分散型電源にも適用可能である。
なお、本実施形態では、単独運転の検出を図2に示す受
動方式と図5に示す能動方式について述べたが、これら
に限定されるものではなく、他の方法を採用することも
できる。As described above, if the frequency change rate is used to detect the islanding operation, the distributed power sources interconnected via the inverter, such as the solar cell, the fuel cell, and the micro gas turbine, can be used in the rotating machine system. It can also be applied to the distributed power sources of.
In the present embodiment, the detection of the islanding operation has been described with respect to the passive method shown in FIG. 2 and the active method shown in FIG. 5, but the detection is not limited to these, and other methods can be adopted.
【0049】また、遮断器12を遮断したあと同期投入
するに際しては、同期検出部121によって同期検出が
行われる。この同期検出部121は位相差演算部121
1、同期判定部1212を備えて構成されており、遮断
器12の投入に必要な系統側電圧Vsと分散型電源側の
電圧Vgの同期検出が行われる。まず位相差演算部12
11においては、各相の電圧情報演算部114で求めら
れた各相の系統側電圧Vsの波形の零クロス点と、分散
型電源側電圧Vgの波形の零クロス点の時間差から位相
差|Δθ|を計算する。同期判定部121では、位相差
演算部1211の算出による位相差|Δθ|と判定値ε
6とを比較し、|Δθ|<ε6を満たしているときに
は、同期と判定し、遮断器12に対して投入指令を出力
する。When the circuit breaker 12 is turned off and then the synchronization is turned on, the synchronization detector 121 detects the synchronization. The synchronization detector 121 is a phase difference calculator 121.
1. The system includes a synchronization determination unit 1212, and the system side voltage Vs required to turn on the circuit breaker 12 and the distributed power source side voltage Vg are synchronously detected. First, the phase difference calculation unit 12
In 11, the phase difference | Δθ is calculated from the time difference between the zero cross point of the waveform of the system side voltage Vs of each phase and the zero cross point of the waveform of the distributed power supply side voltage Vg obtained by the voltage information calculation unit 114 of each phase. Calculate |. In the synchronization determination unit 121, the phase difference | Δθ | calculated by the phase difference calculation unit 1211 and the determination value ε
6 and when | Δθ | <ε6 is satisfied, it is determined to be synchronous and a closing command is output to the circuit breaker 12.
【0050】このように、本実施形態においては、連系
保護システムの制御アルゴリズムをマイコンなどの演算
処理装置にプログラミングし、これを電源、A/D変換
器、メモリとともに単一のプリント基板に設置して制御
基板を構成し、この制御基板を制御装置11に組み込む
こととしている。As described above, in the present embodiment, the control algorithm of the interconnection protection system is programmed in the arithmetic processing unit such as a microcomputer, and this is installed on the single printed circuit board together with the power source, the A / D converter and the memory. Then, the control board is configured, and this control board is incorporated in the control device 11.
【0051】次に、本発明の他の実施形態を図6にした
がって説明する。本実施形態は、分散型電源設備の制御
装置52に瞬時電圧低下および単独運転を検出する機能
を付加するとともに、分散型電源の運転状態を制御する
分散型電源制御手段としての機能を付加して連系保護シ
ステムを構成したものであり、他の構成は図1のものと
同様である。Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, a function for detecting an instantaneous voltage drop and an isolated operation is added to the control device 52 of the distributed power supply facility, and a function as a distributed power supply control means for controlling the operating state of the distributed power supply is added. This is a configuration of the interconnection protection system, and other configurations are similar to those of FIG.
【0052】分散型電源の制御装置52は、電源制御部
521と連系保護制御部522を備えて構成されてお
り、連系保護制御部522には、前記実施形態で用いた
制御アルゴリズムに関する情報を搭載した制御基板が採
用されている。電源制御部521は、連系保護制御部5
22から出力される電圧変動指令にしたがって発電装置
51による運転状態を制御するように構成されている。The distributed power supply control device 52 comprises a power supply control unit 521 and an interconnection protection control unit 522. The interconnection protection control unit 522 has information regarding the control algorithm used in the above embodiment. A control board equipped with is used. The power supply control unit 521 is the interconnection protection control unit 5
It is configured to control the operating state of the power generation device 51 according to the voltage fluctuation command output from 22.
【0053】本実施形態においては、連系保護制御部5
22に前記実施形態と同様な機能を持たせているため、
前記実施形態と同様な効果を得ることができる。In this embodiment, the interconnection protection control unit 5
22 has the same function as that of the above embodiment,
The same effect as that of the above-described embodiment can be obtained.
【0054】なお、電源制御部521の制御基板内に、
図2の制御アルゴリズムをプログラミングし、且つこの
制御基板に電流検出器13、電圧検出器14、15の入
力部を追加して、電源制御部521に連系保護制御部5
22の機能を組み込むことも可能である。In the control board of the power supply controller 521,
The control algorithm of FIG. 2 is programmed, and the input parts of the current detector 13 and the voltage detectors 14 and 15 are added to this control board, and the power supply controller 521 is connected to the interconnection protection controller 5.
It is also possible to incorporate 22 functions.
【0055】上述したように、前記各実施形態によれ
ば、瞬時電圧低下および単独運転の検出に伴う演算処理
の共有化を図ることで、単一の制御装置11、52に上
記の機能を集約することが可能となるため、専用の瞬時
電圧低下検出装置や単独運転検出装置および転送遮断装
置を設置する必要がなくなる。したがって、設備投資を
増加することなく、また保護システムの構成や制御を複
雑化することなく、従来と同様な保護機能を得ることが
できる。また保護装置間の通信線を削減できるため、制
御の応答性/信頼性も向上する。As described above, according to each of the above-described embodiments, the functions described above are integrated in the single control device 11, 52 by sharing the arithmetic processing associated with the detection of the instantaneous voltage drop and the isolated operation. Therefore, it is not necessary to install a dedicated instantaneous voltage drop detection device, an islanding operation detection device, and a transfer interruption device. Therefore, a protection function similar to the conventional one can be obtained without increasing equipment investment and without complicating the configuration and control of the protection system. Further, since the communication lines between the protection devices can be reduced, the control response / reliability is also improved.
【0056】さらに、瞬時電圧低下の検出方法において
は、各相の電圧、電流の瞬時値による検出と、三相/二
相変化による合成電圧ベクトルを用いた検出を併用し、
且つ瞬時値による検出結果を用いて合成電圧ベクトルの
ための異常判定値を補正するようにしているため、波形
歪み、周波数変動などの擾乱の影響を受けずに、且つ検
出時間を増加させることなく信頼性を向上させることが
できる。Furthermore, in the method of detecting the instantaneous voltage drop, the detection by the instantaneous value of the voltage and current of each phase and the detection by the combined voltage vector by the three-phase / two-phase change are used together,
Moreover, since the abnormality determination value for the combined voltage vector is corrected using the detection result based on the instantaneous value, it is not affected by the disturbance such as the waveform distortion and the frequency fluctuation, and the detection time is not increased. The reliability can be improved.
【0057】[0057]
【発明の効果】以上説明したように、本発明によれば、
単一の制御手段により、瞬時電圧低下および単独運転を
検出し、この検出結果にしたがって母線連絡用遮断器を
遮断する制御を行い、瞬時電圧低下のための演算処理と
単独運転検出のための演算処理の共有化を図るようにし
たため、演算量を低減することができ、演算処理を円滑
に行うことができる。また、本発明によれば、系統側電
圧検出器の検出出力を三相/二相変換して合成電圧ベク
トルの絶対値を算出し、この絶対値と異常判定のしきい
値とを比較して瞬時電圧低下の発生の有無を判定すると
きに、電圧異常検出手段または電流異常検出手段の検出
出力により異常判定のしきい値を補正するようにしてい
るため、ノイズ処理、故障継続性判定などの複雑な処理
を加えることなく、外乱に強く且つ所定の時間内で瞬時
電圧低下を高精度に検出することができる。As described above, according to the present invention,
The single control means detects the instantaneous voltage drop and the islanding operation, and performs the control to shut off the busbar circuit breaker according to the detection result. The calculation process for the instantaneous voltage drop and the computation for the islanding operation detection. Since the processing is shared, the calculation amount can be reduced and the calculation processing can be smoothly performed. Further, according to the present invention, the detection output of the system side voltage detector is subjected to three-phase / two-phase conversion to calculate the absolute value of the combined voltage vector, and the absolute value is compared with the abnormality determination threshold value. When determining whether or not an instantaneous voltage drop has occurred, the threshold for abnormality determination is corrected by the detection output of the voltage abnormality detection means or the current abnormality detection means, so noise processing, failure continuity determination, etc. It is possible to detect an instantaneous voltage drop with high accuracy against a disturbance and within a predetermined time without adding complicated processing.
【図1】本発明の一実施形態を示す分散型電源設備の連
系保護システムのブロック構成図である。FIG. 1 is a block configuration diagram of an interconnection protection system for distributed power supply equipment showing an embodiment of the present invention.
【図2】瞬時電圧低下化と単独運転を検出するアルゴリ
ズムを説明するためのブロック構成図である。FIG. 2 is a block configuration diagram for explaining an algorithm for detecting instantaneous voltage drop and islanding.
【図3】瞬時電圧低下の検出方法を説明するための波形
図である。FIG. 3 is a waveform diagram for explaining a method of detecting an instantaneous voltage drop.
【図4】瞬時電圧低下の具体的アルゴリズムを説明する
ためのブロック構成図である。FIG. 4 is a block configuration diagram for explaining a specific algorithm for instantaneous voltage drop.
【図5】能動方式による単独運転検出方法を説明するた
めのブロック構成図である。FIG. 5 is a block diagram for explaining an islanding operation detection method by an active method.
【図6】本発明の他の実施形態を示す連系保護システム
のブロック構成図である。FIG. 6 is a block configuration diagram of an interconnection protection system showing another embodiment of the present invention.
1 連系保護システム 2、3 負荷 4 電力系統 5 分散型電源設備 6、7、8、9 遮断器 10 受電用変圧器 11 制御装置 110 A/D変換部 111 電流情報演算部 112 電圧情報演算部 113 三相ベクトル処理部 114 電圧情報演算部 115 単独運転検出部 117 前処理判定部 12 母線連絡用遮断器 13 電力検出器 14、15 電圧検出器 1 interconnection protection system A few loads 4 power system 5 Distributed power equipment 6, 7, 8, 9 circuit breaker 10 Power receiving transformer 11 Control device 110 A / D converter 111 Current information calculation unit 112 Voltage information calculator 113 three-phase vector processing unit 114 voltage information calculator 115 Independent operation detector 117 Preprocessing determination unit 12 Busbar breaker 13 Power detector 14, 15 Voltage detector
───────────────────────────────────────────────────── フロントページの続き (72)発明者 有田 浩 茨城県日立市大みか町七丁目2番1号 株 式会社日立製作所電力・電機開発研究所内 (72)発明者 樋口 幹祐 茨城県日立市国分町一丁目1番1号 株式 会社日立製作所電機システム事業部内 Fターム(参考) 5G004 AA01 AB01 BA08 DA01 DC14 EA04 5G066 HA02 HA04 HA11 HB02 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Hiroshi Arita 2-12-1 Omika-cho, Hitachi-shi, Ibaraki Prefecture Ceremony Company Hitachi, Ltd. (72) Inventor Mikisuke Higuchi 1-1-1 Kokubuncho, Hitachi-shi, Ibaraki Stock Hitachi, Ltd. Electric Systems Division F-term (reference) 5G004 AA01 AB01 BA08 DA01 DC14 EA04 5G066 HA02 HA04 HA11 HB02
Claims (9)
線に設置されて前記母線を指令に応じて開閉する母線連
絡用遮断器と、前記遮断器より電力系統側の母線電圧を
検出する系統側電圧検出器と、前記遮断器より分散型電
源側の母線電圧を検出する分散電源側電圧検出器と、前
記母線の通過電流を検出する電流検出器と、前記系統側
電圧検出器と前記分散電源側電圧検出器および前記電流
検出器の検出出力を基に前記電力系統の異常の有無を判
定し、この判定結果に従った前記遮断器の遮断・投入を
制御する制御手段とを備え、前記制御手段は、前記系統
側電圧検出器の検出電圧と前記電流検出器の検出電流を
演算処理して瞬時電圧低下を検出する瞬時電圧低下検出
手段と、前記分散型電源側電圧検出器の検出電圧の周波
数変化率から単独運転を検出する単独運転検出手段と、
前記瞬時電圧低下検出手段の検出出力または前記単独運
転検出手段の検出出力に応答して前記遮断器に対して遮
断指令を出力する遮断指令出力手段とを含んで構成され
てなる分散型電源設備の連系保護システム。1. A busbar connecting circuit breaker installed on a busbar connecting a three-phase power system and a distributed power source to open and close the busbar according to a command, and a busbar voltage on the power system side of the circuit breaker. A system side voltage detector, a distributed power source side voltage detector for detecting a bus voltage on the distributed power source side from the circuit breaker, a current detector for detecting a passing current of the bus bar, and the system side voltage detector A control means for determining whether or not there is an abnormality in the power system based on the detection outputs of the distributed power source side voltage detector and the current detector, and controlling the interruption / closing of the circuit breaker according to the determination result. The control means calculates the detection voltage of the system side voltage detector and the detection current of the current detector to detect an instantaneous voltage drop, and detects the instantaneous voltage drop; and the distributed power supply side voltage detector. Single operation based on the frequency change rate of the detected voltage An independent operation detecting means for detecting a rotation,
A distributed power supply facility comprising: a disconnection command output unit that outputs a disconnection command to the circuit breaker in response to a detection output of the instantaneous voltage drop detection unit or a detection output of the islanding operation detection unit. Interconnection protection system.
保護システムにおいて、前記制御手段は、前記系統側電
圧検出器の検出電圧と前記分散電源側電圧検出器の検出
電圧との位相差を検出する位相差検出手段と、前記位相
差検出手段の検出出力により同期タイミングを判定する
同期判定手段と、前記同期判定手段から同期タイミング
であるとの判定結果が出力されたときに前記遮断器に対
して投入指令を出力する投入指令出力手段とを含んで構
成されてなることを特徴とする分散型電源設備の連系保
護システム。2. The interconnected protection system for distributed power supply equipment according to claim 1, wherein the control means sets the level of the detected voltage of the system side voltage detector and the detected voltage of the distributed power source side voltage detector. Phase difference detection means for detecting a phase difference, synchronization determination means for determining the synchronization timing based on the detection output of the phase difference detection means, and the shutoff when the synchronization determination means outputs a determination result that the synchronization timing is reached. A connection protection system for distributed power equipment, comprising a closing command output means for outputting a closing command to the power supply.
備の連系保護システムにおいて、前記制御手段は、前記
分散型電源の運転状態を制御する分散型電源制御手段を
含んで構成されてなることを特徴とする分散型電源設備
の連系保護システム。3. The interconnection protection system for distributed power supply equipment according to claim 1, wherein the control means includes a distributed power supply control means for controlling an operating state of the distributed power supply. An interconnected protection system for distributed power supply facilities.
項に記載の分散型電源設備の連系保護システムにおい
て、前記瞬時電圧低下検出手段は、前記系統側電圧検出
器の検出出力を三相/二相変換して合成電圧ベクトルの
絶対値を算出する絶対値算出手段と、前記絶対値算出手
段の算出による絶対値と異常判定のしきい値とを比較し
て瞬時電圧低下の発生の有無を判定する瞬時電圧低下判
定手段と、前記電流検出器の検出による各相の電流を演
算処理して異常を検出する電流異常検出手段と、前記電
流異常検出手段の検出出力により前記異常判定のしきい
値を補正する補正手段とから構成されてなることを特徴
とする分散型電源設備の連系保護システム。4. Any one of claims 1, 2 and 3
In the interconnected protection system for distributed power supply equipment according to the item 1, the instantaneous voltage drop detection means performs a three-phase / two-phase conversion on the detection output of the system side voltage detector to calculate an absolute value of a combined voltage vector. Absolute value calculating means, an instantaneous voltage drop determining means for comparing the absolute value calculated by the absolute value calculating means with a threshold value for abnormality determination to determine whether or not an instantaneous voltage drop has occurred, and the current detector It is composed of a current abnormality detection means for calculating an abnormality by arithmetically processing the current of each phase by the detection, and a correction means for correcting the threshold value of the abnormality determination by the detection output of the current abnormality detection means. A distinctive interconnection protection system for distributed power equipment.
項に記載の分散型電源設備の連系保護システムにおい
て、前記瞬時電圧低下検出手段は、前記系統側電圧検出
器の検出出力を三相/二相変換して合成電圧ベクトルの
絶対値を算出する絶対値算出手段と、前記絶対値算出手
段の算出による絶対値と異常判定のしきい値とを比較し
て瞬時電圧低下の発生の有無を判定する瞬時電圧低下判
定手段と、前記系統側電圧検出器の検出による各相の電
圧を演算処理して異常を検出する電圧異常検出手段と、
前記電圧異常検出手段の検出出力により前記異常判定の
しきい値を補正する補正手段とから構成されてなること
を特徴とする分散型電源設備の連系保護システム。5. Any one of claims 1, 2 and 3
In the interconnected protection system for distributed power supply equipment according to the item 1, the instantaneous voltage drop detection means performs a three-phase / two-phase conversion on the detection output of the system side voltage detector to calculate an absolute value of a combined voltage vector. Absolute value calculating means, an instantaneous voltage drop determining means for comparing the absolute value calculated by the absolute value calculating means with a threshold value for abnormality determination to determine whether or not an instantaneous voltage drop has occurred, and the system side voltage detection Voltage abnormality detection means for calculating the voltage of each phase by detecting the voltage detector to detect abnormality,
An interconnected protection system for distributed power supply equipment, comprising: a correction unit that corrects the threshold value for the abnormality determination based on the detection output of the voltage abnormality detection unit.
項に記載の分散型電源設備の連系保護システムにおい
て、前記瞬時電圧低下検出手段は、前記系統側電圧検出
器の検出出力を三相/二相変換して合成電圧ベクトルの
絶対値を算出する絶対値算出手段と、前記絶対値算出手
段の算出による絶対値と異常判定のしきい値とを比較し
て瞬時電圧低下の発生の有無を判定する瞬時電圧低下判
定手段と、前記系統側電圧検出器の検出による各相の電
圧を演算処理して異常を検出する電圧異常検出手段と、
前記電流検出器の検出による各相の電流を演算処理して
異常を検出する電流異常検出手段と、前記電流異常検出
手段の検出出力または前記電圧異常検出手段の検出出力
により前記異常判定のしきい値を補正する補正手段とか
ら構成されてなることを特徴とする分散型電源設備の連
系保護システム。6. Any one of claims 1, 2 and 3
In the interconnected protection system for distributed power supply equipment according to the item 1, the instantaneous voltage drop detection means performs a three-phase / two-phase conversion on the detection output of the system side voltage detector to calculate an absolute value of a combined voltage vector. Absolute value calculating means, an instantaneous voltage drop determining means for comparing the absolute value calculated by the absolute value calculating means with a threshold value for abnormality determination to determine whether or not an instantaneous voltage drop has occurred, and the system side voltage detection Voltage abnormality detection means for calculating the voltage of each phase by detecting the voltage detector to detect abnormality,
The current abnormality detection means for calculating an abnormality by arithmetically processing the current of each phase detected by the current detector, and the abnormality determination threshold by the detection output of the current abnormality detection means or the detection output of the voltage abnormality detection means. An interconnected protection system for distributed power supply equipment, comprising: a correction unit that corrects a value.
備の連系保護システムにおいて、前記電流異常検出手段
は、前記電流検出器の検出による各相の電流の時間変化
率のうちいずれかの時間変化率が変化率判定値を超えた
ときに異常を検出してなることを特徴とする分散型電源
設備の連系保護システム。7. The interconnection protection system for distributed power supply equipment according to claim 4 or 6, wherein the current abnormality detection means is one of the time change rates of the currents of the respective phases detected by the current detector. An interconnected protection system for distributed power supply equipment, characterized in that an abnormality is detected when the rate of change over time exceeds the rate of change judgment value.
備の連系保護システムにおいて、前記電流異常検出手段
は、前記電流検出器の検出による各相の電流の絶対値の
うちいずれかの絶対値が絶対値判定値を超えたときに異
常を検出してなることを特徴とする分散型電源設備の連
系保護システム。8. The interconnection protection system for distributed power supply equipment according to claim 4 or 6, wherein the current abnormality detection means is one of absolute values of currents of respective phases detected by the current detector. An interconnected protection system for distributed power equipment, which is characterized by detecting an abnormality when the absolute value exceeds an absolute value judgment value.
備の連系保護システムにおいて、前記電圧異常検出手段
は、前記系統側電圧検出器の検出による各相の電圧降下
量のうちいずれかの電圧降下量が電圧判定値以下になっ
たときに異常を検出してなることを特徴とする分散型電
源設備の連系保護システム。9. The interconnection protection system for distributed power supply equipment according to claim 5 or 6, wherein the voltage abnormality detection means is one of voltage drop amounts of the respective phases detected by the system side voltage detector. An interconnected protection system for distributed power supply equipment, characterized in that an abnormality is detected when the amount of voltage drop of the power supply drops below a voltage judgment value.
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JP2013078208A (en) * | 2011-09-30 | 2013-04-25 | Sanyo Electric Co Ltd | Electric power conversion system |
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JP2008035619A (en) * | 2006-07-28 | 2008-02-14 | Omron Corp | Determination method for individual operation of dispersed power system |
JP2013078208A (en) * | 2011-09-30 | 2013-04-25 | Sanyo Electric Co Ltd | Electric power conversion system |
JP2014052180A (en) * | 2012-07-18 | 2014-03-20 | Mitsubishi Electric Corp | Refrigerating cycle apparatus |
KR20150131041A (en) * | 2013-03-13 | 2015-11-24 | 트랜스오션 세드코 포렉스 벤쳐스 리미티드 | Breaker design for power system resiliency |
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