JP6105705B2 - Abnormality detection device and power conditioner for grid interconnection relay - Google Patents
Abnormality detection device and power conditioner for grid interconnection relay Download PDFInfo
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Description
本発明は、系統連系用リレーの異常検出装置、及びパワーコンディショナに関する。 The present invention relates to an abnormality detection device for a grid interconnection relay and a power conditioner.
太陽電池や燃料電池等を備えた分散型直流電源は、商用系統に連系させて使用するために、周波数や電圧を商用系統に適合するように交流電力に変換するパワーコンディショナで構成されている。 A distributed DC power supply equipped with solar cells, fuel cells, etc. is composed of a power conditioner that converts frequency and voltage into AC power so that it can be used in conjunction with commercial systems. Yes.
パワーコンディショナは、太陽電池や燃料電池等で発電された直流電圧を所定の直流電圧値に調整するＤＣ／ＤＣコンバータと、ＤＣ／ＤＣコンバータから出力される直流電力を交流電力に変換するＤＣ／ＡＣインバータと、ＤＣ／ＡＣインバータの出力から高周波成分を除去するＬＣフィルタ等を備えている。 The power conditioner includes a DC / DC converter that adjusts a DC voltage generated by a solar cell, a fuel cell, or the like to a predetermined DC voltage value, and a DC / DC that converts DC power output from the DC / DC converter into AC power. An AC inverter and an LC filter that removes high frequency components from the output of the DC / AC inverter are provided.
太陽電池や燃料電池等に接続されたパワーコンディショナが系統連系運転を行なっている配電線に地絡または短絡事故が発生し、或いは計画停電等によって変電所から配電線への電力の送電が停止した状態、即ち単独運転状態に至った場合に、区分開閉器の動作への影響防止及び配電線等の保全作業時の安全性を確保するために、パワーコンディショナの制御装置によって系統連系用リレーが開成されて当該配電線から分散型電源が解列される。 Power conditioners connected to solar cells, fuel cells, etc. are connected to the grid, and a ground fault or short circuit accident occurs, or planned power outages cause power transmission from the substation to the distribution lines. In order to prevent the influence on the operation of the division switch and to ensure the safety at the maintenance work of the distribution line, etc. in the stopped state, that is, the isolated operation state, the power conditioner control device is connected to the grid. The relay is opened and the distributed power source is disconnected from the distribution line.
そして、パワーコンディショナの制御装置によって商用系統から切り離された自立系統、或いは商用系統とは連系することなく独立した自立系統に接続するべく自立系統用リレーが閉成されることによって、パワーコンディショナは分散型直流電源から交流電源へ変換し、自立系統に交流電力を供給する。 Then, the power conditioner relay is closed so as to be connected to the independent system separated from the commercial system by the control device of the power conditioner or to the independent independent system without being connected to the commercial system. Na converts from a distributed DC power supply to an AC power supply and supplies AC power to a self-supporting system.
パワーコンディショナの制御装置には、系統連系時に商用系統電圧の位相に同期した交流電流がＤＣ／ＡＣインバータから出力されるようにＤＣ／ＡＣインバータを制御する電流制御ブロックと、解列時に自立系統に法定された所定レベルの電圧が出力されるようにＤＣ／ＡＣインバータを制御する電圧制御ブロックを備えている。法定された所定レベルの電圧とは、電気事業法第２６条及び同法施行規則第４４条に規定され、低圧需要家に向けて、標準電圧１００Ｖに対して１０１±６Ｖ、標準電圧２００Ｖに対して２０２±２０Ｖ以内の電圧をいう。 The inverter controller includes a current control block that controls the DC / AC inverter so that an AC current synchronized with the phase of the commercial system voltage is output from the DC / AC inverter when the system is connected, and is independent when disconnected. A voltage control block is provided to control the DC / AC inverter so that a voltage of a predetermined level legally output to the system is output. The legally prescribed voltage levels are stipulated in Article 26 of the Electricity Business Act and Article 44 of the Enforcement Regulations of the Act, and are intended for low voltage consumers, 101 ± 6V for standard voltage 100V, Voltage within 202 ± 20V.
商用系統から解列して自立系統に給電する自立運転を行なう場合には、商用系統への逆充電防止及び非同期投入防止のために、系統連系用リレーの接点が溶着することなく正常であるか否かを検出する必要があり、また系統連系用リレーの接点が溶着している場合には、系統連系運転から自立運転への移行を阻止する必要がある。 When performing a self-sustaining operation in which power is disconnected from the commercial system and supplied to the independent system, the contact points of the grid interconnection relay are normal without welding to prevent reverse charging and asynchronous charging to the commercial system. It is necessary to detect whether or not, and when the contact of the grid interconnection relay is welded, it is necessary to prevent the transition from the grid interconnection operation to the independent operation.
特許文献１には、インバータ回路からの交流電力を平滑するフィルタ回路と、インバータ回路の運転状態を制御するインバータ回路制御手段と、系統連系用リレーの連系又は解列の状態の制御手段と、フィルタ回路と系統連系用リレーの間に接続され、フィルタ回路に流れる電流を検出する電流検出手段と、インバータ回路制御手段によりインバータ回路が停止状態に制御されているときに、系統連系用リレーの制御状態及び電流検出手段の検出結果に基づいて系統連系装置の異常を検出する手段とを有する系統連系装置が開示されている。 Patent Document 1 includes a filter circuit that smoothes AC power from an inverter circuit, inverter circuit control means that controls the operation state of the inverter circuit, control means that controls connection or disconnection of a grid interconnection relay, , Connected between the filter circuit and the grid connection relay, for detecting the current flowing through the filter circuit, and for the grid connection when the inverter circuit is controlled to be stopped by the inverter circuit control means. There is disclosed a grid interconnection device having means for detecting abnormality of the grid interconnection device based on the control state of the relay and the detection result of the current detection unit.
当該異常検出手段は、インバータ回路を停止した状態で、商用系統からフィルタ回路のコンデンサに無効電流が流れているか否かに基づいて、系統連系用リレーの接点が溶着しているか否かを判定するように構成されている。 The abnormality detection means determines whether or not the contact of the grid connection relay is welded based on whether or not reactive current is flowing from the commercial system to the capacitor of the filter circuit with the inverter circuit stopped. Is configured to do.
特許文献２には、商用系統が正常に運転されている場合に、ＤＣ／ＡＣインバータ回路を停止状態に制御し、系統連系用リレーを開放状態に制御している時、系統連系用リレーを構成する第一の系統連系用リレー、第二の系統連系用リレーについて、第一の系統連系用リレーの入力側と第二の系統連系用リレーの出力側の電位差と、第一の系統連系用リレーの出力側と第二の系統連系用リレーの入力側の電位差をそれぞれフォトカプラ等によって検出することで、インバータ回路と商用系統が連系する前に、第一の系統連系用リレーまたは第二の系統連系用リレーが溶着しているか否かを検出し、商用系統が停電した場合に、インバータ回路を作動させて、同様の検出動作を行なう系統連系装置が提案されている。 In Patent Document 2, when the commercial system is operating normally, the DC / AC inverter circuit is controlled to be in a stopped state, and the grid connection relay is controlled to be in an open state. About the first grid connection relay and the second grid connection relay, the potential difference between the input side of the first grid connection relay and the output side of the second grid connection relay, By detecting the potential difference between the output side of one grid connection relay and the input side of the second grid connection relay with a photocoupler, etc., before the inverter circuit and the commercial system are linked, A grid interconnection device that detects whether the grid interconnection relay or the second grid interconnection relay is welded and activates an inverter circuit to perform a similar detection operation when a commercial power failure occurs Has been proposed.
しかし、特許文献１に開示された系統連系装置の異常検出手段では、系統連系時または解列時にインバータを停止して商用系統からフィルタ回路に流れる無効電流の有無を検知する構成であるため、商用系統が停電して自立運転を起動するような場合には、系統連系用リレーの異常を検知することができないという問題があった。 However, the abnormality detection means of the grid interconnection device disclosed in Patent Document 1 is configured to detect the presence or absence of reactive current flowing from the commercial system to the filter circuit by stopping the inverter during grid interconnection or disconnection. In the case where the commercial system has a power failure and starts the self-sustained operation, there is a problem that an abnormality of the grid interconnection relay cannot be detected.
また、特許文献２に開示された系統連系装置では、第一の系統連系用リレーの入力側と第二の系統連系用リレーの出力側の電位差と、第一の系統連系用リレーの出力側と第二の系統連系用リレーの入力側の電位差をそれぞれ検出するための別途の回路素子が必要になり部品コストが嵩むという問題があった。 In the grid interconnection device disclosed in Patent Document 2, the potential difference between the input side of the first grid interconnection relay and the output side of the second grid interconnection relay, and the first grid interconnection relay There is a problem in that separate circuit elements for detecting the potential difference between the output side and the input side of the second grid interconnection relay are required, increasing the component cost.
さらには、商用系統の電圧が運用規定の適正範囲内であるか否かのみに基づいて停電検知していたため、ノイズの影響により誤検知する可能性、商用系統の停電時にＤＣ／ＡＣインバータ回路を作動させて系統連系用リレーの異常を検知する場合に、商用系統への負荷の接続状態によっては電圧変動のみでは誤検知するおそれもあった。 Furthermore, because the power failure was detected based only on whether or not the voltage of the commercial system was within the proper range of operation regulations, there was a possibility of erroneous detection due to the effects of noise, and the DC / AC inverter circuit could be When detecting the abnormality of the grid interconnection relay by operating, there is a possibility of erroneous detection only by voltage fluctuation depending on the connection state of the load to the commercial system.
本発明の目的は、上述した問題点に鑑み、商用系統が停電して自立運転を起動する場合に、部品コストが嵩むことなく、精度良く系統連系用リレーの異常を検知可能な系統連系用リレーの異常検出装置、及びパワーコンディショナを提供する点にある。 In view of the above-described problems, the object of the present invention is to provide a grid interconnection that can accurately detect an abnormality in the grid interconnection relay without increasing the component cost when the commercial grid is powered down and starts independent operation. An abnormality detection device for a power relay and a power conditioner are provided.
上述の目的を達成するため、本発明による系統連系用リレーの異常検出装置の第一の特徴構成は、特許請求の範囲の書類の請求項１に記載した通り、系統連系用リレーを介して商用系統と連系する系統連系運転と、自立系統用リレーを介して自立系統に給電する自立運転との何れかに切替可能なパワーコンディショナに組み込まれ、自立運転への切替時に系統連系用リレーの異常を検出する系統連系用リレー異常検出装置であって、商用系統電圧の有無を判定する商用系統電圧判定処理と、前記商用系統電圧判定処理の結果に基づいて、異常検出時の前記パワーコンディショナの出力電圧及び前記系統連系用リレーの異常判定のための基準電圧を異なる値に設定する電圧設定処理と、前記系統連系用リレーの接点が開成制御された状態で、前記パワーコンディショナの出力電圧と商用系統電圧との差分と、前記基準電圧に所定の信頼係数を掛けた値との大小関係に基づいて前記系統連系用リレーの異常判定を行なう異常検出処理と、を実行する異常検出処理部を備えている点にある。 In order to achieve the above-mentioned object, the first characteristic configuration of the abnormality detection device for the grid interconnection relay according to the present invention is as described in claim 1 of the claims, via the grid interconnection relay. Incorporated into a power conditioner that can be switched between grid-connected operation linked to the commercial system and autonomous operation that supplies power to the autonomous system via a relay for autonomous system. A system interconnection relay abnormality detection device for detecting an abnormality of a system relay, wherein an abnormality is detected based on a result of a commercial system voltage determination process for determining the presence or absence of a commercial system voltage and the commercial system voltage determination process In the state where the output voltage of the power conditioner and the reference voltage for determining the abnormality of the grid interconnection relay are set to different values, and the contact of the grid interconnection relay is controlled to be opened, Previous An abnormality detection process for determining an abnormality of the grid interconnection relay based on a difference between a difference between an output voltage of the inverter and a commercial grid voltage and a value obtained by multiplying the reference voltage by a predetermined reliability coefficient; It is in the point provided with the abnormality detection processing part which performs.
商用系統電圧が停電しているときに自立運転に移行するのであるが、一時的に商用系統電圧が低下して程なく復帰する場合もある。そのような場合に商用系統連系用リレーが溶着していると、非同期投入状態に到る等の不都合な事態が生じ、パワーコンディショナが破損するおそれも発生する。そこで、電圧設定処理の前に商用系統電圧判定処理を実行して、その結果に応じてパワーコンディショナの出力電圧及び系統連系用リレーの異常判定のための基準電圧を異なる値に設定することで、非同期投入や逆充電が回避できるようになる。例えば、商用系統電圧が検知される場合には、パワーコンディショナの出力電圧を０Ｖに、商用系統電圧の値を基準電圧に設定すれば、パワーコンディショナの破損を招くことなく、精度の高い接点の溶着判定が行なえるようになる。 When the commercial system voltage is interrupted, the operation shifts to the self-sustained operation. However, the commercial system voltage may temporarily decrease and may be restored soon. In such a case, if the commercial grid connection relay is welded, an inconvenient situation such as an asynchronous input state occurs, and the power conditioner may be damaged. Therefore, commercial voltage determination processing is executed before voltage setting processing, and the output voltage of the power conditioner and the reference voltage for determining abnormality of the grid interconnection relay are set to different values according to the result. As a result, asynchronous charging and reverse charging can be avoided. For example, when a commercial system voltage is detected, a highly accurate contact can be obtained without causing damage to the power conditioner by setting the output voltage of the power conditioner to 0 V and the value of the commercial system voltage to a reference voltage. It becomes possible to perform the welding judgment.
系統連系用リレーの接点が開成制御された状態で、電圧設定処理で設定された出力電圧がパワーコンディショナから出力されると異常検出処理が実行され、パワーコンディショナの出力電圧と商用系統電圧が検出されて、それらの差分と電圧設定処理で設定された基準電圧に所定の信頼係数を掛けた値との大小関係が判定される。例えば、接点が溶着していなければ、停電時には商用系統電圧が０Ｖ、パワーコンディショナの出力電圧が４０Ｖと検知され、信頼係数Ｒ＝０．５（Ｒは、Ｒ＜１の正数）であったとすれば、それらの電圧の差分４０Ｖと比較値２０Ｖ（＝４０×０．５）との大小関係が判定され、接点が溶着していれば、停電時には商用系統電圧が４０Ｖ、パワーコンディショナの出力電圧が４０Ｖと検知され、それらの電圧の差分０Ｖと比較値２０Ｖ（＝４０×０．５）との大小関係が判定され、その結果に基づいて接点が溶着しているか否かが判定される。 If the output voltage set in the voltage setting process is output from the power conditioner while the contact of the grid connection relay is controlled to open, the abnormality detection process is executed, and the output voltage of the power conditioner and the commercial system voltage Are detected, and the magnitude relation between the difference between them and a value obtained by multiplying the reference voltage set in the voltage setting process by a predetermined reliability coefficient is determined. For example, if the contacts are not welded, the commercial system voltage is detected as 0V and the output voltage of the power conditioner is detected as 40V at the time of a power failure, and the reliability coefficient R = 0.5 (R is a positive number of R <1). For example, the magnitude relationship between the voltage difference 40V and the comparison value 20V (= 40 × 0.5) is determined. If the contacts are welded, the commercial system voltage is 40V and the power conditioner The output voltage is detected as 40 V, the magnitude relationship between the difference 0 V between these voltages and the comparison value 20 V (= 40 × 0.5) is determined, and it is determined whether or not the contacts are welded based on the result. The
そして、パワーコンディショナの出力電圧や出力電流、商用系統電圧を検知するための回路素子は本来パワーコンディショナの制御に必要な回路素子であるので、系統連系用リレーの溶着を判定するために別途のセンサや回路素子を準備する必要もない。 And since the circuit elements for detecting the output voltage, output current, and commercial system voltage of the power conditioner are originally circuit elements necessary for the control of the power conditioner, in order to determine the welding of the grid connection relay There is no need to prepare a separate sensor or circuit element.
同第二の特徴構成は、同請求項２に記載した通り、上述の第一の特徴構成に加えて、前記異常検出処理部は、前記系統連系用リレーの全接点を開成制御した後に前記異常検出処理を実行するとともに、一接点毎に単独で閉成制御する度に前記異常検出処理を実行するように構成されている点にある。 As described in claim 2, the second characteristic configuration is the above-described first characteristic configuration, wherein the abnormality detection processing unit performs opening control of all the contacts of the grid interconnection relay. The abnormality detection process is executed, and the abnormality detection process is executed each time the closing control is performed independently for each contact.
パワーコンディショナの出力が単相であるか３相であるかによって系統連系用リレーの接点数が変動し、また何れの接点が溶着しているかによって上述の異常検出処理の結果が異なる。そこで、系統連系用リレーの全接点を開成制御した後に異常検出処理を実行し、溶着していると判定されると全接点が溶着していることが明らかになり、一接点毎に単独で閉成制御する度に異常検出処理を実行し、溶着していると判定されると開成制御されている接点が溶着していることが明らかになる。 The number of contacts of the grid interconnection relay varies depending on whether the output of the power conditioner is single phase or three phases, and the result of the abnormality detection process described above varies depending on which contact is welded. Therefore, after performing the opening control of all the contacts of the grid connection relay, the abnormality detection process is executed, and if it is determined that the contacts are welded, it becomes clear that all the contacts are welded, An abnormality detection process is executed every time the closing control is performed, and if it is determined that the welding is performed, it becomes clear that the contact that is subjected to the opening control is welded.
同第三の特徴構成は、同請求項３に記載した通り、上述の第一または第二の特徴構成に加えて、前記商用系統電圧判定処理は、異常検出処理時のパワーコンディショナの出力電圧設定値に所定の信頼係数を掛けた値と、商用系統電圧との大小関係、及び、自立系統周波数に所定の信頼係数を掛けた値と、商用系統周波数との大小関係に基づいて、商用系統電圧の有無を判定するように構成されている点にある。 In the third feature configuration, as described in claim 3, in addition to the first or second feature configuration described above, the commercial system voltage determination processing is performed by the output voltage of the power conditioner during the abnormality detection processing. Based on the magnitude relationship between the value obtained by multiplying the set value by the predetermined reliability coefficient and the commercial system voltage, and the magnitude relationship between the value obtained by multiplying the independent system frequency by the predetermined reliability coefficient and the commercial system frequency. It is in the point which is comprised so that the presence or absence of a voltage may be determined.
商用系統電圧のみならず商用系統周波数をもチェックすることにより、ノイズ等による誤判定を招くことなく精度よく商用系統電圧の有無を判定できるようになる。 By checking not only the commercial system voltage but also the commercial system frequency, it is possible to accurately determine the presence or absence of the commercial system voltage without causing erroneous determination due to noise or the like.
同第四の特徴構成は、同請求項４に記載した通り、上述の第一から第三の何れかの特徴構成に加えて、前記異常検出処理部は、前記商用系統電圧判定処理により前記商用系統電圧が無いと判定され、前記パワーコンディショナから電圧を出力する場合に、前記異常検出処理に加えて前記パワーコンディショナからの出力電流の有無に基づいて前記系統連系用リレーの異常判定を行なうように構成されている点にある。 In the fourth feature configuration, as described in claim 4, in addition to any one of the first to third feature configurations described above, the abnormality detection processing unit is configured to perform the commercial system voltage determination process. When it is determined that there is no grid voltage and a voltage is output from the power conditioner, an abnormality determination of the grid interconnection relay is performed based on the presence or absence of an output current from the power conditioner in addition to the abnormality detection process. In that it is configured to do.
系統連系用リレーの接点が開成制御された状態で、電圧設定処理で設定された出力電圧がパワーコンディショナから出力されると、パワーコンディショナの出力電流がチェックされる。このとき商用系統に負荷が接続され且つ接点が導通していると負荷に電流が流れるので、この電流の有無に基づいて接点が溶着されているか否かが判定される。 When the output voltage set by the voltage setting process is output from the power conditioner while the contact of the grid interconnection relay is controlled to open, the output current of the power conditioner is checked. At this time, if a load is connected to the commercial system and the contact is conductive, a current flows through the load. Therefore, whether or not the contact is welded is determined based on the presence or absence of this current.
本発明によるパワーコンディショナの特徴構成は、同請求項５に記載した通り、系統連系用リレーを介して商用系統と連系する系統連系運転と、自立系統用リレーを介して自立系統に給電する自立運転とを切替可能な制御装置を備えている単相または三相のパワーコンディショナであって、上述した第一から第四の何れかの特徴構成を備えた系統連系用リレーの異常検出装置が前記制御装置に組み込まれている点にある。 The characteristic configuration of the power conditioner according to the present invention is that, as described in claim 5, the grid connection operation linked to the commercial system via the grid interconnection relay and the independent system via the independent grid relay A single-phase or three-phase power conditioner having a control device capable of switching between self-sustained operation to supply power, the grid interconnection relay having any one of the first to fourth characteristic configurations described above An abnormality detection device is incorporated in the control device.
異常検出処理部により系統連系用リレーの接点が溶着していると判定されるような場合に、自立運転を回避して商用系統への逆充電及び非同期投入という不都合な事態の発生を未然に防止できるようになる。 When the abnormality detection processing unit determines that the contact point of the grid connection relay is welded, it is possible to avoid the inconvenient situation of reverse charging and asynchronous charging to the commercial system by avoiding independent operation. Can be prevented.
以上説明した通り、本発明によれば、商用系統が停電して自立運転を起動する場合に、部品コストが嵩むことなく、精度良く系統連系用リレーの異常を検知可能な系統連系用リレーの異常検出装置、及びパワーコンディショナを提供することができるようになる。 As described above, according to the present invention, when a commercial system starts a power failure and starts a self-sustained operation, the system connection relay can accurately detect the abnormality of the system connection relay without increasing the component cost. It is possible to provide an abnormality detection device and a power conditioner.
以下、本発明による系統連系用リレーの異常検出装置及びパワーコンディショナを図面に基づいて説明する。 Hereinafter, an abnormality detection apparatus and a power conditioner for a grid interconnection relay according to the present invention will be described with reference to the drawings.
図１には、分散型電源の一例である太陽光発電装置１が示されている。太陽光発電装置１は、太陽電池パネルＳＰと、太陽電池パネルＳＰが接続されたパワーコンディショナＰＣＳを備えて構成されている。太陽電池パネルＳＰで発電された直流電力は直流遮断器及びサージアブソーバ（図示せず）を介してパワーコンディショナＰＣＳに供給される。 FIG. 1 shows a solar power generation device 1 that is an example of a distributed power source. The solar power generation device 1 includes a solar battery panel SP and a power conditioner PCS to which the solar battery panel SP is connected. The DC power generated by the solar cell panel SP is supplied to the power conditioner PCS via a DC circuit breaker and a surge absorber (not shown).
パワーコンディショナＰＣＳは、太陽電池パネルＳＰで発電された直流電圧を所定の直流リンク電圧Ｖｄｃに昇圧するＤＣ／ＤＣコンバータ２と、昇圧された直流リンク電圧Ｖｄｃを所定の交流電圧に変換するＤＣ／ＡＣインバータ３と、ＤＣ／ＡＣインバータ３から出力される交流電圧から高調波を除去するＬＣフィルタ４と、ＤＣ／ＤＣコンバータ２及びＤＣ／ＡＣインバータ３を制御する制御装置５等を備えている。 The power conditioner PCS converts the DC voltage generated by the solar battery panel SP to a predetermined DC link voltage Vdc and converts the boosted DC link voltage Vdc into a predetermined AC voltage. A DC / AC inverter 3, an LC filter 4 for removing harmonics from the AC voltage output from the DC / AC inverter 3, a control device 5 for controlling the DC / DC converter 2 and the DC / AC inverter 3, and the like. Yes.
パワーコンディショナＰＣＳで変換された交流電力は、系統連系用リレーＲｙ１を介して商用系統１００と連系して交流負荷Ｒｕｗに給電可能に構成され、停電等によって商用系統１００から解列すると、自立系統用リレーＲｙ２を介して自立負荷Ｒｓｄに給電可能に接続されている。系統連系用リレーＲｙ１の接点がＳｕ，Ｓｗ、自立系統用リレーＲｙ２の２つの接点がＳｓｄで示されている。 The AC power converted by the power conditioner PCS is configured to be connected to the commercial system 100 via the grid connection relay Ry1 and to be able to supply power to the AC load R uw. The power supply is connected to the self-supporting load R sd via the self-supporting system relay Ry2. The contacts of the grid interconnection relay Ry1 are indicated by S u and S w , and the two contacts of the independent grid relay Ry2 are indicated by S sd .
パワーコンディショナＰＣＳの制御装置５は、マイクロコンピュータと、メモリ素子及びＡＤ変換部を含む入出力素子等を備えた周辺回路で構成され、ＤＣ／ＤＣコンバータ２の昇圧スイッチを制御するコンバータ制御部５ａと、ＤＣ／ＡＣインバータ３のブリッジを構成するスイッチを制御するインバータ制御部５ｂと、系統連系用リレーＲｙ１の異常を検知する異常検出処理部５ｃを備えている。インバータ制御部５ｂは、系統連系用リレーＲｙ１または自立系統用リレーＲｙ２を制御してインバータ４を系統連系運転または自立運転するように構成されている。 The control device 5 of the power conditioner PCS includes a microcomputer and a peripheral circuit including an input / output element including a memory element and an AD conversion unit, and a converter control unit 5a that controls a boost switch of the DC / DC converter 2. And an inverter control unit 5b that controls a switch that constitutes a bridge of the DC / AC inverter 3, and an abnormality detection processing unit 5c that detects an abnormality of the grid interconnection relay Ry1. The inverter control unit 5b is configured to control the grid interconnection relay Ry1 or the independent grid relay Ry2 to cause the inverter 4 to perform grid grid operation or autonomous operation.
コンバータ制御部５ａはＤＣ／ＤＣコンバータ２への入力電圧、入力電流、出力電圧をモニタして、太陽電池パネルＳＰを最大電力点で動作させるＭＰＰＴ制御等を実行しつつ、所定の出力電圧に昇圧制御するように構成されている。 The converter control unit 5a monitors the input voltage, input current, and output voltage to the DC / DC converter 2 and performs MPPT control to operate the solar panel SP at the maximum power point, and boosts it to a predetermined output voltage. Configured to control.
インバータ制御部５ｂは、系統連系運転時に商用系統電圧の位相に同期するようにインバータ３の出力電流を制御する電流制御ブロックと、解列時に自立系統に所定電圧の交流電力を給電する電圧制御ブロックと、系統連系運転時に単独運転状態か否かを検出する単独運転検出ブロック等の機能ブロックを備えている。 The inverter control unit 5b includes a current control block that controls the output current of the inverter 3 so as to synchronize with the phase of the commercial system voltage during grid connection operation, and a voltage control that supplies AC power of a predetermined voltage to the independent system when disconnected. A block and functional blocks such as an isolated operation detection block for detecting whether or not the system is in an isolated operation state during grid interconnection operation are provided.
異常検出処理部５ｃは、自立運転への移行時に系統連系用リレーＲｙ１の異常の有無を検知し、系統連系用リレーＲｙ１に接点溶着異常が発生していることが検知されると、故障を表す警報表示を点灯するとともに、インバータ制御部５ｂによる自立運転制御を停止するように構成され、本発明の異常検出装置として機能する。 The abnormality detection processing unit 5c detects whether or not the grid connection relay Ry1 is abnormal when shifting to the self-sustaining operation, and if it is detected that a contact welding abnormality has occurred in the grid connection relay Ry1, Is turned on and the independent operation control by the inverter control unit 5b is stopped, and functions as the abnormality detection device of the present invention.
ＬＣフィルタ４を構成するインダクタＬの下流側にパワーコンディショナＰＣＳの出力電流ｉｕｗを検知する電流トランスＣＴが設けられ、インタフェース回路６を介して電流信号が制御装置５に入力されている。さらに、自立系統用リレーＲｙ２の上流側にパワーコンディショナＰＣＳの出力電圧ｅｓｄを検知する電圧検知用の分圧回路、系統連系用リレーＲｙ１の下流側に商用系統電圧ｅｕｗを検知する分圧回路がそれぞれ設けられている。各分圧回路の出力は制御装置５のＡＤ変換部に入力され、その値から商用系統周波数ｆＧｒｉｄ及び自立系統周波数ｆｓｄが得られるように構成されている。 A current transformer CT that detects the output current i uw of the power conditioner PCS is provided downstream of the inductor L that constitutes the LC filter 4, and a current signal is input to the control device 5 via the interface circuit 6. Further, the voltage dividing circuit for voltage detection that detects the output voltage e sd of the power conditioner PCS upstream autonomous systems relay Ry2, detects a commercial system voltage e uw downstream system interconnection relay Ry1 min Each pressure circuit is provided. The output of each voltage dividing circuit is input to the AD conversion unit of the control device 5, and the commercial system frequency f Grid and the independent system frequency f sd are obtained from the values.
インバータ制御部５ｂは、太陽電池パネルＳＰの発電電力が商用系統との連系が可能な値になると、系統連系用リレーＲｙ１を閉成して系統連系運転し、太陽電池パネルＳＰの発電電力が低下したり単独運転検出ブロックにより単独運転状態であると検出されたりすると、系統連系用リレーＲｙ１を開成して解列する。 When the generated power of the solar panel SP becomes a value that enables interconnection with the commercial system, the inverter control unit 5b closes the grid interconnection relay Ry1 and performs grid interconnection operation, and generates power from the solar panel SP. When the power is reduced or the isolated operation detection block detects that the power is in the isolated operation state, the grid interconnection relay Ry1 is opened and disconnected.
インバータ制御部５ｂは、単独運転状態が原因で解列した場合で、太陽電池パネルＳＰの発電電力が自立運転に十分な値である場合は、異常検出処理部５ｃを起動して系統連系用リレーＲｙ１の異常検知を行ない、異常検出処理部５ｃにより系統連系用リレーＲｙ１が正常であると判定されると自立系統用リレーＲｙ２を閉成して自立運転し、異常検出処理部５ｃにより系統連系用リレーＲｙ１が異常であると判定されると自立系統用リレーＲｙ２を閉成することなくＤＣ／ＡＣインバータ３を停止するように構成されている。 When the inverter control unit 5b is disconnected due to a single operation state, and the generated power of the solar panel SP is a value sufficient for independent operation, the abnormality detection processing unit 5c is activated to connect to the grid. When the abnormality detection processing unit 5c determines that the grid interconnection relay Ry1 is normal, the relay Ry1 is closed and the autonomous operation is performed by the abnormality detection processing unit 5c. When it is determined that the interconnection relay Ry1 is abnormal, the DC / AC inverter 3 is stopped without closing the independent system relay Ry2.
以下、異常検出処理部５ｃにより実行される系統連系用リレーの異常検出方法について説明する。異常検出処理部５ｃで実行される異常検出処理には、系統連系用リレーＲｙ１の接点を開成または閉成制御する接点制御処理と、商用系統電圧判定処理と、電圧設定処理と、第１判定処理と、第二判定処理が含まれる。 Hereinafter, an abnormality detection method for the grid interconnection relay executed by the abnormality detection processing unit 5c will be described. The abnormality detection processing executed by the abnormality detection processing unit 5c includes contact control processing for opening or closing the contact of the grid interconnection relay Ry1, commercial system voltage determination processing, voltage setting processing, and first determination. A process and a second determination process are included.
異常検出処理部５ｃは、系統連系用リレーＲｙ１の全接点Ｓｕ，Ｓｗを開成制御した後に接点が溶着しているか否かを判定する後述の第１判定処理及び第２判定処理を実行するとともに、各接点ＳｕまたはＳｗ毎に閉成制御する度に第１判定処理及び第２判定処理を実行するように構成されている。 Abnormality detection processing unit 5c, executes a first determination process and the second determination process described below determines whether the contact is welded after opening controls all contacts S u, S w of the grid interconnection relay Ry1 while it is configured to execute a first determination process and the second determination process each time the closing control for each contact S u or S w.
系統連系用リレーＲｙ１の全接点Ｓｕ，Ｓｗを開成制御した後に第１判定処理及び第２判定処理を実行し、その結果、溶着していると判定できると全接点Ｓｕ，Ｓｗが溶着していることが明らかになる。この時点で正常と判定できる場合には、一接点ＳｕまたはＳｗ毎に単独で閉成制御する度に第１判定処理及び第２判定処理を実行する。それぞれで溶着していると判定できると、その時に開成制御されている接点が溶着していることが明らかになる。 When the first determination process and the second determination process are performed after opening control of all the contacts S u and S w of the grid interconnection relay Ry1, and as a result, it can be determined that all the contacts S u and S w are welded, It becomes clear that is welded. When it can be judged to be normal at this point, to perform a first determination process and the second determination process each time the closing control alone every one contact S u or S w. If it can be determined that they are welded to each other, it becomes clear that the contact whose opening is controlled at that time is welded.
図２には、この系統連系用リレーＲｙ１に対する制御シーケンスが示されている。異常検出処理部５ｃが起動すると、全接点Ｓｕ，Ｓｗを開成制御した状態で、接点Ｓｕ，Ｓｗに対するチェックである第１及び第２判定処理を行ない、次に接点Ｓｕを閉成制御して接点Ｓｗに対するチェックである第１及び第２判定処理を行ない、さらに接点Ｓｕを開成制御し所定の遅延時間Ｔｄｌｙの後に接点Ｓｗを閉成制御して接点Ｓｕに対するチェックである第１及び第２判定処理を行なう。 FIG. 2 shows a control sequence for the grid interconnection relay Ry1. When the abnormality detection processing unit 5c is activated, all the contacts S u, while opening control S w, the contact S u, performs first and second determination process is a check for S w, then contact S u closed for contacts S u and closing control contact S w after Configuration control and performs first and second determination process is a check for contact S w, the further contact S u the opening control to a predetermined delay time T dly First and second determination processing, which is a check, is performed.
本実施形態では、各チェック時間及び遅延時間Ｔｄｌｙがそれぞれ２００ｍｓｅｃ．に設定されている。このような系統連系用リレーＲｙ１に対する開閉制御シーケンスが上述した接点制御処理ステップとなる。 In this embodiment, each check time and delay time T dly are 200 msec. Is set to Such an open / close control sequence for the grid interconnection relay Ry1 is the contact control processing step described above.
図３には、上述した商用系統電圧判定処理ステップ及び電圧設定処理ステップを実行する系統連系用リレーの溶着判定準備フローが示されている。商用系統電圧判定処理ステップでは、自立運転する必要がある場合に（Ｓ１）、系統連系用リレーＲｙ１の全ての接点が開成制御され（Ｓ２）、商用系統電圧ｅｕｗがチェックされ（Ｓ３）、以下に示す〔数１〕に基づいて商用系統電圧の有無がチェックされる（Ｓ４）。
尚、Ｅ＊ ｓｄ．ｒｍｓは自立運転時の出力電圧実効値の指令値、ｘは判定の精度を確保するために０＜ｘ＜１の範囲の値に設定される信頼係数で、本実施形態ではｘ＝０．５に設定されている。また、自立系統周波数ｆｓｄは、商用系統周波数ｆＧｒｉｄと同じ値に設定されている。 Note that E * sd. rms is a command value of the effective value of the output voltage during the self-sustaining operation, and x is a reliability coefficient set to a value in the range of 0 <x <1 in order to ensure the accuracy of determination. Is set to Further, the independent system frequency f sd is set to the same value as the commercial system frequency f Grid .
商用系統電圧が少なくとも１周期（商用系統周波数が５０Ｈｚであれば、２０ｍｓｅｃ．）計測されて最大瞬時値の絶対値｜ｅｕｗ｜が求められ、絶対値｜ｅｕｗ｜と、自立運転時の出力電圧実効値の指令値Ｅ＊ ｓｄ．ｒｍｓと信頼係数ｘとの積とが比較される。複数周期計測して各周期の最大値の平均を求めてもよい。 The commercial system voltage is measured for at least one cycle (20 msec. If the commercial system frequency is 50 Hz), the absolute value | e uw | of the maximum instantaneous value is obtained, and the absolute value | e uw | Voltage effective value command value E * sd. The product of rms and confidence factor x is compared. A plurality of periods may be measured and the average of the maximum values of each period may be obtained.
さらに、商用系統周波数と、自立系統周波数と信頼係数ｘとの積とが比較される。信頼係数ｘの値は判断の信頼度を担保するための係数で、その値が１に近いほどノイズの影響を受け易くなるが厳しく判定でき、０に近いほどノイズの影響を受け難くなるが緩やかな判定となる。通常は中間の値０．５が好ましく用いられる。 Further, the commercial system frequency is compared with the product of the independent system frequency and the reliability coefficient x. The value of the reliability coefficient x is a coefficient for ensuring the reliability of judgment. The closer the value is to 1, the more easily affected by noise, but the more severe it can be judged. It becomes a bad judgment. Usually, an intermediate value of 0.5 is preferably used.
例えば、商用系統電圧｜ｅｕｗ｜が０Ｖで、パワーコンディショナの出力電圧の指令値Ｅ＊ ｓｄ．ｒｍｓが４０Ｖ、ｘ＝０．５の場合、〔数１〕は以下のようになる。
｜ｅｕｗ｜＝０ ＜ ０．５×４０＝２０
ｆＧｒｉｄ ＝０ ＜ ０．５×５０＝２５
For example, when the commercial system voltage | e uw | is 0 V, the command value E * sd. When rms is 40 V and x = 0.5, [Equation 1] is as follows.
| E uw | = 0 <0.5 × 40 = 20
f Grid = 0 <0.5 × 50 = 25
例えば、商用系統電圧｜ｅｕｗ｜が１４１Ｖで、パワーコンディショナの出力電圧の指令値Ｅ＊ ｓｄ．ｒｍｓが４０Ｖ、ｘ＝０．５の場合、〔数１〕は以下のようになる。
｜ｅｕｗ｜＝１４１ ＞ ０．５×４０＝２０
ｆＧｒｉｄ ＝５０ ＞ ０．５×５０＝２５
For example, when the commercial system voltage | e uw | is 141 V, the output voltage command value E * sd. When rms is 40 V and x = 0.5, [Equation 1] is as follows.
| E uw | = 141> 0.5 × 40 = 20
f Grid = 50> 0.5 × 50 = 25
つまり、ステップＳ４では、〔数１〕の２式が共に成立するときに商用系統電圧が有ると判断し、何れも成立しないときに商用系統電圧が無いと判断される。上述のステップＳ３，Ｓ４が、電圧設定処理ステップで設定されたパワーコンディショナの出力電圧設定値に所定の信頼係数を掛けた値と、商用系統電圧との大小関係、及び、自立系統周波数に所定の信頼係数を掛けた値と、商用系統周波数との大小関係に基づいて、商用系統電圧の有無を判定する商用系統電圧判定処理ステップとなる。 That is, in step S4, it is determined that there is a commercial system voltage when both of the two formulas [Equation 1] are established, and it is determined that there is no commercial system voltage when neither is established. Steps S3 and S4 described above are predetermined for the magnitude relationship between the value obtained by multiplying the output voltage setting value of the power conditioner set in the voltage setting processing step by a predetermined reliability coefficient and the commercial grid voltage, and for the independent grid frequency. This is a commercial system voltage determination processing step for determining the presence or absence of the commercial system voltage based on the magnitude relationship between the value multiplied by the reliability coefficient and the commercial system frequency.
商用系統電圧のみならず商用系統周波数をもチェックすることにより、ノイズ等による誤判定を招くことなく精度よく商用系統電圧の有無の判定が可能になる。 By checking not only the commercial system voltage but also the commercial system frequency, it is possible to accurately determine the presence or absence of the commercial system voltage without causing erroneous determination due to noise or the like.
商用系統電圧判定処理ステップにより商用系統電圧が有ると判断されると、接点の溶着判断を行なう基準値Ｅｃｈｋが商用系統電圧の実効値Ｅｕｗ．ｒｍｓに設定され、パワーコンディショナの出力電圧と商用系統電圧との差分の判断を行う遅延時間Ｔｃｈｋが商用系統周波数の逆数に設定される（Ｓ５）。また、商用系統電圧が無いと判断されると、異常検出時のパワーコンディショナ３の出力電圧の指令値が設定されるとともに（Ｓ６）、接点の溶着判断を行なう基準値Ｅｃｈｋが自立運転時の出力電圧の実効値Ｅｓｄ.ｒｍｓに設定され、この時の遅延時間Ｔｃｈｋが自立系統周波数の逆数に設定される（Ｓ７）。つまり、商用系統電圧が有ると判断されるとパワーコンディショナ３は停止されて出力電圧は０Ｖとなる。上述のステップＳ５からステップＳ７が電圧設定処理ステップとなる。 If it is determined in the commercial system voltage determination processing step that there is a commercial system voltage, the reference value E chk for determining contact welding is determined as the effective value E uw. The delay time T chk for determining the difference between the inverter output voltage and the commercial grid voltage is set to the reciprocal of the commercial grid frequency (S5). If it is determined that there is no commercial system voltage, the command value of the output voltage of the power conditioner 3 at the time of detecting an abnormality is set (S6), and the reference value E chk for determining the welding of the contact is set in the independent operation. The effective value E sd.rms of the output voltage is set, and the delay time T chk at this time is set to the reciprocal of the independent system frequency (S7). That is, when it is determined that there is a commercial system voltage, the power conditioner 3 is stopped and the output voltage becomes 0V. Steps S5 to S7 described above are voltage setting processing steps.
上述した出力電圧の指令値ｅ＊ ｓｄは、以下の〔数２〕の通りである。
ここで、Ｅ＊ ｓｄ.ｒｍｓは出力電圧の実効値の指令値、θｓｄは出力電圧の位相角度である。Ｅ＊ ｓｄ.ｒｍｓ＝４０Ｖとの値は、系統連系用リレーに対する異常検出処理時の指令値であり、正常判定後の指令値は、Ｅ＊ ｓｄ.ｒｍｓ＝１００Ｖとなる。 Here, E * sd.rms is the command value of the effective value of the output voltage, and θ sd is the phase angle of the output voltage. The value of E * sd.rms = 40V is a command value at the time of abnormality detection processing for the grid interconnection relay, and the command value after normality determination is E * sd.rms = 100V.
つまり、電圧設定処理ステップの前に商用系統電圧の有無を判定する商用系統電圧判定処理ステップが実行され、商用系統電圧判定処理ステップの結果に基づいて、電圧設定処理ステップではパワーコンディショナの出力電圧及び系統連系用リレーの異常判定のための基準電圧が異なる値に設定される。 That is, before the voltage setting process step, the commercial system voltage determination process step for determining the presence or absence of the commercial system voltage is executed. Based on the result of the commercial system voltage determination process step, the output voltage of the power conditioner is determined in the voltage setting process step. In addition, the reference voltage for determining the abnormality of the grid interconnection relay is set to a different value.
商用系統電圧が停電すると自立運転に移行するのであるが、一時的に商用系統電圧が低下して程なく復帰する場合もある。そのような場合に系統連系用リレーが溶着していると、非同期投入状態に到る等の不都合な事態が生じ、パワーコンディショナが破損するおそれも発生する。 When the commercial system voltage is interrupted, the operation shifts to the self-sustained operation. However, the commercial system voltage may temporarily decrease and may be restored soon. In such a case, if the grid connection relay is welded, an inconvenient situation such as reaching an asynchronous input state occurs, and the power conditioner may be damaged.
そこで、電圧設定処理の前に商用系統電圧判定処理を実行して、その結果に応じてパワーコンディショナの出力電圧及び系統連系用リレーの異常判定のための基準電圧を異なる値に設定することで、系統連系用のリレーの異常判定を精度よく行なうことができ、非同期投入や逆充電が回避できるようになる。 Therefore, commercial voltage determination processing is executed before voltage setting processing, and the output voltage of the power conditioner and the reference voltage for determining abnormality of the grid interconnection relay are set to different values according to the result. Therefore, it is possible to accurately determine the abnormality of the grid interconnection relay and to avoid asynchronous charging and reverse charging.
例えば、商用系統電圧が検知される場合には、パワーコンディショナの出力電圧を０Ｖに、商用系統電圧の値を基準電圧に設定すれば、パワーコンディショナの破損を招くことなく、精度の高い接点の溶着判定が行なえるようになる。 For example, when a commercial system voltage is detected, a highly accurate contact can be obtained without causing damage to the power conditioner by setting the output voltage of the power conditioner to 0 V and the value of the commercial system voltage to a reference voltage. It becomes possible to perform the welding judgment.
図４には、系統連系用リレーの溶着判定フローが示されている。自立運転が起動されると（Ｓ１１）、上述の接点制御処理ステップが実行されて（Ｓ１２）、系統連系用リレーの接点が開成制御された状態で、パワーコンディショナの出力電流の有無に基づいて系統連系用リレーＲｙ１の異常判定を行なう第１判定処理と（Ｓ１３，Ｓ１７）、系統連系用リレーＲｙ１の接点が開成制御された状態で、パワーコンディショナの出力電圧と商用系統電圧との差分と、基準電圧に所定の信頼係数を掛けた値との大小関係に基づいて系統連系用リレーの異常判定を行なう第２判定処理と（Ｓ１４，Ｓ１５，Ｓ１６，Ｓ１７）が実行され、全接点について第１判定処理と第２判定処理が終了するまで、接点制御処理ステップＳ１２が繰り返される（Ｓ１８）。 FIG. 4 shows a welding determination flow of the grid interconnection relay. When the self-sustained operation is started (S11), the above-described contact control processing step is executed (S12), and based on the presence / absence of the output current of the power conditioner with the contact of the grid interconnection relay being controlled to open. The first determination process for determining abnormality of the grid interconnection relay Ry1 (S13, S17), and the output voltage of the power conditioner and the commercial grid voltage in the state where the contact of the grid interconnection relay Ry1 is controlled to open And a second determination process (S14, S15, S16, S17) for determining abnormality of the grid interconnection relay based on the magnitude relationship between the difference between the reference voltage and a value obtained by multiplying the reference voltage by a predetermined reliability coefficient, The contact control process step S12 is repeated until the first determination process and the second determination process are completed for all the contacts (S18).
系統連系用リレーＲｙ１の接点が開成制御された状態で、電圧設定処理で設定された出力電圧がパワーコンディショナから出力されると、第１判定処理が実行されてパワーコンディショナの出力電流がチェックされる。このとき商用系統に負荷Ｒｕｗ（図１参照）が接続され且つ接点Ｓｕ，Ｓｗが導通していると負荷Ｒｕｗに電流が流れるので、この電流の有無に基づいて接点が溶着されているか否かが判定される。尚、系統連系用リレーＲｙ１の接点が開成制御された状態とは、上述した接点制御処理ステップに対応して、全接点が開成制御された状態、及び、何れか一つの接点が閉成制御され、他の接点が開成制御された状態の何れかを意味する。 When the output voltage set in the voltage setting process is output from the power conditioner while the contact of the grid connection relay Ry1 is controlled to open, the first determination process is executed and the output current of the power conditioner is Checked. At this time, if the load R uw (see FIG. 1) is connected to the commercial system and the contacts S u and Sw are conducted, a current flows through the load R uw , so the contacts are welded based on the presence or absence of this current. It is determined whether or not there is. Note that the state in which the contacts of the grid interconnection relay Ry1 are controlled to open means that all the contacts are controlled to open corresponding to the above-described contact control processing step, and any one contact is controlled to close. It means that the other contact is controlled to be opened.
図５に示すように、具体的には、所定のサンプリング周期Ｔｓで計測したパワーコンディショナＰＣＳの出力電流ｉｕｗが少なくとも３回連続して閾値Ｉｕｗ.ｃｈｋ以上であり、且つ、計測する度にその値が大きくなるというという条件が成立する場合に（Ｓ１３，ＮＧ）、系統連系用リレーＲｙ１の接点が溶着していると判断して、メモリ素子に設定されたエラーフラグ記憶領域にフラグをセットする（Ｓ１７）。エラーフラグがセットされると、パワーコンディショナＰＣＳの表示パネルに異常表示が点灯されるように構成されている。本実施形態では、自立運転時の供給電力１．５Ｋｗを基準に、閾値Ｉｕｗ.ｃｈｋ＝１５Ａ、サンプリング周期Ｔｓ＝５０μｓｅｃ．（ＤＣ／ＡＣインバータのスイッチング周期に相当）に設定されている。 As shown in FIG. 5, specifically, the output current i uw of the power conditioner PCS measured at a predetermined sampling period T s is equal to or more than the threshold value I uw.chk continuously for at least three times. When the condition that the value increases every time is satisfied (S13, NG), it is determined that the contact of the grid interconnection relay Ry1 is welded, and the error flag storage area set in the memory element is stored. A flag is set (S17). When the error flag is set, an abnormality display is turned on on the display panel of the inverter PCS. In the present embodiment, the threshold I uw.chk = 15 A, the sampling period T s = 50 μsec. (Corresponding to the switching cycle of the DC / AC inverter).
ステップＳ１３で、パワーコンディショナＰＣＳの出力電流ｉｕｗが少なくとも３回連続して閾値Ｉｕｗ.ｃｈｋ以上であり、計測する度にその値が大きくなるというという条件が成立しない状態が所定時間（例えば数サイクル）継続すると、負荷Ｒｕｗが接続されていないために電流が検知できないと判定して、所定の遅延時間の後（Ｓ１４）、第２判定処理が実行される。 In step S13, a state in which the condition that the output current i uw of the power conditioner PCS is equal to or greater than the threshold value I uw.chk for at least three consecutive times and the value increases every measurement is not satisfied for a predetermined time (for example, When several cycles continue, it is determined that the current cannot be detected because the load R uw is not connected, and the second determination process is executed after a predetermined delay time (S14).
第２判定処理では、遅延時間の間にパワーコンディショナＰＣＳの出力電圧と商用系統電圧の実効値が計測されて、それらの差分の絶対値｜Ｅｓｄ．ｒｍｓ−Ｅｕｗ．ｒｍｓ｜と、電圧設定処理ステップで設定された基準電圧Ｅｃｈｋに所定の信頼係数ｘを掛けた値との大小関係が判定される（Ｓ１５）。 In the second determination process, the effective value of the output voltage of the power conditioner PCS and the commercial system voltage is measured during the delay time, and the absolute value | E sd. rms- E u. A magnitude relationship between rms | and a value obtained by multiplying the reference voltage E chk set in the voltage setting processing step by a predetermined reliability coefficient x is determined (S15).
例えば、接点が溶着していなければ、商用系統の停電時には商用系統電圧が０Ｖ、パワーコンディショナの出力電圧が４０Ｖと検知されるので、信頼係数Ｒ＝０．５（Ｒは、Ｒ＜１の正数）とすれば、差分の絶対値｜Ｅｓｄ．ｒｍｓ−Ｅｕｗ．ｒｍｓ｜＝４０Ｖに対して比較値２０Ｖ（＝４０×０．５）が小さくなるが、接点が溶着していれば、商用系統電圧が４０Ｖ、パワーコンディショナの出力電圧が４０Ｖと検知され、差分の絶対値｜Ｅｓｄ．ｒｍｓ−Ｅｕｗ．ｒｍｓ｜＝０Ｖに対して比較値２０Ｖ（＝４０×０．５）が大きくなる。 For example, if the contacts are not welded, the commercial system voltage is detected as 0 V and the output voltage of the power conditioner is detected as 40 V when the commercial system is interrupted. Therefore, the reliability coefficient R = 0.5 (R is R <1 (Positive number), the absolute value of the difference | E sd. rms- E u. The comparison value 20V (= 40 × 0.5) is smaller than rms | = 40V, but if the contacts are welded, the commercial system voltage is detected as 40V, and the output voltage of the power conditioner is detected as 40V. Absolute value | E sd. rms- E u. The comparison value 20V (= 40 × 0.5) increases with respect to rms | = 0V.
例えば、接点が溶着していなければ、商用系統電圧が１００Ｖ、パワーコンディショナの出力電圧が０Ｖと検知されるので、信頼係数Ｒ＝０．５（Ｒは、Ｒ＜１の正数）とすれば、差分の絶対値｜Ｅｓｄ．ｒｍｓ−Ｅｕｗ．ｒｍｓ｜＝１００Ｖに対して比較値５０Ｖ（＝１００×０．５）が小さくなるが、接点が溶着していれば、商用系統電圧が１００Ｖ、パワーコンディショナの出力電圧が１００Ｖと検知され、差分の絶対値｜Ｅｓｄ．ｒｍｓ−Ｅｕｗ．ｒｍｓ｜＝０Ｖに対して比較値５０Ｖ（＝１００×０．５）が大きくなる。 For example, if the contacts are not welded, the commercial system voltage is detected as 100 V and the output voltage of the power conditioner is detected as 0 V. Therefore, the reliability coefficient is R = 0.5 (R is a positive number of R <1). The absolute value of the difference | E sd. rms- E u. The comparison value 50V (= 100 × 0.5) is smaller than rms | = 100V, but if the contacts are welded, the commercial system voltage is detected as 100V, and the output voltage of the power conditioner is detected as 100V. Absolute value | E sd. rms- E u. The comparison value 50V (= 100 × 0.5) increases with respect to rms | = 0V.
ステップＳ１５で、差分の絶対値｜Ｅｓｄ．ｒｍｓ−Ｅｕｗ．ｒｍｓ｜よりも基準電圧Ｅｃｈｋに信頼係数ｘを掛けた値の方が大きいと判定されると、系統連系用リレーＲｙ１の接点が溶着していると判定して、メモリ素子に設定されたエラーフラグ記憶領域にフラグをセットし（Ｓ１７）、差分の絶対値｜Ｅｓｄ．ｒｍｓ−Ｅｕｗ．ｒｍｓ｜よりも基準電圧Ｅｃｈｋに信頼係数ｘを掛けた値の方が小さいと判定されると、系統連系用リレーＲｙ１が正常であると判定して、メモリ素子に設定されたエラーフラグ記憶領域のフラグをリセットする（Ｓ１６）。 In step S15, the absolute value of the difference | E sd. rms- E u. If it is determined that the value obtained by multiplying the reference voltage E chk by the reliability coefficient x is larger than the rms |, it is determined that the contact of the grid interconnection relay Ry1 is welded, and the value is set in the memory element. A flag is set in the error flag storage area (S17), and the absolute value of the difference | E sd. rms- E u. If it is determined that the value obtained by multiplying the reference voltage E chk by the reliability coefficient x is smaller than the rms |, it is determined that the grid interconnection relay Ry1 is normal, and the error flag set in the memory element is stored. The area flag is reset (S16).
遅延時間Ｔｃｈｋが商用系統周波数，あるいは，自立系統周波数の３周期（ｎ＝３）に設定され、少なくとも３周期の間のサンプリング値に基づいて実効値が算出されるように構成されているが、遅延時間Ｔｃｈｋは複数周期に設定されていればよく、３周期に限るものではない。 The delay time T chk is set to 3 periods (n = 3) of the commercial system frequency or the independent system frequency, and the effective value is calculated based on the sampling value during at least 3 periods. The delay time T chk only needs to be set to a plurality of periods, and is not limited to three periods.
パワーコンディショナＰＣＳの出力電圧や出力電流、商用系統電圧を検知するための回路素子は本来パワーコンディショナＰＣＳの制御に必要な回路素子であるので、系統連系用リレーＲｙ２の溶着を判定するために別途のセンサや回路素子を準備する必要はない。 Since the circuit elements for detecting the output voltage, output current, and commercial system voltage of the power conditioner PCS are originally circuit elements necessary for controlling the power conditioner PCS, in order to determine the welding of the grid interconnection relay Ry2. There is no need to prepare a separate sensor or circuit element.
本発明による系統連系用リレーの異常検出方法では、交流負荷Ｒｕｗが接続されているか否かに関わらず、また商用系統電圧の有無に関わらず、確実に系統連系用リレーの接点が溶着異常であるか否かが検出できるようになる。 In the abnormality detection method for the grid interconnection relay according to the present invention, the grid interconnection relay contact is reliably welded regardless of whether or not the AC load R uw is connected and whether or not the commercial grid voltage is present. Whether or not there is an abnormality can be detected.
以上説明した実施形態では、パワーコンディショナＰＣＳの出力が単相である場合を例に本発明を説明したが、本発明はパワーコンディショナＰＣＳの出力が３相であり、系統連系用リレーＲｙ１の接点がＳｕ，Ｓｖ，Ｓｗの３接点で構成される場合も適用可能である。 In the embodiment described above, the present invention has been described by taking the case where the output of the power conditioner PCS is a single phase as an example. However, the present invention has a three-phase output of the power conditioner PCS, and the grid interconnection relay Ry1. This is also applicable to the case where the contacts are composed of three contacts S u , S v , and S w .
以上の実施形態は、本発明による系統連系用リレーの異常検出方法及びパワーコンディショナの一例に過ぎず、該記載により本発明の技術的範囲が限定されるものではなく、本発明の作用効果が奏される限り、具体的な制御アルゴリズムは適宜変更設計可能なことは言うまでもない。 The above embodiment is merely an example of an abnormality detection method and a power conditioner for a grid interconnection relay according to the present invention, and the technical scope of the present invention is not limited by the description, and the operational effects of the present invention Needless to say, the specific control algorithm can be changed and designed as appropriate as long as the above is achieved.
１：分散型電源
２：ＤＣ／ＤＣコンバータ
３：ＤＣ／ＡＣインバータ
４：ＬＣフィルタ
５：制御装置
５ａ：コンバータ制御部
５ｂ：インバータ制御部
５ｃ：異常検出処理部
ＰＣＳ：パワーコンディショナ
Ｒｙ１：系統連系用リレー
Ｒｙ２：自立系統用リレー
Ｓｕ，Ｓｗ：接点
1: distributed power supply 2: DC / DC converter 3: DC / AC inverter 4: LC filter 5: control device 5a: converter control unit 5b: inverter control unit 5c: abnormality detection processing unit PCS: power conditioner Ry1: system connection System relay Ry2: independent system relays S u , S w : contacts
Claims (5)
商用系統電圧の有無を判定する商用系統電圧判定処理と、
前記商用系統電圧判定処理の結果に基づいて、異常検出時の前記パワーコンディショナの出力電圧及び前記系統連系用リレーの異常判定のための基準電圧を異なる値に設定する電圧設定処理と、
前記系統連系用リレーの接点が開成制御された状態で、前記パワーコンディショナの出力電圧と商用系統電圧との差分と、前記基準電圧に所定の信頼係数を掛けた値との大小関係に基づいて前記系統連系用リレーの異常判定を行なう異常検出処理と、
を実行する異常検出処理部を備えている系統連系用リレーの異常検出装置。 Built in a power conditioner that can be switched to either grid-connected operation linked to the commercial system via the grid-connected relay or autonomous operation that supplies power to the independent system via the independent-system relay. A grid connection relay abnormality detection device that detects a grid connection relay abnormality when switching to operation,
Commercial system voltage determination processing for determining the presence or absence of commercial system voltage;
Based on the result of the commercial grid voltage determination process, a voltage setting process for setting the output voltage of the power conditioner at the time of abnormality detection and a reference voltage for abnormality determination of the grid interconnection relay to different values;
Based on the magnitude relationship between the difference between the output voltage of the power conditioner and the commercial grid voltage and the value obtained by multiplying the reference voltage by a predetermined reliability coefficient in a state where the contact of the grid interconnection relay is controlled to open. Abnormality detection processing for determining abnormality of the grid interconnection relay,
The abnormality detection apparatus of the grid connection relay provided with the abnormality detection process part which performs.
請求項１から４の何れかに記載の系統連系用リレーの異常検出装置が前記制御装置に組み込まれているパワーコンディショナ。
Single-phase or three-phase equipped with a control device capable of switching between grid-connected operation linked to the commercial system via the grid-connected relay and independent operation supplying power to the independent system via the independent-system relay It is a power conditioner of
A power conditioner in which the abnormality detection device for a grid interconnection relay according to any one of claims 1 to 4 is incorporated in the control device.
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| US11616363B2 (en) | 2020-09-11 | 2023-03-28 | Kabushiki Kaisha Toshiba | Electronic apparatus with detection of an islanding condition |
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| JP6333746B2 (en) * | 2015-01-27 | 2018-05-30 | 株式会社椿本チエイン | SWITCH DEVICE, POWER CONVERSION DEVICE, AND SWITCH SHORT JUDGMENT METHOD |
| US9970988B2 (en) * | 2015-11-20 | 2018-05-15 | Tabuchi Electric Co., Ltd. | Relay abnormality detection device and power conditioner |
| JP6774893B2 (en) * | 2017-03-03 | 2020-10-28 | 田淵電機株式会社 | Power converter for grid interconnection with self-sustaining operation function |
| JP6842953B2 (en) * | 2017-03-03 | 2021-03-17 | 田淵電機株式会社 | Power converter |
| WO2018179234A1 (en) * | 2017-03-30 | 2018-10-04 | 株式会社 東芝 | H-bridge converter and power conditioner |
| JP6849076B2 (en) * | 2017-08-31 | 2021-03-24 | 株式会社村田製作所 | Photovoltaic system, power conditioner |
| JP7382763B2 (en) * | 2019-08-28 | 2023-11-17 | 新電元工業株式会社 | Power conditioning system and power conditioning system diagnosis method |
| JP7315773B2 (en) * | 2019-08-28 | 2023-07-26 | 京セラ株式会社 | POWER CONTROL DEVICE AND CONTROL METHOD OF POWER CONTROL DEVICE |
| JP7334760B2 (en) * | 2021-05-20 | 2023-08-29 | 株式会社村田製作所 | power conditioner |
| CN116165529B (en) * | 2022-12-20 | 2023-09-15 | 上海百竹成航新能源有限责任公司 | Relay adhesion detection method, electronic equipment and energy storage inverter system |
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| JP5472415B2 (en) * | 2012-09-21 | 2014-04-16 | 株式会社安川電機 | Power converter |
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