JP5619410B2

JP5619410B2 - Inspection method and inspection apparatus

Info

Publication number: JP5619410B2
Application number: JP2009285911A
Authority: JP
Inventors: 小林　健二; 健二小林; 雄作宮田; 竜太斎藤
Original assignee: Hioki EE Corp
Current assignee: Hioki EE Corp
Priority date: 2009-12-17
Filing date: 2009-12-17
Publication date: 2014-11-05
Anticipated expiration: 2029-12-17
Also published as: JP2011127983A

Description

本発明は、太陽光発電ユニット等を測定対象体としてそのような測定対象体の絶縁状態を検査する検査方法および検査装置に関するものである。 The present invention relates to an inspection method and an inspection apparatus photovoltaic unit such as a measured object to inspect the insulation state of the measured object, such as Teso.

例えば、特開２００１−１０２６０９号公報には、光電変換装置（太陽電池モジュール）の特性測定装置が開示されている。この特性測定装置は、パルスソーラーシミュレータと絶縁抵抗測定装置とを備え、太陽電池モジュールのＩＶ特性の測定処理、および絶縁抵抗値の測定処理を実施可能に構成されている。この場合、この特性測定装置による絶縁抵抗値の測定処理に際しては、まず、パルスソーラーシミュレータに代えて、絶縁抵抗測定装置を太陽電池モジュールに接続する。この際には、絶縁抵抗測定装置内において太陽電池モジュールのプラス端子とマイナス端子とが短絡された状態で両出力端子（両端子）が絶縁抵抗測定装置に接続される。次いで、太陽電池モジュールの両出力端子とそのフレームとの間に検査用電圧を印加した状態において両出力端子とフレームとの間の抵抗値を測定する。これにより、測定対象の太陽電池モジュールの絶縁抵抗値が測定される。なお、上記の絶縁抵抗値の測定処理は、ＪＩＳ−Ｃ８９１８（結晶系太陽電池モジュール）や、ＪＩＳ−Ｃ８９３９（アモルファス太陽電池モジュール）における「絶縁」の項目において規定された手順に準じている。 For example, Japanese Patent Application Laid-Open No. 2001-102609 discloses a characteristic measuring device for a photoelectric conversion device (solar cell module). This characteristic measurement device includes a pulse solar simulator and an insulation resistance measurement device, and is configured to be able to perform a measurement process of an IV characteristic of a solar cell module and a measurement process of an insulation resistance value. In this case, in the process of measuring the insulation resistance value by this characteristic measuring device, first, instead of the pulse solar simulator, the insulation resistance measuring device is connected to the solar cell module. At this time, both output terminals (both terminals) are connected to the insulation resistance measuring device in a state where the plus terminal and the minus terminal of the solar cell module are short-circuited in the insulation resistance measuring device. Next, the resistance value between the output terminals and the frame is measured in a state where the inspection voltage is applied between the output terminals of the solar cell module and the frame. Thereby, the insulation resistance value of the solar cell module to be measured is measured. In addition, the measurement process of said insulation resistance value is based on the procedure prescribed | regulated in the item of "insulation" in JIS-C8918 (crystalline solar cell module) and JIS-C8939 (amorphous solar cell module).

特開２００１−１０２６０９号公報（第３頁、第１図）JP 2001-102609 A (page 3, FIG. 1)

ところが、従来の特性測定装置には、以下の問題点が存在する。すなわち、従来の特性測定装置では、相互に短絡した状態の両出力端子とフレームとの間の絶縁抵抗値を絶縁抵抗測定装置によって測定する構成が採用されている。この場合、従来の特性測定装置は、製品開発時や出荷前検査時などに太陽電池モジュールのＩＶ特性や絶縁抵抗値を測定するのを想定した構成となっている。一方、太陽電池モジュールの光電変換特性の向上に伴い、近年の太陽光発電システムでは、太陽電池モジュールの使用枚数や接続形態によっては、太陽光発電ユニットから数百ボルトの比較的高い電圧値で数千ワットの大きな電力を出力することが可能となっている。したがって、事故発生を防止するために、太陽電池モジュールを屋外に設置した状態（太陽光発電ユニットとして複数枚の太陽電池モジュールを設置した状態）においても、その絶縁状態が良好であるか否かを定期的に検査する必要が生じている。 However, the conventional characteristic measuring apparatus has the following problems. That is, in the conventional characteristic measuring apparatus, the structure which measures the insulation resistance value between both the output terminals in the state short-circuited with the flame | frame with an insulation resistance measuring apparatus is employ | adopted. In this case, the conventional characteristic measuring apparatus is configured to measure the IV characteristic and the insulation resistance value of the solar cell module at the time of product development or inspection before shipment. On the other hand, along with the improvement of the photoelectric conversion characteristics of solar cell modules, in recent photovoltaic power generation systems, depending on the number of solar cell modules used and the connection form, the number of solar cell modules at a relatively high voltage value of several hundred volts is several. It is possible to output a large power of 1,000 watts. Therefore, in order to prevent the occurrence of an accident, whether or not the insulation state is good even in a state where the solar cell module is installed outdoors (a state where a plurality of solar cell modules are installed as a solar power generation unit). There is a need to inspect regularly.

この場合、現時点においては、設置状態における太陽光発電ユニット（太陽電池モジュール）の絶縁状態を測定する方法に関する明確な規定（測定規格）が存在しないため、一般的には、従来の特性測定装置による絶縁抵抗測定方法と同様の手順（以下、「従来の絶縁抵抗測定方法」ともいう）に従い、太陽電池モジュールの両出力端子を短絡した状態において絶縁抵抗値を測定している。しかしながら、屋外に設置した状態における太陽光発電ユニットの絶縁抵抗値を従来の絶縁抵抗測定方法に従って測定する場合、太陽電池モジュールに対して太陽光が照射されている日中においては、太陽光発電ユニットの両出力端子間に数百ボルトの電位差が生じた状態となっている。このため、そのような出力端子を短絡するのが非常に危険であるばかりでなく、絶縁抵抗測定装置の破損を招くおそれもある。 In this case, at present, there is no clear rule (measurement standard) regarding a method for measuring the insulation state of the photovoltaic power generation unit (solar cell module) in the installed state. In accordance with the same procedure as the insulation resistance measurement method (hereinafter also referred to as “conventional insulation resistance measurement method”), the insulation resistance value is measured in a state where both output terminals of the solar cell module are short-circuited. However, when measuring the insulation resistance value of the photovoltaic power generation unit in the state of being installed outdoors according to the conventional insulation resistance measurement method, the photovoltaic power generation unit is used during the daytime when the solar cell module is irradiated with sunlight. There is a potential difference of several hundred volts between the two output terminals. For this reason, it is not only very dangerous to short-circuit such output terminals, but also the insulation resistance measuring device may be damaged.

したがって、設置状態の太陽光発電ユニットの絶縁抵抗値を従来の絶縁抵抗測定方法に従って測定する際には、太陽電池モジュールを遮光布等で覆うか、或いは、太陽光が照射されるおそれのない夜間に測定作業を実施する必要がある。このため、太陽光発電ユニットが設置された高所において、太陽電池モジュールを遮光布によって覆う作業が非常に危険で煩雑であるというという問題点がある。また、このような問題が生じるのを回避するために絶縁抵抗の測定を夜間に実施する場合には、日暮れから夜明けまでの限られた時間内において、絶縁抵抗測定装置を太陽光発電ユニットに接続する作業、絶縁抵抗の測定作業、および太陽光発電ユニットから絶縁抵抗測定装置を取り外す作業を完了させなくてはならないばかりでなく、太陽光発電ユニットが設置された高所において夜間に接続作業や取り外し作業を実施するのが非常に危険であるという問題点がある。 Therefore, when measuring the insulation resistance value of the installed photovoltaic power generation unit according to the conventional insulation resistance measurement method, the solar cell module is covered with a light-shielding cloth or the like at night when there is no possibility of being irradiated with sunlight. It is necessary to carry out measurement work. For this reason, in the high place where the photovoltaic power generation unit is installed, there is a problem that the operation of covering the solar cell module with the light shielding cloth is very dangerous and complicated. In addition, when measuring insulation resistance at night in order to avoid such problems, connect the insulation resistance measuring device to the photovoltaic power generation unit within a limited time from sunset to dawn. Work, insulation resistance measurement, and removal of the insulation resistance measuring device from the solar power generation unit must be completed, as well as connection and removal at night in a high place where the solar power generation unit is installed. There is a problem that it is very dangerous to carry out the work.

本発明は、かかる問題点に鑑みてなされたものであり、測定対象体の絶縁抵抗値を任意の時点において安全に測定して測定対象体の絶縁状態を任意の時点において安全に検査し得る検査方法および検査装置を提供することを主目的とする。 The present invention has been made in view of such problems, and can inspect the insulation resistance value of a measurement object safely at an arbitrary time point and safely inspect the insulation state of the measurement object at an arbitrary time point. The main object is to provide a method and an inspection device .

上記目的を達成すべく請求項１記載の検査方法は、起電力を有する測定対象体における一対の出力端子のいずれか一方と接地部位との間に検査用電圧を印加した状態において当該一方の出力端子と当該接地部位との間を流れる電流の第１の電流値を測定すると共に、前記一方の出力端子と前記接地部位との間に対する前記検査用電圧の印加を停止した状態において当該一方の出力端子と当該接地部位との間を流れる電流の第２の電流値を測定し、前記第１の電流値から前記第２の電流値を差し引いた第３の電流値と前記検査用電圧の電圧値とに基づいて前記一方の出力端子と前記接地部位との間の絶縁抵抗値を演算する絶縁抵抗測定方法に従って前記一対の出力端子の各々と当該接地部位との間の当該絶縁抵抗値をそれぞれ演算し、当該演算した両絶縁抵抗値が予め規定した基準値を超えているときに前記測定対象体の前記接地部位との間の絶縁状態を良好と検査する。 In order to achieve the above object, the inspection method according to claim 1 is the output of one of the pair of output terminals in the measuring object having an electromotive force in a state in which the inspection voltage is applied between the grounded portion. Measuring the first current value of the current flowing between the terminal and the grounded portion, and stopping the application of the inspection voltage between the one output terminal and the grounded portion. A second current value of a current flowing between the terminal and the grounding part is measured, and a third current value obtained by subtracting the second current value from the first current value and a voltage value of the inspection voltage And calculating the insulation resistance value between each of the pair of output terminals and the ground part according to the insulation resistance measurement method for calculating the insulation resistance value between the one output terminal and the ground part based on And the operation The insulation state between the ground portion of the measured object inspecting good when both the insulation resistance value exceeds a predefined reference value.

また、請求項２記載の検査方法は、請求項１記載の検査方法において、前記一方の出力端子と前記接地部位との間に印加する前記検査用電圧の前記電圧値を変更しつつ、当該変更した前記各検査用電圧を印加した状態において当該一方の出力端子と当該接地部位との間を流れる各電流値をそれぞれ測定すると共に、前記変更した各電圧値と前記測定した各電流値とに基づいて当該一方の出力端子と当該接地部位との間を流れる電流値を直線近似処理して前記第１の電流値を取得する。 The inspection method according to claim 2, wherein, in the inspection method according to claim 1, wherein, while changing the voltage value of the test voltage applied between the ground portion and the one output terminal, the change And measuring each current value flowing between the one output terminal and the grounded portion in a state where each test voltage is applied, and based on the changed voltage value and the measured current value. Then, the current value flowing between the one output terminal and the grounding part is linearly approximated to obtain the first current value.

また、請求項３記載の検査方法は、請求項１または２記載の検査方法において、第１の抵抗および当該第１の抵抗よりも大きな抵抗値の第２の抵抗のうちの当該第２の抵抗を前記一方の出力端子と前記接地部位との間に接続させると共に前記検査用電圧を印加した状態において測定した当該一方の出力端子と当該接地部位との間を流れる電流の第４の電流値が予め規定された基準電流値を下回っているときに、前記第２の抵抗に代えて前記第１の抵抗を前記一方の出力端子と前記接地部位との間に接続させると共に前記検査用電圧を印加した状態において前記測定した前記第１の電流値に基づいて前記絶縁抵抗値を演算する。 The inspection method according to claim 3 is the inspection method according to claim 1 or 2 , wherein the second resistance of the first resistance and the second resistance having a larger resistance value than the first resistance. Is connected between the one output terminal and the grounding portion, and a fourth current value of a current flowing between the one output terminal and the grounding portion measured in a state where the inspection voltage is applied is When the current value is lower than a predetermined reference current value, instead of the second resistor, the first resistor is connected between the one output terminal and the ground portion and the inspection voltage is applied. In this state, the insulation resistance value is calculated based on the measured first current value.

また、請求項４記載の検査装置は、起電力を有する測定対象体における一対の出力端子のいずれか一方と接地部位との間に検査用電圧を印加する電源部、前記一方の出力端子と前記接地部位との間を流れる電流の電流値を測定する測定部、および前記電源部によって前記検査用電圧が印加されている状態において前記測定部によって測定された前記電流値と前記検査用電圧の電圧値とに基づいて前記一方の出力端子と前記接地部位との間の絶縁抵抗値を演算する制御部とを備え、前記制御部が、前記電源部によって前記検査用電圧が印加されている状態において前記測定部によって測定された当該一方の出力端子と当該接地部位との間を流れる電流の第１の電流値から、前記検査用電圧の印加が停止されている状態において前記測定部によって測定された当該一方の出力端子と当該接地部位との間を流れる電流の第２の電流値を差し引いた第３の電流値と前記検査用電圧の電圧値とに基づいて当該一方の出力端子と当該接地部位との間の絶縁抵抗値を演算する絶縁抵抗測定方法に従って前記一対の出力端子の各々と当該接地部位との間の当該絶縁抵抗値をそれぞれ演算し、当該演算した両絶縁抵抗値が予め規定した基準値を超えているときに前記測定対象体の前記接地部位との間の絶縁状態を良好と検査する。 The inspection apparatus according to claim 4 is a power supply unit that applies a test voltage between any one of a pair of output terminals and a grounding part in a measurement object having electromotive force, the one output terminal, A measuring unit for measuring a current value of a current flowing between the ground part and the voltage of the current value and the testing voltage measured by the measuring unit in a state where the testing voltage is applied by the power source unit; A control unit that calculates an insulation resistance value between the one output terminal and the grounding part based on the value, and the control unit is in a state where the inspection voltage is applied by the power supply unit. From the first current value of the current flowing between the one output terminal measured by the measurement unit and the grounded part, the measurement unit applies the test voltage in a state where the application of the inspection voltage is stopped. And it measured the one output terminal based on the voltage value of the third current value and the test voltage obtained by subtracting the second current value of the current flowing between the one output terminal and the ground site the According to an insulation resistance measurement method for calculating an insulation resistance value between the ground part and the insulation part, the insulation resistance value between each of the pair of output terminals and the ground part is calculated. When the predetermined reference value is exceeded, the insulation state between the measurement object and the grounding part is inspected as good.

さらに、請求項５記載の検査装置は、請求項４記載の検査装置において、前記電源部が、前記検査用電圧の前記電圧値を変更可能に構成され、前記制御部が、前記電源部を制御して前記一方の出力端子と前記接地部位との間に印加する前記検査用電圧の前記電圧値を変更させつつ、当該変更した前記各検査用電圧が印加されている状態において前記測定部によってそれぞれ測定された当該一方の出力端子と当該接地部位との間を流れる各電流値と、前記印加させた検査用電圧の各電圧値とに基づいて当該一方の出力端子と当該接地部位との間を流れる電流値を直線近似処理して前記第１の電流値を取得する。 Further, the inspection apparatus according to claim 5, wherein, in the inspection apparatus according to claim 4, wherein the power supply unit is capable of changing the voltage value of the test voltage, the control unit, controls the power supply unit Then, while changing the voltage value of the inspection voltage applied between the one output terminal and the grounding portion, the measurement unit in the state where the changed inspection voltage is applied, respectively. Based on the measured current values flowing between the one output terminal and the grounded portion and the voltage values of the applied inspection voltage, between the one output terminal and the grounded portion. The first current value is obtained by linearly approximating the flowing current value.

また、請求項６記載の検査装置は、請求項４または５記載の検査装置において、第１の抵抗、当該第１の抵抗よりも大きな抵抗値の第２の抵抗、および当該第１の抵抗と当該第２の抵抗とのいずれかを前記一方の出力端子と前記接地部位との間に接続する接続切替え部を備え、前記制御部が、前記接続切替え部を制御して前記第２の抵抗を接続させると共に前記電源部によって前記検査用電圧が印加されている状態において前記測定部によって測定された当該一方の出力端子と当該接地部位との間を流れる電流の第４の電流値が予め規定された基準電流値を下回っているときに、前記接続切替え部を制御して前記第１の抵抗を接続させると共に前記検査用電圧が印加されている状態において前記測定部によって測定された前記第１の電流値に基づいて前記絶縁抵抗値を演算する。 The inspection apparatus of claim 6, wherein, in the inspection apparatus according to claim 4 or 5, wherein the first resistor, a second resistor of high resistance value than the first resistor, and the first resistor and A connection switching unit that connects any one of the second resistors between the one output terminal and the grounding portion; and the control unit controls the connection switching unit to control the second resistance. A fourth current value of the current flowing between the one output terminal and the ground portion measured by the measurement unit in a state where the inspection voltage is applied by the power supply unit is defined in advance. When the voltage is lower than the reference current value, the first switching unit is controlled to connect the first resistor and the first voltage measured by the measuring unit in a state where the test voltage is applied. Current value Zui by computing the insulation resistance value.

請求項１記載の検査方法、および前記４記載の検査装置によれば、一方の出力端子と接地部位との間に検査用電圧を印加した状態において一方の出力端子と接地部位との間を流れる電流の第１の電流値を測定すると共に、一方の出力端子と接地部位との間に対する検査用電圧の印加を停止した状態において一方の出力端子と接地部位との間を流れる電流の第２の電流値を測定し、第１の電流値から第２の電流値を差し引いた第３の電流値と検査用電圧の電圧値とに基づいて一方の出力端子と接地部位との間の絶縁抵抗値を演算することにより、一対の出力端子を短絡することなく絶縁抵抗を検査することができるため、両出力端子の間に大きな電位差が生じている状態であっても、測定作業（検査作業）を安全に実施することができる。また、「起電力を有する測定対象体」としての例えば太陽光発電ユニットを測定対象とする場合においても、高所に設置されている太陽光発電ユニットを遮光布で覆う作業が不要となり、太陽光の照射を避けて夜間に測定作業を実施する必要もないことから、太陽光発電ユニットの絶縁抵抗値を安全かつ簡便に測定（太陽光発電ユニットを安全かつ簡便に検査）することができる。また、両出力端子の間に生じた電位差に起因する電流の電流値を差し引いているため、太陽光発電ユニットの絶縁抵抗値を正確に測定（太陽光発電ユニットを正確に検査）することができる。 According to the inspection method according to claim 1 and the inspection device according to claim 4, the current flows between the one output terminal and the ground portion in a state where the inspection voltage is applied between the one output terminal and the ground portion. A first current value of the current is measured, and a second current flowing between the one output terminal and the ground portion in a state where the application of the inspection voltage between the one output terminal and the ground portion is stopped is measured. Insulation resistance value between one output terminal and the grounding part based on the third current value obtained by measuring the current value and subtracting the second current value from the first current value and the voltage value of the test voltage Since the insulation resistance can be inspected without short-circuiting the pair of output terminals, the measurement work (inspection work) can be carried out even when there is a large potential difference between the two output terminals. It can be implemented safely. In addition, even when a photovoltaic power generation unit, for example, as a “measurement object having an electromotive force” is a measurement target, it is not necessary to cover the photovoltaic power generation unit installed at a high place with a light shielding cloth. Therefore, it is not necessary to carry out measurement work at night while avoiding the irradiation of the solar cell, so that the insulation resistance value of the photovoltaic power generation unit can be measured safely and simply (safety and simple inspection of the photovoltaic power generation unit) . Moreover, since the current value of the current resulting from the potential difference generated between the two output terminals is subtracted, the insulation resistance value of the photovoltaic power generation unit can be accurately measured (the photovoltaic power generation unit is accurately inspected). .

また、この検査方法および検査装置によれば、上記の絶縁抵抗測定方法に従って一対の出力端子の各々と接地部位との間の絶縁抵抗値をそれぞれ測定し、測定した両絶縁抵抗値が予め規定した基準値を超えているときに測定対象体の接地部位との間の絶縁状態を良好と検査することにより、測定対象体の両出力端子間に断線が生じていたとしても、測定対象体の各部（一方の出力端子の側、および他方の出力端子の側）における絶縁状態の良否を確実に検査することができる。 Further , according to the inspection method and the inspection apparatus, the insulation resistance value between each of the pair of output terminals and the ground portion is measured according to the insulation resistance measurement method, and the measured both insulation resistance values are defined in advance. Even if a disconnection occurs between both output terminals of the measurement object by checking that the insulation state between the measurement object and the grounding part is good when the reference value is exceeded, each part of the measurement object The quality of the insulation state on one output terminal side and the other output terminal side can be reliably inspected.

また、請求項２記載の検査方法、および請求項５記載の検査装置によれば、一方の出力端子と接地部位との間に印加する検査用電圧の電圧値を変更しつつ、変更した各検査用電圧を印加した状態において一方の出力端子と接地部位との間を流れる各電流値をそれぞれ測定すると共に、変更した各電圧値と測定した各電流値とに基づいて一方の出力端子と接地部位との間を流れる電流値を直線近似処理して第１の電流値を取得することにより、いずれか１つの電圧値の検査用電圧を印加して測定した電流値に基づいて絶縁抵抗値を演算する方法および構成と比較して、測定対象体の絶縁抵抗値を一層正確に測定することができる。 According to the inspection method of claim 2 and the inspection apparatus of claim 5, each inspection changed while changing the voltage value of the inspection voltage applied between the one output terminal and the grounding part. Each current value flowing between one output terminal and the grounding part in a state where a working voltage is applied is measured, and one output terminal and the grounding part are measured based on each changed voltage value and each measured current value. By calculating a linear approximation of the current value flowing between the two and obtaining the first current value, the insulation resistance value is calculated based on the current value measured by applying one of the test voltages. As compared with the method and configuration, the insulation resistance value of the measurement object can be measured more accurately.

また、請求項３記載の検査方法、および請求項６記載の検査装置によれば、第１の抵抗よりも大きな抵抗値の第２の抵抗を接続すると共に一方の出力端子と接地部位との間に検査用電圧を印加した状態において測定した電流の第４の電流値が予め規定された基準電流値を下回っているときに、抵抗値が小さい第１の抵抗を接続した状態において測定した第１の電流値に基づいて絶縁抵抗値を演算することにより、測定対象体に絶縁不良が生じていたとしても、測定対象体の出力端子と接地部位との間に生じている電位差（測定対象体の起電力）に起因して大きな電流が流れることがないため、絶縁抵抗測定装置が破損する事態を回避することができるだけでなく、絶縁抵抗値の測定に際しては、抵抗値が小さい第１の抵抗を接続した状態において電流値を測定できるため、測定対象体の絶縁抵抗値を正確に測定することができる。 The inspection method according to claim 3, wherein, and according to the inspection apparatus according to claim 6, between the ground site and the one output terminal with than the first resistor connecting a second resistor of high resistance value When the fourth current value of the current measured with the test voltage applied is lower than a predetermined reference current value, the first measured with the first resistor having a small resistance value connected. By calculating the insulation resistance value based on the current value, the potential difference generated between the output terminal of the measurement object and the grounding portion (even if the measurement object has an insulation failure) Since a large current does not flow due to the electromotive force), it is possible not only to avoid the situation where the insulation resistance measuring device is damaged, but also when measuring the insulation resistance value, the first resistance having a small resistance value is used. Connected Because it can measure the current value each, the insulation resistance value of the measured object can be accurately measured.

絶縁検査装置１の構成を示す構成図である。1 is a configuration diagram showing a configuration of an insulation inspection device 1. 電源部２ａの構成を示す構成図である。It is a block diagram which shows the structure of the power supply part 2a.

以下、検査方法および検査装置の実施の形態について、添付図面を参照して説明する。 Hereinafter, embodiments of the test査方method and inspection apparatus will be described with reference to the accompanying drawings.

最初に、絶縁検査装置１の構成について説明する。 First, the configuration of the insulation inspection apparatus 1 will be described.

図１に示す絶縁検査装置１は、検査装置の一例であって、測定対象体としての太陽光発電ユニット５０の絶縁抵抗値を測定して、その絶縁状態を検査可能に構成されている。この場合、太陽光発電ユニット５０は、「起電力を有する測定対象体」の一例であって、数枚から数十枚の太陽電池モジュールが直列接続された状態で屋根上等に設置されている。この太陽光発電ユニット５０は、一対の出力端子５０ａ，５０ｂを備え、一例として、最大で１０ｋＷ程度の電力を出力可能に構成されている。なお、この太陽光発電ユニット５０における各太陽電池モジュールに対して太陽光が照射されているときには、一例として、出力端子５０ａ（プラス端子）と出力端子５０ｂ（マイナス端子）との間の電位差が最大で３００Ｖ程度となる。 An insulation inspection apparatus 1 shown in FIG. 1 is an example of an inspection apparatus , and is configured to measure an insulation resistance value of a photovoltaic power generation unit 50 as a measurement object and to inspect the insulation state. In this case, the photovoltaic power generation unit 50 is an example of a “measurement object having an electromotive force”, and is installed on a roof or the like with several to several tens of solar cell modules connected in series. . The solar power generation unit 50 includes a pair of output terminals 50a and 50b, and is configured to be able to output power of about 10 kW at the maximum as an example. In addition, when sunlight is radiated to each solar cell module in the solar power generation unit 50, as an example, the potential difference between the output terminal 50a (plus terminal) and the output terminal 50b (minus terminal) is maximum. It becomes about 300V.

一方、絶縁検査装置１は、電源部２、測定部３、抵抗４ａ，４ｂ、接続端子５ａ〜５ｃ、スイッチ６，７、制御部８および記憶部９を備えている。電源部２は、制御部８からの制御信号Ｓ３に従って検査用電圧を出力する。この場合、この絶縁検査装置１では、検査用電圧の電圧値を多段階に変化させることが可能な電圧値可変型の直流電圧源（図示せず）を備えて電源部２が構成されている。測定部３は、制御部８からの制御信号Ｓ４に従って太陽光発電ユニット５０の出力端子５０ａ，５０ｂのいずれか一方と接地部位との間を流れる電流の電流値を測定し、その測定結果を測定値データＤ１として出力する。 On the other hand, the insulation inspection apparatus 1 includes a power supply unit 2, a measurement unit 3, resistors 4 a and 4 b, connection terminals 5 a to 5 c, switches 6 and 7, a control unit 8, and a storage unit 9. The power supply unit 2 outputs a test voltage in accordance with a control signal S3 from the control unit 8. In this case, the insulation inspection apparatus 1 includes a power supply unit 2 including a voltage value variable type DC voltage source (not shown) capable of changing the voltage value of the inspection voltage in multiple stages. . The measurement unit 3 measures the current value of the current flowing between one of the output terminals 50a and 50b of the photovoltaic power generation unit 50 and the grounded part in accordance with the control signal S4 from the control unit 8, and measures the measurement result. Output as value data D1.

抵抗４ａ，４ｂは、検査用の抵抗であって、第１の抵抗および第２の抵抗に相当し、一例として、抵抗４ａが１ｋΩ程度の抵抗体で構成されると共に、抵抗４ｂが１ＭΩの抵抗体で構成されている。接続端子５ａ，５ｂは、太陽光発電ユニット５０における出力端子５０ａ，５０ｂにそれぞれ接続可能に構成され、接続端子５ｃは、接地部位（一例として、太陽光発電ユニット５０を設置した屋根の外板）に接続可能に構成されている。スイッチ６は、制御部８からの制御信号Ｓ１に従い、接続端子５ａ，５ｂのいずれか（すなわち、接続端子５ａ，５ｂが接続された出力端子５０ａ，５０ｂのいずれか）を電源部２に接続する。スイッチ７は、制御部８からの制御信号Ｓ２に従い、抵抗４ａ，４ｂのいずれかを測定部３と接地部位との間に接続する。 The resistors 4a and 4b are inspection resistors and correspond to a first resistor and a second resistor. As an example, the resistor 4a is formed of a resistor of about 1 kΩ, and the resistor 4b is a resistor of 1 MΩ. Consists of the body. The connection terminals 5a and 5b are configured to be connectable to the output terminals 50a and 50b of the photovoltaic power generation unit 50, respectively, and the connection terminal 5c is a ground portion (for example, the outer plate of the roof on which the photovoltaic power generation unit 50 is installed). It is configured to be connectable to. The switch 6 connects one of the connection terminals 5a and 5b (that is, one of the output terminals 50a and 50b to which the connection terminals 5a and 5b are connected) to the power supply unit 2 in accordance with the control signal S1 from the control unit 8. . The switch 7 connects any one of the resistors 4a and 4b between the measurement unit 3 and the grounded part in accordance with the control signal S2 from the control unit 8.

制御部８は、絶縁検査装置１を総括的に制御する。具体的には、制御部８は、スイッチ６に対して制御信号Ｓ１を出力して接続端子５ａ，５ｂのいずれか一方を電源部２に接続させると共に、スイッチ７に対して制御信号Ｓ２を出力して抵抗４ａ，４ｂのいずれか一方を測定部３と接地部位との間に接続させる。また、制御部８は、電源部２に対して制御信号Ｓ３を出力することによって検査用電圧の出力の開始および停止を制御すると共に、測定部３に対して制御信号Ｓ４を出力して電流値の測定処理を開始させる。さらに、制御部８は、測定部３から出力される測定値データＤ１に基づいて太陽光発電ユニット５０の絶縁抵抗値を演算すると共に、演算結果と、記憶部９に記憶されている基準値データＤ０とに基づき、太陽光発電ユニット５０の絶縁状態を検査する。記憶部９は、基準値データＤ０および測定値データＤ１や制御部８の動作プログラムを記憶する。 The control unit 8 comprehensively controls the insulation inspection apparatus 1. Specifically, the control unit 8 outputs a control signal S1 to the switch 6 to connect one of the connection terminals 5a and 5b to the power supply unit 2, and outputs a control signal S2 to the switch 7. Then, one of the resistors 4a and 4b is connected between the measurement unit 3 and the grounding part. In addition, the control unit 8 controls the start and stop of the output of the test voltage by outputting the control signal S3 to the power supply unit 2, and outputs the control signal S4 to the measurement unit 3 to output the current value. Start the measurement process. Further, the control unit 8 calculates the insulation resistance value of the photovoltaic power generation unit 50 based on the measurement value data D1 output from the measurement unit 3, and the calculation result and the reference value data stored in the storage unit 9. Based on D0, the insulation state of the photovoltaic power generation unit 50 is inspected. The storage unit 9 stores reference value data D0, measurement value data D1, and an operation program of the control unit 8.

次に、絶縁検査装置１による太陽光発電ユニット５０の検査方法について、添付図面を参照して説明する。 Next, the inspection method of the photovoltaic power generation unit 50 by the insulation inspection apparatus 1 will be described with reference to the attached drawings.

まず、太陽光発電ユニット５０の設置場所に絶縁検査装置１を携行し、太陽光発電ユニット５０の出力端子５０ａに接続端子５ａを接続すると共に、出力端子５０ｂに接続端子５ｂを接続し、かつ、太陽光発電ユニット５０が設置されている屋根の屋根板（金属部）に接続端子５ｃを接続する。次いで、図示しない操作部の開始スイッチを操作する。この際に、制御部８は、測定対象体（この例では、太陽光発電ユニット５０）の絶縁状態を検査する検査処理を開始する。この検査処理では、制御部８は、まず、スイッチ６に対して制御信号Ｓ１を出力して接続端子５ａを電源部２に接続させる。これにより、太陽光発電ユニット５０の出力端子５０ａ（プラス端子：「一方の出力端子」の一例）が接続端子５ａを介して電源部２に接続される。 First, the insulation inspection apparatus 1 is carried at the installation place of the solar power generation unit 50, the connection terminal 5a is connected to the output terminal 50a of the solar power generation unit 50, the connection terminal 5b is connected to the output terminal 50b, and The connection terminal 5c is connected to the roof plate (metal part) of the roof where the solar power generation unit 50 is installed. Next, a start switch of an operation unit (not shown) is operated. At this time, the control unit 8 starts an inspection process for inspecting the insulation state of the measurement object (in this example, the photovoltaic power generation unit 50). In this inspection process, the control unit 8 first outputs a control signal S1 to the switch 6 to connect the connection terminal 5a to the power supply unit 2. Thereby, the output terminal 50a (plus terminal: an example of “one output terminal”) of the photovoltaic power generation unit 50 is connected to the power supply unit 2 via the connection terminal 5a.

この場合、例えば、太陽光発電ユニット５０の出力端子５０ａと接地部位（この例では、屋根の外板）との間に絶縁不良が生じて、出力端子５０ａと接地部位との間の抵抗成分Ｒａの抵抗値が正常な絶縁状態よりも小さくなっている状態においては、太陽光発電ユニット５０の出力端子５０ａと接地部位との間に生じている電位差（太陽光発電ユニット５０の起電力）に起因して絶縁不良箇所を通じて出力端子５０ａと接地部位との間に大きな電流が流れて、絶縁検査装置１の破損を招くおそれがある。したがって、この絶縁検査装置１では、絶縁状態の検査の開始直後において、大きな抵抗値（この例では、１ＭΩ）の抵抗４ｂを測定部３と接地部位との間に接続することにより、出力端子５０ａと接地部位との間に絶縁不良が生じてたとしても、絶縁検査装置１が破損する事態を回避する構成が採用されている。 In this case, for example, an insulation failure occurs between the output terminal 50a of the photovoltaic power generation unit 50 and the ground part (in this example, the outer plate of the roof), and the resistance component Ra between the output terminal 50a and the ground part. In the state where the resistance value is smaller than the normal insulation state, it is caused by a potential difference (electromotive force of the photovoltaic power generation unit 50) generated between the output terminal 50a of the photovoltaic power generation unit 50 and the grounded portion. As a result, a large current flows between the output terminal 50a and the grounded portion through the defective insulation portion, which may cause damage to the insulation inspection apparatus 1. Therefore, in the insulation inspection apparatus 1, immediately after the start of the inspection of the insulation state, the resistance 4b having a large resistance value (1 MΩ in this example) is connected between the measurement unit 3 and the grounding portion, whereby the output terminal 50a. Even if there is an insulation failure between the contact point and the grounding part, a configuration is adopted that avoids a situation where the insulation inspection apparatus 1 is damaged.

具体的には、制御部８は、スイッチ７に対して制御信号Ｓ２を出力して抵抗４ｂを測定部３に接続させると共に、電源部２に対して制御信号Ｓ３を出力して、一例として、１０００Ｖの直流電圧を出力させる。次いで、制御部８は、測定部３に対して制御信号Ｓ４を出力して、出力端子５０ａと接地部位との間を流れる電流の電流値（「第４の電流値」の一例）を測定させる。また、制御部８は、測定部３から出力される測定値データＤ１に基づき、測定部３によって測定された電流値が予め規定された基準電流値（一例として、１．０ｍＡ）を下回っているか否かを判別する。この際に、測定された電流値が基準電流値以上のときには、太陽光発電ユニット５０に絶縁不良が生じている（抵抗成分Ｒａまたは抵抗成分Ｒｂが明らかに絶縁不良と判別するための基準となる基準抵抗値よりも小さい）と判別して、その旨を図示しない表示部に表示させて、一連の検査処理を終了する。 Specifically, the control unit 8 outputs a control signal S2 to the switch 7 to connect the resistor 4b to the measurement unit 3, and outputs a control signal S3 to the power supply unit 2. A DC voltage of 1000 V is output. Next, the control unit 8 outputs a control signal S4 to the measurement unit 3 to measure the current value of the current flowing between the output terminal 50a and the ground portion (an example of “fourth current value”). . Moreover, the control part 8 is based on the measurement value data D1 output from the measurement part 3, and the electric current value measured by the measurement part 3 is less than the standard electric current value (1.0 mA as an example) prescribed | regulated previously. Determine whether or not. At this time, if the measured current value is equal to or greater than the reference current value, an insulation failure has occurred in the photovoltaic power generation unit 50 (the resistance component Ra or the resistance component Rb is clearly a reference for determining an insulation failure). (It is smaller than the reference resistance value), the fact is displayed on a display unit (not shown), and the series of inspection processes is completed.

一方、測定された電流値が基準電流値を下回っているときには、制御部８は、出力端子５０ａと接地部位との間の絶縁抵抗値を測定する処理に移行する。具体的には、制御部８は、スイッチ７に対して制御信号Ｓ２を出力して、抵抗４ｂに代えて、抵抗値が小さい抵抗４ａ（この例では、１ｋΩ）を測定部３に接続させる。次いで、制御部８は、電源部２に対して制御信号Ｓ３を出力して、一例として、１０００Ｖの直流電圧を出力させると共に、測定部３に対して制御信号Ｓ４を出力して、出力端子５０ａと接地部位との間を流れる電流の電流値を測定させて、測定部３から出力される測定値データＤ１を記憶部９に記憶させる。 On the other hand, when the measured current value is lower than the reference current value, the control unit 8 shifts to a process of measuring the insulation resistance value between the output terminal 50a and the ground portion. Specifically, the control unit 8 outputs the control signal S2 to the switch 7 and connects the resistance 4a (1 kΩ in this example) having a small resistance value to the measurement unit 3 instead of the resistance 4b. Next, the control unit 8 outputs a control signal S3 to the power supply unit 2 to output a DC voltage of 1000 V as an example, and also outputs a control signal S4 to the measurement unit 3, and outputs the output terminal 50a. The measured value data D1 output from the measurement unit 3 is stored in the storage unit 9 by measuring the current value of the current flowing between the contact point and the grounded part.

続いて、制御部８は、電源部２に対して制御信号Ｓ３を出力して、一例として、７５０Ｖの直流電圧を出力させると共に（「一方の出力端子と接地部位との間に印加する検査用電圧の電圧値を変更させる」との処理の一例）、測定部３に対して制御信号Ｓ４を出力して、出力端子５０ａと接地部位との間を流れる電流の電流値を測定させて、測定部３から出力される測定値データＤ１を記憶部９に記憶させる。同様にして、制御部８は、電源部２に対して、５００Ｖの直流電圧を印加させた状態、および２５０Ｖの直流電圧を印加させた状態において測定部３に対して電流値をそれぞれ測定させて、測定部３から出力される測定値データＤ１を記憶部９に順次記憶させる。 Subsequently, the control unit 8 outputs a control signal S3 to the power supply unit 2 to output a DC voltage of 750 V as an example (“inspection applied between one output terminal and a grounded part” An example of the process of “changing the voltage value of the voltage”), the control signal S4 is output to the measuring unit 3, and the current value of the current flowing between the output terminal 50a and the grounding part is measured to measure. The measured value data D1 output from the unit 3 is stored in the storage unit 9. Similarly, the control unit 8 causes the measurement unit 3 to measure the current value in a state where a DC voltage of 500 V is applied to the power source unit 2 and a DC voltage of 250 V is applied. Then, the measurement value data D1 output from the measurement unit 3 is sequentially stored in the storage unit 9.

この場合、検査対象の太陽光発電ユニット５０が正常に絶縁された状態で設置されていたとしても、出力端子５０ａと接地部位との間、または、出力端子５０ｂと接地部位との間に大きな抵抗値の抵抗成分Ｒａ、または、大きな抵抗値の抵抗成分Ｒｂが存在した状態となる。この状態では、太陽光発電ユニット５０の各太陽電池モジュールに対して太陽光が照射されて、出力端子５０ａと接地部位との間に３００Ｖ程度の電位差が生じた状態においては、電源部２から検査用の電圧を印加していない状態であっても、０．３ｍＡ程度の漏れ電流が測定される。したがって、制御部８は、電源部２に対して制御信号Ｓ３を出力して、電圧の印加を停止させると共に（「一方の出力端子と接地部位との間に対する検査用電圧の印加を停止させた状態」の一例）、測定部３に対して制御信号Ｓ４を出力して、出力端子５０ａと接地部位との間を流れる電流の電流値（「第２の電流値」の一例）を測定させて、測定部３から出力される測定値データＤ１を記憶部９に記憶させる。 In this case, even if the photovoltaic power generation unit 50 to be inspected is installed in a normally insulated state, a large resistance is provided between the output terminal 50a and the ground part or between the output terminal 50b and the ground part. The resistance component Ra having a large value or the resistance component Rb having a large resistance value is present. In this state, when the solar cell module of the photovoltaic power generation unit 50 is irradiated with sunlight, and a potential difference of about 300 V is generated between the output terminal 50a and the grounded portion, the power supply unit 2 inspects the solar cell module. Even in the state where no voltage is applied, a leakage current of about 0.3 mA is measured. Therefore, the control unit 8 outputs the control signal S3 to the power supply unit 2 to stop the application of the voltage (“the application of the inspection voltage between the one output terminal and the ground portion is stopped). An example of “state”), the control signal S4 is output to the measurement unit 3, and the current value of the current flowing between the output terminal 50a and the grounding part (an example of “second current value”) is measured. The measurement value data D1 output from the measurement unit 3 is stored in the storage unit 9.

一方、出力端子５０ａと接地部位との間に検査用電圧を印加した状態において測定される電流値は、印加した検査用電圧の電圧値に対して直線比例しないことがある。したがって、制御部８は、各検査用電圧値を印加した状態において測定された各電流値（記憶部９に記憶させた各測定値データＤ１）と、印加した検査用電圧の電圧値（この例では、１０００Ｖ、７５０Ｖ、５００Ｖおよび２５０Ｖ）とに基づいて、出力端子５０ａと接地部位との間を流れる電流値を直線近似する直線近似処理を実行する。次いで、制御部８は、処理結果に基づき、一例として、１０００Ｖを印加した際に出力端子５０ａと接地部位との間を流れる電流の電流値（「第１の電流値」の一例：一例として、１．３ｍＡ）を演算する（「直線近似処理して第１の電流値を取得する」との処理の一例）。 On the other hand, the current value measured in a state where the inspection voltage is applied between the output terminal 50a and the ground part may not be linearly proportional to the voltage value of the applied inspection voltage. Accordingly, the control unit 8 determines each current value (each measured value data D1 stored in the storage unit 9) measured in a state where each test voltage value is applied and the voltage value of the applied test voltage (this example). Then, based on 1000V, 750V, 500V, and 250V), a linear approximation process for linearly approximating the value of the current flowing between the output terminal 50a and the grounded portion is executed. Next, based on the processing result, the control unit 8, as an example, the current value of the current flowing between the output terminal 50 a and the ground portion when 1000 V is applied (an example of the “first current value”: 1.3 mA) (an example of a process of “acquiring a first current value by performing a linear approximation process”).

次いで、制御部８は、演算した電流値から、検査用電圧の印加を停止した状態において測定された上記の漏れ電流の電流値を差し引く。これにより、太陽光発電ユニット５０による太陽光発電によって出力端子５０ａと接地部位との間に生じた上記した３００Ｖ程度の電位差の影響を除外した電流値（「第３の電流値」の一例：一例として、１．０ｍＡ）が演算される。続いて、制御部８は、演算した電流値と、その電流値が測定されたときに電源部２によって印加した検査用電圧の電圧値（この例では、１０００Ｖ）とに基づき、出力端子５０ａと接地部位との間の抵抗成分Ｒａの抵抗値（太陽光発電ユニット５０の絶縁抵抗値）を演算する。これにより、出力端子５０ａと接地部位との間の絶縁抵抗値の測定処理が完了する。次いで、制御部８は、記憶部９に記憶されている基準値データＤ０に基づき、演算した抵抗値が基準値以上であるか否かを判別し、その判別結果を図示しない表示部に表示させる。 Next, the control unit 8 subtracts the current value of the leakage current measured in a state where the application of the inspection voltage is stopped from the calculated current value. Thereby, the current value excluding the effect of the above-described potential difference of about 300 V generated between the output terminal 50a and the grounded part by the photovoltaic power generation by the photovoltaic power generation unit 50 (an example of “third current value”: one example) Is calculated as 1.0 mA). Subsequently, the control unit 8 determines the output terminal 50a based on the calculated current value and the voltage value (1000 V in this example) of the test voltage applied by the power source unit 2 when the current value is measured. The resistance value of the resistance component Ra between the grounding part (insulation resistance value of the photovoltaic power generation unit 50) is calculated. Thereby, the measurement process of the insulation resistance value between the output terminal 50a and the grounded part is completed. Next, the control unit 8 determines whether or not the calculated resistance value is greater than or equal to the reference value based on the reference value data D0 stored in the storage unit 9, and displays the determination result on a display unit (not shown). .

続いて、制御部８は、スイッチ６に対して制御信号Ｓ１を出力することにより、接続端子５ｂ（出力端子５０ｂ）を電源部２に接続させ、出力端子５０ａと接地部位との間の一連の測定手順と同様の手順に従って電流値の測定処理を実行し、出力端子５０ｂと接地部位との間の抵抗成分Ｒｂの抵抗値（太陽光発電ユニット５０の絶縁抵抗値）を演算する。これにより、出力端子５０ｂと接地部位との間の絶縁抵抗値の測定処理が完了する。次いで、制御部８は、記憶部９に記憶されている基準値データＤ０に基づき、演算した抵抗値が基準値以上であるか否かを判別し、その判別結果を図示しない表示部に表示させる。 Subsequently, the control unit 8 outputs the control signal S1 to the switch 6 to connect the connection terminal 5b (output terminal 50b) to the power supply unit 2, and a series of the connection between the output terminal 50a and the grounded portion. A current value measurement process is executed according to the same procedure as the measurement procedure, and the resistance value of the resistance component Rb (insulation resistance value of the photovoltaic power generation unit 50) between the output terminal 50b and the ground portion is calculated. Thereby, the measurement process of the insulation resistance value between the output terminal 50b and the grounded part is completed. Next, the control unit 8 determines whether or not the calculated resistance value is greater than or equal to the reference value based on the reference value data D0 stored in the storage unit 9, and displays the determination result on a display unit (not shown). .

この場合、太陽光発電ユニット５０を構成する各太陽電池モジュールのいずれかに断線等の破損が生じている状態、または、各太陽電池モジュールが正常に接続されていない状態において、出力端子５０ｂと接地部位との間に絶縁不良が生じていたときには、前述した出力端子５０ａと接地部位との絶縁抵抗値は基準値以上となるものの、出力端子５０ｂと接地部位との絶縁抵抗値は基準値を下回ることとなる。したがって、制御部８は、出力端子５０ａと接地部位との間の絶縁抵抗値、および出力端子５０ｂと接地部位との間の絶縁抵抗値のいずれかが基準値を下回っているときには、太陽光発電ユニット５０に絶縁不良が生じていると判別して、その検査結果を図示しない表示部に表示させて、一連の検査処理を終了する。 In this case, the output terminal 50b is grounded in a state where breakage such as disconnection occurs in any of the solar cell modules constituting the solar power generation unit 50, or in a state where the solar cell modules are not normally connected. When an insulation failure occurs between the output terminal 50a and the ground part, the insulation resistance value between the output terminal 50a and the ground part is equal to or higher than the reference value, but the insulation resistance value between the output terminal 50b and the ground part is lower than the reference value. It will be. Therefore, when either the insulation resistance value between the output terminal 50a and the ground part and the insulation resistance value between the output terminal 50b and the ground part are below the reference value, the control unit 8 It is determined that an insulation failure has occurred in the unit 50, the inspection result is displayed on a display unit (not shown), and the series of inspection processes is completed.

一方、太陽光発電ユニット５０を構成する各太陽電池モジュールに断線等の破損が生じておらず、かつ、各太陽電池モジュールが正常に接続されている状態において、出力端子５０ａと接地部位との間、および出力端子５０ｂと出力端子５０ａとの間に絶縁不良が生じていないときには、出力端子５０ａと接地部位との絶縁抵抗値、および出力端子５０ｂと接地部位との絶縁抵抗値の双方が基準値以上となる。したがって、制御部８は、出力端子５０ａと接地部位との間の絶縁抵抗値、および出力端子５０ｂと接地部位との間の絶縁抵抗値の双方が基準値以上のときに、太陽光発電ユニット５０の絶縁状態が良好であると判別して、その検査結果を図示しない表示部に表示させて、一連の検査処理を終了する。なお、太陽光発電ユニット５０を構成する各太陽電池モジュールに断線等の破損が生じているか否かの検査や、太陽光発電ユニット５０を構成する各太陽電池モジュールが正常に接続されているか否かの検査については、本例において説明した検査処理とは別個に検査される。 On the other hand, in the state where each solar cell module constituting the solar power generation unit 50 is not damaged such as disconnection and each solar cell module is normally connected, between the output terminal 50a and the grounding part. When the insulation failure does not occur between the output terminal 50b and the output terminal 50a, both the insulation resistance value between the output terminal 50a and the ground part and the insulation resistance value between the output terminal 50b and the ground part are reference values. That's it. Therefore, the control unit 8 determines that the photovoltaic power generation unit 50 when both the insulation resistance value between the output terminal 50a and the ground portion and the insulation resistance value between the output terminal 50b and the ground portion are equal to or greater than the reference value. It is determined that the insulation state is good, the inspection result is displayed on a display unit (not shown), and the series of inspection processes is completed. In addition, it is inspected whether each solar cell module constituting the solar power generation unit 50 is damaged such as disconnection, or whether each solar cell module constituting the solar power generation unit 50 is normally connected. This inspection is performed separately from the inspection process described in this example.

このように、この絶縁検査装置１、および絶縁検査装置１による絶縁抵抗測定方法によれば、出力端子５０ａ，５０ｂのいずれか一方（例えば、出力端子５０ａ）と接地部位との間に検査用電圧を印加した状態において出力端子５０ａと接地部位との間を流れる電流の第１の電流値を測定すると共に、出力端子５０ａと接地部位との間に対する検査用電圧の印加を停止した状態において出力端子５０ａと接地部位との間を流れる電流の第２の電流値を測定し、第１の電流値から第２の電流値を差し引いた第３の電流値と検査用電圧の電圧値とに基づいて出力端子５０ａと接地部位との間の絶縁抵抗値を演算することにより、出力端子５０ａ，５０ｂを短絡することなく絶縁抵抗を検査することができるため、出力端子５０ａ，５０ｂの間に大きな電位差が生じている状態（太陽光発電ユニット５０に太陽光が照射されている状態）であっても、測定作業を安全に実施することができる。また、「起電力を有する測定対象体」としての太陽光発電ユニット５０を測定対象とする場合においても、高所に設置されている太陽光発電ユニット５０を遮光布で覆う作業が不要となり、太陽光の照射を避けて夜間に測定作業を実施する必要もないことから、太陽光発電ユニット５０の絶縁抵抗値を安全かつ簡便に測定することができる。また、出力端子５０ａ，５０ｂの間に生じた電位差に起因する電流の電流値を差し引いているため、太陽光発電ユニット５０の絶縁抵抗値を正確に測定することができる。 As described above, according to the insulation inspection device 1 and the insulation resistance measuring method using the insulation inspection device 1, the inspection voltage is set between one of the output terminals 50a and 50b (for example, the output terminal 50a) and the ground portion. The first current value of the current flowing between the output terminal 50a and the grounded part is measured in the state where the voltage is applied, and the output terminal is stopped in the state where the application of the inspection voltage to the output terminal 50a and the grounded part is stopped. Based on the third current value obtained by subtracting the second current value from the first current value and the voltage value of the test voltage, the second current value of the current flowing between 50a and the grounding part is measured. By calculating the insulation resistance value between the output terminal 50a and the ground portion, the insulation resistance can be inspected without short-circuiting the output terminals 50a and 50b. Even if the such a potential difference is generated (state photovoltaic solar power unit 50 is irradiated), it is possible to safely implement the measurement operation. In addition, even when the photovoltaic power generation unit 50 as the “measurement object having an electromotive force” is the measurement target, it is not necessary to cover the photovoltaic power generation unit 50 installed at a high place with a light shielding cloth. Since it is not necessary to carry out measurement work at night by avoiding light irradiation, the insulation resistance value of the photovoltaic power generation unit 50 can be measured safely and easily. Further, since the current value of the current due to the potential difference generated between the output terminals 50a and 50b is subtracted, the insulation resistance value of the photovoltaic power generation unit 50 can be accurately measured.

また、この絶縁検査装置１、および絶縁検査装置１による絶縁抵抗測定方法によれば、出力端子５０ａ，５０ｂのいずれか一方（例えば、出力端子５０ａ）の出力端子と接地部位との間に印加する検査用電圧の電圧値を変更しつつ、変更した各検査用電圧を印加した状態において出力端子５０ａと接地部位との間に流れる各電流値をそれぞれ測定すると共に、変更した各電圧値と測定した各電流値とに基づいて出力端子５０ａと接地部位との間を流れる電流値を直線近似処理して上記の第１の電流値を取得することにより、いずれか１つの電圧値の検査用電圧を印加して測定した電流値に基づいて絶縁抵抗値を演算する方法および構成と比較して、太陽光発電ユニット５０の絶縁抵抗値を一層正確に測定することができる。 In addition, according to the insulation inspection device 1 and the insulation resistance measurement method using the insulation inspection device 1, it is applied between the output terminal of one of the output terminals 50a and 50b (for example, the output terminal 50a) and the ground portion. While changing the voltage value of the inspection voltage, each current value flowing between the output terminal 50a and the grounded part was measured in a state where each changed inspection voltage was applied, and each changed voltage value was measured. Based on each current value, the current value flowing between the output terminal 50a and the grounding part is linearly approximated to obtain the first current value, thereby obtaining a test voltage of any one voltage value. Compared with the method and configuration for calculating the insulation resistance value based on the measured current value, the insulation resistance value of the photovoltaic power generation unit 50 can be measured more accurately.

さらに、この絶縁検査装置１、および絶縁検査装置１による太陽光発電ユニット５０の検査方法によれば、上記の絶縁抵抗測定方法に従い、出力端子５０ａと接地部位との間の絶縁抵抗値、および出力端子５０ｂと接地部位との間の絶縁抵抗値をそれぞれ測定し、測定した両絶縁抵抗値が予め規定した基準値を超えているときに太陽光発電ユニット５０の接地部位との間の絶縁状態を良好と検査することにより、太陽光発電ユニット５０を構成する各太陽電池モジュールのいずれかに断線が生じていたり、各太陽電池モジュールに接続不良が生じていたとしても、太陽光発電ユニット５０の各部（出力端子５０ａの側、および出力端子５０ｂの側）における絶縁状態の良否を確実に検査することができる。 Further, according to the insulation inspection apparatus 1 and the inspection method of the photovoltaic power generation unit 50 by the insulation inspection apparatus 1, according to the insulation resistance measurement method, the insulation resistance value between the output terminal 50a and the ground part, and the output The insulation resistance value between the terminal 50b and the ground part is measured, and the insulation state between the ground part of the photovoltaic power generation unit 50 is measured when both measured insulation resistance values exceed a predetermined reference value. Even if a disconnection has occurred in any of the solar cell modules constituting the solar power generation unit 50 or a connection failure has occurred in each solar cell module by checking that it is good, each part of the solar power generation unit 50 The quality of the insulation state on the output terminal 50a side and the output terminal 50b side can be reliably inspected.

また、この絶縁検査装置１、および絶縁検査装置１による絶縁抵抗測定方法によれば、抵抗４ａよりも大きな抵抗値の抵抗４ｂを接続すると共に出力端子５０ａ，５０ｂのいずれか一方（例えば、出力端子５０ａ）と接地部位との間に検査用電圧を印加した状態において測定した電流の第４の電流値が予め規定された基準電流値を下回っているときに、抵抗値が小さい抵抗４ａを接続した状態において測定した第１の電流値に基づいて絶縁抵抗値を演算することにより、太陽光発電ユニット５０に絶縁不良が生じていたとしても、太陽光発電ユニット５０の出力端子５０ａ，５０ｂと接地部位との間に生じている電位差（太陽光発電ユニット５０の起電力）に起因して大きな電流が流れることがないため、絶縁検査装置１が破損する事態を回避することができるだけでなく、絶縁抵抗値の測定に際しては、抵抗値が小さい抵抗４ａを接続した状態において電流値を測定できるため、太陽光発電ユニット５０の絶縁抵抗値を正確に測定することができる。 Further, according to the insulation inspection device 1 and the insulation resistance measuring method using the insulation inspection device 1, the resistor 4b having a resistance value larger than that of the resistor 4a is connected and either one of the output terminals 50a and 50b (for example, the output terminal) When the fourth current value of the current measured in the state where the test voltage is applied is less than the predetermined reference current value, the resistor 4a having a small resistance value is connected. Even if an insulation failure occurs in the photovoltaic power generation unit 50 by calculating the insulation resistance value based on the first current value measured in the state, the output terminals 50a and 50b and the grounding part of the photovoltaic power generation unit 50 Since a large current does not flow due to the potential difference (electromotive force of the photovoltaic power generation unit 50) generated between the insulation inspection device 1 and the insulation inspection device 1 is damaged. In addition, when measuring the insulation resistance value, the current value can be measured with the resistor 4a having a small resistance value connected, so that the insulation resistance value of the photovoltaic power generation unit 50 can be accurately measured. .

なお、検査用電圧の電圧値を多段階に変化させることが可能な電圧値可変型の直流電圧源（図示せず）を備えた電源部２によって検査用電圧の電圧値を変更して印加しつつ、出力端子５０ａ，５０ｂと接地部位との間を流れる電流の電流値を測定した後に、印加した検査用電圧の電圧値と、測定した各電流値とに基づいて、出力端子５０ａ，５０ｂと接地部位との間を流れる電流の電流値を直線近似処理する方法および構成について説明したが、上記の直線近似処理は、絶縁抵抗測定方法（絶縁抵抗測定装置）において必須の処理ではない。つまり、検査用電圧が印加されている状態において測定された電流値から、検査用電圧の印加が停止された状態において測定された電流値を差し引いた電流値に基づいて絶縁抵抗値を測定することができる。 Note that the voltage value of the inspection voltage is changed and applied by the power supply unit 2 having a voltage value variable type DC voltage source (not shown) capable of changing the voltage value of the inspection voltage in multiple stages. On the other hand, after measuring the current value of the current flowing between the output terminals 50a and 50b and the grounded part, the output terminals 50a and 50b are determined based on the voltage value of the applied inspection voltage and the measured current values. Although the method and configuration for linearly approximating the current value of the current flowing between the grounded portion and the configuration have been described, the above linear approximation processing is not an essential process in the insulation resistance measurement method (insulation resistance measurement device). That is, the insulation resistance value is measured based on a current value obtained by subtracting a current value measured in a state where the application of the inspection voltage is stopped from a current value measured in a state where the inspection voltage is applied. Can do.

直線近似処理が不要なときには、上記の絶縁検査装置１における電源部２に代えて、図２に示す電源部２ａによって検査用電圧を印加したり、検査用電圧の印加を停止したりする方法および構成を採用することもできる。なお、この電源部２ａを備えた絶縁検査装置における電源部２ａを除く構成要素については、前述した絶縁検査装置１と同様のため、図示および詳細な説明を省略する。この場合、電源部２ａは、電圧値固定型の直流電圧源１１と、スイッチ１２，１３とを備えて構成されている。この電源部２ａを備えた絶縁検査装置によって絶縁抵抗値を測定する際には、スイッチ１２，１３の接続状態を適宜切り替えることにより、「一方の接続端子と接地部位との間に検査用電圧を印加した状態（各スイッチ１２，１３が同図に示す切り替え状態）」および「一方の接続端子と接地部位との間に対する検査用電圧の印加を停止した状態（各スイッチ１２，１３を同図に示す切り替え状態から共に切り替えた状態）」のいずれかに切り替えることができる。 When the straight line approximation process is unnecessary, a method of applying a test voltage or stopping the application of the test voltage by the power supply unit 2a shown in FIG. 2 instead of the power supply unit 2 in the insulation test apparatus 1 A configuration can also be adopted. In addition, since components other than the power supply unit 2a in the insulation inspection apparatus provided with the power supply unit 2a are the same as those of the above-described insulation inspection apparatus 1, illustration and detailed description thereof are omitted. In this case, the power supply unit 2 a includes a fixed voltage value type DC voltage source 11 and switches 12 and 13. When measuring the insulation resistance value with the insulation inspection device provided with the power supply unit 2a, by appropriately switching the connection state of the switches 12 and 13, "a voltage for inspection is applied between one connection terminal and the ground part". Applied state (switches 12 and 13 are switched as shown in the figure) "and" A test voltage application between one connection terminal and the grounded part is stopped (switches 12 and 13 are shown in the figure). From the switching state shown to the state where both are switched).

また、出力端子５０ａと接地部位との間の絶縁抵抗値、および出力端子５０ｂと接地部位との間の絶縁抵抗値の双方を測定する例について説明したが、前述したように、太陽光発電ユニット５０を構成する各太陽電池モジュールに断線等の破損が生じておらず、かつ、各太陽電池モジュールが正常に接続されている状態においては、出力端子５０ａと接地部位との間の絶縁抵抗値、および出力端子５０ｂと接地部位との間の絶縁抵抗値としてほぼ同じ抵抗値が測定される。したがって、出力端子５０ａ，５０ｂのいずれか一方と接地部位との間の絶縁抵抗値だけを測定する方法および構成を採用することもできる。このような方法および構成を採用した場合においても、両出力端子５０ａ，５０ｂを短絡する作業が不要となる結果、任意の時点において絶縁抵抗値を安全かつ簡便に測定することができる。 Moreover, although the example which measures both the insulation resistance value between the output terminal 50a and a grounding part and the insulation resistance value between the output terminal 50b and a grounding part was demonstrated, as mentioned above, a photovoltaic power generation unit In the state where breakage or the like has not occurred in each solar cell module constituting 50 and each solar cell module is normally connected, the insulation resistance value between the output terminal 50a and the grounding part, In addition, almost the same resistance value is measured as the insulation resistance value between the output terminal 50b and the grounded portion. Therefore, it is possible to employ a method and configuration for measuring only the insulation resistance value between either one of the output terminals 50a and 50b and the ground portion. Even when such a method and configuration are employed, it is not necessary to short-circuit both output terminals 50a and 50b. As a result, the insulation resistance value can be measured safely and simply at an arbitrary time.

さらに、太陽光発電ユニット５０の出力端子５０ａ，５０ｂに対して接続端子５ａ，５ｂを接続した状態において、スイッチ６による接続の切替えによって、出力端子５０ａ，５０ｂのいずれかを電源部２に対して接続する方法および構成について説明したが、スイッチ６を設けずに、接続端子５ａ，５ｂのいずれか一方（例えば、接続端子５ａ）を電源部２に対して直接的に接続しておき、出力端子５０ａと接地部位との間の絶縁抵抗値を測定する際には、接続端子５ａを出力端子５０ａに接続し、出力端子５０ｂと接地部位との間の絶縁抵抗値を測定する際には、接続端子５ａを出力端子５０ｂに接続して絶縁抵抗値の測定および検査を行う方法および構成を採用することもできる。このような方法および構成を採用した場合においても、両出力端子５０ａ，５０ｂを短絡する作業が不要となる結果、任意の時点において絶縁抵抗値を安全かつ簡便に測定することができる。 Further, in a state where the connection terminals 5 a and 5 b are connected to the output terminals 50 a and 50 b of the photovoltaic power generation unit 50, any one of the output terminals 50 a and 50 b is connected to the power supply unit 2 by switching the connection by the switch 6. Although the connection method and configuration have been described, either one of the connection terminals 5a and 5b (for example, the connection terminal 5a) is directly connected to the power supply unit 2 without providing the switch 6, and the output terminal When measuring the insulation resistance value between 50a and the grounded part, the connection terminal 5a is connected to the output terminal 50a, and when measuring the insulation resistance value between the output terminal 50b and the grounded part, the connection is made. It is also possible to employ a method and configuration for measuring and inspecting the insulation resistance value by connecting the terminal 5a to the output terminal 50b. Even when such a method and configuration are employed, it is not necessary to short-circuit both output terminals 50a and 50b. As a result, the insulation resistance value can be measured safely and simply at an arbitrary time.

また、電源部２が制御部８からの制御信号Ｓ３に基づいて検査用電圧を印加したり印加を停止する構成の絶縁検査装置１を例に挙げて説明したが、検査用電圧の印加や印加の停止を手動で切り替える構成を採用することもできる。さらに、測定部３が制御部８からの制御信号Ｓ４に応じて電流値の測定処理を開始する構成の絶縁検査装置１を例に挙げて説明したが、測定部３による電流値の測定処理を手動で開始させる構成を採用することもできる。加えて、「起電力を有する測定対象体」の一例として、複数の太陽電池モジュールを備えた太陽光発電ユニット５０の絶縁抵抗値を測定する例について説明したが、測定対象体は、太陽光発電ユニット（太陽電池モジュール）に限定されず、風力発電ユニットや、水力発電ユニット、潮力発電ユニットおよび地熱発電ユニット等の各種の「起電力を有する物」がこれに含まれる。 Further, although the power supply unit 2 has been described by taking the example of the insulation inspection apparatus 1 configured to apply or stop applying the inspection voltage based on the control signal S3 from the control unit 8, the application or application of the inspection voltage is described. It is also possible to adopt a configuration in which the stoppage is manually switched. Furthermore, although the measurement unit 3 has been described by taking the example of the insulation inspection apparatus 1 configured to start the current value measurement process in response to the control signal S4 from the control unit 8, the current value measurement process by the measurement unit 3 is described. It is also possible to adopt a configuration that starts manually. In addition, as an example of the “measurement object having an electromotive force”, an example in which the insulation resistance value of the photovoltaic power generation unit 50 including a plurality of solar cell modules is measured has been described. It is not limited to a unit (solar cell module), but includes various “things having electromotive force” such as a wind power generation unit, a hydroelectric power generation unit, a tidal power generation unit, and a geothermal power generation unit.

１絶縁検査装置
２，２ａ電源部
３測定部
４ａ，４ｂ抵抗
５ａ〜５ｃ接続端子
６，７，１２，１３スイッチ
８制御部
９記憶部
１１直流電圧源
５０太陽光発電ユニット
５０ａ，５０ｂ出力端子
Ｄ０基準値データ
Ｄ１測定値データ
Ｒａ，Ｒｂ抵抗成分
Ｓ１〜Ｓ４制御信号 DESCRIPTION OF SYMBOLS 1 Insulation inspection apparatus 2, 2a Power supply part 3 Measuring part 4a, 4b Resistance 5a-5c Connection terminal 6, 7, 12, 13 Switch 8 Control part 9 Memory | storage part 11 DC voltage source 50 Solar power generation unit 50a, 50b Output terminal D0 Reference value data D1 Measured value data Ra, Rb Resistance component S1-S4 Control signal

Claims

A first current flowing between the one output terminal and the grounded part in a state where a test voltage is applied between any one of the pair of output terminals and the grounded part in the measurement object having an electromotive force. While measuring the current value, the second current flowing between the one output terminal and the grounding part in a state where the application of the inspection voltage between the one output terminal and the grounding part is stopped. A current value is measured, and based on the third current value obtained by subtracting the second current value from the first current value and the voltage value of the test voltage, the one output terminal and the grounding portion The insulation resistance value between each of the pair of output terminals and the grounding part is calculated according to an insulation resistance measurement method for calculating the insulation resistance value between them, and the calculated both insulation resistance values are reference values defined in advance. Beyond Inspection method for inspecting a good insulation state between the ground portion of the measured object when.

While changing the voltage value of the inspection voltage applied between the one output terminal and the grounding portion, the one output terminal and the grounding portion in a state where the changed inspection voltages are applied. And each of the current values flowing between the one output terminal and the grounded portion is linearly approximated based on the changed voltage values and the measured current values. The inspection method according to claim 1, wherein the first current value is obtained by processing.

Of the first resistor and the second resistor having a larger resistance value than the first resistor, the second resistor is connected between the one output terminal and the ground portion, and the inspection voltage is set. When the fourth current value of the current flowing between the one output terminal and the grounding portion measured in the applied state is lower than a predetermined reference current value, the second resistor is replaced. The insulation resistance value is calculated based on the measured first current value in a state where the first resistance is connected between the one output terminal and the ground portion and the inspection voltage is applied. The inspection method according to claim 1 or 2 .

A power supply unit that applies a test voltage between one of a pair of output terminals and a grounding part in a measurement object having an electromotive force, and a current value of a current that flows between the one output terminal and the grounding part And the one output terminal based on the current value measured by the measurement unit and the voltage value of the inspection voltage in a state where the inspection voltage is applied by the power source unit. A control unit that calculates an insulation resistance value between the grounding part,
The control unit, from the first current value of the current flowing between the one output terminal and the ground portion measured by the measurement unit in a state where the inspection voltage is applied by the power supply unit, A third current value obtained by subtracting a second current value of a current flowing between the one output terminal measured by the measurement unit and the grounding part in a state where application of the inspection voltage is stopped; between each and the ground portion of the pair of output terminals in accordance with the insulation resistance measuring method for calculating the insulation resistance value between the one output terminal and the ground site the based on the voltage value of the test voltage An inspection apparatus that calculates the insulation resistance value and inspects that the insulation state between the measurement object and the grounding part is good when both the calculated insulation resistance values exceed a predetermined reference value.

The power supply unit is configured to be able to change the voltage value of the inspection voltage,
The control unit controls the power supply unit to change the voltage value of the inspection voltage to be applied between the one output terminal and the ground part, and applies the changed inspection voltages. In accordance with each of the current values flowing between the one output terminal and the grounding portion respectively measured by the measurement unit and each voltage value of the applied inspection voltage. The inspection apparatus according to claim 4, wherein the first current value is obtained by performing a linear approximation process on a current value flowing between the output terminal and the ground portion.

Any one of the first resistor, the second resistor having a larger resistance value than the first resistor, and the first resistor and the second resistor is provided between the one output terminal and the grounding portion. It has a connection switching part that connects to
The control unit controls the connection switching unit to connect the second resistor and the one output terminal measured by the measurement unit in a state where the inspection voltage is applied by the power source unit. When the fourth current value of the current flowing between the grounding part is lower than a predetermined reference current value, the connection switching unit is controlled to connect the first resistor and for the inspection The inspection apparatus according to claim 4, wherein the insulation resistance value is calculated based on the first current value measured by the measurement unit in a state where a voltage is applied.