JP2000023368A - Solar light power generation system - Google Patents

Solar light power generation system

Info

Publication number
JP2000023368A
JP2000023368A JP10185106A JP18510698A JP2000023368A JP 2000023368 A JP2000023368 A JP 2000023368A JP 10185106 A JP10185106 A JP 10185106A JP 18510698 A JP18510698 A JP 18510698A JP 2000023368 A JP2000023368 A JP 2000023368A
Authority
JP
Japan
Prior art keywords
power supply
ground fault
distributed power
inverter circuit
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP10185106A
Other languages
Japanese (ja)
Other versions
JP3533090B2 (en
Inventor
Kiyoshi Goto
潔 後藤
Yoichi Kunimoto
洋一 国本
Hiroaki Koshin
博昭 小新
Chukichi Mukai
忠吉 向井
Hirotada Higashihama
弘忠 東浜
Hiroaki Yuasa
裕明 湯浅
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Electric Works Co Ltd
Original Assignee
Matsushita Electric Works Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Works Ltd filed Critical Matsushita Electric Works Ltd
Priority to JP18510698A priority Critical patent/JP3533090B2/en
Publication of JP2000023368A publication Critical patent/JP2000023368A/en
Application granted granted Critical
Publication of JP3533090B2 publication Critical patent/JP3533090B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/50Photovoltaic [PV] energy
    • Y02E10/56Power conversion systems, e.g. maximum power point trackers

Abstract

PROBLEM TO BE SOLVED: To provide a solar light power generation system which has a master breaker at the commercial power supply side never which will not be cut off, even if there is a ground in a distributed power supply. SOLUTION: A distributed power supply is provided with an inverter circuit 6, which converts DC voltage output from a solar battery 1 into an AC voltage. A master breaker 20 constituted of ground leakage breakers is inserted between a commercial power supply 3 and a main line. Between the distributed power supply and the main line, a parallel-off switch 10 is inserted for system linkage/ system separation between the distributed power supply and the commercial power supply 3. When ground is detected between the solar battery 1 and the inverter circuit 6 by a current sensor 11 and a deciding circuit 9, a control section 8 stops the operation of the inverter circuit 6 after parallelling off the parallel-off switch 10.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、太陽電池を用いて
発電する分散電源と商用電源との系統連系を行なうよう
にした太陽光発電システムに関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic power generation system in which a distributed power supply that generates power using a solar cell and a commercial power supply are interconnected.

【0002】[0002]

【従来の技術】近年、太陽電池からなる直流電源を用い
インバータ回路により交流電力に電力変換する分散電源
を商用電源に系統連系し、負荷に交流電力を供給するよ
うにした太陽光発電システムが各種提案されている。
2. Description of the Related Art In recent years, there has been developed a solar power generation system in which a distributed power supply that converts power into AC power by an inverter circuit using a DC power supply composed of a solar cell is system-connected to a commercial power supply and supplies AC power to a load. Various proposals have been made.

【0003】この種の太陽光発電システムは、たとえば
図5に示すように、単相3線の商用電源3に漏電ブレー
カよりなる主幹ブレーカ20を介して接続した幹線と分
散電源との間に解列開閉器10を介在させてある。負荷
4には幹線を通して電力が供給され、負荷4に対して商
用電源3と分散電源とのどちらからも電力が供給可能に
なっている。分岐ブレーカなどは図では省略している。
分散電源は、多数の太陽電池セルを配列してパネル状と
した太陽電池1を備え、太陽電池1から出力される直流
電圧を昇圧チョッパ回路よりなる昇圧回路5により昇圧
し、昇圧回路5の出力電圧をインバータ回路6により交
流電圧に電力変換するように構成されている。インバー
タ回路6の出力はフィルタ回路7を通して解列開閉器1
0に接続される。このフィルタ回路7によりインバータ
回路6から出力されるパルス列が正弦波状に波形整形さ
れる。昇圧回路5およびインバータ回路6は、それぞれ
スイッチング素子52,61〜64を備え、これらのス
イッチング素子52,61〜64は制御部8により制御
される。ここに、スイッチング素子52,61〜64に
はIGBTを用いている。
As shown in FIG. 5, for example, this type of photovoltaic power generation system has a single-phase three-wire commercial power supply 3 connected between a mains connected to a single-phase three-wire commercial power supply 3 via a mains breaker 20 composed of an earth leakage breaker and a distributed power supply. The row switch 10 is interposed. Power is supplied to the load 4 through a main line, and power can be supplied to the load 4 from both the commercial power supply 3 and the distributed power supply. Branch breakers and the like are omitted in the figure.
The distributed power supply includes a solar cell 1 in which a large number of solar cells are arranged in a panel shape, and a DC voltage output from the solar cell 1 is boosted by a boosting circuit 5 including a boosting chopper circuit. The voltage is converted into an AC voltage by the inverter circuit 6. The output of the inverter circuit 6 passes through the filter circuit 7 and the parallel-off switch 1
Connected to 0. The pulse train output from the inverter circuit 6 is shaped into a sine wave by the filter circuit 7. The booster circuit 5 and the inverter circuit 6 include switching elements 52, 61 to 64, respectively, and these switching elements 52, 61 to 64 are controlled by the control unit 8. Here, IGBT is used for the switching elements 52, 61 to 64.

【0004】ところで、制御部8は各種の異常が検出さ
れたときに、スイッチング素子61〜64をオフにして
インバータ回路6の動作を停止させるとともに解列開閉
器10を解列させる機能を有している。つまり、異常時
には分散電源の動作を停止させて商用電源3に影響を与
えないようにする。このような異常の一つには地絡があ
り、商用電源3側の地絡は主幹ブレーカ20で検出され
るが、分散電源での地絡は主幹ブレーカ20では検出す
ることができないから、分散電源には、地絡検出用の電
流センサ11を設けてある。電流センサ11の出力は判
断回路9に与えられ、判断回路9は電流センサ11の出
力に基づいて地絡を検出すると、スイッチング素子61
〜64の動作を停止させかつ解列開閉器10を解列させ
るように制御部8を制御する。つまり、電流センサ11
および判断回路9により地絡検出手段が構成される。電
流センサ11としてはトロイダル状のコアを備える変流
器を用いている。
The control unit 8 has a function of turning off the switching elements 61 to 64 to stop the operation of the inverter circuit 6 and to disconnect the disconnection switch 10 when various abnormalities are detected. ing. That is, in the event of an abnormality, the operation of the distributed power supply is stopped so that the commercial power supply 3 is not affected. One of such abnormalities is a ground fault. The ground fault on the commercial power source 3 side is detected by the main breaker 20, but the ground fault at the distributed power source cannot be detected by the main breaker 20, so that the ground fault is not detected. The power supply is provided with a current sensor 11 for detecting a ground fault. The output of the current sensor 11 is provided to a determination circuit 9. When the determination circuit 9 detects a ground fault based on the output of the current sensor 11, the switching element 61
The control unit 8 is controlled so as to stop the operations of Nos. To 64 and to disconnect the disconnection switch 10. That is, the current sensor 11
And the judgment circuit 9 constitute a ground fault detecting means. As the current sensor 11, a current transformer having a toroidal core is used.

【0005】たとえば、太陽電池の負側で地絡が生じて
図5に抵抗Rgで示す経路が形成されると、太陽電池1
−昇圧回路5−インバータ回路6−フィルタ回路7−解
列開閉器10−主幹ブレーカ20−商用電源3−抵抗R
g−太陽電池1という経路を通して地絡電流Irが流れ
る。このように地絡電流Irが流れると電流センサ11
に流れる電流に不平衡が生じるから、電流センサ11の
出力に基づいて判断回路9が地絡と判断し、制御部8を
通してスイッチング素子61〜64をオフにし解列開閉
器10を解列させるのである。この種の技術は、たとえ
ば特開平9−285015号公報にも記載されている。
For example, when a ground fault occurs on the negative side of the solar cell to form a path indicated by a resistor Rg in FIG.
-Step-up circuit 5-Inverter circuit 6-Filter circuit 7-Off-line switch 10-Main breaker 20-Commercial power supply 3-Resistance R
A ground fault current Ir flows through a path of g-solar cell 1. When the ground fault current Ir flows in this manner, the current sensor 11
As a result, the determination circuit 9 determines that a ground fault has occurred based on the output of the current sensor 11 and turns off the switching elements 61 to 64 through the control unit 8 to disconnect the disconnecting switch 10. is there. This type of technique is also described in, for example, Japanese Patent Application Laid-Open No. 9-285015.

【0006】[0006]

【発明が解決しようとする課題】ところで、上述した太
陽光発電システムは、スイッチング素子61〜64をオ
フにしてインバータ回路6の動作を停止させる指示と、
解列開閉器10を解列させる指示とを制御部8から同時
に行なっている。しかしながら、制御部8からの指示に
対する応答時間は、スイッチング素子61〜64のほう
が解列開閉器10に比較すると圧倒的に短い。つまり、
図6に示すように、分散電源が正常に発電しているとき
に、分散電源において地絡電流Irが検出されて時刻t
aにおいて制御部8から停止の指令が発生したとする
と、インバータ回路6がただちに停止し、その後、時刻
tbになると解列開閉器10が解列(オフ)することに
なる。ここに、商用電源3は正常であるものとし、また
昇圧回路5はインバータ回路6が停止しても動作させて
おく。
By the way, in the above-mentioned photovoltaic power generation system, an instruction to turn off the switching elements 61 to 64 to stop the operation of the inverter circuit 6,
The instruction to disconnect the disconnection switch 10 is issued from the control unit 8 at the same time. However, the response time to the instruction from the control unit 8 is much shorter for the switching elements 61 to 64 than for the parallel-off switch 10. That is,
As shown in FIG. 6, when the distributed power supply is generating power normally, the distributed power supply detects the ground fault current Ir and the time t
Assuming that a stop command is issued from the control unit 8 at a, the inverter circuit 6 immediately stops, and thereafter, at time tb, the disconnecting switch 10 is disconnected (turned off). Here, the commercial power supply 3 is assumed to be normal, and the booster circuit 5 is operated even when the inverter circuit 6 is stopped.

【0007】上述のように系統連系運転中に地絡電流I
rが生じたときには、インバータ回路5の動作が停止し
た後に解列開閉器10が解列することになる。ここに、
インバータ回路6は、いわゆるフルブリッジ形のインバ
ータ回路であって、4個のスイッチング素子61〜64
からなるブリッジ回路を備え、また各スイッチング素子
61〜64にはそれぞれダイオード65〜68が逆並列
に接続される。たとえば、図示例でスイッチング素子5
2,61〜64に用いているIGBTは、インバータ用
として6個を1組とし、かつ各IGBTにそれぞれダイ
オード65〜68を逆並列に接続した形でパッケージに
収納した形で提供されているものを用いている。
As described above, the ground fault current I
When r occurs, the disconnecting switch 10 is disconnected after the operation of the inverter circuit 5 stops. here,
The inverter circuit 6 is a so-called full-bridge type inverter circuit, and includes four switching elements 61 to 64.
, And diodes 65 to 68 are connected in anti-parallel to the switching elements 61 to 64, respectively. For example, in the illustrated example, the switching element 5
The IGBTs used for 2,61 to 64 are provided in a form in which six IGBTs are used as a set for an inverter, and diodes 65 to 68 are connected in anti-parallel to each IGBT in a package. Is used.

【0008】しかして、インバータ回路6は商用電源3
に対して力率を1にするように制御されており、スイッ
チング素子61〜64がオンオフされている期間に分散
電源で地絡が生じてもスイッチング素子61〜64が商
用電源に同期してオンオフされるから、主幹ブレーカ2
0で分散電源の漏電が検出されることはない。しかしな
がら、解列開閉器10が解列する前にインバータ回路6
の動作が停止すると、地絡電流Irの流れる経路とし
て、図5に実線および破線で示すようなダイオード6
7,68を通る経路が生じ、この経路において地絡電流
Irは半波整流されて脈流状になる。つまり、図7に示
すように、時刻t1で地絡が発生し、時刻t2において
インバータ回路6のスイッチング素子61〜64が停止
したとしても、解列開閉器10が解列する時刻t3まで
に地絡電流が脈流状に流れる。図7における横軸の1目
盛は20m秒、縦軸の1目盛は50mAである。このよ
うな脈流状の電流が主幹ブレーカ20に流れると、主幹
ブレーカ20に流れる電流が不平衡になり、主幹ブレー
カ20で漏電が検出されて主幹ブレーカ20が遮断され
ることがある。要するに、分散電源において地絡が生じ
たにもかかわらず、商用電源3側に設けた主幹ブレーカ
10が遮断されて、商用電源3側には何の異常もない場
合でも負荷4に電力が供給されなくなるという問題が生
じる。また、分散電源での異常であるにもかかわらず商
用電源3側の主幹ブレーカ20が遮断されるから、商用
電源3と分散電源とのどちらで異常が生じているかがわ
かりにくく、復旧に時間がかかることになる。
However, the inverter circuit 6 is connected to the commercial power source 3
, The power factor is controlled to be 1 and the switching elements 61 to 64 are turned on and off in synchronization with the commercial power even if a ground fault occurs in the distributed power supply while the switching elements 61 to 64 are turned on and off. The main breaker 2
At 0, no leakage of the distributed power source is detected. However, before the disconnecting switch 10 is disconnected, the inverter circuit 6
Is stopped, a diode 6 as shown by a solid line and a broken line in FIG.
7 and 68, a ground fault current Ir is half-wave rectified in this path to form a pulsating flow. That is, as shown in FIG. 7, even if a ground fault occurs at time t1 and the switching elements 61 to 64 of the inverter circuit 6 stop at time t2, the ground fault occurs by time t3 when the disconnecting switch 10 is disconnected. A fault current flows in a pulsating flow. In FIG. 7, one scale on the horizontal axis is 20 ms, and one scale on the vertical axis is 50 mA. When such a pulsating current flows through the main breaker 20, the current flowing through the main breaker 20 becomes unbalanced, and the main breaker 20 may detect a leakage and shut off the main breaker 20. In short, despite the occurrence of a ground fault in the distributed power supply, the main breaker 10 provided on the commercial power supply 3 is shut off, and power is supplied to the load 4 even when there is no abnormality on the commercial power supply 3 side. The problem of disappearing occurs. Further, since the main breaker 20 on the commercial power supply 3 side is shut down despite the abnormality in the distributed power supply, it is difficult to know which of the commercial power supply 3 and the distributed power supply has failed, and it takes time to recover. That would be.

【0009】本発明は上記事由に鑑みて為されたもので
あり、その目的は、分散電源で地絡が生じても商用電源
側の主幹ブレーカが遮断されることのない太陽光発電シ
ステムを提供することにある。
The present invention has been made in view of the above circumstances, and an object thereof is to provide a photovoltaic power generation system in which a main circuit breaker on a commercial power supply side is not shut off even if a ground fault occurs in a distributed power supply. Is to do.

【0010】[0010]

【課題を解決するための手段】本発明は、太陽電池から
出力される直流電圧を交流電圧に電力変換するインバー
タ回路を備えた分散電源と、商用電源と幹線との間に接
続された漏電ブレーカよりなる主幹ブレーカと、分散電
源と幹線との間に挿入され分散電源と商用電源との系統
連系と系統分離とを行なう解列開閉器と、分散電源にお
ける地絡を検出する地絡検出手段と、地絡検出手段によ
り地絡が検出されると解列開閉器を解列した後にインバ
ータ回路の動作を停止させる制御部とを備えるものであ
る。
SUMMARY OF THE INVENTION The present invention provides a distributed power supply having an inverter circuit for converting a DC voltage output from a solar cell into an AC voltage, and an earth leakage breaker connected between a commercial power supply and a main line. A mains breaker, a disconnection switch inserted between the distributed power supply and the mains for system interconnection and separation between the distributed power supply and the commercial power supply, and a ground fault detection means for detecting a ground fault in the distributed power supply And a control unit for stopping the operation of the inverter circuit after disconnecting the disconnecting switch when the ground fault is detected by the ground fault detecting means.

【0011】[0011]

【発明の実施の形態】以下に本発明の実施の形態として
説明する回路構成は、従来構成と同様であるが制御手順
が異なっている。まず回路構成について具体的に説明す
る。図1に示すように、商用電源3は単相3線であって
漏電ブレーカよりなる主幹ブレーカ20を介して幹線に
接続される。負荷4には幹線を通して電力が供給され、
また、幹線には解列開閉器10を介して分散電源が接続
される。ここに、分岐ブレーカや連系ブレーカは本発明
の主旨ではないから図示していないが、一般には幹線か
ら負荷4への分岐点には分岐ブレーカを用い、また幹線
と解列開閉器10との間には連系ブレーカが挿入され
る。
DESCRIPTION OF THE PREFERRED EMBODIMENTS The circuit configuration described below as an embodiment of the present invention is the same as the conventional configuration, but the control procedure is different. First, the circuit configuration will be specifically described. As shown in FIG. 1, the commercial power supply 3 is a single-phase three-wire, and is connected to a main line via a main breaker 20 composed of an earth leakage breaker. Load 4 is supplied with power through the mains,
In addition, a distributed power supply is connected to the main line via a disconnecting switch 10. Here, the branch breaker and the interconnection breaker are not shown because they are not the gist of the present invention. However, in general, a branch breaker is used at a branch point from the main line to the load 4, and the branch breaker and the disconnecting switch 10 are generally used. An interconnection breaker is inserted between them.

【0012】分散電源は、太陽電池1を電源とし、昇圧
回路5、インバータ回路6、フィルタ回路7を用いて正
弦波状の交流電圧を出力するように構成されている。太
陽電池1は太陽電池セルを多数配列してパネル状とした
ものであり、太陽電池1の出力電圧は日射量に応じて変
化するが、ここでは出力電圧が0〜300Vの範囲で変
化する太陽電池1を想定している。分散電源は太陽電池
1の出力電圧がたとえば150V以上になる範囲で動作
させる。つまり、夜間や雨天など太陽電池1の出力が低
下している期間には分散電源は停止させる。この制御
は、図示していないが太陽電池1の出力電圧を監視する
ことにより行なっている。
The distributed power supply uses the solar cell 1 as a power supply and outputs a sine-wave AC voltage using a booster circuit 5, an inverter circuit 6, and a filter circuit 7. The solar cell 1 is a panel formed by arranging a large number of solar cells, and the output voltage of the solar cell 1 changes according to the amount of solar radiation. Here, the output voltage changes in the range of 0 to 300 V. Battery 1 is assumed. The distributed power source is operated in a range where the output voltage of the solar cell 1 becomes, for example, 150 V or more. That is, the distributed power supply is stopped during the period when the output of the solar cell 1 is low such as at night or in rainy weather. This control is performed by monitoring the output voltage of the solar cell 1 (not shown).

【0013】昇圧回路5は、商用電源3の交流電圧の実
効値(200V)の約1.4倍の出力電圧が得られるよ
うに昇圧するものであって、太陽電池1の出力端間に接
続されたリアクトル51とスイッチング素子52との直
列回路を備え、ダイオード53と平滑コンデンサ54と
の直列回路がスイッチング素子52に並列接続された構
成を備える。スイッチング素子52にはIGBTを用い
ており、ダイオード55が逆並列に接続されている。つ
まり、昇圧回路5は昇圧チョッパ回路として知られてい
る周知の構成を有し、スイッチング素子52を高周波で
オンオフさせ、スイッチング素子52のオン期間に太陽
電池1からリアクトル51にエネルギを蓄積し、スイッ
チング素子52のオフ期間にリアクトル51に誘起され
た両端電圧を太陽電池1の出力電圧に加算し、ダイオー
ド53を介して平滑コンデンサ54を充電するように構
成されている。したがって、スイッチング素子52のオ
ンオフのデューティ比を制御することによって平滑コン
デンサ54の出力電圧が調節可能になる。図示していな
いが昇圧回路5の出力電圧(平滑コンデンサ54の両端
電圧)は制御部8に入力されており、制御部8は昇圧回
路5の出力電圧を一定に保つようにスイッチング素子5
2のオンオフのデューティ比を制御する。
The booster circuit 5 boosts the output voltage so as to obtain an output voltage about 1.4 times the effective value (200 V) of the AC voltage of the commercial power supply 3 and is connected between the output terminals of the solar cell 1. A series circuit of a reactor 51 and a switching element 52 is provided, and a series circuit of a diode 53 and a smoothing capacitor 54 is connected to the switching element 52 in parallel. An IGBT is used for the switching element 52, and a diode 55 is connected in anti-parallel. In other words, the booster circuit 5 has a well-known configuration known as a booster chopper circuit, turns the switching element 52 on and off at a high frequency, stores energy from the solar cell 1 in the reactor 51 during the on-period of the switching element 52, and performs switching. The voltage between both ends induced in the reactor 51 during the off period of the element 52 is added to the output voltage of the solar cell 1, and the smoothing capacitor 54 is charged via the diode 53. Therefore, the output voltage of the smoothing capacitor 54 can be adjusted by controlling the on / off duty ratio of the switching element 52. Although not shown, the output voltage of the booster circuit 5 (the voltage across the smoothing capacitor 54) is input to the controller 8, and the controller 8 controls the switching element 5 so that the output voltage of the booster circuit 5 is kept constant.
2 is controlled.

【0014】一方、インバータ回路6は4個のスイッチ
ング素子61〜64によるブリッジ回路を構成したもの
であり、各一対のスイッチング素子61〜64からなる
直列回路をブリッジ回路の各アームとし、昇圧回路5の
平滑コンデンサ54に各アームを並列に接続した構成を
有する。また、各スイッチング素子61〜64にはそれ
ぞれダイオード65〜68が逆並列に接続される。スイ
ッチング素子61〜64は、一方のアームのハイサイド
(正極側)のスイッチング素子61,62がオンのとき
に、他方のアームのローサイド(負極側)のスイッチン
グ素子63,64がオンになるように制御部8により制
御される。また、スイッチング素子61〜64のオン期
間はPWM制御されており、図2 (b) (c)に示すよ
うに時間経過に伴って各スイッチング素子61〜64の
オン期間の幅を変化させることにより、時間積分を正弦
波状に変化させている。つまり、制御部8では、図2
(a)に示すように、一定周波数の三角波状の基準電圧
Vsを発生させるとともに正弦波状に変化する指令電圧
Veを発生させ、基準電圧Vsと指令電圧Veとを比較
することにより、スイッチング素子61〜64をオンに
するパルス幅を決定する。
On the other hand, the inverter circuit 6 constitutes a bridge circuit composed of four switching elements 61 to 64. A series circuit composed of a pair of switching elements 61 to 64 is used as each arm of the bridge circuit. Each arm is connected in parallel to the smoothing capacitor 54 of FIG. Diodes 65 to 68 are connected in antiparallel to the switching elements 61 to 64, respectively. The switching elements 61 to 64 are arranged such that when the switching elements 61 and 62 on the high side (positive side) of one arm are on, the switching elements 63 and 64 on the low side (negative side) of the other arm are on. It is controlled by the control unit 8. The on-periods of the switching elements 61 to 64 are PWM-controlled, and the width of the on-period of each of the switching elements 61 to 64 is changed with time as shown in FIGS. , The time integral is changed in the form of a sine wave. That is, in the control unit 8, FIG.
As shown in (a), a triangular wave reference voltage Vs having a constant frequency is generated and a command voltage Ve that changes sinusoidally is generated. By comparing the reference voltage Vs with the command voltage Ve, the switching element 61 is switched. Determine the pulse width to turn on ~ 64.

【0015】インバータ回路6から出力されるパルス電
圧はリアクトルL1,L2とコンデンサC1,C2より
なるフィルタ回路7に入力され、滑らかな正弦波状の電
圧波形が得られるようにしてある。ここに、フィルタ回
路7の出力電圧波形を商用電源3の電圧位相に一致させ
るように、制御部8はスイッチング素子61〜64のオ
ンオフのタイミングを調節する。つまり、インバータ回
路6は商用電源3に対して力率が1に保たれるように制
御される。
The pulse voltage output from the inverter circuit 6 is input to a filter circuit 7 composed of reactors L1 and L2 and capacitors C1 and C2 so that a smooth sinusoidal voltage waveform can be obtained. Here, the control unit 8 adjusts the on / off timing of the switching elements 61 to 64 so that the output voltage waveform of the filter circuit 7 matches the voltage phase of the commercial power supply 3. That is, the inverter circuit 6 is controlled so that the power factor of the commercial power supply 3 is maintained at 1.

【0016】地絡の検出についても従来構成と同様であ
って、太陽電池1と昇圧回路5との間などの適宜位置に
電流センサ11を配置し、電流センサ11の出力を判断
回路9に入力することにより地絡が生じているか否かが
判断される。ここで、図3に示す時刻taにおいて電流
センサ11の出力に基づいて判断回路9が地絡の発生を
検出すると、制御部8から解列開閉器10に対して解列
の指示が与えられる。この指示により解列開閉器10は
時刻tbにおいて解列する。この間、インバータ回路6
のスイッチング素子61〜64はオンオフの動作を継続
しており、解列開閉器10が解列した直後の時刻tcに
おいてインバータ回路6の動作を停止させる。解列開閉
器10は電磁接触器よりなり幹線に接続される主接点の
ほかに補助接点を備えているから、補助接点の開閉状態
を監視すれば解列開閉器10が解列したか否かを判断す
ることができる。
The detection of the ground fault is the same as that of the conventional configuration. The current sensor 11 is arranged at an appropriate position such as between the solar cell 1 and the booster circuit 5 and the output of the current sensor 11 is input to the judgment circuit 9. By doing so, it is determined whether a ground fault has occurred. Here, when the determination circuit 9 detects the occurrence of the ground fault based on the output of the current sensor 11 at the time ta shown in FIG. 3, the control unit 8 gives a disconnection instruction to the disconnection switch 10. With this instruction, the disconnecting switch 10 is disconnected at time tb. During this time, the inverter circuit 6
Of the switching elements 61 to 64 continue the on / off operation, and stop the operation of the inverter circuit 6 at time tc immediately after the disconnection switch 10 is disconnected. Since the disconnecting switch 10 is composed of an electromagnetic contactor and has an auxiliary contact in addition to the main contact connected to the main line, if the open / close state of the auxiliary contact is monitored, it is determined whether or not the disconnecting switch 10 is disconnected. Can be determined.

【0017】上述のように、地絡が生じたときには解列
開閉器10が解列した後に、インバータ回路6の動作を
停止させるから、地絡電流を半波整流した電流は主幹ブ
レーカ10に流れず、分散電源で生じた地絡によって主
幹ブレーカ10が遮断されるという誤動作を回避するこ
とができる。つまり、図4に示すように、時刻t1で地
絡が発生したとすると、時刻t2における解列開閉器1
0の解列までの期間に流れる地絡電流はほぼ一定の直流
になり、この電流は主幹ブレーカ10に内蔵した変流器
の出力には現れないから、漏電ブレーカである主幹ブレ
ーカ10で、この地絡電流が検出されることはなく、分
散電源で生じた地絡によって主幹ブレーカ10が遮断さ
れるのを防止することができるのである。図4における
横軸の1目盛は20m秒、縦軸の1目盛は50mAであ
る。また、図中のGは接地電位を示す。
As described above, when a ground fault occurs, the operation of the inverter circuit 6 is stopped after the disconnection switch 10 is disconnected. In addition, it is possible to avoid an erroneous operation in which the main breaker 10 is cut off by a ground fault generated in the distributed power supply. That is, as shown in FIG. 4, if a ground fault occurs at time t1, the disconnection switch 1 at time t2
The ground fault current flowing during the period until the zero disconnection becomes a substantially constant direct current, and this current does not appear in the output of the current transformer incorporated in the main breaker 10, so that the main breaker 10, which is an earth leakage breaker, No ground fault current is detected, and it is possible to prevent the main breaker 10 from being cut off by a ground fault generated by the distributed power supply. In FIG. 4, one scale on the horizontal axis is 20 ms, and one scale on the vertical axis is 50 mA. G in the figure indicates a ground potential.

【0018】[0018]

【発明の効果】本発明は、太陽電池から出力される直流
電圧を交流電圧に電力変換するインバータ回路を備えた
分散電源と、商用電源と幹線との間に接続された漏電ブ
レーカよりなる主幹ブレーカと、分散電源と幹線との間
に挿入され分散電源と商用電源との系統連系と系統分離
とを行なう解列開閉器と、分散電線における地絡を検出
する地絡検出手段と、地絡検出手段により地絡が検出さ
れると解列開閉器を解列した後にインバータ回路の動作
を停止させる制御部とを備えるものであり、地絡が発生
したときにインバータ回路を動作させた状態で解列開閉
器を解列させるから、地絡検出手段では地絡を検出する
が主幹ブレーカには直流に近い電流が流れるだけであっ
て、主幹ブレーカが誤動作するのを防止することができ
る。要するに分散電源において生じた地絡で主幹ブレー
カが動作することがなく、商用電源が正常であるにもか
かわらず主幹ブレーカが遮断されるという誤動作を防止
することができるのである。
According to the present invention, there is provided a main power circuit breaker comprising a distributed power supply having an inverter circuit for converting a DC voltage output from a solar cell into an AC voltage and an earth leakage breaker connected between a commercial power supply and a main line. A disconnector switch inserted between the distributed power supply and the main line to interconnect and separate the distributed power supply and the commercial power supply from each other; a ground fault detecting means for detecting a ground fault in the distributed electric wire; A control unit for stopping the operation of the inverter circuit after disconnecting the disconnection switch when a ground fault is detected by the detection means, and in a state where the inverter circuit is operated when a ground fault occurs. Since the disconnecting switch is disconnected, the ground fault is detected by the ground fault detecting means, but only a current close to DC flows through the main breaker, so that the main breaker can be prevented from malfunctioning. In short, the main breaker does not operate due to the ground fault generated in the distributed power supply, and it is possible to prevent an erroneous operation in which the main breaker is cut off even when the commercial power supply is normal.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明の実施の形態を示す回路図である。FIG. 1 is a circuit diagram showing an embodiment of the present invention.

【図2】同上の動作説明図である。FIG. 2 is an operation explanatory view of the above.

【図3】同上の動作説明図である。FIG. 3 is an operation explanatory view of the above.

【図4】同上の動作説明図である。FIG. 4 is an operation explanatory view of the above.

【図5】従来例の問題点を示す動作説明図である。FIG. 5 is an operation explanatory diagram showing a problem of the conventional example.

【図6】同上の動作説明図である。FIG. 6 is an operation explanatory view of the above.

【図7】同上の動作説明図である。FIG. 7 is an operation explanatory diagram of the above.

【符号の説明】[Explanation of symbols]

1 太陽電池 3 商用電源 6 インバータ回路 8 制御部 9 判断回路 10 解列開閉器 11 電流センサ 20 主幹ブレーカ DESCRIPTION OF SYMBOLS 1 Solar cell 3 Commercial power supply 6 Inverter circuit 8 Control part 9 Judgment circuit 10 Disconnection switch 11 Current sensor 20 Master breaker

───────────────────────────────────────────────────── フロントページの続き (72)発明者 小新 博昭 大阪府門真市大字門真1048番地松下電工株 式会社内 (72)発明者 向井 忠吉 大阪府門真市大字門真1048番地松下電工株 式会社内 (72)発明者 東浜 弘忠 大阪府門真市大字門真1048番地松下電工株 式会社内 (72)発明者 湯浅 裕明 大阪府門真市大字門真1048番地松下電工株 式会社内 Fターム(参考) 5G066 HA06 HA13 HB06  ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroaki Koshin 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor Tadayoshi Mukai 1048 Kadoma Kadoma, Kadoma City, Osaka Matsushita Electric Works Co., Ltd. (72) Inventor Hirotada Higashihama 1048 Kadoma, Kadoma, Osaka Pref. Matsushita Electric Works, Ltd. (72) Inventor Hiroaki Yuasa 1048 Kadoma, Kadoma, Kadoma, Osaka Pref. Matsushita Electric Works F-term (reference) 5G066 HA06 HA13 HB06

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 太陽電池から出力される直流電圧を交流
電圧に電力変換するインバータ回路を備えた分散電源
と、商用電源と幹線との間に接続された漏電ブレーカよ
りなる主幹ブレーカと、分散電源と幹線との間に挿入さ
れ分散電源と商用電源との系統連系と系統分離とを行な
う解列開閉器と、分散電源における地絡を検出する地絡
検出手段と、地絡検出手段により地絡が検出されると解
列開閉器を解列した後にインバータ回路の動作を停止さ
せる制御部とを備えることを特徴とする太陽光発電シス
テム。
1. A distributed power supply including an inverter circuit for converting a DC voltage output from a solar cell into an AC voltage, a main breaker including a ground leakage breaker connected between a commercial power supply and a main line, and a distributed power supply. A disconnection switch inserted between the power supply and the mains to perform system interconnection and system separation between the distributed power supply and the commercial power supply, ground fault detection means for detecting a ground fault in the distributed power supply, and ground fault detection means. And a control unit for stopping the operation of the inverter circuit after disconnecting the disconnection switch when a fault is detected.
JP18510698A 1998-06-30 1998-06-30 Solar power system Expired - Fee Related JP3533090B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP18510698A JP3533090B2 (en) 1998-06-30 1998-06-30 Solar power system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP18510698A JP3533090B2 (en) 1998-06-30 1998-06-30 Solar power system

Publications (2)

Publication Number Publication Date
JP2000023368A true JP2000023368A (en) 2000-01-21
JP3533090B2 JP3533090B2 (en) 2004-05-31

Family

ID=16164969

Family Applications (1)

Application Number Title Priority Date Filing Date
JP18510698A Expired - Fee Related JP3533090B2 (en) 1998-06-30 1998-06-30 Solar power system

Country Status (1)

Country Link
JP (1) JP3533090B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080143554A1 (en) * 2004-07-09 2008-06-19 Ezra Green Remote access energy meter system and method
CN102904279A (en) * 2012-09-29 2013-01-30 西安龙腾新能源科技发展有限公司 Inverter circuit topology and control method thereof
KR101234819B1 (en) * 2011-07-13 2013-02-20 (주)금성계전 Dc leakage current circuit braker

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080143554A1 (en) * 2004-07-09 2008-06-19 Ezra Green Remote access energy meter system and method
KR101234819B1 (en) * 2011-07-13 2013-02-20 (주)금성계전 Dc leakage current circuit braker
CN102904279A (en) * 2012-09-29 2013-01-30 西安龙腾新能源科技发展有限公司 Inverter circuit topology and control method thereof

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