JP2002034175A - Solar power generating equipment - Google Patents
Solar power generating equipmentInfo
- Publication number
- JP2002034175A JP2002034175A JP2000214310A JP2000214310A JP2002034175A JP 2002034175 A JP2002034175 A JP 2002034175A JP 2000214310 A JP2000214310 A JP 2000214310A JP 2000214310 A JP2000214310 A JP 2000214310A JP 2002034175 A JP2002034175 A JP 2002034175A
- Authority
- JP
- Japan
- Prior art keywords
- power
- voltage
- storage battery
- solar cell
- control
- 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
Links
Classifications
-
- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
-
- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、電力系統あるいは
他の発電設備と連系運転を行う太陽光発電装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic power generator which operates in connection with a power system or other power generation equipment.
【０００２】[0002]
【従来の技術】太陽光発電システムとしては、太陽電池
の直流電力を交流に変換し、既存の電力系統に連系して
運転するシステムが実用化されている。この種システム
の中には、災害時や系統事故時にも運転が可能なよう
に、太陽電池に並列に蓄電池を設置したシステムがあ
る。このようなシステムの構成例としては、例えば図２
に示す特開平９−４６９２５号公報に記載のシステムが
ある。図２において、太陽電池１は、電力変換器４に接
続されるとともに、切替回路（スイッチ２ａ，２ｃ，２
ｅ、整流器２ｂ、抵抗２ｄからなる）２を介して蓄電池
３に接続されている。電力変換器４は、直流電力を交流
電力に変換し、連系装置５Ａを介して系統８と連系運転
を行い、一般負荷６に電力を供給している。負荷として
は一般負荷６の他に連系装置５Ｂを介して自立運転負荷
７が接続されている。自立運転負荷７は、通常時には一
般負荷６と同様に系統８と電力変換器４の両方から電力
供給を受けるが、系統事故などにより、系統８から電力
供給が不可能な場合には蓄電池３を使用して電力供給が
行われる。上記の太陽光発電システムの運転方法は、系
統８が正常な場合には切替回路２のスイッチ２ｃ、２ｅ
が開放されており、電力変換器４は太陽電池１からのみ
電力供給をうけ、最大電力追従制御を行い、太陽電池１
からの発電電力が最大となるように運転し、系統８へ電
力供給を行っている。系統８が何らかの異常で停電した
場合には、電力変換器４の運転を一旦停止し、切替回路
２のスイッチ２ｅ、２ｃの順番に投入し、連系装置５Ａ
を開放、連系装置５Ｂを投入し、再度運転し、自立運転
負荷７に太陽電池１と蓄電池３から電力を供給する。と
ころで、このような蓄電池３を設置した自立運転機能付
きのシステムでは、蓄電池３が使用されるのは、系統停
電などの事態の時だけであり、その他の殆どの時は利用
されず、蓄電池３の利用率が非常に低い。そのため、蓄
電池３を有効利用することを目的に、蓄電池３の貯蔵電
力の一部を一般負荷６の電力供給にも使用する利用方法
が考えられている。この利用方法の一例として、負荷電
力のピ−クカット運転があるが、これを図３を用いて説
明する。図２のシステムで系統８から受電している電力
トレンドが図３（ａ）の受電電力ＰＬとする。図２では
負荷に太陽電池１から電力供給を行っているため、受電
電力は減少しているが、それでもＰＬのような電力を受
電している状態とする。この時、電力制限値Ｐｄに受電
電力ＰＬを抑制したいとすると、電力変換器４からさら
に図３（ｂ）に示す電力を供給すれば良い。つまり、切
替回路２で時刻ｔ１〜ｔ２にわたって蓄電池３を太陽電
池１に並列に接続し、図３（ｂ）のピ−クカット電力出
力指令Ｐｃを電力変換器４に与えることによりに、ピ−
クカット運転が可能となる。このような運転を行うこと
により、蓄電池３の貯蔵電力の一部を有効利用しなが
ら、非常時の自立運転も可能なシステムを達成すること
ができる。なお、ピ−クカット運転のために、蓄電池３
から放電された電力は、太陽電池１が発電できない夜間
に電力変換器４を整流器運転し、系統電力によって充電
される。2. Description of the Related Art As a photovoltaic power generation system, a system that converts DC power of a solar cell into AC and operates in connection with an existing power system has been put to practical use. Among such systems, there is a system in which a storage battery is installed in parallel with a solar cell so that operation is possible even in the event of a disaster or a system accident. As an example of the configuration of such a system, for example, FIG.
There is a system described in JP-A-9-46925. In FIG. 2, a solar cell 1 is connected to a power converter 4 and a switching circuit (switches 2a, 2c, 2).
e, a rectifier 2b, and a resistor 2d) 2). The power converter 4 converts DC power into AC power, performs a connection operation with the system 8 via the connection device 5A, and supplies power to the general load 6. As the load, in addition to the general load 6, an independent operation load 7 is connected via the interconnection device 5B. The autonomous operation load 7 normally receives power supply from both the system 8 and the power converter 4 like the general load 6. However, when power supply from the system 8 is impossible due to a system accident or the like, the storage battery 3 is used. Power supply. The above-described method of operating the photovoltaic power generation system uses the switches 2c and 2e of the switching circuit 2 when the system 8 is normal.
Are open, the power converter 4 receives power supply only from the solar cell 1 and performs maximum power tracking control,
The system is operated so that the power generated from the system becomes maximum, and power is supplied to the system 8. If the system 8 fails due to any abnormality, the operation of the power converter 4 is temporarily stopped, and the switches 2e and 2c of the switching circuit 2 are turned on in this order to connect the interconnection device 5A.
Is released, the interconnection device 5B is turned on, the operation is performed again, and power is supplied to the independent operation load 7 from the solar cell 1 and the storage battery 3. By the way, in such a system with the self-sustaining operation function in which the storage battery 3 is installed, the storage battery 3 is used only in the event of a system power failure or the like, and is not used in most other cases. Very low utilization. Therefore, in order to use the storage battery 3 effectively, a method of using a part of the storage power of the storage battery 3 to supply power to the general load 6 has been considered. One example of this utilization method is a peak cut operation of load power, which will be described with reference to FIG. The power trend received from the grid 8 in the system of FIG. 2 is the received power PL of FIG. In FIG. 2, the power is supplied from the solar cell 1 to the load, so the received power is reduced. However, it is assumed that power such as PL is still received. At this time, if it is desired to suppress the received power PL to the power limit value Pd, the power shown in FIG. That is, the storage circuit 3 is connected in parallel to the solar cell 1 by the switching circuit 2 from time t1 to time t2, and the peak cut power output command Pc in FIG.
Kukat operation becomes possible. By performing such an operation, it is possible to achieve a system capable of performing an independent operation in an emergency while effectively utilizing a part of the storage power of the storage battery 3. In addition, the storage battery 3 is used for the peak cut operation.
The power discharged from is operated by the rectifier of the power converter 4 at night when the solar cell 1 cannot generate power, and is charged by the system power.
【０００３】[0003]
【発明が解決しようとする課題】上記の従来システムに
おいては、先に説明したように、太陽電池１だけ接続さ
れた時には、太陽電池１から最大電力を取り出すため
に、最大電力追従制御を行う。しかし、蓄電池３を接続
した場合には、蓄電池３の内部インピ−ダンスが非常に
小さく、直流電圧は蓄電池３で決まってしまうので、最
大電力制御を行うことができない。したがって、従来シ
ステムではピ−クカット運転を行う場合には、一旦電力
変換器４を停止し、切替回路２で蓄電池３を接続し、制
御方式も切り替えた後に再度電力変換器４を立ち上げ、
系統８に接続後、ピ−クカット運転を開始するなどの非
常に煩わしい手段を採っていた。また、運転切替時に
は、切替回路２のスイッチを投入、開放するため、これ
らスイッチの寿命の問題もあった。In the above-described conventional system, as described above, when only the solar cell 1 is connected, the maximum power follow-up control is performed to extract the maximum electric power from the solar cell 1. However, when the storage battery 3 is connected, since the internal impedance of the storage battery 3 is very small and the DC voltage is determined by the storage battery 3, the maximum power control cannot be performed. Therefore, in the conventional system, when the peak cut operation is performed, the power converter 4 is temporarily stopped, the storage battery 3 is connected by the switching circuit 2, the control method is also switched, and then the power converter 4 is started again.
After connecting to the system 8, a very troublesome means such as starting a peak cut operation was employed. Further, when the operation is switched, the switches of the switching circuit 2 are turned on and off, so that there is a problem of the life of these switches.
【０００４】本発明の課題は、蓄電池が並列に接続され
た太陽光発電設備において、蓄電池併用運転と太陽電池
のみの運転を煩雑な切替操作なしに運転可能な太陽光発
電装置を提供することにある。[0004] It is an object of the present invention to provide a photovoltaic power generation system in which a storage battery is connected in parallel and which can be operated without complicated switching operation between the combined operation of the storage battery and the operation of only the solar cell. is there.
【０００５】[0005]
【課題を解決するための手段】上記課題を解決するため
に、太陽電池と充放電手段を介して並列に接続された蓄
電池と、太陽電池の出力電力を交流電力に変換し、他の
交流電源と連系する電力変換器と、太陽電池の出力が増
加する方向へ動作指令を変化させる最大電力追従制御手
段と、太陽電池の電圧を一定に制御する直流定電圧制御
手段と、外部からの電力指令による制御を行う手段を備
えた太陽光発電装置であって、蓄電池の電圧を太陽電池
の直流定電圧より小さい値とするように設定し、蓄電池
の電圧が太陽電池の電圧よりも小さいときに、蓄電池の
放電を阻止する。ここで、蓄電池から電力供給を行わな
い場合には、太陽電池の最大電力追従制御または直流定
電圧制御を行い、蓄電池から電力供給を行う場合には、
外部からの電力指令にしたがって制御を行う。また、蓄
電池に電流検出器を設け、最大電力追従制御時あるいは
直流定電圧制御時に蓄電池の放電電流を検出したとき、
直流回路電圧の設定値を変更する補正手段を備える。ま
た、蓄電池に電流検出器および直流−直流変換器を接続
し、電流検出器によって検出された蓄電池出力電圧を直
流回路電圧の設定値より低くするように直流−直流変換
器を制御する直流電圧調整手段を備える。In order to solve the above-mentioned problems, a storage battery connected in parallel with a solar cell via charging / discharging means and an output power of the solar cell are converted into AC power, and another AC power supply is provided. A power converter interconnected with the power supply, a maximum power follow-up control means for changing an operation command in a direction to increase the output of the solar cell, a DC constant voltage control means for controlling the voltage of the solar cell to be constant, and an external power supply. A solar power generation device comprising means for performing control by a command, wherein the voltage of the storage battery is set to a value smaller than the DC constant voltage of the solar cell, and the voltage of the storage battery is lower than the voltage of the solar cell. To prevent the storage battery from discharging. Here, when power is not supplied from the storage battery, maximum power follow-up control or DC constant voltage control of the solar cell is performed, and when power is supplied from the storage battery,
Control is performed according to an external power command. Also, a current detector is provided in the storage battery, and when the discharge current of the storage battery is detected during the maximum power follow-up control or the DC constant voltage control,
A correction means for changing a set value of the DC circuit voltage is provided. A DC voltage controller for connecting a current detector and a DC-DC converter to the storage battery and controlling the DC-DC converter so that the output voltage of the storage battery detected by the current detector is lower than a set value of the DC circuit voltage. Means.
【０００６】[0006]
【発明の実施の形態】以下、本発明の実施形態を図面を
参照して説明する。図１は、本発明の太陽光発電装置で
ある第一の実施形態を示す。図２で説明した従来技術と
同一番号の構成は図２と同一の機能を有する。図１にお
いて、太陽電池１は、充電ブロック回路３０を介して蓄
電池３と並列に接続され、電力変換器４に電力を供給す
る。充電ブロック回路３０内のスイッチ３０Ｓは通常開
放され、後で説明する蓄電池３の充電時の時のみ接続さ
れる。ここで、蓄電池３の直流電圧は、以下で説明する
直流定電圧設定回路２２によって指示される電圧以下に
設定されている。このため、太陽電池１の方が蓄電池電
圧より高いので、充電ブロック回路３０内のダイオード
３０ｄは逆方向にバイアスされ、蓄電池３からの電力放
電はない。したがって、電力変換器４への電力の入力は
太陽電池１の出力だけとなる。太陽電池１の出力は電力
変換器４で交流に変換され、連系スイッチ５を介して電
力系統８に接続され、一般負荷６に電力が供給される。
一方、太陽電池１で発電された電圧、電流は電流検出器
９、電圧検出器１０を介して電力検出回路２０に送ら
れ、太陽電池１の出力電力が演算される。電力検出回路
２０の出力は、最大電力追従回路２１に送られ、ここで
太陽電池１の最大電力が得られる直流電圧指令が出力さ
れる。最大電力追従制御は、日射強度が強いときには太
陽電池１の直流電圧を変えることにより、有効に電力を
取り出すことができるが、日射強度が弱いときには直流
定電圧で太陽電池１を制御しても効果は変わらなくな
る。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment which is a photovoltaic power generator of the present invention. 2 have the same functions as those of FIG. In FIG. 1, a solar cell 1 is connected in parallel with a storage battery 3 via a charging block circuit 30, and supplies power to a power converter 4. The switch 30S in the charging block circuit 30 is normally opened, and is connected only when the storage battery 3 described later is charged. Here, the DC voltage of the storage battery 3 is set to be equal to or lower than the voltage specified by the DC constant voltage setting circuit 22 described below. For this reason, since the solar cell 1 is higher than the storage battery voltage, the diode 30d in the charging block circuit 30 is biased in the reverse direction, and no power is discharged from the storage battery 3. Therefore, the power input to the power converter 4 is only the output of the solar cell 1. The output of the solar cell 1 is converted into AC by the power converter 4, connected to the power system 8 via the interconnection switch 5, and supplied with power to the general load 6.
On the other hand, the voltage and current generated by the solar cell 1 are sent to the power detection circuit 20 via the current detector 9 and the voltage detector 10, and the output power of the solar cell 1 is calculated. The output of the power detection circuit 20 is sent to a maximum power follow-up circuit 21, where a DC voltage command for obtaining the maximum power of the solar cell 1 is output. The maximum power tracking control can effectively extract power by changing the DC voltage of the solar cell 1 when the solar irradiance is strong. However, when the solar irradiance is weak, it is effective to control the solar cell 1 with a constant DC voltage. Will not change.
【０００７】図４は、上記の理由を説明するための太陽
電池特性図であり、太陽電池の出力特性について、日射
強度を１１＞１２＞１３の３ケースとした場合の太陽電
池の電圧−電流特性Ｌ１〜Ｌ３およびで電圧−電力特性
Ｐ１〜Ｐ３を示したものである。この特性図から分かる
ように、太陽電池の最大電力は、日射強度１１が十分に
ある場合には直流電圧を制御することにより、大きく変
化するが、日射強度１３が小さくなると、最大電力を得
る直流電圧が低下するとともにピークが平坦となり、直
流電圧によって電力は大きく変化しない特性となる。あ
る日射強度以下の場合には、直流電圧一定制御しても効
果は殆ど変わらなくなる。そのため、最大電力追従制御
の結果、直流電圧が一定値以下になった場合には、その
電圧で直流定電圧制御を行うことが多い。このため、図
１では最大電力追従運転から直流定電圧制御の移行電圧
値Ｖｄを直流定電圧設定回路２２によって設定してお
く。FIG. 4 is a graph showing the characteristics of a solar cell for explaining the above-mentioned reasons. As for the output characteristics of the solar cell, the voltage-current of the solar cell when the solar radiation intensity is in three cases of 11>12> 13 The characteristics L1 to L3 and the voltage-power characteristics P1 to P3 are shown. As can be seen from the characteristic diagram, the maximum power of the solar cell changes greatly by controlling the DC voltage when the solar radiation intensity 11 is sufficient, but when the solar radiation intensity 13 decreases, the DC power for obtaining the maximum power increases. As the voltage decreases, the peak becomes flat, and the power does not greatly change due to the DC voltage. When the solar radiation intensity is lower than a certain value, the effect hardly changes even if the DC voltage is controlled to be constant. Therefore, when the DC voltage falls below a certain value as a result of the maximum power follow-up control, the DC constant voltage control is often performed at that voltage. For this reason, in FIG. 1, the transition voltage value Vd of the DC constant voltage control from the maximum power following operation is set by the DC constant voltage setting circuit 22.
【０００８】高電圧選定回路２３は、最大電力追従回路
２１の出力値と定電圧設定回路２２の出力とを比較し、
どちらか高い方の電圧を優先的に選択する回路であり、
日射強度が強い状態では最大電力追従回路２１の方が大
きいので、こちらを選択するが、夕暮れ時や天候が悪く
出力がでない場合などは、最大電力追従回路２１の出力
が定電圧設定回路２２の出力以下になり、定電圧設定回
路２２の出力を選択する。以上により、通常運転制御
は、太陽電池１の最大電力追従制御となるため、高電圧
選定回路２３は最大電力追従回路２１の信号を選択し、
直流電圧制御回路２４に信号を送る。直流電圧制御回路
２４の出力信号２４ａは、切替器２６に送られる。切替
器２６は、外部電力指令回路２５の電力指令２５ａと、
直流電圧制御回路２４の出力を切り替え選択し、通常運
転時は直流電圧制御回路２４の出力信号２４ａが選択さ
れる。直流制御回路２４の出力信号２４ａは電流制御回
路２７に入力され、また、電流検出器１１によって検出
された電力変換器４の出力電流を電流制御回路２７に入
力し、ゲート回路２８を介して電流制御回路２７の出力
によって電力変換器４を制御し、太陽電池１の直流電圧
を最大電力値となるように運転を行う。このように、外
部からの電力指令２５ａがない状態では、従来と同様太
陽電池１の最大電力追従制御が実施される。The high voltage selection circuit 23 compares the output value of the maximum power tracking circuit 21 with the output of the constant voltage setting circuit 22,
This is a circuit that preferentially selects the higher voltage,
The maximum power follow-up circuit 21 is selected when the solar radiation intensity is high because the maximum power follow-up circuit 21 is larger. However, at dusk or when the weather is bad and the output is not available, the output of the maximum power follow-up circuit 21 The output becomes equal to or less than the output, and the output of the constant voltage setting circuit 22 is selected. As described above, since the normal operation control is the maximum power tracking control of the solar cell 1, the high voltage selection circuit 23 selects the signal of the maximum power tracking circuit 21,
A signal is sent to the DC voltage control circuit 24. The output signal 24a of the DC voltage control circuit 24 is sent to the switch 26. The switch 26 includes a power command 25a of the external power command circuit 25,
The output of the DC voltage control circuit 24 is switched and selected, and during normal operation, the output signal 24a of the DC voltage control circuit 24 is selected. The output signal 24a of the DC control circuit 24 is input to the current control circuit 27, and the output current of the power converter 4 detected by the current detector 11 is input to the current control circuit 27. The power converter 4 is controlled by the output of the control circuit 27, and operation is performed so that the DC voltage of the solar cell 1 becomes the maximum power value. As described above, when there is no external power command 25a, the maximum power tracking control of the solar cell 1 is performed as in the related art.
【０００９】さて、上記の運転中に、図３（ｂ）に示す
ように、時刻ｔ１〜ｔ２にかけて負荷のピークカット運
転を行う場合には、外部電力指令回路２５から図３
（ｂ）に示すピークカット電力出力指令Ｐｃを出力して
おき、タイマー回路２９により切替器２６を外部電力指
令回路２５の電力指令２５ａを選択するように切り替え
る。このように制御指令が外部からの電力指令２５ａに
切り替わると、電力変換器４の制御は今まで述べてきた
最大電力追従制御から、外部電力指令による電力指令に
切り替わる。つまり、太陽電池１の直流電圧制御が開放
され、電力変換器４の出力が外部電力指令回路２５の電
力指令２５ａと一致するように動作する電力制御とな
る。一方、外部電力指令回路２５の指令値は現状の出力
にさらにＰｃ分の電力を出力する指令となるので、太陽
電池１の最大電力値よりも大きい値となり、太陽電池は
この電力を負担できない。このため、太陽電池１の出力
電圧は低下し、蓄電池電圧Ｖｂの値まで低下し、蓄電池
３から不足電力を供給するように動作する。つまり、図
５に示すように、ＶｍａｘのＡ点で太陽電池１が運転し
ていたときに、タイマー回路２９から切替指令が出力さ
れ、切替器２６が外部電力指令回路２５を選択すると、
図３（ｂ）の電力指令Ｐｃが出力され、この電力指令Ｐ
ｃは太陽電池１の最大電力値以上のため、直流電流が増
大し、太陽電池１はＶｍａｘ電圧を維持できなく、電圧
−電流特性にしたがって電圧が低下する。太陽電池電圧
が蓄電池電圧ＶｂのＢ点まで低下すると、今まで通電が
阻止されていた充電ブロック回路３０のダイオード３０
ｄが導通し、蓄電池３からの電力供給が開始される。蓄
電池３は、内部インピーダンスが低いため、外部電力指
令回路２５の指令値の電力を十分供給可能なため、直流
電圧は蓄電池電圧Ｖｂに維持され、電力供給と見合う電
流のＣ点で運転を行うことになる。したがって、ピーク
カット運転時間内のｔ１〜ｔ２までの時間帯は、外部電
力指令回路２５の指令値の電力が電力変換器４から出力
される。ピークカット運転が終了する時刻ｔ２に達する
と、タイマー回路２９は切替器２６の選択を直流制御回
路２４の出力側に切り替える。この時、切り替える前の
直流電圧は蓄電池電圧Ｖｂとなっており、直流定電圧設
定回路２２の設定値Ｖｄよりも低い値となっている。こ
のため、高電圧選択回路２３では直流定電圧設定回路２
２の指令値Ｖｄを選択するので、直流電圧制御回路２４
はこの電圧値となるように電力変換器４を制御する。こ
の結果、直流回路電圧はＶｄとなるが、Ｖｄは蓄電池電
圧Ｖｂより高いので、充電ブロック回路３０のダイオー
ド３０ｄは再び逆方向にバイアスされ、導通が阻止され
る。このため、蓄電池３からの電力供給はなくなり、太
陽電池１からのみの電力供給に自動的に戻ることにな
る。したがって、以後太陽電池１の最大電力追従制御が
再び可能となる。During the above operation, as shown in FIG. 3 (b), when the peak cut operation of the load is performed from time t1 to time t2, the external power command circuit 25 outputs
The peak cut power output command Pc shown in (b) is output, and the switch 26 is switched by the timer circuit 29 so as to select the power command 25a of the external power command circuit 25. When the control command is switched to the power command 25a from the outside in this way, the control of the power converter 4 is switched from the maximum power tracking control described so far to a power command based on the external power command. That is, the DC voltage control of the solar cell 1 is released, and the power control is operated such that the output of the power converter 4 matches the power command 25a of the external power command circuit 25. On the other hand, since the command value of the external power command circuit 25 is a command to output power of Pc in addition to the current output, the command value becomes larger than the maximum power value of the solar cell 1, and the solar cell cannot bear this power. For this reason, the output voltage of the solar cell 1 decreases, decreases to the value of the storage battery voltage Vb, and operates to supply insufficient power from the storage battery 3. That is, as shown in FIG. 5, when the solar cell 1 is operating at the point A of Vmax, a switching command is output from the timer circuit 29, and when the switch 26 selects the external power command circuit 25,
The power command Pc shown in FIG.
Since c is equal to or greater than the maximum power value of the solar cell 1, the DC current increases, the solar cell 1 cannot maintain the Vmax voltage, and the voltage decreases according to the voltage-current characteristics. When the solar cell voltage drops to the point B of the storage battery voltage Vb, the diode 30 of the charging block circuit 30 which has been blocked from being energized up to now.
d conducts, and power supply from the storage battery 3 is started. Since the storage battery 3 has a low internal impedance and can sufficiently supply the power of the command value of the external power command circuit 25, the DC voltage is maintained at the storage battery voltage Vb, and the operation is performed at the point C of the current corresponding to the power supply. become. Therefore, the power of the command value of the external power command circuit 25 is output from the power converter 4 during the time period from t1 to t2 within the peak cut operation time. When the time t2 at which the peak cut operation ends is reached, the timer circuit 29 switches the selection of the switch 26 to the output side of the DC control circuit 24. At this time, the DC voltage before switching is the storage battery voltage Vb, which is lower than the set value Vd of the DC constant voltage setting circuit 22. Therefore, in the high voltage selection circuit 23, the DC constant voltage setting circuit 2
2 is selected, so that the DC voltage control circuit 24
Controls the power converter 4 to have this voltage value. As a result, the DC circuit voltage becomes Vd, but since Vd is higher than the storage battery voltage Vb, the diode 30d of the charging block circuit 30 is again biased in the reverse direction, and conduction is prevented. Therefore, the power supply from the storage battery 3 is stopped, and the power supply from the solar cell 1 alone is automatically returned to. Therefore, the maximum power follow-up control of the solar cell 1 becomes possible again thereafter.
【００１０】以上で説明したように、本実施形態では、
蓄電池３の電圧Ｖｂを直流定電圧設定回路２２の設定電
圧Ｖｄより低い電圧になるように設定し、また、蓄電池
３と直列に充電ブロック回路３０を設けることにより、
煩雑な切替操作をなくして自動的に太陽電池１の最大電
力追従制御およびピークカット運転が可能となる。な
お、充電ブロック回路３０のスイッチ３０Ｓは常時は開
放されており、夜太陽電池が発電できなくなる時間帯に
投入し、電力変換器４によって系統８の電力を使用して
日中に放電した電力を充電する。充電を完了した時点で
スイッチ３０Ｓは再び開放される。As described above, in the present embodiment,
By setting the voltage Vb of the storage battery 3 to be lower than the set voltage Vd of the DC constant voltage setting circuit 22, and providing the charging block circuit 30 in series with the storage battery 3,
It is possible to automatically perform the maximum power follow-up control and the peak cut operation of the solar cell 1 without complicated switching operation. The switch 30S of the charging block circuit 30 is always open, and is turned on at a time when the solar cell cannot generate power at night, and the power discharged during the day by using the power of the system 8 by the power converter 4 is used. Charge. When the charging is completed, the switch 30S is opened again.
【００１１】図６は、本発明の第二の実施形態を示す。
図１の第一の実施形態と異なる点は、蓄電池３に電流検
出器４０を設置し、最大電力追従回路２１および直流定
電圧設定回路２２にそれぞれ電圧補正回路４１、４２を
接続することにある。蓄電池３の電流検出器４０は蓄電
池３の放電電流を監視し、太陽電池１の最大電力追従運
転時、あるいは、直流定電圧運転時に電流検出器４０に
よって蓄電池３の放電電流が検出された場合には、電圧
補正回路４１、４２により電圧指令値を上昇させ、電流
検出器４０の電流が検出されなくなるまで電圧の設定値
の補正を自動的に行う。これにより、太陽電池１の最大
電力追従運転あるいは直流定電圧運転を有効に行うこと
ができ、太陽電池１の電力利用率を向上させることがで
きる。FIG. 6 shows a second embodiment of the present invention.
The difference from the first embodiment in FIG. 1 is that a current detector 40 is provided in the storage battery 3 and voltage correction circuits 41 and 42 are connected to the maximum power tracking circuit 21 and the DC constant voltage setting circuit 22, respectively. . The current detector 40 of the storage battery 3 monitors the discharge current of the storage battery 3, and when the discharge current of the storage battery 3 is detected by the current detector 40 during the maximum power following operation of the solar cell 1 or the DC constant voltage operation. Increases the voltage command value by the voltage correction circuits 41 and 42, and automatically corrects the set value of the voltage until the current of the current detector 40 is no longer detected. Thereby, the maximum power following operation or the DC constant voltage operation of the solar cell 1 can be effectively performed, and the power utilization rate of the solar cell 1 can be improved.
【００１２】図７は、本発明の第三の実施形態を示す。
図１の第一の実施形態と異なる点は、蓄電池３に電流検
出器４０および直流−直流変換器５０を接続し、この直
流−直流変換器５０と直流定電圧設定回路２２の間に直
流電圧調整回路５２および電圧バイアス設定回路５３を
設けることにある。直流−直流変換器５０は、蓄電池３
の電圧を可変し、直流定電圧設定回路２２の設定電圧よ
り低い電圧に蓄電池出力電圧を制御する。電圧バイアス
設定回路５３は、直流定電圧設定回路２２の設定電圧に
対してある一定値分だけ常に低い電圧を出力する。直流
電圧調整回路５２は、電圧バイアス設定回路５３の信号
を指令値とし、電流検出器５１によって検出された蓄電
池出力電圧が電圧バイアス設定回路５３の出力と同じく
なるように直流−直流変換器５０を制御する。直流定電
圧設定回路２２の設定電圧は電圧バイアス設定回路５３
に入力され、電圧バイアス設定回路５３から直流定電圧
設定回路２２の設定電圧より常に低い電圧が出力され
る。直流電圧調整回路５２では、電流検出器５１によっ
て検出された蓄電池出力電圧と電圧バイアス設定回路５
３の出力電圧に基づいて蓄電池出力電圧が直流定電圧設
定回路２２の設定電圧より低い電圧になるように直流−
直流変換器５０を制御する。これにより、蓄電池３の電
圧が太陽電池運転電圧よりも高くとも、直流−直流変換
器５０によって蓄電池３の出力電圧を直流定電圧設定回
路２２の設定電圧より低くすることができ、図１と同じ
効果が得られる。FIG. 7 shows a third embodiment of the present invention.
The difference from the first embodiment of FIG. 1 is that a current detector 40 and a DC-DC converter 50 are connected to the storage battery 3, and a DC voltage is applied between the DC-DC converter 50 and the DC constant voltage setting circuit 22. An adjustment circuit 52 and a voltage bias setting circuit 53 are provided. The DC-DC converter 50 includes the storage battery 3
And the output voltage of the storage battery is controlled to a voltage lower than the voltage set by the DC constant voltage setting circuit 22. The voltage bias setting circuit 53 outputs a voltage that is always lower by a certain value than the set voltage of the DC constant voltage setting circuit 22. The DC voltage adjustment circuit 52 uses the signal of the voltage bias setting circuit 53 as a command value, and controls the DC-DC converter 50 so that the storage battery output voltage detected by the current detector 51 becomes the same as the output of the voltage bias setting circuit 53. Control. The set voltage of the DC constant voltage setting circuit 22 is a voltage bias setting circuit 53.
, And a voltage that is always lower than the set voltage of the DC constant voltage setting circuit 22 is output from the voltage bias setting circuit 53. In the DC voltage adjusting circuit 52, the storage battery output voltage detected by the current detector 51 and the voltage bias setting circuit 5
3 so that the output voltage of the storage battery becomes lower than the voltage set by the DC constant voltage setting circuit 22 based on the output voltage of
The DC converter 50 is controlled. Thereby, even if the voltage of the storage battery 3 is higher than the solar cell operation voltage, the output voltage of the storage battery 3 can be made lower than the set voltage of the DC constant voltage setting circuit 22 by the DC-DC converter 50, and the same as FIG. The effect is obtained.
【００１３】[0013]
【発明の効果】以上説明したように、本発明によれば、
太陽電池だけを使用した最大電力追従運転から蓄電池の
貯蔵電力を使用した運転への切替あるいはその反対の切
替操作も煩雑な操作を行うことなく、自動的に切り替え
ることが可能となる。また、蓄電池の電圧を太陽電池の
直流定電圧より小さい値とするように設定するので、太
陽電池だけからの電力供給モードでも蓄電池からの電力
供給モードにおいても、電力変換器停止操作、切替操作
の煩わしさがを伴わず、運転が可能となり、また、太陽
電池の電力利用率を上げることができる。また、電力供
給モードの運転切替時に用いる切替用のスイッチの省設
備化により、メンテナンスが容易になり、低コスト化を
図ることができる。また、太陽電池の最大電力追従運転
時あるいは直流定電圧運転時に蓄電池の放電電流が検出
された場合には、蓄電池の出力電圧より直流回路の電圧
指令値を上昇させるように自動的に補正するので、太陽
電池の最大電力追従運転あるいは直流定電圧運転を有効
に行うことができ、太陽電池の電力利用率を向上させる
ことができる。また、太陽電池の最大電力追従運転時あ
るいは直流定電圧運転時に蓄電池の放電電流が検出され
た場合には、蓄電池の出力電圧を直流定電圧制御の設定
電圧より低くするので、太陽電池の最大電力追従運転あ
るいは直流定電圧運転を有効に行うことができ、太陽電
池の電力利用率を向上させることができる。As described above, according to the present invention,
The switching from the maximum power following operation using only the solar cell to the operation using the stored power of the storage battery or the opposite switching operation can be automatically performed without performing a complicated operation. Further, since the voltage of the storage battery is set to a value smaller than the DC constant voltage of the solar battery, the power converter stop operation and the switching operation can be performed in the power supply mode from the solar battery alone or in the power supply mode from the storage battery. Operation can be performed without any inconvenience, and the power utilization rate of the solar cell can be increased. In addition, maintenance can be facilitated and cost can be reduced by reducing the number of switches used for switching operation in the power supply mode. In addition, when the discharge current of the storage battery is detected during the maximum power following operation of the solar cell or the DC constant voltage operation, the voltage command value of the DC circuit is automatically corrected to be higher than the output voltage of the storage battery. In addition, the maximum power following operation or the DC constant voltage operation of the solar cell can be effectively performed, and the power utilization rate of the solar cell can be improved. When the discharge current of the storage battery is detected during the maximum power following operation of the solar cell or the DC constant voltage operation, the output voltage of the storage battery is set lower than the set voltage of the DC constant voltage control. The follow-up operation or the DC constant voltage operation can be effectively performed, and the power utilization rate of the solar cell can be improved.
【図面の簡単な説明】[Brief description of the drawings]
【図１】本発明の太陽光発電装置である第一の実施形態
を示す構成図FIG. 1 is a configuration diagram showing a first embodiment which is a solar power generation device of the present invention.
【図２】従来例による太陽光発電システムFIG. 2 shows a conventional solar power generation system.
【図３】ピークカット電力を説明する図FIG. 3 is a diagram illustrating peak cut power.
【図４】太陽電池の出力特性を説明する図FIG. 4 illustrates output characteristics of a solar cell.
【図５】本発明の第一の実施形態の太陽電池の動作を説
明する図FIG. 5 is a diagram illustrating the operation of the solar cell according to the first embodiment of the present invention.
【図６】本発明の第二の実施形態を示す構成図FIG. 6 is a configuration diagram showing a second embodiment of the present invention.
【図７】本発明の第三の実施形態を示す構成図FIG. 7 is a configuration diagram showing a third embodiment of the present invention.
１…太陽電池、２…切替装置、３…蓄電池、４…電力変
換器、５，５Ａ，５Ｂ…連系装置、６…一般負荷、７…
自立運転負荷、８…系統、９…電流検出器、１０…電圧
検出器、１１…電流検出器、２０…電力検出器、２１…
最大電力追従回路、２２…直流定電圧設定回路、２３…
高電圧選定回路、２４…直流電圧制御回路、２５…外部
電力指令回路、２６…切替器、２７…定電流制御回路、
２８…ゲート回路、２９…タイマー回路、３０…充電ブ
ロック回路、４０…電流検出回路、４１…電圧補正回
路、４２…電圧補正回路、５０…電圧−電圧変換器、５
１…電圧検出器、５２…直流電圧調整回路、５３…電圧
バイアス設定回路DESCRIPTION OF SYMBOLS 1 ... Solar cell, 2 ... Switching device, 3 ... Storage battery, 4 ... Power converter, 5, 5A, 5B ... Interconnection device, 6 ... General load, 7 ...
Autonomous operation load, 8 ... system, 9 ... current detector, 10 ... voltage detector, 11 ... current detector, 20 ... power detector, 21 ...
Maximum power follow-up circuit, 22 ... DC constant voltage setting circuit, 23 ...
High voltage selection circuit, 24 DC voltage control circuit, 25 external power command circuit, 26 switch, 27 constant current control circuit,
28 gate circuit, 29 timer circuit, 30 charging block circuit, 40 current detection circuit, 41 voltage correction circuit, 42 voltage correction circuit, 50 voltage-voltage converter, 5
DESCRIPTION OF SYMBOLS 1 ... Voltage detector, 52 ... DC voltage adjustment circuit, 53 ... Voltage bias setting circuit
Claims (4)
を介して並列に接続された蓄電池と、前記太陽電池の出
力電力を交流電力に変換し、他の交流電源と連系する電
力変換器と、前記太陽電池の出力が増加する方向へ動作
指令を変化させる最大電力追従制御手段と、前記太陽電
池の電圧を一定に制御する直流定電圧制御手段と、外部
からの電力指令による制御を行う手段を備えた太陽光発
電装置であって、前記蓄電池の電圧を前記太陽電池の直
流定電圧より小さい値とするように設定し、前記蓄電池
の電圧が前記太陽電池の電圧よりも小さいときに、前記
蓄電池の放電を阻止することを特徴とするする太陽光発
電装置。1. A solar cell, a storage battery connected in parallel with the solar cell via charging / discharging means, and a power converter for converting output power of the solar cell into AC power and interconnecting with another AC power supply. Device, maximum power follow-up control means for changing the operation command in the direction in which the output of the solar cell increases, DC constant voltage control means for controlling the voltage of the solar cell to be constant, and control by an external power command. A photovoltaic power generation device comprising means for performing, when the voltage of the storage battery is set to a value smaller than the DC constant voltage of the solar cell, when the voltage of the storage battery is smaller than the voltage of the solar cell A solar power generation device for preventing discharge of the storage battery.
供給を行わない場合には、前記太陽電池の最大電力追従
制御または直流定電圧制御を行い、前記蓄電池から電力
供給を行う場合には、前記外部からの電力指令にしたが
って制御を行うことを特徴とするする太陽光発電装置。2. The method according to claim 1, wherein when power is not supplied from the storage battery, maximum power follow-up control or DC constant voltage control of the solar cell is performed, and when power is supplied from the storage battery, A photovoltaic power generator characterized by performing control according to an external power command.
蓄電池に電流検出器を設け、前記最大電力追従制御時あ
るいは前記直流定電圧制御時に前記蓄電池の放電電流を
検出したとき、直流回路電圧の設定値を変更する補正手
段を備えたことを特徴とする太陽光発電装置。3. The battery circuit according to claim 1, wherein a current detector is provided in the storage battery, and when a discharge current of the storage battery is detected during the maximum power follow-up control or the DC constant voltage control, a DC circuit voltage is reduced. A photovoltaic power generator comprising a correction unit for changing a set value.
蓄電池に電流検出器および直流−直流変換器を接続し、
前記電流検出器によって検出された蓄電池出力電圧を直
流回路電圧の設定値より低くするように前記直流−直流
変換器を制御する直流電圧調整手段を備えたことを特徴
とする太陽光発電装置。4. The battery according to claim 1, wherein a current detector and a DC-DC converter are connected to the storage battery.
A photovoltaic power generator, comprising: DC voltage adjusting means for controlling the DC / DC converter so that a storage battery output voltage detected by the current detector is lower than a set value of a DC circuit voltage.
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| Application Number | Priority Date | Filing Date | Title |
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| JP2000214310A JP3656113B2 (en) | 2000-07-14 | 2000-07-14 | Solar power plant |
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| JP2000214310A JP3656113B2 (en) | 2000-07-14 | 2000-07-14 | Solar power plant |
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| Publication Number | Publication Date |
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| JP2002034175A true JP2002034175A (en) | 2002-01-31 |
| JP3656113B2 JP3656113B2 (en) | 2005-06-08 |
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| Application Number | Title | Priority Date | Filing Date |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1986306A1 (en) * | 2006-01-27 | 2008-10-29 | Sharp Kabushiki Kaisha | Power supply system |
| WO2013125425A1 (en) * | 2012-02-22 | 2013-08-29 | シャープ株式会社 | Power conversion device and direct-current system |
| JP2018098952A (en) * | 2016-12-14 | 2018-06-21 | 新電元工業株式会社 | Power storage system and photovoltaic power generation system |
-
2000
- 2000-07-14 JP JP2000214310A patent/JP3656113B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1986306A1 (en) * | 2006-01-27 | 2008-10-29 | Sharp Kabushiki Kaisha | Power supply system |
| EP1986306A4 (en) * | 2006-01-27 | 2012-05-09 | Sharp Kk | Power supply system |
| US8310094B2 (en) | 2006-01-27 | 2012-11-13 | Sharp Kabushiki Kaisha | Power supply system |
| WO2013125425A1 (en) * | 2012-02-22 | 2013-08-29 | シャープ株式会社 | Power conversion device and direct-current system |
| JP2018098952A (en) * | 2016-12-14 | 2018-06-21 | 新電元工業株式会社 | Power storage system and photovoltaic power generation system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3656113B2 (en) | 2005-06-08 |
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