201145763 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種將太陽電池予以串聯而成之太陽能 發電裝置及太陽能發電系統。 【先前技術】 太陽能發電裝置係將太陽能轉換成電能，作為不產生 co2之潔淨能源已受到重視。 由於太陽電池之每一單位元件（太陽電池元件）之產生 電壓係低至IV以下’因此將串聯有複數個太陽電池元件之 區塊再加以串並聯。 若串聯之太陽電池元件的一部分被陰影遮蔽，則不僅 該太陽電池元件無法發電，而且亦會變成高阻抗。此時， 所有串聯之太陽電池元件之發電能量的回收效率便會降 低。 因此，對太陽電池元件（單一元件）或數個元件並聯二極 體，使發電能量繞過變成高阻抗之太陽電池元件，以改善 整體之發電能量的回收效率。 圖4係表示習知之太陽能發電裝置之一例的電路構成 圖（專利文獻1)。圖4所示之太陽能發電裝置，係藉由串聯 有3個太陽電池元件1的串聯電路、以及並聯於該串聯電 路之兩端的二極體2(旁通二極體）而構成太陽電池區塊3。 將該太陽電池區塊3予以串聯所構成之太陽能發電裝 置4，係對負載5供應電力。負載5係藉由蓄電池或系統連 201145763 接變流器等所構成’以蓄積所發電之能量或再生革交流系 統。 又，如圖5所示，亦可透過二極體6— 1〜6— η將太陽 能發電裝置4 一 1〜4 — η並聯於負載5，藉此獲得較圖4所 示之太陽能發電裝置更高的輸出。 專利文獻1 :日本特開昭56 — 69871號公報 【發明内容】 然而，將二極體2並聯於3個太陽電池元件1之串聯 電路的圖4所示之太陽能發電裝置中，因二極體2之麼降 所產成之發熱較大，而該發熱則會使系統整體之效率降低。 又’並聯太陽能發電裝置4一 1〜4—η之圖5所示之太 陽能發電裝置中’會因二極體2旁通之數而在各太陽能發 電裝置之發電電壓產生不均。 此時’會因產生最大發電電壓之太陽能發電裝置，而 使最小發電電壓之太陽能發電裝置的輸出電力降低，導致 太陽能發電系統整體之發電效率降低。 本發明係在於提供一種可降低因旁通二極體所造成之 損失、並且提升系統整體的發電效率之太陽能發電裝置及 太陽能發電系統。 為了解決前述課題，申請專利範圍第1項之發明，其 特徵係在於：將由串聯之1個以上之太陽電池元件、以及 並聯於該i個以上之太陽電池元件並且在太陽光照射時斷 開且在該太陽光未照射時導通之半導體開關所構成的複合 4 201145763 元件予以串聯複數個而成。 根據本發明，由於並聯於1個以上之太陽電池元件的 半導體開關係在太陽光照射時斷開，而在太陽光未照射時 導通’因此半導體開關之導通電壓其壓降係小於旁通二極 體之順向電壓Vf，所以可降低繞過1個以上之太陽電池元 件時的損失。 【實施方式】 以下’一邊參照圖式一邊詳細地說明本發明之太陽能 發電裝置及太陽能發電系統的實施形態。 [實施例1 ] 圖1係表示實施例1之太陽能發電裝置的電路構成 圖。圖1所示之實施例1之太陽能發電裝置4a，係藉由串 聯有3個太陽電池元件1之串聯電路、在該串聯電路之兩 端連接有汲極一源極的半導體開關7、以及連接於半導體開 關7之閘極—源極之間的太陽電池元件la構成太陽電池區 塊3a ’再串聯複數個太陽電池區塊3a所構成。 半導體開關7係由氮化鎵（GaN)、碳化矽（SiC)等之由寬 能隙半導體（wideband gap semiconductor)構成之常態導通 (normally on)型之開關所構成，在太陽光照射時斷開而在太 1%光未照射時導通。 此外，亦可使用GaN之高電子移動性電晶體（HEMT : High Electron Mobility Transistor)，以取代 GaN、SiC 等之 寬能隙半導體。 5 201145763 其次，說明以此方式構成之實施例1之太陽能發電裝 置的動作。由於在太陽光未照射到太陽電池元件1時，於 太陽電池元件1不會產生電壓，半導體開關7之閘極一源 極間約為零，因此半導體開關7係導通。 另—方面’由於在太陽光照射到太陽電池元件1時， 於半導體開關7之閘極一源極間施加有陰極電壓，因此半 導體開關7則變成斷開。因此，會輸出太陽電池元件i之 發電電力。 以此方式，根據實施例1之太陽能發電裝置，由於半 導體開關7係在太陽光照射時斷開，在太陽光未照射時導 通’因此如圖2所示，由於半導體開關7之導通電壓v〇n7 其壓降係小於旁通二極體2之順向電壓Vf2，所以可降低繞 過1個以上之太陽電池元件1時的損失。 又’為了使半導體開關7斷開’只要將閘極電壓設為 負電位，並不產生閘極驅動損失，而不會降低太陽能發電 時之效率。 亦即，相較於使用二極體2之習知太陽能發電裝置， 由於半導體開關7所形成之旁通電路的阻抗較小，因此即 使太陽電池元件丨因陰影等被遮蔽時，對太陽能發電系統 整體所造成之影響亦較少。 [實施例2] 圖 圖3係表不實施例2之太陽能發電系統的電路構成 圖3所示之太陽能發電系統，係藉由透過二極體 6—4將太陽能發電裝置4a — 4a—4並聯於負載5所構 ⑧ 201145763 成。此外’太陽能發電裝置之並聯數並非限制於4個。 各太陽能發電裝置4a— 1〜4a— 4，係藉由串聯有3個 太陽電池元件1之串聯電路、在該串聯電路之兩端連接有 沒極一源極的半導體開關7、以及連接於半導體開關7之間 極一源極之間的太陽電池元件la構成太陽電池區塊h —夏 〜3a—4’再串聯複數個太陽電池區塊3a_i〜3 *所構 成。 於各太陽能發電裝置4a— 1〜4a—4，係串聯有電流檢 測電阻8 — 1〜8 — 4(檢測部）。以電流檢測電阻8 — 1〜8 __ 4 檢測出之電流訊號，係輸入至控制電路1〇。 此外’亦可檢測太陽能發電裝置4a— 1〜4a- 4之電 壓’以取代檢測流至太陽能發電裝置4a— 1〜4a— 4之電流。 實施例2中’最接近於控制電路1〇之太陽電池區塊3a 了 1〜3 a — 4内之半導體開關7 — 1〜7 — 4的閘極與源極係連 接於控制電路1 〇。 控制電路1 〇 ’係比較從複數個電流檢測電阻8 — 1〜8 一 4輸入之複數個電流，再根據複數個電流值，將控制訊號 施加於太陽能發電裝置内之半導體開關7的閘極一源極之 間’其中該太陽能發電裝置係對應複數個電流值内之除了 最小電流值以外的其餘電流值，藉此使該半導體開關7導 通。 或者’控制電路1 〇，係輸入並比較太陽能發電裝置4a —1〜4a—4之電壓，再根據複數個電壓值，將控制訊號施 加於太陽能發電裝置内之半導體開關7的閘極—源極之 201145763 間’其中S亥太陽能發電裝置係對應複數個電壓值内之除了 最小電壓值以外的其餘電壓值，藉此使使該半導體開關7 導通。 其次’說明以此方式構成之實施例2之太陽能發電系 統的動作。 首先’藉由複數個電流檢測電阻8 _ 1〜8 — 4，檢測流 至複數個太陽能發電裝置4a — 1〜4a — 4之電流，該等電流 係輸入至控制電路1 〇。 控制電路10係根據來自複數個電流檢測電阻8 _ 1〜8 —4之複數個電流值，將控制訊號施加於太陽能發電裝置 3a— 2〜3a— 4内之半導體開關7— 2〜7— 4的閘極一源極之 間’其中§玄太陽能發電裝置3 a — 2〜3 a — 4係對應複數個電 流值内之除了最小電流值、例如流經電流檢測電阻8 — 1之 最小電流值以外的其餘各電流值，藉此使閘極與源極之間 約為零’以使該半導體開關7- 2〜7— 4導通。因此，太陽 能發電裝置3a- 2〜3a— 4之電壓便會接近而與太陽能發電 裝置3a—1之電壓一致。 亦即，比較各太陽能發電裝置4a — 1〜4a — 4之發電 量’將發電量較多之太陽能發電裝置之一部分的太陽電池 區塊予以短路，以使端子電壓降低。藉由使太陽能發電裝 置之端子電壓降低，使各線電壓一致而獲得來自發電電壓 較低之太陽能發電裝置的發電量，藉此即使減掉發電電壓 較低之太陽能發電裝置以外之發電量的降低部分，在超過 來自發電電壓較低之太陽能發電裝置之線之發電量的條件 ⑧ 201145763 下，使半導體開關7導通，藉此即可提升太陽能發電系統 整體的發電效率。 此外，本發明並非限定於實施例1及實施例2之太陽 月b發電裝置及太陽能發電系統。例如，亦可在半導體開關7 之閘極與源極之間插入電容器或電阻，以調整對半導體開 關7之導通/斷開之時間常數或閾值。 本發明可應用於畜電池、及變流器（inverter)等。 【圖式簡單說明】 圆1係表示實施例1之太陽能發電裝置的電路構成圖。 圖2係表示實施例1之太陽能發電裝置之半導體開關 的特性與習知之二極體的特性。 圖3係表示實施例2之太陽能發電系統的電路構成圖。 圖4係表示習知之太陽能發電裝置之一例的電路構成 圖。 圖5係表示習知之太陽能發電系統之另一例的番狄 ^ j π電路構 【主要元件符號說明】 1，1 a :太陽電池元件 2 :二極體 3，3a, 3a — 1〜3a—4 :太陽電池區塊 4, 4a，4 — i〜4 — η :太陽能發電裝置 5 :負載 9 201145763 6 _ 1〜6 — η :二極體 7,7— 1〜7—4:常態導通型之開關 8 — 1〜8 — 4 :電流檢測電阻 1 0 :控制電路 10 ⑧201145763 VI. Description of the Invention: [Technical Field] The present invention relates to a solar power generation device and a solar power generation system in which solar cells are connected in series. [Prior Art] A solar power generation device converts solar energy into electric energy, and has been paid attention as a clean energy source that does not generate co2. Since the voltage generated by each unit element (solar cell element) of the solar cell is as low as IV or less, the blocks in which a plurality of solar cell elements are connected in series are connected in series and in parallel. If a part of the solar cell elements connected in series is shaded, not only the solar cell element cannot generate electricity, but also becomes high impedance. At this time, the recovery efficiency of the power generation energy of all the solar cell elements connected in series is lowered. Therefore, the solar cell element (single element) or a plurality of elements are connected in parallel with the diode, so that the power generation energy is bypassed to become a high-impedance solar cell element, thereby improving the recovery efficiency of the overall power generation energy. Fig. 4 is a circuit configuration diagram showing an example of a conventional solar power generation device (Patent Document 1). The solar power generation device shown in FIG. 4 is constituted by a series circuit in which three solar cell elements 1 are connected in series, and a diode 2 (bypass diode) connected in parallel to both ends of the series circuit to constitute a solar cell block. 3. The solar power generation device 4 configured by connecting the solar battery blocks 3 in series supplies electric power to the load 5. The load 5 is composed of a battery or a system connected to a 201145763 inverter or the like to accumulate energy generated by the accumulation or a regenerative leather communication system. Moreover, as shown in FIG. 5, the solar power generation device 4-1~4-n can also be connected to the load 5 through the diodes 6-1 to 6-n, thereby obtaining a solar power generation device more than that shown in FIG. High output. Patent Document 1: Japanese Laid-Open Patent Publication No. SHO 56-69871. SUMMARY OF THE INVENTION However, the diode 2 is connected in parallel to the solar power generation device shown in FIG. 4 of the series circuit of three solar cell elements 1, because of the diode. The heat generated by the 2nd drop is greater, and the heat will reduce the overall efficiency of the system. Further, in the solar power generation device shown in Fig. 5 of the parallel solar power generation device 4 - 1 to 4 - η, the power generation voltage of each solar power generation device is uneven due to the number of bypasses of the diode 2. At this time, the output power of the solar power generation device having the minimum power generation voltage is lowered by the solar power generation device that generates the maximum power generation voltage, and the power generation efficiency of the entire solar power generation system is lowered. The present invention is to provide a solar power generation device and a solar power generation system which can reduce the loss due to the bypass diode and improve the power generation efficiency of the entire system. In order to solve the above problems, the invention of claim 1 is characterized in that one or more solar cell elements connected in series are connected to the one or more solar cell elements in parallel and are turned off during sunlight irradiation. The composite 4 201145763 component composed of a semiconductor switch that is turned on when the sunlight is not irradiated is connected in series. According to the present invention, since the semiconductor-on relationship in parallel with one or more solar cell elements is turned off when the sunlight is irradiated, and turned on when the sunlight is not irradiated, the on-voltage of the semiconductor switch is lower than the bypass dipole. Since the forward voltage Vf of the body is reduced, the loss when bypassing one or more solar cell elements can be reduced. [Embodiment] Hereinafter, embodiments of a solar power generation device and a solar power generation system according to the present invention will be described in detail with reference to the drawings. [Embodiment 1] Fig. 1 is a circuit configuration diagram showing a solar power generation device of Embodiment 1. The solar power generation device 4a of the first embodiment shown in FIG. 1 is a series circuit in which three solar cell elements 1 are connected in series, a semiconductor switch 7 having a drain-source connected to both ends of the series circuit, and a connection The solar cell element 1a between the gate and the source of the semiconductor switch 7 constitutes a solar cell block 3a' and is further connected in series with a plurality of solar cell blocks 3a. The semiconductor switch 7 is composed of a normally on-type switch composed of a wide band gap semiconductor such as gallium nitride (GaN) or tantalum carbide (SiC), and is disconnected when irradiated with sunlight. It is turned on when too much light is not irradiated. Further, a GaN high electron mobility transistor (HEMT) may be used instead of a wide band gap semiconductor such as GaN or SiC. 5 201145763 Next, the operation of the solar power generating apparatus of the first embodiment configured in this manner will be described. When the solar cell element 1 is not irradiated with sunlight, no voltage is generated in the solar cell element 1, and the gate and the source of the semiconductor switch 7 are approximately zero, so that the semiconductor switch 7 is turned on. On the other hand, since the cathode voltage is applied between the gate and the source of the semiconductor switch 7 when sunlight is applied to the solar cell element 1, the semiconductor switch 7 is turned off. Therefore, the generated electric power of the solar cell element i is output. In this way, according to the solar power generating apparatus of the first embodiment, since the semiconductor switch 7 is turned off when the sunlight is irradiated and turned on when the sunlight is not irradiated, the turn-on voltage v 半导体 of the semiconductor switch 7 is shown in FIG. The voltage drop of n7 is smaller than the forward voltage Vf2 of the bypass diode 2, so that the loss when one or more solar cell elements 1 are bypassed can be reduced. Further, in order to turn off the semiconductor switch 7, the gate voltage is set to a negative potential, and gate drive loss is not generated, and the efficiency at the time of solar power generation is not lowered. That is, compared with the conventional solar power generation device using the diode 2, since the impedance of the bypass circuit formed by the semiconductor switch 7 is small, even if the solar cell element is shielded by a shadow or the like, the solar power generation system is The overall impact is also less. [Embodiment 2] Fig. 3 is a circuit diagram showing the solar power generation system of the second embodiment. The solar power generation system shown in Fig. 3 is connected in parallel by the solar power generation devices 4a-4a-4 through the diodes 6-4. In the load 5 constructed 8 201145763 into. In addition, the number of parallel connections of solar power generation devices is not limited to four. Each of the solar power generation devices 4a-1 to 4a-4 is connected to the semiconductor by a series circuit in which three solar cell elements 1 are connected in series, a semiconductor switch 7 having a sourceless electrode connected to both ends of the series circuit, and a semiconductor The solar cell element 1a between the pole and the source between the switches 7 constitutes a solar cell block h-summer~3a-4' and is further connected in series with a plurality of solar cell blocks 3a_i~3*. In each of the solar power generation devices 4a-1 to 4a-4, current detecting resistors 8-1 to 8-4 (detection portions) are connected in series. The current signal detected by the current detecting resistors 8 - 1 to 8 __ 4 is input to the control circuit 1 . Further, the voltage of the solar power generating devices 4a-1 to 4a-4 can be detected instead of detecting the current flowing to the solar power generating devices 4a-1 to 4a-4. In the solar cell block 3a of the second embodiment, which is closest to the control circuit 1a, the gates and source terminals of the semiconductor switches 7-1 to 7-4 in 1 to 3a-4 are connected to the control circuit 1A. The control circuit 1 比较' compares a plurality of currents input from the plurality of current detecting resistors 8 - 1 to 8 - 4, and applies a control signal to the gate of the semiconductor switch 7 in the solar power generating device according to the plurality of current values. Between the sources, the solar power generation device corresponds to a current value other than the minimum current value among the plurality of current values, thereby turning on the semiconductor switch 7. Or 'control circuit 1', input and compare the voltages of the solar power generating devices 4a-1 to 4a-4, and then apply control signals to the gate-source of the semiconductor switch 7 in the solar power generating device according to the plurality of voltage values. In the case of 201145763, the Shai solar power generation device corresponds to a voltage value other than the minimum voltage value among the plurality of voltage values, thereby turning on the semiconductor switch 7. Next, the operation of the solar power generation system of the second embodiment constructed in this manner will be described. First, the current flowing to the plurality of solar power generating devices 4a-1 to 4a-4 is detected by a plurality of current detecting resistors 8_1 to 8-4, and the currents are input to the control circuit 1A. The control circuit 10 applies a control signal to the semiconductor switches 7-2 to 7-4 in the solar power generating devices 3a-2 to 3a-4 according to a plurality of current values from the plurality of current detecting resistors 8_1 to 8-4. Between the gate and the source of the gate, the θ 太阳能 solar power generation device 3 a — 2 〜 3 a — 4 corresponds to a minimum current value in a plurality of current values, for example, a minimum current value flowing through the current detecting resistor 8.1 The remaining current values other than this, thereby causing the gate to the source to be approximately zero 'to turn the semiconductor switches 7-2 to 7-4 on. Therefore, the voltages of the solar power generation devices 3a - 2 to 3a - 4 are close to each other and match the voltage of the solar power generation device 3a - 1 . That is, the amount of power generation of each of the solar power generation devices 4a-1 to 4a-4 is compared. The solar cell block of one of the solar power generation devices having a large amount of power generation is short-circuited to lower the terminal voltage. By reducing the terminal voltage of the solar power generation device and making the respective line voltages uniform, the amount of power generation from the solar power generation device having a low power generation voltage is obtained, thereby reducing the amount of power generation other than the solar power generation device having a low power generation voltage. The semiconductor switch 7 is turned on under the condition 8 201145763 which exceeds the power generation amount from the line of the solar power generation device having a low power generation voltage, thereby improving the power generation efficiency of the entire solar power generation system. Further, the present invention is not limited to the solar moon b power generation device and the solar power generation system of the first embodiment and the second embodiment. For example, a capacitor or resistor may be inserted between the gate and the source of the semiconductor switch 7 to adjust the time constant or threshold for turning on/off the semiconductor switch 7. The present invention can be applied to a livestock battery, an inverter, and the like. BRIEF DESCRIPTION OF THE DRAWINGS A circle 1 is a circuit configuration diagram of a solar power generation device of the first embodiment. Fig. 2 is a view showing characteristics of a semiconductor switch of the solar power generating apparatus of the first embodiment and characteristics of a conventional diode. Fig. 3 is a circuit configuration diagram showing a solar power generation system of the second embodiment. Fig. 4 is a circuit configuration diagram showing an example of a conventional solar power generating apparatus. Fig. 5 is a view showing a circuit diagram of another example of a conventional solar power generation system [main element symbol description] 1, 1 a: solar battery element 2: diode 3, 3a, 3a - 1 to 3a - 4 : Solar cell block 4, 4a, 4 — i~4 — η : Solar power generation device 5 : Load 9 201145763 6 _ 1~6 — η : Diode 7,7—1~7—4: Normal conduction type Switch 8 - 1 to 8 - 4 : Current detecting resistor 1 0 : Control circuit 10 8