【導(dǎo)讀】太陽能源是一種最有前途的可再生能源。太陽跟蹤器可以大幅度提高。本文提出了一種新穎的利用的雙軸太陽跟蹤光伏系統(tǒng)的設(shè)計反饋控制理論以及。四象限光電阻傳感器和簡單的電子電路提供強健的系統(tǒng)性能。擬議的系統(tǒng)采用獨特的。雙軸交流電機和一個獨立的光伏逆變器完成太陽能跟蹤。控制執(zhí)行是一種簡單而有效的技。此外構(gòu)造了一個按比例縮小的實驗室原型來驗證該計劃的可行性。了太陽跟蹤器的有效性。最后，本研究結(jié)果可以作為未來太陽能應(yīng)用的參考。光伏面板或模塊是光伏電池封裝互連的大會。相對于固定效應(yīng)的面板，由太陽跟蹤器驅(qū)。要實現(xiàn)較高程度的跟蹤精。這類系統(tǒng)總是涉及使用微處理器芯片作為控制平臺的復(fù)雜跟蹤策略。在這項工作，只有單。陽光跟蹤被允許在他們各自的范圍內(nèi)同時移動。此外，擬議的制度使用獨立的光伏逆變器驅(qū)動電機，并提供電源。發(fā)達國家的太陽跟蹤器由三個模塊，是組成LDR. LDR時，將降低電壓分壓器的輸出電壓蒙上了陰影。如果西方LDR是灰色，

　　

【正文】 . Comparator The main function of the parator is to act as a switch to turn on the relay and rotate the motor. A parator is essentially an operational amplifier (opamp) operated in an openloop configuration, which converts a timevarying analog signal into a binary output. As depicted in the second part of Figure 4, the parator is designed to pare the error voltage with two threshold values. The threshold value is defined as the input voltage at which the output changes states. As shown in Figure 4, there are two threshold values which are given as: The output of the parator is a high saturated state VH or a low saturated state VL. The saturated output voltages VH and VL may be closed to the supply voltages +VCC and ?VCC, respectively. The parator outputs are then expressed as follows: The voltage transfer characteristics of the parator with ideal opamps are shown in Figure 6. It is noted that the sensitivity for the tracking system is dominated by the threshold values, which are adjusted by the variable resistor R4 according to the tracking accuracy. As R4 decreases, the tracking accuracy increases. However, the system tracking response will bee increasingly oscillatory. Figure 6. Voltage transfer characteristics of the openloop parator. . Motor Driver with a Relay As seen in the last part of Figure 4, it is observed that the designed motor driver with a relay consists of two Darlington pairs that provide increased current gain and actuate the relay. If the west LDR is shaded, a feedback error voltage vEW is generated. When vEW VTh1 VTh2, the parator outputs vPE and vPW go high and low saturated voltages respectively. The transistors Q1 and Q2 will therefore conduct and Q3 and Q4 are in the cutoff state. Referring to Figure 4, transistors Q1 and Q2 operate in the forwardactive mode, and the input current or the base current of Q1 is: where VBE is the forwardbiased baseemitter voltage of the bipolar transistor. Therefore, the output current can be written as: The parameters 1β and 2 β are the monemitter current gain of the bipolar transistors. The relay is activated by the output current and normallyopen contact a1 closes. In this case, the tracking motor rotates clockwise in the azimuth direction and thus the PV panel moves eastward to face the Sun. More specifically, the Sun tracker attempts to adjust the PV panel such that all the voltages produced by LDRs are nearly equal and balance. As a result, the PV panel is almost perpendicular to the sunlight and has a high energy generation. The paper has presented a novel and a simple control implementation of a Sun tracker that employed a single dualaxis AC motor to follow the Sun and used a standalone PV inverter to power the entire system. The proposed onemotor design was simple and selfcontained, and did not require programming and a puter interface. A laboratory prototype has been successfully built and tested to verify the effectiveness of the control implementation. Experiment results indicated that the developed system increased the energy gain up to % for a partly cloudy day. The proposed methodology is an innovation so far. It achieves the following attractive features: (1) a simple and costeffective control implementation, (2) a standalone PV inverter to power the entire system, (3) ability to move the two axes simultaneously within their respective ranges, (4) ability to adjust the tracking accuracy, and (5) applicable to moving platforms with the Sun tracker. Theempirical findings lead us to believe that the research work may provide some contributions to the development of solar energy applications.