光伏發(fā)電系統(tǒng)外文翻譯文獻

1、文獻信息：文獻標(biāo)題： A NewControllerSchemeforPhotovoltaicsPower GenerationSystems（光伏發(fā)電系統(tǒng)的一種新的控制方案）國外作者：，Azah Mohamed，Nowshad Amin文獻出處： European Journal of ScientificResearch,2009 ，Vol.33 No.3,pp515-524字?jǐn)?shù)統(tǒng)計： 英文 1337 單詞， 7006 字符；中文 2149 漢字外文文獻：A New Controller Scheme for Photovoltaics PowerGeneration SystemsAbs

2、tract :This paper presents a new controller scheme for photovoltaic (PV) power generation systems. The proposed PV controller scheme controls both the boost converter and the battery charger by using a microcontroller in order to extract maximum power from the PV array and control the charging proce

3、ss of the battery.The objective of the paper is to present a cost effective boost converter design and an improved maximum power point tracking algorithm for the PV system. A MATLAB based simulation model of the proposed standalone PV system has been developed to evaluate the feasibility of the syst

4、em in ensuring maximum power point operation.1.IntroductionRecently, the installation of PV generation systems is rapidly growing due to concerns related to environment, global warming, energy security, technology improvements and decreasing costs. PV generation system is considered as a clean and e

5、nvironmentally-friendly source of energy. The main applications of PV systems are in either standalone or grid connected configurations. Standalone PV generationsystems are attractive as indispensable electricity source for remote areas. However, PV generation systems have two major problems which a

6、re related to low conversion efficiency of about 9 to 12 % especially in low irradiation conditions and the amount of electric power generated by PV arrays varies continuously with weather conditions. Therefore, many research works are done to increase the efficiency of the energy produced from the

7、PV arrays.The solar cell V-I characteristics is nonlinear and varies with irradiation and temperature. But there is a unique point on the V-I and P-V curves, called as the maximum power point (MPP), at which at this point the PV system is said to operate with maximum efficiency and produces its maxi

8、mum power output. The location of the MPP is not known but can be traced by either through calculation models or search algorithms. Thus, maximum power point tracking (MPPT) techniques are needed to maintain the PV array s operating point at its MPP. Many MPPT techniques have been proposed in the li

9、terature in which the techniques vary in many aspects, including simplicity, convergence speed, hardware implementation and range of effectiveness. However, the most widely used MPPT technique is the perturbation and observation (P&O) method. This paper presents a simple MPPT algorithm which can be

10、easily implemented and adopted for low cost PV applications. The objective of this paper is to design a novel PV controller scheme with improved MPPT method.The proposed standalone PV controller implementation takes into account mathematical model of each component as well as actual component specif

11、ication. The dcdc or boost converter is the front-end component connected between the PV array and the load. The conventional boost converter may cause serious reverse recovery problem and increase the rating of all devices. As a result, the conversion efficiency is degraded and the electromagnetic

12、interference problem becomes severe under this situation. To increase the conversion efficiency, many modified step-up converter topologies have been investigated by several researchers. oltageV clamped techniques have been incorporated in the converter design to overcome the severe reverse-recovery

13、 problem of the output diodes. In this paper, focus is also given in the boost converter design. Another important component in the standalone PV systemsis the charge controller which is used to save the battery from possible damage due to over-charging and over-discharging. Studies showed that the

14、life time of a battery can be degraded without using a charge controller.The proposed new controller scheme for the standalone PV system controls both the boost converter and the charge controller in two control steps. The first step is to control the boost converter so as to extract the maximum pow

15、er point of the PV modules. Here, a high step-up converter is considered for the purpose of stepping up the PV voltage and consequently reducing the number of series-connected PV modules and to maintain a constant dc bus voltage. A microcontroller is used for data acquisition that gets PV module ope

16、rating current and voltage and is also used to program the MPPT algorithm. The controller adopts the pulse width modulation (PWM) technique to increase the duty cycle of the generated pulses as the PV voltage decreasesso as to obtain a stable output voltage and current close to the maximum power poi

17、nt. The second control step is to control the charge controller for the purpose of protecting the batteries. By controlling the charging current using the PWM technique and controlling the battery voltage during charging, voltages higher than the gassing voltage can be avoided.2.Design of the Propos

18、ed Photovoltaic SystemMost of the standalone PV systems operate in one mode only such that the PV system charges the battery which in turns supply power to the load. In this mode of operation, the life cycle time of the battery may be reduced due to continuous charging and discharging of the battery

19、. The proposed standalone PV system as shown in terms of a block diagram in Figure 1 is designed to operate in two modes: PV system supplies power directly to loads and when the radiation goes down and the produced energy is not enough, the PV system will charge the battery which in turns supply pow

20、er to the load. To manage these modes of operation, a controller is connected to the boost converter by observing the PV output power.3.MethodologyFor the purpose of estimating the mathematical models developed for the proposed standalone PV system, simulations were carried in terms of the MATLAB co

21、des. Each PV module considered in the simulation has a rating of 80 Watt at 1000W/m 2, 21.2 V open circuit voltage, 5A short circuit current. The PV module is connected to a block of batteries with of sizing 60 Ah, 48 V.4.Results and DiscussionThe simulation results of the standalone PV system using

22、 a simple MPPT algorithm and an improved boost converter design are described in this section. Simulations were carried out for the PV system operating above 30o C ambient temperature and under different values of irradiation. Figure 9 shows the PV array I-V characteristic curve at various irradiati

23、on values. From the figure, it is observed that the PV current increase linearly as the irradiation value is increased. However, the PV voltage increases in logarithmic pattern as the irradiation increases. Figure 10 shows the PV array I-V characteristic curve at various temperature values. It is no

24、ted from the figure that, the PV voltage decreases as the ambient temperature is increased.Figure 4 compares the PV array P-V characteristics obtained from using the proposed MPPT algorithm and the classical MPPT P&O algorithm. From this figure, it can be seen that by using the proposed MPPT algorit

25、hm, the operating point of PV array is much closer to the MPP compared to the using the classicalP&O algorithm.In addition, the proposed boost converter is able to give a stable output voltage as shown in Figure 5. In terms of PV array current, it can be seen from Figure 6 that the PV current is clo

26、ser to the MPP current when using the improved MPPT algorithm. Thus, the track operating point is improved by using the proposed MPPT algorithm.In terms of efficiency of the standalone PV system which is calculated by dividing the load power with the maximum power of PV array, it is noted that the e

27、fficiency of the system is better with the proposed MPPT algorithm as compared to using the classical P&O algorithm as shown in Figure 7.5.ConclusionThis paper has presented an efficient standalone PV controller by incorporating an improved boost converter design and a new controller scheme which in

28、corporates both a simple MPPT algorithm and a battery charging algorithm. The simulation results show that the PV controller using the simple MPPT algorithm has provided more power and better efficiency (91%) than the classical P&O algorithm. In addition, the proposed boost converter design gives a

29、better converter efficiency of about 93%. Such a PV controller design can provide efficient and stable power supply for remote mobile applications.中文譯文：光伏發(fā)電系統(tǒng)的一種新的控制方案摘要：本文提出了一種新的光伏（PV）發(fā)電系統(tǒng)控制器方案。所提出的PV控制器方案通過使用微控制器來控制升壓轉(zhuǎn)換器和電池充電器，以便從PV陣列提取最大功率并控制電池的充電過程。本文的目的是提出一種具有成本效益的升壓轉(zhuǎn)換器設(shè)計和用于PV 系統(tǒng)的改進的最大功率點跟蹤算法。已

30、經(jīng)開發(fā)了基于MATLAB的獨立光伏系統(tǒng)的仿真模型，以評估系統(tǒng)在確保最大功率點操作的可行性。引言最近，由于環(huán)境、全球變暖、能源安全、技術(shù)改進和降低成本有關(guān)的問題，PV發(fā)電系統(tǒng)的安裝正在快速增長。 光伏發(fā)電系統(tǒng)被認為是一種清潔環(huán)保的能源。光伏系統(tǒng)的主要應(yīng)用是獨立或并網(wǎng)配置。 獨立的光伏發(fā)電系統(tǒng)作為偏遠地區(qū)不可或缺的電源是有吸引力的。然而， PV 發(fā)電系統(tǒng)具有兩個主要問題，其涉及約 9至 12的低轉(zhuǎn)換效率，特別是在低照射條件下，并且由 PV陣列產(chǎn)生的電功率的量隨天氣條件連續(xù)變化。因此，進行了許多研究工作以增加從 PV陣列產(chǎn)生的能量的效率。太陽能電池V-I 特性是非線性的，隨著輻射和溫度而變化。但是在

31、V-I 和P-V 曲線上有一個獨特的點，稱為最大功率點（MPP），在該點 PV 系統(tǒng)被稱為以最大效率運行并產(chǎn)生其最大功率輸出。MPP的位置是未知的，但可以通過計算模型或搜索算法來跟蹤。因此，需要最大功率點跟蹤（MPPT）技術(shù)來將 PV陣列的工作點維持在其MPP。在文獻中已經(jīng)提出了許多MPPT技術(shù)，其中技術(shù)在許多方面各有不同，包括簡單性、收斂速度、硬件實現(xiàn)和有效范圍。然而，最廣泛使用的 MPPT技術(shù)是擾動和觀察（ P O）方法。本文提出了一個簡單的 MPPT算法，可以輕松實現(xiàn)和采用低成本光伏應(yīng)用。本文的目的是設(shè)計一種改進的 MPPT方法的新型 PV控制器方案。提出的獨立光伏控制器考慮到實現(xiàn)數(shù)學(xué)模

32、型每個組件以及實際的組件規(guī)范。DC-DC或升壓轉(zhuǎn)換器是連接在PV 陣列和負載之間的前端組件。傳統(tǒng)的升壓轉(zhuǎn)換器可能導(dǎo)致嚴(yán)重的反向恢復(fù)問題， 并增加所有器件的額定值。 因此，在這種情況下，轉(zhuǎn)換效率降低，并且電磁干擾問題變得嚴(yán)重。為了提高轉(zhuǎn)換效率，若干研究人員對許多改進的升壓轉(zhuǎn)換器拓撲結(jié)構(gòu)進行了研究。 電壓鉗位技術(shù)已被納入轉(zhuǎn)換器的設(shè)計，以克服輸出二極管的嚴(yán)重反向恢復(fù)問題。 在本文中， 重點也是給出升壓轉(zhuǎn)換器設(shè)計。 獨立光伏系統(tǒng)的另一個重要組件是充電控制器， 用于避免電池由于過多充電和過多放電而可能造成的損壞。 研究表明，在不使用充電控制器的情況下，電池的壽命可能會下降。所提出的用于獨立光伏系統(tǒng)的新控制器方案在兩個控制步驟中控制升壓轉(zhuǎn)換器和充電控制器。第一步是控制升壓轉(zhuǎn)換器，以提取光伏組件的最大功率點。在這里，高升壓型轉(zhuǎn)換器被認為是對加強光伏電壓起作用， 從而降低了串聯(lián)光伏組件的數(shù)量，并保持一個恒定的直流總線電壓的目的。微控制器用于獲取 PV組件工作電流和電壓的數(shù)據(jù)采集，也用于對 MPPT算法進行編程?？刂破鞑捎妹}沖寬度調(diào)制（ PWM）技術(shù)以隨著 PV電壓降低而增加所產(chǎn)生的脈沖的占空比， 以便獲得接近最大功率點的穩(wěn)定的輸出電壓和電流。 第二控制步驟是為了保護電池而控制