Weak current College】 【battery capacity design.

<br> <br> <br> Solar power systems and energy storage device mainly battery. And solar cell matrix matching battery usually work in floating State, its voltage with electricity generation capacity and load the Phalanx. It is loads the desired power. Battery .for energy is also affected by ambient temperature. In order to match with the solar cell, battery operating life long and easy maintenance. <br> <br> (1) selection of battery <br> <br> To and supporting the use of .solar energy battery for battery types, there are currently widely used lead-acid battery, ordinary alkaline batteries and nickel-cadmium batteries. Domestic main use lead-acid battery, because of its inherent characteristics of the "free" maintenance and environmentally cleaner features, .very suitable for reliable solar power system, especially the unattended workstation. Common lead-acid batteries due to the need for regular maintenance and environmental pollution is large, so mainly for maintenance or low quality. Alkaline nickel-cadmium batteries, although good low-temperature ., charge, over discharge performance, but because of their higher prices, only applies to more special occasions. <br> <br> (2) the calculation of the battery capacity <br> <br> Battery capacity to ensure continuous power supply is .very important. Within one year, square of the generating capacity varies significantly. Phalanx of generating capacity in does not meet the electricity needs of the month, should depend on battery power to to fill in more than a month of electricity needs, rely on battery .power would be redundant storage. So enough of the square matrix generation capacity and surplus value that is the basis for determining the battery capacity. Similarly, the continuous wet weather during load power must also be obtained from the battery. Therefore, the power consumption of .this period is also the determining factor in battery capacity. <br> <br> Therefore, the battery capacity is calculated as: BC BC = A × QL × NL × TO / CCAh (1) type: A-safety factor, 1.1 ~ .1.4; QL to load average electricity consumption, as the operating current multiplied by the number of daily work hours; NL for the longest consecutive rainy days; TO <br> <br> A temperature correction factor, generally take 1 0 º c, 10 ° .c above take-1.1, -10 ℃ below take 1.2; <br> <br> CC-battery discharge depth, generally take lead-acid batteries, alkaline nickel-cadmium batteries 0.75 take 0.85. <br> <br> 2. solar .array design <br> <br> (1) solar module in series number Ns <br> <br> Solar module series by a certain number, you can obtain the required operating voltage, however, the solar module series number must be appropriate. .-Too few series voltage below the floating charge voltage of battery, the matrix will not be able to recharge the battery. If the serial number too much output voltage well above the floating charge voltage, charge current will not increase significantly. Therefore, only when .the solar module in series voltage is equal to the right floating charge voltage, in order to achieve the best charging status. <br> <br> Calculated as follows: Ns = UR / Uoc = (Uf + UD + Uc) / Uoc ( .2) type: UR-solar array output minimum voltage Uoc-solar module best operating voltage; Uf is a floating charge voltage of battery; the pressure drop for diode UD, generally take 0.7V; UC as other factor caused by pressure drop. < .br> <br> City Latitude Φ, radiation Ht best angle Φ op bevel, radiation correction factor Kop <br> <br> Harbin 45.6812703 Φ + 3158381.1400 <br> <br> Changchun 43.9013572 Φ + 1171271.1548 <br> <br> Shenyang .41.7713793 Φ + 1165631.0671 <br> <br> Beijing 39.8015261 Φ + 4180351.0976 <br> <br> (2) solar module parallel number Np4 <br> <br> Before determining the NP, we first determine the relevant calculation methods. <br .> <br> ① the solar array installation site of the solar energy, radiation Ht, converted to the standard light intensity of the average daily radiation hours H (daily radiation levels see table 1): H = Ht × 2.778/10000h (3) .type: 2.778/10000 (kJ · m2 / h) for the Japan radiation intensity for the standard (1000W/m2) of the average daily number of coefficients of radiation. <br> <br> ② solar module, power generation QpQp = Ioc .× H × Kop × CzAh (4) type: Ioc for solar module best current; Kop as bevel correction coefficient (see table 1); Cz for correction factors, mainly to grouped, attenuation, dust, charging efficiency losses, generally take 0.8. .<br> <br> ③ two groups of maximum continuous rainy days the shortest interval between days Nw, this data-oriented design of unique, primary consideration to the time of the loss, battery charge added complemented by Bcb for battery capacity: Bcb = .A × QL × NLAh (5) <br> <br> ④ solar module parallel calculation of number of Np: Np = (Bcb + Nw × QL) / (Qp × Nw) (6) - (6) of the expression means .: consisting of the number of solar battery group, in the two groups of continuous rain days between the shortest interval in days, not only within the electricity use for workloads, also need to make up the battery in the longest consecutive rainy days the loss of .power. <br> <br> (3) solar array power calculation <br> <br> According to the solar module in series and parallel number, you can draw the desired solar array power P: P = Po × Ns × NpW ( .7) type: Po for solar module power rating. <br> <br> Design example 3 <br> <br> A ground-based satellite receiving station, for example, load power voltage of 12 v, As 25W daily 24h, the .longest consecutive rainy days the longest 15d, two consecutive rainy days the shortest interval days 30d, solar cells with Yunnan semiconductor device factory 38D975 × 400 components, component standard power to 38W, operating voltage 17.1V, current use of lead-acid battery 2.22A ., maintenance-free battery, floating charge voltage (14 ± 1) V. Its level of solar radiation data reference table 1, the level of the average daily radiation 12110 (kJ/m2), Kop 0.885, the optimum angle 16.13 °, calculation .of solar array power and battery capacity. 5 <br> <br> (1) the battery capacity A × QL × NL × To / BcBc = CC = 1.2 × (25/12) × 24 × 15 × 1/0.75 = 1200Ah .<br> <br> (2) solar array rate P because: Ns = UR / Uoc = (Uf + UD + UC) / Uoc = (14 + 0.7 +) / 17.1 = 0.92 ≈ 1Qp = Ioc × H × Kop × .Cz = 2.22 × 12110 × (2.778/10000) × 0.885 × 0.8 ≈ 5.29AhBcb = A × QL × NL = 1.2 × (25/12) × 24 × 15 = 900AhQL = (25/12) * 24 = 50Ah <br .> <br> Np = (Bcb + Nw × QL) / (Qp × Nw) = (900 +30 × 50) / (5.29 × 30) ≈ 15 <br> <br> The solar array to power: P = Po × Ns × Np .= 38 × 1 × 15 = 570W <br>.