/// <summary>直散分離を行い、法線面直達日射量と水平面全天日射量を推定する</summary>
/// <param name="method">直散分離の手法</param>
/// <param name="globalHorizontalRadiation">水平面全天日射量[W/m2]</param>
public void EstimateDiffuseAndDirectNormalRadiation(double globalHorizontalRadiation,
DiffuseAndDirectNormalRadiationEstimatingMethod method)
{
this.GlobalHorizontalRadiation = globalHorizontalRadiation;
EstimateDiffuseAndDirectNormalRadiation(globalHorizontalRadiation,
this.Latitude, this.Longitude, this.StandardLongitude,
this.CurrentDateTime, method, out this.directNormalRadiation, out this.diffuseHorizontalRadiation);
}
/// <summary>水平面全天日射量[W/m2]をもとに直散分離を行う</summary>
/// <param name="globalHorizontalRadiation">水平面全天日射量[W/m2]</param>
/// <param name="latitude">緯度[degree]</param>
/// <param name="xlongitude">計算地点の経度[degree]</param>
/// <param name="sLongitude">標準時を規定する地点の経度（東経で正）[degree]</param>
/// <param name="dTime">日時</param>
/// <param name="method">直散分離の手法</param>
/// <param name="directSolarRadiation">法線面直達日射量[W/m2]</param>
/// <param name="diffuseHorizontalRadiation">天空日射[W/m2]</param>
public static void EstimateDiffuseAndDirectNormalRadiation(
double globalHorizontalRadiation,
double latitude, double xlongitude, double sLongitude, DateTime dTime,
DiffuseAndDirectNormalRadiationEstimatingMethod method,
out double directSolarRadiation, out double diffuseHorizontalRadiation)
{
estimateDiffuseAndDirectNormalRadiation(globalHorizontalRadiation, latitude, xlongitude, sLongitude, dTime,
method, out directSolarRadiation, out diffuseHorizontalRadiation);
}
/// <summary>水平面全天日射量[W/m2]をもとに直散分離を行う</summary>
/// <param name="globalHorizontalRadiation">水平面全天日射量[W/m2]</param>
/// <param name="latitude">緯度[degree]</param>
/// <param name="xlongitude">計算地点の経度[degree]</param>
/// <param name="sLongitude">標準時を規定する地点の経度（東経で正）[degree]</param>
/// <param name="dTime">日時</param>
/// <param name="directSolarRadiation">法線面直達日射量[W/m2]</param>
/// <param name="method">直散分離の手法</param>
/// <param name="diffuseHorizontalRadiation">天空日射[W/m2]</param>
private static void estimateDiffuseAndDirectNormalRadiation(
double globalHorizontalRadiation,
double latitude, double xlongitude, double sLongitude, DateTime dTime,
DiffuseAndDirectNormalRadiationEstimatingMethod method,
out double directSolarRadiation, out double diffuseHorizontalRadiation)
{
directSolarRadiation = diffuseHorizontalRadiation = 0;
double io = GetExtraterrestrialRadiation(dTime.DayOfYear);
double sinH = Math.Sin(Sun.GetSunAltitude(latitude, xlongitude, sLongitude, dTime));
if (sinH <= 0.001) return;
//宇田川の手法
if (method == DiffuseAndDirectNormalRadiationEstimatingMethod.Udatgawa)
{
double ktc = 0.5163 + 0.333 * sinH + 0.00803 * sinH * sinH;
double ktt = Math.Min(1, globalHorizontalRadiation / (io * sinH));
if (ktc <= ktt) directSolarRadiation = (-0.43 + 1.43 * ktt) * io;
else directSolarRadiation = (2.277 - 1.258 * sinH + 0.2396 * sinH * sinH) * Math.Pow(ktt, 3) * io;
directSolarRadiation = Math.Min(directSolarRadiation, globalHorizontalRadiation / sinH);
diffuseHorizontalRadiation = globalHorizontalRadiation - directSolarRadiation * sinH;
}
//三木の手法
else if (method == DiffuseAndDirectNormalRadiationEstimatingMethod.Miki)
{
double lkt = Math.Min(1, globalHorizontalRadiation / (io * sinH));
double skt = (lkt - 0.15 - 0.2 * sinH) / 0.6;
double skd;
if (skt <= 0) skd = 0;
else skd = 3 * skt * skt - 2 * skt * skt * skt;
double lkd = Math.Min(skd * lkt, Math.Pow(0.8, (7 + sinH) / (1 + 7 * sinH)));
double lks = Math.Max(lkt - lkd, 0.005);
directSolarRadiation = lkd * io;
directSolarRadiation = Math.Min(directSolarRadiation, globalHorizontalRadiation / sinH);
diffuseHorizontalRadiation = globalHorizontalRadiation - directSolarRadiation * sinH;
}
//数値計算による方法
else
{
double atmTrans = estimateAtmosphericTransmissivity(sinH, io, globalHorizontalRadiation, method);
estimateRadiationFromAtmosphericTransmissivity(atmTrans, sinH, io, method, out directSolarRadiation, out diffuseHorizontalRadiation);
}
//0以上とする
directSolarRadiation = Math.Max(0, directSolarRadiation);
diffuseHorizontalRadiation = Math.Max(0, diffuseHorizontalRadiation);
}
/// <summary>日射に関する大気透過率[-]に基づいて法線面直達日射[W/m2]と水平面天空日射[W/m2]を推定する</summary>
/// <param name="atmosphericTransmissivity">日射に関する大気透過率[-]</param>
/// <param name="sinH">太陽高度の正弦</param>
/// <param name="extraterrestrialRadiation">大気圏外日射[W/m2]</param>
/// <param name="method">推定手法</param>
/// <param name="directNormalRadiation">法線面直達日射[W/m2]</param>
/// <param name="diffuseHorizontalRadiation">水平面天空日射[W/m2]</param>
private static void estimateRadiationFromAtmosphericTransmissivity(double atmosphericTransmissivity, double sinH,
double extraterrestrialRadiation, DiffuseAndDirectNormalRadiationEstimatingMethod method,
out double directNormalRadiation, out double diffuseHorizontalRadiation)
{
double pcosech = Math.Pow(atmosphericTransmissivity, 1 / sinH);
directNormalRadiation = extraterrestrialRadiation * Math.Pow(atmosphericTransmissivity, 1 / sinH);
diffuseHorizontalRadiation = 0;
switch (method)
{
case DiffuseAndDirectNormalRadiationEstimatingMethod.Akasaka:
//赤坂の手法
diffuseHorizontalRadiation = sinH * extraterrestrialRadiation * (1 - pcosech) * 0.95 *
Math.Pow(atmosphericTransmissivity, 1 / (0.5 + 2.5 * sinH)) * Math.Pow(1 - atmosphericTransmissivity, 2d / 3d);
break;
case DiffuseAndDirectNormalRadiationEstimatingMethod.Berlage:
//Berlageの手法
diffuseHorizontalRadiation = sinH * extraterrestrialRadiation * (1 - pcosech) *
0.5 / (1 - 1.4 * Math.Log(atmosphericTransmissivity));
break;
case DiffuseAndDirectNormalRadiationEstimatingMethod.LiuAndJordan:
//Liu&Jordanの方法
diffuseHorizontalRadiation = sinH * extraterrestrialRadiation * (0.271 - 0.2939 * pcosech);
break;
case DiffuseAndDirectNormalRadiationEstimatingMethod.Matsuo:
//松尾の手法
diffuseHorizontalRadiation = sinH * extraterrestrialRadiation * (1 - pcosech) * (1 - atmosphericTransmissivity) *
1.2 / (1 - 1.4 * Math.Log(atmosphericTransmissivity));
break;
case DiffuseAndDirectNormalRadiationEstimatingMethod.Nagata:
//永田の手法
diffuseHorizontalRadiation = sinH * extraterrestrialRadiation * (1 - pcosech) *
(0.66 - 0.32 * sinH) * (0.5 + (0.4 - 0.3 * atmosphericTransmissivity) * sinH);
break;
case DiffuseAndDirectNormalRadiationEstimatingMethod.Watanabe:
//渡辺の手法
double qq = (0.9013 + 1.123 * sinH) * Math.Pow(atmosphericTransmissivity, 0.489 / sinH) * Math.Pow(1 - pcosech, 2.525);
diffuseHorizontalRadiation = sinH * extraterrestrialRadiation * qq / (1 + qq);
break;
}
}
/// <summary>水平面天空日射[W/m2]に基づいて大気透過率[-]を推定する</summary>
/// <param name="sinH">太陽高度の正弦</param>
/// <param name="extraterrestrialRadiation">大気圏外日射[W/m2]</param>
/// <param name="globalHorizontalRadiation">水平面天空日射[W/m2]</param>
/// <param name="method">推定手法</param>
/// <returns>大気透過率[-]</returns>
private static double estimateAtmosphericTransmissivity(double sinH, double extraterrestrialRadiation,
double globalHorizontalRadiation, DiffuseAndDirectNormalRadiationEstimatingMethod method)
{
//入力異常判定
if (sinH <= 0) return 0;
if (extraterrestrialRadiation < globalHorizontalRadiation) return 0;
if (globalHorizontalRadiation <= 0) return 0;
//初期値
double atmTrans = 1;
//収束計算実行;
int iterNum = 0;
const int MAX_ITER = 20;
const double DELTA = 0.0001;
const double ERR_TOL = 0.001;
double dn, dff;
double err1, err2;
estimateRadiationFromAtmosphericTransmissivity(atmTrans, sinH, extraterrestrialRadiation, method, out dn, out dff);
err1 = globalHorizontalRadiation - (dn * sinH + dff);
while (true)
{
estimateRadiationFromAtmosphericTransmissivity(atmTrans - DELTA, sinH, extraterrestrialRadiation, method, out dn, out dff);
err2 = globalHorizontalRadiation - (dn * sinH + dff);
atmTrans -= err2 * DELTA / (err1 - err2);
estimateRadiationFromAtmosphericTransmissivity(atmTrans, sinH, extraterrestrialRadiation, method, out dn, out dff);
err1 = globalHorizontalRadiation - (dn * sinH + dff);
if (Math.Abs(err2) < ERR_TOL) break;
iterNum++;
if (MAX_ITER < iterNum) break;
}
return atmTrans;
}