# 计算直线塔不平衡张力 # 新版输电线路大手册 P328 import math # h_i 悬点高差 # l_i 悬点档距 # _alpha 导线膨胀系数 1/°C # _elastic 弹性系数 N/mm2 # _t_e 架线时考虑初伸长的降温,取正值。单位°C # lambda_i 计算不平衡张力时导线比载 N/(m.mm) # sigma_i 计算不平衡张力时最低点水平应力 单位N/mm2 # t_i 计算不平衡张力时导线温度 单位°C # _lambda_m 导线架线时时导线比载 N/(m.mm) # _sigma_m 导线架线时时最低点水平应力 单位N/mm2 # _t_m 导线架线时时导线温度 单位°C def delta_li( h_i: float, l_i: float, lambda_i: float, _alpha: float, _elastic: float, _t_e: float, t_i: float, sigma_i: float, _lambda_m: float, _t_m: float, _sigma_m: float, ) -> float: beta_i = math.atan(h_i / l_i) # 高差角 _delta_li = ( l_i / ((math.cos(beta_i) ** 2) * (1 + (lambda_i * l_i / sigma_i) ** 2 / 8)) * ( (l_i * math.cos(beta_i)) ** 2 / 24 * ((_lambda_m / _sigma_m) ** 2 - (lambda_i / sigma_i) ** 2) + ((sigma_i - _sigma_m) / _elastic / math.cos(beta_i)) + _alpha * (t_i + _t_e - _t_m) ) ) return _delta_li # area 导线截面 单位mm2 # sigma_i 第i档内水平应力 单位N/mm2 # b_i 悬垂串沿线路方向水平偏移距离,沿大号方向为正,反之为负。 单位m # length_i 第i基直线塔串长 单位m # g_i 第i基直线塔串重 单位N # h_i 悬垂串处千中垂位置时,,第 i 基对第 i-1 杆塔上导线悬挂点间的高差大号比小号杆塔悬挂点高者h本身为正值,反之为负值。 # lambda_i 第i档导线比载 N/(m.mm) # h_i1 悬垂串处千中垂位置时,第 i+1 基对第 i 杆塔上导线悬挂点间的高差大号比小号杆塔悬挂点高者h本身为正值,反之为负值。 # lambda_i1 def fun_sigma_i1( area: float, sigma_i: float, b_i: float, length_i: float, g_i: float, h_i: float, l_i: float, lambda_i: float, h_i1: float, l_i1: float, lambda_i1: float, ): beta_i = math.atan(h_i / l_i) beta_i1 = math.atan(h_i1 / l_i1) _sigma_i1 = ( ( g_i / 2 / area + lambda_i * l_i / 2 / math.cos(beta_i) + lambda_i1 * l_i1 / 2 / math.cos(beta_i1) + sigma_i * h_i / l_i ) + sigma_i / b_i * math.sqrt(length_i ** 2 - b_i ** 2) ) / (math.sqrt(length_i ** 2 - b_i ** 2) / b_i + h_i1 / l_i1) return _sigma_i1 # 求解循环。 def cal_loop(): loop_end = 100000 # 最大循环次数 # 架线时的状态 # 取外过无风 string_length = 9.2 # 串长 单位m string_g = 60 * 9.8 # 串重 单位N t_m = 15 # 导线架设时的气温。单位°C t_e = 20 # 架线时考虑初伸长的降温,取正值。单位°C alpha = 0.0000155 # 导线膨胀系数 1/°C elastic = 95900 # 弹性系数 N/mm2 area = 154.48 # 导线面积 mm2 lambda_m = 14.8129 / area # 导线比载 N/(m.mm) # 取400m代表档距下 sigma_m = 28517 / area # 架线时,初伸长未释放前的最低点水平应力。单位N/mm2 span_count = 3 # 几个档距 # n个档距,n-1个直线塔 h_array = [0, 0, 0] l_array = [400, 400, 400] t_array = [15, 15, 15] lambda_array = [lambda_m, lambda_m, lambda_m] loop_count = 1 sigma_0 = sigma_m * 0.8 while True: sigma_0 = sigma_0 + 0.001 sigma_array = [sigma_0, 0, 0] b_i = 0 delta_l_i_array = [] for i in range(span_count - 1): h_i = h_array[i] l_i = l_array[i] lambda_i = lambda_array[i] t_i = t_array[i] sigma_i = sigma_array[i] _delta_l_i = delta_li( h_i, l_i, lambda_i, alpha, elastic, t_e, t_i, sigma_i, lambda_m, t_m, sigma_m, ) delta_l_i_array.append(_delta_l_i) b_i += _delta_l_i length_i = string_length g_i = string_g h_i1 = h_array[i + 1] l_i1 = l_array[i + 1] lambda_i1 = lambda_array[i + 1] sigma_i1 = fun_sigma_i1( area, sigma_i, b_i, length_i, g_i, h_i, l_i, lambda_i, h_i1, l_i1, lambda_i1, ) sigma_array[i + 1] = sigma_i1 # print("第{loop_count}轮求解。".format(loop_count=loop_count)) # print(b_i) loop_count += 1 if math.fabs(b_i) < 1e-5: print("迭代{loop_count}次找到解。".format(loop_count=loop_count)) print("悬垂串偏移累加bi为{b_i}".format(b_i=b_i)) for i in range(span_count): print("第{i}档导线应力为{tension}".format(i=i, tension=sigma_array[i])) for i in range(span_count - 1): print("第{i}串偏移值为{bias}".format(i=i, bias=delta_l_i_array[i])) verify( area, h_array, l_array, string_length, string_g, sigma_array, delta_l_i_array, lambda_array, ) break if loop_count >= loop_end: print("!!!未找到解。") print(sigma_array) print(b_i) break # 检验等式。 def verify( area: float, h_array: [float], l_array: [float], string_length: [float], string_g: [float], sigma_array: [float], delta_l_i_array: [float], lambda_array: [float], ): # 用新版大手册p329页(5-61)最第一个公式校验 for i in range(len(delta_l_i_array)): sigma_i = sigma_array[i] sigma_i1 = sigma_array[i + 1] left_equ = sigma_array[i + 1] _delta_l_i = delta_l_i_array[i] lambda_i = lambda_array[i] lambda_i1 = lambda_array[i + 1] h_i = h_array[i] h_i1 = h_array[i + 1] l_i = l_array[i] l_i1 = l_array[i + 1] beta_i = math.atan(h_i / l_i) beta_i1 = math.atan(h_i1 / l_i1) w_i = ( lambda_i * l_i / 2 / math.cos(beta_i) + sigma_i * h_i / l_i + (lambda_i1 * l_i1 / 2 / math.cos(beta_i1) - sigma_i1 * h_i1 / l_i1) ) right_equ = sigma_i + delta_l_i_array[i] / math.sqrt( string_length ** 2 - delta_l_i_array[i] ** 2 ) * (string_g / 2 / area + w_i) if math.fabs(right_equ - left_equ) > 1e-4: print("!!!等式不满足") return print("等式满足。") cal_loop() print("Finished.")