На примере сети электроснабжения со случайной электрической нагрузкой рассмотрена задача выбора объектов электроустановок по нагреву. Средняя температура перегрева вычислена путём умножения коэффициента теплоотдачи проводника на квадрат эффективного тока. Для уменьшения объёма вычислений по ней определен диапазон двух соседних постоянных времени нагрева (ПВН), в котором априори находится расчётная ПВН. Разработан метод выбора сечения проводников по нагреву при случайной электрической нагрузке без противоречащей физике задачи допущений. Задача нагрева решена путём имитации двух ансамблей случайных реализаций температуры. Статистические функции распределения определены по сечениям ансамблей в установившемся режиме. По ним вычислены инерционные максимумы температуры (ИМТ) с заданной интегральной вероятностью. Для нахождения расчётной ПВН по координатам границ диапазона осуществлена аппроксимация зависимости от ПВН инерционных максимумов температуры. Чтобы избежать итераций, предложено искомую ПВН однозначно определить как абсциссу точки пересечения ИТМ-характеристики с горизонталью допустимой температуры. Расчётная токовая нагрузка вычислена по расчётной температуре. Найдены коэффициенты запаса выбранного проводника по температуре, току и тепловому износу изоляции. Полученные результаты могут быть использованы для тестирования существующих, а также разработки физически обоснованных методов расчёта электрических нагрузок.

The problem of selecting electrical installation objects for heating is considered using the example of a power supply network with a stochastic electrical load. The average superheat temperature is calculated by multiplying the heat transfer coefficient of the conductor by the square of the effective current. To reduce the amount of calculations on it, the range of two adjacent heating time constants (HTC) is determined, in which the calculated HTC is located a priori. A method for selecting the cross-section of conductors for heating under stochastic electrical load without assumptions that contradict the physics of the problem has been developed. The heating problem was solved by simulating two ensembles of stochastic temperature realizations. Statistical distribution functions are determined from cross sections of ensembles in a steady state. Based on them, inertial temperature maxima (IMT) with a given integral probability were calculated...

The problem of selecting electrical installation objects for heating is considered using the example of a power supply network with a stochastic electrical load. The average superheat temperature is calculated by multiplying the heat transfer coefficient of the conductor by the square of the effective current. To reduce the amount of calculations on it, the range of two adjacent heating time constants (HTC) is determined, in which the calculated HTC is located a priori. A method for selecting the cross-section of conductors for heating under stochastic electrical load without assumptions that contradict the physics of the problem has been developed. The heating problem was solved by simulating two ensembles of stochastic temperature realizations. Statistical distribution functions are determined from cross sections of ensembles in a steady state. Based on them, inertial temperature maxima (IMT) with a given integral probability were calculated. To find the calculated HTC from the coordinates of the range boundaries, the dependence of the inertial temperature maxima on the PVN was approximated. To avoid iterations, it is proposed to unambiguously define the required HTC as the abscissa of the point of intersection of the ITM characteristic with the horizontal of the permissible temperature. The rated current load is calculated based on the rated temperature. The safety factors of the selected conductor for temperature, current and thermal wear of the insulation are found. The results obtained can be used to test existing methods, as well as to develop physically based methods for calculating electrical loads.