Abstract: The high voltage short distance 35 kV feeding transmission system is one of the common short distance power systems . According to the physical equipment, the author takes to partitioning the system. The transmission module is used as a lumped parameter model, synchronous generator, transformer, composite load are separately operated as independent built-modules. Every module connection is substituted by a decoupled voltage source. So every module can take parallel integration.  A mathematics model of feed power system non-three phase running is developed on the basis of known model of synchronous machine and composite load .The digital integration method is also given .The results of a digital example simulation running on Pentium III show that the presented model and the given digital integration method are correct and can be realized in real-time.

Key words: digital real-time simulation, transmission line, mathematics model, non-three phase