We study the problem of balancing of renewable generation of solar power park in Kazakh high-voltage electric power system, which characterized with lack of balancing capacity, large spatial diversity of energy production and consumption facilities, the extension of high-voltage transmission lines and lack of modern compensators of reactive power. We develop a simulating power flow model of Kazakhstan grid as add-on structure on the known equivalent power flow model for the existing power system. This approach allows to analyze the properties of the real system in time and its parameters as voltage, active and reactive power by means of simulation techniques. We apply dynamic programming method and obtain estimation of the maximum power of renewables, which can be integrated in the power system.