Computer simulations of pumps drive system during additional induction motor connecting

The problem of suitable water pump drive system selection step forward in many water pump stations. It should be a compromise among the price of drive and the best technical parameters. The most imortant technical parameter for water receiver is pressure. It should be constant. The paper presents results of computer simulations of pump drive system during adding the second induction motor supply from power network. There is shown the matemathical model of PWM inverter, induction motor and the characteristic of pump. The pump drive system consists of two induction motors - one supply from PWM inverter, the second from power network. The second induction motor is connected when demand for water is higher than delivery of a pump fed by the controled motor