The advances of digital control systems require a new approach for design and development of power electronics devices. Modern simulation methods allow creating control systems of power converters based on their real microprocessor implementation. Thus, a digital control algorithm of device can be completely recreated, debugged and verified in the model. This paper proposes the control algorithm for parallel operation of AC/DC and DC/DC converters for microprocessor implementation. The simulation model has been developed in PSIM program considering features of construction real digital control systems.