The paper presents the theoretical background and implementation details of a multi-domain symbolic analysis program developed with the emphasis on linearized hybrid systems combining classical electrical circuits, controllers, electro-mechanical converters and mechanical parts of electric drives. The systems analyzed can be composed of both basic elements and more complex behavioral blocks (regulators, converters, drives, etc.). All models are defined in an easily extensible library. Implemented algorithms for equation/matrix-based symbolic simplification allow obtaining symbolic expressions of acceptable complexity even for larger systems.