With the application of electronic transformers or merging units in digital substations， many new design and application problems may crop up. Some of the problems raised can be solved separately by manufacturers， while others can only be solved through consultations among the manufacturers involved. IEC 61850 standard does not mean just unified protocols and models， but also a change of the way product developers think and the adoption of a new function implementing mode to achieve the desired goals of IEC 61850 standard. Some new characteristics and new problems to be solved in the development of IEC 61850 systems are discussed. Corresponding workable ideas are put forward.