As the factors of interruption

latency and bit-error-rate(BER)of the communication play a very important role in the security and stability control of power system for the smart grid and the Energy Internet. So it is important to study the interaction between the power system and the communication network

and the hardware-in-the-loop co-simulation is a very useful tool for this kind of study. Based on the analysis of dynamic features and the characteristics of synchronous digital hierarchy(SDH)network

a framework of a hardware-in-the-loop co-simulation system for power system and communication network using the real time digital system(RTDS)and QualNet are introduced. Then

a hardware-in-the-loop co-simulation system for the power system and communication network with power system secondary control equipment and SDH equipment is developed to study the impact of communication failure on the power stability control system. Tests are done to measure the inherent latency of the developed co-simulation system to verify the reliability. Finally

the frequency coordinated control system in East China grid territory is used as an example

and a close-loop simulation is performed in the co-simulation system to validate the impact of the communication BER on the functions of the stability control system and the control effect.