Electromagnetic Transient Equivalent Modeling and Real-Time Simulation Method for Bidirectional DC/DC Converters

The bidirectional DC/DC converter (BDC) are widely used in modern power systems. However, the simulation scale of the network is limited by the nonlinearity of the BDC and the alteration of nodal admittance matrix due to frequent switching events. This paper proposes an efficient electromagnetic transient (EMT) equivalent modeling and real-time simulation method with constant admittance to overcome the above limitation. Firstly, a state-space equation is established based on the characteristics of the BDC ports and the switching states. Subsequently, a novel <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ϕ</i>-step predictive correction algorithm is proposed. Based on this, an adjoint companion circuit for decoupling the ac and dc sides is derived. Furthermore, the proposed model can eliminate the time-delay between the adjoint circuit and the global solution of the system, which can effectively improve the simulation accuracy compared with the classical time-delay method. Finally, the advantages of the proposed method in terms of accuracy, efficiency and practicality are validated through offline and hardware-in-the-loop (HIL) simulations.