## 1 Introduction  
Power converters are one of the standard components of power electronic systems, since they allow for the integration and control of the different blocks that determine their architecture [1, 2]. The field of application of power converters and, in particular, DC/DC converters, is huge [3, 4]. Thus, for example, in power grids, especially in renewables ones, DC/DC power converters connect the generators to the buses, so they are the elements that allow for the coupling of both impedances to deliver regulated power to the buses [5, 6]. Currently, there are multiple power converter topologies, and among them, the push-pull topology stands out as one of the most widely used in the design of switched-mode power supplies, and DC/DC converters and power inverters, forming fundamental pillars for the definition of the architecture and control of power systems [7, 8]. In particular, the push-pull topology is becoming of great interest for the design and control of power systems in applications as diverse as electric vehicles [9], energy conversion in renewable microgrids [7], high-voltage direct-current (HVDC) transmission lines [10] and the integration and control of energy storage systems based on batteries or hydrogen technologies [11]. This is due to several factors, including the following: its simplicity, due to the reduced number of switching devices [12]; its versatility, as the use of a high-frequency (HF) transformer allows for the design of buck or boost topologies without restrictions in the conversion ratio or modifications in the topology [13]; its scalability, as its operating power can vary from a few watts to hundreds of kW [14]; and its excellent performance compared to other isolated topologies [14]. Among other reasons, these contribute to the interest in the study of this topology. For the correct design, simulation, implementation and control of push-pull converters in real applications, it is very useful to have analytical models whose behavior is as close as possible to that of the real converter [15; 16]. This, among other things, allows for studies to improve the converter's performance, as well as the prediction and analysis of its dynamic and stationary responses depending on the application. A good converter model, regardless of its formulation, must combine accuracy and modularity and, at the same time, guarantee the practical computability required for the design of real-time controllers. Therefore, according to these requirements, it is fundamental that a push-pull converter model that is considered general and complete considers all its practical non-idealities. In addition, its formulation must, on the one hand, facilitate its fast computation, and, on the other hand, be able to adapt to the variations in the non-idealities depending on the operating conditions of the converter. These premises comprise the starting point for this research. Depending on the non-idealities that are considered and the adopted simplifications, the modeling solutions found in the literature are diverse in terms of complexity and purpose. To facilitate their study and highlight the contributions of this research, the models studied in the scientific literature have been grouped according to the considered parameters, using the following classification. First, the simplest and most widespread solutions, called type 1 models (T1M), are based on the ideal model of the HF transformer and all switching devices (transistors and diodes). Depending on the model, losses associated with the inductance and the filter capacitor (Figure 1) can be considered. This allows, by applying the converter transformation ratio, for the proposal of a simplified circuit with respect to the transformer secondary, with behavior, architecture, and model resembling that of an equivalent buck converter. These models have been successfully used in multiple applications with different formulations.