mode while in events to avoid corresponding impacts on the distribution system and supply the local loads [9]. Furthermore, the deployment of MGs and SGs including electric vehicles can enhance system reliability and resiliency of the power distribution system in responding to extreme operating conditions [10; 11]. As noted, it has been seen that the integration of RESs has increased during the past few decades, which plays a crucial role in the distribution systems for grid modernization [12]. However, due to the intermittency of the RESs, it has certain challenges, which make the system complex and unstable. The most noticeable challenge is uncertainty, which means it depends on environmental factors such as solar insolation and wind speed for solar and wind systems, respectively [13]. To deal with these challenges, the advanced power electronics in distribution systems play a crucial role in regard to the control of power (both active and reactive power) flow to enable DC-operated technology [14], protection [15], mitigating the power quality issues, and reducing harmonics. To address these benefits, power electronics are reconfigured in a different way to make it possible for the determination of power quality problems [16]. It is critical for the distribution networks that the reliability factor is always a prime concern. With this objective, using a modern power electronics device, a solid-state device is pronounced, named the SST. SST is treated as an evolving technology for providing power supply to the consumer through MGs or SGs [17]. Besides, the SST is a high-frequency transformer with a power electronic converter and is an alternative to the traditional bulky and non-smart transformer. In the past decades, researchers have shown interest in modeling and the development of SST for MG and SG applications. In [18; 19], the design and response of SSTs are addressed through their converter stages and controllers. In [20], average models and their controllers are proposed and explored through descriptive simulation studies. Further, in [21], the stability aspect of SST and validation, which has been done through the distribution system, is presented. In this regard, many motivating test models of transient instabilities have been developed, and their importance to the link topologies of SSTs in various operating regions is demonstrated [22]. The most prominent manufacturers of SST, namely, ABB, ETH Zurich, EPRI, Siemens, and FREEDM Systems Center, have conducted cutting-edge research to upgrade the conventional transformer to an intelligent one. They have designed and tested various topologies to improve the performance and facilities of SST to the connected devices [23; 24; 25]. In [26], the FREEDM Systems Center is presented with a start-up SST structure named Generation-1-SST, which can be used in medium-voltage-based MG. Further development has been done with a multi-cell-based DC-DC converter for SST, which is proposed in [27]. In [28], the stability of the SST has been studied with different control methods by incorporating renewable energy resources. [PERSON]'s criterion is used to check the stability. In [29], small-signal stability of SST is studied using a dynamic phasor-based model. [PERSON] et al. [21] analyzed the SST stability on account of harmonic resonance in the distribution system. Extending to the study on [21], the modified source impedance-based stability criterion has been proposed [30]. The stability analysis considers a Z+Z type cascade system, an impedance analysis in SST explained in [31]. However, the research on SST stability is lacking in the literature and must be considered a vital factor. Thus, the stability aspect of each stage (input, isolation, and output) of the SST needs to be emphasized, which this paper addresses. This study develops a state-space and a transfer-function-based model with a proper SST controller to reduce system complexity and cost. The state-space parameters (A, B, C, and D) of the converter's input, isolation, and output stages are estimated.