Glance into solid-state transformer technology: a mirror for possible research areas

Abstract

Solid-State Transformer (SST), a power electronics based transformer is an emerging technology in electric power system. The transformer is being investigated to completely replace existing Line/Low Frequency Transformer (LFT). SST is composed of either of the two topologies: AC-DC-AC, two steps approach; or AC-AC, single-step approach. The two steps approach consists of three stages: AC-DC; DC-DC; and DC-AC stages. The DC-DC stage is made up of a boost DC-DC converter, a DC-AC inverter and a High Frequency Transformer, HFT. Therefore, SST performs the tasks of LFT by means of power electronic converters and HFT. The main essence of SST is to provide solution to the problem of bulkiness and heaviness of the LFT in the power distribution network. This is with the view to providing reduction in construction cost, cost of maintenance and transportation. The power electronics transformer provides numerous advantages which are grouped into: The transformer has high power density; it functions in blackouts and brownouts; and it provides easy means of distributed renewable energy integration into associated grid. Therefore, this paper provides a glance into the technology of the SST for its better understating and promotion of research activities in the area.

Assessment of the state-of-the-art of solid-state transformer technology: design, control and application

“…This type of SST uses a modular multilevel converter (MMC) fo the power conversion. The MMC is composed of multiple submodules, each containing a set of capacitors and power electronic switches, which are connected in series to produce a multilevel voltage output (Bignucolo, et al, 2015;Elrajoubi et al, 2019;Umar et al, 2020). The MMC-SST is well suited for high-power, high-voltage applications and offers improved voltage utilization, reduced harmonic distortion, and increased system efficiency compared to CHB-SSTs.…”

“…In other words, when an alternating voltage is applied to the coil's primary winding, an output voltage is induced in the secondary winding, allowing energy to be transmitted, a voltage or signal to be transformed, and electrical isolation to be provided. The primary difference is that, unlike the standard transformers, they operate at a much higher frequency (Bignucolo, et al, 2015;Elrajoubi et al, 2019;Umar et al, 2020). While must line voltage transformers operate at 50Hz or 60Hz, high frequency transformers operate at frequencies from 20KHz to over 1MHz.…”

“…(Battal et al, 2022;Bignucolo et al, 2021;Baizan et al, 2014;Al-Turki et al, 2024;Bignucolo, et al, 2015;Giesecke, et al, 2020;Elrajoubi et al, 2019). (Bignucolo, et al, 2015;Elrajoubi et al, 2019;Umar et al, 2020). BJT 1.…”

“…2. static charge problem. (Mishraa, et al, 2021;Sanchez & Molinas, 2024;Battal et al, 2022;Elrajoubi et al, 2019;Umar et al, 2020;Jia et al, 2021;Hadi & Mohammad, 2019)…”