Mai suna Solid-State Transformer? 2025Tech, Bayanin Kaya da Muhimman Abubuwa

1. Me kana Solid-State Transformer (SST)?

1.1 Kudanci da Maimaita cikin Turbin Daɗi

Akwai wanda ake nuna tarihi (misali, patentin Stanley na 1886) da kuma kudanci masu yadda ake gina turbin daɗi. Turbin daɗi suna hana tsarin electromagnetic induction, suka shafi cores mai silikon steel, windings na copper ko aluminum, da kuma systems na insulation/cooling (mineral oil ko dry-type). Su yi aiki a wasu frequencies da ke fixe (50/60 Hz ko 16⅔ Hz), tare da voltage transformation ratios, power transfer capabilities, da kuma frequency characteristics da ke fixe.

Abubuwan da suka fiye cikin turbin daɗi:

• Yawan adadin raka

• Yakin amfani (efficiency >99%)

• Koyar da current daga short-circuit

Abubuwan da ba su fiye ba:

• Karin girman da kuma karfin yara

• Yanayi a kan harmonics da DC bias

• Ba da protection daga overload ba

• Risks na hoton kasa da environment

1.2 Taifi da Asalin Solid-State Transformers

Solid-State Transformer (SST) shine alternative zuwa turbin daɗi wadanda ake gina ta hanyar technology na power electronics, tare da asalin ya zama ne a shekarar 1968 a kan conceptin McMurray na "electronic transformer". SSTs sun samun voltage transformation da kuma galvanic isolation tare da Medium-Frequency (MF) isolation stage, da kuma ana bayarwa da multiple intelligent control functions.

Tsarin basic cikin SST shine:

• Medium-Voltage (MV) interface

• Medium-Frequency (MF) isolation stage

• Communication and control links

2. Abubuwan da suke Dukkake a Kan Design cikin SSTs

2.1 Abubuwa: Handling Medium Voltage (MV)

Levels na medium-voltage (misali, 10 kV) sun fiye da ratings na voltage cikin semiconductor devices da aka yi (Si IGBTs up to 6.5 kV, SiC MOSFETs ~10–15 kV). Saboda haka, ya kamata ake yi multi-cell (modular) ko single-cell (high-voltage device) approach.

Abubuwan da suka fiye cikin solutions na multi-cell:

• Design modular da redundant

• Multi-level output waveforms, take reduce filter requirements

• Support for hot-swapping and fault tolerance

Abubuwan da suka fiye cikin solutions na single-cell:

• Tsarin simpler

• Suitable for three-phase systems

2.2 Abubuwa: Topology Selection

Topologies na SST za su iya haɗa da:

• Isolated Front-End (IFE): Isolation before rectification

• Isolated Back-End (IBE): Rectification before isolation

• Matrix converter type: Direct AC-AC conversion

• Modular Multilevel Converter (M2LC)

2.3 Abubuwa: Reliability

Turbin daɗi suna da yakin amfani sosai, amma SSTs suna da semiconductors da yawa, control circuits, da kuma cooling systems, wanda ya zama abubuwa mai muhimmanci. A wannan paper an nuna Reliability Block Diagrams (RBD) da failure rate (λ in FIT) models, wadannan sun nuna cewa redundancy zai iya sa system reliability sosai.

2.4 Abubuwa: Medium-Frequency Isolated Power Converters

Common topologies include:

• Dual Active Bridge (DAB): Power flow controlled via phase shift, enabling soft switching

• Half-Cycle Discontinuous Mode Series Resonant Converter (HC-DCM SRC): Achieves ZCS/ZVS, exhibiting "DC transformer" characteristics

2.5 Abubuwa: Medium-Frequency Transformer Design

Transformers na medium-frequency sun yi aiki a frequencies na kHz-level, wadanda suna da abubuwan da suke dukkake kamar:

• Magnetic core volume na biyu

• Conflict between insulation and thermal management

• Uneven current distribution in Litz wire

2.6 Abubuwa: Isolation Coordination

Units na medium-voltage suna buƙaci yakin insulation da ground, wadanda ya kamata a duba:

• Combined 50 Hz power frequency and medium-frequency electric field stress

• Dielectric losses and risk of localized overheating

2.7 Abubuwa: Electromagnetic Interference (EMI)

Common-mode currents generated during MV switching can flow to ground through parasitic capacitance and must be suppressed using common-mode chokes.

2.8 Abubuwa: Protection

SSTs must handle overvoltage, overcurrent, lightning strikes, and short circuits. Traditional fuses and surge arresters remain applicable but should be combined with electronic current limiting and energy absorption strategies.

2.9 Abubuwa: Control

Control systems na SST suna da yawan hankali da suka buƙace hierarchical structure:

• External control: Grid interaction, power dispatch

• Internal control: Voltage/current regulation, redundancy management

• Unit-level control: Modulation and protection

2.10 Abubuwa: Construction of Modular Converters

Building practical MV modular systems involves:

• Insulation design

• Cooling systems

• Communication and auxiliary power

• Mechanical structure and hot-swappable support

2.11 Abubuwa: Testing of MV Converters

MV testing facilities are complex and require:

• High-voltage, high-power sources/loads

• High-precision measurement equipment (e.g., high-voltage differential probes)

• Backup test strategies (e.g., back-to-back testing)

3. Applicability and Use Cases of SSTs

3.1 Grid Applications

SSTs can be used in power grids for:

• Voltage regulation and reactive power compensation

• Harmonic filtering and power quality improvement

• DC interface integration (e.g., energy storage, photovoltaics)

However, compared to conventional Line Frequency Transformers (LFTs), SSTs face an "efficiency challenge":

• LFT efficiency can reach 98.7%

• SSTs typically achieve only ~96.3% due to multi-stage conversion

• Limited reduction in size and weight (~2.6 m³ vs. 3.4 m³)

• Significantly higher cost (>52.7k USD vs. 11.3k USD)

3.2 Traction Applications

Traction systems (e.g., electric locomotives) have stringent requirements for size, weight, and efficiency, where SSTs offer clear advantages:

• Significantly reduced transformer size through higher operating frequencies (e.g., 20 kHz)

• Dual optimization of efficiency and volume reduction

3.3 DC-DC Applications

In DC systems (e.g., offshore wind power collection, data centers), SSTs are the only viable isolation solution, as their operating frequency can be freely chosen without being constrained by grid frequency.

4. Future Concepts and Conclusion

4.1 Future Application Scenarios

• Subsea oil & gas processing systems

• Airborne wind turbines

• All-electric aircraft

• Naval medium-voltage DC (MVDC) systems