1. Technical characteristics of urban rail feedback transformer
·The bidirectional power operation design can take power from the grid in the forward direction and feedback braking energy to the grid in the reverse direction. The winding structure takes into account bidirectional current flow and can withstand the alternating impact load caused by frequent power commutation.
The strong harmonic suppression and low additional loss feedback converter generates a large amount of high-frequency harmonics. The product adopts a transposed wire, low hysteresis iron core, and shielded winding structure to significantly reduce harmonic additional losses and avoid long-term harmonic heating and aging.
The train is resistant to frequent impact overload, with frequent start stop and braking alternation. The short-term feedback impact current is large, and the dynamic and thermal stability margin of the winding is greatly improved, which can withstand periodic short-term overload conditions.
High insulation, low partial discharge dry-type structure vacuum epoxy integral casting, extremely low partial discharge, oil-free, non flammable and explosion-proof, suitable for damp and enclosed spaces in underground stations, eliminating fire and leakage hazards.
Electrical isolation is safe, reliable, and has high insulation strength for high and low voltage windings. It blocks high-frequency interference from the feedback side from entering the main power grid and protects medium voltage distribution equipment and other precision control devices in the station.
The low-noise shock-absorbing structure is equipped with elastic shock-absorbing supports, optimized iron core magnetostriction, strictly controls operating noise, and meets the noise reduction standards for underground computer rooms.
Complete temperature monitoring and protection winding pre embedded PT100 temperature measuring element, which can be connected to the comprehensive monitoring system of the substation, real-time monitoring of temperature rise, automatic alarm for over temperature, and interlocking shutdown.
Energy saving and low-carbon combined with energy feedback devices to recover train braking energy, reduce the traction power consumption of the entire subway line, reduce the peak electricity load of the power grid, and adapt to the construction of green rail transit
2. Product features
2.1 Design standards: GB, IEC
2.2 Capacity (MVA): 0.5 to 3.2
2.3 Voltage (KV): 10-35
2.4 Cooling method: AN/AF
2.5 Installation location: Underground traction substation of subway, distribution substation of ground light rail, underground substation of urban rapid transit, regenerative energy room of vehicle depot, limited to indoor ventilated enclosed room.
2.6 Application scenarios: Urban subway lines, light rail transit, trams, urban rapid transit, and regenerative braking energy recovery systems for subway vehicle depots and parking lots.
2.7 Insulation level: F/H
2.8 Operating environment
·Environmental temperature: ambient air temperature -35 ℃~+40 ℃;
Altitude: ≤ 1000m. High altitude mountain rail transit can be customized to strengthen insulation and increase heat dissipation specifications;
Atmospheric conditions: The relative humidity of the underground computer room is ≤ 95% (no condensation), and there are no highly corrosive, flammable, or explosive gases or dust. The computer room is equipped with a forced ventilation and dehumidification system;
Installation conditions: Good indoor ventilation, shock-absorbing rubber pad installed on the base, optional IP21 protective shell to prevent debris and moisture from contacting the winding.
2.9 Types
According to the DC system of the rail network: DC750V with feedback transformer, DC1500V with feedback transformer;
By cooling method: AN natural cooling type, AF forced air cooling type;
According to the insulation structure: epoxy resin casting dry feedback transformer, large capacity VPI vacuum impregnation non encapsulated feedback transformer;
According to protection level: IP00 open type, IP21 computer room closed type;
According to the harmonic control plan: standard single winding feedback transformer, multi winding low harmonic feedback transformer.
