◎ Performance Features

The ZQSCB series products (traction rectifier transformers) use 30QG120 high-permeability grain-oriented silicon steel sheets as the core material, with 45° fully mitered joints and five-step lamination (allowing magnetic lines to smoothly avoid air gaps between laminations and enter adjacent laminations vertically). The coils are wound with high-quality cold-drawn copper conductors and adopt nano-coating materials developed for marine environments to prevent mold, moisture, and smoke, solving the humidity issues in subway rectifier transformer operating environments. Additionally, the design process references marine transformer design specifications, increasing insulation margins to further improve transformer operational reliability. To meet Class VI load requirements, magnetic density and current density are reasonably selected during design, axial air ducts are provided between each layer of winding conductors, and a thin insulation structure is adopted to ensure good heat dissipation performance.

◎ Technical Features

■ When two units are operating, it achieves 24-pulse operation; a single unit can also operate in 12-pulse mode, greatly improving system reliability. The total harmonic current to the grid in a 24-pulse rectifier system is reduced by more than 60 compared to 12-pulse. Each tap phase shift angle is 7.5°, with equally low harmonic content during each tap operation.

■ Low temperature rise, strong overload capacity, reliable operation under Class VI load conditions.

■ By simply changing the external high-voltage connection sequence of the transformer, mutual exchange of ±7.5° phase shift between two products can be achieved, convenient for users.

■ Good balance of key technical parameters, uniform load distribution, effectively reducing non-characteristic harmonics.

■ Coils adopt axial double-split structure, smooth output DC waveform, eliminating the need for smoothing reactors. This simplifies the grid structure and saves investment.

◎ Technical Specifications

■ Voltage level: Grid side: 10kV, 20kV, 35kV or as specified by user; Valve side: 1.18kV~1.22kV or as specified by user

■ Capacity: 1000~5000kVA

■ Voltage regulation range: ±5%, ±2x2.5% or as required by user

■ Voltage regulation method: No-load tap changing

■ Frequency: 50Hz

■ Connection group: Dd0,y5 and Dd2,y7 or as required by user

■ Cooling method: AN

■ Load class: VI or as required by user

Insulation heat resistance class: H

■ Partial discharge: 10kV~35kV ≤ 5pC

■ Insulation level:

3kV and below power frequency withstand 10kV; impulse voltage 20kV

10kV power frequency withstand 28(35)kV; impulse voltage 75kV

35kV power frequency withstand 70kV; impulse voltage 170kV