The first category: Core processing equipment
The core is the magnetic circuit core of a transformer, and its processing quality directly affects the no-load loss and noise.
1.Silicon steel sheet slitting line: Cut large rolls of silicon steel sheets into the required strips according to the designed width.
2. Silicon steel sheet transverse shearing line: The longitudinally sheared strip material is punched and sheared into specific shapes such as "E" and "F" according to the designed dimensions. Modern cross-cutting lines are core equipment that is automated and highly precise.
3. Core stacking platform/tooling: It is used to stack the punched and cut silicon steel sheets one by one in an interlaced manner to form core columns and yokes. There are manual, semi-automatic and fully automatic stacking systems.
4. Core binding equipment: Use resin-impregnated fiberglass tape (non-woven tape) or steel tape to fasten the stacked cores.
Tensioner/tensioning tool: Manual or pneumatic, used for tensioning the binding strap.
Curing equipment (if required) : Heat and cure the unwoven tape.
The second category: Winding manufacturing equipment
The winding is the circuit part of a transformer and is of Paramount importance in production.
Winding machine: Core equipment, with various types:
Low-voltage foil winding machine: It is used for winding low-voltage side foil windings (with copper foil or aluminum foil). It can automatically complete the uncoiling of foil materials, the placement of interlayer insulation, and the welding of end ends, etc.
High-voltage winding machine: It is used for winding high-voltage side wire winding (with round wire or flat wire). It is available in vertical and horizontal types, and usually comes with a numerical control system, tension control, and automatic wire arrangement functions.
Spiral winding machine: Used for low-voltage spiral windings with high current.
Winding machine: It is used for winding the windings of winding (resin casting) transformers, wrapping glass fibers and pre-impregnating resin while winding the wires.
2. Coil press/shaping machine: It performs axial height compression and shaping on the wound coils to ensure that the dimensions meet the design requirements.
3. Coil pouring mold (for resin pouring dry-type transformers) : This is the core of the pouring transformer, with extremely high precision requirements for the mold to ensure the size and insulation thickness of the coil after pouring.
4. Vacuum casting equipment (for resin casting and drying) :
Vacuum pouring tank: In a highly vacuum environment, the epoxy resin mixture is injected into the mold to remove air bubbles.
Mixing tank/metering system: Precisely mix resin, curing agent and filler.
Preheating furnace: Preheat the coil and mold before pouring to reduce the viscosity of the resin.
5. Curing oven/oven: It is used to dry and cure the wound (non-cast) coils, or to heat and cure the cast coils.
The third category: Assembly and final assembly equipment
Assemble the core and windings into the transformer body.
1. Assembly platform/rack: A sturdy platform for core inserts, coil sets and overall assembly.
2. Lifting equipment: Overhead cranes/bridge cranes, which are essential for factories, are used for hoisting cores, coils and finished products.
3. Winding forming/support plate disassembly equipment: For non-cast transformers, the temporary support bars and partitions used during winding need to be disassembled.
4. Lead-making equipment
Busbar bending machine/cutting machine: Processing copper busbars or aluminum busbars.
Argon arc welding machine: It is used for the welding connection between the winding head and the external casing.
5. Vacuum pressure impregnation equipment (for VPI process dry transformers) : Place the assembled transformer as a whole into the impregnation tank, evacuate the air, inject insulating varnish, and then apply pressure to ensure the insulating varnish penetrates thoroughly.
Category Four: Detection and testing equipment
Ensure that every transformer leaving the factory complies with standards and specifications.
1. Routine test station
Ratio tester: Measures voltage ratio.
Dc resistance tester: Measures the DC resistance of windings and checks the quality of wire connections and welding.
Power frequency withstand voltage test bench: Conduct external construction frequency voltage tests to inspect the main insulation.
Induced voltage test bench: For conducting induced voltage and partial discharge quantity tests.
Partial discharge test system: A key device used to measure and locate the partial discharge quantity inside the transformer, it is a core indicator for evaluating the insulation quality of dry-type transformers.
No-load loss and no-load current testing system.
Load loss and short-circuit impedance testing system.
2. Type test equipment (partially shared with routine tests) :
Impulse voltage generator: Conduct lightning impulse voltage tests.
Temperature rise test system: It simulates the operating state through the short-circuit method and measures the temperature rise of each part of the transformer.
Category Five: Auxiliary and public facilities
1. Insulating parts processing center: CNC machining center/engraving machine, used for cutting and engraving insulating cardboard, insulating cylinders, struts, etc.
2. Workshop constant temperature and humidity system (especially for the pouring area) : Strictly control the temperature and humidity of the environment to prevent the coils from getting damp and ensure the quality of pouring and curing.
3. Compressed air system: Provides power for various pneumatic tools and equipment.
4. Complete set of toolboxes: including torque wrenches, special fixtures, etc.
In simple terms, a modern dry-type transformer production line is a complex integration of machinery (winding machines), electricity (testing equipment), liquid (pouring /VPI equipment), and gas (control and tools).
For the dry transformation of epoxy resin casting, the vacuum casting system and the partial discharge testing system are lifelines.
For VPI impregnation dry transformation, vacuum pressure impregnation equipment and curing furnaces are key.