High-Speed Motor Winding Wire Solutions

High-speed motors are widely used in new energy vehicles, air compressors, high-speed fans, industrial high-speed spindles, and aviation on-board power equipment, with rated speeds ranging from 15,000rpm to 30,000rpm, and some ultra-high-speed models can reach over 60,000rpm. Compared with conventional industrial frequency motors, high-speed motors have high operating frequency, strong alternating electric field, fast winding temperature rise, large mechanical centrifugal load, PWM high-frequency pulse shock, winding AC loss surge and other extreme conditions, the special winding wire (winding enameled wire) put forward far more than the ordinary motor wire stringent requirements.

This article is based on product development, matching conditions, mass production selection, pain point solution of four product perspectives, analysis of high-speed motor operating conditions and winding wire core pain points, a clear high-speed motor winding wire insulation system, conductor structure, mechanical properties, high-frequency loss of the four major product design logic.

Winding wire adapted to the high-speed motor extreme working conditions

High-speed motor exclusive compound working conditions

High-speed motors are different from ordinary low-speed motors in that the windings are subjected to four coupled stresses of electrical, thermal, mechanical, and environmental stresses at the same time, which is also the core basis for the differentiated design of special winding wire products. Electrical level: the motor operating frequency is greatly increased, superimposed on the SiC/IGBT inverter high-frequency carrier, the winding turns to withstand the steep edge of the PWM pulse voltage, the risk of partial discharge is greatly increased, the skin effect, the neighborhood effect induced by the high-frequency surges in the additional loss; Mechanical level: the rotor windings are subjected to ultra-high centrifugal pulling force, stator windings are subjected to high-frequency electromagnetic vibration, the paint is very prone to friction breakage and cracking off; Thermal conditions Level: high-frequency copper loss, iron loss superposition of heat concentration, closed cavity heat dissipation is poor, the winding hot spot temperature exceeds 180 ℃ ~ 220 ℃; process level: high-speed motor slot compact, dense winding arrangement, wire bending, embedded wire processing difficulty has increased dramatically.

High-speed motor winding wire requirements

Combined with automotive and industrial high-speed motor standards, dedicated high-speed winding wire must meet five major product thresholds: first, high PDIV corona-resistant insulation to resist high-frequency impulse partial discharge; second, 200℃~220℃ ultra-high heat-resistant insulation system to match the sustained high temperature buildup; third, low-loss conductor structure to weaken the high-frequency skin effect and reduce AC copper loss; Fourth, high adhesion dense paint film, high-frequency vibration resistance, resistance to centrifugal stretching, bending without cracking; Fifth, oil resistance, hydrolysis resistance, low dielectric properties, suitable for oil-cooled high-speed motors closed cooling conditions.

Typical failure problems of ordinary winding wire in high-speed motors

Conventional ordinary enameled wire, ordinary polyester imide enameled copper wire directly applied to high-speed motors, very easy to batch failure, but also the core entry point for product iteration and optimization. First, high-frequency corona breakdown: conventional insulating varnish film without nano-modified fillers, high-frequency pulse rapid corona pulverization, triggering turn-to-turn short-circuit, motor shutdown; second, high-frequency loss of overheating: a single thick conductor round wire high-frequency skin effect is serious, the temperature rise in the windings exceeds the standard, accelerating thermal aging of the insulation; third, vibration wear and tear loss: conventional varnish film adhesion is weak, high-frequency electromagnetic vibration of the varnish film abrasion, copper short circuit; fourth, high temperature Thermal cracking: 155 ℃ conventional heat-resistant wire long-term high-temperature operation of the paint film embrittlement, delamination off; Fifth, process adaptation defects: ordinary wire bending toughness is poor, high-speed motor micro-slot precision winding, hairpin molding easy to crack paint.

The above pain points decided: high-speed motor prohibit the use of ordinary enameled aluminum magnet wire, conventional round wire, ordinary polyester enameled wire, must be matched with customized high-speed special winding wire products.

High-speed motor special winding wire product classification

High Temperature and Corona Resistant Round High Speed Enameled Copper Wire

The wire is a standard product for small and medium power industrial high-speed motors. It adopts PEI+PAI double-layer composite insulation, nano alumina corona-resistant modified formula, and 99.95% high purity enameled copper magnet wire for conductor, with a temperature resistance level of 220°C. The product optimizes the denseness of the enamel film and the corona-resistant formula, and is suitable for high speed motors. The product optimizes the denseness and flexibility of the paint film, which is suitable for precision automatic high-speed winding equipment; the modified insulating layer greatly improves the onset voltage of partial discharge, which is suitable for medium and high frequency inverter conditions; the conductor grain annealing optimization reduces the high-frequency eddy current loss. Product positioning: High-speed fans, high-speed spindles, small industrial high-speed motors, general-purpose wires, cost-effective and balanced, mature mass production.

Rectangular Flat Winding Wire High-speed Specialized Flat Wire

Rectangular enameled wire is a rectangular winding wire developed for EV ultra-high-speed drive motors (20,000rpm~30,000rpm), and it is also the main product of high-end high-speed motors. rectangular enameled wire adopts ultra-thin composite corona-resistant insulation, optimized conductor width-to-thickness ratio, weakened neighborhood effect in the slot, and lowered AC loss in high-speed working condition; the slot fullness rate is increased to more than 68%, and the heat dissipation efficiency is greatly improved, which reduces AC loss in high-speed working condition. The heat dissipation efficiency is greatly improved to alleviate the problem of high-speed heating; the paint film is resistant to oil and hydrolysis, suitable for automotive oil-cooled high-speed motors; suitable for Hairpin hairpin windings molded in one piece, with a strong structural rigidity, resistance to ultra-high centrifugal vibration, and elimination of winding loosening and wear. The product is suitable for 800V high voltage platform car with ultra-high speed main drive motor.

Self-bonding high speed anti-vibration winding wire

Relying on the structure of self-bonding magnet wire, the outer layer has its own self-adhesive bonding layer, which does not need to be dipped into paint and tied, and the coil is cured and molded independently under high-speed operation. The overall structure is integrated, which greatly reduces the amplitude of high-frequency vibration and lowers NVH noise and paint friction loss. It is suitable for miniature high-speed motors and high-speed servo motors, simplifying the back-end paint dipping process, and improving the mass production efficiency and operational stability of high-speed motors.

High-speed motor winding line insulation system product selection criteria

Optimized production process for high speed winding wire

In view of the characteristics of high-speed motor wire, matching the exclusive mass production process to ensure product performance. First, low-tension precision winding process, to avoid high-speed special wire film stretching damage, internal stress residue; Second, rectangular flat wire rounded corner precision molding process, suitable for high-speed motor narrow slot structure, bending insulation does not crack; Third, high-voltage and high-speed motor supporting VPI vacuum pressure immersion paint, so that the winding integrated curing, enhance the overall resistance to centrifugal, anti-vibration capabilities; Fourth, the wire factory strictly control the film thickness, pinhole, size tolerance Fourth, the wire factory strictly control the thickness of paint film, pinholes, dimensional tolerances, to ensure that the electric field of high-speed windings uniform distribution, to eliminate the concentration of local electric field.

High-speed motors winding wire is the core material for the efficient, reliable and long-life operation of ultra-high-speed motors. Different from conventional general-purpose electromagnetic wires, it is optimized around the four core product requirements of high-frequency loss, high-temperature heat resistance, vibration and abrasion resistance, and resistance to impulse discharging, to complete the special formula and structure.

Combined with the speed range, cooling mode, voltage platform to accurately match the round corona-resistant copper wire, rectangular high-speed flat wire, high-frequency Leeds wire, self-adhesive vibration-resistant winding wire four major product systems, circumventing the defects of the aluminum wire, copper-clad aluminum wire, ordinary insulated wire applications, can be a comprehensive solution to the industrial high-speed spindles, high-speed fans, EV ultra-high-speed drive motors all the scenes of the failure of the winding problem, for high-speed motors miniaturization, high-efficiency, ultra-long durability, provide standardized wire product solutions for mass production. Provide standardized wire product solutions for the miniaturization, high efficiency and long durability of high-speed motors for mass production.