35kv Class Ovdt Dry Type Distribution Transformer

1, Low loss, low noise, low partial discharge, high reliability, great overload capacity and high heat-resistance.

1.Self-extinguishing and inflaming retarding, fire-proof and explosion-proof, pollution-free and no toxic gas being generated.

2.Excellent damp-proof performance, capable of working under 100% relative humidity and other harsh conditions, with no damp-removing measures needed.

3.Not sensitive to dust and environment pollutions. Excellent structure design realizes chap-free features and high heat-dispersion performance.

4.Great overload capability, capable of operating continuously under 120% overload conditions and in case of air forced cooling, operating continuously under150% overload conditions.

5.Nice appearance, small-size, less installation space occupation and low engineering cost.

6.Each performance index and technical specification excels those specified in China GB, international IEC or industrial standards.

The core is manufactured with high quality cold rolled grain-oriented silicon steel of high magnetic conductivity. 45° mitring and 5-steps overlapping structure is adopted for the core design, thus to greatly reduce no-load loss and no-load current. To precisely calculate resonance frequency and intensity and avoid cavity resonance generated by the core structure during operation, simulation analysis is carried out for core mould design. Flexible connections are made between core and coils, core and bogie. With these measures adopted, the noise level is reduced by 10~15dB compared with the international standard.

HV windings are manufactured with the NOMEX paper-covered oxygen-free and high-conductivity copper conductor, with continuous disk-winding structure adopted. Within the windings is the high-strength insulation cylinder support. And between the insulation cylinder and the disk winding are the insulation pads, thus to form an axial air passage within the windings. Between the disks are the high-strength insulation pad, thus to form radial air passage within the windings. This structure greatly improves windings' heat-dispersion performance and mechanical strength, thus finally to improve product's operation reliability. During winding design, full consideration is given to the electric field characteristics by adopting optimum structure for improving the electric field distribution and reducing the local partial discharge while improving the product's anti-lightning impulse capability.

LVwinding (with the rated power equal to or higher than 400kVA) is manufactured with high quality foil conductor, resulting in excellent ampere-turn balance, low transverse magnetic flux leakage and higher anti-short circuit capability. By designing reasonable air conduit in the windings to increase the heat-dispersion surface, transformer's temperature rise is effectively controlled and the overload capacity is greatly improved.

Attractive and wearing-resistant protective enclosures are available to provide additional protection to transformer, and the protection level could be IP20, IP23 or higher. The material is stainless steel plate, aluminum alloy plate and other suitable materials. IP20 enclosure provides protection against the entrance of foreign objects with diameter exceeding 12mm and could withstand accidental shock. IP23 enclosure, in addition to functions of IP20 enclosure, also provides protection against rainfall at a vertical angle of less than 60°. But the IP23 enclosure will reduce transformer's cooling capacity by about 5%~10%, therefore this must be taken into account when selecting enclosure for the transformer. Cable support is supplied for HV(LV) incoming (outgoing) connections from bottom of enclosure.

-- IEC60076-11, DIN42523

-- Certificate: ISO9001: 2000, ISO14001: 1996, CE