Z Series Medium Speed Generator

1) Technical Features

Insulation and Protection

The standard insulation system of low voltage generator is class H. The standard insulation system of Medium/high voltage medium speed generator is F class while H class is optional. Adopting high grade insulation paint and advanced impregnating tehnology with multiple layer insulation protection to the stator & rotor assembly, it fully ensure the generator can withstand harsh environment conditions.

Patent Stator Winding Structure (SWS) of Low Voltage Generator:

Enhance the inter-phase insulation strength at the end of winding to protect any short circuit problem among each phase. Enhance the mechanical strength at the end of winding to effectively prevent and withstand the deformation at the end of stator caused by sudden load or short circuit.

Patent Rotor Insulation Structure (RIS) of Low Voltage Generator:

Patent triple insulated structure of rotor coil can effectively improve the rotor turn to turn and interlayer insulation, accordingly the damp-proof and anti-corrosion ability, the life span, reliability and environment adaptability of generators is also substantially improved.

Stator of High Voltage Generator:

Class F stator coil is wrapped with class F epoxy mica tape and mould pressed. Class H stator coil is operated with the mature class H insulation technology and imprenated in VPI (vacuum pressure impregnating) system. Both class F and class H stator coil are processed with anti-corona treatment. Meantime, the stator coil is designed with skewed slot structure to effectively reduce harmonic wave. Enhance the mechanical strength on the end of stator winding to effectively prevent and withstand the deformation on the end of stator caused by the sudden load or short circuit.

Rotor of High Voltage Generator:

Triple insulated structure of the rotor coil can effectively improve the rotor turn to turn and interlayer insulation, the damp-proof and anti-corrosion ability. It will enhance the mechanical strength on the end of the winding to prevent the rotor winding from deforming under high rotation speed. Accordingly, the lifespan, reliability and environment adaptability of generator is also substantially improved. The rotating rectifier is designed as bi-section structure which is convenient for maintenance and do not require any knock down on the generator.

Winding

2/3 winding pitch for low voltage and 5/6 or 2/3 winding pitch for medium/high voltage medium speed generator can decrease the content of voltage harmonic wave and is suitable for non-linear load application.

Rated Voltage, Frequency and Parallel Operation

50Hz: 220V - 11kV

60Hz: 127V - 13.8kV

The parallel operation is available for the same type generator.

Excitation System

The standard configuration of low voltage medium speed generator is self-excited brushless excitation system with steady voltage regulation ≤±1%; PMG and digital voltage regulator: the accuracy of steady voltage regulation ≤± 0.5%.

The standard configuration of medium/high voltage medium speed generator is PMG and digital voltage regulator , which can enhance the anti-interference capacity and voltage transient performance under large load change, the accuracy of steady voltage < ± 0.5%.

Manual Voltage Regulation

The voltage regulation range of the internal potentiometer of the equipped voltage regulator is >±5%. The output voltage range can be controlled by an external potentiometer purchased by customer himself or an external direct current voltage.

Harmonic Wave and Interference

THD<3%，TIF <50 ，THF <2%

Three Phase Short Circuit Current

When configured with PMG or auxiliary winding, the three phrase short circuit current is more than three times the rated current (>300% In, 10s). The standard configuration of medium/high voltage medium speed generator is PMG. The low voltage medium speed generator EG225 and above can be configured with PMG upon request.

Transient Voltage Regulation

Under sudden load and unload condition, the transient voltage regulation range is between -15% to +20%, and the recovery time ≤1.0s.

Rotor Dynamic Balancing

All rotors have been dynamically balanced at factory before delivery and the accuracy of dynamic balancing conforms to ISO1940.

Bearing

The none drive end (NDE) of low voltage medium speed generator EG355 and below is configured with sealed self-lubricating bearing, while the rest models are configured with regreaseable bearing. The maximum over speed > 2250 rpm;

High voltage medium speed generator is configured with long lifespan rolling bearing which is convenient for the regreasing.

Over Load

Over load allowance: 10% (1 hour in every 1