一、Overview

1.1 Purpose and scope of application

The rectifier transformer (hereinafter referred to as transformer) is a dry transformer that mainly applies to the urban trolleybus traction substation.

1.2  Model composition and its meaning

Rated input voltage

Rated power

Design Number

Three-phase transformer

Apply to the traction substation

Rectifier transformer 

1000KVA/10000V Main technical parameters of rectifier transformer

1.3 Product parameters 

 Table 1

1.4  Application environment and operating condition

1.4.1  

The transformer is applied to places free from harmful gases that may corrode metal and compromise insulation, gas, coal dust or other similar places.

1.4.2 The elevated altitude shall not exceed 1000m.

1.4.3 The temperature for the surrounded medium shall not exceed ＋40℃ and lower than －20℃.

1.4.4The relative humidity of the surrounded medium shall not exceed 95%(when the air temperature is 20℃±5℃).

1.4.5 It shall be kept at places free from water and other liquids.

1.4.6 It shall be kept at places free from severe vibration and impact.

1.4.7 The horizontal slope of the installation place shall not exceed 5%.

1.4.8 ：The requirements to the line side power supply:

 a) Phase number and frequency:

       b) The fluctuation range of voltage magnitude: the continuous fluctuation shall not exceed 10% of the rated value.

       c) The variation range of frequency; it shall not exceed 2% of the rated value.

       d)

The degree of symmetry: the negative sequence or zero sequence component shall not exceed 5% of the positive sequence component.

I. The design principle and structural features of the transformer

2．1  The design principle of the transformer

1min， As the transformer is mainly applied to the traction substation, therefore, it must satisfy the overload requirement of its rectifier, which means that it can continue to operate for 100% of rated output current, and it can operate continuously for 2h for 150% of the rated output current and it can operate continuously for 1h for 200% of the rated output current.

2.2  The installation of transformer

It should be separately installed indoor.

2.3 The technical performance of the transformer

2.3.1 Rated capacity: Please refer to table 1;

2.3.2 The rated voltage on line side and on valve side: Please refer to table 1;

 2.3.3 The tapping mode: A tap is available at the position of ±2*2.5﹪

2.3.4 Grade of load: V

2.3.5 Insulation grade: F

2.3.6 Ultimate temperature rise: 80K

2.3.7Type of cooling: Natural air cooling.

2.3.81min；Insulation level: 6kV voltage class and withstand power frequency voltage is 20kV, duration 1min

2.3.9 Short-circuit impedance: Please refer to table 1;

2.3.10 The no-load voltage ratio measured shall not be greater than ±1﹪ of the specified value;

2.3.11 The no-load loss, load loss and the no-load current shall conform to the stipulation of GB/T 10228.

2.3.12 DC:600V； The DC rated output voltage:

2.3.13 DC1250A； The DC rated output current:

2.3.14 Digital temperature controller is available for the product

2.3.15  Operating mode: continuous

2.3.16  Cooling mode: self-cooling

2.3.17 Without outer shell.

II. The installation and operation of transformer

3.1 Please make sure that the winding and the iron core of the transformer shall be secured and make sure that there is no damage of its wire insulation. Please make sure that the screws of upper and lower clamping plate shall be secured, please eliminate any abnormal condition.

3.2 Before connecting to the power supply, please use the ground bolt of the transformer to ground it well. Then, use a tramegger to measure the insulation resistance of three windings to the iron core and the primary and secondary insulation resistance of each winding. The resistance of 6kV voltage shall be no less than 10 MΩ and shall be no less than 1MΩ for 1KV voltage or lower voltage.

3.3  Please connect the wire for transformer to the power supply for once and connect the wire for transformer to the rectifier for twice according to the instruction on the label of the transformer. Please do not switch primary and secondary winding, otherwise, the transformer and rectifier may be severely damaged.

3.4 Please use voltmeter to measure the three-phase voltage twice once electrifying and make sure that the degree of symmetry shall not be greater than 5%. Please make sure that the voltage value shall meet the requirements of the output of rectifier, if not, please adjust it through tapping point.

3.5 Please pay attention to the temperature rise of the winding for the first operation, if the temperature is too high, please shut down the power supply for inspection.

III. Fault analysis and troubleshooting

IV. Maintenance

5.1The dry transformer is a product of high reliability and it normally can operate well with less fault. For overhaul and recondition, please observe whether there are any abnormal conditions of the windings or measure the insulation resistance. Please use clamp meter to measure the three-phase input current on the line side when re-electrifying, please process accordingly for any abnormal conditions.  

5.2 The storage environment and re-boot requirements

Please keep the transformer in places are dry, free from rain and of good ventilation if not use it in a long time. Please proceed according to the third point to install to use.