Loop feed 3 phase pad mount distribution transformer is applicable to various places that require three-phase power distribution, such as residential buildings, commercial buildings, industrial parks, energy storage power stations, electric vehicle charging stations, etc., especially in occasions with high requirements for power supply reliability.
Introduction:
Loop feed 3 phase pad mount distribution transformer is an important device specially designed for underground power distribution systems, mainly used in places such as urban power grids and industrial parks that require highly reliable power supply. This type of transformer is installed on an outdoor ground base and can achieve ring network power supply, enhancing the reliability and flexibility of power supply.
Structural design:
Integrated design:
This type of transformer integrates the transformer body, load switch, protective fuse and other equipment in a unified design. The windings, core, high-voltage load switch and protective fuse are all installed in the same oil-filled oil tank, without relatively independent high and low voltage switch cabinets.
Reasonable layout: The front part is the high and low pressure operation area, including high and low pressure bushings, load switches, no-load tap changers, insertable fuses, pressure relief valves, thermometers, oil level gauges, oil injection holes, oil drain valves, etc. The rear part houses the fuel tank and radiator.
Working principle:
For a three-phase transformer powered by a ring network, there are usually six high-voltage bushings on its high-voltage side. It can achieve a dual power supply configuration. When one power supply fails, the other can continue to supply power to the transformer, thus ensuring continuous power supply to the load and improving the reliability of power supply. A three-phase transformer converts the three-phase voltage into step-up or step-down through three sets of primary and secondary windings to meet the requirements of different loads.
Testing and Experimentation:
1. Routine test
– Insulation resistance test: Use a 2500V megohmmeter to measure the insulation resistance on the high-voltage side to ground. The standard value should be ≥1000MΩ.
– Ratio test: Verify the turns ratio of the high-voltage side to the low-voltage side through a ratio tester. The error should be controlled within ±0.5%.
– DC resistance test: Measure the DC resistance of the winding. The three-phase unbalance rate should be less than 2%.
2. Type test
– Temperature rise test: When operating under rated load until thermal stability is achieved, the temperature rise of the top layer oil must not exceed 55K.
Short-circuit withstand capacity test: Simulate the impact of short-circuit current to verify mechanical strength and thermal stability. The test current is 25 times the rated current (lasting for 2 seconds).
3. Special tests
Partial discharge test: At 1.3 times the rated voltage, the partial discharge quantity should be less than 10pC.
– Noise test: The noise during no-load operation should be ≤65dB (A-weighted, measurement distance 1 meter).
Advantage:
1.High reliability: The ring network design ensures uninterrupted power supply.
2.Space saving: Compact design is suitable for areas with limited space.
3.High safety: The fully enclosed design reduces the risk of electric shock.
4.Easy maintenance: Ground installation makes it convenient for inspection and repair.
5.Aesthetics: Hidden on the ground, it does not affect the urban landscape.