Waterproof transformer for photovoltaic power generation system

technical parameter

Product overview

This series of isolation transformers have the advantages of anti-interference, fire prevention, moisture proof, safety and security, energy saving and convenient maintenance.

Solar energy has attracted more and more attention due to its advantages of pollution-free, noise-free, and wide distribution. At present, most photovoltaic grid-connected power generation systems contain isolation transformers, and there is a leakage current problem in photovoltaic power generation systems without isolation transformers.

Product features

(1) Our company uses high-quality materials and advanced technology to produce SG and DG series three-phase and single-phase dry isolation transformers. This series of transformers not only have the function of voltage transformation in the power grid, but also isolate the power grid to the equipment. The first harmonic protects the heat generated by the machine and reduces the life of the end-of-line materials. It is especially suitable for imported equipment (270V input → 380V output, 315V input-output 380V) between 1KVA-1000KVA and used for bypass of photovoltaic inverter power supply.

(2) Due to the particularity of photovoltaic power generation, large-scale investment in photovoltaic grid-connected systems is bound to bring hidden dangers to the feasibility and stability of the grid, such as harmonics, flicker, DC bias, overvoltage, etc. Therefore, it is necessary to study appropriate solutions to solve the above-mentioned problems. A good method is to add an isolation transformer between the grid and the grid-connected inverter to isolate the inverter from the grid. Due to the isolation transformer, the leakage current caused by the potential floating caused by the switching of the inverter power device and the small DC current generated by the inverter in the control are effectively isolated and suppressed. Thereby it will not have an adverse effect on the power grid.

The role of isolation transformer

The isolation transformer is very important in the single-stage photovoltaic grid-connected inverter system. Its performance is not only related to the efficiency and heat generation of the transformer itself, but also determines the technical performance of the entire converter, and even leads to the damage and inversion of the power tube.Failed. At this time, the isolation transformer's voltage conversion is no longer the only function of the isolation transformer, it also has many other important functions.

(1) Electrical isolation: Use a transformer to achieve electrical isolation between the photovoltaic power supply and the grid.

(2) Prevent the self-clearing component of current from being injected into the grid: applying electricity from dry and self-slag will not cause the change of magnetic flux, so the direct-dissolving component of the photovoltaic system

Will not flow into the grid through the isolation transformer.

(3) Anti-interference effect: An isolation transformer with a certain connection mode can eliminate the third and integer multiples of harmonics, and reduce the impact of high-order harmonics and voltage fluctuations on the power grid.

(4) The role of voltage stabilization: When the system fails, it can effectively suppress the harmonic overvoltage and steady-state overvoltage of the photovoltaic inverter system.

Isolation transformer wiring selection: (△Yn and Yn△)

(1) Choose from the perspective of harmonics: △Yn and Yn/△ two solutions can effectively reduce the harmonic content of the grid current.

(2) Comparison from the perspective of suppressing or suppressing the DC component: Both △/Yn and Yn/△ connections are used to produce the DC component, so that the current DC component content is lower, but the A/Yn connection The method is slightly better than the Yn/△ connection method.

(3) The output voltage waveform quality of the △Yn connection method is better than that of the Yn/△ connection method. From the total harmonic distortion rate, it can also be explained that the △/Yn connection method is better than the Yn/△ connection method.