Common mode inductive charging pile solution

The DC charging pile power module converts three-phase 380V AC power into 750V DC voltage. It is a power supply device that is fixedly installed outside the electric vehicle and connected to the AC grid to provide high-power DC power for the power battery of the electric vehicle; the front stage usually uses three-phase PFC circuit, DCDC module of the latter stage usually adopts three-level LLC circuit for power regulation, and the whole power module includes PFC inductor, resonant inductor, transformer and EMI filter inductor.

1. Charging pile high-frequency transformer:

Compared with the traditional transformer, the high-frequency transformer of the charging pile described has a higher space utilization rate. The magnetic core adopts the structure of ferrite low-loss PC95 material EE65, which achieves the purpose of high power and low magnetic density; the wire package adopts multi-strand twisting The film-covered copper wire and copper foil are divided into primary and secondary windings. The main feature of the multi-strand film-covered wire is good insulation, and it is twisted by different numbers of thin copper wires to solve the problem of skin effect in the flow; because EE65 size and structure problem, the use of copper foil with smaller thickness and larger width also meets the problems of better flow and smaller current density, ensuring the product's efficiency and heat dissipation are good.



2. Charging pile resonant inductance:

The main characteristics of the resonant inductor of the charging pile are that the magnetic core is made of ferrite low-loss PC95 sheet material, and the magnetic core itself is stacked to form a magnetic column. There are segmented air gaps between each sheet, and the size of each segment is 0.17mm. Below, the range of the cutting magnetic field becomes smaller when working, thereby effectively reducing the iron loss of the product; the winding uses multi-strand twisted film-clad copper wire, which has good insulation effect, and is made of multi-strand thin copper wires, which solves the problem of copper The problem of loss; compared with the traditional resonant inductor, the resonant inductor of the charging pile has low loss, higher efficiency, good current flow capacity, and strong DC superposition resistance.



3. PFC inductor

The PFC inductor adopts alloy powder core iron silicon/silicon aluminum with good DC bias resistance as the main body, which can stably maintain the inductance value under a specific current during work, effectively eliminate subtle clutter, and play a very good power Factor correction effect, the main characteristics are strong resistance to DC bias and high space utilization, and it is one of the indispensable and important devices for current charging pile projects.




4. EMI filter inductor

EMI filter inductors are made of high-conductivity nanocrystalline magnetic rings. Compared with traditional manganese-zinc ferrite magnetic rings, nanocrystalline has more excellent high magnetic permeability, which can achieve higher inductance and play a better role. To filter out clutter, the shell of the nanocrystalline magnetic ring also has a better insulation and voltage resistance effect than the layer of the ferrite core. Its characteristics are mainly high inductance, good insulation withstand voltage performance, and high reliability.