TDK Corporation has released a new series of EPCOS LCL filters for recuperative frequency converter systems.
Consisting of a power choke, a capacitor bank with damping resistors and a robust choke, these new high-performance filters satisfy IEC / TS 62578 recommendations for EMI emissions between 9 kHz and 150 kHz. In combination with in combination with a recuperative frequency converter system, the new LCL filters can significantly reduce the line-side harmonics to less than 5 percent. Thanks to the integration of the choke in the LCL filter, the recuperative unit can also be operated as a boost converter for higher DC link voltages.
TDK’s new LCL filters are designed for rated currents of 16 A, 66 A, 200 A, and 400 A at a rated voltage of 520 V. The two smaller versions (16 A and 66 A) are accommodated on a mounting plate for ease of use while the larger versions (200A and 400A) consist of two units: a separate storage choke and a mounting plate with power choke and capacitor bank. The filters are designed for clock frequencies of 7 kHz to 16 kHz for the feedback module and 4 kHz to 16 kHz for the motor-side frequency converter module. In addition, they are designed for a maximum motor lead length of 150 m or 6 axles and a maximum motor frequency of 100 Hz. Damping resistors integrated in the module prevent the development of natural oscillations. The filters are designed as open modules with convection cooling to protection class IP 00 (corresponding to IEC 60529 2001).