This Technical Specification IEC/TS 62578 describes the operation conditions and typical characteristics of active infeed converters (AIC) of all technologies and topologies which can be connected between the electrical power supply network (lines) a.c. side and a constant current or voltage type d.c. side and which can convert electrical power (active and reactive) in both directions (generative or regenerative). Applications with active infeed converters are commonly used with the d.c. sides of adjustable speed power drive systems (PDS), uninterruptible power systems (UPS), active filters, photovoltaic systems, wind turbine systems, battery backed power management systems etc. of all voltages and power ratings. Active infeed converters are generally connected between the electrical power supply network (a.c. side) and a current or voltage d.c. side, with the objective to avoid emitting low frequency harmonics (e.g. less than 1 kHz) by synthesizing a sinusoidal a.c. current. Some of them can additionally compensate the pre-existing harmonic distortion of a given supply side voltage. They are moreover able to control the power factor of a power supply network section by moving the electrical power (active and reactive) in both directions (generative or regenerative), which enables energy saving in the system and stabilizes the power supply voltage or enables coupling of renewable energy sources or electrical energy storage devices to the supply.
A practical and analytical approach for emission values for AICs in power supply networks is given, which is based on the latest results for line impedance values between 2 kHz and 9 kHz and withstand capability of capacitors connected directly to the supply. This results in design recommendations for emission values below 150 kHz.