Active Harmonics Filter
AXPERT- i-sine AHF provides 3 phase harmonic current compensation.
Figs. 1 and 2 show the operational principle of the active filter, with which a rectifier load is connected. As shown in fig.1, the active filter is inserted between the load and the source, in parallel to the load. For a six-phase rectifier load, the load current IL appears in a form of rectangular waves, as illustrated in Fig. 2. This can be considered a result of synthesis of the fundamental current IF and the harmonic current IH (Fig. 2).
(IL = IF+IH)
The compensation current IC of the active filter is controlled so that its intensity is the same as that of the above-mentioned IH , and its polarity is just reversed (IC = -IH). As a result, components of harmonic currents contained in the load current are canceled by the effect of active filter, and source current IS remains only to be IF , which is a sinusoidal wave (Fig. 2).
This can be clearly explained by the expression shown below.
IL = IF+IH, IC = -IH
IS = IL+IC = (IF+IH) + (-IH) = IF
AXPERT- i-sine is equipped with a user friendly control panel. Self-explanatory full parameter names, easy navigation of parameters through well organized parameter sets & functional keys, 8-selectable parameters on single screen makes it easy to operate and program.
The optional TFT panel with special white back light offers access to all parameters, waveforms & spectrums for management of both AXPERT- i-sine and system power quality. The graphics TFT display & control panel gives easy access for load, source & AXPERT- i-sine.
- Monitoring of all metering parameters like V, I, F, kVA, P.F., THD
- Control commands & settings
- Waveforms & harmonics spectrum (optional touch screen TFT panel)
- Status & alarms
- Fast Fourier Transform based harmonic compensation
- Operates with closed loop control
- Harmonics attenuation up to 97% at rated current
- Reactive power compensation
- Harmonics compensation with and without PF compensation
- Ability of parallel operation to increase power capacity
- Voltage-independent harmonic current tracking
- Inherent current limiting
- Shunt connection
- Backlit user interface (optional TFT with touch screen)
- Serial monitoring
- Modbus RTU communication compatible
- Advanced programmable digital I/O interface
- Intelligent control algorithm which dynamically changes the switching frequency to optimize the performance
- Programmable selective harmonics elimination
- Best accuracy. Does not require detailed network analysis
- Prevents possible harmonic resonance
- Automatic PF compensation, leading as well as lagging
- Optimum utilization of power capacity
- Adaptive to increase in harmonics current due to additional loads being added
- More immunity to input voltage distortion
- Over load condition is prevented
- Easy for Maintenance
- User-friendly operation
- Remote monitoring can be done
- Facilitates networking ability
- Selective harmonics elimination by digital programming
- Minimum insertion loss resulting in efficient operation
Amtechs Multi functional Active Harmonic Filter can compensate for reactive currents of fundamental waves, harmonic currents etc. It finds applications in various scenarios with combination of its multi-functions.
Intelligent Buildings :OA equipment, air conditioners, lighting, UPS, elevators, pumping facilities
Factories :Crane facilities, press machine, machine tools, high frequency induction heating equipment, inverter-incorporated facilities, printing machines, paper machines
Public facilities and Others :City-water and sewage pumping facilities, harbor crane facilities, crane facilities at waste incineration plants, ropeway hoisting machines, amusement parks etc.
Normally 3-phase large UPS with 6-pulse rectifier feedbacks heavy harmonics current of 30%~40% THD into mains or emergency generator. It can cause line voltage distortion or generator malfunction. i-sine AHF is well adapted to operate with large UPS to perform very low harmonic feedback, generating less than 5%.