This master's thesis presents the structure, operation, design and production of a single-phase series active power filter (later referred to as SAPF), whose purpose is the correction of the supply voltage between the power network and the load.
In the initial part, a basic overview of active power filters is given, with an emphasis on the operation of the active serial filter, which consists of the input and the output transistor bridge. The operation and topology of the two bridges are described, as well as the regulation of their output quantities.
In the central part of the thesis guidelines are given for the design of such a device, which were considered during the production process. While describing the design stage, the basic operation of the entire device is also discussed through a simplified block scheme. Among other things, the individual circuit segments are explained in detail, as are the various modifications that occurred during the manufacture and testing of the device.
This is followed by a detailed description of the program code that is executed on the microcontroller. Basic architecture consists of an initialization, endless loop, protection interrupt and periodic interrupt. All parts are thoroughly described with special detail on how the program executes at special event (turn on, turn off, fault sense).
Finally, the results of the measurements of the device during operation are presented, in order to prove the filter works according to the desired expectations. We focused on voltage and current measurements in the time domain, both in idle state and with the load on the output, as well as on voltage measurements in the frequency domain, whereby the efficiency of the filter was also represented through the THD factor.