## 4 Discussion  
The proposed high-voltage power supply topology was designed for capacitive types of load. This feature makes it suitable to supply non-thermal plasma reactors of various constructions. While most high-voltage power supplies are designed to supply only one type of load with a specified capacity [8; 9], the proposed topology is appropriate for both DBD and PCD plasma reactors, and for a wide range of reactor capacities. The construction is fully resonant, with all the used semiconductor switches being commutated in ZCS (zero current switching) mode in order to limit switching loss. SiC technology was used to increase the efficiency of consecutive converters. Usually, in the case of high-voltage pulsed converters, control of semiconductor switches demands high precision and additional feedback (e.g., voltage or current sensing circuits) is often used [20]. An important feature of the proposed converter is loss minimization due to soft switching of power switches regardless of changes in the load, so there is no need to use additional feedbacks and/or additional snubbers or other switch protection circuits. The mentioned feature also significantly simplifies the power supply control algorithms. The resonant capacitor charger unit allows for recharging of the energy storage capacitor with a high efficiency and provides the additional possibility to adjust its final voltage value by regulation of the charging interval number. The efficiency of the charging process was 96%. The presented high-voltage transformer design is scalable to various transformer winding ratios and magnetic coupling ratios through proper selection of the number and arrangement of magnetic cores used in the design. The proposed transformer construction allows for obtaining low magnetic coupling between transformer windings along with a small external magnetic field. The energy conversion efficiency of the constructed transformer prototype was similar or higher compared to similar constructions [14; 21], but the EMC (electromagnetic compatibility) was significantly increased. The disadvantage of the proposed topology is the high current amplitude on the primary side of the transformer, however, this a typical feature of this group of converters [14]. The output pulse was shaped by resonance of the high-voltage transformer leakage inductances and the capacitance of the load. In the case of small capacitance reactors (e.g., a PCD reactor with wide discharge gaps) additional capacitance, C\({}_{3}\), is connected in parallel to the load, and helps to stabilize the resonance conditions. In the case of reactors exhibiting big capacitance (e.g., large area DBD reactors) capacitance C\({}_{3}\) can be omitted, and only the capacity of the reactor will affect the resonance frequency. To maximize the efficiency, the reactor capacitance should be taken into account in converter design. The power delivered to the load can be regulated by both the regulation of output pulse amplitudes and their repetition frequency. The maximum frequency of output pulse generation of the built prototype was 2 kHz, and the maximum voltage amplitude was 20 kV for 400 V of input  
Figure 14: The measured output voltage and current waveforms for PCD reactor discharge and calculated power and energy applied to the load. DC voltage bus. The efficiency of the output pulse generation process for the pulse shaping unit was 71%, which is a good result considering that the applied high-voltage transformer had a large number of secondary windings and several magnetic cores. The output pulse shaping unit utilizes the principles of a Tesla coil transformer and the natural resonance of the circuit created by the transformer's parasitic inductances and a capacitive load. The shape of the output voltage pulse was asymmetric, and its average value was equal to zero, which is beneficial for DBD reactors.