Research On Related Technologies Of Re-frequency High-voltage Pulse Power Supply For Ballast Water Treatment

The ships’ ballast water has caused many hazards. As a new and efficient ballast watertreatment technology, there are many unsolved problems for pulse arc electrohydraulicdischarge (PAED) technology, including the development of the pulse power supply.Efficient, fast, reliable re-frequency high-voltage pulse power supply is the key for theindustrialization promotion of ship ballast water treatment by PAED. In this paper, relatedtechnologies of re-frequency high-voltage pulse power supply for ballast water treatment isstudied, which includes: load characteristics analysis of the power, parameter determination,topology selection, designing a single-phase series resonance constant current chargingsystem for a80uF capacitance which requires a10Hz repetition frequency and2.5kVcharging voltage. Based on theoretical and experimental analysis on the four alternativesswitch, the two of them are selected as comparatively ideal discharging switches for powersupply.Development process of PAED is analyzed, load characteristics and outputcharacteristics of the power supply is obtained. Under the premise that stable PAED isensured, an appropriate increase in the discharge energy can lead to better treatment effect.Considering composite load characteristics and PAED requirements, main capacitor80μFand charging voltage of1-5kV is selected for the pulse power. Taking compatibility of thepower supply miniaturization and marine power distribution system into account,frequency of1-10Hz and rated power of1-10kW is selected for the pulse power.The three capacitor charging system: constant voltage charging, power frequencyresonant charging, high-frequency resonant constant current charging is analyzed andcalculated, series resonant constant current charging is selected as the first choice forre-frequency high-voltage pulse power supply for ballast water treatment. A single-phaseseries resonance constant current charging system for a80uF capacitance which requires a10HZ repetition frequency and2.5kV charging voltage is designed.In the paper, special requirements of discharge switch for re-frequency high-voltagepulse power supply for ballast water treatment is analyzed. Four alternative switch: gasspark switch, triggered vacuum switch, pseudo-spark switch and thyristor switch is selected. Respectively, their working mechanism are analyzed, their adaptability in PAED circuit aretested, their working performance in PAED treating ballast water are test, the necessity ofserial protected inductance for thyristor switch to be applied in PAED is analyzedpseudo-spark switch and thyristor switch are selected as comparatively ideal dischargingswitches for power supply.