A power supply system for generating high-voltage pulses superimposed on a DC base voltage suitable for powering an electrostatic precipitator, said power supply system comprising: an AC supply circuit configured to generate a first AC supply voltage and a second AC supply voltage; a DC supply circuit connectable between said AC supply circuit and said electrostatic precipitator, said DC supply circuit comprising a first transformer and a first rectifier circuit for transforming and converting said first AC supply voltage to said DC base voltage; a pulse supply circuit connectable between said AC supply circuit and said electrostatic precipitator, said pulse supply circuit comprising: a second transformer and a second rectifier circuit for transforming and converting said second AC supply voltage to a DC pulse supply voltage in the range 40 kV to 120 kV, sufficient to generate said high-voltage pulses; a pulse forming circuit (12; 12') connectable between said second rectifier circuit and said electrostatic precipitator, said pulse forming circuit being configured to generate said high-voltage pulses without additional voltage transformation, said pulse forming circuit including a high voltage switching circuit comprising an anti-parallel coupling of a chain of diodes and a chain of thyristors; wherein said AC supply circuit is configured such that a frequency of each of said first AC supply voltage and said second AC supply voltage are in the range of 100 Hz to 5000 Hz. an AC supply circuit configured to generate a first AC supply voltage and a second AC supply voltage; a DC supply circuit connectable between said AC supply circuit and said electrostatic precipitator, said DC supply circuit comprising a first transformer and a first rectifier circuit for transforming and converting said first AC supply voltage to said DC base voltage; a pulse supply circuit connectable between said AC supply circuit and said electrostatic precipitator, said pulse supply circuit comprising: a second transformer and a second rectifier circuit for transforming and converting said second AC supply voltage to a DC pulse supply voltage in the range 40 kV to 120 kV, sufficient to generate said high-voltage pulses; a pulse forming circuit (12; 12') connectable between said second rectifier circuit and said electrostatic precipitator, said pulse forming circuit being configured to generate said high-voltage pulses without additional voltage transformation, said pulse forming circuit including a high voltage switching circuit comprising an anti-parallel coupling of a chain of diodes and a chain of thyristors; a second transformer and a second rectifier circuit for transforming and converting said second AC supply voltage to a DC pulse supply voltage in the range 40 kV to 120 kV, sufficient to generate said high-voltage pulses; a pulse forming circuit (12; 12') connectable between said second rectifier circuit and said electrostatic precipitator, said pulse forming circuit being configured to generate said high-voltage pulses without additional voltage transformation, said pulse forming circuit including a high voltage switching circuit comprising an anti-parallel coupling of a chain of diodes and a chain of thyristors; wherein said AC supply circuit is configured such that a frequency of each of said first AC supply voltage and said second AC supply voltage are in the range of 100 Hz to 5000 Hz.