Automatic back corona detection and protection system

A method for optimizing the intermittent energization type of operation of an electrostatic dust precipitator to substantially prevent back corona, said method comprising the steps of:

• a. energizing said precipitator with voltage pulses at a predetermined minimum pulse repetition rate;
• b. incrementally decreasing the time between said voltage pulses by a predetermined amount;
• c. monitoring a minimum peak voltage value during said time between said voltage pulses;
• d. repeating steps b and c until a predetermined change in said minimum peak voltage value is detected;
• and,
• e. incrementally increasing the time between said voltage pulses by a predetermined amount.

An automatic back corona detection and protection system for controlling an electrostatic dust precipitator, comprising:

• a. means for monitoring voltage and current parameters of a high voltage transformer/rectifier of said electrostatic dust precipitator;
• b. first means for detecting a back corona condition coupled to said monitoring means, said first detecting means identifying to said control means an onset of a back corona condition responsive to a lack of decrease in a minimum peak of voltage value of an output voltage of said high voltage transformer/rectifier coincident with an increase in an output current value of said high voltage transformer/rectifier as said input power to said high voltage transformer/rectifier is increased;
• c. second means for detecting a back corona condition coupled to said monitoring means, said second detecting means identifying to said control means an onset of a back corona condition responsive to a increase in said minimum peak voltage value of said output voltage of said high voltage transformer/rectifier as said input power to said high voltage transformer/rectifier is increased;
• d. control means coupled to both said first and second back corona detecting means for controlling input power to said high voltage transformer/rectifier responsive to detection of a back corona condition by either said first or second detecting means;
• and,
• e. timing means coupled to said control means for periodic enablement of both said first and second detecting means, whereby operating conditions which are conducive to back corona conditions are automatically periodically determined and used to limit said input power to substantially prevent back corona in said precipitator.