Apparatus and method for providing ignition to a turbine engine

In an ignition system using an igniter plug for igniting fuel of an engine, an ignition sequence that minimizes the wear on the igniter plug comprising the steps of:

• applying power to the ignition system from a power source;
• automatically generating repeated spark discharges at the igniter plug in response to the application of power to the ignitions system at a first average rate and for a predetermined time period that best assures combustion of the fuel while also limiting the exposure of the system to high thermal stress caused by the first average rate of sparks;
• automatically continuing the repeating of spark discharges at the igniter plug after the predetermined time period at a second average rate which is less than the first period at a second average rate which is less than the first average rate of spark discharges until power is removed from the ignition system or the sequence is restarted;
• detecting the electrical characteristics of the sparks and forming a diagnostic signal indicative thereof;
• and
• providing the diagnostic signal to a diagnostic unit.

In an ignition system, a method for igniting fuel of a turbine engine and maintaining ignition of the fuel, the method comprising the steps of:

• (a) applying a power source to the ignition system;
• (b) pumping energy from the power source into an energy storage device at a substantially constant rate;
• (c) discharging the energy from the energy storage device into a spark gap for igniting the fuel of the turbine engine;
• (d) automatically repeating steps b and c in order to create pump-discharge cycles at a first average repetition rate for a predetermined time interval in response to the application of power to the system, wherein the first average repetition rate and predetermined time interval are selected to ensure ignition of the turbine engine;
• (e) continuing to repeat steps b and c in order to create pump-discharge cycles at a second average repetition rate lower than the first average repetition rate after the predetermine time interval has expired and until the power source is removed from the ignition system;
• and
• (f) determining the first and second average repetition rates of the pump-discharge cycles by inserting variable delays between an occurrence of a discharge event in one cycle and a beginning of a pumping event in a following cycle.

In an ignition system using an igniter plug for igniting fuel of an engine, an ignition sequence comprising the steps of:

• (a) applying energy to the ignition system;
• (b) pumping the energy into an energy storage device;
• (c) discharging the energy from the energy storage device into the igniter plug for generating a spark intended to ignite the fuel of the engine;
• (d) repeating steps b and c in order to create cycles of pumping and discharging such that the repeating includes the step of:
• (e) delaying the initiation of pumping of energy into the energy storage device after the discharging of the device in a previous cycle such that a sequence of cycles initiated after application of energy to the ignition system causes the generation of sparks at a first average rate for a predetermined time period intended to ensure ignition of the fuel and at a second average rate thereafter, which is less than the first rate and intended to maintain ignition.