Parameter tuning approach for bypass damping filter to suppress subsynchronous resonance in power systems

A parameter tuning method for a bypass damping filter (BDF) to suppress subsynchronous resonance in power systems, comprising the following steps:

• (1) calculating typical frequencies of each torsional mode according to turbine-generator shaft parameters, and supposing a low frequency oscillation mode of the shaft is within a frequency range of 0˜2 Hz;
• (2) choosing a per-unit frequency where negative electrical damping reaches minimum to be fm*, the fm* should be away from the frequency range of low frequency oscillation mode and typical frequencies of the each torsional mode mentioned in Step (1);
• (3) according to the chosen fm* in Step (2), calculating a per-unit capacitance and reactance XBDF at system rated frequency using the equation below:
• X
• BDF
• =
• X
• C
• ⁡
• (
• X
• L
• -
• X
• C
• )
• f
• e
• *
• 2
• ⁢
• X
• L
• -
• X
• C
• -
• X
• C
• f
• e
• *
• =
• 1
• -
• f
• m
• *
• ;
• where XL is a system per-unit reactance at rated frequency, including generator subtransient reactance, line reactance and equivalent reactance of the receiving power grid;
• XC is capacitance of the series capacitor at rated frequency;
• (4) calculating actual physical parameters of a capacitor and a inductor in BDF according to the above-mentioned XBDF in Step (3);
• (5) calculating a minimum value of generator negative electrical damping De(min)0 without BDF applied;
• (6) according to the fm* in Step (2) and the XBDF in Step (3), calculating the minimum value of generator negative electrical damping De(min)BDF with BDF applied;
• and
• (7) adjusting a value of damping resistor in BDF to make De(min)BDF in a range;
• wherein the range of De(min)BDF in Step (7) is chosen as
• De(min)0<De(min)BDF<De(min)0/2
• where De(min)0 is minimum value of generator negative electrical damping without BDF applied.