Exciter Step Test With Power System Stabilizer (PSS) T’do d-axis rotor open-circuit time constant – – OFF and unit offline, perform voltage reference step tests T’qo q-axis rotor open-circuit time constant – and monitor terminal voltage, field voltage and field Ka gain – current. With PSS OFF and unit online, perform step tests Lead/lag parameter verification at near full load and no load. With PSS ON and unit online, PSS functionality verification only require digital – perform terminal voltage step test. setpoints or a frequency test to verify PSS parameters. NOTE: PSS OFF tests verify models while PSS ON tests verify PSS models. Load Rejection Test1 With unit loaded , open the H Inertia constant – – breaker and observe the unit speed (frequency) with respect to time at an extremely high sample rate. Plot the tangential component of the frequency to get the initial acceleration to derive the inertia value. Nonlinear gain points power Power-Gate Test Accounting for the rated vs. actual – – Nonlinear gain points Gate head, the gate position is adjusted across its allowable – Droop (if not digital) range and active power is monitored. Qnl no-load flow at nominal head – Gmax/Gmin if sufficient operational capability – available. Blade-Gate Test The gate position is adjusted across its Nonlinear gain points Blade – – allowable range and blade position is monitored; this is a subtest of the power-gate test on Kaplan turbines Kp Governor Proportional Gain Speed Reference Test A % change in speed reference is – – Ki Governor Integral Gain applied and removed with the unit online above the – Kd Governor Derivative Gain rough zone with sufficient operating range to not reach – Ldref Load limiter the maximum gate or stator output limit and active – maximum gate opening velocity (may power, gate position, and blade position are monitored. – require larger step) Velcl maximum gate closing velocity (may require – larger negative step) Tp gate servo time constant – Tw verification of water time constant –
Exciter Step Test – With Power System Stabilizer (PSS) OFF and unit offline, perform voltage reference step tests and monitor terminal voltage, field voltage and field current. With PSS OFF and unit online, perform step tests at near full load and no load. With PSS ON and unit online, perform terminal voltage step test. NOTE: PSS OFF tests verify models while PSS ON tests verify PSS models. T’do – d-axis rotor open-circuit time constant T’qo – q-axis rotor open-circuit time constant Ka – gain Lead/lag parameter verification PSS functionality verification only – require digital setpoints or a frequency test to verify PSS parameters. Load Rejection Test1 – With unit loaded , open the breaker and observe the unit speed (frequency) with respect to time at an extremely high sample rate. Plot the tangential component of the frequency to get the initial acceleration to derive the inertia value. H – Inertia constant Power-Gate Test – Accounting for the rated vs. actual head, the gate position is adjusted across its allowable range and active power is monitored. Nonlinear gain points – power Nonlinear gain points – Gate Droop (if not digital) Qnl – no-load flow at nominal head Gmax/Gmin – if sufficient operational capability available. Blade-Gate Test – The gate position is adjusted across its allowable range and blade position is monitored; this is a subtest of the power-gate test on Kaplan turbines Nonlinear gain points – Blade Speed Reference Test – A % change in speed reference is applied and removed with the unit online above the rough zone with sufficient operating range to not reach the maximum gate or stator output limit and active power, gate position, and blade position are monitored. Kp – Governor Proportional Gain Ki – Governor Integral Gain Kd – Governor Derivative Gain Ldref – Load limiter – maximum gate opening velocity (may require larger step) Velcl – maximum gate closing velocity (may require larger negative step) Tp – gate servo time constant Tw – verification of water time constant
Reliability%20Guideline%20-%20Power%20Plant%20Model%20Verification%20using%20PMUs%20-%20Response%20to%20Comments%20-%202016-08-17.docx