Three-phase power grid phase-locked loop based on fractional order PID control and phase locking method thereof

• Main Authors: WANG XIAOHONG, ZHAI MINGYANG, LI YONGSHUN, PAN ZHIFENG, WANG YU, WU CHUNTAI, WANG ZIJIANG
• Format: Patent
• Language: Chinese; English
• Published: 23.11.2021
• Subjects: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATIONOF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES; BASIC ELECTRONIC CIRCUITRY; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

The invention provides a three-phase power grid phase-locked loop based on fractional order PID control and a phase locking method thereof, and the phase locking method comprises the steps: carrying out the calculation of three-phase power phase voltages ua, ub and uc and an electrical angle outputted by an electrical angle conversion module, and obtaining two-phase rotation voltages Ud and Uq; enabling the q-axis MAF module to update the notch frequency according to the output value of the arithmetic mean value filter module and the output value of the d-axis MAF module, and then filtering the input error U * q-Uq; updating the angular frequency variation output by the fractional order PID module according to the output value of the q-axis MAF; 4, enabling an electrical angle conversion module to convert the angular frequency variation output by the fractional order PID module into the electrical angle. The fractional order PID is adopted to compensate the phase lag introduced by the MAF, the open-loop cut-o