Integration of Solar PV with Low-Voltage Weak Grid System: using Maximize-M Kalman Filter and Self-tuned P&O Algorithm

摘要： This paper introduces a novel 'self-tuned perturb and observe (P&O)' (SPO) algorithm for quick maximum power point tracking (MPPT) and a novel maximize-M Kalman filter (MMKF) based control technique for optimal operation of 'grid-integrated solar PV system, where linear/nonlinear loads are attached at PCC (Point of Common Coupling)'. Proposed SPO is the improved form of perturb and observe (P&O) algorithm, where inherent problems of traditional P&O like steady-state oscillation, slow dynamic responses and fixed step size issues, are successfully mitigated. Therefore, SPO tracks maximum power peak (MPP) very rapidly and it very accurately extracts maximum power from the PV array. The extracted power is used to meet the active power requirement of loads, and after meeting the load demand, the excess power is supplied to the grid. During power feeding, the power quality and power management are maintained by the MMKF based control technique. In control strategy, the MMKF is used for fundamental harmonic component extraction from the grid voltage and load current, even when the grid voltage is characterized by adverse situations, like sag, swell, harmonic distortion, DC offset etc. Here, the SPO MPPT algorithm and MMKF based control techniques, are tested on a developed prototype. The efficient and reliable performances of SPO MPPT algorithm and MMKF based control algorithm, in dynamic as well as in steady-state condition, are demonstrated under insolation variation conditions, nonlinear loading, as well as in different grid disturbances such as over-voltage, under-voltage, phase imbalance, harmonics distortion in the grid voltage etc.