DP Single-Phase Photovoltaic Grid-Connected System

The single-phase photovoltaic grid-connected system serves as a typical solution for converting solar energy into AC power and integrating it into the grid. The core of this system lies in the inverter control strategy, where the mentioned DP (potentially referring to dual-loop control or a specific algorithm abbreviation) combined with PI control is crucial for achieving stable grid integration.

When modeling in SIMULINK, the system generally includes the following key modules: 1. Photovoltaic array model simulating the output characteristics of solar panels 2. Maximum Power Point Tracking (MPPT) algorithm ensuring energy conversion efficiency (commonly implemented using Perturb and Observe or Incremental Conductance methods) 3. DC-AC inverter employing dual-loop control structure (outer voltage loop + inner current loop) 4. Phase-Locked Loop (PLL) for grid synchronization 5. Filter circuit eliminating high-frequency harmonics

PI control in the system primarily implements: - Outer voltage loop maintaining DC-side voltage stability - Inner current loop ensuring grid-connected current quality This control structure can be implemented across SIMULINK versions 2012-2018, though attention should be paid to subtle differences in power electronics module libraries between versions. During system simulation, particular attention must be given to grid standards regarding THD (Total Harmonic Distortion) and power factor requirements. The implementation typically involves tuning PI parameters using Ziegler-Nichols or automated optimization methods for optimal dynamic response.