The solar inverter is the “heart” of the photovoltaic power generation system. Its core is to convert the direct current (DC) generated by photovoltaic panels into usable alternating current (AC), and achieve efficient power generation, safe grid connection and intelligent management.

I. Basic Introduction

The Photovoltaic Inverter is the core equipment of the photovoltaic system, responsible for converting the unstable direct current generated by the photovoltaic modules into stable alternating current that meets the grid standards or load requirements. Without it, the electricity generated by photovoltaic power cannot be directly used by household appliances and factories, nor can it be connected to the power grid for sale.

Ii. Core Functions

Electrical energy conversion (DC→AC)

Dc boost: Boost the low-voltage DC power output by photovoltaic panels (such as 12-600V) to the high voltage required for inversion (600-1500V), reducing transmission losses.

Inverter conversion: By rapidly switching power devices such as IGBT/MOSFET, direct current is converted into PWM alternating current pulses.

Filtering and shaping: After LC filtering, a pure sine wave (THD<3%) is output, matching the voltage, frequency (50Hz in China) and phase of the power grid/load.

2. Maximum Power Point Tracking (MPPT

Real-time tracking and locking of the optimal operating point of photovoltaic panels can maximize power generation when there are changes in light, temperature and shadow, usually increasing efficiency by 10% to 30%.

3. Grid connection control and grid support

Phase-locked synchronization (PLL) : Ensures that the output AC power is exactly the same as the grid voltage, frequency and phase, achieving seamless grid connection.

Island protection: Immediately shut down the power grid when there is a power outage to prevent power supply to the faulty grid and ensure the safety of maintenance.

Low-voltage ride-through (LVRT) : The system remains stable without disconnection during short-term voltage drops in the grid.

Power regulation: Active and reactive power output can be adjusted according to dispatching requirements to support the stability of the power grid.

4. System protection

Input: Overvoltage, undervoltage, reverse connection, overcurrent protection.

Output: Short circuit, overload, over-temperature and lightning protection.

Equipment: Protection against IGBT overcurrent, busbar overvoltage, fan failure, etc.

5. Operation Management and Monitoring

Automatic start and stop: Start at sunrise, stand by at sunset, and operate adaptively on rainy days.

Data acquisition: Real-time monitoring of voltage, current, power, power generation, efficiency and temperature.

Communication and Remote: Supports WiFi/4G/RS485, can be connected to the cloud platform to achieve remote monitoring, fault diagnosis and parameter setting.

6. Mode adaptation

Grid connection mode: Self-generated and self-consumed, surplus power fed to the grid, mainstream household/industrial and commercial/power station solutions.

Off-grid mode: Equipped with a battery, it independently supplies power to areas without power grids (mountainous regions, islands) or emergency scenarios.

Hybrid/energy storage mode: Seamless switching between grid-connected and off-grid, supporting photovoltaic and energy storage, achieving peak shaving and valley filling as well as backup power supply.