Microgrid photovoltaic power generation

Add Time：2020/5/7    Views：249

1. System principle
Micro-Grid (Micro-Grid) is also translated as micro-grid, which refers to a small power generation and distribution system composed of distributed power, energy storage devices, energy conversion devices, loads, monitoring and protection devices. Microgrid is an autonomous system that can realize self-control, protection and management. It can operate on-grid with external power grid or in isolation. The purpose of the microgrid is to realize the flexible and efficient application of distributed power, and to solve the problem of large-scale and diverse forms of distributed power grid connection. The microgrid is a concept relative to the traditional large power grid. It refers to a network composed of multiple distributed power sources and their associated loads according to a certain topology, and is connected to the conventional power grid through static switches. The development and extension of the micro-grid can fully promote the large-scale connection of distributed power and renewable energy, and achieve a highly reliable supply of multiple energy sources in the form of load. It is an effective way to achieve an active distribution network and make the traditional power grid Smart grid transition.

2. Explanation of terms
DC microgrid: distributed power sources, energy storage devices, loads, etc. are all connected to the DC bus, and the DC network is then connected to the external AC power grid through power electronic inverter devices. The DC microgrid can provide electrical energy to AC and DC loads of different voltage levels through power electronic conversion devices. The fluctuations of distributed power sources and loads can be adjusted on the DC side by energy storage devices.

AC microgrid: Distributed power sources, energy storage devices, etc. are connected to the AC bus through power electronic devices. At present, AC microgrid is still the main form of microgrid. Through the control of the switch at the PCC, the grid-connected operation of the microgrid and the conversion of the island mode can be realized.

AC / DC hybrid microgrid: It contains both AC bus and DC bus, which can supply power directly to AC load and can supply power directly to DC load.

Medium voltage distribution branch microgrid: a microgrid that effectively integrates distributed power and load based on the medium voltage distribution branch, it is suitable for power supply to medium-capacity, high-reliability, and concentrated user areas .

Low-voltage microgrid: A microgrid formed by properly integrating users' distributed power sources and loads at a low-voltage voltage level. This type of microgrid is mostly owned by power or energy users and is relatively small in scale.