生物質垃圾是人們在生活中所產生的廢物，包括固體或液體等多種形態。厭氧發酵產沼氣是一種有效的生物質垃圾處理方式，沼氣的有效利用，可以有效降低沼氣工程運行費用；沼氣發電并網可生成有效能源，還可改善排氣質量，節能環保。

Biomass waste is the waste generated by people in their daily lives, including various forms such as solid or liquid. Anaerobic fermentation to produce biogas is an effective way of treating biomass waste. The effective utilization of biogas can effectively reduce the operating costs of biogas engineering; The grid connection of biogas power generation can generate effective energy, improve exhaust quality, and save energy and environmental protection.

沼氣發電機組并網中的發電機與電力系統采用并聯方式運行。運轉臺數由PLC根據沼氣池儲氣燃料的多少、工藝管路的回水溫度高低、發電機運轉狀態以及運轉的先后次序來指定啟動哪一臺發電機和具體臺數，因此每天都需要使某些發電機投入或退出系統，進行并列和解列操作。發電機的非同期并列，會產生很大的沖擊電流，不但會危及機組自身的安全運行，還會使電網產生波動、破壞穩定性。因此，必須要要求同期裝置和控制、保護裝置齊全可靠。、

The generator in the grid connected biogas generator set operates in parallel with the power system. The number of operating units is specified by the PLC based on the amount of gas and fuel stored in the biogas tank, the temperature of the return water in the process pipeline, the operating status of the generator, and the order of operation to start which generator and the specific number of units. Therefore, it is necessary to put certain generators into or out of the system every day for parallel and parallel operations. The asynchronous parallel operation of generators can generate significant surge currents, which not only endanger the safe operation of the unit itself, but also cause fluctuations and instability in the power grid. Therefore, it is necessary to require complete and reliable synchronization devices, control and protection devices.

發電機并網發電，必須滿足以下條件：

The generator connected to the grid for power generation must meet the following conditions:

1）發電機組與電網的頻率相同；

1) The frequency of the generator set is the same as that of the power grid;

2）發電機組與電網的電壓相同，其誤差應在5%以內；

2) The voltage of the generator set and the power grid should be the same, and the error should be within 5%;

3）發電機組與電網相位一致；

3) The generator set is in phase with the power grid;

4）發電機組相序與電網相許一致。

4) The phase sequence of the generator set is consistent with that of the power grid.