生物质垃圾是人们在生活中所产生的废物，包括固体或液体等多种形态。厌氧发酵产沼气是一种有效的生物质垃圾处理方式，沼气的有效利用，可以有效降低沼气工程运行费用；沼气发电并网可生成有效能源，还可改善排气质量，节能环保。

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.

沼气发电机组并网中的发电机与电力系统采用并联方式运行。运转台数由PLC根据沼气池储气燃料的多少、工艺管路的回水温度高低、发电机运转状态以及运转的先后次序来指定启动哪一台发电机和具体台数，因此每天都需要使某些发电机投入或退出系统，进行并列和解列操作。发电机的非同期并列，会产生很大的冲击电流，不但会危及机组自身的安全运行，还会使电网产生波动、破坏稳定性。因此，必须要要求同期装置和控制、保护装置齐全可靠。、

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.

发电机并网发电，必须满足以下条件：

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

1）发电机组与电网的频率相同；

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

2）发电机组与电网的电压相同，其误差应在5%以内；

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

3）发电机组与电网相位一致；

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

4）发电机组相序与电网相许一致。

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