This diploma thesis presents the process of connecting a biomass cogeneration plant to a low voltage electricity network. The procedure is presented through the electrical analysis contained in the Study of the optimal technical connection solution and connection conditions specified in the Electricity Approval. The connection is made via a block transformer (10 / 0.4 kV) within the plant itself, to the lower voltage side of which the generator (0.4 kV) is connected, while the higher voltage level is connected to the medium voltage of the network (10 kV). Furthermore, the procedure of conducting all necessary calculations is presented, both the existing condition of the network and after the connection of the cogeneration plant, all in the form of creating technical conditions in the network. The calculations primarily referred to the calculation of power flows, the amount of short-circuit current, and the relative voltage changes in the network nodes. All calculations were performed in the NEPLAN software package. After connection of the cogeneration plant to the network, there is a voltage change that exceeds the permissible values (90-110% of the rated voltage). The paper explains the ways to reduce the voltage change through the process of reducing the power factor of the power plant production and replacing the existing lines. When connecting a power of 500 kW, the voltage change is reduced to the permissible values by changing the production power factor in such a way that the plant operates in the mode of maintaining the voltage with reactive power. When connecting another 500 kW power plant, the connection power to the grid was 2 x 500 kW, and in that case, in addition to reducing the power factor of the power plant production, the existing lines were changed into cables with a larger cross section, since a larger cross section represents lower resistance, and thus a smaller voltage change. In conclusion, one cogeneration plant with a connection power of 500 kW with a load power factor cosꝬ = 0.95 can be connected to the existing network without the necessary works on the network.