Balancing the power of transformers in low voltage distribution feeders by using the Back - to - Back power converter

This paper discusses a Back-to-Back (BTB) power converter based solution to avoid the overloaded operation of two low voltage feeders operating in parallel. With this purpose the BTB converter based on eight conditions of operation is proposed as means to exchange load between feeders to prevent overload conditions and balance the load on power transformers. The law of control of the BTB controller is designed in the dq frame of reference and linear theory is employed for tuning. The proposed BTB controller is implemented into test system composed by two 50kVA transformers supplying several loads. Through simulations, the capability of the BTB converter to share load between the interconnected systems is evaluated. Results indicate that the BTB converter is an autonomous and viable alternative to increase/decrease the loading of the lines and to improve the stability limits of the system. For the study, a 30kVA BTB converter is used.