The voltage is increasing, but the network remains stableMaintenance-free linear regulator from EBG
Energy production is changing from centralised generating plants to decentralised units – this is mainly due to renewable energy sources such as biomass and photovoltaic systems. This being the case, it is possible that the power flow direction can change if there is an insufficient amount of users or loads. This could also lead to an impairment of the higher-level networks.
Due to their variety, PV systems from private households which feed into the low-voltage network can lead to voltage increases in the network and thereby shut down whole areas if the system voltage rises beyond the tolerated range of ±10%. Since the input of renewable energy may not be limited, this forces network operators to take action. However, network expansion should be avoided due to the large investments involved.
A much more economical solution is available in the form of a control system which is being offered by the Lünen-based Elektro-Bauelemente GmbH and Magtech AS, a Norwegian company. EnBW Regional AG has been intensively testing the control system in the local network of Wolpertswende since October 2012.
The highly efficient installation of additional PV systems is easily possible
The so-called “linear regulator” system is based on the intelligent and continuous control of an impedance which, together with additional coils, makes it possible to continuously keep the system voltage within permissible limits. Sudden changes to the feed-in process are constantly controlled. If there is a complete absence of the photovoltaic supply, the voltage regulator is automatically bypassed by means of a bypass circuit.
The lifespan of a magnetic voltage regulator is similar to that of distribution transformers in the network. Depending on the version, it is maintenance-free. High over-voltage and over-current strength as well as short-circuit strength guarantee a safe and long-term functionality. It is self-regulating and does not require expensive, failure-prone electronics. The linear regulator does not have moving mechanical parts, and connections to remote monitoring stations are not necessary; neither are adjustments required. It is perfect for sparsely populated regions where the feeder and consumers are not able to be quickly reached and are therefore more reliant on an electricity network which will work smoothly all the time.