powerbox VR Voltage Regulation of distribution grids

With the growing number of solar installations, requirements increase for local distribution system operators and their existing network infrastructures. In the past electrical distribution systems have been designed for a power fl ow from high voltage via medium voltage to low voltage with the consumer or end user being a sink of electrical energy. Now, the user can become a source of electrical energy. In this case the power flow is reversed and voltage drops on impedance reverse as well. This can result in exceeding the upper voltage tolerance (+10%) especially in network spur lines. Without any changes at the existing network infrastructure this would cause automatic switch-off of solar inverters with the consequences of dissatisfi ed customers and additionally failure to meet legal objectives as preferred by renewable energies.

VOLTAGE REGULATION OF DISTRIBUTION GRIDS

These requirements confront local distribution grid operators, especially in the countryside, ie where farms or sports clubs are connected via spur lines. Up until now the only solution has been to install new cables in expensive and time consuming installations. This causes undesirable delay and additional cost for the operator. With powerbox VR, ALFA Power Solutions offers a new concept.

powerbox VR

powerbox VR operates as a voltage regulator within low voltage networks. Once the power fl ow reverses, the voltage of the secondary connected network segment will be adjusted downwards by up to 8%. Regulation is continuously stepless with no switching operations and a degree of effi ciency >99% according to power rating. Therefore the voltage range is signifi cantly easier to utilize and the installation of cables can be avoided in many cases.

The basic technology has been known of since the late 1920’s and has been upgraded in the 1970’s using SCR semiconductor devices with step control. ALFA UPS has further developed the technology for continuous regulation and brought it to a state of the art hardware platform using best in class thyristors and controllers. The Thyro-P control unit has been proven over many years in demanding applications and also provides necessary interfaces to various communication tools.

The dimensional construction of powerbox VR is similar to common cable distribution cabinets. The installation is similar to cable distribution cabinets i.e. on a concrete base, through which the cables will pass and therefore an installation is possible along sidewalks, cycle ways and side roads.