Avoiding grid expansion costs from renewables

Paul Boughton

AEG Power Solutions has developed a voltage regulator for low voltage 400V electricity supply grids that solves problems created by fluctuating renewable power feed-in of voltages going out of acceptable tolerance band, writes Nick Flaherty.

As the number of renewable installations such as photovoltaics (PV), combined heat and power (CHP) and smaller wind turbines grows, so too do the requirements for local grid operators and existing network infrastructure.

Solar panels on a consumer’s house can become a source of electrical energy, which means that power flow is reversed and voltage drops on impedance reverse as well. On a sunny day, this may cause grid voltage levels to exceed the upper tolerance of +10% because of high solar (PV) feed-in with low consumption at the same time.

Previously, grid operators have needed to invest in costly grid expansion and lay new cables to overcome this problem. Instead, Thyrobox VR can operate as a voltage regulator in low-voltage networks. Once the power flow reverses, the voltage connected to the secondary network segment is adjusted downwards by up to 8%.

Control is continuous and infinitely variable without switching operations, and efficiency is greater than 99.5%. This means that the entire voltage range can be better utilised, and in many cases, no new underground cables have to be laid – saving substantial upgrade costs for operators, which can then be passed on to consumers as lower bills.

“With solar power and other renewables becoming increasingly common, grid operators face a challenge to regulate voltages,” said Dr Stefan Kempen, Product Manager AdvancedPower Systems at AEG Power Solutions. “Thyrobox VR provides an innovative solution that is built around reliable, proven technology, and meets all relevant industry standards.”

Thyrobox VR is based on robust thyristors, and provides stepless, continuous control of line voltage with a state-of-the art controller hardware platform. This means it avoids sudden voltage changes, which can lead to flickering lights and damage to consumer equipment.