Commissioning of LVRSys^®
at a Siemens Data Centre
(RES-Project)

Project Scope

We recently implemented the LVRSys^® system at a Siemens Data Centre in Johannesburg, ensuring reliable power quality for critical infrastructure. This project included the installation and commissioning of our advanced voltage regulation technology, designed to meet the high demands of modern data centre operations.

Project Highlights
• Enhanced Voltage Stability: Ensured uninterrupted functionality of the data centre.
• Improved Energy Efficiency: Achieved significant reductions in operational costs.
• Seamless Integration: Successfully integrated with the existing power infrastructure.

This successful implementation highlights our expertise in delivering robust and reliable power solutions for high-stakes environments.

In the following lines some technical details are summarized:

The principle of LVRSys^® control is similar to a linear regulator. By coupling and uncoupling two transformers with selected transfer ratios, it is possible to regulate the output voltage in 9 steps. The thyristors switch intelligently and avoid any current surges, voltage dips and harmonics.

Example of 3 % voltage reduction

Generation of the voltage levels in 9 steps, e.g. 6% system

Regulation parameters are:
• Set point (voltage value, 3-phase)
• Tolerance band +/- (Upper/Lower limit value of the tolerance area)
• Reaction time
• Balancing of the 3-phase voltages within the tolerance area

Regulation Range

Balancing of the three-phase voltage

The phase-independent regulation enables the balancing of the three-phase voltages and thus improves the power quality of the grid. Three-phase loads, such as motors, operate with a symmetrical voltage more efficiently and have in consequence a longer product life cycle.

Robust

• Twenty billions of switches
• Short circuit proofed up to 50 kA
• High resistance to over voltages, direct and indirect lightning strikes
• Overloading (as NH-Fuse)

Grid compatibility

• No grid interference, causes no flicker or harmonics
• Balancing of the voltage via phase-independent regulation
• Existing fuse concept can be maintained
• Interruption-free power supply guaranteed ( Automatic Bypass )

Intuitive and secure

• Installation as a cable distribution cabinet
• Common connection via NH-switch disconnectors
• Commissioning via NH-switch disconnectors or Circuit breakers
• Fully encapsulated system for maximum touch protection

Reliable and economical

• High efficiency
• Passive cooling even in direct sunlight
• Operation temperature -40 °C up to +50 °C ambient temperature
• Electronics moisture-proof housed in the internal control cabinet (IP66)

Flexible and fast

• Adjustable response time of the controller < 30 ms up to 100 s
• Adaption of the control algorithms to different applications
• Line drop compensation, without additional communication
• Independent tolerance bands

Easy

• Data export via USB-Stick into e. g. MS Excel
• Firmware update via USB-Stick or SCADA Systems
• Common communication interfaces Modbus TCP, IEC 60870-5-104
• Drag indicator in the Display

Voltage Stabilisation of Vital Infrastructure

Standards EN 50160 and NRS048 define, among other criteria, the voltage range within which the mains voltage must remain. The permissible tolerance limits are ±10% based on the nominal voltage U N (400 V line-to-line), resulting in an allowable voltage band of ±40 V around U N .

Machines, drives, and lighting equipment operate most efficiently when the applied voltage is at the optimal operating point, which is generally the nominal voltage of the network. When the voltage deviates from this point, both the efficiency and the service life of drive equipment decrease. In particular, lighting devices such as LEDs experience a significant reduction in lifespan as the voltage increases.

For industrial applications, voltage controllers can be configured with response times of less than 30 milliseconds to address these issues. In industrial settings, systems and machines are typically powered by a three-phase connection. These systems operate most efficiently at the nominal voltage U N (e.g., 230 V line-to-neutral), leading to potential energy savings.

Three-phase motors, in particular, are adversely affected by unbalanced phase voltages. The asymmetry between phases L1, L2, and L3 is significantly reduced by voltage control, resulting in enhanced efficiency and extended service life (e.g., longer alternating cycles for motor brushes).