Uniform direct current - Wöhrle Market Insights

Although the DC busbar was an important component of the overall system in mechanical engineering in the past, it was subordinate to the AC power supply. However, more and more machine components are dependent on a regulated and fail-safe DC supply. Programmable logic controllers (PLCs) are often supplied with direct current, as are a large number of actuators and sensors for control and monitoring. A failure of the DC power supply would have fatal consequences for operation.

Even less drastic faults, such as deviations from the nominal voltage, can no longer be tolerated today, as actuators and sensors react sensitively to irregularities in the supply voltage or even change their function.

For example, unregulated DC motors run faster or slower when the supply voltage changes.

In addition, not all sensors have stabilized constant voltage sources as a reference.

DC UPS for sensitive loads

Next-generation DC UPSs, such as the UGVNG 20 from Wöhrle, solve this problem with a cleverly selected microprocessor controller and also offer a wealth of other functions. They naturally ensure a stable output voltage, regardless of the input. The DC-DC converter used for this purpose also allows a wide voltage range between 12 and 48 volts, which means that the UGVNG 20 can be used in practically any scenario.

More importantly, the microprocessor control makes the UPS highly flexible when it comes to selecting the energy storage system. All options are possible, from conventional lead cells to nickel-metal hybrid and lithium-ion batteries through to supercaps. Developers can select the perfect storage system for every application, for example supercaps when very high discharge currents and temperature insensitivity are required. Pre-assigned charging characteristics quickly adapt the UPS to the selected storage system, while users can set detailed parameters themselves.
To maximize the service life of the storage tanks, the device offers an interface for an NTC temperature sensor, which monitors the battery temperature and automatically adjusts the charging parameters accordingly.
Maintenance intervals can thus be extended and service costs saved.

Flexibility thanks to large parameter set

The programmability of the UPS is an extremely important distinguishing feature. In addition to the aforementioned output voltage, which can be set from 12 - 48 V in 0.1 V increments, current limits and other limit values can be programmed. If these limit values are reached, this can be shown flexibly on the display or signaled via two programmable relays. In addition to signaling, log entries are created and flags are set so that status or error analyses can be carried out later.

A USB connection and free software for Windows are available for convenient access to this data and the more than 200 variables and parameters. However, control via Modbus RTU is also possible. This allows the statuses and data to be queried at runtime and the corresponding actions to be carried out.

As management tools via TCP/IP are increasingly being used in industry, Wöhrle also offers an SNMP adapter based on Modbus. This allows the device to be controlled entirely via SNMP, an important advantage in application scenarios at remote locations where the central control station has to deal with as few protocols and technologies as possible.

Useful details for practical use

Details such as the simple mass configuration of identical systems using a template often determine the practical and series suitability of a solution. Wöhrle can carry out and provide the initial processing of a parameter set for the customer. On request, the template developed can be rolled out to all systems ex works and the devices delivered ready for immediate use.

The UGVNG 20 from Wöhrle as the optimum solution for your application

Many sensitive DC consumers that cannot tolerate voltage fluctuations or even power failures are used in mechanical engineering today. Uninterruptible power supplies such as the UGVNG 20 from Wöhrle power supply systems protect PLCs, sensors and actuators from voltage failures and other impairments to the DC power supply. Numerous programmable parameters, several energy storage options and comprehensive communication channels make the UGVNG 20 a flexible protection element. System architects and developers can rely on the comprehensive know-how and support of Wöhrle Stromversorgungssysteme GmbH to obtain a solution optimized for their application.