Reaching the next level in industrial power supplies

Switched-mode power supplies have proven themselves in the industry thanks to their long service lives and robust design. Without a reliable power supply, modern plant engineering and process technology would be unimaginable. For particularly critical applications, being reliable isn’t enough. Within the chemical, pharmaceutical and process technology industry, system availability is critical. There must be no failures or the economic damage would be significant.

Assured reliability can be achieved using redundant power supply systems. Redundant systems feature two or more parallel connected power supplies: one power supply can fail without bringing power loss to the entire load.

Conventional power supply units must be connected in parallel using diode or redundancy modules for safe decoupling. Devices in the PROtop series can be connected in parallel directly. Innovative built-in ORing metal oxide semiconductor field effect transistor (MOSFET) technology reliably decouples the devices.

The biggest risk when connecting power supply units in parallel are electrolytic capacitors, which are typically used to smooth the output voltage. A capacitor can be a source of failure if its internal electrolyte dries out. A defective electrolytic capacitor can become a low-impedance path to the output, causing a short circuit and output voltage failure. When used correctly, with the high-quality components used in Weidmüller supplies, this problem rarely occurs. However, if the device heats up excessively, the expected life of the capacitors will decrease. This problem can be prevented by installing decoupling diodes, which not only provide protection in the event of a dangerous short circuit to ground, but also help protect against reverse current. In top-class power supplies, such as the PROtop series, Weidmüller uses integrated MOSFET components instead of external diodes.

MOSFET controllers monitor the voltage upstream and downstream from the ORing. In the event of reverse current, a voltage drop or internal short circuit, the internal rectifier is immediately disconnected from the load output. One of the major advantages of MOSFETs is their efficiency; the power losses are just 10% compared with typical diodes. This low power loss allows ORing MOSFETs to be directly installed into the power supply itself with no need for separate redundancy modules.

A DIP switch can be used to select the operating mode: single or parallel connection. In single mode, the device behaves like a conventional device with IU characteristic curve. In parallel mode, the voltage characteristic curve drops by 1 VDC from no-load idle up to the full-rated load. This soft IU effect provides good long-term stability as the voltage of two devices may vary by more than 50 mV over a period of 5–10 years and still load share accurately without the need for calibration. With conventional IU characteristic curves, one power source supplies the whole load; the other a minimal amount, causing one supply to wear more rapidly than the other. This effect is reduced by PROtop’s soft IU characteristic. In parallel mode, PROtop power supplies are as effective as costly external redundancy modules with active current sharing.

PROtop power supplies benefit from a compact design. This space-saving design allows for smaller cabinet sizes, reducing overall project costs. Thanks to PROtop’s high efficiency of up to 95.4%, heat loss is also significantly reduced, helping decrease internal enclosure temperatures and extend component reliability. The high mean time between failure (>1,000,000 hours by the IEC1709 [SN29500] standard), in addition to a long service life, guarantees a high level of return on investment over the entire installed lifespan.

PROtop supplies boast additional features such as dynamic current-limiting (DCL) technology. DCL can generate a short impulse overload of up to 600% of the nominal load, allowing PROtop to safely and reliably trip downstream miniature circuit breakers on the output DC circuit.

Weidmüller strives to rapidly integrate all devices and data to the cloud. The PROtop range is therefore prepared for networked connectivity, with an optional pluggable communication module. This allows for an existing site to have a future upgrade path towards Industry 4.0, with the utilisation of this data to support features such as condition monitoring and remote control.

With its impressive characteristics, PROtop is the first choice wherever reliability, long service life and energy efficiency are indispensable and redundant power supply systems are required, or for systems under harsh environmental conditions. Let’s connect.

Key features

• Weidmüller PROtop power supply with O-Ring MOSFET technology.
• Parallel operation without redundancy modules for maximum supply reliability.
• Sustainable space savings with easy installation and minimal power loss.
• Communicative and highly efficient power supply for the most demanding of applications.
   

Image courtesy of Weidmüller.