Nov 27, 2020

Complete Beckhoff system for power supply, overcurrent protection and energy monitoring

Transparent energy data solutions increase machine efficiency and open up optimization potential

Only universal and system-integrated current and energy handling results in maximum data transparency from power generation to energy monitoring. This in turn is the basis for increasing the efficiency of production machines and optimizing process sequences. PC-based control from Beckhoff makes this possible with matching components for power supply, fusing and monitoring.

Transparent energy monitoring reduces both machine downtime and the necessity to oversize the corresponding components for reasons of plant availability. Added to that are simplified preventive maintenance and ultimately considerably increased production efficiency. Hence, the wide range of PC-based control technology from Beckhoff offers a solution that can be optimally adapted to the respective application. This includes the numerous SCT current transformers and EtherCAT power measurement terminals for the integrated monitoring of the AC and DC supply, to the 24/48 V DC power supplies of the three new PS device series and the EL922x electronic overcurrent protection terminals.

Electronic overcurrent protection integrated directly into the EtherCAT I/O system is available in the EL922x EtherCAT Terminal series, which is only 12 mm wide.
Electronic overcurrent protection integrated directly into the EtherCAT I/O system is available in the EL922x EtherCAT Terminal series, which is only 12 mm wide.

Universal system reduces work and costs

No machine or plant works without reliable power supplies and the corresponding fusing. If this is additionally combined with high-performance recording of energy data, advantages already result during the design of the machine: additional power measurement technology at the power supply inputs provides an overview of the total power, including any losses. With the new, high-quality power supplies from the PS series, the system approach of PC-based control comes decisively to bear, because only when all components are optimally matched to one another can advantages be universally achieved. In particular, the EL922x overcurrent protection terminals integrated directly in the EtherCAT I/O system not only reliably secure the power in the individual supply paths, but also continuously measure it.

If machine manufacturers avoid power peaks with this holistic approach, for example, they reduce the connected load of the plant as well as installation costs for the end customer due to the smaller supply cable sizes. Furthermore, universal and system-integrated energy measuring technology satisfies the prerequisite for being able to compare the target and actual state of the plant directly inside the machine controller. In this way, developing damage can be detected at an early stage and process optimization potentials are easier to discover.

Until now, continuous data monitoring has mostly been associated with significant investments, often requiring costly integration of external sensors, sometimes with the help of specialized components. However, the power measurement terminals, current transformers, overcurrent protection terminals and power supplies from Beckhoff enable this with standard components and correspondingly low costs as well as reduced logistics requirements, e.g., for the storage of special parts – even when retrofitting existing machines and plants.

Data transparency through complete measurement chain

As an automation specialist, Beckhoff enables the combination of the relevant power supply components to form a transparent and complete system. Only such a combined implementation provides a comprehensive overview of the energy and power supply of the machine, on both the AC and DC sides. The complete measurement chain begins with the SCT current transformer at the main supply to the machine. The power supplies from the PS device series provide a safe 24 V DC for all connected automation components and the overcurrent protection terminals not only secure the individual lines behind them, but also continuously monitor the current consumption.

With the SCT series current transformers, Beckhoff has completed the power measuring chain from the recording of the physical measured values to the transmission of data to the cloud. The portfolio of current transformers covers all relevant applications: for current intensities from 1 to 5,000 A as well as ring-type and split-core transformer versions or 3-phase transformer sets. There is a choice of two concepts, which are highly scalable due to various designs and performance classes and are thus suitable for a wide variety of applications. The SCT series is extremely diversified, ranging from the low-cost 3-phase transformer sets – including for building services – and standard industrial transformers for controls engineering, through to solutions for test benches with particularly high accuracy requirements. Decisive for the selection of the suitable transformer variant is the respective field of use. Particularly in new systems, the data acquisition can be implemented cost-efficiently and with high measurement accuracy using the ring-type current transformers. Conversely, the split-core current transformers are ideal for use as an uncomplicated retrofit solution due to the simplicity of their attachment.

There is a wide variety of requirements in energy management in the machine environment and in the energy economy, ranging from pure grid monitoring and process control through to high-end power monitoring. Extended by four new EtherCAT I/Os, a comprehensive range of EtherCAT Terminals is highly scalable in terms of both price and performance. Together with the proven EL37x3 grid monitoring oversampling terminals (and the associated TF3650 TwinCAT Power Monitoring software library), the new EL34x3 EtherCAT Terminals for energy management make up a comprehensive range of products that optimally adapt to the respective application in a wide range of uses.

SCT current transformers suitable for 1 to 5,000 A are available as ring-type (both on the left) and split-core variants (both on the right).
SCT current transformers suitable for 1 to 5,000 A are available as ring-type (both on the left) and split-core variants (both on the right).

Distributed power measurement minimizes costs

The new concept of distributed power measurement offers a particularly efficient and inexpensive way to obtain exact power measurement data, even in high complex systems. The central element is the EL3446 6-channel current input terminal for measuring currents up to 1 A AC/DC. It can be used to determine precise power values, even with physically separated voltage and current measurement. Decisive here is that all relevant electrical data from the supply grid, including real measured values for power, can be determined with the EL3446 purely as a current measurement terminal. The voltage values required for the calculation of the power data are transmitted – precisely synchronized by the distributed clocks in EtherCAT – via an EL3443 three-phase power measurement terminal, which only needs to be installed once for each system. The active power and energy consumption for each of the up to six connectable phases are then calculated in the EL3446. The effective values of voltage and current as well as active, apparent and reactive power or frequency, phase shift angle and harmonics are thus available, enabling comprehensive grid analysis extending up to energy management.

This concept of distributed power measurement – with just one EL3443 and any number of EL3446s – minimizes hardware and installation costs. The wiring work for the voltage distribution is thus eliminated. In addition, the price per channel for power measurement is reduced by almost 50%, without having to reduce the sampling rate as the number of measuring points increases. Also, only the EL3443 power measurement terminal has to be secured on the voltage side by fuses. For all subsequent measurements, therefore, the fuses that are necessary with conventional power measurement are omitted.

Power supplies with optimized convection cooling

The new PS1000, PS2000, and PS3000 power supply series are the starting point for a powerful and safe power supply within the plant. They are suitable for virtually all areas of use – both in the 24 V and the 48 V DC range and extending up to motion control applications with high requirements for back EMF. Excellent convection, minimized power loss and high efficiency of up to 96.3% optimize the service life and reliability of the devices. The peak power capability of up to 150% makes it possible to provide up to 1.44 kW output power for short periods of time. Together with the space-saving design and high immunity to transients and overvoltages, this allows efficient and cost-effective application even in harsh industrial environments. In addition, the power supplies can switch off circuit breakers quickly and accurately through a precise tripping function, avoiding longer machine downtimes.

The devices are specifically designed with good convection cooling properties in mind. In addition, components that are particularly temperature-sensitive and prone to rapidly aging are placed at the bottom of the unit, i.e. as close as possible to the incoming cool air. Due to this universally temperature-optimized design, all components used are subject to less thermal stress and thus attain a long service life. In addition, components that are subject to less stress retain their technical characteristics for longer, and the influence of external heat is minimized. All this has a positive effect on reliability.

Analog monitoring terminal with fusing functionality

In the EL922x EtherCAT Terminal series, Beckhoff combines functions for comprehensive energy monitoring in a highly compact way with electronic overcurrent protection for fusing 24 V DC plant components. Thus, these analog monitoring terminals record the current and voltage values for continuous power monitoring. Among other things, these data enable a detailed analysis of power consumption and voltage as well as the monitoring of voltage limit values. Furthermore, status information (on, off, triggered), trigger events (overload, short circuit) and preliminary warnings can be displayed.

The integration of electronic overcurrent protection directly into the EtherCAT I/O system reduces the costs and space required in control cabinets compared to other fusing products, without the need to use a conventional electronic solution as an inflexible stand-alone system. EL9227 EtherCAT Terminals also meet the most diverse requirements through numerous settings and process data options that enable transparent system monitoring. A total of 19 different 1 and 2-channel overcurrent protection terminals are available for current loads up to a maximum of 10 A.

The system-integrated overcurrent protection offers numerous practical advantages. This reduces wiring work, as the supply to the neighboring I/O terminals connects automatically when the terminal is plugged in. In addition, the control cabinet design benefits from space and cost savings by eliminating an otherwise necessary additional coupling device and further digital I/O or supply products. Furthermore, EtherCAT offers access to numerous process data such as load, load current, input/output voltage, under/ overvoltage and reverse supply.

Hans Beckhoff, managing director and owner of Beckhoff Automation.
Hans Beckhoff, managing director and owner of Beckhoff Automation.

Power supplies as system components

“Every automation solution requires a power supply,” says Hans Beckhoff. “In the past we did not have them in our portfolio, but we have changed that now.” Having a reliable supply of 24 V or 48 V power for automation products is a prerequisite for a trouble-free and long-lasting operation. Beckhoff has plenty of experience in interacting with power supplies for compact drive technologies and the XTS system, for example.

Having a solid interaction with the power supply is also critical for the operational reliability of IPCs and electronic overcurrent protection devices in terminal format (EL922x). “We are now making the extensive experience we have already gained available in the form of a broad portfolio of one- and three-phase power supplies with our PS1000, PS2000 and PS3000 series,” says Beckhoff. The power supplies are optimally matched to the company’s automation components and are highly efficient. “As a system provider, we will now be able to provide our customers with comprehensive advice and appropriate solutions also in the field of power supplies,” emphasizes the graduate physicist.