The manufacturing world is changing, with more plants incorporating automated machines and systems that promote flexibility and energy efficiency. Power and energy management systems are a critical part of this equation — especially as companies look to prioritize sustainability, optimize their energy usage and monitor consumption patterns. In particular, automated factories can benefit from power and energy systems that can:
- Stabilize the grid.
- Manage and reduce peak loads.
- Store excess energy generated during low-demand periods.
- Monitor energy consumption, increasing process transparency.
- Come to a safe, controlled stop after a power outage.
- Reduce the gauge size of cabling.
As it stands, there is an opportunity to achieve these objectives using a modular and intelligent approach to managing power and energy for industrial drives. The enabling technologies behind this approach include a combination of inverters, capacitors, regenerative energy modules and a DC link coupling that optimizes the drive system’s energy, reduces peak loads and lowers installation, operating and infrastructure costs.
An alternative to conventional drive technology with brake resistors, which convert all electrical energy into unusable heat, this power and energy management solution uses and stores energy, making it available to the drive system during normal operation without burdening the supply grid, as well as during power failures.
By deploying such a system — configurable according to your unique application — you can take the necessary steps to improve how energy is used in your automated production process. At the same time, this solution offers complete transparency into energy usage via monitoring capabilities. The result: greater system availability, flexibility and scalability at a lower cost, allowing you to keep pace with the evolving manufacturing landscape.
An Overview of the Technology
Part of the MOVI-C modular automation system, this power and energy management system is suitable for machines that involve dynamic accelerations and decelerations, which waste energy during braking and spike energy during startup. Control cabinet inverters compensate for peaks by temporarily storing the braking energy generated by the machine or system, then making the energy available as needed. In terms of its effect on the energy grid, this technology stabilizes the energy flow and reduces spikes. It also reduces complexity at the level of the machine. For example, designers no longer have to design their machines and systems around power peaks. Instead, they can design their systems according to average power using smaller, lighter-weight connections, wire sizes and control cabinet components.
Other advantages of this inverter technology include the following:
Reduced power peaks. The storage capacitors in the DC link provide most of the required peak power, reducing energy, connection and control cabinet costs. For example, instead of requiring a supply system cable with a size of 75 mm2, a 75-kilowatt (kW) system will now need a 6-mm2 cable.
Uninterrupted system operation. Rotational energy, combined with the energy in the storage capacitors, serve as an uninterruptible power supply. This energy is used to power the drives, motor brakes and 24-volt (V) level PLC.
Reduced harmonic load in the grid. This inverter system achieves a power factor of 0.95. From as low as 20 percent of the nominal power, the power factor is 0.09. Even under difficult connection conditions, this system does not put the grid under further strain.
Ease of maintenance. By using capacitor storage units instead of chemical batteries, this power and energy management system can be completely discharged to 0 V for setup, service, maintenance and transport tasks.
Online monitoring. Users can configure energy meters, which are triggered by external events. Measurement technology integrated into the hardware also provides full transparency of power, performance and energy consumption.
Greater availability. This comprehensive power and energy management solution increases system and machine availability and — under certain operating states — makes operation possible in the first place.
Greater scalability. Thanks to its use of various capacitor storage units, this technology scales over a wide energy range: 2 to 10,000 kW. Because the devices are modular in nature, there are few limits to its possible applications.
Connection to external DC supply systems. The DC link connects bidirectionally to external DC supply systems using a DC-DC converter.
Measurement data for ISO 50001 systems. Users can integrate the power supply modules, which measure performance data and provide energy meter readings, into ISO 50001 energy management systems.
Easy connectivity. This technology can connect to higher-level controllers via PROFINET, EtherNet/IP and Modbus/TCP. In addition, selection, installation, startup and operation are quick and easy, thanks to engineering tools and prefabricated MOVIKIT software modules.
Application Examples
We can demonstrate the many benefits of this power and energy management system using an application example that involves lifting and lowering goods at an automated lifting station. This system incorporates MOVIDRIVE Power and Energy Solution products, which are set to run in Power Mode (see sidebar for more information about supported topologies). This solution reduced the peak power output during the upward acceleration by a factor of 15. It also reduced energy costs to 60 percent compared to a previous setup that included braking resistors.
In addition, in the event of a power failure, the MOVIDRIVE system will complete the downward movement by using the energy stored in the capacitor. It will also bring the upward movement to a halt in a controlled manner — at which point it also applies the brake. Power and energy modules provide the ISO 50001 energy management system with measured values, enabling operators to visualize the system’s energy consumption and identify deviations that may indicate component wear or stiffness.
A second application involved a cold storage facility that included many machines and systems, such as stacker cranes with shuttles, pallet transfer shuttles and rail-guided vehicles for hoists and conveyors. Some of the technical requirements for this project included: a high grid quality — and therefore no use of regenerative power supplies; no braking resistors, as their thermal output would need to be offset in the cold storage facility; a high degree of capacity utilization; and rapid return on investment. The use of energy storage capacitors and products from the MOVI-C modular system unlocked the following benefits:
- Rapid return on investment by downsizing the electrical installation.
- Reduced peak power from 140 to 25 kW per storage and retrieval system.
- High grid quality and greater energy efficiency thanks to internal energy recovery.
- Greater operating time — the diversity factor of the stacker cranes increased to 100 percent.
Sew-Eurodrive
Moving Toward the Modular Factory
Modern factories must be more flexible than ever — especially as manufacturers face mounting pressures to expand digitalization, increase throughput, support sustainability and meet ever-changing customer requirements. Power and energy management technologies must take these various developments into account in a way that optimizes the energy consumption of automated systems, unlocking new productivity, sustainability and economic benefits.
Learn more at seweurodrive.com.