VEMoDrive drive systems

Frequency converter & Power converter

Frequency converters are essential devices in modern drive technology that adjust AC frequency and voltage to control the speed and power of electric motors. This technology enables precise control and optimization of processes in various industries, resulting in energy savings and improved performance.

Features

Frequency converters are characterized by their ability to vary the frequency and voltage of the current, allowing flexible control of motors. They typically consist of a rectifier, an intermediate circuit, and an inverter that work together to produce the desired output frequency and voltage. Key features include the ability to save energy, improved process control and protection features such as overload protection and short circuit protection. Modern frequency converters also offer extensive communication interfaces for integration into automation systems and are available in various power and voltage ranges.

Applications

Frequency converters and power converters are used in a variety of application areas. In industry, they are used to control pumps, fans and compressors to optimize energy consumption and extend the life of machines. In conveyor technology, they enable precise control of the conveying speed of conveyor belts and cranes. Frequency converters also ensure efficient heating, ventilation and air conditioning systems in building technology. They are also used in water treatment, where they adapt pump performance to demand, and in renewable energy, particularly wind power, where they optimize generator performance. On synchronous motors and generators, excitation devices ensure the necessary regulation of the field and thereby offer regulation of the reactive power or the power factor.

Our range of services

Under the VEMoDRIVE brand, VEM supplies controlled drive systems in the power range from 0.55 kW to 55 MW - in low and medium voltage.

As a leading manufacturer of electrical machines and a specialist in automation and drive technology, VEM has decades of experience in the planning, production, delivery, assembly and commissioning of controlled drive systems and their components. This guarantees high quality, reliability and customer satisfaction.

The proven motors from our production sites in Zwickau, Wernigerode and Dresden are combined with converters and automation technology from well-known manufacturers to create complete controlled drive systems with a focus on:

  • Variable Speed Drive System (VSDS) for energy and cost-optimized operation
  • Starting Converter systems for a smooth motor start even with heavy loads
  • Special applications such as high-speed drives, DC drives and subsynchronous converter cascades (SCC)

VEMoDRIVE thus offers a high degree of flexibility in solving automation and drive tasks for both new systems and modernizations. From engineering to after-sales service, all from a single source.

 

Low-voltage drive systems

With VEMoDRIVE low-voltage drive systems, we supply you with complete electrical drive equipment, combined from VEM motors, converters and transformers in the power range up to 4,000 kW in low-voltage design.

The VEM low-voltage converters impress with a consistent and user-friendly operating concept. They can be used to operate asynchronous, synchronous motors (separately excited, permanently excited) as well as synchronous reluctance motors. The converters are available in air- or water-cooled versions and, depending on the power, as wall-mounted (up to 200 kW) or cabinet units. Their modular design enables customer-specific solutions as a single-motor or multi-motor drive and ensures service-friendly handling.

Additional technical details

Output power
 0.55 kW to 4000 kW
Output frequency
 0 - 400 Hz
Operating mode
 2-quadrant operation with diode front end (DFE) and 4-quadrant operation with active front end (AFE, energy recovery)
Protection degree
 IP 21 or IP 54 (wall unit) and IP 23 or IP 54 (cabinet version)
 

Medium-voltage drive systems

With VEMoDRIVE medium-voltage drive systems, we supply you with complete electrical drive equipment, combined from VEM motors, converters and transformers in the power range up to 60 MW.

Through cooperation with well-known manufacturers, we can access a wide range of different converter types and topologies depending on the application, such as:

  • Multilevel converters with cascaded low-voltage cells for standard applications (pumps, fans, compressors, etc.)
  • Highly dynamic converters with high-voltage power semiconductors for special applications (rolling mills, conveyor belts, winches, etc.)
  • Thyristor-based converters as starting converters for large synchronous motors (LCI)

The close cooperation with our partners enables an optimal and therefore cost-effective design in terms of investment and operating costs.

Additional technical details

Output power
 200 kW to 60 MW
Output frequency
 0 - 120 Hz
Operating mode
 2-quadrant operation with diode front end (DFE) and 4-quadrant operation with active front end (AFE, energy recovery)
Protection degree
 IP 21 to IP 42
Harmonics
 in accordance withIEEE519

Subsynchronous converter cascades

With VEMoDRIVE SCC, VEM offers a subsynchronous converter cascade for your slip ring motor. The subsynchronous converter cascade is based on the series connection of an uncontrolled and a controlled converter in the rotor circuit of the three-phase asynchronous machine. It is used to return the slip energy to the supply grid and can set the speed of the motor in an energy-efficient manner using intelligent control.

VEMoDRIVE SCC can basically be used in all branches of industry, preferably where there are no requirements for high dynamics of the control and a limited speed adjustment range is sufficient. This applies, for example, to the drive of centrifugal compressors, fans and rotating pumps. The preferred power range of the motor is between 500 kW and 12 MW. By using a VEMoDRIVE SCC, a significant energy saving can be achieved compared to adjusting the quantity using throttles, e.g. in water pumps. The same applies to adjusting the speed using additional rotor resistors.

Existing drives with slip-ring motors can be upgraded to a controlled drive using VEMoDRIVE SCC, which is particularly advantageous. In addition to the SCC, VEM also supplies resistance starters, transformers and switching technology

VEMoDRIVE SCC kann grundsätzlich in allen Industriezweigen eingesetzt werden, bevorzugt dort, wo keine Anforderungen an eine hohe Dynamik der Regelung bestehen und ein begrenzter Stellbereich der Drehzahl ausreicht. Dies trifft z.B. für den Antrieb von Kreiselverdichtern, Gebläsen und rotierenden Pumpen zu. Der bevorzugte Leistungsbereich des Motors liegt zwischen 500 kW und 12 MW. Durch Einsatz einer VEMoDRIVE SCC lassen sich gegenüber einer Mengenverstellung über Drosseln, z.B. bei Wasserpumpen, eine erhebliche Energieeinsprung erzielen. Gleiches gilt im Vergleich zur Drehzahlstellung mit Hilfe von Läuferzusatzwiderständen.

Besonders vorteilhaft lassen sich vorhandene Antriebe mit Schleifringläufermotoren nachträglich mit VEMoDRIVE SCC zu einem geregelten Antrieb erweitern. Neben der USK liefert VEM auch Widerstandsanlasser, Transformatoren und Schalttechnik

Excitation systems for synchronous machines

Excitation systems provide the excitation current of synchronous machines and can regulate the stator voltage (generator) and the power factor or the reactive power of the machine or a complete electrical plant (phase shifter operation).

VEM supplies you with compact excitation controllers that are installed directly on the machine, right up to entire excitation units in cabinet design. These can also be equipped with components for motor control and monitoring as well as HMI systems for visualizing the machine and, if necessary, asset status. A wide range of standardized communication interfaces offers the possibility of communicating with other components of the drive system such as VFDs, soft starters or autotransformers as well as distributed control systems.

 

Softstarters

If speed or torque control is not required during start-up processes, but a limitation of the starting current, soft starters are used. They limit the starting current and thus the grid stress by starting the motors in a controlled manner up to the nominal speed. The integrated bypass then switches the motors to the grid and thus enables low-loss operation of the motors at a constant speed.

In addition to the standard bypass, VEMoDRIVE soft starters have other functions such as torque-controlled start and stop modes for soft starts at low current and pump stops without pressure surges. The dynamic vector brake process can be used to brake machines with a high moment of inertia in a controlled manner.

VEMoDRIVE soft starters also offer a variety of other useful features. These include monitoring functions for detecting load deviations and the possibility of remote control and diagnosis via communication interfaces. This enables easy integration into modern automation systems and improves ease of maintenance. The adaptability of the soft starters to different motors and load conditions makes them particularly versatile and reliable in operation. Another highlight is the ability to adjust acceleration and deceleration times to meet the requirements of specific applications. This minimizes mechanical stress on the system and extends the service life of the entire system.

 
 

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