The IndraDrive ML extends the IndraDrive series into the upper power range: individually up to 500 kW, connected in parallel up to 8 devices and up to 4 MW. These space-saving, modular inverters are real all-rounders – they can be used as a mains power inverter or as a motor inverter. This minimizes the variants, simplifies handling and reduces your storage costs. And you save energy at the same time.
As the newest member of the IndraDrive family by Rexroth, IndraDrive ML offers flexible solutions with intelligent functions for powerful drives – all the way up to the megawatt-area. With these Large Electric Drives, Rexroth is helping machine manufacturers overcome the rising pressure of today's markets to reduce costs while increasing productivity, flexibility and efficiency.
IndraDrive ML offers numerous benefits for our customers
Through power regeneration, DC coupling for multi-axis systems, concepts for static and rotating energy storage as well as Smart Energy Mode, diverse possibilities for energy savings are available. Alternative cooling types also offer different possibilities for the removal and use of waste heat.
Powerful, flexible, intelligent
The modular universal power inverters are predestined for all types of multi-axis applications as they are powerful and versatile drives that can be used in the megawatt range. Universally deployable for standard and servo implementations, with comprehensive additional options to align on-demand output with a wide variety of applications. The inverters also incorporate all the aspects that the IndraDrive family is known for, from certified safety technology, to drive-integrated motion logic solutions, through to multi-encoder interfaces and multi-Ethernet communication. A truly universal development!
Here is an overview of industries in which the IndraDrive ML makes new possibilities for innovative machine concepts available.
Optimal device topology – for a broad area of applications
The universal power inverters in the IndraDrive ML modular system can be used as motor inverters to operate synchronous and asynchronous motors or as mains inverters with energy-recovery capacity. This not only reduces inventory, but also system complexity. The drive series offers a good balance of incremental power outputs. The wide voltage range facilitates applications in many different industries and regions.
Universal power inverter as a shared power output basis
Large electric drives from Rexroth can either be used as motor inverters or mains inverters with regenerative power capacity (supply unit); the control unit is what defines the operative function. This reduces variant diversity and storage costs.
Power electronics for ultra-high demands
Configured as a mains inverter with regenerative power capacity, the active inverter keeps mains feedback to a minimum while the regulated DC bus voltage ensures independence from the supply voltage across a wide range of 380 V to 500 V as well as a high level of tolerance for balancing out fluctuations in voltage. Cycling with high PWM ensures that the motors are optimally used, and noise emissions are kept as low as possible.
Parallel connection for ultra-high output in optimal increments
Large electric drives from Rexroth offer individual power outputs of 110 kW to 500 kW in 8 graduated increments and a combined system output of up to 4 MW where as many as 8 units are operated in parallel. Output can also be fine-tuned to the requirements of the application at hand during parallel operation, including at the highest level of output for supply unit and inverter configurations.
IndraDrive ML units can be cooled by air or liquid, and, as required, there are different options available for dissipating and utilizing heat.
Air cooling
Installed in the control cabinet, the air-cooling design is the most cost-effective variant for dissipating heat loss at low output levels. To reduce energy and noise levels, air-cooled IndraDrive ML variants are fitted with fan assemblies that operate based on load. Air cooling via a separate air duct allows the control cabinet to achieve a higher rated protection class, while targeted heat dissipation through an air ducting system is simplified outside the cabinet.
Liquid cooling
Liquid cooling is the most efficient method of dissipating heat, or channeling heat loss. The high inflow temperature of the coolant enables energy to be used effectively in heat recovery systems. Noise levels are also reduced to a minimum. Control cabinets that have a high rated protection type are easy to accomplish.
Application-specific concepts for energy efficient production
The optimal function for lowering consumption and reducing peak loads that are taken into account in almost every application
Energy regeneration into the power grid
Designed to meet the requirements of the target application, the IndraDrive ML always offers the best possible solution for plant operation in an energy-efficient manner. A wide variety of concepts for storing energy in static or rotary configurations as well as a Smart Energy Mode and further options are available for saving energy and reducing peak loads in the power grid.
Mains regenerative power
Feeding surplus energy back into the power grid considerably reduces consumption, especially during generator operation over an extended period. This, in turn, leads to a high-power quality with almost zero harmonic emissions. Regulated DC bus voltage ensures maximum independence from the supply voltage as well as a high level of tolerance for balancing out fluctuations in the voltage.
Smart Energy Mode
Actively regulating the mains inverter in smart energy mode ensures a reliable supply of DC bus voltage that is independent from the mains voltage while utilizing the DC link capacitors for energy storage. The benefits offered by this are particularly apparent when generator and motor power modes are frequently switched as is the case with intermittent acceleration and braking cycles. Peak loads on the line side are also avoided, and average energy consumption is reduced. This improves network compatibility and allows smaller components to be used without compromising machine performance.
Electric and kinetic buffering
Two possibilities exist for buffering large amounts of energy:
DC links
A modular filter concept allows the IndraDrive ML to connect several drives via the DC bus so that energy can be exchanged in multi-axis systems. Central energy storage devices can also be used together.
Regulation of reactive current
Regulating reactive current eliminates the losses produced by the current in the mains connection configuration. Inductive or capacitive consumers can likewise be compensated without the need for additional reactive current compensation systems.
Intelligent energy management at a glance:
Scalable control units and application-specific firmware options allow IndraDrive ML from Rexroth to cover a wide range of standard applications up to and including high-end servo applications that require a high level of dynamic response and precision. We can supply the control unit you need for the application scenario you have in mind. Standardized interfaces, comprehensive firmware functions, integrated motion logic, a host of technology functions, and certified safety technology leave nothing to be desired.
BASIC control units – the scalable standard 
These units constitute the economic solution for all applications involving standard requirements in terms of control quality and interface flexibility. The BASIC control unit
includes a multi-Ethernet, a multi-encoder, and an optional safety technology interface. Two additional interface options allow additional fieldbuses, encoders, or analog/digital I/O extensions to be integrated.
ADVANCED control units – for maximum freedom and performance
These units meet the highest requirements in terms of performance, and a high level of computing power greatly reduces cycle times. Customers can also integrate a Sercos
master to serve as a basis for a drive-integrated control system in addition to the options afforded by a BASIC control unit.
Multi-protocol capable hardware
The protocol used for Ethernet-based interfaces is selected in a software application. Available protocols include Sercos, PROFINET IO, EtherNet/IP, and EtherCat. PROFIBUS and CANopen can also be chosen as optional interfaces.
Multi-encoders
The control units provide base support for all commonly used encoder types thanks to their built-in multi-encoder interface. This gives you maximum freedom in choosing your encoder and motor system.
Flexible firmware configuration
Optimally adapted BASIC and ADVANCED firmware variants are available for the control unit hardware. This firmware can be configured in line with the requirements of your applications:
The basic package is already adequate to perform the majority of standard drive functions, from simple V/f control right through to positioning block mode. Various extension packages provide you with the options of electronic synchronization, additional servo functions or main spindle operation. The freely programmable motion logic with integrated PLC conforming to IEC 61131-3 requirements and of complex machine processes.
Control functions – more options for every application
With IndraMotion MLD, the drive-integrated control system from Rexroth, drive functions, motion control, and processing logic merge to form a modern, open automation platform for modular machine concepts. As a result, you can realize applications independently, without higher-level control.
IndraMotion MLD-S single-axis motion logic
In order to carry out drive engineering tasks that target a specific axis and relieve the load placed on the higher-level control, this system offers the option of moving individual functions to specific drive units. To this end, a wide variety of predefined technology functions can be leveraged, or a separate application can be created as required.
IndraMotion MLD-M multi-axis motion logic
For applications involving a limited number of axes, a Sercos master drive can be used to coordinate up to 9 additional drives. Motion tasks with greater levels of complexity can also be done at the drive level, without the need to integrate the higher-level control.
Open to standards 
Standardized programming languages and the IndraWorks universal engineering framework simplify project planning, programming, parameterization, operation, and diagnosis.
In the process, they integrate valuable know-how directly in the drive to give users an additional competitive edge. Programming is in conformity with IEC 61131-3 in the
following languages:
Standardized modules from the function library in conformity with PLCopen give you access to a multitude of motion functions.
Flexible programming
User-defined programming makes it possible to design applications in a flexible, versatile manner. Innovative drive functions, extensive functions libraries, and process-oriented technology packages combine to form a perfect automation solution.
Predefined functions
Large-scale and sophisticated applications in particular can also be handled with our ready-to-use, predefined technology functions. These applications can then be added to the individual user program or utilized as configurable functions.
Examples of items included in the range:
Productivity Agent
The properties and characteristics of machines and plants change during daily operation as a result of contamination, wear, and other influences associated with harsh industrial environments. Using the Productivity Agent helps operators detect these changes in good time so that they can respond quickly and effectively. To this end, the Productivity Agent includes various online and offline monitoring and analysis functions for mechanicals and processes to improve the performance and availability of the machines:
Certified safety – for protecting man, machine, and work pieces
The extremely short response times of the large electric drives from Rexroth are proof of what modern safety technology can do to protect man, machine, and work pieces, as all motions are monitored right where they start. The Safe Torque Off and Safe Motion functions can also be implemented, depending on requirements.
Safe Torque Off: For safe interruption of applied torque
The Safe Torque Off (STO) safety function reduces the amount of hardware needed as well as wiring costs. Axes equipped with STO ensure a high level of safety without taking the longer route through the higher-level control system. When the STO function is activated, the drive responds with-in milliseconds by interrupting the torque and current supply to the motor connected. This, in turn, prevents the motor from starting up again after having come to a stop. The STO function is certified with Cat. 4 PL e in conformance with EN ISO 13849-1 and with SIL 3 in conformance with EN 62061.
Safe Motion: For safe movements
The optional Safe Motion safety technology offers a comprehensive list of safety functions that range from Safe Stopping through to Safe Travel Moments. Functions requiring no encoder, such as SS1, SS1-ES, STO, SBC, and SDL, are certified with Cat. 4 PL e in conformance with EN ISO 13849-1 and with SIL 3 in conformance with EN 62061. Functions requiring encoder feedback, such as SS2, SOS, SLS, SMS, SMD, SLI, and SDI, are certified with Cat. 3 PL d in conformance with EN ISO 13849-1 and with SIL 2 in conformance with EN 62061.
For logging purposes, IndraDrive uses the safety standard CIP Safety. Signals are simply pulsed in along with the standard data of the Sercos network in real time. Integrating drive, peripheral, and safety buses as well as standard Ethernet communication into a single network simplifies
handling and reduces hardware and installation costs. With CIP Safety on Sercos, up to 64 axes can be operated in a safe manner. The signals can also be provided by way of a zone module for selecting the safety functions. This eliminates the need for a higher-level safety controller, and up to 25 axes can be operated safely.
For more information on the powerful Bosch Rexroth IndraMotion ML, contact one of our application specialists today at 513-881-7000! Hydrotech is the Authorized Bosch Rexroth distributor, integrator, and supplier for Ohio & Kentucky.