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Smart Grids: iNES - Intelligent Distribution Grid Management System

Smart grid system platform

iNES – the intelligent distribution grid management system, is the first integrated system solution and smart grid system platform for decentralised grid management and grid automation.

Video: What can iNES offer to you?

The Map to a smarter grid

The Map to a smarter grid (click to enlarge)
The Map to a smarter grid (click to enlarge)

iNES intelligent distribution grid management is the first true smart grid platform that enables the implementation of individual visions of a smart grid. iNES makes it possible to expand an existing local grid with a modular, autonomous measurement and control system. As a result, the entire infeed and load flow situation can be controlled in real time, and critical deviations can be fixed in a targeted manner if required. In 2013, iNES received the Smart Grid Award (Hessian State Prize for intelligent energy, grid section) and an award from the DKE/VDE.

Good to know!

iNES is not a stand-alone solution, but an open system platform which integrates third-party components into the system. As a result, it is on track to establish a standard for the smart grid.


iNES system integration/ system platform - find out more!

iNES makes it possible to upgrade a conventional low-voltage grid to a true smart grid.

The modular design of the iNES system makes it possible to implement an individual, decentralised smart grid in existing local grids at different expansion stages: This can range from an intelligent local grid substation with substation monitoring, to grid monitoring or even decentralised grid automation, which makes it possible to control the entire infeed and load flow situation in real time, and to fix critical deviations in a targeted manner if required.

The universal control concept includes the integration of all control components for voltage, reactive power and active power available on the market. As a result, iNES integrates and controls a wide range of components, such as variable local grid transformers, linear regulators, inverters, EEG (Renewable Energy Sources Act) producers (PV, wind, biomass, biogas), storage and particularly powerful consumers (e.g., cooling equipment, heat pumps).

iNES also forms the basis for the provision of ancillary services: Detailed statements on the available network capacity are possible, due to knowledge of up-to-date power flows. In addition, iNES generates further added value for business management and asset management.

The iNES advantages

As iNES works autonomously, existing infrastructure can continue to be used and is only supplemented with technical components. Overloads and large fluctuations in load are thus no longer part of network management and planning.

A measurement and control system with this level of intelligence can intercept production peaks and thereby avoids the need for investments in grid expansion or moves this far into the future. In addition, iNES offers added value, e.g. in regard to the provision of ancillary services, grid state detection and distributed congestion management, which represents an important contribution for system and grid management, as well as operation.

  • Automated grid state detection for the control of the growing range of control elements (e.g. RONT, linear regulators, storage and power inverters)
  • Complete transparency of all electrical processes in the grid for operation and asset management
  • Secure and autonomous operations at the low-voltage level
  • Can be integrated into existing grid structures, providing a cost-effective alternative to grid expansion
  • Modular design which can adapt to individual needs and be expanded at any time – from monitoring local grid substations and monitoring the low-voltage grid up to autonomous automated control of energy consumers and generators
  • Supports central infeed management (cascade control) as well as independent active power management
  • Simple operation of RONT, linear regulators, storage or power inverters

The iNES system elements

sBOX (control)

Independent monitoring and control through identification of the grid state and targeted control of generation/ consumption systems.

GSI

Grid State Identification

IGC (Intelligent Grid Control)

How does IGC work?

The grid state is calculated as part of the periodic online calculations of mBOX and aBOX values that are transmitted to the sBOX (Smart RTU) through direct measurement. The results of this calculation are transferred to the IGC (Intelligent Grid Control) to calculate a possible optimal strategy for action. Actions and their impact on the grid are simulated and evaluated within a calculation cycle. The result with the highest probability of success is then submitted to the appropriate actuator for execution. In the framework of the subsequent measurement, calculation and control cycle, the consequences of this action are measured, analysed, and either continued or if necessary replaced by a better strategy determined in the IGC.

The control algorithm follows a three-step concept. First, an attempt is made to counter an infringement of the voltage range through controlling a variable local grid transformer or a linear regulator. If this is not successful, the reactive power is adjusted in the second step. An adjustment of the active power or load control is only performed in the third step. The following example shows the adjustment of a PV system: If the control activities of the first two steps are not successful, the active power is adjusted - this can be done in steps of 90%, 60%, 30% and 0%, or be continuously variable.

Using the iNES reporting function, the exact data with time stamp can be used for verification in these cases, forming the basis for compensation payments to the plant operator.

mBOX (measurement)

Acquisition/transmission of actual values of various grid nodes of the NSP system.

aBOX (actuators)

Acquisition/transmission of actual values and control of decentralised generation and consumption systems.

iNES Map

The values measured by iNES are loaded into the iNES map web application, for the subsequent review of the grid conditions. This provides you with a comprehensive analysis tool, which can be consulted for asset management and network planning, among other tasks.


Screen layout and operating elements

The user interface of iNES map consists of the following areas: 1: Overview map, 2: Map tree, 3: Tool bar, 4: Map display, 5: Module tab, 6: Data area. The user interface of iNES map consists of the following areas: 1: Overview map, 2: Map tree, 3: Tool bar, 4: Map display, 5: Module tab, 6: Data area.
The user interface of iNES map consists of the following areas: 1: Overview map, 2: Map tree, 3: Tool bar, 4: Map display, 5: Module tab, 6: Data area. The user interface of iNES map consists of the following areas: 1: Overview map, 2: Map tree, 3: Tool bar, 4: Map display, 5: Module tab, 6: Data area.

Map options

You can adjust the map view according to your requirements. The following options are available to do so:

 1: Overview map with the currently displayed section (rectangle with a red dotted border), 2: Selection of background map (maximum zoom possible if "no background" is selected) and the elements shown in the map, 3: Move map, 4: Zoom control and current zoom.
1: Overview map with the currently displayed section (rectangle with a red dotted border), 2: Selection of background map (maximum zoom possible if "no background" is selected) and the elements shown in the map, 3: Move map, 4: Zoom control and current zoom.

Communication

The communication structure of the iNES system solution consists of two subsystems, which are addressed from the sBOX:

  • Control centre communications: with a superordinate system,
  • Field communications: with a subordinate system (decentralised transmitter).

Communications with a subordinate system:

The communication of the sBOX to the subordinate decentralised transmitters is structured using broadband powerline (BPL) technology. This establishes a communication structure that is capable of real-time communication via the electricity grid.

Communications with a superordinate system:

The communication from the sBOX to a superordinate remote/ control room is structured using an encrypted VPN connection via wireless or DSL. If the local grid substation is equipped with a control cable to the control room, this connection can also be used with serial modems or ADSL modems.

Addendum:

Communication over serial/ ADSL modems refers to measurements, setpoints, control commands! A wireless or DSL connection is required to retrieve archives from a substation or to establish remote work access. The communication channels are encrypted!

Gradually upgrading the local grid with ‘intelligence’

Gradually upgrading the local grid

Substation monitoring

In a first step towards a smart grid, the local grid substation monitoring function is added to existing local grids, which captures utilisation and substation status data.

In addition to our sBOX, sensors are also installed inside the LGS for substation monitoring. This makes it possible to capture actual values - such as current, voltage, power and temperature - from the LGS with a time stamp, archive them and transfer them to the superordinate control system.

During the first expansion stage of the iNES system solution, actual current and voltage values are measured in the local grid substation (LGS) on the low-voltage side and transferred in summarised form (such as signal lights) to a superordinate control or diagnostic system, for the identification of critical electrical conditions at the local grid substation.

System components:

  • iNES sBOX
  • Sensors within the LGS
  • Communications link to superordinate diagnostic/control systems

The aim is to assess and monitor the capacity utilisation of local grid substations (LGS) by sensors within the LGS.

Benefits

  • Reduction of downtime
  • Overview of the substation utilisation
  • Load flow direction detection in the LGS
  • Logging and archiving of the actual values
  • Simple display of the substation status with a simple traffic light system

Grid monitoring

Building on this, measuring sensors and control units can be placed in the distribution grid at key grid nodes in order to monitor and manage the entire local grid. The data from the decentralised measurements is consolidated in the local grid substation and then processed in a periodic online calculation (grid state identification) of the current network state, based on a limited measurement topology.

The second expansion stage includes substation monitoring and expands this with additional actual current and voltage values at individual nodes and strands in the low-voltage grid area after the local grid substation. Substitute values for grid nodes and strands that are not being measured are created on this basis. Measured actual values and calculated supplementary values form together the basis for a power flow calculation in the low-voltage grid. The results of this calculation are transferred in summarised form (such as signal lights) to a superordinate control or diagnostic system, for the identification of critical electrical grid conditions in the grid area.

The aim of grid monitoring is to increase the system observation to include the electrically active processes in the upstream grid.

System components:

  • iNES sBOX, mBOX, GSI
  • Sensors within the LGS
  • Communication of iNES sBOX to the superordinate diagnostic/control system 
  • Communication between the substation with iNES sBOX and network nodes with iNES mBOX

In grid monitoring, in addition to the fitting of the LSG with sBOX and sensors, individual network nodes (cable boxes) are equipped with sensors (mBOX). The selection of the network nodes to be upgraded takes place using our configuration tool, which reduces the number of the data points from existing GIS data to a minimum. This means that, in addition to the actual values from the LGS, the actual values of the diverse network nodes in the low-voltage network (power, voltage, current etc.) are captured centrally in the sBOX and transferred to the superordinate control system including time stamps.

Only a maximum of 10% to 15% of the grid nodes need to be equipped with sensors in order to be able to automatically register the grid status and potential changes in the grid topology.

Benefits in addition to low-voltage substation monitoring:

  • Identification of critical and/or overloaded power districts (bottleneck detection)
  • Improvement of planning criteria via knowledge of grid status history
  • Overview of substation and grid utilisation
  • Load flow direction detection in the local grid substation and low-voltage network
  • Logging and archiving of the actual values
  • Simple traffic light system for displaying the substation status

Grid automation

The third expansion stage makes it possible to achieve autonomous, smart and secure grid management, which includes the selection of the optimum action strategy for voltage, active power and reactive power control in real-time. This is achieved in combination with the innovative iNES calculation algorithm (intelligent grid control) and by equipping central suppliers and consumers with actuators.

The final expansion stage builds on the results of the grid monitoring. In order to effectively resolve the critical electrical grid conditions that were determined in expansion stage 2, automated recommendations are calculated and countermeasures are initiated independently. Again, the results of the power flow calculation as well as the recommendations and countermeasures to resolve critical electrical grid conditions are transferred in summarised form (such as signal lights) to a superordinate control or diagnostic system.

System components:

  • iNES sBOX, mBOX, aBOX, GSI, IGC,
  • Sensors within the LGS and on the network nodes
  • Communications with the superordinate diagnostic/control system
  • Communication between the LGS with iNES sBOX and network nodes with iNES mBOX or generation and consumption facilities with iNES aBOX.

Grid automation complements the grid monitoring scheme with actuators (aBOX) and our load flow and control algorithm, ‘Intelligent Grid Control’ (IGC). The actuators are installed in individual generation and consumption facilities, enabling
the control and regulation of power generation and consumption facilities in connection with our IGC algorithm. The placing of the actuators (aBOX) and the installation of the IGC on the sBOX creates the potential for protecting the low-voltage network from overloading situations, actively and autonomously.

The aim: Autonomous monitoring and control of the low voltage network by identification of the network status and targeted control of generation and consumption facilities.

Benefits in addition to grid monitoring:

  • Secure and autonomous operations at the low-voltage level
  • Reduction/delay of cost-intensive/conventional investments (e.g. refurbishment of the network, replacement of local substation transformers etc.)
  • Better use of existing network capacity
  • Self-regulating local system with optional connection to the control center

Medium-voltage substation monitoring (MV)

With a new generation of cable assemblies, the potential for substation monitoring is now created. This allows the complete automation of the grid in combination with the iNES components. The aim is an accurate and continuous measurement in the medium-voltage network.

Benefits in addition to grid automation:

  • Very high measurement accuracy for power and voltage in the medium-voltage grid
  • Factory calibrated – no need for later costly and elaborate recalibration
  • Quick and easy installation
  • Retro-fitting – no changes required to the substation