A modern generating plant does not only produce electrical energy, it must actively contribute to the stability of the power grid. The Grid Code defines how the plant responds to voltage and frequency changes, how it executes system operator commands and how it behaves during grid disturbances.
Connecting solar plants, wind farms, battery energy storage systems (Battery Energy Storage System, BESS), small hydro plants, combined heat and power (CHP) units and generator sets requires coordinated operation of protection, control and communication at the connection point.
SYMAP® Compact+ GC combines numerical protection, the Power Plant Controller (EZA-Regler), Grid Code functions, communication, metering and event recording in one device, according to the selected configuration and Order Code. SYMAP® Compact+ GC is the device at the connection point (Point of Connection, PCC), while control of individual inverters, turbines or generators is realized via the respective executing controllers.
A traditional grid connection typically requires multiple dedicated devices for protection, plant control, synchronization, metering and communication. Depending on the selected Order Code and certified configuration, SYMAP® Compact+ GC integrates these functions into a single device, reducing engineering effort, wiring, testing, commissioning, long-term maintenance complexity and overall project cost.
| Traditional (several separate devices) | SYMAP® Compact+ GC |
|---|---|
| Protection of power system elements | included |
| Mains decoupling (NA protection) | included |
| Plant controller (Power Plant Controller, PPC), P(f) and Q(U) | included |
| Q-U / reactive support | included |
| Dynamic grid support (Fault Ride Through / Low Voltage Ride Through, FRT/LVRT) | included (27T/27Q) |
| I/O controller and expansion | included (Extension Board System, EBS) |
| Communication interface to the supervisory system (Supervisory Control and Data Acquisition, SCADA), remote via gateway and remote terminal unit (Remote Terminal Unit, RTU) | included (local: IEC 61850, Modbus TCP/RTU, IEC 60870-5-103, Profibus DP; toward upper-level systems via gateway/RTU, IEC 60870-5-101/-104) |
| Separate event and fault recorder | included (Common Format for Transient Data Exchange, COMTRADE) |
Grid Code requirements (voltage, power, Q(U), FRT, mains decoupling) are measured and assessed at the grid connection point (PCC / Netzanschlusspunkt). Compact+ GC measures quantities at that point and coordinates the plant behaviour through executive devices (automatic voltage regulator AVR, governor, inverter).
Internal flow: the device continuously measures, applies protection and Grid Code logic, and acts through outputs and communication. All in one device, per the selected certified configuration.
Interactive block diagram. Click any block or function for details; the active connections animate.
Choose a scenario to see how data moves through the plant. The flow animates step by step.
Compact+ GC does not replace SCADA, AVR, governor or inverter; it connects and coordinates them within a clearly defined scope. Compact+ GC computes the required reference values and, via the appropriate communication or hardwired interfaces, passes them to the AVR, governor or inverter controllers, which perform the physical regulation of the generating plant.
| Component | Role |
|---|---|
| SCADA / supervisory system | Operator interface, visualization, archiving, sending setpoints and commands; does not execute local protection |
| SYMAP® Compact+ GC | Central Grid Code interface: protection, NA protection, plant-control logic, measurements, I/O, communication, recording; translates the grid requirement into actions and evidence |
| AVR / governor | Voltage and speed/prime-mover control; receives references/commands from Compact+ GC |
| Inverter firmware (PV/BESS) | Converter-level control and internal protection; receives setpoint / enable / trip from Compact+ GC |
| Dedicated PPC (large plants) | Plant-level optimization for many inverters; Compact+ GC remains the protection/Grid Code interface at the connection |
Modern connections require the plant to stay connected and support the grid during disturbances instead of disconnecting immediately.
Time-dependent undervoltage (ANSI 27T) with up to 10 characteristic points provides LVRT/FRT; the high-voltage ride-through is a separate function, ANSI 59T (HVRT). The plant stays connected during short voltage disturbances.
Reactive power feed-in during mains undervoltage to support voltage.
Active and reactive power according to defined characteristics and operator commands.
The functions shown represent typical device capabilities. Availability of individual functions depends on the selected device configuration and the order code.
Local / station SCADA
Compact+ GC connects directly, via IEC 61850 (MMS/GOOSE), Modbus TCP/RTU and IEC 60870-5-103.
Upper-level systems (SCADA / EMS / DMS)
Realized via a separate gateway / RTU / PLC that aggregates data from the plant devices and talks to the upper-level system over IEC 60870-5-101 (serial) or -104 (TCP). Compact+ GC connects to that gateway/RTU locally, via IEC 61850 or Modbus TCP.
Compact+ GC is not the complete SCADA; it provides measurements, status, commands and evidence, with local protection and Grid Code logic. The certified (FGH type-tested) interface for EZA-Regler setpoints is Modbus TCP / Profibus DP; IEC 60870-5-104 (server variant) is part of the wider Compact communication framework per Order Code, while communication with the upper-level systems is handled by a separate gateway/RTU/PLC, not by Compact+ GC itself. Exact protocols depend on the Order Code.
SYMAP® Compact+ GC holds an FGH component certificate for the plant-controller (EZA-Regler) function per VDE-AR-N 4110:2018-11 and 4120:2018-11; protection functions are subject to separate FGH certificates. Certificates are valid only within the approved configuration. For each project, check the current certificate scope, hardware/firmware version, Order Code and parameters. Full plant compliance is achieved by coordinated behaviour of all components at the connection point and demonstrated through the prescribed commissioning process.
One integrated device supports every stage of the plant lifecycle, from operator requirements and engineering to commissioning, long-term operation and maintenance.
One integrated device reduces the number of components, simplifies FAT and SAT testing, reduces wiring effort and speeds up diagnostics across the entire plant lifecycle.
Designing the plant with advanced Grid Code functionality from the beginning increases flexibility and can reduce future engineering effort if grid connection requirements evolve.
The Republic of Serbia, as a contracting party of the Energy Community, is developing its regulatory framework for the connection of generating plants in line with the European network codes, including Commission Regulation (EU) 2016/631, the Network Code on Requirements for Generators (NC RfG).
VDE-AR-N 4110 (medium voltage) and VDE-AR-N 4120 (high voltage) are proven technical rules based on the NC RfG and are often used as a reference basis when designing and implementing Grid Code functions.
Designing plants with support for advanced Grid Code functions today can contribute to greater readiness for future regulatory requirements, while reducing the need for subsequent hardware changes, additional wiring, repeated testing and additional investment.
For every project, the applicable regulations of the Republic of Serbia and the technical requirements of the responsible system operator must be applied.
A device proven against the German basis reduces future-compliance risk when domestic rules take effect.
The same logic (protection + control + dynamic support + evidence) is already required in the EU framework and will be required domestically.
Measurements, control and COMTRADE records needed to demonstrate compliance at connection.
Protection/Grid Code interface at the connection; setpoint/enable/trip to the inverter layer.
EZA-Regler at the park connection: Q(U)/Q(P)/cos φ, P(f), FRT and evidence; the FGH type test covers the control path for wind plants and the control of multiple units at a common NAP.
Protection, synchronization and Grid Code control alongside the existing governor/AVR; a strong retrofit case.
Fewer separate devices in the generator cabinet; P/Q/PF control and communication to SCADA.
SYMAP® Compact+ GC is a device for numerical protection, generating-plant control (Power Plant Controller, PPC / EZA-Regler) and Grid Code functions. Depending on the configuration it combines protection, mains decoupling (NA protection), automatic synchronization, measurement, communication and control of the plant executing devices through active and reactive power, voltage and frequency regulation (P, Q, U, f).
Yes. Within the approved configuration, SYMAP® Compact+ GC simultaneously executes numerical protection, generating-plant control (Power Plant Controller, PPC / EZA-Regler), mains decoupling (NA protection), automatic synchronization and Grid Code functions.
The Grid Code is a set of technical rules defining how a generating plant must behave when connecting to and operating in the power grid.
They define MV/HV connection requirements and ensure secure grid operation.
No. SCADA remains the supervisory system; Compact+ GC exchanges data with it bidirectionally: it sends measurements, alarms and events, and receives commands and setpoints.
No. The AVR regulates voltage; Compact+ GC may provide references.
No. The governor regulates speed; Compact+ GC may provide references.
Compact+ GC controls the generating plant by sending reference values and commands to the executing devices (e.g. inverter controllers, the AVR or the governor), in line with the project architecture.
Plant operation is determined by the system operator requirements, the applied Grid Code, the project documentation and the settings of the approved device configuration.
Local protection remains active. Fail-safe behaviour is project-specific.
No. Only to the approved certified configuration.
The ability of the plant to stay connected during specified voltage disturbances: LVRT via ANSI 27T, HVRT via ANSI 59T.
Frequency-dependent active power control.
Voltage-dependent reactive power control. Q(P) and cos φ are also supported, per operator requirement.
Depending on the configuration, SYMAP® Compact+ GC measures voltages, currents, active, reactive and apparent power, frequency, power factor (cos φ), energy and other electrical quantities required for protection, control and analysis of the generating plant operation. It also monitors the states of binary inputs and outputs.
At device level (local/station): IEC 61850 (MMS/GOOSE), Modbus TCP/RTU, IEC 60870-5-103 and Profibus DP; IRIG-B for time synchronization; CAN-Bus for internal communication between modules. Communication with the upper-level systems (SCADA, EMS, DMS, system operator) is not handled by Compact+ GC itself but by a separate gateway, RTU or programmable logic controller (Programmable Logic Controller, PLC), which aggregates data from the plant devices and exchanges it per the project architecture and protocols (e.g. IEC 60870-5-101 or -104). Availability depends on the Order Code.
Yes, with existing AVR, governor, PLC, inverter and SCADA systems.
It combines protection, Grid Code functions, communication and signal handling in one device, within the configuration.
Depends on the project; in some plants yes, in others it acts as the Grid Code interface at the connection.
No. It coordinates assigned functions; overall control may involve SCADA, EMS, DCS, PLC or PPC.
MV and HV grids (VDE-AR-N 4110/4120): PV, wind (wind farms), BESS, hydro, CHP and gensets. The exact application depends on the configuration and measuring inputs.
Through the relevant voltage, frequency and other protection functions, selected per project and operator requirement, which disconnect the plant on an impermissible grid condition.
Demonstrating compliance with Grid Code requirements is carried out in line with the applicable regulations and the procedures of the responsible system operator. Depending on the project, this may include device and plant certification, functional tests during commissioning, and documenting the measurement and test results. SYMAP® Compact+ GC supports this process by providing the records needed for analysis and documentation of plant operation, including:
Where applicable, certification applies to the approved device configuration, with hardware, firmware, Order Code and the relevant parameters matching the certified configuration.
Yes, on operator request, in steps (e.g. 100/60/30/0%) down to disconnection. The obligation and threshold depend on the responsible operator.
Not necessarily. The device architecture allows a failure of the HMI, communication or EBS module not to mean a loss of the core protection functions by itself. The final behaviour depends on the fault type, the device configuration and the applied fail-safe logic. Note: on a loss of the device auxiliary supply, all binary outputs go to the de-energized state.
| Compared with… | Compact+ GC advantage |
|---|---|
| a classic protection relay | Combines protection with control, I/O, communication and evidence in one configuration |
| a dedicated PPC (large PV/BESS) | Protection-first; strong when protection, Grid Code logic, I/O and evidence must be close together |
| a genset controller | Stronger as MV/HV protection and Grid Code interface (ANSI protection, FRT, reactive support, evidence) |
Request the technical datasheet or a connection consultation. We propose a configuration for your rating, site and operator requirements.
Request a consultationDiscuss your project with our engineersDownload AreaNote: functions, interfaces, certifications and limits depend on hardware and firmware version, Order Code, parameter set and the approved certified configuration. This page does not replace the official VDE-AR-N standards, project-specific certification documentation or the SYMAP® Compact manual.
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