Grid code compliance right out of the box

Grid codes specify a predefined power ramp that defines how quickly a power source can ramp up to full power output after synchronizing to the grid. The AGC-4 Mk II can control the ramp of any connected power source.

Reducing grid disturbances

Grid code requirements are intended to lessen disturbances on a grid with several connected power sources. With multiple power-producing devices, it becomes an important consideration how they enter the grid to contribute power. In the past, ramp requirements were less stringent, and power sources could synchronize and dump their load on the grid with very steep ramp times. With AGC-4 Mk II, grid code requirements for ramping are met.

Preventing synchronization when needed

The controller also prevents the power source from connecting and synchronizing with the grid if it is not allowed. When grid frequency increases because more energy is being produced, the AGC-4 Mk II automatically prevents synchronization which would have contributed more energy to the system and exacerbated the frequency issue. When grid frequency drops because of production disturbances, power source synchronization is also prevented because other power sources need to ramp up and stabilize the grid.

The AGC-4 Mk II provides highly accurate synchronization, synchronizing the controlled power source with the grid at an accuracy of 10 mHz. While the old AGC-4 was also capable of achieving an average of +/- 10 mHz of accuracy, it did so within a much narrower temperature range whereas the AGC-4 Mk II delivers consistently accurate synchronization performance.

Accuracy reduces grid disturbances

Accurate synchronization means less impact on the grid when the power source is connected, as the AC waveforms can be approximated very closely to one another. This reduces fluctuations and disturbances for your customers. The accurate performance of the AGC-4 Mk II is possible thanks to its powerful processors.

The AGC-4 Mk II supports various communication protocols that can be used in conjunction with grid code compliance. Not all grid codes are specific when it comes to type of protocols.

The American grid code IEEE 1547^TM – 2018 requires power producers to use one of three mandated standard communication protocols to interface with the grid. The AGC-4 Mk II uses the SunSpec Modbus protocol which enables multi-vendor interoperability for manufacturers of solar inverters, energy storage devices, trackers, meters, and other devices.

Logical choice for PV operators

We consider the SunSpec Modbus protocol to be the market leader in green and renewable energy. The protocol is a logical choice for power producers and microgrids that rely on PV plants. It is continuously updated and covers all solar inverters and many other commercially available distributed energy resources (DERs).

DEIF is a member of the SunSpec Alliance.

The AGC-4 Mk II is able to limit reactive power production relative to actual power production. In this way, the controller not only contributes to grid stability according to the grid code in question; it protects the generators that parallel with the grid—a very important benefit for equipment owners who need to ensure stable grid support and protect their own assets in the process.

Easy and flexible configuration

The reactive power limiting feature is based on the actual steady-state reactive power capability curve of the connected generator and can be configured in relation to active power (P/Q diagram) or apparent power (S/Q diagram). Using the utility software of the AGC-4 Mk II, the user can easily define curves for importing and exporting reactive power, with six coordinates for each curve.

Restricting reference or regulating cos phi

If the set point for reactive power is outside the limiting curve, the controller restricts the reference to the regulator. When the reactive power set point moves inside the limiting curve, the controller regulates reactive power (or cos phi). Protections can also be activated to disconnect the generator from the grid, and alarms can be configured for exceeding the capability curve under or over the excitation limit.