DEIF AGC-2 Controller: The Ultimate Guide to Automatic Control and Protection of Generator Sets

2. Load management: fixed power, peak shaving, and load transfer

AGC-2 is not only an emergency power controller, but also an active energy management system.

Fixed power/Base load operation: In this mode, the generator operates in parallel with the mains and always outputs a constant power (set through the 6550 Fixed power setpoint menu). This is often used to reduce the basic load of purchasing electricity from the grid using self owned power plants, or to provide stable base load support for unstable energy sources such as photovoltaics and wind power.

Peak shaving: This mode aims to limit the maximum power that users can obtain from the grid in order to reduce demand electricity bills. Monitor the total power of the imported mains through an external 4-20mA power sensor. When the mains power exceeds the set "maximum mains import power", AGC-2 automatically starts the generator and increases its output to "cut off" the excess peak load. When the mains load drops, the generator is unloaded and shut down.

Load take over: This mode is commonly used for testing or scheduled maintenance. It can smoothly transfer the load from the mains level to the generator, or vice versa. The transfer process can be a synchronous "first connect and then disconnect" to ensure uninterrupted power supply to the load; It can also be a "break and then close" without synchronization, during which the load will be briefly interrupted.

3. Multi machine parallel connection and power management (options G3/G5)

For situations that require high reliability and high power output, AGC-2 supports parallel operation of multiple generator sets.

Option G3 (Load Distribution): Supports automatic sharing of active and reactive power between multiple units through load distribution lines (usually analog or CAN bus).

Option G5 (Power Management): On the basis of load distribution, the "Power Management" function has been added. The system will automatically determine the number of generator sets to be put into or out of operation based on the total load size, and manage the opening and closing of the bus tie circuit breaker to achieve optimal economic operation and redundancy management of the generator sets. This is an ideal solution for building backup power systems for large power plants or critical locations.

Synchronization control technology: the key to achieving seamless grid connection

For situations where parallel connection with the mains or other generators is required, precise synchronization is a prerequisite for ensuring safety and avoiding equipment damage. AGC-2 provides two flexible synchronization methods.

1. Dynamic synchronization

This is the default synchronization method for AGC-2. The principle is to operate the standby generator at a frequency slightly higher than the grid (or bus) (i.e. positive slip frequency). The controller sends a closing command in advance by calculating the slip frequency and the closing time of the circuit breaker, so that the circuit breaker closes at the moment when the voltage vectors coincide (with zero phase difference). The advantage of doing so is that the synchronization speed is fast, and after closing, the waiting unit will naturally bear a part of the load (small positive slip corresponds to the output of active power), effectively preventing reverse power tripping. The relevant settings can be completed in the 2020 Dynamic Synchronization menu.

2. Static synchronization

In this mode, the frequency of the generator to be connected will be precisely adjusted to be almost identical to the grid frequency (with a deviation usually within 50mHz). Subsequently, a phase controller begins to operate, gradually reducing the phase angle difference between the two by adjusting the generator frequency until the closing is completed within the preset "closing window". This method can achieve "zero impact" grid connection, and there will be no significant load fluctuations after closing. It is particularly suitable for connecting load sensitive to impact or connecting no-load transformers (to prevent excitation inrush current). The setting for static synchronization can be found in the menu 2030 Static synchronization.

Fault safety and status monitoring: building multiple protection systems

As the last line of defense for the generator set, the reliability of the protection function is crucial. AGC-2 integrates comprehensive ANSI protection functions and provides systematic fault handling logic.

1. Comprehensive protection function

Electrical protection: including reverse power protection (ANSI 32) (menu 1010), overcurrent protection (ANSI 51) (menu 1020/1030), as well as overvoltage, undervoltage, overclocking, underfrequency and other protections implemented through extended tabs.

Engine protection: Monitor oil pressure, coolant temperature, and fuel level through analog input. In the parameter menu, independent action values (Setpoint), action delays (Timer), enable conditions (Enable: OFF/ON/RUN), and fail classes can be set for each alarm.

2. Fail class logic

The brilliance of AGC-2 lies in its Fail class system. Users can assign different processing methods of 1-6 levels for each alarm: