DEIF AGC-4 Generator Controller Configuration and Debugging Guide

Complete Guide to Application and Parameter Configuration of DEIF AGC-4 Generator Controller

In the fields of diesel generator sets, ship power systems, and emergency power stations, the DEIF AGC-4 controller has become the core device for protection, parallel operation, and power management of medium and large units due to its high integration, flexibility, and powerful communication capabilities. This controller supports various application modes such as automatic mains fault (AMF), islanding operation, fixed power/base load, peak shaving, load transfer, and mains output, and is equipped with rich ANSI protection functions, PID regulators, synchronous logic, and programmable I/O. For on-site engineers, a deep understanding of their functional architecture and parameter tuning logic is key to ensuring the safe grid connection and stable operation of the unit. This article is based on the AGC-4 Design Reference Manual (DRH), which systematically outlines its core functions, protection configurations, regulator principles, and typical additional functions, providing engineers with a practical technical reference.

Product positioning and applicable scenarios

AGC-4 belongs to the DEIF Multi line 2 product family, designed specifically for generator sets, busbars, and grid access. Its basic models include generator protection, speed/voltage regulation control, synchronization, and load distribution. It can be extended to multi machine parallel, multi-channel mains, and energy management systems through optional hardware (such as D1 voltage regulation, G5 power management) and software options. Standard applications include:

AMF (Automatic Mains Failure): After the mains voltage drops, the unit automatically starts and closes, and returns synchronously after the mains power is restored.

Island operation: Independently loaded, started and stopped according to digital or timed instructions.

Fixed power/base load: When connected to the grid, it outputs constant active power and participates in grid support.

Peak shaving: When the imported power of the mains exceeds the limit, the unit supplements the difference.

Load transfer: Smooth transfer of mains power load to the unit to achieve independent power supply.

Municipal power output (fixed power output): To output or input constant power to the grid.

The system supports three-phase, phase separation, and single-phase measurement, with a direct voltage input range of 100-690V AC and a frequency of 30-70Hz, suitable for mainstream global power grid standards.

Measurement system and rated parameter settings

The AGC-4 factory default three-phase four wire measurement can be switched to phase separation or single-phase mode through the jump menu 9130, and the rated voltage (menu 6004), CT ratio (6043/6044), and bus voltage transformer parameters (6051~6053) can be adjusted accordingly. Key point: If there is no PT on the busbar, set 6054 to "BB Unom=G Unom" to ensure that the busbar is rated to follow the generator. The controller supports four sets of rated parameter sets (6001~6036), which can be dynamically switched through digital input, AOP or M-Logic. It is particularly suitable for mobile power stations or scenarios that require seasonal adjustment of protection settings.

Voltage scaling (9030) can be set to 100-25000V by default. If the on-site voltage exceeds this range, the input range needs to be modified with the master password permission to ensure that the primary value is displayed correctly.

Standard Protection Function (ANSI)

AGC-4 provides complete generator and bus protection, all of which are timed and can independently set the starting value, delay, output relay, and fail class. The fault level ranges from "warning" to "shutdown/trip", with a total of 8 levels, determining the action behavior after the alarm (such as load shedding, trip, cooling shutdown, locking start).

Main protection list:

Reverse power (32): 2 segments to prevent the prime mover from being dragged by the power grid.

Overload (32 inverse time limit): 5 segments, delayed action according to power percentage.

Overcurrent (50/51): 6-stage fixed time limit+inverse time limit, can be used in conjunction with voltage dependence (51V) for short-circuit current attenuation scenarios.

Overvoltage/undervoltage (59/27): Generator 2-stage overvoltage, 3-stage undervoltage; Bus 4 sections overvoltage and 5 sections undervoltage, both support phase to phase or phase to phase measurement selection (1201/1202).

Over/under frequency (81): Generator 3 sections, busbar 5 sections, frequency deviation detection.

Voltage/current imbalance (60): detects three-phase asymmetry and protects windings from overheating.

Demagnetization/overexcitation (40/32RV): Prevent phase instability by limiting reactive power.

Non essential load trip (NEL): There are 3 groups in total, which can cut off secondary loads according to current, frequency, or power thresholds to prevent system collapse.

Setting prompt: Taking reverse power as an example, the typical setting value is -5%~-15%, with a delay of 5-10 seconds, and the fault level is set to "trip+stop"; Overcurrent protection needs to be coordinated with higher-level protection, commonly using a six segment reverse time limit line (110%/5s~200%/0.5s) to achieve selective tripping.

PID regulator and speed/pressure control

The AGC-4 is equipped with an independent PID controller for speed regulation (GOV) and voltage regulation (AVR, with option D1), which respectively manage frequency, power, active power distribution, voltage, reactive power, and reactive power distribution. The parameters of each controller (Kp, Ti, Td) can be adjusted from menu 2500 to 2690.

1. Proportional, integral, and differential effects

Kp (proportional gain): Affects response speed, and excessive Kp can cause oscillation. It is recommended to fully utilize the output range (such as 0-20mA) to avoid large adjustments caused by small deviations.

Ti (integration time): Eliminating static error, the smaller the Ti, the stronger the integration effect, but if it is too small, it is prone to oscillation. When Ti=0, the integral is closed.

Td (differential time): improves dynamic stability and is beneficial for fast disturbances (such as static synchronization), usually set to 0 or very small.

2. Load distribution controller (load sharing)

In parallel mode (options G3/G5), the load distribution controller takes over frequency and power regulation. The weight factor of "PWEIGHT" (2544) determines the strength of power regulation: 100% indicates full effort to eliminate power deviation, and lower values prioritize frequency stability. In actual debugging, if large power fluctuations are found during parallel operation, the PWEIGHT can be appropriately reduced or the Kp of the frequency PID can be reduced.

3. Relay output adjustment

If relay pulse output (instead of analog) is used, the "ON time" (minimum pulse width) and "Period time" (period) need to be set. The regulator will automatically adjust the duty cycle according to the deviation size. When the deviation is large, the pulse will be turned on or long, and when the deviation is small, the pulse will be short. After entering the dead zone, the regulation will stop.

4. Drooping mode

When parallel connection with existing droop units is required, frequency droop (2514) and voltage droop (2644) can be enabled, with a droop of 0-10%. The droop adjustment can be activated through M-Logic and is suitable for old units that cannot provide constant speed adjustment.

Synchronization principle and parameter adjustment

AGC-4 supports two modes of synchronization: dynamic synchronization and static synchronization (selected from menu 2000).

1. Dynamic synchronization (default)

Grid connected units catch up with the bus phase at a certain slip frequency (usually positive, slightly faster than the bus). Key parameters:

Sync dfMAX/dfMIN (2021/2022): Maximum allowable positive/negative slip, typical values+0.3Hz/-0.3Hz.

Sync dUMAX (2023): Maximum allowable voltage difference, typically 5%.

Sync tGB/tMB (2025/226): The inherent closing time of the circuit breaker is used to send out closing pulses in advance.

The dynamic synchronization speed is fast and suitable for load switching, but it is necessary to ensure that the slip is positive to avoid reverse power tripping after closing.

2. Static synchronization

First, adjust the frequency to almost the same frequency as the bus (deviation<50mHz), and then fine tune the phase angle by the phase controller (2070). When the phase angle enters the "closing window" (2033, ± 0.1~20 °), issue a closing command. Static synchronous impact is small, but the adjustment is slow, suitable for applications that are sensitive to impact.

3. Excitation before closing (CBE)

This function allows the unit to close without excitation, and then switch on excitation after closing, which can significantly shorten the grid connection time, especially suitable for black start or emergency scenarios. MPU or EIC speed signal needs to be configured, and parameters such as closing speed threshold (2251) and excitation start delay need to be set. When CBE fails, a 2270 alarm will be generated.

Additional functions and logical configuration

AGC-4 has a large number of built-in auxiliary functions, significantly enhancing on-site adaptability:

1. Idle Running

Used in low-temperature environments, start at idle speed first, and then increase speed after warming up or reaching the temperature standard. By using digital inputs of "low speed" and "temperature control" in conjunction with a timer (6290), the turbocharger can be protected.

2. Fan Logic Control

Control up to 4 fans, start them in stages according to the cooling water temperature (Pt100 or EIC), and automatically rotate the running time to balance wear. Fan fault feedback can be monitored through digital input.

3. Derate

When the ambient temperature rises or the cooling capacity decreases, the maximum output power of the unit (6250~6266) will be automatically reduced. The derating can be triggered based on 4-20mA, Pt100, EIC temperature, or M-Logic, and the lowest value can be taken for the three independent derating groups.

4. Non essential load trip (NEL)

According to the unit current or bus frequency, cut off the secondary load in three groups to prevent overload shutdown. Each group can individually set the current/frequency threshold and delay.

5. Engine heater and fuel pump logic

The heater automatically starts and stops based on the cooling water temperature when it is in the shutdown state (6320); The fuel pump maintains the service fuel tank level (6550) based on the level sensor (RMI or 4-20mA) and has a fuel injection check timeout alarm.

6. Circuit breaker management

Supports pulse, continuous (NE/ND), and compact circuit breakers, with configurable closing spring loading time (6230/7080) and "shake out circuit breaker" mode to suppress false alarms when the circuit breaker is in the test position.

7. Battery testing and asymmetric monitoring

Battery testing can be conducted manually or automatically (periodically) to check the load-bearing capacity of the starting battery; The battery asymmetry test (6430) determines the degradation of a single battery by comparing multiple input voltages.

M-Logic and Programmable Input/Output

M-Logic is a simple logic tool built into AGC-4 that can be configured through PC software without the need for additional options. It allows the combination of digital input, alarm events, operating status, and other conditions to output to relays, mode switching, or PID control commands. For example, M-Logic can be used to implement logic such as "activating the fan while the engine is running" and "forcing the maximum speed during the cooling phase".

The digital input function is rich, including remote start stop, mode switching, locking and closing, manual speed/voltage regulation, battery testing, circuit breaker spring loading feedback, etc., all of which can be allocated according to needs. Analog input (4-20mA, 0-40V, Pt100) can be scaled and set with alarms, supporting cable breakage detection.

Typical troubleshooting and maintenance recommendations

Synchronization failure: Check the slip, voltage difference, and circuit breaker closing time settings; Ensure that the phase of the bus voltage is correct (see 9141 phase compensation).

Unit startup failure: Check the startup relay, fuel solenoid valve, operation feedback signal (digital/MPU/frequency), and verify the number of startup attempts (6190) and startup preparation timer (6180).

Uneven load distribution: Adjust PID weights and droop parameters, check the shielding and termination of load distribution lines (if there are analog quantities).

Alarm misoperation: Confirm whether the fault level setting is too strict, and use the "suppression" function to delay the alarm until the unit runs stably before it takes effect.

Data loss: Regularly backup parameter files (. usw) through PC software, and be sure to perform a backup (9230) before replacing the internal battery.