DEIF AGC-4 Generator Controller Configuration and Debugging Guide

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.