The role of generator governor
The generator governor plays a crucial role in maintaining a stable speed of the diesel engine. During load changes, the speed of the engine may also change. Without the governor adjusting accordingly, the engine could eventually stop running or sustain damage due to excessive centrifugal force. Its primary function is to ensure that the engine maintains a consistent speed, and it also helps maintain the minimum and maximum speed to prevent stalling or mechanical damage.
The role of generator governor in power-frequency regulation?
The generator governor’s critical role in generator power-frequency adjustments is to automatically modify the steam or water intake of the generator set’s turbine within the technical conditions, whenever the system frequency changes, to increase or decrease the generator’s output. This mirrors the correlation between frequency changes and the generator set’s output shifts, known as the static frequency characteristics of the generator speed control system. The system frequency is automatically regulated based on the disparity between required and actual frequencies.
What are the common faults of generator governor and how to solve them?
The generator governor is a crucial accessory for power generation, and failure can result from various situations, as mentioned below along with their corresponding exclusion methods:
- Over-speeding (sudden failure of the governor, leading to speeds exceeding 110% of the calibrated speed)
Elimination Method: Imposing an emergency stop and disconnecting the fuel supply, stopping the oil or shutting down the air intake, and other measures are required to stop the diesel engine.
- Jammed governor gear lever or throttle lever
Removal Method: Inspecting the parts, re-setting the seal after disassembling the high-speed restriction screw seal and readjusting it.
- The connection pin of the adjusting gear rod and tie rod fails
Exclusion Method: Overhauling
- The tie rod screw comes off
Removal Method: Reinstalling or replacing
- Connection pin of the tie rod loosens
Exclusion Method: Reinstalling or replacing
- Speed control spring breakage
Removal Method: Reassembling or replacing
- Broken speed control spring
Exclusion Method: Reassembling or replacing
- The connection pin of the adjusting gear rod and tie rod comes off
Removal method: Repair.
How to adjust the generator governor?
The generator governor primarily adjusts the closing voltage and regulation value.
- The adjustment of the closing voltage.
Using a 12V battery along with an ammeter in series, connect the battery terminals to the governor. Start the generator accessories and increase the speed gradually. Observe the ammeter pointer as the interceptor contact closure occurs. If the ammeter pointer swings towards the ‘+’ direction, the closure voltage is highly set and requires the reel spring tension to be reduced. If the ammeter pointer swings towards the ‘-‘ direction, the closure voltage is low, and the spring tension requires an increase. Continuously adjust until the interceptor contact closure occurs, and the ammeter pointer is almost stable. This indicates that the closure voltage is adjusted appropriately.
- Adjustment of the generator governor voltage value.
Use two dry cell batteries and batteries, ammeter in series, and connect the battery terminals in the governor. Start the engine and gradually increase the speed. When the regulator starts working, observe the ammeter pointer. If the ammeter pointer swings towards the ‘+’ direction, the regulator value is high, and the spring tension requires a reduction; if the ammeter pointer swings towards the ‘-‘ direction, the regulator value is low, and the spring tension requires an increase. Continuously adjust until the regulator starts working, and the ammeter pointer is almost stable. This indicates that the regulator value is correctly adjusted.
The principle of adjusting the generator regulator:
When the dry cell and battery are connected in series, there is a certain potential. When the generator produces a specific voltage, a current is generated whenever both are unequal. If the former potential is higher than the latter, the ammeter pointer swings towards the ‘-‘ direction, and if vice versa, to the ‘+’ direction. The ammeter pointer only remains stable when both potentials are almost equivalent.
Why does the governor affect the parallel operation of the generator? How to deal with it?
During the merging process, the generator governor has no impact on the connection work, whereas it can affect the system load distribution after the merger. Generators that exhibit harder characteristics require more load and may overload while the softer unit does not reach the rated load. The solution is to adjust the regulators of each generator set’s original engines, making their characteristics as similar as possible to ensure a more balanced and stable system load distribution.