Overview of automatic control system for diesel generators (ii)

1. Main functions of the automatic control system of diesel generator sets

According to China's GB/T12786 -- 1991 general technical conditions for automatic diesel generator sets, the general conditions mainly include the following eight aspects:

(1) maintain the ready running state automatically.

(2) automatic starting and loading.

(3) automatic stop.

(4) automatic juxtaposition and sorting.

(5) automatic supply.

(6) no one is on duty for time.

(7) automatic protection.

(8) other.

2. Classification of automatic control system of diesel generators

The designer or user of the automatic control system of diesel generator sets shall, from the actual situation, determine the necessary automatic control functions of the diesel generator sets according to the specific requirements. The rated power in our country is not more than 3200 kw stationary automation diesel generator set a 1996 GB/T4712 standard for automatic diesel generating set classification requirements and diesel generating sets according to the degree of automation can be divided into three:

(1) the performance of the first-class automatic diesel generator set is as follows:

1) single generating set automation for emergency power supply. Keep the voltage and frequency constant during cloud travel.

2) the generating set shall automatically maintain the emergency readiness operation (automatic charging of batteries; The cylinder is automatically inflated), and the diesel engine is automatically pre-lubricated before starting.

3) when the generator set needs to start, run or stop, it can start, run or stop automatically according to the automatic control instruction or remote control instruction.

4) during the operation of the generating set, if there are abnormal situations such as overload, short circuit, overspeed, overfrequency, high water temperature, low oil pressure, etc., automatic protection can be carried out.

5) the generating set shall be equipped with a sound and light signal system indicating normal operation and abnormal operation, and the operation condition of the unit shall be indicated by these indicators and alarm signals.

6) the generator unit should be able to run continuously for 4 hours without being on duty.


(2) in addition to meeting the requirements of the first-level automatic diesel generator set, the second-level automatic diesel generator set should also have the following functions:

1) the generating set shall have the function of automatic replenishment of fuel oil, oil and cooling water.

2) the generating unit can run continuously for 240h without being on duty.

(3) in addition to meeting the requirements of the first and second automation units, the third-level automatic diesel generating units must also have the following functions:

1) when the self-starting failure of the generating set fails, the self-starting control program system should be able to automatically transfer the starting instruction to another standby unit.

2) the generating set shall be able to automatically coordinate and reconcile two generators of the same type according to the automatic control instruction or remote control instruction.

3) the active power and reactive power output should be distributed automatically when the generating set is running in parallel.

4) in addition to the protection of primary and secondary automatic units, the generating units should also have the function of reverse power protection.

Three three-level automatic generating units can form an automatic power station. Two of them are commonly used as power supply units, and one is used as standby. The automatic control system shall automatically start and stop three generating units in sequence according to the load and operation conditions, parallel, unmarshalling and load distribution. The fault is divided into two stages: the first stage is a light fault, and the power supply should be uninterrupted, that is, the standby generating set should be put into parallel operation, and then the faulty generating set should be stopped. The second stage is a major fault. When the power generating unit with fault is stopped in an emergency, it is immediately put into the standby power generating unit, and the power supply is allowed to be interrupted for the secondary load.

3. Control panel of diesel generator set

The control panel of diesel generator set is divided into the control panel of ordinary generator set and the control panel of automatic generator set. The ordinary control panel is applicable to the control of ordinary diesel generator set. The starting and stopping of the generator set, the power supply and the power off, and the state adjustment are all operated by hand. The control panel of the automatic generating set is applicable to the control of the automatic diesel generating set, the starting and stopping of the generating set, the power supply and the power off. State adjustment can be done manually or automatically.

According to the installation method, the control panel of diesel generator unit can be divided into one unit type and one unit type. Split control panel means that the generator set is placed separately from the control panel, and the control system and main switch are installed in the control panel. One-piece control panel consists of two parts, control panel and switch panel, control panel (install) control system through damping pad is fixed on the top of the generator set, installed (main switch) switch panel on the side of the generator set.

(1) the average unit control panel by circuit breaker, ammeter, voltmeter, frequency table, water thermometer, the oil pressure gauge, the oil temperature table, tachometer, timer, and current transformer and so on, can complete the generator set start and stop, power supply and power control function, and running state of generator set for measurement, display, overrun alarm and protection.

(2) automatic generator control panel by automatic controller, auto heater, auto charger, automatic switching device, charging circuit breaker, ammeter, voltmeter, ammeter, voltmeter, dc voltage frequency table, water temperature table, oil pressure gauge, the oil temperature table, diesel engine tachometer, timer, alarm buzzer, relay control, protection switch, current transformer and so on. Automatic generator control panel can be done automatically on start and stop of units, power supply and power control function, and the running state of the unit measurement, display, overrun alarm and protection.