What is the working principle of Marine electromechanical systems

Marine generator sets are generally placed in quasi-synchronous parallel. Assuming it is quasi-periodic, in addition to the same phase sequence, it should also meet the requirement that the two generators have the same frequency and voltage, and the phase difference is fundamentally the same, so that it can be connected to the power grid. Before being expelled, the load capacity should be reduced. When the sum of the powers of the two engines is less than or equal to the power of one generator, the circuit breaker of one of the engines can be disconnected. Attention should be paid to adjusting the frequency and voltage of the generator in operation to meet the requirements.

Marine generator sets, as backup power sources, are increasingly commonly used on ships. Due to their performance advantages, they have become an important component of the propulsion systems for ships weighing several thousand tons or more, especially military vessels. There are usually more than three generator sets, with two for daily use and one as a backup. It is necessary to combine the two generators for operation. The AC generator must meet four conditions: the phase sequence of the generators operating in parallel must be the same; Generators operating in parallel need to have the same voltage. Generators operating in parallel need to have the same frequency. The generators of four parallel trains must have the same phase Angle. Suppose there is a control box around the generator. Press the start generator button on the distribution board, and the generator side box will receive the signal to control the corresponding start equipment to start the generator. The first wiring was qualified. The second and third operations were carried out in parallel. Adjust the excitation of the generator to make the voltage equal; Adjust the rotational speed of the prime mover to make the frequency the same; Fourth, it is difficult to have the same phase Angle. On ships, the coarse synchronous parallel operation mode is usually adopted, that is, the shunt reactor is connected between the parallel generators. After meeting the above conditions, when the synchronous indicator approaches zero and the parallel switch is closed, the two generators are connected together through the shunt reactor. At this moment, under the constraint of the reactor, the circulating current between the two generators is within the allowable range, and this current will synchronize the two generators.