Quasi synchronous juxtaposition is generally adopted for marine generator sets. Assuming quasi period, in addition to the same phase sequence, it should also meet the same frequency and voltage of two generators, and the phase difference is basically the same, which can be connected with the power grid. Before delisting, the load should be reduced. When the sum of the power of two generators is less than or equal to the power of one generator, the circuit breaker of one generator can be disconnected. Pay attention to adjusting the frequency and voltage of the generator in operation to meet the request.
As a backup power supply, marine generator set is more and more widely used in ships. Because of its performance advantages, it has become an important part of the propulsion system of ships with more than thousands of tons, especially military ships. There are generally more than three generator sets, two for daily use and one for standby, and it is necessary to merge and use the two generators; It is necessary to meet four conditions for communicating generators: the phase sequence of generators operating in parallel must be the same; It is necessary for generators running in parallel to have the same voltage; Generators running in parallel must 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 switchboard, and the generator side box will receive the signal to control the corresponding starting equipment to start the generator. The first wiring is qualified, and the second and third parallel operation. Adjust the generator excitation to make the voltage equal; Adjust the prime mover speed to make the frequency the same; Fourth, it is difficult to have the same phase angle. Rough synchronous parallel operation mode is usually adopted on board, that is, the shunt reactor is connected between the parallel generators. After the above conditions are met, when the synchronization indicator is close to zero and the parallel switch is closed, the two generators are connected together through the shunt reactor. At this moment, under the constraint of reactor, the circulating current between the two generators is within the allowable range, which will synchronize the two generators.