Diesel generator frequency is too high, what is the impact?

The effect of high frequency on the generator: the frequency should not exceed 52.5HZ, which is 5% of the rated value. The increase in frequency is mainly limited by the strength of the rotating mechanical, the frequency is high, the rotational speed of the motor is high, and the rotational speed is high, and the centrifugal force on the rotor is increased, which easily damages some components of the rotor. The effect of low frequency on the generator: (1) The decrease of the frequency causes the rotation speed of the rotor to decrease, so that the air volume that is blown into the fan at both ends is reduced, the cooling condition of the generator is deteriorated, and the temperature of each part is increased. (2) The frequency is low, causing the temperature of the rotor coil to increase, otherwise the output will be reduced. (3) Low frequency may also cause the turbine to break the blade. (4) When the frequency is reduced, in order to keep the terminal voltage constant, it is necessary to increase the magnetic flux, which makes it easy to saturate the stator core, and the magnetic flux escapes, causing local high temperature and some parts of the structural components of the frame. Even taking Mars. (5) When the frequency is low, the speed of the motor for the factory is reduced, resulting in a decrease in output, which also has a negative impact on the safety of the user's electricity, product quality, and efficiency. (6) The frequency is low and the voltage is low. This is because the magnitude of the induced potential is related to the rotational speed. At the same time, the low speed of the generator also reduces the output of the coaxial exciter, affecting the reactive output. 16. What should the operator pay attention to when the generator is entering the phase? A: In theory, the generator can enter the phase, the so-called phase, that is, the power factor is ahead, the current of the generator is ahead of the terminal voltage. At this time, the generator still sends the active power to the system, but absorbs the reactive power. Power, excitation current is small, the generator is running under low excitation condition, we must pay attention to two problems when the generator enters phase operation: (1) static stability is reduced; (2) end leakage temperature causes stator end temperature Raise. 17. Say the principle, advantages and disadvantages of the 600MW generator brushless excitation system? Answer: The high-frequency 400HZ power supply generated by the permanent magnet machine stator is supplied to the main exciter excitation winding through two sets of full-controlled rectifier bridges. The intermediate frequency 200HZ power supply of the main excitation electromechanical armature is supplied to the rotary rectifier, and the DC output of the rectifier constitutes the excitation power of the generator. The conductive rod is fed to the field winding of the generator through the central bore of the rotor. Advantages of the generator brushless excitation system: (1) The large current collector ring and carbon brush device are eliminated to prevent the spark on the conventional commutator. (2) Compact structure. (3) Reduce the amount of operation and maintenance. Disadvantages of generator brushless excitation system: This excitation control system includes the time lag of the exciter. In order to improve its rapidity, the hard and negative feedback of the generator rotor voltage is added to the excitation regulator circuit, reducing the time constant. , but increased the exciter capacity and voltage value.