Skip to main content

What Are the Causes of Sudden Short Circuit of Diesel Generator Set


Because magnetic circuit and magnetic resistance for direct axis of synchronous generator is different from that of variable axis, the stator and rotor are in relative motion, so the mutual inductance coefficient and self-inductance coefficient of stator and rotor are not constant. It is difficult to analyze and solve by using differential equations, based on the principle of flux conservation in superconducting closed loop, explain from the physical concept, and derives the short circuit current in each winding when sudden short circuit occurs.

Characteristics of sudden short circuit for diesel generators

1.In the case of steady-state short-circuit, the steady-state short-circuit current is not large because of the large synchronous reactance, while in the case of sudden short-circuit, the sudden short-circuit current is large because the super-transient reactance limiting its current is very small and contains DC component. The peak value of the sudden short-circuit current can reach more than ten times of the rated current.

2.With the emergence of this impulse current, the winding of the electric motor will be affected by a great impulse electromagnetic force, which may cause the winding to be deformed or even the insulation of the winding to be damaged.

3.In the process of sudden short-circuit, the electric motor is affected by strong short-circuit torque, which can cause vibration.

4. Overvoltage occurs in stator and rotor windings of motors.



Characteristics of physical phenomena in generators during sudden short circuit

1.When in steady-state short circuit, the armature current is constant, and the corresponding armature magnetic potential is a constant amplitude rotating magnetic field rotating at synchronous speed, therefore, it will not induce electromotive force and generate current in the rotor winding. From the current relationship, it is equivalent to the open circuit state of transformer.

2.When short circuit occurs suddenly, the magnitude of armature current varies, and the corresponding magnitude of armature magnetic field varies. Therefore, the transformer between stator and rotor can induce potential and current in the rotor winding, and then affect the change of current in the stator winding. From the point of view of electromagnetic relationship, it is equivalent to the sudden short-circuit state of transformer.
标签：

Comments

Post a Comment

Popular posts from this blog

What Is the Difference Between Electric Motor and Electric Generator

An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and winding currents to generate force. In certain applications, such as in regenerative braking with traction motors, electric motors can be used in reverse as generators to recover energy that might otherwise be lost as heat and friction. An electric generator operates in the reverse direction, converting mechanical energy into electrical energy. Electric generator can be divided into various type, open type, silent type, trailer type, portable type and container type, etc. Electric generator is mainly composed of diesel engine & alternator. Electric generator set is mainly composed of engine, alternator, control module, and common base. Electric generator :- Electric generator is a type of machine which converts mechanical input (energy) into electrical output (
1 comment
Read more

Engine Fault Code Messages - Volvo Penta Engine

Volvo Penta Engine Fault Code When a malfunction has occurred and the diagnostic system has generated one or more fault codes, these are read out differently depending on the equipment used. Please refer to “Fault code messages”. If the system indicates that a fault code has been set: 1 Cut engine speed to idle, or shut the Volvo engine off. 2 For DCU/DU Read the fault code from the display, please refer to Reading fault codes via the DCU or Reading fault codes via the DU. For CIU press the diagnostic button and read the fault code, by observing the flashing of the diagnostic lamp. Refer to Reading fault codes via the diagnostic lamp, CIU. 3 Look up the fault code in the Fault Code Register chapter and take the recommended measures. Reading fault codes via the DU (Display Unit) Depending on the severity of the fault the text, either WARNING! or ALARM STOP (a buzzer sounds) will be shown on the display 1 Press any button to come to the fault list. The f
Post a Comment
Read more

Types of Diesel Engine and Application of Diesel Generator

This article will guide you to learn diesel engine types and important role of diesel generator. If you are interested, please keep reading.  What Are Diesel Engines? A type of internal combustion engine more accurately known as a compression ignition engine is designed to provide power by compressing the fuel at high temperature and significant pressure until it ignites. Diesel engines are either two-stroke or four-stroke .   ‘Stroke’ means the movement of the piston in the engine. Two-stroke This engine uses one stroke in each direction.   The first stroke being compression, which results in the ignition of the compressed fuel.   The return stroke brings new fuel into the cylinder. Four-stroke This engine has one compression stroke and one exhaust stroke and each one of those has a return stroke – hence, four-stroke. The compression stroke compresses the fuel/air mixture prior to ignition.   The exhaust stroke pushes the burnt gases out the exhaust. The
Post a Comment
Read more