Interturn Short Circuit Protection of Synchronous Diesel Generator Set

Do you know what to do with the inter turn short circuit protection of synchronous diesel generator sets? As the longitudinal differential protection does not reflect the inter turn short circuit of the generator set stator winding, if the fault cannot be handled in a timely manner, it may develop into inter phase fault, causing serious damage to the diesel generator set. Therefore, inter turn short circuit protection should be installed on diesel generator sets (especially large diesel generator sets). The characteristic of turn to turn short circuit is that when one phase to turn short circuit occurs in the stator winding of a diesel generator set, there are positive sequence, negative sequence, and zero sequence components in the short circuit current, and each sequence current is equal. At the same time, non periodic components also appear at the beginning of the short circuit.

When there is a short circuit between different phase turns in a diesel generator set, there will inevitably be a circulating short circuit current. When the inter turn short circuit occurs in the stator winding of a diesel generator set, it disrupts the electromotive force balance between the three relative neutral points A, B, and C of the diesel generator set. When the zero sequence component of the three-phase unbalanced electromotive force is reflected in the voltage transformer, there is 3Uo at the output end of the open delta winding, and the zero sequence current generated in the primary circuit will form a circulating current between the two midpoints of the parallel branch winding.

Due to the occurrence of a negative sequence component during a phase to turn short circuit, it generates a reverse rotating magnetic field, which induces a current of twice the frequency in the rotor circuit. The current in the rotor, in turn, induces other harmonic components in the stator. This repeatedly affects each other between the stator and rotor, resulting in a series of harmonic components in the stator and rotor circuit. Moreover, due to the short circuiting of a portion of the coils in one phase, it may cause asymmetric armature reactions at different polarities, and generate harmonic components in the rotor circuit. The direction of the negative sequence power during inter turn short circuits in one phase is opposite to that during other internal and external asymmetric short circuits in the generator set.

Jiangsu Dingbo Power Generation Equipment Co., Ltd. was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. The company has a registered capital of 218.88 million yuan. The company covers an area of 86,000 square meters and a building area of 55,000 square meters. There are more than 660 employees, including 456 professional technicians and 106 senior technicians. It has 46 sales and service outlets nationwide. The main products are diesel engines, generator sets, and diesel generators, providing users with a one-stop service of design, supply, debugging and maintenance at any time. Dingbo has always insisted on using first-class talents, building first-class enterprises, manufacturing first-class products, creating first-class services, and making every effort to build a first-class domestic enterprise. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to sales@dieselgeneratortech.com.