Generator Manufacturer Out-of-step Protection

Generator stator ground fault protection for generator stator single-phase ground fault protection, three times by some fundamental zero sequence voltage and harmonic voltage of two parts, the first harmonic zero sequence voltage protection machine tail end to 95% area of the stator winding single-phase grounding fault, the reflected power pattern in the zero sequence voltage principle, by the time t1 (3 s) list out the magnetic action in solution;  The third harmonic voltage protects the stator winding single-phase grounding fault from the tail to 30% of the end of the machine, which is composed of generator neutral point and the principle of the third harmonic of the end of the machine, and acts on the signal through time t2 (5s).  Both constitute 100% stator grounding protection.  The protection is equipped with PT wire break lock.  

Stator turn to turn protection of generator  

The protection is composed of longitudinal zero-sequence voltage and negative sequence direction criterion of fault classification. The PT disconnection blocking measure is set as the main protection of inter-turn, inter-phase short circuit and stator winding opening welding inside the generator.  The fault component negative sequence direction criterion realizes the longitudinal zero sequence voltage criterion realizes the longitudinal 3U0 output by the 3PT open triangle winding which is directly connected to the generator neutral but not grounded through detecting the negative sequence power of the generator.  Protection action stops at all.  

Generator manufacturer out-of-step protection  

The protection uses three impedance elements, through the impedance trajectory change to detect the number of slip pole and determine the location of the oscillation center.  In the case of short circuit fault, system oscillation, voltage circuit break, etc., protection against misoperation.  Guard general action on signal;  When the oscillation center is inside the generator and transformer group, the protection section I starts to send the tripping command through T1 (0.5s), and the action is to deactivate the magnetic field.  When the oscillation center is outside the generator-transformer set, the protection II section is initiated to signal through T2 (2S).  The protection is equipped with a current locking device to ensure that the current does not exceed the rated out-of-step breaking current of the circuit breaker when the circuit breaker is off.  

Low frequency accumulative protection  

Low frequency accumulation protective reaction system frequency to reduce the cumulative effect of the impact of the steam turbine, protection is composed of sensitive frequency relay and counter, locking the outlet circuit breaker auxiliary contacts (that is, the low frequency generator exit runtime accumulative protection also quit running), the cumulative system frequency is lower than 47.5 Hz frequency setting time, when the set values for the total time to 3000 seconds,  Signal will be sent after 30 seconds delay.  The device can be monitored in real time during operation: constant value, frequency F and accumulated time display.  Differential protection of generator and transformer group, differential protection of transformer and high differential protection are the main protection of interphase short circuit fault of protected components, using ratio brake principle.  The out-of-zone fault can reliably avoid the unbalanced current generated by the inconsistency of CT characteristics of each side, and the in-zone fault protection can act sensitively.  In order to avoid protection misoperation under transformer inrush current, the protection adopts second harmonic locking.  The protection is equipped with the function of blocking differential flow rate without second harmonic wave, and the fault can be removed instantly when the differential current reaches the setting value.  The protection has CT line break locking function (not actually used).  CT line break discrimination is the same as generator differential protection.  

Guangxi Dingbo Power Equipment Manufacturing Co., Ltd. established in 2006, is an manufacturer of diesel generator in China, which integrates design, supply, commissioning and maintenance of diesel generator set. Product covers Cummins, Perkins, Volvo, Yuchai, Shangchai, Deutz, Ricardo, MTU, Weichai etc. with power range 20kw-3000kw, and become their OEM factory and technology center.