Analysis of Dongguan Generator Rental Generator Rotor Demagnetization and Overvoltage Protection

Analysis of Dongguan Generator Rental Generator Rotor Demagnetization and Overvoltage Protection

Dongguan generator rentalWhen the generator rotor is working normally, since the thyristor is not conducting and the diode is reversed, no current flows through it. When the forward overvoltage of the rotor is greater than the set value, scrv2 is triggered and an overvoltage pulse path is formed through the ZnO nonlinear resistor. , limiting the overvoltage at the rotor terminal 2. At the same time, based on the inherent characteristics of the ZnO non-linear resistor, the action of the reed current relay is triggered by the wiring, triggering scrk3. At this time, the overvoltage counter acts and the overvoltage indicator light lights up.

Dongguan generator rental generator rotor demagnetization and over-voltage protection When the over-voltage disappears, Tr1 automatically closes, the ZnO non-linear resistor shows high resistance, which is not enough to maintain the maintenance current of V2, scrv2 automatically closes and returns to normal working status. When fmk When suddenly disconnected, the rotor generates a reverse overvoltage. The reverse pressure forms a demagnetization channel through the diode V1 and the ZnO nonlinear resistor. The voltage limit of the rotor is limited by the ZnO nonlinear resistor. At the same time, the residual magnetic energy of the rotor is reduced. Absorption The nonlinear resistor eliminates the magnetic field and uses a reed current relay for relay protection. The device KA1 will move. The demagnetization counter PC2 works and the demagnetization signal light is on. 2 Demagnetization performance analysis The demagnetization energy of the ZnO nonlinear resistor RF should meet the excitation The energy Qmax stored in the system generator rotor under harsh conditions. When the excitation system is under no-load false strong excitation, the rotor current is 2260a and Qmax can be calculated. Therefore, if the demagnetization switch is turned off at this time, the energy absorbed by RF is: Then RF Absorbed energy (assuming that the energy consumed by the rotor itself and the energy absorbed by the demagnetization switch itself are not considered)

Dongguan Generator Rental When the radio frequency demagnetization energy of the generator is 1.5mi, the radio frequency demagnetization energy can fully meet the demagnetization of the generator under various working conditions. The expansion curve of the ZnO nonlinear resistor rotor overvoltage protection should be below The allowable withstand voltage level of the rotor excitation winding has a certain margin, which is generally lower than 70% of the allowable insulation voltage of the rotor winding; at the same time, the operating voltage should be higher than the normal excitation voltage. The main function of the zinc oxide nonlinear resistor is to identify and limit Instantaneous overvoltage, can be used repeatedly without damage. The voltage range is from a few volts to several thousand volts, the current range is from a few amperes to several thousand amperes, and the energy absorption capacity is from a few joules to several thousand joules.