Sistemas de Generadores de Excitación

Sistema de Excitación – Magnetisísmo Residual Estator de Excitación Cojinete Eje Rectificador Rotor & Estator de Excitación Estator Principal Abanico Rotor Principal NO ANIMATION REQUIRED FIRST LETS LOOK AT THE EXCITER STATOR El magnetismo residual es requerido para dar energía al generador auto- excitado en el arranque inicial.

Sistema de Excitación - Estator Enrollado de Excitación X+ (F1) XX- (F2) Para A.V.R Terminales CONEXION ESPIRAL N S Núcleo de acero de alta-remanencia Reserva de Magnetismo Residual CLICK TO ANIMATE BULLETS ONLY THE EXCITER STATOR IS THE DC MAGNETIC FIELD FOR THE EXCITER GENERATOR THE D.C SUPPLY IS FROM THE OUTPUT OF THE AVR, AND IS CONTROLLED BY THE AVR CONTROL SYSTEM. WITH 12 OR 14 POLES, THE OUTPUT FREQUENCY OF THE EXCITER ROTOR IS 3 TO 3. 5 TIMES HIGHER THAN THE MAIN STATOR (50 TO 60 HZ). THE EXCITER STATOR IRON CORE ALSO STORES MAGNETISM, WHICH IS USED FOR INITIAL VOLTAGE BUILD UP. THIS IS KNOWN AS THE ‘RESIDUAL MAGNETISM’. GENERADOR PERMANENTE DE IMAN propulsado por los sistemas AVR, no requiere el magnetismo residual para la acumulación de voltaje inicial.

Sistema de Excitación - Generador Auto-Excitado Salida de C.D. de A.V.R en el Estator de Excitación REGULADOR AUTOMATICO DE VOLTAJE (A.V.R) Poder C.A. y Censor (retroalimentación) Desde el Estator Principal X+ (F1) XX- (F2) Cojinete Eje Rectificador Rotor y Estator de Excitación Estator Principal Abanico Rotor Principal System Operation on Engine Start- Up (self excited INITIAL EXCITATION IS PRODUCED BY RESIDUAL MAGNETISM IN THE EXCITER STATOR CORE. THE RESIDUAL VOLTAGE IS FED BACK FROM THE MAIN STATOR, TO THE A.V.R, AS A POWER SUPPLY. THE AVR FEEDS THIS POWER INTO THE EXCITER FIELD, WHICH FURTHER AMPLIFIES THIS POWER, WHICH IS FED INTO THE MAIN RECTIFIER ON THE SHAFT.THE RECTIFIER CONVERTS THIS 3 PHASE A.C INTO D.C (THE MAGNETIC FIELD). AN A.C POWER SUPPLY FOR THE AVR IS FED BACK FROM THE MAIN STATOR WINDINGS. A FEEDBACK SIGNAL (SENSING SUPPLY ), IS ALSO FED BACK FROM THE MAIN STATOR TO THE A.V.R, FOR CONTROL OF THE GENERATOR VOLTAGE. WHEN LOAD CURRENT IS SWITCHED ON, THE FEEDBACK SIGNAL WILL FALL. THE AVR MUST AUTOMATICALLY INCREASE ITS OUTPUT D.C TO RETURN THE VOLTAGE TO THE PRE-SET LEVEL, WHICH IT WILL THEN STABILISE IN APPROX. 1/3RD OF A SECOND. WHEN LOAD CURRENT IS RELEASED , THE OUTPUT VOLTAGE WILL RISE. THE AVR MUST AUTOMATICALLY RESPOND BY DECREASING THE EXCITATION VOLTAGE. ¿POR QUE NECESITAMOS UN GENERADOR DE EXCITACION?

ROTOR PRINCIPAL / ESTATOR Cambio magnético continuo Sistema de Excitación – Generador Sin Roce SALIDAS DEL GENERADOR RECTIFICADOR C.D. 3PH ROTOR PRINCIPAL ESTATOR PRINCIPAL C.A. REGULADOR AUTOMATICO DE VOLTAJE (AVR) Eje F1+ F2- + _ U V W N ROTOR PRINCIPAL / ESTATOR BRECHA AEREA BRECHA AEREA DE EXCITACION Cambio magnético continuo Con generadores sin roce, la energía eléctrica es traspasada por el cambio continuo magnético de los componentes estacionarios a los componentes girando, al otro lado de las brechas aéreas. ¿QUE HARIA UN SISTEMA ALTERNATIVA AL DISEÑO SIN ROCE?

Alternativa Sin Roce – Desliz y Roce SISTEMA DE CONTROL Poder C.A. y Censor (retroalimentación) Desde el Estator Principal CORRIENTE DE EXCITACION C.D. Cojinete Eje Estator Principal Abanico Rotor Principal ROCE DE CARBON System Operation on Engine Start- Up (self excited INITIAL EXCITATION IS PRODUCED BY RESIDUAL MAGNETISM IN THE EXCITER STATOR CORE. THE RESIDUAL VOLTAGE IS FED BACK FROM THE MAIN STATOR, TO THE A.V.R, AS A POWER SUPPLY. THE AVR FEEDS THIS POWER INTO THE EXCITER FIELD, WHICH FURTHER AMPLIFIES THIS POWER, WHICH IS FED INTO THE MAIN RECTIFIER ON THE SHAFT.THE RECTIFIER CONVERTS THIS 3 PHASE A.C INTO D.C (THE MAGNETIC FIELD). AN A.C POWER SUPPLY FOR THE AVR IS FED BACK FROM THE MAIN STATOR WINDINGS. A FEEDBACK SIGNAL (SENSING SUPPLY ), IS ALSO FED BACK FROM THE MAIN STATOR TO THE A.V.R, FOR CONTROL OF THE GENERATOR VOLTAGE. WHEN LOAD CURRENT IS SWITCHED ON, THE FEEDBACK SIGNAL WILL FALL. THE AVR MUST AUTOMATICALLY INCREASE ITS OUTPUT D.C TO RETURN THE VOLTAGE TO THE PRE-SET LEVEL, WHICH IT WILL THEN STABILISE IN APPROX. 1/3RD OF A SECOND. WHEN LOAD CURRENT IS RELEASED , THE OUTPUT VOLTAGE WILL RISE. THE AVR MUST AUTOMATICALLY RESPOND BY DECREASING THE EXCITATION VOLTAGE. DESLIZ LA CORRIENTE DEL ROTOR PRINCIPAL ES PROPORCIONADA POR VIA DEL DESLICE Y DEL ROCE.

Sistema de Excitación – Factores de Amplificación Salida de C.D. de A.V.R en el Estator de Excitación REGULADOR AUTOMATICO DE VOLTAJE (A.V.R) Poder C.A. y Censor (retroalimentación) Desde el Estator Principal X+ (F1) XX- (F2) Cojinete Eje Rectificador Rotor y Estator de Excitación Estator Principal Abanico Rotor Principal System Operation on Engine Start- Up (self excited INITIAL EXCITATION IS PRODUCED BY RESIDUAL MAGNETISM IN THE EXCITER STATOR CORE. THE RESIDUAL VOLTAGE IS FED BACK FROM THE MAIN STATOR, TO THE A.V.R, AS A POWER SUPPLY. THE AVR FEEDS THIS POWER INTO THE EXCITER FIELD, WHICH FURTHER AMPLIFIES THIS POWER, WHICH IS FED INTO THE MAIN RECTIFIER ON THE SHAFT.THE RECTIFIER CONVERTS THIS 3 PHASE A.C INTO D.C (THE MAGNETIC FIELD). AN A.C POWER SUPPLY FOR THE AVR IS FED BACK FROM THE MAIN STATOR WINDINGS. A FEEDBACK SIGNAL (SENSING SUPPLY ), IS ALSO FED BACK FROM THE MAIN STATOR TO THE A.V.R, FOR CONTROL OF THE GENERATOR VOLTAGE. WHEN LOAD CURRENT IS SWITCHED ON, THE FEEDBACK SIGNAL WILL FALL. THE AVR MUST AUTOMATICALLY INCREASE ITS OUTPUT D.C TO RETURN THE VOLTAGE TO THE PRE-SET LEVEL, WHICH IT WILL THEN STABILISE IN APPROX. 1/3RD OF A SECOND. WHEN LOAD CURRENT IS RELEASED , THE OUTPUT VOLTAGE WILL RISE. THE AVR MUST AUTOMATICALLY RESPOND BY DECREASING THE EXCITATION VOLTAGE. ¿COMO CONTROLA EL VOLTAJE DEL GENERADOR EL AVR?

+ _ Sistema de Excitación – Factores de Amplificación Salida del AVR C.D. 56 VDC @ Carga Entera EJEMPLO :- TAMAÑO DE ARMADURA P7G, 2000 Kw. (2MW) RECTIFICADOR C.D. 3PH ROTOR PRINCIPAL ESTATOR PRINCIPAL C.A. REGULADOR AUTOMATICO DE VOLTAJE (AVR) Eje F1+ F2- + _ U V W N SALIDAS DEL GENERADOR 2,000,000 WATTS (2MW) Salida del AVR = 56V/16 ohmios = 3.5A PODER = 56V X 3.5A = 196 WATTS Estator de Excitación 16 ohmios Resistencia del Rotor = 2.42 Ohmios CORRIENTE DEL ROTOR = 64A C.D. Volts = IR = 155 VDC PODER = VI = 9920 Watts FACTORES DE AMPLIFICACION Salida del AVR a la entrada del ROTOR PRINCIPAL = 9920W/ 196W = 50.6 X Amplificación ROTOR PRINCIPAL a la salida del ESTATOR PRINCIPAL, = 2,000,0000W / 9920W = 201.6 X Amplificación FACTOR DE AMPLIFICACION TOTAL = 50.6 X 201.6 = 10,200 X Amplificación

Sistemas de Excitación – Generador Excitado Separadamente Generador de Imán Permanente (PMG) P2, P3, P4 Suministro Eléctrico al A.V.R Generador de Eje (Lado Sin Arranque) Polo Dowel para la ubicación del rotor del PMG Rotor de imán de cerámica con campo saturado muy magnético. Rotor de 8 Polos, 100 HZ (a 1500 RPM ) o 120 HZ (a 1800 RPM ) READ AS TEXT THE PMG IS ALSO AN EXTREEMLY POWERFUL GENERATOR AT LOW SPEEDS, AND THUS PROVIDES THE AVR WITH AN ALMOST IMMEDIATE POWER SUPPLY WHEN THE ENGINE IS STARTED. THE PMG POWERED AVR THEREFORE, DOES NOT DEPEND UPON RESIDUAL MAGNETISM IN THE EXCITER STATOR TO BEGIN THE VOLTAGE BUILD UP PROCESS, (ALTHOUGH RESIDUAL IS STILL THERE). IN FACT, THE PMG IS SO FAST THAT WE HAVE TO SLOW DOWN VOLTAGE BUILD UP, TO PREVENT OVERSHOOT OF VOLTAGE ON RUN UP. THIS IS CALLED ‘SOFT START’ VOLTAGE BUILD UP. HOWEVER, ALL GENERATORS HAVE RESIDUAL MAGNETISM STORED IN THE EXCITER FIELD. Por mueble empotrado de perno sin tracción al eje final Estator de Imán Permanente de 3 Fases C.A. 170 a 220 Voltios, suministro eléctrico separado para el A.V.R.

Sistema de Excitación – Generadores Excitados Separadamente P2 -P3 -P4 A.V.R PMG Suministro de Poder al A.V.R Suministro Detector C.A. Del Estator Principal (de 2 o 3 Fases) X+ (F1) 6-7-8 XX- (F2) Cojinete Eje Rectificador Rotor y Estator de Excitación Estator Principal Abanico Rotor Principal THE PMG SYSTEM IS IDENTICAL TO THE SELF EXCITED SYSTEM, WITH EXCEPTION OF THE AVR POWER SUPPLY, WHICH IS NOW INDEPENDANTLY PROVIDED BY THE PMG. THIS IS CALLED A ‘SEPARATELY EXCITED’ GENERATOR. ADVATAGES :- SEE NEXT SLIDE El generador de PMG provee un suministro eléctrico separado para el AVR.

Generadores Excitados Separados VENTAJAS PRINCIPALES DEL SISTEMA EXCITADO SEPARADO CORRIENTE DE CORTO CIRCUITO SOSTENIDO BAJO CONDICIONES DE FALLAS NO ES AFECTADO POR LA DISTORCION ONDULATORIA CAUSADA POR LAS CARGAS NO LINEARES SISTEMA DE ACUMULACION DE ALTO VOLTAJE EN EL ARRANQUE INICIAL CAPAZ DE ACUMULAR VOLTAJE CONTRA CARGA, (EN LA FRECUENCIA DE ARRANQUE DE LOS MOTORES GRANDES). SUMINISTRO DE PODER AISLADO PARA EL AVR, (PROTEGE EL AVR DE LAS CONDICIONES DE FALLA DE ALTA TRANSICION EN EL SISTEMA DE DISTRIBUCION) READ AS TEXT

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