High Voltage Safety Marine Synchronous Generator W. Maes Department of Marine Engineering Antwerp Maritime Academy HV, 2016 Willem Maes High Voltage Safety
6.6KV Marine Synchronous Generator Willem Maes High Voltage Safety
Principle of operation Willem Maes High Voltage Safety
Number of poles f = p . n 120 f = frequency p = number of poles on the rotor n = speed of the generator Willem Maes High Voltage Safety
Stator Willem Maes High Voltage Safety
Main features of the Stator The winding is always connected in wye. The phase voltage is only 58% of the line voltage. Line to neutral 3th harmonics cancel each other out in star but add up in delta. Willem Maes High Voltage Safety
Main features of the Stator Willem Maes High Voltage Safety
Salient Pole Rotor Willem Maes High Voltage Safety
Main features of the Rotor Salient pole rotors 1 Salient poles are mounted on a steel frame. The Damper winding is a squirrel cage winding for smoothing sudden load changes. Cylindrical rotors 2 High speed generators 2 to for poles. Long solid steel cylinder with slots milled out to accommodate the windings. Willem Maes High Voltage Safety
Field Excitation and Exciters Figure : brushed excitation Willem Maes High Voltage Safety
Field Excitation and Exciters Figure : brushless excitation Willem Maes High Voltage Safety
No Load Saturation Curve Willem Maes High Voltage Safety
No Load Saturation Curve Willem Maes High Voltage Safety
Synchronous reactance and equivalent circuit of an AC generator Willem Maes High Voltage Safety
Synchronous reactance and equivalent circuit of an AC generator Willem Maes High Voltage Safety
Synchronous reactance and equivalent circuit of an AC generator Xs = 2 .π. f . L Xs = synchronous reactance per phase (Ω) f = generator frequency (Hz) L = apparent induction of the stator winding, per phase (H) Willem Maes High Voltage Safety
Equivalent circuit of a generator showing one phase Willem Maes High Voltage Safety
Synchronous Generator under Load Willem Maes High Voltage Safety
Type of Loads Isolated loads (single generator). The infinite bus. Willem Maes High Voltage Safety
Isolated Load lagging power factor Willem Maes High Voltage Safety
Isolated Load lagging power factor I x creates the flux Φ . Voltage E 0 is generated by flux Φ . Current I lags behind terminal voltage E by an angle ϕ . cos ϕ is the power factor of the load Voltage E x across the synchronous reactance leads current I bij 90deg E 0 equals the phasor sum of E and E x Both E 0 and Ex are voltages that exist inside the stator windings and cannot be measured directly. Willem Maes High Voltage Safety
Isolated Load leading power factor Willem Maes High Voltage Safety
Synchronization of a generator Willem Maes High Voltage Safety
Synchronization of a generator A generator is said to be synchronized when it meets the following conditions: The generator frequency is equal to the system frequency. The generator voltage is equal to the system voltage. The generator voltage is in phase with the system voltage. The phase sequence of the generator is the same as that of the system. Willem Maes High Voltage Safety
Synchronization of a generator Willem Maes High Voltage Safety
Synchronization of a generator Willem Maes High Voltage Safety
Synchronization of a generator Willem Maes High Voltage Safety
Synchronization of a generator Willem Maes High Voltage Safety
Synchronous generator on the Infinite Bus An infinite bus is so powerful it imposes its own Voltage and Frequency upon all apparatus connected to its terminals. On our machine we can only change: The exciting current I x . 1 The mechanical torque exerted by the driving engine. 2 Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Exciting Current Figure : Generator floating on an infinite bus Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Exciting Current Figure : Generator floating on an infinite bus Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Exciting Current Figure : Over Excited generator on infinite bus Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Exciting Current Figure : Over Excited generator on infinite bus Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Exciting Current Figure : Under Excited generator on infinite bus Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Exciting Current Figure : Under Excited generator on infinite bus Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Exciting Current If we over excite a synchronous generator connected to the infinite bus we will deliver reactive power to the bus. If we under excite a synchronous generator to the infinite bus we will draw reactive power from the bus. If our generator floats on the infinite bus we deliver or draw nothing. Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Mechanical Torque Figure : Varying mechanical torque Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Mechanical Torque Figure : phasor diagram varying torque Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Mechanical Torque Figure : Physical interpretation of alternator behavior Willem Maes High Voltage Safety
Infinite Bus, effect of varying the Mechanical Torque Figure : The N poles of the rotor are ahead of the S poles of the stator Willem Maes High Voltage Safety
Speeddroop Figure : Speeddroop of the engines regulator enables equal active load sharing Willem Maes High Voltage Safety
Speeddroop Figure : Voltage droop of the alternators AVR enables equal reactive load sharing Willem Maes High Voltage Safety
AVR Automatic Voltage Regulator Figure : Automatic Voltage Regulator Willem Maes High Voltage Safety
AVR Automatic Voltage Regulator Is a device that continuously monitors the voltage at the voltage regulating point of the system and maintains the terminal voltage of the generator. The AVR also controls that the synchronous generator operates within preset limits. An auxiliary winding supplies the excitation power under the control of the AVR. Willem Maes High Voltage Safety
AVR Automatic Voltage Regulator Is a device that continuously monitors the voltage at the voltage regulating point of the system and maintains the terminal voltage of the generator. The AVR also controls that the synchronous generator operates within preset limits. An auxiliary winding supplies the excitation power under the control of the AVR. Willem Maes High Voltage Safety
AVR Automatic Voltage Regulator Is a device that continuously monitors the voltage at the voltage regulating point of the system and maintains the terminal voltage of the generator. The AVR also controls that the synchronous generator operates within preset limits. An auxiliary winding supplies the excitation power under the control of the AVR. Willem Maes High Voltage Safety
AVR Automatic Voltage Regulator A voltage feedback is supplied by the voltage transformer and a current feedback is provided by the current transformer. The transformers are installed in the generator. Operational limits, such as over and under excitation, machine voltage and Volts/Hz, are implemented in the AVR. Static reactive power compensation in parallel operation and several other software functions are also available. Willem Maes High Voltage Safety
AVR Automatic Voltage Regulator A voltage feedback is supplied by the voltage transformer and a current feedback is provided by the current transformer. The transformers are installed in the generator. Operational limits, such as over and under excitation, machine voltage and Volts/Hz, are implemented in the AVR. Static reactive power compensation in parallel operation and several other software functions are also available. Willem Maes High Voltage Safety
AVR Automatic Voltage Regulator A voltage feedback is supplied by the voltage transformer and a current feedback is provided by the current transformer. The transformers are installed in the generator. Operational limits, such as over and under excitation, machine voltage and Volts/Hz, are implemented in the AVR. Static reactive power compensation in parallel operation and several other software functions are also available. Willem Maes High Voltage Safety
AVR Automatic Voltage Regulator A voltage feedback is supplied by the voltage transformer and a current feedback is provided by the current transformer. The transformers are installed in the generator. Operational limits, such as over and under excitation, machine voltage and Volts/Hz, are implemented in the AVR. Static reactive power compensation in parallel operation and several other software functions are also available. Willem Maes High Voltage Safety
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