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Figure 4 shows the control mechanism of the IGC. Initially the generated voltage is tapped from the line and this voltage is stepped down by transformer and applied to zero crossing detectors. Zero crossing detectors are used for positive half and negative half detection of the input sine wave and produce square waves. These square waves are converted to ramp signal by Ramp Converter. Rectifier (center tapped diode rectifier) rectifies the supply ac voltage to dc voltage. This dec voltage is subtracted by a reference voltage to get the error signal (voltage) using differential amplifier. The subtracted voltage is given to PI Controller. The ramp signal and the erro1 signal from PI Controller are compared by the comparator to give out the pulse signal to the gate of TRIAC for firing. The width of the pulse determines the firing angle of the TRIAC. Thus power to the ballast load is controlled by IGC.

Figure 4 shows the control mechanism of the IGC. Initially the generated voltage is tapped from the line and this voltage is stepped down by transformer and applied to zero crossing detectors. Zero crossing detectors are used for positive half and negative half detection of the input sine wave and produce square waves. These square waves are converted to ramp signal by Ramp Converter. Rectifier (center tapped diode rectifier) rectifies the supply ac voltage to dc voltage. This dec voltage is subtracted by a reference voltage to get the error signal (voltage) using differential amplifier. The subtracted voltage is given to PI Controller. The ramp signal and the erro1 signal from PI Controller are compared by the comparator to give out the pulse signal to the gate of TRIAC for firing. The width of the pulse determines the firing angle of the TRIAC. Thus power to the ballast load is controlled by IGC.

Related Figures (9)

Figure 1. C-2C Connection for SEIG The schematic diagram of a C-2C SEIG system is shown in Figure 1.
Figure 1. C-2C Connection for SEIG The schematic diagram of a C-2C SEIG system is shown in Figure 1.
Figure 2. No-load magnetization characteristic and capacitive impedance line
Figure 2. No-load magnetization characteristic and capacitive impedance line
Figure 4. Block Diagram of IGC
Figure 4. Block Diagram of IGC
Figure 3. Schematic diagram for Mini-grid connection The proposed system, under design consists of two generators producing different power outputs. For design purpose, two MG sets are used to produce required power output. These two generators were connected to a point of common coupling to form a Mini-grid. The amount of power required is sent to the Mini-grid and remaining power is dumped in the ballast load. This mechanism was controlled by two independent IGCs. The synchronization was required for the generators to be connected to the Mini-grid, and the synchronization was done by the synchronizer unit. This is performed in by self-excited induction generators which are coupled to DC motors working as prime mover for induction generators. The consumer loads are considered by using resistive filament bulbs. The power output of both generators is fed to the same main load connected through Mini-grid. In the experiment the SEIG | is taken as reference and SEIG 2 is synchronized to it. Fig 3 shows the schematic diagram of the proposed Mini-grid system.
Figure 3. Schematic diagram for Mini-grid connection The proposed system, under design consists of two generators producing different power outputs. For design purpose, two MG sets are used to produce required power output. These two generators were connected to a point of common coupling to form a Mini-grid. The amount of power required is sent to the Mini-grid and remaining power is dumped in the ballast load. This mechanism was controlled by two independent IGCs. The synchronization was required for the generators to be connected to the Mini-grid, and the synchronization was done by the synchronizer unit. This is performed in by self-excited induction generators which are coupled to DC motors working as prime mover for induction generators. The consumer loads are considered by using resistive filament bulbs. The power output of both generators is fed to the same main load connected through Mini-grid. In the experiment the SEIG | is taken as reference and SEIG 2 is synchronized to it. Fig 3 shows the schematic diagram of the proposed Mini-grid system.
Figure 7. Load current Vs Phase Voltage of Generator 1 The de motor working as prime mover is run at 1620 rpm. Then the corresponding phase voltage, phase current, and load current is noted at different load conditions with constant speed of 1620 rpm. The recorded voltages and currents are shown in fig 7 and 8.
Figure 7. Load current Vs Phase Voltage of Generator 1 The de motor working as prime mover is run at 1620 rpm. Then the corresponding phase voltage, phase current, and load current is noted at different load conditions with constant speed of 1620 rpm. The recorded voltages and currents are shown in fig 7 and 8.
This experiment is carried out for two sets of motors and generators. The experimental setup connections is shown in the figure 6
This experiment is carried out for two sets of motors and generators. The experimental setup connections is shown in the figure 6
Figure 9. Load current Vs Phase current of Generator 2 The similar experiment is performed for another set of SEIG. A separately excited dc motor rated at 190 V field voltages, 1500 rpm, 2.75 kW, is used as a prime mover for 3 phase squirrel cage induction motor of rating 50Hz, 1.1 kW, 400V, 2.5 A and 4 no. of poles. The value of capacitor for self excitation in this generator is found to be 11.12 uF between phase ‘a’ and phase ‘b’ and 18.32 uF is connected in between phase ‘b’ and phase ‘c’. The graph is plotted between three phase terminal voltages as shown in fig. 8.
Figure 9. Load current Vs Phase current of Generator 2 The similar experiment is performed for another set of SEIG. A separately excited dc motor rated at 190 V field voltages, 1500 rpm, 2.75 kW, is used as a prime mover for 3 phase squirrel cage induction motor of rating 50Hz, 1.1 kW, 400V, 2.5 A and 4 no. of poles. The value of capacitor for self excitation in this generator is found to be 11.12 uF between phase ‘a’ and phase ‘b’ and 18.32 uF is connected in between phase ‘b’ and phase ‘c’. The graph is plotted between three phase terminal voltages as shown in fig. 8.
Figure 6. Load current Vs Phase current of Generator | In the fig. 7 the graph is plotted between 3-phase terminal voltages Vay, Voc, and Va; and load current I, using the terminal capacitors in C-2C configuration with star connection of stator winding of induction generator. When the load is less or light, the terminal voltages Vy, Vic, and V., are not equal. The voltage V,, is less than other voltages because of parallel connection of 2C in that phase. When the load increases, the terminal voltages V4, Vpc, and V., converge to the operating voltage ie. 220 V. Similarly, in fig. 8 graph shows plot between 3-phase terminal currents I,, I,, and I,; and the load current I,. At fewer loads, the terminal currents are not equal and the current I, is less than others due the 2C in that phase. When the load increases the terminal currents converge to the operating current i.e. 1.5A of load current.
Figure 6. Load current Vs Phase current of Generator | In the fig. 7 the graph is plotted between 3-phase terminal voltages Vay, Voc, and Va; and load current I, using the terminal capacitors in C-2C configuration with star connection of stator winding of induction generator. When the load is less or light, the terminal voltages Vy, Vic, and V., are not equal. The voltage V,, is less than other voltages because of parallel connection of 2C in that phase. When the load increases, the terminal voltages V4, Vpc, and V., converge to the operating voltage ie. 220 V. Similarly, in fig. 8 graph shows plot between 3-phase terminal currents I,, I,, and I,; and the load current I,. At fewer loads, the terminal currents are not equal and the current I, is less than others due the 2C in that phase. When the load increases the terminal currents converge to the operating current i.e. 1.5A of load current.
Figurel0. Load current Vs Phase Voltage of Generator 2
Figurel0. Load current Vs Phase Voltage of Generator 2
Related topics:
EngineeringRural ElectrificationInduction MotorInduction GeneratorGrid SystemGrid Connection
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