SIMULACOES
Modelos utilizados na simulacao
1 -
The PV array consists of one string of 14 Trina Solar TSM-250 modules connected in series.
1 -
The PV array consists of one string of 14 Trina Solar TSM-250 modules connected in series.
At 25 deg. C and with a solar irradiance of 1000 W/m2, the string can produce 3500 W.
Two small capacitors, connected on the + and - terminals of the PV array, are used to model the parasitic capacitance between the PV modules and the ground.
The inverter is modeled using a PWM-controlled single-phase full-bridge IGBT module ( H-bridge). The topology of the grid-side filter is the classical LCL configuration with the inductors split equally between the line and the neutral branches.
The control system contains five major Simulink-based subsystems:
- MPPT Controller: The Maximum Power Point Tracking (MPPT) controller is based on the 'Perturb and Observe' technique. This MPPT system automatically varies the VDC reference signal of the inverter VDC regulator in order to obtain a DC voltage which will extract maximum power from the PV string.
- VDC Regulator: Determine the required Id (active current) reference for the current regulator.
- Current Regulator: Based on the current references Id and Iq (reactive current), the regulator determines the required reference voltages for the inverter. In our example, the Iq reference is set to zero.
- PLL & Measurements: Required for synchronization and voltage/current measurements.
- PWM Generator: Use the PWM bipolar modulation method to generate firing signals to the IGBTs. In our example, the PWM carrier frequency is set to 3780 Hz (63*60).
The grid is modeled using a typical pole-mounted transformer and an ideal AC source of 14.4 kVrms. The transformer 240V secondary winding is center-tapped and the central neutral wire is grounded via a small resistance Rg. The residential load (20 kW / 4 kvar @ 240 Vrms) is equally distributed between the two "hot" (120 V) terminals.
2 -
The PV array consists of 86 parallel strings. Each string has 7 SunPower SPR-415E modules connected in series.
The converter is modeled using a 3-level IGBT bridge PWM-controlled. The inverter choke RL and a small harmonics filter C are used to filter the harmonics generated by the IGBT bridge. A 250-kVA 250V/25kV three-phase transformer is used to connect the inverter to the utility distribution system.
The control system contains five major Simulink-based subsystems:
- MPPT Controller: The Maximum Power Point Tracking (MPPT) controller is based on the 'Perturb and Observe' technique. This MPPT system automatically varies the VDC reference signal of the inverter VDC regulator in order to obtain a DC voltage which will extract maximum power from the PV array.
- VDC Regulator: Determine the required Id (active current) reference for the current regulator.
- Current Regulator: Based on the current references Id and Iq (reactive current), the regulator determines the required reference voltages for the inverter. In our example, the Iq reference is set to zero.
- PLL & Measurements: Required for synchronization and voltage/current measurements.
- PWM Generator: Generate firing signals to the IGBTs based on the required reference voltages. In our example, the carrier frequency is set to 1980 Hz (33*60)..
The grid is modeled as a typical North American distribution grid. It included two 25-kV feeders, loads, grounding transformer and an equivalent 120-kV transmission system.
3 -
The PV farm consists of four PV arrays delivering each a maximum of 100 kW at 1000 W/m2 sun irradiance. A single PV array block consist of 64 parallel strings where each string has 5 SunPower SPR-315E modules connected in series.
Each PV array is connected to a DC/DC converter (average model). The outputs of the boost converters are connected to a common DC bus of 500 V. Each boost is controlled by individual Maximum Power Point Trackers (MPPT). The MPPTs use the "Perturb and Observe" technique to vary the voltage across the terminals of the PV array in order get the maximum possible power.
A three-phase Voltage Source Converter (VSC) converts the 500 V DC to 260 V AC and keeps unity power factor. A 400-kVA 260V/25kV three-phase coupling transformer is used to connect the converter to the grid. The grid model consists of typical 25-kV distribution feeders and 120-kV equivalent transmission system.
In the average model the boost and VSC converters are represented by equivalent voltage sources generating the AC voltage averaged over one cycle of the switching frequency. Such a model does not represent harmonics, but the dynamics resulting from control system and power system interaction is preserved.
The PV array consists of 86 parallel strings. Each string has 7 SunPower SPR-415E modules connected in series.
The converter is modeled using a 3-level IGBT bridge PWM-controlled. The inverter choke RL and a small harmonics filter C are used to filter the harmonics generated by the IGBT bridge. A 250-kVA 250V/25kV three-phase transformer is used to connect the inverter to the utility distribution system.
The control system contains five major Simulink-based subsystems:
- MPPT Controller: The Maximum Power Point Tracking (MPPT) controller is based on the 'Perturb and Observe' technique. This MPPT system automatically varies the VDC reference signal of the inverter VDC regulator in order to obtain a DC voltage which will extract maximum power from the PV array.
- VDC Regulator: Determine the required Id (active current) reference for the current regulator.
- Current Regulator: Based on the current references Id and Iq (reactive current), the regulator determines the required reference voltages for the inverter. In our example, the Iq reference is set to zero.
- PLL & Measurements: Required for synchronization and voltage/current measurements.
- PWM Generator: Generate firing signals to the IGBTs based on the required reference voltages. In our example, the carrier frequency is set to 1980 Hz (33*60)..
3 -
The PV farm consists of four PV arrays delivering each a maximum of 100 kW at 1000 W/m2 sun irradiance. A single PV array block consist of 64 parallel strings where each string has 5 SunPower SPR-315E modules connected in series.
Each PV array is connected to a DC/DC converter (average model). The outputs of the boost converters are connected to a common DC bus of 500 V. Each boost is controlled by individual Maximum Power Point Trackers (MPPT). The MPPTs use the "Perturb and Observe" technique to vary the voltage across the terminals of the PV array in order get the maximum possible power.
A three-phase Voltage Source Converter (VSC) converts the 500 V DC to 260 V AC and keeps unity power factor. A 400-kVA 260V/25kV three-phase coupling transformer is used to connect the converter to the grid. The grid model consists of typical 25-kV distribution feeders and 120-kV equivalent transmission system.
In the average model the boost and VSC converters are represented by equivalent voltage sources generating the AC voltage averaged over one cycle of the switching frequency. Such a model does not represent harmonics, but the dynamics resulting from control system and power system interaction is preserved.
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