EPE Association: NORpie 2006 - Topic 08: Photovoltaics

NORpie 2006 - Topic 08: Photovoltaics
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > NORpie - Proceedings > NORpie 2006 > NORpie 2006 - Topic 08: Photovoltaics

   [return to parent folder]

   Implementation and Stability Analysis of a 200kW Photovoltaic Generator Simulator
By S. A. Richter; K. Rigbers; D. Hirschmann; C. P. Dick; R. W. De Doncker [View]
[Download]

Abstract: In order to perform comparative and detailed measurements of the performance of grid connected photovoltaic (PV) inverters under realistic operating conditions, this paper proposes two designs and implementations of a 200kW PV generator simulator: an interleaved three-phase synchronous buck converter with LC output filter and a conventional synchronous buck converter with LCL output filter. Both implementations consist of commercial half-bridge modules and use almost the same hardware. An appropriate control strategy that implements the I-V output characteristic of a PV generator (with or without partial shading) using a single PI controller is proposed. To establish realistic operating conditions, the output power can be varied according to a given course of generated power during a day.

   DC-DC-converter for photovoltaic panel charge controller
By E. Stjernholm Hoff; P. Andreassen; L. E. Norum [View]
[Download]

Abstract: The use of Maximum Power Point Tracking (MPPT) has a potential for increasing the energy yield from photovoltaic panels. The DC-DC-converter efficiency, no-load power consumption and panel temperature are important in this respect. Three test circuit charge controllers with MPPT are built. The energy yield using MPPT is compared to simply direct connection to a battery, using two months measurements from two photovoltaic panels. The calculated energy gain is 6.4% for the measured conditions. This is so low that the main reason for choosing a charge controller with MPPT should be added values of a switch-mode converter such as reduced weight, regulated output voltage or battery cell voltage balancing.

   Grid Connected Photovoltaic (PV) Inverter with Robust Phase-Locked Loop (PLL)
By T. Ostrem; W. Sulkowski; L. E. Norum; C. Wang [View]
[Download]

Abstract: An array of solar panels is connected to the mains through a three-phase active voltage-source inverter and a step-up transformer. The inverter synchronizes to the grid by means of a robust phase-locked loop (PLL), using input's quadrate method, and a multi-variable filter removes voltage harmonics caused by unbalance and distortion. The PWM active inverter utilizes a voltage oriented control (VOC) control structure, using a Park Transform, to convert the measured ac currents to synchronous reference properties (d-q reference). Since both the PLL and the VOC are sharing some common properties (Park Transform, reference angle), they are combined in one circuit. A field programmable gate array (FPGA) is used for the purpose. Cumbersome algorithms like sine and cosine calculations are replaced by look-up tables. This provides a fast and reliable tool, and no other control circuits are needed for inverter operation. Equipment for maximum power point tracking and monitoring and protecting schemes are beyond the scope of this article. Simulations and experimental results are presented.

NORpie 2006 - Topic 08: Photovoltaics
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > NORpie - Proceedings > NORpie 2006 > NORpie 2006 - Topic 08: Photovoltaics
	[return to parent folder]

	Implementation and Stability Analysis of a 200kW Photovoltaic Generator Simulator By S. A. Richter; K. Rigbers; D. Hirschmann; C. P. Dick; R. W. De Doncker	[View] [Download]
Abstract: In order to perform comparative and detailed measurements of the performance of grid connected photovoltaic (PV) inverters under realistic operating conditions, this paper proposes two designs and implementations of a 200kW PV generator simulator: an interleaved three-phase synchronous buck converter with LC output filter and a conventional synchronous buck converter with LCL output filter. Both implementations consist of commercial half-bridge modules and use almost the same hardware. An appropriate control strategy that implements the I-V output characteristic of a PV generator (with or without partial shading) using a single PI controller is proposed. To establish realistic operating conditions, the output power can be varied according to a given course of generated power during a day.

	DC-DC-converter for photovoltaic panel charge controller By E. Stjernholm Hoff; P. Andreassen; L. E. Norum	[View] [Download]
Abstract: The use of Maximum Power Point Tracking (MPPT) has a potential for increasing the energy yield from photovoltaic panels. The DC-DC-converter efficiency, no-load power consumption and panel temperature are important in this respect. Three test circuit charge controllers with MPPT are built. The energy yield using MPPT is compared to simply direct connection to a battery, using two months measurements from two photovoltaic panels. The calculated energy gain is 6.4% for the measured conditions. This is so low that the main reason for choosing a charge controller with MPPT should be added values of a switch-mode converter such as reduced weight, regulated output voltage or battery cell voltage balancing.

	Grid Connected Photovoltaic (PV) Inverter with Robust Phase-Locked Loop (PLL) By T. Ostrem; W. Sulkowski; L. E. Norum; C. Wang	[View] [Download]
Abstract: An array of solar panels is connected to the mains through a three-phase active voltage-source inverter and a step-up transformer. The inverter synchronizes to the grid by means of a robust phase-locked loop (PLL), using input's quadrate method, and a multi-variable filter removes voltage harmonics caused by unbalance and distortion. The PWM active inverter utilizes a voltage oriented control (VOC) control structure, using a Park Transform, to convert the measured ac currents to synchronous reference properties (d-q reference). Since both the PLL and the VOC are sharing some common properties (Park Transform, reference angle), they are combined in one circuit. A field programmable gate array (FPGA) is used for the purpose. Cumbersome algorithms like sine and cosine calculations are replaced by look-up tables. This provides a fast and reliable tool, and no other control circuits are needed for inverter operation. Equipment for maximum power point tracking and monitoring and protecting schemes are beyond the scope of this article. Simulations and experimental results are presented.