José Ignacio Candela García

New Structure for Three Phase Four Wires Hybrid Active Filters

This paper presents a new structure for three phase four wires hybrid active power filters (APF). The main point with regard to other published structures consists of the connection of neutral wire to negative of DC bus in the inverter, thus avoiding the need of split capacitors at the DC bus. A particular control of voltage at the passive section of the filter allows the use of low voltage at the DC bus and provides a symmetry between ton and toff in the current controller. The paper includes a general discussion of the new structure and presents the control method for such a structure. Simulation and experimental results are given to show the behaviour of the system, used for harmonics cancellation

Power station for large scale photovoltaic power plants

Most of the large scale photovoltaic power plants (LS-PVPP) count on power converters with a central configuration. Advantages such as robustness, low maintenance and installation cost makes this configuration the preferred specially suitable in large scale systems. However, important drawbacks like the low efficiency level make necessary to develop new solutions for future power plants. In this paper a power station for large scale PV systems is proposed, which consists of power inverters synchronized with an interleaving modulation and connected to a multi-winding transformer. The main principles that support this proposal, as well as, simulation results are presented to validate the effectiveness of the proposed configuration.Most of the large scale photovoltaic power plants (LS-PVPP) count on power converters with a central configuration. Advantages such as robustness, low maintenance and installation cost makes this configuration the preferred specially suitable in large scale systems. However, important drawbacks like the low efficiency level make necessary to develop new solutions for future power plants. In this paper a power station for large scale PV systems is proposed, which consists of power inverters synchronized with an interleaving modulation and connected to a multi-winding transformer. The main principles that support this proposal, as well as, simulation results are presented to validate the effectiveness of the proposed configuration.

Grid resonance attenuation in long lines by using renewable energy sources

In this paper the grid harmonic resonance on long lines is studied, in particular the resonance phenomena between the grid series inductance and the line parallel capacitor. Later, the resonance is attenuated by using a renewable energy generator. Experimental results are depicted and the conclusions are stated.In this paper the grid harmonic resonance on long lines is studied, in particular the resonance phenomena between the grid series inductance and the line parallel capacitor. Later, the resonance is attenuated by using a renewable energy generator. Experimental results are depicted and the conclusions are stated.

Re-synchronization strategy for the synchronous power controller in HVDC systems

Frequency and voltage regulation are required to support the grid under different scenarios. In order to handle these scenarios, classical control strategies demand complex systems to fulfill these requirements. However, synchronous controllers are trending strategies to contribute with frequency and voltage regulation functionalities without the requirement of external elements. Among these strategies, the Synchronous Power Controller (SPC) is exceptional, due to its ability to operate a power converter in grid-forming or grid-feeding mode while providing grid supportive functionalities. Nevertheless, to avoid high power oscillations at the point of common coupling during grid connection, a grid synchronization strategy is mandatory. This paper proposes a synchronization strategy to adjust the angle, voltage amplitude and frequency of the converters controlled with the SPC. The proposed strategy has been simulated in an HVDC system with the SPC controlling the grid connected converter. Simulation results demonstrate the validity and effectiveness of the proposed strategy.Frequency and voltage regulation are required to support the grid under different scenarios. In order to handle these scenarios, classical control strategies demand complex systems to fulfill these requirements. However, synchronous controllers are trending strategies to contribute with frequency and voltage regulation functionalities without the requirement of external elements. Among these strategies, the Synchronous Power Controller (SPC) is exceptional, due to its ability to operate a power converter in grid-forming or grid-feeding mode while providing grid supportive functionalities. Nevertheless, to avoid high power oscillations at the point of common coupling during grid connection, a grid synchronization strategy is mandatory. This paper proposes a synchronization strategy to adjust the angle, voltage amplitude and frequency of the converters controlled with the SPC. The proposed strategy has been simulated in an HVDC system with the SPC controlling the grid connected converter. Simulation results demonstrate the validity and effectiveness of the proposed strategy.