Power optimizer

About: Power optimizer is a research topic. Over the lifetime, 10525 publications have been published within this topic receiving 199245 citations.

Wind power site

Abstract: The invention concerns a wind power site (2) which comprises at least two wind power plants (4) and a line-side power converter station (46), each wind power plant (4) comprising a rotor (6), a generator (24), a rectifier (30), a smoothing choke (36) and an output-regulating arrangement (62). The line-side power converter station (46) comprises a smoothing choke (48), a power inverter (50), a matching transformer (52), a filter (28) and a regulating arrangement (102), the wind power plants (4) being electrically connected in parallel on the direct current side, and the line-side power converter station (46) being electrically connected in series on the direct current side to the wind power plants (4) connected in parallel on the direct current side. In this way, a wind power site (2) is obtained whose entire available wind power output can be transferred into a regional supply network.

Class E high-frequency high-efficiency dc/dc power converter

Abstract: A Class E switching-mode dc/dc power converter is obtained by adding a rectifier circuit at the output of a Class E dc/ac power inverter. It can operate at high efficiency at high switching frequencies. Further, the power switch is not subjected to high power dissipation or high second-breakdown stress while it is switching between the "on" and "off" states, even if the dc load on the power converter varies over a very wide range, e.g., from open-circuit to short-circuit. The high efficiency is achieved by shaping the waveforms of switch voltage and switch current so that the transitions of those two waveforms are displaced in time from each other. Then the power switch does not experience simultaneously high voltage and high current while switching. High efficiency and low stress on the switch are achieved under all load conditions by interposing a matching network between the output of the Class E dc/ac inverter and the input of the rectifier circuit. That matching network transforms the rectifier input impedance in such a way that the impedance presented to the output of the Class E dc/ac inverter is always in the range which generates switch voltage and current waveforms that yield low power dissipation and low second-breakdown stress during switching, for any value of dc load resistance at the output of the rectifier.

Design of a Flux-Switching Electrical Generator for Wind Turbine Systems

Abstract: This paper proposes a parametric optimization of a flux-switching electrical machine customized for a wind turbine application with a typical operating range for average and low-power wind energy sites. Statistics of wind resources are taken into consideration for the machine design for definition of the turbine power envelope. Both copper and iron losses for three different machine designs are evaluated. A very important consideration taken in this design is the elimination of gearbox requirements for coupling to the turbine. Although the developed approach makes the machine somewhat voluminous, the overall performance is highly improved because a direct-drive flux-switching electrical generator becomes very competitive for small-scale wind turbines. The design methodology presented in this paper will support widespread application of small-scale wind turbines for rural systems, farms, and villages. This paper concludes by demonstrating that a very cost-effective distributed wind system can be approached with this design.

P-Q and P-V Control of Photovoltaic Generators in Distribution Systems

Abstract: In this paper, simultaneous control of active power and volt/var is explored with photovoltaic (PV) generators in distribution systems. The PV active power output can be controlled in the load-following mode when sufficient solar power is available to supply a local load, or the maximum power point tracking (MPPT) mode when a local load is large or injection to the system is allowed. Two selected control approaches, P-Q control in the load-following mode and P-V control in the MPPT mode, are investigated in this paper. The P-Q control is implemented with a relatively simple approach, while the P-V control demands an extra MPPT logic, which is solved based on a power balance between the dc and ac sides in a two-stage PV configuration. The control algorithms are tested with the IEEE 13-bus distribution feeder with various system conditions like the presence of multiple PV generators, imbalance, harmonics, and faults. The MATLAB and SimPowerSystems simulation results clearly demonstrate the capability of the proposed control in maintaining the P/V bus as either a P-Q or P-V bus depending on different applications.

System and method for protection in power installations

Abstract: A protection method in a distributed power system including of DC power sources and multiple power modules which include inputs coupled to the DC power sources. The power modules include outputs coupled in series with one or more other power modules to form a serial string. An inverter is coupled to the serial string. The inverter converts power input from the string and produces output power. When the inverter stops production of the output power, each of the power modules is shut down and thereby the power input to the inverter is ceased.