Maximum power principle

About: Maximum power principle is a research topic. Over the lifetime, 14152 publications have been published within this topic receiving 207723 citations.

On the thermodynamics of angular propulsion

Abstract: In a recently published article by Polihronov and Straatman (Phys. Rev. Letters 109, 054504, 2012), the thermodynamics of angular propulsion was presented and a theoretical model of the energy transfer was proposed. This article will show that the theoretical model leads to the most basic element of a radial inflow device. It is shown that Euler's work equation reduces to the same theoretical result for this case. The system is then studied as a self-governed device moving in a medium posing external resistance. It is observed that the output power from the device exhibits a peak at a certain characteristic value of its peripheral velocity. In the presence of resistance or loading, the system has motion, characterized by the requirement of pre-rotation exhibiting maximum power output and a terminal state. The points of equilibrium and operational thresholds of the motion are discussed, accompanied by a theoretical model of the presented dynamical system. The presented angular propulsion theory is then utilized to provide better understanding of phenomena taking place in vortex tubes.

Frequency recovery method and system of photovoltaic microgrid

Abstract: The invention discloses a frequency recovery method and system of a photovoltaic microgrid. The method comprises the steps of determining a virtual electric angular speed output from a virtual synchronous power generator, acquiring a set electric angular speed, and acquiring state quantity to be controlled, wherein the state quantity to be controlled is a specific value between an actual value of an active power output from the virtual synchronous power generator and maximum power value which can be output from the virtual synchronous power generator; determining a derivation formula of the state quantity to be controlled on time t according to a distribution consistency algorithm; calculating to obtain control quantity according to the derivation formula, the virtual electric angular speed output from the virtual synchronous power generator and the set electric angular speed of the virtual synchronous power generator; adjusting the actual value of the active power output from the virtual synchronous power generator by using the control quantity. The frequency modulation characteristic of a power system and the consistency algorithm are combined, thus, all photovoltaic power supplies with different properties can output according to proportions consistent with maximum available capacity, and moreover, a frequency of the system is adjusted and recovered to a set value.

Operation control method and operation control device for wind power generator system, and computer program

Abstract: PROBLEM TO BE SOLVED: To provide an operation control device or the like for a wind power generator system that can follow maximum power at low cost by using only a simple circuit that monitors output voltages of a wind power generator and a power converter that are installed in the wind power generator system. SOLUTION: Characteristic data are stored in a control circuit 8 that indicate a correlation between the output voltage of the wind power generator 2 when the maximum power is taken out and the output voltage of the power converter 3. The control circuit 8 determines the target value of the output power of the power converter 3 on the basis of the characteristic data and the measured value of the output voltage of the wind power generator 2, calculates a drooping current on the basis of the determined target value of the power converter 3 and the measured value of the output voltage of the power converter 3, and repeats to output the drooping current to the power converter 3. COPYRIGHT: (C)2006,JPO&NCIPI

Power factor analysis of driving motor for linear compressor

Abstract: Main effect factors on the power factor of driving motor used for linear compressor were analyzed to ensure high motor performance,including radian frequency ratio and damping ratio.Linear processing of the mathematical model describing mechanical system,electromagnetic system and thermodynamic system was carried out to simplify the calculation.Calculation and experimental results showed that operating frequency and damping ratio were the most important effect factors;the maximum power factor was obtained when operating frequency was near the mechanical resonant frequency;high power factor section was enlarged with increasing damping ratio.The experimental results agreed well with the analytical solutions when the piston was with load or without.All the highest power factors were above 0.96.

Photovoltaic cell output characteristic modeling method based on Bezier function

Abstract: The invention discloses a photovoltaic cell output characteristic modeling method based on a Bezier function. The method comprises the steps of S1, establishing a rectangular plane coordinate system, determining the positions of a short-circuit current point, a maximum power point and an open-circuit voltage point in the rectangular plane coordinate system, and determining the positions of two control points of the Bezier function in the rectangular plane coordinate system according to the positions of the short-circuit current point, the maximum power point and the open-circuit voltage point; S2, determining the coordinates of points, located on the left side and right side of the maximum power point, on the Bezier function curve according to the positions of the short-circuit current point, the maximum power point, the open-circuit voltage point and the two control points; S3, drawing a Bezier fitted curve. According to the method, photovoltaic cell output characteristic modeling can be achieved simply based on the parameters including short-circuit current, maximum power point and open-circuit voltage given by a manufacturer by means of the piecewise second-order Bezier function.