1405 results about "Maximum power point tracking" patented technology

The invention relates to a conditioning circuit that measures operating points of a power supply to deduce therefrom the current-voltage characteristic thereof and to determine directly the voltage corresponding to its maximum power point, without using any kind of tracking algorithm that causes the operating point of the power unit to oscillate about the maximum power point. The maximum power point voltage VMPP is supplied to a controller which regulates a power cell by slaving it to the input voltage until the output voltage of the supply is equal to the maximum power point voltage VMPP. The invention also relates to a solar generator and an associated conditioning method. One particular application is to high-power satellites.

A power system employs an outer voltage feedback loop and an inner current feedback loop to control a power converter, such as a DC to AC inverter for transferring electrical power between a power source, for example a photovoltaic array, and a load, for example a power grid. The outer loop accommodates variations in the output of the power source, for example accommodating anomalies in IV characteristics such as IV droop characteristic associated with photovoltaic cells. The outer loop may employ a first control regime or a second control regime, for example, dependent on whether a DC bus voltage or power is smaller than a value corresponding to measurement resolution or expected noise.

The invention concerns a method and a circuit for maximum power point tracking of a variable power source from a comparison of an image of the power (P) supplied by the power source, the circuit comprising two elements (14, 31) providing different propagating delays to a physical quantity proportional to the power image, a comparator (16) of the outputs of the delaying elements to control a trigger (17) supplying a signal (Q) with two automatic control states to a static power converter, and means (33) for detecting a transitory operating condition from variations in oscillations of an established operating condition and means (32) for modifying the delay input by the slower delaying element (31).

A string over-voltage protection system and method for arrays of photovoltaic panels. The system and method includes a device for use in a photovoltaic array power system. The device includes a voltage converter. The voltage converter is adapted to be coupled to a photovoltaic panel in a string of photovoltaic panels. The device also includes a string over-voltage protection circuit. The string over-voltage protection circuit is coupled to the voltage converter. The string over-voltage protection circuit senses a string voltage and determines if a string over-voltage condition exists. Additionally, the string over-voltage protection circuit is configured to disable the voltage converter in the event of a string over-voltage condition.

A system for providing power from solar cells where each cell or cell array is allowed to produce its maximum available power and converted by its own DC / DC converter. In one form the system includes: one or more solar generators, each of which has at least one solar cell; a maximum power tracker operatively associated with each solar generator, where the maximum power tracker includes a buck type DC / DC converter without an output inductor, and the maximum power trackers of the solar generators are operatively connected in series with each other; and an inductor operatively connected to the series connected maximum power trackers.

Disclosed is an apparatus and methodology for generating operating power for various desired applications using solar energy. A solar array is formed using a small number of solar cells connected in series to form a string of solar cells and then connecting multiple strings in parallel. Unlike conventional solar arrays, no bypass diodes are incorporated into the array. A power converter is coupled to the array to boost output voltage to a level sufficient to operate the desired application. The power converter may be operated independently or based on output levels of the array, the material from which the solar cells of the array are constructed and the operating temperature of the array or combinations thereof.

The power of DC electrical sources is combined onto a DC buss, such that each source behaves independently from any other source attached to the buss. In one embodiment, a converter module is attached to each of a plurality of solar photovoltaic panels and its output is attached in a parallel manner to a common buss that forms the input to a DC AC inverter. The converter module includes a Maximum Power Point Tracking component that matches the output impedance of the panels to the input impedance of the converter module. The converter also includes a communication component that provides parametric data and identification to a central inverter. Data generated by each converter module is transmitted over the power line or by wireless means and is collected at the inverter and forwarded to a data collection and reporting system.

A novel integrated rectifier and boost converter circuit architecture is disclosed. The rectifier architecture includes a plurality of identical half-bridge rectifiers connected to receiving antennas to convert wireless AC power into DC power. The integrated rectifier may be coupled in series with a charging inductor in a boost converter. The inductor may discharge upon operation of two micro-controller-driven switching transistors using predetermined threshold and timing scheme to turn on / off. The rectifier architecture may provide high power densities, improve efficiency at larger load currents, and may be enabled in an integrated circuit with eight RF signal inputs, eight half-bridge rectifiers, and eight DC outputs ganged together as single feed into the boost converter. The rectifier circuit topology may include a comparator driven by the boost controller with a proprietary algorithm which suits control for a maximum power point tracking functionality, and an external micro-controller for additional control of the boost converter.

Methods, apparatus, media and signals for controlling power drawn from an energy converter to supply a load, where the energy converter is operable to convert energy from a physical source into electrical energy. Power drawn from the energy converter is changed when a supply voltage of the energy converter meets a criterion. The criterion and the change in the amount of power drawn from the energy converter are dependent upon a present amount of power supplied to the load. The methods, apparatus, media and signals described herein may provide improvements to DC to AC maximum power point tracking in an energy conversion system such as a photovoltaic power generation system.

A detection voltage, which is obtained by dividing the voltage of a fuel cell 1 by resistors, is compared with a first reference voltage Vref 1 by a differential amplifier. The differential voltage is input to a control section. The control section performs PWM control for the circuit section according to the difference. The first reference voltage Vref 1 is set according to the dividing ratio of the resistors, based on the output voltage when the fuel cell generates power at the maximum power point. To determine the output voltage for maximum power generation, a characteristic curve representing a current-voltage characteristic is approximated by an approximating line within a range excluding an area in which the output voltage changes abruptly when the output current is nearly zero, and an extrapolated voltage is obtained on the extension line of the approximating line at an output current of zero. Fifty percent of the extrapolated voltage is then determined as the output voltage when the fuel cell generates power at the maximum power point. Thus, a fuel cell control system that identifies a highly precise output voltage for power generation at a maximum power point and controls power so that the maximum power point is not exceeded could be provided.

A circuit arrangement, includes output terminals that provide an output current and input terminals that receive a source current and a source voltage from a DC current source. A maximum power point tracker is coupled between the input terminals and the output terminals and a bypass circuit is coupled between the input terminals and the output terminals. The bypass circuit is configured to enter a bypass state dependent on the output current and dependent on the source current. The source current flows through the bypass circuit in the bypass state.

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

A power conditioner 10 is provided with a maximum power follow-up control portion 12 for setting a DC operating voltage of a power converter 11, which converts output power of a power generator 2 into AC power, for making a power point corresponding to the output level of the power generator follow up with a maximum power point, and comprises an approximate function memory 25 for storing approximate functions related to the maximum power point, a follow-up control portion 34 for making the present power point reach proximate of the maximum power point on the basis of the approximate function, and a hill-climbing method follow-up control portion 35 for making the present power point reach the maximum power point by using a hill-climbing method when the present power point has reached proximate of the maximum power point.

A tracking and control method for the hybridded maximum power point of the photovoltaic pumping system. It contains: a, the check and choice logo, it will turn to the step b if it is ture, or it will turn to the step d. b, the output frequency of the inverter will be adjusted the running of the multiple criteria. C, the choice logo will become untrue and the reference voltage Verf=V (n), and the real running time of the normal voltage method, tCV, will be reset, and turn to the step a, or turn to the step a. d, the output frequency of the inverter will be adjusted by the running of the normal voltage method. e, To add a control cycle into the running time of the normal voltage method, tvc, the choice logo will be true if the tvc >= TVC and turn to the step a, or it will turn directly to the step a. it adjust the output frequency by the alternative running of multiple criteria and normal voltage, it can adjust the output frequency in time and control the DC voltage effectively and assure the stable running of the system, the system owns rapid and dynamic tracking characteristics, and a good stable characteristics by taking advantage of this method .

A photovoltaic system including a photovoltaic cell, and an electronic module connected to the photovoltaic cell. The electronic module is adapted to produce at least one control signal indicative of electrical power being generated by the photovoltaic cells. A tracking controller is adapted to receive the control signal(s) and based on the control signal(s), the controller is adapted to control a tracking motor for adjusting the system so that electrical power generated by the photovoltaic cells is increased. The photovoltaic system may include an optical element, adapted for concentrating solar light onto the photovoltaic cells. The electronic module preferably performs direct current (DC) to direct current (DC) power conversion and maximum power point tracking by electrical power, current, or voltage at either their inputs or their outputs. Alternatively, the tracking controller is configured to also perform maximum power point tracking by increasing to a local maximum electrical power by varying at least one of (i) current or voltage output from the photovoltaic cell or (ii) current or voltage output from the electronic module.

The disclosed embodiments and principles provide a way to integrate high-efficiency, low-profile power electronics with localized maximum power point tracking (MPPT) into a rooftop shingle-based photovoltaic power system. DC-DC power converters having a height, or profile, as low as ¼ inch for a 200 W power output, are able to be included in a building-integrated photovoltaic (BIPV) roof shingle. The DC-DC power converters increase the relatively low voltage produced by two rows of series-connected photovoltaic shingles, each including photovoltaic cells, to a high voltage used by a DC-AC inverter. For example, DC-DC power converter increases the voltage produced by two rows of series-connected photovoltaic shingles from several tens of volts to approximately 400 volts. Thus, the DC-DC power converters provide a large voltage step-up using a low profile and with very high efficiency.