摘要:
High power output may be obtained from a photovoltaic (PV) system by controlling each photovoltaic cell of a solar array individually to operate at its maximum power point. Each cell may have associated power electronics and control circuitry that may be integrated together on a chip which may be advantageously implemented in CMOS, enabling reductions in cost and size. A perturb and observe algorithm may be used to find the maximum power point by measuring the power produced at different operating points, and modifying the operating point in the direction of increased power production. In one aspect, performance of a perturb and observe algorithm may be improved in the presence of noise.
摘要:
High power output may be obtained from a photovoltaic (PV) system by controlling each photovoltaic cell of a solar array individually to operate at its maximum power point. Each cell may have associated power electronics and control circuitry that may be integrated together on a chip which may be advantageously implemented in CMOS, enabling reductions in cost and size. A perturb and observe algorithm may be used to find the maximum power point by measuring the power produced at different operating points, and modifying the operating point in the direction of increased power production. In one aspect, performance of a perturb and observe algorithm may be improved in the presence of noise.
摘要:
Methods and apparatus for a dc-dc converter for operating at substantially fixed switching frequency, the converter including a rectifier, and a resonant inverter coupled to the rectifier, the resonant inverter including a switch and a reactive network having first, second, third and fourth energy storage elements, wherein an impedance magnitude at the output of the switch due to the reactive network has minima at dc and at a frequency near a second harmonic of the switching frequency.
摘要:
A switched mode dc-dc converter enables increases in switching frequency over conventional architectures. In one embodiment, a dc-dc converter has a Vernier-regulated architecture having unregulated cells and a regulating cell coupled to a controller. In another embodiment, a dc-dc-converter has a cell-modulation-regulated architecture.
摘要:
A reversible chest protector includes internal padding configured to absorb impacts against both the front and rear-facing surfaces of the chest protector. The chest protector includes inner and outer layers of fabric that are molded to an internal foam core. The foam core may include outer layers of closed-cell foam molded to the fabric layers, and an internal layer of open-cell foam molded to the closed-cell foam layers, such that the padding layup is symmetrical. Other features and advantages will appear hereinafter.
摘要:
A reversible chest protector includes internal padding configured to absorb impacts against both the front and rear-facing surfaces of the chest protector. The chest protector includes inner and outer layers of fabric that are molded to an internal foam core. The foam core may include outer layers of closed-cell foam molded to the fabric layers, and an internal layer of open-cell foam molded to the closed-cell foam layers, such that the padding layup is symmetrical. Other features and advantages will appear hereinafter.
摘要:
A load control device is adapted to be disposed in series with an AC voltage source and an electrical load and is operable to provide substantially all voltage provided by the AC voltage source to the load. The load control device comprises a controllably conductive device, a controller, a zero-crossing detector, and a power supply for generating a substantially DC voltage for powering the controller. The power supply is operable to charge an energy storage device to a predetermined amount of energy each half-cycle. The controller is operable to determine when the power supply has stopped charging from the zero-crossing detector each half-cycle, and to immediately render the controllably conductive device conductive to conduct the full load current. Before the controllably conductive device begins to conduct each half-cycle, only a minimal voltage develops across the power supply to allow the energy storage device to charge.
摘要:
An electrical component includes a capacitive impedance and a shunt path inductance cancellation feature provided by coupled windings. A filter having a capacitor with capacitor-path inductance cancellation provides enhanced performance over frequency compared with conventional capacitors.
摘要:
A coupled winding cancels parasitic inductance of first and second capacitors. In an EMI filter having common mode capacitors and a differential capacitors, first and second windings cancel parasitic inductance of the common mode and differential capacitors.