Abstract:
A method for managing a microgrid, the microgrid having an intermittent energy source and energy storage, comprising: using a microgrid asset management system, dispatching the energy storage to maintain optimal power flow to and from a power grid by: producing a generation forecast and a generation forecast error probability distribution for an intermittent energy source coupled to the microgrid from a historic generation forecast and one or more measurements; generating random intermittent energy source generation inputs from at least one of historic generation data, the historic generation forecast, and the generation forecast error probability distribution; using the random intermittent energy source generation inputs, calculating a microgrid performance value using a microgrid performance model and a microgrid financial value using a microgrid financial model; and, selecting an energy storage dispatch scenario to optimize operation of the microgrid using at least one of the microgrid performance value and the microgrid financial value.
Abstract:
A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a gate coupling circuit for conducting a gate current through a gate of the thyristor, and a control circuit for controlling the gate coupling circuit to conduct the gate current through a first current path to render the thyristor conductive at a firing time during a half cycle. The gate coupling circuit is able to conduct the gate current through the first current path again after the firing time, but the gate current is not able to be conducted through the gate from a transition time before the end of the half-cycle until approximately the end of the half-cycle. The load current is able to be conducted through a second current path to the electrical load after the transition time until approximately the end of the half-cycle.
Abstract:
An electrical power socket comprising a well having an electrically conductive well portion having a proximal and a distal end; a connector part for receiving connections to a power supply disposed at the distal end of the well portion; a first contact being provided in isolation from the well portion at the distal end of the well portion, the first contact being connected to a first connection of the connector part; the well portion being connected to a second connection of the connector part; and an insulating sleeve portion being provided at the proximal end of the well portion forming an insulating portion of the well, the sleeve portion adapted to be disposed in an opening in a receiving panel, whereby the insulating sleeve portion prevents a conductive foreign object that is inserted in the well and contacts the first contact from simultaneously making contact with the conductive well portion.
Abstract:
A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit generates a lamp current through the lamp tube having a substantially constant envelope such that flicker in the lamp tube and electromagnetic interference (EMI) noise on an AC voltage supply are minimized. The dimmable ballast circuit comprises a high speed control circuit characterized by a cutoff frequency much greater than a frequency of a voltage ripple on a bus voltage of the ballast circuit. The dimmable ballast circuit may also comprise a non-linear amplifier circuit amplifying a lamp-current-feedback signal representative of the magnitude of the lamp current through the lamp.
Abstract:
A binocular indirect ophthalmoscope that is adapted to be worn on a wearer's head includes a headband and illumination housing having an illumination source and a viewer module wherein the viewer module is moveable between an in-use and an out-of-use position. A mounting assembly is provided for allowing the viewer module to be pivoted between the in-use and the out-of-use positions and also allows adjustment and locking to the wearer's face in the in-use position. The mounting assembly includes a magnetic securement of the viewer module in both the in-use and out-of-use positions. Part of the magnetic securement operates as an electrical contact to automatically provide power to the illumination source in the in-use position. An optical polarizer provides intensity adjustment of the light energy transmitted to the eye being examined. Preferably the illumination source is a light emitting diode.
Abstract:
A load control device adapted to be coupled between an AC power source and an electrical load for controlling the power delivered to the load includes a power supply having an energy storage capacitor (C out) and a charge pump circuit (222) adapted to conduct an input charging current through the load and to conduct an output charging current through the energy storage capacitor to thus generate a DC supply voltage (Vcc) across the energy storage capacitor, where the output charging current has a magnitude greater than the input charging current. The charge pump circuit includes a switched capacitor (C10-C60) operable to charge through the load during a first half -cycle, and to discharge into the energy storage capacitor in a second, subsequent half -cycle. The charge pump circuit operates at line frequency and the magnitude of the input charging current is substantially small so as to avoid generating noise in a noise - sensitive circuit of the load control device.
Abstract:
A configurable light-emitting diode (LED) driver is adapted to control a plurality of different LED light sources, which may be rated to operate using different load control techniques, different dimming techniques, and different magnitudes of load current and voltage. The LED driver comprises a power converter circuit for generating a DC bus voltage, and an LED drive circuit for receiving the bus voltage and adjusting either the magnitude of the current conducted through the LED light source or the magnitude of the voltage across the LED light source. The LED driver is operable to dim the LED light source using either a pulse-width modulation technique or a constant current reduction technique, and may be configured using a programming device and a personal computer.
Abstract:
A wireless battery-powered daylight sensor for measuring a total light intensity in a space is operable to transmit wireless signals using a variable transmission rate that is dependent upon the total light intensity in the space. The sensor comprises a photosensitive circuit, a wireless transmitter for transmitting the wireless signals, a controller coupled to the photosensitive circuit and the wireless transmitter, and a battery for powering the photosensitive circuit, the wireless transmitter, and the controller. The photosensitive circuit is operable to generate a light intensity control signal in response to the total light intensity in the space. The controller transmits the wireless signals in response to the light intensity control signal using the variable transmission rate that is dependent upon the total light intensity in the space. The variable transmission rate may be dependent upon an amount of change of the total light intensity in the space. In addition, the variable transmission rate may be further dependent upon a rate of change of the total light intensity in the space.
Abstract:
A wireless lighting control system comprises a daylight sensor for measuring a light intensity in a space and a dimmer switch for controlling the amount of power delivered to a lighting load in response to the daylight sensor. For example, the daylight sensor may be able to transmit radio-frequency (RF) signals to the dimmer switch. The system provides methods of calibrating the daylight sensor that allow for automatically measuring and/or calculating one or more operational characteristics of the daylight sensor. One method of calibrating the daylight sensor comprises a "single-button-press" calibration procedure during which a user is only required to actuate a calibration button of the daylight sensor once. In addition, the daylight sensor is operable to automatically measure the total light intensity in the space at night to determine the light intensity of only the electrical light generated by the lighting load.
Abstract:
A load control system provides for automatically controlling a position of a motorized window treatment to control the amount of sunlight entering a space of a building through a window located in a facade of the building in order to control a sunlight penetration distance within the space and minimize occupant distractions. The load control system automatically generates a timeclock schedule having a number of timeclock events for controlling the position of the motorized window treatment during the present day. A user is able to select a desired maximum sunlight penetration distance for the space and a minimum time period that may occur between any two consecutive timeclock events. In addition, a maximum number of movements that may occur during the timeclock schedule may also be entered. The load control system uses these inputs to determine event times and corresponding positions of the motorized window treatment for each timeclock event of the timeclock schedule.