Methods and systems are provided for optimizing the control of energy supply and demand. An energy control unit includes one or more algorithms for scheduling the control of energy consumption devices on the basis of variables relating to forecast energy supply and demand. Devices for which energy consumption can be scheduled or deferred are activated during periods of cheapest energy usage. Battery storage and alternative energy sources (e.g., photovoltaic cells) are activated to sell energy to the power grid during periods that are determined to correspond to favorable cost conditions.

Optimized energy management system

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.

Distributed Power Harvesting Systems Using DC Power Sources

A wireless base unit communicates with one or more wireless load manager units to receive power measurements for one or more loads connected to the wireless load manager. In response to dynamic variables, such as the changing price of electricity, the wireless base unit transmits commands to the wireless load manager to shut off or reduce power consumed by the one or more loads. In one variation, a wireless adapter also receives commands from the wireless base unit and converts the commands into a vendor-specific format used to control other devices such as a photovoltaic (PV) inverter.

Modular energy control system

A monitoring system and method for monitoring performance of individual powers sources in a distributed power source system A monitoring module is coupled to each of the power sources, or to each string of serially connected power sources, to monitor and collect data regarding current, voltage, temperature and other environmental factors at the power source The collected data is transmitted over a power line to a central analysis station for analysis Data collected from each source indicates malfunction or degradation at the source Comparison of data collected from adjacent sources filters for environmental factors impacting neighboring sources such as cloudy days for a solar panel Comparison of data collected from the same source at different times indicates soiling or degradation of the source with time or periodic events such as a moving shade from an adjacent building

Monitoring of Distributed Power Harvesting Systems Using DC Power Sources

An integrated circuit chip includes a first input port, a first output port, and first and second transistors electrically coupled in series across the first input port. The second transistor is also electrically coupled across the first output port and is adapted to provide a path for current flowing through the first output port when the first transistor is in its non-conductive state. The integrated circuit chip additionally includes first driver circuitry for driving gates of the first and second transistors to cause the transistors to switch between their conductive and non-conductive states. The integrated circuit chip further includes first controller circuitry for controlling the first driver circuitry such that the first and second transistors switch between their conductive and non-conductive states to at least substantially maximize an amount of electric power extracted from an electric power source electrically coupled to the first input port.

Switching Circuits For Extracting Power From An Electric Power Source And Associated Methods

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.

Method and apparatus for tracking maximum power point for inverters, for example, in photovoltaic applications

The maximum power point (MPP) of a photovoltaic array that can be coupled to power inverter is determined. A capacitor on a DC-bus side of the inverter is used as a load from which I-V characteristics of the photovoltaic array can be generated. The photovoltaic array is connected to the capacitor, which has been previously discharged by a bleed down resistor. Short circuit current, open circuit voltage, and values of current and voltage as the capacitor charges are determined and used to generate I-V characteristics of the photovoltaic array. From the I-V characteristics, the MPP can be calculated.

Method and apparatus for determining a maximum power point of photovoltaic cells

In a hybrid electric motor vehicle, a power supply system for storing and supplying electrical power includes a motor-generator located onboard the vehicle, driveably connected to the vehicle wheels and producing AC electric power, an energy storage device for alternately storing and discharging electric power, an inverter coupled to the motor-generator and the energy storage device for converting alternating current produced by the motor-generator to direct current transmitted to the energy storage device, and for converting direct current stored in the energy storage device to alternating current transmitted to the motor-generator, a source of AC electric power located external to the vehicle, and a charger coupled to said electric power source and the energy storage device for supplying DC electric power to the energy storage device from said AC electric power source.

Battery equalization using a plug-in charger in a hybrid electric vehicle

A torque control strategy control for management of regenerative braking in a motor vehicle. A first processor ( 12 ) processes throttle request data ( 20 ) and torque modification data ( 40 ) from a second processor ( 14 ) to develop motor torque request data ( 28 ) for controlling rotary electric machine torque. The second processor processes brake request data ( 26 ), the throttle request data, and operating data from the at least one operating data source to develop friction brake torque data ( 30 ) for controlling friction brake torque applied to the vehicle and the torque modification data for the first processor. The two processors interact such that as long as the operating data from the at least one operating data source does not require that regenerative braking torque be limited, the torque modification data supplied to the first processor from the second processor equates to the brake torque request data, and the friction brake torque data does not cause the friction brakes to be applied, and when the operating data from the at least one operating data source calls for some limiting of the regenerative braking torque, the amount of limiting is subtracted from the torque modification data and the friction brake torque data equates to that amount of limiting for causing the friction brakes to be applied in that amount.

Torque control strategy for management of regenerative braking of a wheeled vehicle whose powertrain includes a rotary electric machine

System and method for enhancing the torque output of a field oriented induction motor including a controller having a plurality of predetermined control parameters operable for processing input signals to generate output signals. The plurality of predetermined control parameters are dependent upon the nature of the input signals and the operational state of the motor. A sensor system is operable for communicating feedback signals related to the output signals and the operational state of the motor from the motor to the controller.

Kerry Eden Grand

Papers

Method and apparatus for tracking maximum power point for inverters, for example, in photovoltaic applications

Method and apparatus for determining a maximum power point of photovoltaic cells

Battery equalization using a plug-in charger in a hybrid electric vehicle

Torque control strategy for management of regenerative braking of a wheeled vehicle whose powertrain includes a rotary electric machine

System and method for induction motor control