Abstract: A DC/AC inverter and microinverter architectures using the DC/AC inverter are disclosed. The DC/AC inverter is based on a differential geometry control scheme to balance and optimize the flying capacitor voltages across the flying capacitors used in the inverter's power circuit. Based on changing inverter and overall system conditions, including capacitor voltages, grid voltages, grid current, and DC bus voltages, desired fields are generated. These fields are used to balance capacitor voltages such that capacitor voltage values converge, over time, to an optimal solution.

Abstract: Systems and methods relating to the integration of energy storage subsystems into components for use with systems that harvest energy from PV panels and convert that energy for use with a power grid. Various configurations of converters that integrate energy storage cells and the inverters that use such converters are presented. Half-bridge and full bridge configurations for the converters are presented. The integrated energy storage cells may be battery cells, supercapacitor cells, or a combination of the two. Digital control systems for controlling the converters as well as the charge and discharge cycles for the energy storage cells are also presented.

Abstract: Systems and methods for controlling a plurality of DC/DC converters that are coupled to either a renewable energy source or an energy storage device. The system automatically detects the energy source coupled to the relevant DC/DC converter and operates accordingly. If the DC/DC converter is coupled to a renewable energy source (such as a PV panel), the system maximizes power extraction from the energy source. If the DC/DC converter is coupled to an energy storage device, the system performs charge/discharge functions for the attached energy storage device.

Abstract: Systems and methods for providing AC power to a power grid using renewable energy sources as well as energy storage devices. A control system controls multiple DC/DC converters that are coupled to renewable energy sources as well as to one or more energy storage devices. The control system also controls the charge/discharge of the energy storage devices. Each DC/DC converter control block in the control system automatically detects whether to perform MPPT on the renewable energy source or to control the discharge of the energy storage devices. Each DC/DC converter control block ensures that power from the renewable energy source or from the energy storage device is converted and provided to the power grid.

Abstract: Systems and methods for use with renewable energy resources that provide power to an energy power grid or to one or more motor loads. A control system along with an energy storage/combiner block and a DC/AC inverter is used to condition DC power received from renewable energy sources. The control system receives current and voltage outputs from the inverter along with values indicating current and voltage outputs directly from the renewable energy sources. These are then used to estimate and control motor speed when the system is in the off-grid mode. In addition, the control system uses these inputs to provide the gate pulses that are used to control the three phase AC output power from the inverter.

Abstract: Systems and methods relating to power inverters for power generation systems. A power inverter suitable for renewable power sources is configured with a data processing module that receives power related data from a power grid and from a battery backup inverter. The data processing module calculates mode of operation data based on the power related data and, if the mode of operation data exceeds a threshold, then the power generation system is operating in an off-grid mode (i.e. the system is decoupled from the power grid). If the mode of operation data is equal or less than the threshold, then the power generation system is operating in an on-grid operating mode. The system is also self-tuning with respect to the threshold value.

Abstract: Provided are DC-bus voltage or DC-bus current controller methods and circuits, for a voltage or current source inverter. A mean value calculator provides an output signal comprising the mean value of the DC-bus voltage or current, which is used as a feedback signal in a closed loop of the voltage or current source inverter controller, such that a ripple in the DC-bus voltage or current is substantially prevented from entering the closed-loop. In some embodiments a droop controller, which may be adaptive, is used in the closed loop with reverse proportional gain. The adaptive droop controller may provide a constant or variable DC-bus voltage or current. Embodiments regulate the DC-bus voltage or current to an optimized value such that power losses for load and grid conditions are minimized or reduced, and voltage and current ripple is minimized.

Abstract: Provided is a maximum power point (MPP) tracker for a PV cell inverter, and a PV cell inverter. The MPP tracker decouples output power oscillations from the input power generation and extracts maximum available power from the PV cell. The PV cell inverter uses the MPP tracker and generates a sinusoidal output current from the MPP tracker output. The sinusoidal output current may be fed to a power distribution grid. The PV cell inverter may use a pulse width modulation technique to cancel harmonics in the sinusoidal output current. The circuits use a minimum number of components and avoid use of large electrolytic capacitors.

Abstract: The invention provides a digital active EMI filter that removes, minimizes, or reduces unwanted interference (i.e., EMI noise) generated by a power circuit such as, for example, a power converter. Digital active filtering includes digital sampling of the incident noise signal amplitude and frequency, discrete time conversion of the EMI noise source, processing (e.g., inverting) the digital signal, and then constructing an analog output signal (i.e., an EMI compensation signal) which is injected to the input of the power circuit. A digital EMI filter as described herein may be used in both differential-mode and common-mode configurations, and overcomes limitations of passive and active analog EMI filters.

Abstract: Provided herein is a single phase power system controller and a method for controlling a single phase power system. The single phase power system controller comprises an error signal generator that generates an error signal from an instantaneous power reference signal and a measured instantaneous output power signal corresponding to the power delivered to a power distribution grid; and a modulator that modulates the error signal according to a trigonometric function of the grid voltage phase angle and produces a control signal for an inverter controller. In accordance with the circuits and methods provided herein, real and reactive power delivered to the grid are controlled simultaneously based on instantaneous output power feedback.

Abstract: Described herein are methods, systems, and apparatus for a controller for a power circuit that interfaces distributed power generation with a power distribution grid, comprising: a first portion, including a maximum power point tracker, that receives signals corresponding to the distributed power generation voltage and current, and outputs to the power circuit a signal for controlling the voltage of the distributed power generation; a second portion, including a current reference generator, a current controller, and a dc voltage controller, that receives signals corresponding to a dc voltage of the power circuit, the power distribution grid voltage and current, and the inverter current, and outputs signals for controlling the power circuit output voltage; wherein the current reference generator includes nonlinear circuit elements and generates a current reference signal from the dc voltage of the power circuit and the grid voltage and current; such that substantially harmonic-free power is injected into the p

Abstract: Provided is a maximum power point (MPP) tracker for a PV cell inverter, and a PV cell inverter. The MPP tracker decouples output power oscillations from the input power generation and extracts maximum available power from the PV cell. The PV cell inverter uses the MPP tracker and generates a sinusoidal output current from the MPP tracker output. The sinusoidal output current may be fed to a power distribution grid. The PV cell inverter may use a pulse width modulation technique to cancel harmonics in the sinusoidal output current. The circuits use a minimum number of components and avoid use of large electrolytic capacitors.

Abstract: Described herein are methods, systems, and apparatus for a controller for a power circuit that interfaces distributed power generation with a power distribution grid, comprising: a first portion, including a maximum power point tracker, that receives signals corresponding to the distributed power generation voltage and current, and outputs to the power circuit a signal for controlling the voltage of the distributed power generation; a second portion, including a current reference generator, a current controller, and a dc voltage controller, that receives signals corresponding to a dc voltage of the power circuit, the power distribution grid voltage and current, and the inverter current, and outputs signals for controlling the power circuit output voltage; wherein the current reference generator includes nonlinear circuit elements and generates a current reference signal from the dc voltage of the power circuit and the grid voltage and current; such that substantially harmonic-free power is injected into the p

Abstract: Provided are methods and circuits for a controller for a control system, comprising first and second control loops that operate substantially independently, wherein the first control loop is an amplitude control loop and the second loop is a phase or frequency control loop. In some embodiments the amplitude control loop operates at an amplitude that is proportional to an amplitude of an input signal at a fundamental system frequency and at a selected harmonic of a fundamental system frequency; and the frequency control loop operates at a fundamental system frequency and at a selected harmonic of the fundamental system frequency. The frequency control loop may adaptable to a fundamental control system frequency or to a selected harmonic of the fundamental control system frequency. The controller may be implemented as a resonant controller and used in various ac systems, and offers high structural robustness in digital implementations.

Abstract: Provided is a maximum power point (MPP) tracker for a PV cell inverter, and a PV cell inverter. The MPP tracker decouples output power oscillations from the input power generation and extracts maximum available power from the PV cell. The PV cell inverter uses the MPP tracker and generates a sinusoidal output current from the MPP tracker output. The sinusoidal output current may be fed to a power distribution grid. The PV cell inverter may use a pulse width modulation technique to cancel harmonics in the sinusoidal output current. The circuits use a minimum number of components and avoid use of large electrolytic capacitors.

Abstract: This invention relates to circuits and methods for controlling a resonant power converter. Control of the power converter may comprise comparing an output voltage or current of the converter to at least one reference voltage or current; enabling primary side switching signals based on a first selected result of the comparison; and disabling primary side switching signals based on a second selected result of the comparison; wherein a primary side switching signal for each primary side switch includes at least one off-on-off transition.

Abstract: A maximum power point tracking method and system for use with a power generator comprises sampling instantaneous output voltage and current of the power generator at a first instant in time and at a second instant in time to obtain first and second power samples, generating a reference voltage or current signal from a difference of the first and second power samples; comparing the reference voltage or current to the instantaneous power generator voltage or current and generating at least one gating signal; and repeating so as to minimize the difference of the first and second power samples; wherein the gating signal affects magnitude of the output voltage and current of the power generator; wherein the maximum power point is tracked when the difference signal is minimized. The power generator may be at least one photovoltaic cell, wind turbine, or fuel cell.