Abstract: Systems, methods, and devices for use with photovoltaic micro-inverters. A control system for controlling power switches in a full bridge inverter in a DC/DC converter uses an estimate of the output current of a photovoltaic (PV) panel. The estimate is provided by a current estimator that takes as input the output voltage of the PV panel as well as the bus voltage of the DC/DC converter. Also used as input to the current estimator are two of the control signals for specific power switches in the full bridge inverter in the DC/DC converter.

Abstract: Systems, methods, and devices for use in a DC/DC converter. A circuit uses a full-bridge power semiconductor subcircuit along with a high power transformer subcircuit, a diode bridge subcircuit, and a parallel capacitor to provide galvanic isolation and boost the voltage from a power source such as a photovoltaic panel. To ensure zero voltage switching for the power semiconductors, either a passive auxiliary subcircuit or an inductor coupled in parallel to a transformer in the transformer subcircuit may be used. A controller which derives its timing signals from the transformer primary current is used to control the timing of the power semiconductors in the circuit. The circuit and its controller allows for self-adjusting regardless of load and uses the entire switching cycle to be used for power transfer.

Abstract: A system includes a compressor that compresses incoming airflow, and a combustor assembly mixing the compressed incoming airflow with fuel and combusting the air and fuel mixture in a combustion zone. The combustor assembly includes a hot side downstream of the combustion zone and a cold side upstream of the combustion zone. The system also includes a turbine receiving products of combustion from the combustor. The combustor assembly includes a resonator positioned in the cold side of the combustor assembly in an annular passage between a flow sleeve and a casing of the combustor assembly.

Abstract: Systems, methods, and devices for use with active/reactive power control in power conditioning systems. To provide quick active/reactive power control by way of a grid-connected inverter, an estimator estimates the P and Q coefficients based on an instantaneous power from the grid-connected inverter. The estimator receives grid current and voltage and estimates of the P and Q coefficients are used with reference P and Q values to determine whether active or reactive power needs to be injected to the grid. The P coefficient is a DC offset of the instantaneous power of the grid and the Q coefficient is the coefficient of a sine component of the instantaneous power.

Abstract: Systems and devices relating to an integrated housing for microinverters. The housing has a cavity for housing the circuitry of the microinverter. The housing is mountable on a back sheet of a PV module by way of the housing's top cover. An opening at the back of the housing accommodates DC contacts coming from the PV module while a void configured for an output port is also present in the housing. When mounted on the PV module, the housing is spaced apart from the module.

Abstract: Systems, methods, and devices for use with photovoltaic micro-inverters. A control system for controlling power switches in a full bridge inverter in a DC/DC converter uses an estimate of the output current of a photovoltaic (PV) panel. The estimate is provided by a current estimator that takes as input the output voltage of the PV panel as well as the bus voltage of the DC/DC converter. Also used as input to the current estimator are two of the control signals for specific power switches in the full bridge inverter in the DC/DC converter.

Abstract: Systems, methods, and devices which estimate the inductor current in a power factor correction (PFC) converter for use with AC/DC converters. A control system for use with the PFC takes as input the input voltage and the output voltage of the PFC. Control signals for power semiconductor subcircuits in the PFC are then output from the control system. The control system uses an adaptive observer sub-circuit that estimates the inductor current and the bus voltage. The adaptive observer uses an adaptive updater which uses both the estimates and the estimate error to update the adaptive observer's estimates.

Abstract: Systems, methods, and devices related to controlling a DC/AC converter. A control system uses a nonlinear adaptive observer to estimate the state variables iinv and vC using a sensed grid current and a bus voltage as inputs. For non-observable points (such as when the duty cycle=0.5), the required information can be found from the DC bus voltage.

Abstract: A control approach of adjusting the input power of a power factor correction (PFC) stage so that the output voltage (DC-link) of the input AC/DC stage to an intermediate DC voltage (DC-Bus voltage) is adjusted based on the amount of power required to charge a high energy battery is disclosed. The present invention controls the input power of the PFC instead of the DC-bus voltage as is common in conventional methods. Therefore, a very fast response compared to the conventional sluggish voltage loop can be achieved. Also, having different DC-bus voltages for different output load conditions allows the DC/DC converter to work with an optimal duty cycle for a whole range of load variations.

Abstract: Systems, methods, and devices which eliminate the DC current from the output of grid-connected inverters. A current controller is provided which interfaces with a grid-connected DC/AC inverter. The current controller uses a nonlinear adaptive filter which receives, as input, the output current of the inverter along with grid current frequency. The nonlinear adaptive filter estimates the DC value of the grid current and, in conjunction with an integrator, removes this DC current component. This is done by adjusting the duty cycle of the grid-connected inverter.

Abstract: Systems, methods, and devices for controlling a DC-bus voltage for a power conditioning system. A control system regulates the DC value of the DC-bus voltage. The control system uses an adaptive DC-value estimator/observer to estimate this DC-value. Instead of having to determine the DC-value of a signal with a low frequency ripple without compromising the signal's dynamic response, a suitably precise estimate for that DC-value is used.

Abstract: Systems, methods, and devices which estimate the inductor current in a power factor correction (PFC) converter for use with AC/DC converters. A control system for use with the PFC takes as input the input voltage and the output voltage of the PFC. Control signals for power semiconductor subcircuits in the PFC are then output from the control system. The control system uses an adaptive observer sub-circuit that estimates the inductor current and the bus voltage. The adaptive observer uses an adaptive updater which uses both the estimates and the estimate error to update the adaptive observer's estimates.

Abstract: Systems, methods, and devices relating to DC/AC converters. A circuit including a full bridge inverter is provided. One leg of power semiconductor subcircuits of the inverter is switched at line frequency while the other leg is soft switched at a higher frequency using an auxiliary circuit. A control system is used to calculate this higher optimal frequency. To minimize the output current ripple in the output filter, the output inductor is coupled to the auxiliary inductor in the auxiliary circuit.

Abstract: Systems and methods relating to zero voltage switching for inverters. A full bridge inverter is used in conjunction with a passive auxiliary circuit and an output filter. A control system controls the current by way of the auxiliary circuit and injects a high quality current to a power grid. The control system adjusts the duty ratio and switching frequency of the gate pulses applied to the power semiconductors in the full-bridge inverter. As well, the control system adjusts the phase shift between gate pulses for both the leading leg and lagging leg power semiconductors to control the current passing through the auxiliary circuit.

Abstract: A system for the production of ammonium sulfate granules including a pipe cross reactor (PCR) configured to contact concentrated sulfuric acid with anhydrous ammonia to produce a PCR product comprising ammonium sulfate; and a granulator fluidly connected to the PCR, whereby PCR product extracted from the PCR can be introduced into the granulator, an inlet for ammonium sulfate seed material, an ammonia sparger configured to spray liquid anhydrous ammonia onto a bed of ammonium sulfate granules within the granulator, and a granulator product outlet configured for extraction of granulator product comprising ammonium sulfate granules from the granulator. A method of producing ammonium sulfate granules is also provided.

Abstract: Systems, methods, and devices relating to the use of multiple DC power generation sources with DC/DC converters to thereby provide AC power suitable for provision to a power grid. Multiple DC power generation sources are each coupled to an input stage with a DC/DC converter. All the DC/DC converters in the multiple input stages are controlled by a single digital controller. Within the single digital controller are controller sub-blocks, each of which generates control signals for a specific DC/DC converter. Each controller sub-block provides multiple functions for improving the performance of the system as a whole.

Abstract: Systems and devices relating to an integrated housing for microinverters. The housing has a cavity for housing the circuitry of the microinverter. The housing is mountable on a back sheet of a PV module by way of the housing's top cover. An opening at the back of the housing accommodates DC contacts coming from the PV module while a void configured for an output port is also present in the housing. When mounted on the PV module, the housing is spaced apart from the module.

Abstract: Provided are circuits and methods for a digital controller for an electronic ballast for a fluorescent lamp, comprising a feed-forward loop that provides information about a voltage firing angle, and a pulse width modulator that controls a duty ratio of at least one power switch of the electronic ballast according to the information. The digital controller may include a duty ratio controller implemented in the pulse width modulator. The digital controller may include one or more functions such as dimming, maintaining high power factor throughout the dimming range, low lamp power detection, lamp soft-start, and DC-link capacitor over-voltage detection for end of life protection or lamp failure protection. In one embodiment the ballast is a single stage, single switch ballast.

Abstract: Systems, methods, and devices for use in a DC/DC converter. A circuit uses a full-bridge power semiconductor subcircuit along with a high power transformer subcircuit, a diode bridge subcircuit, and a parallel capacitor to provide galvanic isolation and boost the voltage from a power source such as a photovoltaic panel. To ensure zero voltage switching for the power semiconductors, either a passive auxiliary subcircuit or an inductor coupled in parallel to a transformer in the transformer subcircuit may be used. A controller which derives its timing signals from the transformer primary current is used to control the timing of the power semiconductors in the circuit. The circuit and its controller allows for self-adjusting regardless of load and uses the entire switching cycle to be used for power transfer.

Abstract: A system for the production of ammonium sulfate granules including a pipe cross reactor (PCR) configured to contact concentrated sulfuric acid with anhydrous ammonia to produce a PCR product comprising ammonium sulfate; and a granulator fluidly connected to the PCR, whereby PCR product extracted from the PCR can be introduced into the granulator, an inlet for ammonium sulfate seed material, an ammonia sparger configured to spray liquid anhydrous ammonia directly onto a bed of ammonium sulfate granules within the granulator, a granulator vent configured for extraction of a vapor comprising unreacted ammonia from the granulator, and a granulator product outlet configured for extraction of granulator product comprising ammonium sulfate granules from the granulator. A method of producing ammonium sulfate granules is also provided.