Abstract: A circuit protection method, system, and apparatus are provided. The method includes: receiving a current between an output terminal of the inverter circuit and a power grid; determining, based on the current, whether a current abnormality occurs; and controlling to switch off switch transistors in the inverter circuit, on determining that a current abnormality occurs.

Abstract: Inwardly opposed piston, compression ignition engines are quiet, compact in size, and reliable.

Abstract: A device such as a smart thermostat is provided for controlling heating and cooling systems. The device is operable to execute an energy control program to control the heating and a cooling systems based upon different control strategies: a first control strategy that compares the at least one temperature setpoint in the programming schedule to the current measured dry bulb temperature to determine whether to engage or disengage the heating and a cooling systems, and a second control strategy that compares the at least one temperature setpoint in the programming schedule to a normalized humidex temperature to determine whether to engage or disengage the heating and a cooling systems, the normalized humidex temperature being the current measured dry bulb temperature modified by historical humidity values to provide an indicator of thermal comfort within the premise.

Abstract: A rotor core lamination is provided. The rotor core lamination includes a plurality of salient poles. Each of the salient poles includes: a pole body having a central axis in a radial direction of the rotor core lamination; and a pole shoe extending radially outward from the pole body, wherein the pole shoe has a pole shoe arc, and a central point of the pole shoe arc is offset from the central axis.

Abstract: A method of setting a synchronous rectifier on-time value includes determining that a time interval has occurred, receiving a number of triangular current mode (TCM) pulses measured during the time interval, and determining a pulse comparison value equal to a number of switching period pulses during the time interval minus the number of TCM pulses during the time interval. The method also includes increasing the synchronous rectifier on-time if the pulse comparison value is greater than or equal to a threshold and decreasing the synchronous rectifier on-time if the pulse comparison value is less than the threshold.

Abstract: A power supply system and a solar photovoltaic inverter, a DC/DC module and a rectification module. Since a power supply outputted from a solar panel is low-voltage power, the power supply at an output end of the solar panel can be directly supplied to a DC driving module and a DC side circuit. Since a power supply outputted from a main transformer is high-voltage power, the AC outputted from the main transformer can be directly supplied to an inverter driving module, a rectification driving module, and an AC side circuit, without additionally providing an auxiliary power supply for high-voltage isolation, namely, without additionally providing a switching circuit, a transformer, a second rectifier module, and a third rectifier module, thereby avoiding the noise and power consumption caused by frequent ON or OFF of the switching circuit, and reducing the cost.

Abstract: An electric system has an input terminal to receive an input voltage, a system output terminal to provide a system voltage, and N charging units for charging N loads respectively. The electric system has an input switch coupled between the input terminal and a first terminal, a switching circuit coupled between the first terminal and the system output terminal. The switching circuit converts the a boost output voltage at the first terminal to the system voltage, or converts the system voltage to the boost output voltage. The electric system further has a voltage control module having N input terminals coupled to the N charging units respectively, the voltage control module senses N charging currents passing through the N charging units respectively, and adjusts the boost output voltage based on the N charging currents.

Abstract: A rollable ribbon separator tool for separating fibers in a rollable ribbon, the rollable ribbon separator including a chassis having a length and a guide surface along the chassis length for receiving a first portion of a rollable ribbon in a flattened position, the guide surface for positioning the first portion of the rollable ribbon having a first node with selected fibers to be separated, the selected fibers being positioned flat on the guide surface. The rollable ribbon separator includes a blade securable to the chassis, the blade having a cutting edge positioned toward the guide surface at an acute angle to the guide surface. The angle of the blade cutting edge with respect to the guide surface allows the cutting edge to urge the first portion of the flattened ribbon fibers against the guide surface when the fibers are drawn through the chassis along the guide surface.

Abstract: Methods and apparatus to monitor the precharging of high voltage circuits are disclosed. In one embodiment, an apparatus includes a switch that selectively enables or disables precharge current to a high voltage circuit based on a switch control signal. The apparatus also includes a comparison circuit that compares a scaled version of a circuit voltage to a reference voltage to generate the switch control signal. In one embodiment, the switch control signal is generated to enable the precharge current when the scaled version of the circuit voltage is greater than the reference voltage.

Abstract: A mobile pressure washer can include a wheeled chassis, a power plant supported by the wheeled chassis, a fluid pump a fluid pump coupled to and driven by the power plant, a sprayer in fluid communication with the pump, a chemical solution container, and a container holder for supporting the chemical solution container. In some examples, the container holder has a frame operably connected to the wheeled chassis and has a container support mounted to the frame, the container support including a base wall and a sidewall defining a receptacle for receiving and supporting a container in fluid communication with the pump.

Abstract: A network access credential change request is received onto a network access credential updating system. The network access credential change request is a request to update access credentials of a network near a vehicle charge station. The new credential in the request is communicated to an electric vehicle. The network is updated with the network access credential. The vehicle is able to connect to the network with the updated credential after the network has been updated. In one embodiment, the network access credential updating system includes an application. A charge station operating entity communicates a network access credential change request for a particular network to the application. After sending the request, the charge station operating entity updates the network access credential for the network in accordance with a credential update agreement. The credential update agreement tends to afford adequate opportunity for vehicles to receive updated credentials before networks are updated.

Abstract: A module switchoff device and a security protection system of a photovoltaic power generation system.

Abstract: An apparatus for controlling a power converter includes a controller configured to detect an error in an output voltage of the power converter at a zero-crossing of a cyclically varying input signal and a compensator coupled to the controller and the power converter and configured to regulate the output voltage of the power converter in response to the error.

Abstract: An uninterruptible power system and an operation method thereof are provided. The uninterruptible power system comprises a DC-AC conversion circuit, a plurality of switches, a plurality of sensing units, a plurality of output ports and a control unit. Each output port is electrically coupled to an output terminal of the DC-AC conversion circuit sequentially through one of the sensing units and one of the switches. The control unit is configured to define members of at least one group from the output ports according to a system setting, and define which members of each group are non-critical output ports according to the system setting. The control unit is further configured to set, according to the system setting, at least one condition for all non-critical output ports in each group to simultaneously stop supplying power, and to accordingly control the operations of the corresponding switches.

Abstract: An eFuse for use in high voltage applications is disclosed. In one embodiment, an apparatus includes a solid-state switch having source and drain terminals connected to switch a load current from a high voltage source through a high voltage load. The apparatus also includes a sense circuit that senses a voltage between the switch source and drain terminals and turns off the switch when the voltage exceeds a selected voltage level.

Abstract: Junction field effect transistors (JFETs) and related manufacturing methods are disclosed herein. A disclosed JFET includes a vertical channel region located in a mesa and a first channel control region located on a first side of the mesa. The first channel control region is at least one of a gate region and a first base region. The JFET also includes a second base region located on a second side of the mesa and extending through the mesa to contact the vertical channel region. The vertical channel can be an implanted vertical channel. The vertical channel can be asymmetrically located in the mesa towards the first side of the mesa.

Abstract: A transistor includes a III-nitride substrate, a first III-nitride layer on the III-nitride substrate, wherein the first III-nitride layer is characterized by a first conductivity type, and a plurality of III-nitride fins on the first III-nitride layer, wherein each of the plurality of III-nitride fins is separated by one of a plurality of first recess regions and characterized by a fin surface, wherein the plurality of III-nitride fins are characterized by the first conductivity type. The transistor also includes a III-nitride gate layer having a second conductivity type opposite to the first conductivity type in the plurality of first recess regions, wherein a surface of the III-nitride gate layer is substantially coplanar with the fin surface, and a regrown III-nitride source contact portion coupled to each of the plurality of III-nitride fins, wherein the regrown III-nitride source contact portion is characterized by the first conductivity type.

Abstract: A vapor-compression multi-evaporator cooling system comprises a cooling control system and two or more evaporators each coupled to an expansion valve. Each evaporator is selectively enabled or disabled during operation. When an evaporator is enabled, the evaporator transfers heat into a working fluid within the system. When an evaporator is disabled, the evaporator does not exchange any appreciable amount of heat within the system. The cooling control system includes a cooling controller, an adjustable compressor, a condenser, and a variable speed fan that provides selectable amounts of cooling to the condenser. During operation, the cooling controller adjusts the compressor operation and fan speed to maintain stable operation of the cooling system. To compensate for enabling or disabling of evaporators, the cooling controller adjusts compressor operation and fan speed to provide more or less compression and more or less condenser cooling to maintain stable and efficient operation of the cooling system.

Abstract: A fuel cell power plant includes an energy storage system connected in parallel with a fuel cell system. The fuel cell system includes a controller, a fuel flow system, an air flow system, and an internal water management system. The controller is operable to receive, as inputs, the energy storage system state of charge and the power demand from an electric load. The controller is further operable to determine a power split set point and execute commands, as output, to control operation of the air flow system, wherein the air flow system actively regulates the proportion of current flow between the fuel cell system and the energy storage system to meet the power demand of the electric load.