7086 results about "Bus voltage" patented technology

A method of controlling a motorized window treatment provides for continued operation of the motorized window treatment during an overload or low-line condition. The motorized window treatment is driven by an electronic drive unit having a motor, a motor drive circuit, and a controller. The controller controls the motor drive circuit to drive the motor with a pulse-width modulated signal generated from a bus voltage. The controller is operable to monitor the magnitude of the bus voltage. If the bus voltage drops below a first voltage threshold, the controller stops the motor or reduces the duty cycle of the pulse-width modulated signal to allow the bus voltage to increase to an acceptable magnitude. When the bus voltage rises above a second voltage threshold, the controller begins driving the motor normally once again. During an overload or low-line condition, the controller is prevented from resetting, while driving the motor with minimal interruption to the movement of the motorized window treatment.

A light-emitting diode (LED) driver is adapted to control either the magnitude of the current conducted through a LED light source or the magnitude of a voltage generated across the LED light source. 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 the magnitude of the current conducted through 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. The LED drive circuit may comprise a controllable-impedance circuit, such as a linear regulator. The LED driver may be operable to control the magnitude of the bus voltage to optimize the efficiency and reduce the power dissipation in the LED drive circuit, as well ensuring that the load voltage and current do not have any ripple.

A power and control architecture employing circuitry that sequentially regulate power flows from independent solar-array sources or a mixture of power sources providing power to a common load. The device may be used on a satellite with solar-array sources; however it may also be used on ground based systems. Stiff bus voltage regulation is obtained by tightly controlling the most recently activated power-processing channel while keeping the previously activated power-processing channels in the Maximum Power Tracking mode to supply maximum power to a common load. The remaining power-processing channels are turned off or operated in stand-by mode. In an alternative system, with primary design goal of uniform power sharing among solar-array sources, all solar array sources are activated with uniform power sharing at light load and, as load demand increases, sequentially controlled to operate in the Maximum Power Tracking mode one solar array source at a time as necessary.

A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system. A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

An LED driver for controlling the intensity of an LED light source includes a power converter circuit for generating a DC bus voltage, an LED drive circuit for receiving the bus voltage and controlling a load current through, and thus the intensity of, the LED light source, and a controller operatively coupled to the power converter circuit and the LED drive circuit. The LED drive circuit comprises a controllable-impedance circuit adapted to be coupled in series with the LED light source. The controller adjusts the magnitude of the bus voltage to a target bus voltage and generates a drive signal for controlling the controllable-impedance circuit. To adjust the intensity of the LED light source, the controller controls both the magnitude of the load current and the magnitude of the regulator voltage. The controller controls the magnitude of the regulator voltage by simultaneously maintaining the magnitude of the drive signal constant and adjusting the target bus voltage.

A two-stage power converter that dynamically adjusts to output current requirements includes a first stage regulator that provides power to a second stage regulator. The first stage can be a buck converter, and the second stage can be a multiple-phase buck converter. The output voltage of the first stage (intermediate bus voltage Vbus) is varied according to the load current to optimize conversion efficiency. To provide maximum efficiency, the Vbus voltage is increased as load current increases. The Vbus voltage provided by the first stage can be varied by duty cycle or operating frequency control. In another embodiment, the switching frequency of the second stage is varied as output current changes so that output current ripple is held constant. In an embodiment employing a multiple-phase buck converter in the second stage, the number of operating phases are varied as output current changes.

The present invention provides a universal serial bus (USB) voltage transformer, which comprises a main body, a transformer circuit unit, and several connectors. The transformer circuit unit is disposed in or at the inside of the main body. The connectors are electrically connected to the transformer circuit unit directly or via a connection cable. A USB voltage transformer having travel charging function is thus formed. The USB voltage transformer of the present invention can simultaneously charge several portable electronic devices like mobile phones, personal digital assistants, electronic translators, and small cameras.

The invention relates to a super capacitor energy storage type power quality compensator. A system structure comprises a compensation transformer, a series compensator, a parallel compensator, a super capacitor group, a current foldback circuit, a bidirectional DC / DC chopper circuit, a signal sampling circuit, a control circuit, a drive circuit, a human-computer interface and corresponding auxiliary circuits, which form a three-phase three-wire system topological structure. By utilizing the excellent characteristics of great power density, high charging and discharging speed and long cycle life of a super capacitor, the super capacitor energy storage type power quality compensator is matched with the DC / DC chopper circuit to form an energy storage control system which plays the roles of adjusting power and stabilizing the voltage of a direct current bus in work. The invention also has the functions of dynamic voltage recovery, active filter and reactive compensation and can ensure that a load can obtain rated sine voltage and the current of a grid is sine current with the same direction (unit power factor) with that of a voltage fundamental wave positive sequence active component, thereby comprehensively improving the quality of power. The invention has positive generalization and application value for both the public grid and users.

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.

An LED driver for controlling the intensity of an LED light source includes a power converter circuit for generating a DC bus voltage, an LED drive circuit for receiving the bus voltage and controlling a load current through, and thus the intensity of, the LED light source, and a controller operatively coupled to the power converter circuit and the LED drive circuit. The LED drive circuit comprises a controllable-impedance circuit coupled in series with the LED light source. The controller adjusts the magnitude of the bus voltage to a target bus voltage and generates a drive signal for controlling the controllable-impedance circuit. To adjust the intensity of the LED light source, the controller controls the magnitudes of both the load current and the regulator voltage. The controller controls the magnitude of the regulator voltage by simultaneously maintaining the magnitude of the drive signal constant and adjusting the target bus voltage.

A device, a system, and a method for preventing power-producing wind turbine generators from tripping due to the detection of a low-voltage condition on a power grid are disclosed. The disclosed device includes a resistor bank that absorbs real power and a control system that maintains the collector bus voltage above a threshold voltage level during the duration of low-voltage condition on the power grid. Collector bus voltage is maintained using gating signals that include phase delay angles to adjust the opening / closing of the switching devices.

The invention relates to the technical field of photovoltaic micro-grid control, and particularly discloses a real-time coordination and control method of a photovoltaic micro-grid system. A central real-time optimal control layer and a local control layer are involved in the real-time coordination and control method. The central real-time optimal control layer collects the voltage and frequency of an AC bus of the photovoltaic micro-grid system, the charge state of a storage battery pack, the output power of photovoltaic power generation micro-sources, the output power of the storage battery pack, the output power of a super capacitor and the real-time power of a load in real time, generates a real-time coordination and control strategy and a secondary frequency modulation and scheduling plan, and issues the strategy and the plan to all local controllers. The local control layer coordinates and controls all the micro-sources in real time, and particularly achieves the scheduling plan issued by the central real-time optimal control layer. According to the real-time coordination and control method, a micro-grid central optimizing controller can manage, coordinate and control all the local controllers in a unified mode, the micro-grid can efficiently and economically run, the output power of the photovoltaic power generation unit is utilized to the maximum extent, the output power fluctuation and the tracking load change of the photovoltaic power generation unit are restrained, the running method of the micro-grid is reasonably adjusted, and energy balance is achieved.

The present invention discloses a high efficiency constant current LED driver, which comprises a rectification bridge, a PFC main circuit, an isolated DC / DC converter, a PFC controller and a PFC bus control circuit. Since the input voltage is an intermediate PFC bus voltage, which varies with the output voltage of the DC / DC converter. When the isolated DC / DC converter is an LLC resonant circuit, the operating frequency of the LLC circuit is close to the resonant frequency within a wide output voltage range. Thus, the gain range and the operating frequency is narrow, and can enable the constant current module to work with a high efficiency at a wide output voltage range. When the isolated DC / DC converter is a symmetric half bridge, or an asymmetric half bridge or a full bridge circuit, the duty cycle of DC / DC circuit is close to 50% within a wide output voltage range. Thus, the changing range of the duty cycle of the DC / DC converter will be narrow and can improve the efficiency dramatically.

A power redundant power system and a method for controlling the power system are presented, wherein the power system is composed of at least one inverter for supplying AC power to a load through a bus, a phase lock system to synchronize all output voltages of the inverters and a current sharing circuit to properly distribute the load current among all inverters. Each inverter is controlled by an unbalanced power to limit the increase of its cross current. Moreover, the information related to DC bus voltage is further applied to control the inverters, whereby the cross current is mitigated and entire power system is operated steadily.

A door position control including an electric door actuator having a motor and a motor controller in communication with a system controller. A motor actuation operation is selected from a plurality of predetermined motor actuation operations to provide control signals to the motor controller for controlling actuation of the motor for control of door movement. Control of door movement is effected with reference to parameters specific to an installation location including an angular sweep of the door between open and closed positions and with reference to an available bus voltage for supplying power to the motor.

The power unit includes H bridge inverter circuit, capacitance in DC section connected to DC bus in inverter circuit, and control circuit for controlling operation of the power unit. The power unit also includes a clipping energy consumption circuit. Combining a small quantity of active power absorbed by active electric power filter, the method realizes controlling DC bus voltage of power unit. The active electric power filter includes following parts: inverter with each phase including at least one power unit; voltage detection circuit, central control system, filtering circuit, precharge circuit, income line switch, interface and communication circuit, and cooling unit etc.

A stabilized electric distribution system for use in a vehicle having electric assist. The system electrically couples an electric assist bus to an accessory load bus while protecting the first electrical bus from electric assist and regenerative braking induced voltage variations. An energy management controller selectively controls each of a electric motor / generator, a DC / DC converter, and an alternator to affect electric energy distribution within the system. Preferably, the electric energy distribution is controlled to maintain the first electrical bus voltage within a predefined voltage range.

A system and method for controlling a permanent magnet motor are disclosed. Briefly described, one embodiment receives a torque command and a flux command; receives information corresponding to a direct current (DC) bus voltage and a motor speed; computationally determines feedforward direct-axis current information and feedforward quadrature-axis current information from a plurality of parameters associated with the permanent magnet motor; determines a current signal (idq*) based upon at least the requested torque command, the flux command, the DC bus voltage, the motor speed, the feedforward direct-axis current information, and the feedforward quadrature-axis current information; and controls a power inverter that converts DC power into alternating current (AC) power that is supplied to the permanent magnet motor, such that the permanent magnet motor is operated in accordance with the determined idq*.

A load control device for controlling the amount of power delivered to an electrical load may include a rectifier circuit configured to receive a phase-control voltage and produce a rectified voltage. A power converter may be configured to receive the rectified voltage at an input and generate a bus voltage. An input capacitor may be coupled across the input of the power converter. The input capacitor may be adapted to charge when the magnitude of the phase control voltage is approximately zero volts. The power converter may be configured to operate in a boost mode, such that the magnitude of the bus voltage is greater than a peak magnitude of the input voltage. The power converter may be configured to operate in a buck mode to charge the input capacitor from the bus voltage when the magnitude of the phase-control voltage is approximately zero volts.

A two-stage power converter that dynamically adjusts to output current requirements includes a first stage regulator that provides power to a second stage regulator. The first stage can be a buck converter, and the second stage can be a multiple-phase buck converter. The output voltage of the first stage (intermediate bus voltage Vbus) is varied according to the load current to optimize conversion efficiency. To provide maximum efficiency, the Vbus voltage is increased as load current increases. The Vbus voltage provided by the first stage can be varied by duty cycle or operating frequency control. In another embodiment, the switching frequency of the second stage is varied as output current changes so that output current ripple is held constant. In an embodiment employing a multiple-phase buck converter in the second stage, the number of operating phases are varied as output current changes.

The invention relates to an emergency protection circuit device capable of completing automatic switching when an AC-DC power grid is in an abnormal state, and in particular relates to an intelligent warning and control method dedicated for ensuring safety and stability of the power grid. The method comprises the steps that: an intelligent control master station acquires real-time data of the power grid through an EMS (energy management system), and an intelligent control substation in each zone real-timely monitors the bus voltage of the zone, power-receiving channel overload, main transformer overload in the zone and voltage instability of the power grid in the zone, and starts the power grid safety and stability control operation; the acquired real-time data of the power grid is integrated with the information uploaded by each substation to real-timely form tide section data of the power grid, and the safety and stability of the power grid are evaluated online; and safety and stability early-warning information of the power grid is provided by using the real-time operation data of the power grid to realize safe and stable control of the power grid and to realize the function of the second line of defense of the power system. The method provided by the invention can ensure safe and stable operation of the power grid by regulating a stability control device according to the running condition of the power grid.

The invention discloses an intelligent solar cell component and a control method of an array thereof. An intelligent power electronic converter in which a microprocessor serves as a control core is arranged at a junction box of the traditional solar cell component and has a data communication function; system information such as a direct current (DC) bus voltage of a photovoltaic system, the maximal output power of other components in the same serial string and the like can be acquired through the communication function; the system information acquired through the communication function is higher than that of the maximal power point of the component; and the output voltage and the output current are automatically adjusted by a power weight matching method, so that the output energy of the component is maximized. By the method, each component can output the maximal electric energy.

The utility model relates to a digitized high voltage direct current power supply, and comprises a main power circuit, a digitized control circuit based on DSP and a control program of host computer based on PC, wherein the main power circuit comprises a three phase rectifying element [1], a soft start element [2], a filter element [3], a resonance inverting element [4], a high frequency and high voltage transformer [5], a doubling circuit [6] and a two-stage voltage divider [7]; the digitized control circuit based on DSP comprises an interface circuit of IPM drive signal, a high voltage feedback element, a resonance overcurrent protection element, a soft start circuit and a serial communication interface circuit. The voltage of power frequency electrical network is converted into DC voltage which is used as busbar voltage by three phase rectification, soft start and filter, and the busbar voltage is converted into 20KHz quasi-sine-wave by the resonance inverting element which is driven by a phase difference computed by the DSP according to feedback signal, and then 0-100Kv AC high voltage is output by the high frequency and high voltage transformer [5] and the doubling circuit [6]. The utility model adopts a host computer as a control device, and outputs the voltage via the control instructions of the DSP, therefore meets the requirements of voltage withstand test of insulation material.

The invention relates to a vehicle-mounted fuel cell and storage cell directly paralleled power system with a super capacitor. The power system comprises a fuel cell galvanic pile, a fuel cell accessory system, a fuel cell controller, a storage battery group, a super capacitor group, a high voltage bidirectional DC / DC (direct current) converter, a small power unidirectional DC / DC converter, a motor controller, a driving motor and a system energy management controller, wherein a high voltage output end of the fuel cell galvanic pile is connected with an anode of a power diode through a high voltage switch K1, and the high voltage output end of the storage battery group is directly connected with a cathode of the power diode and the high voltage output end of the motor controller in parallel through a high voltage switch K2 to form a direct current bus. The super capacitor group is connected with the direct current bus through the high voltage bidirectional DC / DC converter, and the high voltage output end of the storage battery group is connected with the fuel cell accessory system through the small power unidirectional DC / DC converter. According to the system disclosed by the invention, a power supply mode in which galvanic pile output needs large power DC / DC voltage stabilization of a conventional fuel cell is abandoned, and the efficiency is improved; the instantaneous needed power of the direct current bus can be compensated by the arranged super capacitor group, the bus voltage is steadied, and braking energy can be quickly and effectively recycled.

A converter unit configured to couple to a photovoltaic panel (PV) may include a controller to sense an output voltage and output current produced by the photovoltaic panel, and manage the output voltage of a corresponding power converter coupled to a DC bus to regulate the resultant bus voltage to a point that reduces overall system losses, and removes non-idealities when the panels are series connected. The controller may also adapt to output condition constraints, and perform a combination of input voltage and output voltage management and regulation, including maximum power point tracking (MPPT) for the PV. The output voltage and output current characteristic of the power converter may be shaped to present a power gradient—which may be hysteretically controlled—to the DC bus to compel an inverter coupled to the DC bus to perform its own MPPT to hold the DC-bus voltage within a determinate desired operating range.

A system and method for controlling a permanent magnet motor are disclosed. Briefly described, one embodiment receives a torque command and a flux command; receives information corresponding to a direct current (DC) bus voltage and a motor speed; computationally determines feedforward direct-axis current information and feedforward quadrature-axis current information from a plurality of parameters associated with the permanent magnet motor; determines a current signal (idq*) based upon at least the requested torque command, the flux command, the DC bus voltage, the motor speed, the feedforward direct-axis current information, and the feedforward quadrature-axis current information; and controls a power inverter that converts DC power into alternating current (AC) power that is supplied to the permanent magnet motor, such that the permanent magnet motor is operated in accordance with the determined idq*.

A power converter uses a control method to optimize efficiency by dynamically optimizing a controlled parameter. A change in efficiency of the converter after changing at least one controlled parameter is determined. The direction of change in efficiency of the converter is compared to a direction of the change in the controlled parameter. The controlled parameter is changed in a positive direction when the direction in the change in the efficiency of the converter and the direction of the change in the controlled parameter are the same and changed in a negative direction when the direction in the change in the efficiency of the converter and the direction of the change in the controlled parameter are opposite. The controlled parameters may include dead time between turn-on and turn-off and between turn-off and turn-on of the primary and corresponding secondary side switches of the controller, drive voltage(s) for the switches, and intermediate bus voltages.

A stabilized electric distribution system for use in a vehicle having electric assist. The system electrically couples an electric assist bus to an accessory load bus while protecting the first electrical bus from electric assist and regenerative braking induced voltage variations. An energy management controller selectively controls each of a electric motor / generator, a DC / DC converter, and an alternator to affect electric energy distribution within the system. Preferably, the electric energy distribution is controlled to maintain the first electrical bus voltage within a predefined voltage range.

A method for pulse width modulated pulse synchronization in a parallel UPS system uses the locally measured critical bus voltage to detect a zero crossing and adjust the PWM pulse to coincide with the zero crossing. No communication between the units is required to perform synchronization, and no “master” and “slave” relationship exists to thereby increase the total system reliability.

A device, a system, and a method for preventing power-producing wind turbine generators from tripping due to the detection of a low-voltage condition on a power grid are disclosed. The disclosed device includes a resistor bank that absorbs real power and a control system that maintains the collector bus voltage above a threshold voltage level during the duration of low-voltage condition on the power grid. Collector bus voltage is maintained using gating signals that include phase delay angles to adjust the opening / closing of the switching devices.