Abstract: This application describes examples of a direct current combiner box, a photovoltaic power generation system, and a fault detection method. In one example, the direct current combiner box includes a fault detection unit, a protection circuit, and a boost circuit. The fault detection unit detects an operating parameter of the direct current combiner box. The protection circuit sends a protection signal to the boost circuit when the operating parameter meets a specified condition. The protection signal is used to enable the boost circuit to adjust a first voltage of a photovoltaic array at an input end of the direct current combiner box to a second voltage. After receiving the protection signal, the boost circuit adjusts the first voltage of the photovoltaic array at the input end of the direct current combiner box to the second voltage.

Abstract: A system to operate as a phase locked loop (PLL) includes a frequency synthesizer in a feedback path of the PLL and a delay line arranged to receive an output of the frequency synthesizer. A retimer subsystem is arranged to receive the output of the frequency synthesizer. A digitally controlled delay line (DCDL) is arranged to receive an output of the retimer. A phase detector is arranged to receive an output of the delay line and an output of the DCDL and to provide an error signal indicating a difference in phase of the output of the delay line relative to the output of the DCDL. A controller causes closed loop operation of the PLL during a normal operational mode and open loop operation during a calibration mode during which gain of the DCDL, defining a relationship between a control code and a resulting delay, is calibrated.

Abstract: Disclosed in the present invention is a crystal oscillator based on duty ratio measurement, comprising a first inverter, a resistor, a first load capacitor, a second load capacitor, first to fourth switches, a quartz crystal, a buffer, a sampling and holding module, a first comparator, a second comparator, a phase conversion module, a digital control module, and an energy injection module. One end of the quartz crystal is used for signal injection, a signal at the other end of the quartz crystal is sampled and processed, information representing phase error accumulation, i.e., a signal of which the duty ratio is continuously changing, is obtained by means of the first comparator, and finally the duty ratio is measured by means of the phase conversion module and the second comparator, so as to obtain an accurate moment of phase switching.

Abstract: A control system providing a control signal to an energy storage system to reduce power variability of an energy generation system. The energy storage system is coupled to the power output of the energy generation system and configured to at least one of receive and provide electrical power in response to the control signal. The control system includes a monitoring unit to monitor the power output and to provide a respective monitoring signal. The control system further includes a control signal generation unit to generate the control signal from the monitoring signal, and implement a filtering unit that has a band pass response. The filtering unit passes a predetermined frequency band of the monitoring signal and the control signal generation unit is configured to generate the control signal in the frequency band to compensate power variations of the power output of the energy generation system in the frequency band.

Abstract: An apparatus includes at least one first circuit configured to generate a first time-varying magnetic field for magnetic induction power transfer to a device, at least one second circuit configured to generate and/or receive a second time-varying magnetic field for magnetic induction data transfer to and/or from the device, and at least one third circuit configured to generate a third time-varying magnetic field in response to a time-varying electric current. The third time-varying magnetic field is configured to at least partially inhibit degradation of said data transfer from the first time-varying magnetic field. The apparatus further includes at least one fourth circuit configured to generate the time-varying electric current in response to a received portion of the first time-varying magnetic field.

Abstract: A wireless power transmission apparatus according to an embodiment of the present specification transmits wireless power to a wireless power reception apparatus and comprises: a power conversion circuit that transmits the wireless power to the wireless power reception apparatus; and a communication/control circuit that communicates with the wireless power reception apparatus and controls the wireless power. In a power transfer phase for transmitting the wireless power to the wireless power reception apparatus, the communication/control circuit may receive, from the wireless power reception apparatus, a data packet including information about a slot time for performing foreign object detection and perform the foreign object detection during the slot time.

Abstract: Provided is a monitoring device for monitoring a control signal received by a power converter, the control signal controlling switches to supply an electrical load. The monitoring device includes a receiving circuit that receives the control signal comprising a merging of a first variable signal and a clock signal having a predetermined frequency greater than the first variable signal, a determining circuit that determines if a change of state of the control signal occurs during each period associated to the predetermined frequency, and a monitoring circuit that stops the transmission of the control signal to the power converter so that the power converter stops to supply the electrical load according to the instructions of the first variable signal if a change of state of the control signal does not occur during one period.

Abstract: A method and apparatus for generating electrical power, including providing a generator configured to generate a first voltage, providing a voltage converter configured to operably down-convert the first voltage output to a second voltage output to provide a first amount of power to a set of electrical loads, and changing a power demand for at least a subset of the set of electrical loads, wherein the changed power demand increases the power demanded. To meet the increased power demand, the voltage converter is controlled to operably down-convert the first voltage output to the second voltage output to provide a second amount of power to the set of electrical loads. The second amount of power is greater than the first amount of power. The power-generating capabilities of the generator are not modified between providing the first amount of power and providing the second amount of power.

Abstract: Aspects of a storage device including a memory and a controller are provided. In certain aspects, the storage device may include a holdup circuit powered and controlled by the controller. In some examples, the holdup circuit may be configured to charge a first capacitor by closing a first switch coupled between the first capacitor and a boost converter during a first window of time. The holdup circuit may also be configured to charge a second capacitor by closing a second switch coupled between the second capacitor and the boost converter during a second window of time.

Abstract: An atomic clock system includes a waveguide cavity that is sealed and comprises a gas enclosed therein. The waveguide cavity has a length that is an integer multiple of approximately one half-wavelength of a resonant frequency of the gas between two states. An oscillator system generates an RF signal through the waveguide cavity. The RF signal has a signal frequency that is approximately equal to the resonant frequency of the gas. A detection system measures a characteristic of the RF signal through the waveguide cavity to detect a maximum transition between the two states of the gas and to provide a feedback signal to the oscillator system to lock the signal frequency of the RF signal to the resonant frequency of the gas based on detecting the maximum transition. The detection system provides a frequency reference output signal based on the signal frequency of the RF signal.

Abstract: An energy storage system comprises a set of swappable battery modules positioned in battery slots with a battery module being controlled by a control switch. The control switches are linkable to form a charging control chain and/or a discharging control chain respectively to control sequential charging/discharging, parallel charging/discharging, and segmented charging/discharging among the set of battery modules in the energy storage system. Methods to detect defective battery module in a battery slot are also presented. The energy storage system can be configured in an AC power distribution environment, a DC power distribution environment, or in an EV. The energy storage system is scalable, automatically reconfigurable and accepts AC power and regenerated DC power.

Abstract: An oscillator and method for maintaining a phase lock is provided. The oscillator may include an oscillator input port for receiving a reference signal, an oscillator output port for outputting an oscillator output, an unlocked oscillator oscillating in an unlocked state and outputting at a resonance frequency configured to drift in response to changes in an operating environment, and a phase locked loop (PLL) including a mixer having an output port configured to output the unlocked oscillator output mixed with a local oscillator output, the mixer output port in communication with a phase frequency detector and the oscillator output port, and the phase frequency detector generating a control signal based on a detected phase difference between the reference signal and the mixer output wherein the control signal adjusts the local oscillator output to compensate for the resonance frequency drift of the unlocked oscillator when mixed with the unlocked oscillator output.

Abstract: A rubidium optical atomic clock uses a modulated 778 nanometer (nm) probe beam and its reflection to excite rubidium 87 atoms, some of which emit 758.8 nm fluorescence as they decay back to the ground state. A spectral filter rejects scatter of the 778 nm probe beams while transmitting the 775.8 nm fluorescence so that the latter can be detected with a high signal-to-noise ratio. Since the spectral filter is only acceptably effective at angles of incidence less than 8° from the perpendicular, the atoms are localized by a magneto-optical trap so that most of the atoms lie within a conical volume defined by the 8° angle so that the resulting fluorescence detection signal has a high signal-to-noise ratio. The fluorescence detection signal can be demodulated to provide an error signal from which desired adjustments to the oscillator frequency can be calculated.

Abstract: A low power crystal oscillator circuit has a high power part and a low power part. Crystal oscillation is initialized using the high power part. An automatic amplitude control circuit includes a current subtractor that decreases current in the high power part as an amplitude of the crystal oscillation increases. A current limiting circuit may limit current in the low power part in order to further reduce power consumption by the low power crystal oscillator circuit. Additionally, an automatic amplitude detection circuit may turn off the high power part after the amplitude of the crystal oscillation reaches a predetermined level in order to further reduce power consumption of the low power crystal oscillator circuit, and may turn back on the high power part after the amplitude of the crystal oscillation reaches a second predetermined level in order to maintain the crystal oscillation.

Abstract: A structure is a structure of a quartz crystal substrate having a slit. The structure includes, as an inner wall of the slit, a first side surface, a second side surface, a first end surface, and a second end surface. The first side surface extends along a first direction which is a longitudinal direction of the slit, and the second side surface extends along the first direction. The first end surface is continuous with the first side surface and extends along a first crystal plane of the quartz crystal substrate, and the second end surface is continuous with the second side surface and extends along a second crystal plane of the quartz crystal substrate. In a plan view of the quartz crystal substrate, an intersection point where a first straight line corresponding to the first end surface and a second straight line corresponding to the second end surface intersect each other is located inside the quartz crystal substrate.

Abstract: An injection-locked oscillator includes a plurality of delay elements, two or more voltage control circuits, a phase comparator and a controller. The plurality of delay elements is connected in a loop and coupled to a global power supply. Each delay element has an input driven by a preceding stage and an output that drives a next stage. Each voltage control circuit couples one of the plurality of delay elements to the global power supply. The phase comparator is coupled to in-phase and quadrature outputs of the injection-locked oscillator. The controller is coupled to an output of the phase comparator and is configured to drive control inputs of the two or more voltage control circuits. The control input of each voltage control circuit determines a level of a voltage drop across the each voltage control circuit.

Abstract: A control switch incorporating a 1:2 demultiplexer is used to control timing for a concurrent switching, break-before-make and make-before-break power multiplexing, and is configurable to link a plurality of the control switches into a control chain to perform sequential charging, sequential discharging, parallel charging, parallel discharging, and concurrent sequential charging and discharging for a plurality of batteries coupled to the control chain in a power system.

Abstract: New wireless power distribution and payment techniques are disclosed. In some aspects of the invention, a system distributes wireless power through a network of wireless power transmission devices, which may be independently owned and controlled. The system may create monetary payments and charges based on each device's use and/or facilitation of the wireless power provided through the network, and incentives required to increase performance of the system. In some embodiments, the system may determine monetary credits and/or debits based on the type and amount of power provided by, or other qualities of, wireless power enhancement devices implemented by the network, and users thereof. For example, in some embodiments, the system determines a rating (e.g., based on efficiency or superiority of the power source) of at least one of wireless power transmission devices. Such ratings may be determined by consensus, and recorded, on a distributed ledger, such as a blockchain.

Abstract: A method of controlling a frequency-modulated oscillator 110 of a phase-locked loop circuit 100 is described, wherein the oscillator 110 comprises a bank of capacitors 413. The method comprises the steps of (i) switching a capacitor 414 of the bank of capacitors 413 to change an output frequency 1050 of an output signal 112 of the oscillator 110 from a first frequency 1051 to a second frequency 1052, (ii) determining a frequency information associated with the capacitor 414 and based on at least one of the first frequency 1051 and the second frequency 1052; and (iii) writing the frequency information to a look-up table 224, 225, 226 stored in a control unit 120 of the oscillator 110. A corresponding frequency-modulated oscillator 110 and phase-locked loop circuit 100 are also described.

Abstract: A method for compensating for frequency shifts caused by variation in an environmental parameter of an atomic clock is provided. A preset reference voltage of a proportional integral differential amplifier is set so that an offset frequency shift is generated in locking frequency of a laser. Then, the preset reference voltage is optimized by correcting the frequency shift coefficient to obtain an optimal reference voltage. A non-peak point of the resonance spectral line of the atomic clock is locked, so that the variation in the offset frequency shift caused by power variation of an optical signal output by the laser can compensate for the variation in the locking frequency of the laser caused by the power variation, thereby reducing the frequency shift coefficient caused by the power variation. The method is simple to operate and has universality.