2542 results about "Capacitance voltage" patented technology

Embodiments provide a capacitive voltage multiplier for efficiently producing multiples, including fractional multiples, of a power supply voltage use high, medium and low voltage field effect transistors for switching terminals of various capacitors into and out of connection with power supply or ground voltages in charge mode and with an output or other capacitor terminals for series connection in pump mode. A single non-overlapping clock is level-shifted up to the maximum voltage level required for switching to produce a desired output, then level shifted back down to lower levels with delay added as necessary according to embodiments.

A system master unit is connected to a 24V AC power source. One or more slave units is connected to the master unit by a power / communication line. Bulk capacitance in the master and slave units stores power during a power source positive half cycle. When the source voltage is higher than the bulk capacitance voltages, power is delivered to the loads, during which time communication cannot take place over the power / communication line. During the power source negative half cycle, the power / communication line is disconnected from the AC power source and is then used for communication between the master and slave units. System power is delivered from the energy stored in the bulk capacitance.

A shield electrode is provided in parallel with a sensor electrode. A detecting circuit detects a capacitance formed thereby around the sensor electrode. A capacitance-voltage conversion circuit converts the capacitance into a voltage by repeating a predetermined sequence. A shield electrode drive unit switches an electric state of the shield electrode in synchronization with the predetermined sequence. The shield electrode drive unit switches an electric state of the shield electrode in accordance with an electric state of the sensor electrode.

Disclosed are systems and methods which provide voltage conversion in increments less than integer multiples of a power supply (e.g., battery) voltage. A representative embodiment provides power supply voltage multipliers in a binary ladder distribution to provide a desired number of output voltage steps using a relatively uncomplicated circuit design. By using different sources in various combinations and / or by “stacking” different sources in various ways, the voltage multiplier circuit may be used to provide desired voltages. In order to minimize the number of components used in a voltage converter of an embodiment, a capacitive voltage converter circuit uses one or more storage capacitors in place of pump capacitors in a voltage generation cycle. Also, certain embodiments do not operate to generate an output voltage until the time that voltage is needed.

This invention relates to a method for controlling capacity and voltage at the DC side uniformly of bridge-H cascade active power filter, which first of all takes the harmonic current, passive current needed to be compensated by the power net and load system as the compensation current required by the filter, takes the sum of the expected compensation current and fundamental wave positive sequence active current absorbed from the net as the APF reference current to get the APF inverter desired output voltage via a current following controller to drive the APF output current to follow the reference current, computes the micro-tune volume of the output voltage of the cascade unit, carries out micro-micro adjustment to the expected output voltage by the balance controller based on the cascade unit capacitance and voltage deviation and the APF output current to adjust the charge and discharge time of the unit floating capacitance to further realize the balance control of the floated capacitance and voltage takes the adjusted expected output voltage as the reference one of said unit to be modulated in pulse width to get trigger signals of the cascaded bridge-H power device to drive the primary circuit power device.

The invention relates to a modularized multi-level converter with an auxiliary diode. The modularized multi-level converter comprises a three-phase valve body, and three active energy feedback circuits respectively connected to the three-phase valve body, wherein each phase of valve body comprises 2M half-bridge inversion units and 2M-1 auxiliary diodes; direct current capacitors of the 1-(2M-1)th serially connected half-bridge inversion units are respectively connected with one auxiliary diode, and the final (2M)th half-bridge inversion unit is serially connected to form the valve body; the 1-Mth half-bridge inversion units form the upper-half part of the valve body to output a negative polarity voltage; and the (M+1)th to 2Mth half-bridge inversion units form the lower-half part of the valve body to output a positive polarity voltage. The auxiliary diodes and the active energy feedback circuits form a capacitor voltage sharing loop, the modularized multi-level converter realizes capacitance self voltage sharing effect, and realizes that the unit capacitance voltage is measured by using less direct current voltage sensors, thus the detection and the control of multi-level topology are greatly simplified. The modularized multi-level converter can be used in occasions such as reaction compensation and harmonic treatment of a medium-voltage or high-voltage power grid.

The invention discloses a control circuit for a voltage dropping type power factor corrector, which is used for controlling a voltage dropping converter to realize the power factor correction function. Inductance current critical intermittent control of changed on-time is performed on a Buck circuit through the control circuit to ensure that the on-time of a switching tube rises in the power frequency period along with increase of input voltage; and the critical intermittent working mode of inductance current in the Buck circuit is controlled, and when the inductance current is greater than zero, the junction capacitance of the switching tube and inductance are resonated, and the switching tube is connected when the voltage resonance of the junction capacitance reaches the volley bottom. The control circuit for the voltage dropping type power factor corrector has the characteristics of ensuring high power factors in the whole input voltage range, and meeting the harmonic requirements of IEC 61000-3-2 Class C, Class D, along with high efficiency.

An energy harvesting circuit harvests energy from a voltage source and charges a storage element with the harvested energy. The energy harvesting circuit includes an energy source, a storage capacitor to store energy output from the energy source, a power converter circuit, an energy storage element, and an enabling circuit. The enabling circuit turns the boost converter circuit on and off according to a monitored capacitance voltage of the storage capacitor. When the boost converter circuit is turned off, the storage capacitor accumulates energy output from the energy source until a reference voltage is reached, whereupon the boost converter circuit is turned on, enabling current flow from the storage capacitor to the storage element. When the storage capacitor discharges to a minimum voltage level, the boost converter circuit is turned off. The enabling circuit and a reference voltage supply are powered by the energy source.

A sensor and sensor module with small power consumption and high reliability are disclosed. The sensor includes a capacitor having a capacitance varying with a physical quantity, a capacitance-voltage conversion circuit for converting the capacitance of the capacitor into a voltage, and a control signal generation circuit for generating a plurality of control signals. The capacitor has a frequency-capacitance characteristic with a resonant frequency. In a measurement of the physical quantity, the capacitance of the capacitor is measured with one of the control signals having a first frequency which is much higher or much lower than the resonant frequency. In a self-diagnosis of the sensor, the capacitance of the capacitor is measured with another one of the control signals having a second frequency which is equal or close to the resonant frequency.

A capacitive humidity sensor includes a detection portion and a reference portion. The detection portion includes detection electrodes and a moisture sensitive film. The reference portion includes reference electrodes and a moisture permeation film as a capacitance adjusting film. The capacitive humidity sensor detects humidity by converting a capacitance difference between a capacitance of the detection electrodes and a capacitance of the reference electrodes to an electric signal by using a capacitance-voltage conversion circuit. The moisture permeation film reduces offset voltage of the capacitive humidity sensor. Thus, an offset compensation circuit or the like is not required.

The invention discloses an optimal pressure equalizing control method of a modular multilevel converter type direct current transmission system. By setting an upper limit and a lower limit on voltage, the pressure equalizing control is mainly carried out on submodules with out-of-limit capacitor voltage, and capacitor voltage sequencing for submodules with no out-of-limit capacitor voltage is processed by combing the charging / discharging conditions of bridge arm current so as to increase the probability of maintaining an original switching state for the submodules with no out-of-limit capacitor voltage when the next action is in triggering control and lower the switching frequency of devices. The introduction of the pressure equalizing control can not lower the working frequency of triggering control and the tracking speed of a converter by using submodule capacitor voltage sequencing and triggering control to work at different frequencies. The optimal pressure equalizing control method of the invention can greatly lower the switching frequency of the devices on the premise of having no obvious increment on submodule capacitor voltage fluctuation.

The invention discloses a robust dicyclic photovoltaic grid-connected control method based on power feedforward, which mainly comprises three parts: proportion integration (PI) control of exocyclic voltage, dead-beat control of endocyclic robust predictive current and power feedforward control, wherein the exocyclic PI control of the voltage is used for stabilizing the capacitive voltage of a direct-current side; the dead-beat control of the endocyclic robust predictive current is used for carrying out linear prediction on the voltage of a power grid at a next control period and carrying out non-linear prediction on grid-connected current by advanced control so as to obtain the command value of the grid-connected current at the next period; and then, PWM (pulse-width modulation) and grid-connected control are realized by the dead-beat control. According to the robust dicyclic photovoltaic grid-connected control method based on the power feedforward, a photovoltaic grid-connected inverter has higher robustness, wider stability margin and quicker dynamic response, and the requirement of grid-connected running of an inverter is better met.

The invention belongs to the power transmission and distribution field, and specifically relates to a pulse width control method of a modular multilevel converter. The method is characterized by determining the switched number of submodules at any time by carrier phase-shifting and then determining switching of the specific submodules by capacitance-voltage balance control, and comprising the steps of carrier comparison, signal acquisition, signal processing, PWM pulse signal generation and the like. The pulse width control method is simple, scientific and reasonable and easy for engineering realization, and has good dynamic property, thus being applicable to occasions with wider range of frequency variation in an AC system and free from restriction of the level number.

A NAND architecture non-volatile memory device and programming process is described that reduces the effects of word line to word line voltage coupling by utilizing sets of two or more adjacent word lines and applying the same voltage to each in array access operations. This allows each word line of the set or pair to shield the other from word line to word line capacitive voltage coupling. In NAND memory string embodiments the various cells of strings of non-volatile memory cells are programmed utilizing modified or unmodified drain-side self boost, source-side self boost, local self boost, and virtual ground programming processes that utilize two or more “blocking” memory cells on either the source line side and drain line side of a selected memory cell. The paired blocking cells shield each other during programming to reduce coupled noise, to prevent charge leakage from the boosted channel of the selected memory cell.

A purpose of the present invention is disclosing a flyback type miniature photovoltaic grid connected inverter with a power decoupling circuit and a control method thereof. The inverter comprises a flyback converter and a power frequency polarity conversion circuit. The flyback converter is provided with a power decoupling circuit, a decoupling capacitance voltage grade is higher than output voltage of a solar energy photovoltaic array, decoupling capacitance voltage is allowed to fluctuate in a large range, thus decoupling capacitance capacity is decreased, power decoupling can be realized by only using a non-electrolytic capacitor, using an electrolytic capacitor is avoided, a service life of the miniature photovoltaic grid connected inverter is prolonged, and reliability is raised. Through the control method, not only is decoupling of miniature photovoltaic grid connected inverter output power and solar energy photovoltaic array output power realized, but also direct current voltage and current waveform outputted by the solar energy photovoltaic array can maintain smooth, a service life of the solar energy photovoltaic array is guaranteed, and realization of maximum power point tracking (MPPT) is facilitated.

The invention provides an electronic power transformer based on a multi-media card (MMC). The electronic power transformer based on the MMC comprises the MMC and a direct current-direct current (DC-DC) isolator. The MMC comprises a plurality of sub-modules which are connected in series, the direct current output side and the direct current input side of the DC-DC isolator are respectively connected with capacitors in parallel, the direct current output side of the DC-DC isolator is connected with a low voltage direct current power grid, the direct current input side of the DC-DC isolator is connected with the direct current output ends of the sub-modules, and each sub-module comprises a half-bridge circuit and a capacitor, wherein the half-bridge circuits and the capacitors are connected in parallel. When direct current capacitor voltage of the MMC is unbalanced, the sub-modules with high capacitor voltage in the MMC charge the capacitors with low voltage to raise voltage values through the DC-DC isolator with the help of the low voltage direct current power grid and then through the DC-DC isolator again, stability of voltage on the direct current side is guaranteed, and therefore automatic balance of the direct current capacitor voltage of the MMC is achieved.

The invention relates to a sub-module circuit board used for a dynamic simulation test for simulating a high-capacity multi-level modular converter (MMC). A digital controller on the circuit board is used for controlling a plurality of MMC sub-modules of which parameters are reduced according to an exponential method, the sub-modules are connected in series. Each MMC sub-module comprises a main circuit an insulated gate bipolar transistor (IGBT) and silicon controlled rectifier driving circuit, a capacitance and voltage sampling circuit, a circuit board isolation power supply, a control and coding-decoding chip shared by a plurality of sub-modules, and a fiber channel, wherein the main circuit a capacitor, two IGBTs which are connected vertically in series and connected with the capacitor in parallel, a bypass switch connected with the lower IGBT in parallel, and a silicon controlled rectifier which is used for protecting the IGBTs and the capacitor and connected with the lower IGBT.

Dynamic range of a differential pixel is enhanced by injecting, synchronously or asynchronously, a fixed compensating offset (ΔV) into a differential signal capacitor whenever magnitude of the differential signal across the capacitor exceeds a predetermined value. The number (N) of ΔV offsets made is counted. Effective differential signal capacitor voltage V(t)=Vo+N·ΔV, where Vo is capacitor voltage. Differential pixel signal / noise ratio is increased by dynamically maximizing operational amplifier gain AG for each differential pixel.

The invention relates to a modular multi-level converter capacitor voltage fluctuation inhibition method under a low-frequency working condition, and belongs to the technical field of power electronics and motor drive. The method comprises the following steps: the alternating-current side three-phase phase current which meets the low-frequency working need is obtained by performing closed-loop control on the modular multi-level converter alternating-current side three-phase phase current; loop current only contains a direct-current component and a high-frequency alternating-current component by closed-loop control of the three-phase loop current, and a bridge arm voltage contains a high-frequency zero sequence component by overlapping high-frequency voltage at the midpoint electric potential at the direct-current side; the amplitude values, the frequencies and the phases of the loop current high-frequency alternating-current component and the bridge arm voltage high-frequency zero sequence component are obtained by operation, so that the phase voltage and the phase current of the alternating-current side do not contain high-frequency harmonic waves, moreover, the cycles of charging and discharging submodules are shortened, and the effect of inhibiting the capacitor voltage vibration of the submodules is realized; the electrical quantity of each bridge arm is kept to be balanced by the balancing control on the bridge arm energy so as to guarantee that the modular multi-level converter runs symmetrically and stably.

A sulfur hexafluoride gaseous discharge micro component infrared detection device and method relates to a sulfur hexafluoride gaseous infrared absorption spectrum analysis device and method. The device of the invention mainly comprises an induction voltage regulator, a corona free experimental transformer, a non local discharge protective resistor, a standard capacitance voltage divider, a GIS analogue element, a non inductive resistance, a Fourier transform infrared spectrometer and a wideband high speed super capacity digital storage oscilloscope; wherein the gas tank in the Fourier transform infrared spectrometer is a long optical distance one. The method of the invention includes that discharge micro component detection is carried out on SF6 gas sample in GIS by utilizing the device ofthe invention. The invention can accurately detect various products produced by gas discharge decomposition of SF6 and has the characteristics of high detection precision, high spectrum resolution, good absorption peak symmetry, high signal to noise ratio and the like. The invention can be widely applicable to GIS equipment online running local discharge and provides reliable data for GIS equipment online running state analysis.

The invention belongs to the control field of electric power electron converters and relates to a model prediction control method for a three-level voltage-source-type converter. The model prediction control method for the three-level voltage-source-type converter comprises the following steps: step one, building models of relations between currents of the alternating current side of the three-level voltage-source-type converter and switch functions; step two, building models of relations between capacitance voltage offsets of the direct current side and switch functions; step three, obtaining current instruction values through outer voltage loops and obtaining a current instruction value of the next moment by calculating current instruction values of several moments before; step four, setting value functions of a model prediction control algorithm for the three-level voltage-source-type converter; step five, calculating on-off state subsets; step six, achieving real-time prediction control. The model prediction control method for the three-level voltage-source-type converter is simple in algorithm, easy to achieve and capable of being adopted in a higher-level converter, and has generality.

The invention relates to a circuit breaker and a realization method thereof, and specifically relates to a mixed high-voltage direct-current circuit breaker and a realization method thereof. The direct-current circuit breaker is based on the principle of secondary current transfer. A main branch is composed of a quick-action mechanical switch and a current transfer module which contains a full-controlled device, which ensures the advantages of low loss and flexible current transfer control in the state of normal conduction. A first current transfer branch is composed of half-controlled device thyristors connected in series, so that the circuit breaker has strong fault flow capacity and breaking capacity, 'zero voltage and zero current' of the mechanical switch can be maintained long enough, and arc-free switching of the mechanical switch is realized. A second current transfer branch is composed of capacitors with pre-charged voltage, an inductor, and series-connected thyristors. After the thyristors of the first current transfer branch are reliably switched off, the capacitors quickly build up direct voltage high enough to resist the system, and an energy absorption circuit limits the voltage of the capacitors. Thus, the size and cost of the capacitors are well controlled.

The invention relates to an energy transfer type power battery quick balancing system and a control method thereof. The invention relates to the battery voltage balancing system and further relates to the control method of battery pack quick balancing process, which solves the problem that a balanced battery single body and an energy storing element are impacted through pulse current by a currentbalancer in the prior art. The system comprises a power battery pack single body battery voltage and flying capacitor voltage detecting network, a current sensor and a signal modulating circuit, a single chip microcomputer, an electric power transfer channel, a first filter circuit, a two-way buck-boost converter, a second filter circuit and a flying capacitor. After starting to work, the system firstly detects the battery pack single body battery voltage, the flying capacitor voltage and the charging / discharging current; and if the dropout voltage between the highest voltage of the battery single body and the lowest voltage of the single body exceeds a set value, the balancing operation is started.

The invention provides a relaxation oscillator of which the linearity is significantly improved. The relaxation oscillator comprises an oscillating circuit, a reference level self-regulating circuit and a transmission gate selective signal generating circuit. Capacitor voltage overshoot caused by delay of a control circuit is worked out by detecting the voltage peak of charge and discharge capacitors in the oscillating circuit, and accordingly the reference level of comparators in the oscillating circuit is reduced by a corresponding quantity to serve as a new reference level so that the oscillation amplitude of the charge and discharge capacitors can be just a theoretical value. According to the high-linearity relaxation oscillator, when the new reference level is larger than zero, influence, brought by the capacitor voltage overshoot caused by delay of the control circuit, of the charge and discharge capacitors on output frequency is eliminated, and the linearity of a frequency-control circuit of the relaxation oscillator is significantly improved. The transmission gate selective signal generating circuit provides the initial reference level for the comparators by controlling transmission gates and transmits the new reference level to the reverse phase ends of the comparators when the new reference level is generated, and therefore the initial reference level can be isolated from the reverse phase ends of the comparators.

Capacitive voltage multiplier for generating voltage pulses, preferably up to 100 V, that are higher than the supply voltage for displays, non-volatile memories and corresponding units especially in small electronic devices, such as handheld telecommunication terminals or corresponding devices, wherein the multiplier comprises a switching capacitor circuit (21) provided with capacitors and switches for charging the capacitors in parallel and discharging them in series in order to deliver a high voltage pulse. The multiplier further comprises a diode chain circuit (22) consisting of a diode-chain and pumping capacitors for delivering high voltage current. The inventive system allows the output high voltage to be switched on and held with little longtime drop and with small switching losses and able to supply a load current without significant ripple. Additionally switching the high voltage on and off does not result in efficiency loss.

The invention provides an online monitoring method for a DC-link capacitor of a three-phase system. The method comprises that voltage of the DC-link capacitor is collected, and a voltage drop curve of the DC-link capacitor is obtained; three-phase output current is collected, and capacitive current is reconstructed according to the three-phase output current; and the capacitance (C) and equivalent serial resistance (ESR) of the DC-link capacitor are obtained according to the voltage drop curve and the capacitive current of the DC-link capacitor. The voltage drop curve and the three-phase output current of the DC-link capacitor as well as control signals of a semiconductor switch are monitored in the process that power equipment as a three-phase frequency converter is switched off, so that the C and ESR of the DC-link capacitor are calculated accurately, and non-invasive online monitoring for the DC-link capacitor of the AC / DC / AC system is realized. The method can be applied to online monitoring for an aluminum electrolytic capacitor, other capacitors as a film capacitor as well as other three-phase systems including a wind power converter, a photovoltaic AC / DC / AC system and a three-phase aviation power system.

The invention provides a single-phase five-level topology and an inverter. The single-phase five-level topology comprises a first capacitor, a three-level bridge arm module and four switching tubes, wherein the four switching tubes refer to a first switching tube, a fifth switching tube, a sixth switching tube and an eighth switching tube respectively; each switching tube is reversely connected in parallel with a diode; the three-level bridge arm module comprises two switching tubes and a double-switch unit; the first end of a third switching tube is connected with a first node, and the second end of the third switching tube is connected with a neutral point N through the double-switch unit; and the first end of a fourth switching tube is connected with N through the double-switch unit, and the second end of the fourth switching tube is connected with a second node. Five level states are output, the current harmonic content of a system is reduced, the filter inductance is reduced, the voltage level is raised, the common-mode voltage is restrained, and the running efficiency is increased. Balanced control of capacitor voltage under full power and full modulation can be realized without adding an additional hardware circuit, and the phase output voltage of the system is prevented from degrading from five levels to three levels.

The invention relates to the technical field of photovoltaic grid-connected inverters, particularly to a method for detecting the failure of relays and protecting filter capacitors of photovoltaic grid-connected inverters. The method comprises the following steps: before the relays are closed, if the difference of the absolute values of the effective value (Vinv) of one-phase or multi-phase inversion voltage and the effective value (Vgrid) of the same-phase grid voltage is detected to be smaller than the failure voltage threshold (delta V) of the relays, namely the absolute value of(Vinv-Vgrid)is smaller than delta v, judging that the relays in the phase are adhered, otherwise, judging that the relays are normal; similarly, after the detection of the relays on closed inversion sides, the detection of the relays on closed grid sides, and the closed detection of the relays on both sides are successively performed by the same method, if the relays have no failures in every step, grid connection is allowed, if any relay has a failure, machines are stopped, and grid connection is denied. According to the method disclosed by the invention, when every relay is accurately detected to have a failure or not, the filter capacitor voltage output by the inverters is processed, so that the possibility that at the moment of grid connection of the inverters, the grids generate current impact on the filter capacitors is eliminated, the system stability of the inverters is improved, and the service life of the filter capacitors is prolonged.