345 results about "Level converter" patented technology

A multiple input converter for outputting power from AC power or a battery to positive and negative direct current (DC) buses is provided. The multiple input converter includes at least one bridge arm unit and a bidirectional DC-DC conversion unit. The bridge arm unit corresponds to one phase of the alternating current (AC) power and includes an upper and lower bridge arms that can independently form a two-level converter. In a battery mode, the upper and lower bridge arms discharge power from the rechargeable battery to the positive and negative DC buses, and the bidirectional DC-DC conversion unit discharges power from the rechargeable battery to the positive and negative DC buses or balances voltages of the positive and negative DC buses. In a mains mode, the bridge arm units are connected to the AC power. The bidirectional DC-DC conversion unit determine whether to charge or discharge according to load conditions.

The invention is suitable for the technical field of flexible power distribution of a power system, and discloses a modular multilevel converter multi-objective optimization method, system and device based on model predictive control and space vector modulation, and a medium. Obtaining an output current reference value and a circulating current reference value; obtaining a reference voltage vector based on the output voltage reference value, and screening out a plurality of groups of redundant voltage vector sequences through a space vector diagram; performing performance evaluation through rolling optimization by combining each redundant voltage vector sequence with a multi-target cost function to obtain an optimal voltage vector sequence; and on the basis of the optimal voltage vector sequence and the corresponding duty ratio, a switching signal for driving each sub-module switching device of the MMC is generated, and multi-target cooperative control is realized. The three targets of reference output current tracking, circulating current suppression and sub-module capacitor voltage balance are met, and the dynamic response capability, efficiency and reliability of MMC system operation are comprehensively improved.

The invention discloses a display device, a control method thereof and display equipment, and relates to the field of display, the display device comprises a time schedule controller, a power management module, a display panel and a plurality of level converters, the display panel comprises a plurality of pixel areas, and each pixel area comprises at least one pixel row; the time sequence controller is connected with the time sequence input end of each level translator, the power supply management module is connected with the voltage input end of each level translator, each pixel region is connected with the time sequence output end of one level translator, and different pixel regions are connected with different level translators; the level converter is used for receiving a time sequence reference signal sent by the time sequence controller and is also used for receiving a target grid high-level voltage sent by the power supply management module; the level shifter is further configured to generate a timing control signal based on the target gate high-level voltage and a timing reference signal. The problem that the brightness display of the display panel is not uniform is solved.

Disclosed is a test device to test the operation of an MMC by fabricating only one or several SMs constituting the MMC testing under real-time operating conditions. The test device for a modular multi-level converter (MMC) includes a simulation model of an MMC having at least one arm to which sub modules (SMs) are serially connected, at least one test target SM among the serially connected SMs being replaced with a dependent voltage source; an arm current simulation circuit including an equivalent SM that implements the test target SM as actual physical hardware and an inverter that supplies current to the equivalent SM; and a control unit configured to control the arm current simulation circuit to correspond to an operation of the simulation model and set a voltage corresponding to a charge / discharge voltage of the equivalent SM of the arm current simulation circuit to the dependent voltage source.

The invention provides a unified carrier reverse lamination modulation method based on a three-level converter. The method comprises the following steps: acquiring the current three-phase reference voltage of the three-level converter; calculating a zero-sequence component of a current modulation strategy according to the three-phase reference voltage and the current modulation strategy; determining a three-phase modulation wave according to the three-phase reference voltage and the zero-sequence component; and generating a switching tube driving signal of each bridge arm in the three-level converter according to the three-phase modulation wave. According to the invention, through a unified zero-sequence component calculation mode, on the basis of carrier reverse-phase laminated modulation, compatibility with different modulation strategies is realized, a zero-sequence vector calculation process is omitted, a space vector region does not need to be judged, occupation of calculation resources when the modulation strategies are realized is effectively reduced, and the implementation efficiency of the modulation strategies is improved. And transient oscillation during strategy switching is suppressed.

The invention discloses a flexible direct-current power transmission system and a fault ride-through method and system thereof. The flexible direct-current power transmission system comprises a main control module, and a new energy sending-out system, an alternating-current energy consumption device, a sending-end converter, a direct-current circuit breaker, a receiving-end converter and a receiving-end alternating-current power grid which are connected in sequence, the direct current circuit breaker is deployed on a direct current power transmission line between the sending end converter and the receiving end converter, and the receiving end converter is a modular multi-level converter formed by cascading a plurality of half-bridge sub-modules with damping branches; the main control module is in communication connection with the half-bridge sub-modules, the direct-current circuit breaker and the alternating-current energy consumption device and used for controlling the damping branches of the half-bridge sub-modules in the running state, the direct-current circuit breaker and the alternating-current energy consumption device to act when a direct-current fault occurs so as to restrain direct current and adjust direct-current voltage to be within a set voltage range. Therefore, no-locking fault ride-through is completed. According to the invention, high-reliability and low-cost DC fault ride-through can be realized.

The invention provides a neutral-point potential control method and system for a three-level converter, and relates to the technical field of intelligent control, positive bus voltage and negative bus voltage are sampled, a voltage deviation value is calculated, an additional control quantity is generated according to the voltage deviation value and a symbol of alternating current, and the additional control quantity is obtained through a symbol function and proportional control processing; performing amplitude limiting processing on the additional control quantity to obtain an amplitude-limited additional control quantity; superposing the amplitude-limited additional control quantity on the positive modulation wave, negating the amplitude-limited additional control quantity, and superposing the negated amplitude-limited additional control quantity on the negative modulation wave to obtain a final positive modulation wave and a final negative modulation wave; comparing the final positive modulation wave and the final negative modulation wave with a carrier wave, and generating a driving signal of the power device; and the on-off of the switching device is controlled according to the driving signal, so that a corresponding level is output to realize neutral-point potential balance. According to the invention, neutral-point voltage low-frequency fluctuation and direct-current offset suppression can be realized at the same time.

The utility model relates to a distributed photovoltaic power station main converter, and belongs to the field of photovoltaic power generation. The main current transformer comprises a T-type three-level current transformer and a Buck-Boost current transformer; one end of the main converter is connected with a power grid, and the other end is connected with a photovoltaic module system and energy storage equipment of the distributed photovoltaic power station; the T-type three-level converter comprises three bridge arms, two output capacitors and the like; each bridge arm is provided with four power switch tubes; the two output capacitors are connected in series, and the connection point is called as the midpoint O of the T-type three-level converter. The Buck-Boost converter comprises a direct current inductor, two power switch tubes and the like; and one end of the direct-current inductor is connected with the midpoint O so as to realize midpoint potential automatic balance. The system is low in cost, simple in control, small in current harmonic wave, low in power consumption, and capable of realizing fast and automatic balance of neutral-point potential, thereby effectively coping with the influence of illumination and network voltage fluctuation on system control, and realizing fast and stable control of a distributed photovoltaic power station.

A level shifter includes a first buffer circuit, a first capacitor, a second capacitor, a cross-coupled inverter, and a second buffer circuit. The first buffer circuit is configured to drive a first input signal and a second input signal with a first high power supply voltage and a first low power supply voltage to generate a first main driving signal and a second main driving signal. The first capacitor, the second capacitor, and the cross-coupled inverter are configured to generate signals of a first node and a second node based on the first and second main driving signals. The second buffer circuit is configured to drive the signals of the first and second nodes with a second high power supply voltage and a second low power supply voltage to generate a first output signal and a second output signal.

The invention discloses an operation parameter optimization method and system for improving the overload capacity of a power electronic converter, and belongs to the technical field of power electronics. The method comprises the following steps: constructing an output current model considering current ripples in a switching period, and obtaining an accurate current waveform expression; calculating conduction loss and switching loss of each power device in each switching period based on the model; under a set temperature rise or loss constraint condition, parameters such as direct-current voltage and switching frequency are optimized through an optimization algorithm, and the optimized parameters are applied to converter operation. The method solves the problem that loss estimation is inaccurate due to the fact that a traditional simplified model ignores current ripples, through precise modeling, refined loss calculation and scientific parameter optimization, the thermal stress of a device is remarkably reduced, the overload capacity of the converter is improved, the method is suitable for various topologies such as a two-level converter, a three-level converter and a direct-current converter, and the method has wide application prospects. The method can be widely applied to the fields of new energy and rail transit.

A battery storage system includes a multilevel-converter and a plurality of storage sections. Each storage section includes at least one holding means configured to hold at least one battery and at least one cable with at least one connector configured to electrically connect at least one of the batteries. The multilevel-converter includes a plurality of converter modules connected in series with each other and each converter module has at least one bypass switch configured to bypass the converter module and a battery switch configured to disconnect the battery at the same time when the bypass switch is on. The battery storage system further includes a controller with means for detecting the presence of a battery in each storage section and means for configuring the switches of the plurality of converter modules based on the presence of batteries such that the plurality of converter modules provides a required voltage.

Equipping level converters: an input circuit (120) having a first input terminal (202) and a second input terminal (204) configured to receive complementary input signals at a first voltage level (VSSA) and a second voltage level (VDDA); a cross-latch circuit (110) coupled to the input circuit (120), wherein the cross-latch circuit (110) has a first output terminal (102) and a second output terminal (104) configured to provide complementary output signals at a third voltage level (VSSB) and a fourth voltage level (VDDB), wherein the input circuit (120) has a first control node (206) and a second control node (208) configured to output a first control signal and a second control signal at the first voltage level (VSSB) and the fourth voltage level (VDDB) based on the input signals; and a follow-up circuit (130) coupled to the input circuit (120) and the cross-latch circuit (110), configured to input a first tracking signal and a second tracking signal into the cross-latch circuit (110) based on the first control signal and the second control signal, wherein the first tracking signal is greater than the first control signal and the third voltage level (VSSB), and the second tracking signal is greater than the second control signal and the third voltage level (VSSB).

A control circuit for generating a control parameter that defines a state sequence of a power converter may include a loop filter configured to, based on an error signal between a reference current signal and a feedback current measurement signal, correct for unmodeled errors in the feedback current measurement signal to generate the control parameter. The control circuit may also include a first feedforward block configured to generate a first offset to the control parameter based on a slew rate of the reference current signal.

The present application relates to a kind of full digital hysteresis control method of inductance-free three-level inverter sampling time online prediction, belong to power electronic converter technical field, solve the dependence of full digital hysteresis control algorithm of three-level converter on high sampling rate, and the problem of being greatly influenced by main circuit filter parameter, it includes determining the mathematical model and modulation method of three-level converter, determining the full digital three-level hysteresis control algorithm of inductance-free sampling time online prediction, correction prediction sampling time interval.The full digital hysteresis control method is used for inductance-free three-level inverter hysteresis control simulation.

A device including an inverter circuit, a hysteresis control circuit, and a high-side input level shifter. The inverter circuit having an output and including at least two series connected PMOS transistors connected, at the output, in series to at least two series connected NMOS transistors. The hysteresis control circuit coupled to the output to provide feedback to the at least two series connected PMOS transistors and to the at least two series connected NMOS transistors. The high-side input level shifter connected to gates of the at least two PMOS transistors and configured to shift a low level of an input signal to a higher level and provide the higher level to one or more of the gates of the at least two PMOS transistors.

In some embodiments, a system comprises: a differential multi-level converter with a differential input for receiving two different voltages; a plurality of switches coupled between the input terminals; and a capacitor having a first terminal coupled to the first terminal of the first of the plurality of switches, and a second terminal coupled to the first terminal of the second, other of the plurality of switches; and an output terminal coupled to the first terminal of the third, other of the plurality of switches. The differential multi-level converter can be part of a hybrid power supply generator / modulator.The system may further include a controller configured to control selected switches from the plurality of switches so that they switch between a plurality of switching states at times, each switching state producing an output voltage corresponding to one of three discrete voltage levels.

The invention provides a pulse width modulation smooth switching method for a three-level converter, and the method comprises the steps: obtaining the neutral-point potential unbalance information of the DC side of a converter, and dynamically adjusting the balance control freedom degree through the neutral-point potential unbalance information, switching between the first modulation strategy and the second modulation strategy is carried out according to the balance control freedom degree, and the fundamental component of the output voltage is kept unchanged. According to the pulse width modulation smooth switching method of the three-level converter provided by the invention, half-bus voltage jump caused by hard switching of a dual-modulation wave pulse width modulation strategy and a single-modulation wave pulse width modulation strategy can be effectively suppressed, and the reliability of the converter is improved.

The application discloses an expansion board and a server, and relates to the technical field of servers, and comprises a logic controller, at least one power supply domain and at least one memory on the expansion board. The power supply domain and the memory are in one-to-one correspondence, the power supply domain can comprise a plurality of re-timers and a plurality of level converters, the level converters can be connected with the re-timers in one-to-one correspondence, and correspondingly, the re-timers belonging to one power supply domain can share one memory. In this way, the plurality of re-timers can share one memory, the number of memories is greatly reduced, hardware resources can be saved, and hardware cost is reduced. Moreover, in the process of upgrading or modifying firmware, the number of memories that need to be programmed and verified is greatly reduced, the operation and maintenance complexity is reduced, and then, the time cost is also reduced. In summary, through the plurality of re-timers sharing one memory, the cost can be reduced.

A kind of permanent magnet direct drive type medium-high voltage high-power wind power converter and control method, belong to power electronics technical field.The wind power converter adopts H bridge midpoint clamping type five-level converter topology, wherein wind generator side is five-level midpoint clamping type H bridge converter, grid side is three three-phase three-level midpoint clamping type grid-connected converter, its DC side is connected to wind generator side converter, grid side is connected to 66kV or higher voltage grid through isolated four-winding power frequency step-up transformer.The topology structure can improve wind generator voltage to 8.5kV, and can be used in 20MW and above power level wind power system.Compared with traditional wind power converter, it has the advantages of high rated voltage, less power device, no need for device or converter parallel, large single machine capacity, simple cable twisting, small cable loss, good harmonic characteristic, high fault tolerance, simple structure, easy to control, etc., and has important application prospect in medium-high voltage high-power offshore system.

A system may include an SCB2L comprising a plurality of switches, a first power inductor and a second power inductor electrically coupled to the plurality of switches, and a flying capacitor electrically coupled to the plurality of switches, wherein the plurality of switches are controllable in a periodic manner among a plurality of switch configurations in order to generate an output voltage from an input voltage received by the SCB2L. The plurality of switch configurations may include a first switch configuration in which electrical charge on the flying capacitor is increased and a second switch configuration in which electrical charge on the flying capacitor is decreased. The system may also include a control subsystem configured to selectively increase and decrease a difference in time between a first duration of the first switch configuration and a second duration of the second switch configuration within switching cycles of the SCB2L.

A 2-bit fast flash analog-to-digital converter circuit and related methods designed for use with multi-level converters in particular to achieve: high conversion speed, high resolution, small layout area, low power, and the ability to meet the requirements for properly balancing fly capacitor voltages. One embodiment includes a voltage input configured to be coupled to a multi-level converter fly capacitor; a comparator coupled to the voltage input and a first reference voltage input and having a first binary output indicating whether the input voltage is higher or lower than a voltage on the first reference voltage input; and a circuit coupled to the voltage input and to second and third reference voltage inputs, the circuit configured to provide a second binary output indicating whether the input voltage is inside or outside a voltage window defined by respective voltages on the second reference and third reference voltage inputs.

The application discloses a kind of T type three-level converter open-circuit fault diagnosis method with strong robustness, belong to the field of power electronic equipment fault diagnosis, to distinguish different switch similar open-circuit fault characteristics and accurately locate open-circuit fault tube.Considering different modulation strategies and modulation modes, the phase voltage residual is generated through the phase voltage model, so as to extract the fault characteristics of the converter under various open-circuit faults.Analyze the influence of factors such as parameter error, dead time and delay time of the system on the phase voltage vector residual, and the adaptive residual vector amplitude threshold based on uncertainty propagation theory.A hierarchical fault diagnosis scheme is proposed, which can locate the group-level open-circuit fault according to the voltage residual vector amplitude and angle, switch the three-level modulation mode of all phases of the converter to two-level mode, to further identify the specific fault switch from the fault group.A reasonable balance between robustness and speed can be achieved, and the complexity and adaptability of the diagnosis algorithm are fully considered.

A multi-level processing system, includes a multi-level converter, a voltage detection circuit and a control circuit. The multi-level converter includes a key element, several control switch elements and several target switch elements. The key element is electrically coupled to at least one of the control switch elements, and the key element has a voltage parameter set. The voltage detection circuit is electrically coupled to the key element of the multi-level converter to detect the voltage parameter set, and generate a detection voltage set according to the voltage parameter set. The control circuit is electrically coupled to the voltage detection circuit to receive the detection voltage set, and takes the detection voltage set as a control voltage set of the control circuit.

A circuit. In some embodiments, the circuit includes: a first pair of transistors, configured as a cross-coupled pair of transistors; a second pair of transistors, configured as another cross-coupled pair of transistors; and a first series combination of one or more voltage clamping transistors. A first transistor of the first pair of transistors may have a current-carrying terminal electrically coupled to a first end terminal of the first series combination of one or more voltage clamping transistors, and a first transistor of the second pair of transistors may have a first current-carrying terminal electrically coupled to a second end terminal of the first series combination of one or more voltage clamping transistors.

A multilevel converter (1) comprises a plurality of bit cells (31-35) that output DC voltages different from one another. Each of the bit cells (31-35) includes switching elements (Q1-Q4) configured to charge or discharge a power storage element (C) by performing a switching operation in response to a control command from a control device (7). The control device (7) repeatedly outputs a plurality of switching patterns in which control commands for the bit cells (31-35) are arranged in time series. The switching patterns are temporally symmetrical for each cycle, and are determined such that the length of a charging period and the length of a discharging period for the power storage element (C) are equal.

The present disclosure belongs to the technical field of three-phase five-level converter, and particularly relates to a flying capacitor type three-phase five-level inverter and a control method and system thereof, which comprises a DC side topology adopting a DC power supply; an inverter topology comprising first, second, third, fourth, fifth and sixth power switching tubes connected in series; seventh and eighth power switching tubes connected in parallel between the third and fourth power switching tubes; a third flying capacitor connected in parallel between the third and fourth power switching tubes; a first flying capacitor connected in parallel between the second and third power switching tubes; and a second flying capacitor connected in parallel between the fourth and fifth power switching tubes; and the seventh and eighth power switching tubes are connected in series.

A battery energy storage system includes a plurality of battery cores. Each battery core of the battery energy storage system includes an array of battery cubes, and each battery core is configured to provide a first direct current power at a first voltage. The battery energy storage system further includes a plurality of direct-current-to-direct-current (DC-DC) converters. Each DC-DC converter of the battery energy storage system is configured to accept the first direct current power and each DC-DC converter is configured to provide a second direct current power at a second voltage. The battery energy storage system further includes a main modular multilevel converter (MMC). The MMC of the battery energy storage system is configured to accept the second direct current and to provide an alternating current at a third voltage.

A power supply device comprises: a switching converter using input power of AC or DC supplied through an input power unit, having a switch, and generating output power by using an on-off action of the switch; a driving controller generating a first control signal for controlling the on-off action of the switch of the switching converter; a level converter receiving the first control signal from the driving controller and outputting a second control signal to the switch of the switching converter, and a voltage generator supplying a power source to at least one among the switching converter, the driving controller, and the level converter.

This invention relates to a method and apparatus for high-speed flywheel multi-level wide-modulation specific energy balance cyclic control. The method is applied to the recycling of regenerative braking energy in subway traction power supply systems. By selectively employing a bubble sorting-carrier phase-shift modulation method to maintain the voltage balance of sub-module capacitors, it can maintain voltage balance even when the voltage difference between sub-module capacitors is large, and generate PWM signals to control the switching on and off of sub-module switching devices, thus solving the problem of voltage balance control for modular multi-level converter sub-modules under high-frequency fundamental frequencies. This apparatus can be installed on the DC traction network side of the subway traction power supply system to recycle the subway's regenerative braking energy, perfectly matching the instantaneous energy demands of frequent subway starts and stops. Compared with existing technologies, this invention, utilizing a wide-modulation specific energy balance cyclic control method, achieves an energy-to-kinetic energy conversion efficiency of 90%-95%, far exceeding traditional energy storage systems.