1088 results about "Level converter" patented technology

In some embodiments, a system includes: a differential multilevel converter comprising a differential input to receive two different voltages; a plurality of switches coupled between the input terminals; and a capacitor having a first terminal coupled to a first terminal of a first one of the plurality of switches and a second terminal coupled to a first terminal of a second, different one of the plurality of switches; and an output terminal coupled to a first terminal of a third, different one of the plurality of switches. The differential multilevel converter can be part of a hybrid supply generator / modulator. The system can further include a controller configured to control selected ones of the plurality of switches to switch, at points in time, between a plurality of switch states with each switch state producing an output voltage corresponding to one of three discrete voltage levels.

Provided in the present invention is a transformerless unified power quality conditioner, comprising a three-phase conditioner substructure, wherein each phase of the conditioner substructure can comprise an ANPC three-level converter and an output half-bridge module connected to the ANPC three-level converter. Also provided are a corresponding modulation method and system and a corresponding control method and system. Compared with existing voltage regulation apparatuses, the transformerless unified power quality conditioner and the modulation method and control method therefor provided in the present invention do not include a power-frequency transformer in the topology, but use a three-level converter to expand ports to realize voltage regulation, thus having the advantages of lower costs, smaller size, smaller footprint, lower loss, etc.

The invention discloses a direct-current power transmission receiving end and a direct-current power transmission system. The direct-current power transmission receiving end comprises an inverter circuit and a receiving end transformer; the inverter circuit comprises a hybrid power grid commutation converter and a modular multi-level converter; a direct current first end of the hybrid power grid commutation converter is used for connecting a direct current power transmission line, a direct current second end of the hybrid power grid commutation converter is connected with a direct current first end of the modular multilevel converter, and an alternating current end of the hybrid power grid commutation converter is connected with a receiving end alternating current bus through a corresponding receiving end transformer; the direct current second end of the modular multilevel converter is grounded, and the alternating current end of the modular multilevel converter is connected with the receiving end alternating current bus through the corresponding receiving end transformer. In the embodiment of the invention, the hybrid power grid commutation converter and the modular multi-level converter which are connected in series are used at the direct-current transmission receiving end, so that the direct-current transmission receiving end has direct-current side fault ride-through capability and alternating-current side fault ride-through capability.

The invention discloses a clamping type multi-level converter and a control method, relates to the field of clamping, and aims to enable the voltage of a flying capacitor in the multi-level converter to be 1 / (N-1), 2 / (N-1)... (N-2) / (N-1) times of Vbus voltage (bus voltage) even if the voltage of the flying capacitor is in a steady state. The number of the clamping units is the same as that of the flying capacitors, and each flying capacitor is connected in series with the equivalent capacitors of the corresponding number of bus capacitors through the corresponding clamping unit when the multi-level converter switching tube is closed, so that each flying capacitor is clamped through the voltage of the corresponding number of equivalent bus capacitors; and the voltage of the flying capacitor in the multi-level converter can be ensured to be in a steady state without closed-loop control.

The invention discloses a neutral-point potential balancing method and device for a three-level converter suitable for an unbalanced load, and belongs to the technical field of three-level converter control, and the method comprises the steps: 1, carrying out the positive and negative sequence separation of a sampling signal, and achieving the output of a three-phase balanced voltage; step 2, calculating an ideal zero-sequence component needing to be added in the modulated wave; step 3, analyzing the adjustment capability of adding the ideal zero-sequence component, and if the adjustment capability is satisfied, executing step 4; if not, skipping to step 7; 4, correcting a modulation wave symbol in the ideal zero-sequence component; 5, designing a potential regulator of the zero-sequence voltage based on the corrected modulation wave symbol; 6, performing amplitude limiting on the sum of the zero-sequence component generated by the potential regulator and the ideal zero-sequence component; step 7, carrying out midpoint balance by using an external balance circuit; and the three-level converter stops running, and the process is ended. According to the invention, neutral-point potential balance of the three-level converter is realized by adding the zero-sequence component in modulation.

The invention relates to a networking type three-level converter control system and a dynamic configuration method thereof, the networking type three-level converter control system comprises a redundant main control unit, a function unit, a six-phase power unit and a chopping unit, the redundant main control unit is connected with the function unit through an optical fiber, the function unit is respectively connected with the six-phase power unit and the chopping unit through optical fibers, and the chopping unit is connected with the six-phase power unit. The chopping unit is connected with the two ends of the direct current capacitor side of the inversion unit of the six-phase power unit; the main control unit and the pulse distribution unit are compact in sampling and modularized in design, small in occupied space, comprehensive in function, high in expandability and excellent in control performance, a dynamic configuration method is adopted, the redundant main control unit can be replaced on line, no power-on sequence requirement exists between the main control unit and each functional unit, and the power-on reliability is high. According to the invention, parameters of the pulse distribution unit can be forcibly updated on line, each functional module is independent, a more complex control system can be combined, and the system is convenient to use and maintain and is suitable for application occasions of complex control systems such as a network-forming converter and the like.

The invention provides a modularized multi-level converter current control method based on feedforward analysis. The deviation between the direct-current side voltage and the reference value is stably monitored in real time based on the direct-current bus voltage, a first waveform signal is dynamically generated, and the direct-current side voltage fluctuation range is limited. According to the circulating current interphase voltage sharing, the dynamic deviation between the actual value and the rated value is calculated by collecting the capacitor voltage actual value of the bridge arm sub-module, and a second waveform signal is generated to balance the circulating current distribution of each phase of bridge arm. The loop current suppression based on feedforward analysis generates a third waveform signal to compensate for high-frequency loop current interference through real-time comparison of theoretical modeling and actual loop current components. In the modulation wave generation process, information in all aspects is integrated to accurately control the on-off state of the sub-module, so that the operation effect of the system is improved under the complex working condition, and the real-time performance and predictability of control are considered through combination of closed-loop adjustment and feed-forward compensation, so that the effectiveness of control is improved.

The invention relates to the technical field of power electronics, in particular to a multi-level converter midpoint voltage dynamic balance control method, which comprises the following steps: acquiring positive bus voltage and negative bus voltage, and calculating deviation voltage of a DC side midpoint based on the positive bus voltage and the negative bus voltage; on the basis of the positive bus voltage, the negative bus voltage and the calculated deviation voltage of the direct current side midpoint, the duty ratio in the current switching period is calculated by combining the obtained balance bridge current, the obtained balance bridge inductance value and the switching period; determining the duty ratio of upper and lower tubes of the balance bridge according to the comparison result of the deviation voltage and preset positive and negative threshold values; and carrying out carrier wave comparison based on the determined duty ratio of the upper and lower tubes of the balance bridge, generating a PWM signal and driving the upper and lower tubes of the balance bridge. According to the invention, the requirements of high responsiveness and high precision of the multi-level converter on the neutral-point voltage balance performance under the dynamic operation condition can be met.

The invention provides a display device and a driving method thereof, and a display terminal, a level converter in the display device is used for generating a first clock signal, and a time schedule controller generates a control signal when a refresh rate is greater than a preset value for controlling the level converter to process the first clock signal to generate a second clock signal. The second clock signal comprises a plurality of second clock pulses in one-to-one correspondence with a plurality of first clock pulses in the first clock signal, and the ending time of the second clock pulses is later than the ending time of the corresponding first clock pulses, so that the risk of wrong charging under a low refresh rate is reduced.

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 discloses a multi-phase-multi-phase direct-type AC-AC converter based on an MMC and a control method of the multi-phase-multi-phase direct-type AC-AC converter. The AC-AC converter provided by the invention comprises a modular multi-level converter and N single-phase three-winding transformers, the modularized multi-level converter comprises X phase units, the input side is provided with m ports and connected with a first alternating current system, and the output side is provided with N ports and connected with a second alternating current system. Each single-phase three-winding transformer comprises a first winding, a second winding and a third winding, the first windings of the N single-phase three-winding transformers are respectively connected with N phases of a second alternating current system, and the second windings are connected with N output side ports of an upper bridge arm of the modular multilevel converter; and the third winding is connected with N output side ports of the lower bridge arm of the modular multilevel converter. The AC-AC converter is based on the principle of synthesis of differential-mode and common-mode voltage components of MMC bridge arms, and is combined with a three-winding transformer with an anti-dotted terminal, so that the number of sub-modules of the M3C topology can be further reduced, and the AC-AC converter has good expansibility and is suitable for application scenes with various special requirements.

In an example, a level shifter includes a low side having first and second inputs. The level shifter also includes a high side, where the high side has a latch having first and second terminals. The high side also includes a current comparator including first and second current mirrors. The high side includes isolation circuitry including first and second transistors, in which the first transistor has a first control terminal, the second transistor has a second control terminal, the first transistor is coupled between the first terminal and the first current mirror, the second transistor is coupled between the second terminal and the second current mirror, the first control terminal is coupled to the second current mirror, and the second control terminal is coupled to the first current mirror.

The invention discloses a low-cost charging pile topology for a fast charging-slow discharging scene of an electric vehicle and a modulation strategy of the low-cost charging pile topology. According to the low-cost charging pile topology, a group of half-bridge type shunt diodes are connected in parallel to each phase of main bridge arm of a traditional T-shaped three-level converter. In the discharging mode, the charging pile is consistent with a traditional T-type three-level operation state, and works in a slow-release scene with rated power and below. In the charging mode, the charging pile continuously shunts the main bridge arm power device by using the additionally arranged shunting diode, so that the current stress and thermal stress of the main bridge arm power device are reduced; and through a self-adaptive modulation strategy of three-level / two-level modulation mode switching, the loss distribution of a power device is optimized, the active power output capability of the charging pile in a charging mode is improved, the fast charging operation of the charging pile with over-rated power is realized, the equipment capacity utilization rate of the charging pile is fully excavated, and the method has remarkable engineering application value.

The invention relates to a distributed photovoltaic power station main converter and a control method thereof, 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; 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. And one end of a direct-current inductor of the Buck-Boost converter is connected with the midpoint O. The T-type three-level converter adopts PI control and a carrier pulse width modulation strategy to realize alternating current side current harmonic wave minimization of the T-type three-level converter; the Buck-Boost converter adopts a PI control method to realize neutral-point potential automatic balance control. The method is small in current harmonic wave, low in cost and simple to control, and can realize quick and automatic balance of the neutral-point potential, thereby effectively coping with the influence of illumination and power grid voltage fluctuation on system control, and realizing quick and stable control of the distributed photovoltaic power station.

The invention relates to the technical field of parallel three-level converter control, and provides a parallel three-level converter model prediction control method and system, and the method comprises the steps: enabling a parallel three-level converter to be modeled as a series connection of an equivalent voltage source and an equivalent filter inductor according to the Thevenin theorem, enabling the parallel three-level converter to be equivalent to a five-level converter, and enabling the parallel three-level converter to be connected in parallel; a three-layer optimization control strategy is adopted; in the first layer, a candidate vector closest to a reference voltage vector is selected as an optimal five-level basic vector so as to track a parallel total output current; in the second layer, a redundant five-level voltage vector is selected to balance the neutral-point voltage; and in the third layer, selecting the candidate switching state which enables the circulating current suppression value function to be the minimum as the optimal redundant three-level switching state so as to suppress the circulating current. The method can effectively reduce output current harmonics under low switching frequency, and balance of neutral-point voltage and effective suppression of circulating current are realized to ensure safe and stable operation of a parallel converter system.

A level shifter includes: a low voltage domain configured to output non-overlapping first and second current pulses based on opposite edges of a logic input signal; and a high voltage domain comprising a latch and a current mirror circuit configured to mirror the non-overlapping first and second current pulses such that the latch is set when the first current pulse is active and reset when the second current pulse is active. The current mirror circuit includes a first mirroring path for the first current pulse and a second mirroring path for the second current pulse. The level shifter has a common mode slew current that is added to the non-overlapping first and second current pulses. The first mirroring path and the second mirroring path are cross-coupled such that the common mode slew current is reduced or cancelled before the non-overlapping first and second current pulses are input to the latch.

The invention relates to the technical field of modular multilevel converters, and provides an MMC fault diagnosis method, system and device based on a sorting voltage-sharing algorithm. Comprising the steps that according to measurement data of the modular multilevel converter, a theoretical value and an actual value of bridge arm voltage of the modular multilevel converter are obtained through calculation, the theoretical value and the actual value are compared with a first alarm threshold value, and a corresponding bridge arm fault and a fault type are determined; calculating the number of fault sub-modules according to the bridge arm voltage actual value and the bridge arm voltage theoretical value; judging the switching number of the fault bridge arm sub-modules, and controlling and adjusting the bridge arm sub-modules to be switched on according to the fault type and the number of the fault sub-modules; and calculating a capacitor voltage minimum difference value, comparing the capacitor voltage minimum difference value with a second alarm threshold value, and determining a fault sub-module. According to the multi-tube fault diagnosis method, the problem that the fault positioning performance is poor under the light load working condition is solved, and the sub-module positioning performance in the full power range is improved.

The invention provides a bidirectional level converter and electronic equipment, and relates to the technical field of analog integrated circuits, the bidirectional level converter comprises a first port, a second port and a conversion circuit arranged between the first port and the second port; the first port comprises a first input / output port and a first reference level port; the second port comprises a second input / output port and a second reference level port; the conversion circuit comprises a first Schmidt comparator, a clamping circuit, a pull-up module, a pull-down module and a second Schmidt compartment.The bidirectional level converter and the electronic equipment have the advantages that under the condition that an input signal is converted from a high signal to a low signal, driving of an input stage does not need extremely high driving capacity, input and output are in an isolated state, and the conversion efficiency is improved; and the load size of the output stage has no influence on the driving capability of the input stage, so that the integrity of signals can be maintained, the system design is more flexible, and meanwhile, the circuit can adapt to more application scenes.

A level shifter according to an embodiment and a display device including the same are disclosed. A level shifter includes a first logic circuit configured to receive a mode selection signal of a first voltage level for selectively driving first and second light-emitting elements that emit light at different viewing angles of a pixel circuit from a timing controller and transmit the mode selection signal; and a second logic circuit configured to convert the mode selection signal of the first voltage level into a mode selection signal of a second voltage level higher than the first voltage level and output the converted mode selection signal of the second voltage level to the pixel circuit.

The invention relates to a three-level SVG multistage WARD equivalent modeling method based on an L / C constant admittance model. An ANPC type three-level converter model is an important part of various types of power electronic equipment, and is applied to scenes such as a three-level static var generator (SVG) and the like. In small-step offline simulation, an existing simulation modeling technology cannot consider precision and efficiency at the same time. Aiming at the problem that the simulation speed is extremely low in an offline simulation platform, a three-level SVG electromagnetic transient simulation acceleration model equivalent to a multi-stage nested fast simultaneous solution algorithm is provided based on a device Norton equivalent circuit. Firstly, an L / C equivalent constant admittance model is used for carrying out equivalent processing on a switching device, first-time WARD equivalence is carried out, then an equivalent circuit is connected with other transformer and filter inductance circuit parts, WARD equivalence is carried out again, and finally a Norton form equivalent circuit is formed.

The invention discloses an MMC AC-DC admittance model establishment method considering AC frequency and related equipment, and the method comprises the steps: obtaining a main circuit small signal model, a voltage loop small signal model and a current loop small signal model of a modular multilevel converter, and carrying out the rewriting of the models through a harmonic state space method, according to the method, the working condition of alternating-current side rated operation frequency change is considered, the method is suitable for stability analysis of a flexible direct-current transmission sending-out system considering frequency change of a new energy collection system, then unknown numbers in a rewritten model are obtained based on a steady-state theory solving method, and finally a modular multilevel converter mixed admittance model is established. The method is not influenced by AC side and DC side power grid admittance, is only determined by a steady state working point, a control structure and converter parameters of the modular multilevel converter, and better meets the requirements of fully protecting user privacy and commercial confidentiality during system stability analysis.

A system may include a multi-level power converter comprising a power inductor and a plurality of switches and a controller configured to control the plurality of switches such that the multi-level power converter generates a regulated output voltage from an input voltage to the multi-level power converter, monitor an average inductor current through the power inductor, and operate the multi-level power converter in one of a continuous conduction mode and a discontinuous conduction mode based on the average inductor current.

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.

A voltage source multi-level converter topology and a control method thereof. The voltage source multi-level converter topology includes two groups of half-bridge circuits, two groups of flying capacitors and a plurality of switches. Each group of half-bridge circuits include two direct-current connection ends, and outputs of the two groups of half-bridge circuits are both connected, through a switch, to the two groups of flying capacitors that are in series. A neutral point of a connection between the two groups of flying capacitors is connected to an alternating-current end through two switches that are in reverse series, and an overall positive electrode and an overall negative electrode of the two groups of flying capacitors that are in series are respectively connected to the alternating-current end through switches.

Embodiments disclose a level shifter including a logic unit configured to receive timing data and channel data and output an edge signal and a channel signal at a time point defined in the timing data, and a channel selection unit configured to select at least one channel from among a plurality of connected channels according to the channel signal and transmit the edge signal, and a display device including the same.

A controller for a multi-level power converter that utilizes a look-up-table (LUT) in combination with a fast flash analog-to-digital converter (ADC) circuit to implement a complex set of control states for the multi-level power converter. Since the set of control states can be pre-processed, a LUT is very well suited for such selecting such control states. This technique can be fast because the delay is only the LUT access time, rather than the propagation delay through a complex network of combinational logic. The fast flash ADC has been designed to achieve all the following: high conversion speed, high resolution, small layout area, low power, and the ability to meet the requirements for properly balancing fly capacitor voltages in a multi-level converter cell.

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.

The invention provides a hybrid modular multi-level grid-connected converter based on intensive redundant module multi-terminal sharing. The hybrid modular multi-level grid-connected converter comprises a three-phase circuit topology; the three-phase circuit topology comprises three same single-phase topologies, and each single-phase topology comprises an upper bridge arm, an upper bridge arm inductor, an upper bridge arm switch, a middle module, an alternating current bridge arm, a lower bridge arm, a lower bridge arm inductor and a lower bridge arm switch; the intermediate module comprises a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube and a direct current capacitor. According to the invention, by introducing the intermediate module, the fault-tolerant capability is provided when the upper and lower bridge arm sub-modules and the AC bridge arm sub-module have faults. Compared with a traditional redundant module configuration mode, the topology has the advantages that the utilization rate of the redundant module is greatly improved, and the operation reliability of the multi-level converter is improved.

The invention discloses a three-level converter two-dimensional optimization model prediction control method and device. The method comprises the following steps: calculating a reference voltage vector and a phase angle of an inverter at a moment k through a dead-beat principle; the method comprises the following steps: dividing a voltage vector region of a three-level converter into six large sectors based on a two-dimensional optimization principle, and dividing each large sector into six small sectors; taking the optimal voltage vectors corresponding to the small and medium sectors in each large sector as preparatory optimal voltage vectors, and making a preparatory optimal voltage vector corresponding table of each sector; selecting a preparatory optimal voltage vector corresponding to the reference voltage vector at the k moment by using the preparatory optimal voltage vector corresponding table of each sector; determining an optimal voltage vector according to the prepared optimal voltage vector and the neutral-point voltage; according to the invention, on the premise of realizing neutral-point voltage balance and stable operation of the three-level converter, current ripples and calculation burden can be reduced.

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.