102 results about "Multilevel inverter" patented technology

This power conversion device includes a multilevel inverter which outputs multilevel voltages by adding / subtracting voltage of a sub inverter to / from output voltage of a main inverter. The multilevel inverter can switch between PWM operation in which plural pulses are outputted in each of positive voltage output and negative voltage output in one cycle and a pulse width is controlled, and one-pulse operation in which one pulse is outputted in each of positive voltage output and negative voltage output in one cycle, and has a current-split switching mode in which current flowing between a neutral point and the sub inverter flows through a first switch group and a second switch group provided to the main inverter and connected in parallel, in a case where the main inverter outputs zero voltage which is the potential of the neutral point, in the one-pulse operation.

The invention discloses a differential closed-loop control method and device for a dual-frequency induction heating power supply inverter, and belongs to the technical field of induction heating power supplies, and the method comprises the steps: carrying out the learning and analysis of a control frequency relation of the dual-frequency induction heating power supply inverter through a deep learning method, and determining an optimal control frequency; a multi-level inverter is used as a power supply inverter for dual-frequency induction heating; s2, according to the optimal control frequency determined in the step S1, performing differential closed-loop control on the output frequency of the multi-level inverter by adopting a control method combining PWM control and PM control; pWM and PM control parameters are dynamically adjusted through a real-time adjustment mechanism of differential closed-loop control. According to the invention, the frequency adjustment precision and the power output stability of the dual-frequency induction heating power supply inverter are improved.

The invention provides a high-voltage frequency converter control system, and relates to the technical field of power electronic control, the high-voltage frequency converter control system comprises a phase-shifting transformer, a multi-level inverter, an SPWM modulation module, a fuzzy PI current limiting controller and a virtual master-slave topology controller, the phase-shifting transformer is used for performing phase-shifting isolation on power grid input voltage and inhibiting input current harmonics; the multi-level inverter is in cascade connection with the output end of the phase-shifting transformer and used for inverting the direct-current voltage into multi-level alternating-current high voltage to be output. The SPWM modulation module is electrically connected with the multi-level inverter; the phase-shifting transformer is combined with the multi-level topology, so that the harmonic content of the input current is reduced to 1.5% or below, the standard can be met without an additional filter, the output voltage THD is controlled within 2% through the asymmetric rule sampling and tangent approximation method by the SPWM modulation technology, and motor heating and electromagnetic interference are remarkably reduced.

A conversion system includes a conversion device including a multilevel inverter configured to generate two alternating current (AC) output currents, a current sensor configured to sample a current through the multilevel inverter, or from the multilevel inverter, during a switching cycle, and a processor configure to estimate both of the two AC output currents based on the sampled current from the current sensor.

A multi-level inverter using cascaded H-bridge modules, where each module can balance its at least two charge storage elements by means of voltage equalization. Modules are arranged in series into at least one cascade inverter phase with optional center taps, and modules communicate with a control unit by being addressed over at least one serial communication bus. Additional features that can be included in embodiments are the configuration of modules to react to multiple specific addresses in order to increase the maximum output voltage slew rate, metal circuit breaking springs to provide fusing within modules, and the ability to interconnect multiple physically distinct inverters into a single unit. This inverter is predominantly intended for electric vehicle applications, and the optional incorporation of a switching array allows the possibility for power transfer to or from a wide range of voltage sources including other inverters.

The invention provides a three-phase-in-one type parallel multi-level inverter and a motor simulator, the three-phase-in-one type parallel multi-level inverter comprises three phases of inverter circuits, each phase of inverter circuit comprises a plurality of bridge arm branches which are connected in parallel with a direct current bus power supply, the number of the bridge arm branches is equal to that of the inverter circuits, and each bridge arm branch comprises two switching devices which are connected in series; the number of the three-phase one-in-one type magnetic rings is equal to that of the bridge arm branches in any phase of inverter circuit, and each three-phase one-in-one type magnetic ring is formed by spirally winding three wires on the choking coil, one end of each of three wires of each three-phase-in-one magnetic ring is connected with the midpoint of one bridge arm branch in one phase inverter circuit, and the other end of each of the three wires forms a current output end of a corresponding phase according to an in-phase connection mode. According to the inverter provided by the invention, the cascade coupling inductor topological structure of the existing motor simulator is changed, and the problem that the high-frequency circulating current is increased along with the increase of the number of the branches is effectively solved.

An exemplary Cascaded H-bridge or Modular Multilevel Converter / Inverter are disclosed that employ a H-bridge cell or half-bridge cell that includes a linking switch additionally employed between two H-bridge cells, i cell and i+1 cell, to allow a parallel number of cells to operate together. Each of the H-bridge cells includes the standard four switches and additionally the linking switch between two H-bridge cells. The system can beneficially have improved system conversion efficiency due to better DC energy source utilizations, e.g., for improved efficiency of converters that convert DC energy to AC energy. The cascading H-bridge cells (or half-bridge cells) can be configured as a charge pump converter, bidirectional 3-phase inverter, among other topologies.

The invention provides a high-efficiency micro energy storage module based on an intelligent energy management system and a control method, the high-efficiency micro energy storage module comprises an energy storage unit, a power conversion unit, a dynamic equalization unit, an intelligent control unit and a communication interface unit, the energy storage unit is composed of multiple groups of battery clusters, each group of battery clusters comprises battery modules connected in parallel, bidirectional DC / DC converters are configured between the modules so as to realize inter-cluster energy dynamic balance; the power conversion unit comprises a bidirectional DC / DC converter and a multi-level inverter, and is used for realizing electric energy bidirectional conversion between a DC bus and an AC power grid / load. According to the invention, through the dynamic equalization design of the multiple groups of battery clusters and the bidirectional DC / DC converter, efficient energy distribution between the battery packs is realized, and capacity loss caused by inconsistency between the clusters is reduced; a multi-level inverter and a bidirectional DC / DC converter are integrated, so that the DC / AC electric energy conversion efficiency and the waveform quality are improved; the non-dissipative equalization technology based on SOC / SOH dual monitoring reduces energy loss and prolongs the service life of the battery.

The invention discloses a control method and device of a braking device and the braking device, which are used for reducing the cost of a braking assembly of a multi-level inverter. The braking device comprises a first braking assembly, a second braking assembly and at least one third braking assembly. The first brake assembly, the at least one third brake assembly and the second brake assembly are connected in series; the first brake assembly is connected with a first bus capacitor in the inverter in parallel, the second brake assembly is connected with the last bus capacitor in the inverter in parallel, and each third brake assembly is connected with two bus capacitors in the inverter in parallel; the first brake assembly and the second brake assembly comprise bridge arms, the upper bridge arm of the first brake assembly and the lower bridge arm of the second brake assembly are diodes, and the diodes are connected with a brake resistor in parallel; each third brake assembly comprises a first bridge arm and a second bridge arm which are connected in series, a lower bridge arm of the first bridge arm and an upper bridge arm of the second bridge arm are diodes, and at least one brake resistor is connected between the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm in parallel.

The present application belongs to the field of power electronics technology, and specifically discloses a voltage compensation method and device for a cascaded multi-level inverter. In the present application, the predicted value of the output current of each H-bridge inverter module in the cascaded multi-level inverter is used to compensate the turn-on angle and turn-off angle of each H-bridge inverter module respectively, and the phase shift control signal of each switching device in the H-bridge inverter module is distributed according to the compensated turn-on angle and turn-off angle, thereby effectively compensating for the PWM voltage distortion caused by the dead zone effect and the switch parasitic capacitance effect. In addition, the present application does not need to detect the output current of the H-bridge inverter module, eliminating the current detection hardware and optical fiber communication delay time. In the high-frequency cascade topology, the low-order harmonics introduced by the dead zone effect and the switch parasitic capacitance effect can be effectively suppressed, significantly improving the waveform quality.

The present invention relates to a method for controlling an electrical system comprising a battery (2) comprising a distributed multilevel inverter architecture formed by current lines (LT1, LT2, LT3) consisting of series-connected electrochemical modules comprising H-bridges. The method relates to DC fast charging. According to the invention, the method comprises controlling electrochemical modules of the battery (2) so as to generate a DC voltage wave across the terminals of each current line (LT1, LT2, LT3) based on a controlled selection of the series-connected modules, carrying out state-of-charge balancing of at least one line with respect to another line from among the three lines, configuring a set of power contactors so as to connect the three lines in parallel for connection to a charging interface (3), and carrying out parallel DC charging of the three lines using the source.

The present invention relates to a method for controlling a polyphase electrical system comprising a battery with a distributed multilevel inverter, the method comprising at least one charging configuration of the battery (BAT) comprising the following simultaneously controlled steps of generating a first DC voltage at the output of a diode module (RD) from one current line (LT1) among the three lines (LT1, LT2, LT3) during which the elementary modules (MCLk) of the line (LT1) are controlled as a function of a first reference setpoint, and charging with AC voltage the cells (CLK) of the elementary modules (MCLk) of the two other current lines (LT2, LT3) among the three lines (LT1, LT2, LT3) during which the elementary modules (MCLk) of the two other lines (LT2, LT3) are controlled as a function of a second reference setpoint synchronized with an AC voltage of an extended power supply network (RES). The invention applies to electrified vehicles and to stationary storage systems.

The present invention discloses an integrated boost switched-capacitor multilevel inverter and its control method. The inverter is composed of a DC power supply U in , an inductor L, three capacitors C1 to C3, eight switching tubes S1 to S8, and two diodes D1 to D2. By controlling the duty cycles of S5 and S6 to be equal, the charging and discharging times of the inductor L can be made symmetrical, so that the voltage of the capacitor C1 is equal to the voltage of the DC power supply U in . Then, by controlling the drive control logic of all the switching tubes, the capacitor C1 and the DC power supply can be connected in series to charge the capacitors C2 and C3 respectively, and finally the inverter can generate a voltage gain of 4 times and output levels of ±4U in , ±3U in , ±2U in , ±U in and 0. Compared with the existing multilevel inverters, the integrated boost switched-capacitor multilevel inverter of the present invention has a simpler circuit structure, fewer switching tubes, higher boost ability, and capacitor voltage self-balancing ability.

The present invention relates to the technical field of multilevel inverters, and specifically relates to a modulation method for a multilevel inverter with active control and common-mode voltage suppression. This method changes the sector division method based on the SVPWM space vector diagram, determines the large sectors and small regions by calculating the amplitude and angle of the reference vector; synthesizes the virtual vectors required for each sector based on the virtual vector synthesis principle; selects different virtual vector synthesis schemes based on the neutral point voltage deviation; calculates the action time of the virtual voltage vector according to the volt-second balance equation and distributes it to each basic voltage vector. The present invention can perform neutral point voltage balance control for any large sector and small region, and all controls are implemented through software without adding any hardware facilities, greatly reducing the control cost.

This multilevel inverter can suppress a voltage drop of a bootstrap circuit and sets one cycle of a carrier signal as a control cycle. In sixth processing, a control device (6) calculates a first total time of a first switching state, a second total time of a second switching state, and a third total time of a third switching state in a predetermined cycle. In the sixth processing, within one cycle of a carrier signal having a cycle of the same length as the total time of the first total time, the second total time, and the third total time, a zero vector, a voltage vector of twice the magnitude, a second voltage vector, and a third voltage vector are rearranged so as to achieve the order of the first switching state, the second switching state, the third switching state, the second switching state, and the first switching state, or the order of the third switching state, the second switching state, the first switching state, the second switching state, and the third switching state, while the times of the same switching states are uniformly distributed.

The present invention relates to a method for controlling an electrical system comprising a battery (2) with a distributed multilevel inverter architecture formed by current lines (LT1, LT2, LT3) made up of electrochemical modules connected in series and including H-bridges. The method relates to rapid DC charging. According to the invention, the method comprises controlling the electrochemical modules of the battery (2) so as to generate a DC voltage waveform across each current line (LT1, LT2, LT3) from a controlled selection of said series-connected modules, balancing the state of charge of at least one line with respect to another line among said three lines, configuring a set of power contactors so as to connect said three lines in parallel for connection to a charging interface (3), and parallel charging said three lines with DC voltage from the source. Figure 1.

A multi-level inverter using cascaded H-bridge modules, where each module can balance its at least two charge storage elements by means of voltage equalization. Modules are arranged in series into at least one cascade inverter phase with optional center taps, and modules communicate with a control unit by being addressed over at least one serial communication bus. Additional features that can be included in embodiments are the configuration of modules to react to multiple specific addresses in order to increase the maximum output voltage slew rate, metal circuit breaking springs to provide fusing within modules, and the ability to interconnect multiple physically distinct inverters into a single unit. This inverter is predominantly intended for electric vehicle applications, and the optional incorporation of a switching array allows the possibility for power transfer to or from a wide range of voltage sources including other inverters.

The invention discloses a control method of a multi-level inverter, a motor driving system and a readable storage medium. The method comprises the following steps: acquiring a system state of the multi-level inverter at a moment k; according to the system state, approaching the nonlinear dynamic state of the inverter system through a neural network; according to the non-linear term prediction value, combining a prediction model of the inverter system to perform system state prediction, and obtaining current prediction values corresponding to different inverter switching states at the k + 1 moment; according to the current predicted value at the k + 1 moment, a current predicted value corresponding to the k + 2 moment is obtained through a system control law; and based on the current predicted values at the k + 1 moment and the k + 2 moment under different inverter switching states, combining the current reference value at the k + 1 moment, evaluating all possible inverter switching states by using a cost function, selecting an optimal switching state which enables the cost function to be minimum, and applying the optimal switching state to the multi-level inverter. According to the method, high-precision control of the multi-level inverter without depending on a precise model is realized.

A control device (50) is for a multi-level inverter (30, 70). The multi-level inverter comprises: a plurality of capacitors (21, 22, 71 to 74) connected in series, and a plurality of switches (SUH to SWL, QU to QW, Su1 to Sw4, S1 to S8) electrically connected to at least one of the plurality of capacitors and at least one of the plurality of windings (13U to 13W) of the motor (10). The control device controls the plurality of switches to cause the multi-level inverter to output one of a plurality of voltages that can be output using a series connection element of the plurality of capacitors. The series connection element of the plurality of capacitors can be connected in parallel to a power source (20).An electronic device (40, 41) can be connected in parallel to at least one of the target capacitors, which is a part of the plurality of capacitors. The control device comprises a determination unit that determines whether a supplyable current value to the electronic device is smaller than a required current value of the electronic device, and a control unit that, when it is determined that the supplyable current value is smaller than the required current value, controls the plurality of switches such that the current flowing in the plurality of windings becomes larger than when it is determined that the supplyable current value is equal to or larger than the required current value.

A power conversion system includes a power converter including a plurality of switches, one or more capacitors, and a charging connector, wherein the power converter is configured to operate in each of a two-level inverter mode, a three-level inverter mode, a two-level converter mode, a three-level converter mode, an AC-DC onboard charger (OBC) mode, and a DC-DC boost converter mode.

The invention discloses a bidirectional multi-mode hybrid multilevel inverter circuit and a battery energy storage system, the inverter circuit comprises a controller, a power frequency commutation and filter circuit, a controller and a plurality of batteries and power units which are correspondingly and electrically connected, the batteries and the power units are divided into two groups, the output of each group of power units is cascaded to form a unipolar multi-level step wave bus; the power frequency commutation and filter circuit comprises a power frequency commutation circuit and a filter circuit, the power frequency commutation circuit is composed of a full-bridge topology, and the filter circuit is composed of an AC filter inductor and an AC filter capacitor; the controller samples an AC side signal, controls the logic sequence of each power unit and a switching tube of the power frequency commutation circuit, and controls the active equalization of the battery and the bidirectional electric energy conversion of the energy storage system. Conversion efficiency can be improved, switch power consumption and size can be reduced, and global power supply and consumption requirements can be met.

A vehicle includes an inverter having a power module. The power module includes a high side bus, a low side bus and an alternating current (AC) output bus. The high side bus includes a first switch, wherein a high side current is configured to flow through the first switch in a first direction. The high side bus is disposed in a plane. The low side bus includes a second switch, wherein a low side current is configured to flow through the second switch in the first direction. The low side bus is parallel to the high side bus. The alternating current (AC) output bus is parallel to the high side bus and the low side bus, wherein an output current flows through the AC output bus in a second direction opposite to the first direction.

The invention relates to the technical field of power electronic control, and particularly discloses a power regulation system of a multi-stage inverter, which is characterized in that a dynamic compensation capacitor is arranged between a pre-stage circuit and an inverter circuit to dynamically charge and discharge to eliminate power fluctuation of the multi-stage inverter and ensure that the multi-stage inverter is in a stable operation working state, and particularly, the power regulation system of the multi-stage inverter can regulate the power fluctuation of the multi-stage inverter. In addition, a control unit connected to the pre-stage circuit is arranged, the alternating current fluctuation voltage which needs to be output by the pre-stage circuit and is matched with the dynamic compensation capacitor can be accurately and reliably determined, the pre-stage circuit is controlled to provide the appropriate alternating current fluctuation voltage for the dynamic compensation capacitor, and therefore the instantaneous power requirement of the pre-stage circuit can be further lowered.

An inverter including: at least two parallel connected multi-level inverter cells for connection across a load, each cell comprising; two legs each including a complementary switch pair having two reverse-blocking switches; a DC-link inductor connecting the two legs between both switch pairs of the two legs in a h-bridge configuration, each of the four reverse-blocking switches positioned, when in an on state, to allow current to flow towards the DC-link inductor; a DC current source connected at a switch-inductor connection; a polarity control comprising a complementary switch pair, where the two cells are connected by their current sources between the polarity control switches, a state of the polarity control complementary switch pair determining direction of current through the load.

To improve the voltage balance at the DC link capacitor voltage of a multilevel inverter with a split DC link, a modulation signal (MS) with a modulation signal amplitude (A MS ) of even harmonic signals of the output voltage (U AC ) or the output current (i AC ) of the inverter (1) is calculated from the actual electrical power difference (P diff,act ) of the actual electrical power at the DC link capacitor (C DC1 , C DC2 ) and the setpoint (SP) for setting the output voltage (u AC ) or the output current (i AC ) of the inverter (1) is superimposed with the modulation signal (MS).

The invention relates to a modular multilevel fractal converter. The modular multilevel fractal converter comprises an inversion module, a harmonic generation module and a fractal connector module. The inversion module comprises a modular multi-level inverter, the modular multi-level inverter is used for outputting an alternating current signal, and the alternating current signal comprises a first harmonic signal in a higher harmonic interval; the harmonic generation module comprises at least one harmonic generation inverter; the harmonic generation inverter is used for generating a second harmonic signal according to the first harmonic signal; the fractal connector module is connected with the alternating current side of the modular multilevel inverter and the alternating current side of the harmonic generation inverter, and the output end of the fractal connector module is connected with the alternating current output port; the second harmonic signal is used to compensate the first harmonic signal within the fractal connector module. According to the invention, the switching frequency of the modular multilevel fractal converter can be reduced, and the overall output capacity of the converter can be improved.

A method of implementing a space vector pulse width modulation scheme. The method includes: mapping switching states for an n-phase, where n is an integer, multi-level inverter onto a two-dimensional hexagonal space vector diagram; identifying redundant vectors in the space vector diagram and removing redundant vectors associated with a common mode voltage current contribution of more than a predetermined threshold; identifying a location in the space vector diagram of a voltage reference vector; identifying a sector of the space vector diagram defined by four vectors within which the voltage reference vector is located; and determining duty cycles and switching states associated with the four vectors to synthesise the voltage reference vector.

The invention discloses a multi-level inverter topological structure, a control method thereof and a multi-level inverter, and relates to the technical field of voltage conversion. The circuit comprises a topology module and an H-bridge circuit coupled with the topology module. The topology module comprises a first DC voltage source, a DC voltage source group and a switch tube assembly. The direct-current voltage source group is coupled with the first direct-current voltage source to form a voltage loop. The direct-current voltage source group comprises at least two cascaded target direct-current voltage sources. And the switching tube assembly is embedded in the voltage loop, controls a current conduction path between the first direct current voltage source and each target direct current voltage source, and is used for adjusting a voltage value input to the H-bridge circuit from the voltage loop. A multi-level inverter topological structure can be formed by adopting a direct-current voltage source, a switch tube and an H-bridge circuit, a higher voltage level and more levels are expanded through cascade connection of topological modules, and the complexity and the production cost of the multi-level inverter topological structure are reduced.

This invention discloses a single-supply boost multilevel inverter, including a DC power supply V. D Inductor L1, inductor L2 and module SM i (i = 1…2N); where module SM1 to module SM N Connect sequentially, module SM N+1 ~Module SM 2N Connected sequentially; wherein, modules SM1 to SM N Connect sequentially, adjacent modules SM1 to SM2. N A switching transistor S is connected between them. j (j = 1, 2, ..., N-1); Module SM N+1 ~Module SM 2N Connect sequentially, adjacent modules SM N+1 ~Module SM 2N A switching transistor S is connected between them. j (j = N, N+1, ..., 2N-2); Module SM1 ~ Module SM N‑1 The second end is connected to modules SM2 to SM3 respectively. N The first end connection; the module SM N+1 ~Module SM 2N‑1 The second end is connected to module SM in sequence. N+2 ~Module SM 2N Connection; solves problems such as complex structure, weak boost capability, and poor capacitor voltage self-balancing capability of current multilevel inverters.

The invention belongs to the technical field of photovoltaic multi-level inverter control, and particularly discloses a single-phase household photovoltaic multi-level inverter predictive control method and system, and the method comprises the steps: respectively defining each switch combination as a positive vector, a negative vector and a zero vector according to the influence on a neutral-point voltage; a switching vector of an inverter is divided into eight sectors, a positive vector, a negative vector and a zero vector exist in each sector, and the positive vector and the negative vector have opposite influences on neutral-point voltage; in any sector, the NS vector and the PS vector take zero vectors as the head and tail vectors of the three-section type sequence; and determining a sector where a voltage vector is located based on the amplitude of the reference voltage of the inverter output line voltage, determining a candidate vector combination, calculating the duty ratio of each vector in the three-section type sequence, and generating a PWM signal for controlling the state of each switching tube. When the positive sequence vector and the negative sequence vector are switched, no extra switching loss is introduced, and the efficiency of the inverter is improved.