32 results about "Multilevel inverter" patented technology

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 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.

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.

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 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.

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.

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 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.

Embodiments herein generally relate to several multilevel inverters topologies are methods of operating the same. In at least one embodiment, a multilevel converter system for driving a switched reluctance motor (SRM) is disclosed where the system comprises a front-end circuit coupled to a DC supply voltage, the front-end circuit comprising a respective plurality of switching elements and a plurality of diodes; a back-end circuit coupled to the front-end circuit, the back-end circuit comprising a respective plurality of switching elements; a plurality of phase leg circuits, each phase leg circuit corresponding to a respective phase winding of the SRM, each phase leg circuit comprising the front-end circuit entirely and a subset of the switching elements from the back-end circuit; and a controller configured to selectively control the switching elements and diodes of the front-end circuit and of the subset of the back-end circuit forming each phase leg circuit to generate a plurality of selectable voltage levels for operating the SRM in a plurality of operating modes.

A multi-phase power inverter for an electric propulsion system includes a plurality of X-type multi-level power converters arranged as solid state integrated circuits. Each X-type multi-level power converter includes a positive direct current (DC) power bus, a negative DC power bus, a first alternating current (AC) bus, a second AC power bus, a first clamping diode, a second clamping diode, a power module substrate disposed on an insulating substrate, and a heat sink adjacent a first side of the insulating substrate. The power module substrate includes a plurality of semiconductor switches, each semiconductor switch including a plurality of lateral semiconductor dies, each lateral semiconductor die having a gate control terminal. The plurality of semiconductor switches, the first clamping diode, and the second clamping diode are coplanar with the DC power supply terminal on one side of the X-type multi-level power converter and the auxiliary and output terminals disposed on opposite sides.

The application discloses a multi-level inverter control method and system based on reinforcement learning sequential MPC, and relates to the technical field of power electronics control, and comprises the following steps: a three-layer sequential optimization structure of current tracking-flying capacitor voltage balance-neutral point potential voltage balance is constructed in turn; a multi-objective reward function is designed by taking system state as observation input, taking current tracking tolerance boundary and flying capacitor voltage balance tolerance boundary as action output, so that dynamic balance of current tracking, flying capacitor voltage and neutral point voltage is realized; multiple control targets of optimized current tracking, flying capacitor voltage balance and neutral point potential voltage balance are optimized, and each layer is independently optimized and controlled; meanwhile, based on autonomous learning of offline reinforcement learning, optimization of multi-objective tolerance boundary values is realized, and the key problems of low artificial parameter adjustment efficiency and existing parameter setting blind area in a multi-objective system are solved.

A control unit replaces one first voltage vector out of two first voltage vectors with a zero vector and a second voltage vector. The two first voltage vectors belong to a plurality of voltage vectors, each have a reference magnitude, and are located closest to a command voltage vector. The zero vector is combination of potential levels at respective third connection nodes of a inverter circuits as high as a potential at a negative electrode. The second voltage vector has the same direction as, and twice as large a magnitude as, the first voltage vector. The control unit controls first to fourth gate drivers within a predetermined control cycle to make a synthetic vector of a voltage vector included in the plurality of voltage vectors but the first voltage vectors, the other first voltage vector, the zero vector, and the second voltage vector equal to the command voltage vector.

A dual multi-level inverter topology with reduced switch count and small DC-link capacitor is provided. The inverter topology provides multi-level inverter operation without requiring a neutral point connection that is commonly present in a stacked capacitor topology (for example, a topology including two capacitors).

In the present invention, a voltage drop in a bootstrap circuit can be suppressed, and one period of a carrier signal is set as a control period. In a sixth process, 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 prescribed period. In the sixth process, within one period of a carrier signal having a period 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 having twice the magnitude, a second voltage vector, and a third voltage vector are reordered so as to be in 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 in the order of the third switching state, the second switching state, the first switching state, the second switching state, and the third switching state, and time for the same switching state is allocated equally.

The application discloses a power balance modulation method suitable for an n-unit cascaded H-bridge multilevel inverter and belongs to the PWM technical field of multilevel converters. The method comprises the following steps: setting n carriers equal in number to the number of H-bridge units, equal in frequency and equal in amplitude; in the positive half cycle of a modulation wave, comparing the modulation wave with the n carriers to generate a first PWM signal for controlling the left side bridge arm of each unit; in the negative half cycle of the modulation wave, comparing the modulation wave with the n carriers to generate a second PWM signal for controlling the right side bridge arm of each unit; wherein the carrier is periodically cycled in the time domain according to a preset rule, so that the corresponding relationship between each H-bridge unit and each carrier is periodically rotated, thereby balancing the output power of each H-bridge unit without changing the output voltage waveform. The application can realize power balance in one reconstructed carrier cycle, effectively solves the power imbalance problem of the traditional IPD-PWM, and maintains the excellent harmonic characteristics.

The wireless electric energy transmission system of the PMM-based multi-level inverter comprises a controller, a driving circuit, a sampling circuit, a direct-current voltage source, a flying capacitor type n-level inverter circuit, a transmitting end compensation circuit, a transmitting coil, a receiving coil, a receiving end compensation circuit, a diode rectifying circuit, a direct-current side capacitor and a load. N is a natural number larger than 2, the direct-current voltage source is connected with the flying capacitance type n-level inverter circuit, and the midpoint of a bridge arm of the flying capacitance type n-level inverter circuit is connected with the transmitting end compensation circuit. The transmitting end compensating circuit, the transmitting coil, the receiving coil, the receiving end compensating circuit, the diode rectifying circuit and the direct-current side capacitor are sequentially connected, the direct-current side capacitor is connected with a load in parallel, the two ends of the flying capacitor are connected with the input end of the sampling circuit, and the output end of the sampling circuit is connected with the input end of the controller. The output end of the controller is connected with the input end of the driving circuit, and the driving circuit drives the flying capacitor type n-level inverter circuit. A corresponding method is also disclosed.

The application discloses a photovoltaic grid-connected inverter system and a control method based on discontinuous modulation, and relates to the technical field of multilevel inverter control. The method comprises the following steps: obtaining a three-phase sinusoidal modulation wave of a multilevel inverter, constructing a square wave signal and adjusting the amplitude of the square wave signal, and dividing a clamping interval according to the intersection of the square wave and the three-phase sinusoidal modulation wave; based on midpoint balance and resonance suppression, the square wave signal is subjected to compensation voltage superposition; a control threshold for presetting the control midpoint voltage fluctuation range is determined, and the priority of controlling the midpoint voltage and suppressing common-mode resonance is determined; the square wave compensation voltage is adjusted according to the priority; the three-phase sinusoidal modulation wave and the square wave after the compensation voltage adjustment are compared, a DPWM common-mode modulation wave is determined, and a DPWM modulation wave is obtained, and the switching tube is controlled according to the DPWM modulation wave. The application can realize the multi-objective optimization control of midpoint voltage balance, common-mode resonance suppression and reduced switching loss.

A multi-phase power inverter for an electric propulsion system including a plurality of X-type multilevel power converters arranged as solid-state integrated circuits. Each X-type multilevel power converter includes a positive direct current (DC) power bus, a negative DC power bus, a first alternating current (AC) bus, a second AC power bus, a first clamping diode, a second clamping diode, a power module substrate disposed on an insulating substrate, and a heat sink adjacent to a first side of the insulating substrate. The power module substrate includes a plurality of semiconductor switches, each including a plurality of lateral semiconductor dies each having gate control terminals. The plurality of semiconductor switches, the first clamping diode, and the second clamping diode are coplanar, with the DC power terminals on one side of the X-type multilevel power converter, and the auxiliary and output terminals disposed on the opposite side.

The invention belongs to the technical field of perovskite photovoltaic module grid connection, and relates to a multi-level low-leakage perovskite photovoltaic module inversion system, which comprises a perovskite photovoltaic group string, a blocking switch module, a common ground module, a multi-level inverter module, a modulation controller module, a filtering module and a grid connection interface, nine stages of multi-level output assemblies which are sequentially connected in series are arranged in a multi-level inverter module, each stage of multi-level output assembly is composed of a switched capacitor unit and a flying capacitor unit which are connected in series, and each switched capacitor unit is composed of two power voltage dividing switches and a voltage dividing capacitor. Each flying capacitor unit is composed of two power balancing switches and a flying capacitor, the modulation controller module is respectively communicated with the power voltage dividing switch and the power balancing switch to control on-off of the power voltage dividing switch and the power balancing switch, a voltage sinusoidal waveform is output, and the filtering module is used for suppressing harmonic waves of the output voltage. The system leakage current is reduced, the system life is prolonged, and the system generating capacity is improved.

A vehicle system includes a first battery pack connected to a second battery pack via T-type multi-level inverter. The multi-level inverter has a plurality of inverter legs, with each inverter leg being arranged in a T-type topology. A motor is connected to the multi-level inverter and a controller is connected to the motor and the multi-level inverter. The controller including a memory storing instructions configured to cause the controller to control the multi-level inverter as a direct current (DC)-DC converter such that a circulating current passes through the motor, the first battery pack and the second battery pack.

The present application relates to a kind of optimal switching vector universal determination method in arbitrary multi-level inverter power supply direct torque control system, belong to multi-level inverter control field.The method is determined by sector judgment, level effect area, limiting amplitude generation, k time relative increment determination, k time actual increment calculation, optimal origin vector determination and k time optimal voltage vector determination link section constitute.The present application can be applicable to the direct torque control system of arbitrary multi-level circuit topology power supply, improves the optimal switching vector determination speed of constructing complex multi-level circuit;The present application can also add specific multi-level circuit topology constraint condition according to the optimal switching vector set determined, and the optimal switching vector of the output of specific multi-level circuit is quickly generated.

A system of power modules for a multi-level inverter for an electric vehicle. A system includes an inverter for converting DC power from a battery to AC power to drive an electric machine, where the inverter includes: a power module including: a positive DC power tab; a negative DC power tab; an AC power tab; a first neutral power tab; a second neutral power tab, where the first and second neutral power tabs are on opposite sides of the positive and negative DC power tabs; a first switch electrically connected to the positive DC power tab and the AC power tab; a second switch electrically connected to the negative DC power tab and the AC power tab; and one or more switches electrically connected to the AC power tab and one or more of the first or second neutral power tabs.

The application discloses a current phase estimation method and a dead-time compensation method of a cascaded multi-level inverter, and belongs to the technical field of power electronics. d When the current phase angle is, the dead-time error voltage u d of the H-bridge submodule is determined as 0; when the current phase angle is, the dead-time error voltage u DC of the H-bridge submodule is determined as d ; when the current phase angle is, the dead-time error voltage u d of the H-bridge submodule is determined as on ; when the current phase angle is, the dead-time error voltage u off of the H-bridge submodule is determined as DC ; Fourier expansion coefficients of fundamental wave components of ideal output voltages u idl and u d of the H-bridge submodule are solved respectively, then the Fourier expansion coefficients are added, and the Fourier coefficients of the fundamental wave components of the output voltage of the cascaded multi-level inverter are accumulated to calculate a phase lag angle; and according to the estimated current phase angle, the turned-on angles of the H-bridge submodules after compensation are calculated. The application does not depend on current detection, and can effectively inhibit low-order harmonics introduced by the dead-time effect.

A system for a capacitor assembly of a multi-level inverter for an electric vehicle. The invention provides a system comprising an inverter for converting DC power from a battery to AC power to drive an electric machine, where the inverter comprises: a capacitor assembly comprising: a first set of capacitors connected to one or more power modules, wherein the first set of capacitors is used when the one or more power modules operate as a two-level inverter; and a second set of capacitors connected to the one or more power modules, where the second set of capacitors is used when the one or more power modules operate as a three-level inverter or as the two-level inverter.

A charger for an electric vehicle includes an NPC multilevel inverter circuit that outputs a driving current to a travel motor. In at least one leg, an upper clamp is an upper switching clamp configured to perform switching operation, and a lower clamp is a lower switching clamp configured to perform switching operation. One of a pair of power lines through which electric power for charging is transmitted is coupled to a connection point of the upper switching clamp and an upper arm. The other one of the power lines is coupled to a connection point of the lower switching clamp and a lower arm. Moreover, a controller is configured to drive the multilevel inverter circuit to step up the electric power for charging by charge pump operation using two capacitors.

The utility model relates to a cascade multi-level inverter topological structure based on direct current coupling thyristors, and belongs to the technical field of power electronic converters. Comprising N H-bridge modules and N DC / DCamp, the H-bridge module comprises four IGBTs (Insulated Gate Bipolar Transistors), the PV panel module comprises N-1 bidirectional switch bridge arms and a power grid filter inductor Lf; the DC / DC amp; the PV panel module comprises a photovoltaic panel, a dual active bridge, a photovoltaic side capacitor Cpvj and a direct current side capacitor Cdcj; the bidirectional switch bridge arm comprises two thyristors Tj1 and Tj2 which are reversely connected in parallel; one end of the power grid filter inductor Lf is connected with the positive electrode of the power grid voltage source vg, the other end of the power grid filter inductor Lf is connected with the midpoint of the S11 and the S12 in the first H-bridge module, the N H-bridge modules are cascaded in sequence, and the midpoint of the SN3 and the SN4 in the Nth H-bridge module is connected with the negative electrode of the power grid voltage source vg. According to the invention, fault ride-through operation can be realized under the condition that the direct-current side voltage sensor has a fault, and large-range module power mismatch can be tolerated.

The application provides a kind of multilevel inverter power device fault diagnosis method, it is characterized in that, using feedforward convolution-pooling network and auxiliary neural network to the operating mode of each phase of multilevel inverter is identified, obtains diagnostic result, wherein, the weight and bias parameter learned by auxiliary neural network is migrated to the convolution kernel of feedforward convolution-pooling network, to share the learning ability of auxiliary neural network, make feedforward convolution-pooling network have the feature identification of the operating mode of multilevel inverter.Using the diagnostic method proposed in the application, the inherent problems of traditional circuit model method and data-driven method, i.e., the contradiction between model dependency and diagnostic speed, are effectively improved.The diagnostic network proposed in the application has high diagnostic precision while reducing the demand for training samples and speeding up signal processing by sharing learning ability and simplifying convolutional neural network structure, which is helpful for online fault diagnosis.

We provide a multi-level inverter that can lower the voltage rating of the switch. [Solution] The multilevel inverter (24) receives a multilevel voltage formed based on the voltages output from multiple series-connected batteries (26a, 26b) and switches the output voltage to one of the multilevel voltages. The multilevel inverter includes multiple series-connected high-voltage switches (Su1, Su2, Sv1, Sv2, Sw1, Sw2) that receive a total voltage obtained by summing the voltages of the multiple batteries and switch between outputting and cutting off the total voltage, and multiple changeover switches (41, 42) that switch the voltage input to the multiple high-voltage switches to one of the voltages output from the terminals and connection points (CP) of the multiple batteries that is lower than the total voltage and higher than 0.

The application provides a hybrid multi-level inverter predictive control method, a discrete model predicted by a single vector model is used to establish a value function without a weight factor, and a voltage predicted when the value function minimum is used to replace a reference voltage to perform space vector modulation. A fault-tolerant control method is to establish a seven-level voltage space vector diagram, remove the coordinates lost in the space vector diagram due to bypassing the H-bridge unit due to failure, and continue to perform space vector modulation by using the remaining coordinates. The application uses single vector model prediction to reduce the calculation amount of the value function while ensuring accuracy, uses a common-mode reduction method to reduce the system common-mode voltage, so that the method can be applied in the photovoltaic industry to prevent damage to other devices caused by large common-mode voltage.