12 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 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.

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.

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 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 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.

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.

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.