81 results about "Voltage source inverter" patented technology

The invention discloses an open-phase self-fault-tolerant control method for a phase-shift-free dual three-phase permanent magnet synchronous motor. The method can automatically adjust a current distribution relation in the case of an open-phase fault and suppress torque pulsation in combination with neutral point voltage compensation. Comprising the following steps: driving two pairs of three-phase winding modules of the phase-shift-free DTP-PMSM in parallel by adopting two two-level three-phase voltage source inverters, and providing a mathematical model of the motor; current distribution is automatically adjusted; compensating the voltage of the neutral point, and calculating the offset of the fault module; the current is redistributed to suppress the torque ripple after the fault, and the secondary oblique wave component generated by the phase failure fault is eliminated; a current loop controller is improved through dead-beat predictive control; the speed ring controller is optimally designed into an improved sliding mode controller; an improved double-loop controller system is formed by combining improved sliding mode control and dead-beat prediction control, high-gain parameters are set to improve the dynamic response performance of the system, and a new self-fault-tolerant control system is formed.

The invention discloses a double-layer MPC-based power distribution network area inverter switching control method and system, and the method comprises the steps: obtaining the operation parameters and equipment parameters of an area power distribution network, and building a voltage source type inverter system model considering the frequency fluctuation; constructing an outer-layer model, and generating an output voltage reference value of an inverter grid-connected mode and an output voltage reference value of a grid construction mode according to the operation parameters and the equipment parameters; calculating a synchronous decision signal, and switching the working mode of the inverter; calculating a parallel system bus voltage reference value and an output current reference value of the current sampling period; and constructing an inner-layer model, calculating a predicted value and a reference value of voltage and current in a next sampling period, constructing a value function cost optimization model according to a deviation degree between the predicted value and the reference value, generating an optimal switching state, and controlling the power distribution network area inverter. Dynamic response and stability are both considered, seamless switching of the voltage source type inverter is achieved, meanwhile, voltage out-of-limit is avoided, and the stability of a power system is improved.

The invention relates to a non-current sensor model prediction control method and system based on an LC filtering type voltage source inverter, and belongs to the field of inverter control. The designed sliding mode observer only needs capacitance parameters, and inductance and voltage observation errors have no influence on current observation errors. A capacitor current predicted value and a capacitor voltage predicted value are predicted by using the sliding mode observer, and the three-phase switching state of the inverter is regulated and controlled according to the predicted values. Therefore, the parameter robustness of the sliding-mode observer is high, and when the sliding-mode observer is used for controlling the inverter, the control precision is high.

The invention relates to a harmonic suppression and dynamic voltage compensation method based on a composite control series filter, and belongs to the field of power electronic technology and electric energy quality control. Harmonic current passing through a primary winding of a transformer and a sudden rising or falling signal of power supply voltage are extracted, and after the two signals are controlled and combined into a reference signal, a voltage source inverter (VSI) connected with a secondary side of the transformer in parallel shows a controllable voltage characteristic. The control parameters of the harmonic current can enable the transformer to present relatively large controllable impedance to harmonic waves, so that harmonic wave isolation is realized. In addition, the VSI compensates for the system voltage deviation by detecting the voltage drop. And finally, establishing a simulation model to verify that the series active power filter based on the control strategy can isolate harmonic waves and effectively compensate voltage deviation. Harmonic suppression and dynamic voltage compensation functions can be realized at the same time, and the power quality of a middle-high voltage system is improved.

The invention provides an active support control method for a single-phase cascaded optical storage grid-connected system, aiming at challenges caused by fluctuation, intermittency and reverse peak regulation of photovoltaic resources in a photovoltaic energy consumption process and the problem of insufficient active support capability of a micro-grid for a large power grid under the access of high power electronic equipment. The low-voltage photovoltaic units are boosted by inverter cascading, and each photovoltaic unit is equipped with stored energy to stabilize photovoltaic fluctuation. A grid-side current source inverter is controlled by a virtual synchronous generator (VSG), so that the active support of the inverter on a large power grid frequency is ensured; other voltage source inverters adopt power factor angle droop control, and an active power compensation item is introduced, so that self-synchronization between the inverters and accurate power equalization between energy storage units are ensured. Compared with a traditional control method, the method can control active power and reactive power at the same time, has frequency supporting capacity, is low in communication cost, and provides a new solution thought for the problem of large-scale photovoltaic grid connection.

A battery charging system for a hybrid electric vehicle includes: a battery, a battery management system, and a support unit. The support unit includes an electronic control unit provided with a predefined motor speed constant (S) and a predefined state of charge value (SoC). The electronic control unit receives a real-time motor speed (SRT) from one or more sensing units and a real-time state of charge value (SoCRT) for the battery from the battery management system. The electronic control unit generates one of a first activation signal and a second activation signal based on one of the real-time motor speed (SRT) and the real-time state of charge value (SoCRT) of the battery. The battery management system initiates a voltage source inverter charging mode upon generation of the first activation signal and a boost converter charging mode upon generation of the second activation signal.

This invention discloses a dual-variable symmetrical injection modulation method for a two-phase permanent magnet synchronous motor, belonging to the field of motor drive and control technology. The method includes the following steps: S1, setting motor start-up logic and soft-start parameters; S2, generating two-phase orthogonal line voltage commands; S3, dual-variable symmetrical injection; S4, PWM comparator register mapping and output; S5, periodic execution. This method requires no modification to the hardware topology of a standard three-phase voltage source inverter or the addition of additional circuit components, and can be directly deployed on existing mature hardware platforms. This allows the same three-phase inverter to be used to drive both three-phase and two-phase motors, achieving hardware platform reuse and standardization, significantly reducing system development and bill of materials costs, resulting in low hardware cost and strong versatility.

The present invention relates to a control system (20) and method for controlling the flow of current between a voltage source (22) and a multiphase motor or other application / load for controlling a multiphase motor (28). The control system includes, between each phase of the multiphase motor and the voltage source: a high-side diode (30A-C) and a high-side switch (34A-C) positioned in parallel between a positive terminal of the voltage source and the motor, wherein the high-side diode is reverse biased with respect to the positive terminal; and a low-side diode (32A-C) and a low-side switch (36A-C) positioned in parallel between a negative terminal of the voltage source and the motor, wherein the low-side diode is reverse biased with respect to the motor. The control system operates the high-side and low-side switches to provide efficient operation of the motor.

The invention discloses a zero common-mode voltage pulse width modulation method suitable for a dual three-phase permanent magnet synchronous motor. According to the combination relation between the common-mode voltage and the power device switch of the two-level voltage source inverter, the pulse duty ratio of each phase of the voltage source inverter is calculated based on a carrier pulse width modulation method, and the pulse duty ratio of each phase is adjusted in order according to the relation between the sum of the pulse duty ratios and 3, so that the sum of the adjusted duty ratios is 3. Then, on this basis, odd-even symmetrical PWM pulses are connected end to end and arranged for phase shifting based on the volt-second balance principle, so that even harmonics of common-mode voltage and phase current are eliminated. The method can effectively eliminate the common-mode voltage during operation of the permanent magnet synchronous motor, maintains the original steady state and dynamic performance, and has a good application prospect.

The application discloses a three-level inverter harmonic suppression method based on zero vector symmetrical reconstruction and spread spectrum composite modulation, and the method comprises the following steps: step 1, signal acquisition and voltage instruction acquisition; step 2, spread spectrum modulation parameter setting; step 3, basic vector action time calculation; step 4, zero vector symmetrical reconstruction of vector sequence; step 5, switch time calculation and register updating; and step 6, PWM signal generation and system closed loop operation. The application realizes full-band suppression of inverter output PWM harmonics by deeply fusing the zero vector symmetrical reconstruction technology and the spread spectrum modulation technology. The application can be applied to a permanent magnet synchronous motor driving system powered by a three-level voltage source inverter, can simultaneously suppress the PWM harmonic amplitude near the odd carrier frequency and the even carrier frequency, effectively reduces electromagnetic vibration and noise, and has extremely high application value in the field of high-power inverters and motor drives.

The application discloses a three-phase voltage source inverter, which comprises: inverter A, B and C three-phase upper and lower working bridge arms V a1 、 b1 、 c1 、 a2 、 b2 、 c2 , corresponding anti-association diodes VD a1 、 b1 、 c1 、 a2 、 b2 、 c2 , upper and lower bridge arm shunt switch devices S1 and S2, three-phase selective switch devices T a1 、 b1 、 c1 、 a2 、 b2 、 c2 in additional dynamic shunt branches; when the inverter AC side three-phase current has a phase with a maximum positive current, the T a2 、 b2 、 c2 corresponding to the additional dynamic shunt branch are turned on, and the S1 of the additional dynamic shunt branch is shunted in parallel to the phase with the maximum positive current; when a phase with a maximum reverse current exists, the T a1 、 b1 、 c1 corresponding to the additional dynamic shunt branch are turned on, and the S1 of the additional dynamic shunt branch is shunted in parallel to the phase with the maximum reverse current. The application reduces the overcurrent of the inverter working bridge arm switch device caused by AC system disturbance, and improves the operation reliability of the inverter.

The invention provides a second-order model-free predictive control method for a voltage source inverter, relates to the technical field of power electronic converter control, and solves the problem that model predictive control depends on model parameters, system parameters do not need to be considered, and only input and output of a system need to be considered. And the influence of parameter mismatch on a control system is greatly reduced. Therefore, the system has good steady-state performance, robust performance and anti-disturbance performance. The provided control scheme is economical, reliable and easy to implement.

A method of carrier-based modulation with a dual gate bidirectional switch includes the steps of receiving a sine triangle pulse width modulation (PWM) signal; converting the received sine triangle PWM signal from a voltage source inverter (VSI) input to a current source inverter (CSI) output involving vector matching; converting the CSI output to internal model control (IMG) signal pulses; generating a PWM signal for each dual gate bidirectional switches based on the IMG signal pulses; generating two gate signals for each dual gate bidirectional switch; and selectively applying a phase shift or delay between the gate signals applied to a high side of the dual gate bidirectional switch relative to a low side of the dual gate bidirectional switch.

The invention belongs to the technical field of inverters, and particularly relates to an inverter global asymptotic stability control method, a nonlinear controller and an inverter, a passivity-based three-phase voltage source type inverter double-loop controller is deduced on the basis of a passive current controller, and effective compensation for harmonic voltage is realized. In a current inner ring controller, an absolute value item of a voltage error is introduced, and the buffeting problem introduced by an inner ring sliding mode item is effectively suppressed. In the passive current inner loop controller, a nonlinear control item is introduced, the robustness of the system is enhanced, and the harmonic voltage can be effectively compensated even under 50% parameter disturbance. In addition, the controller provided by the invention only needs two control parameters, so that the system design and parameter setting process is greatly simplified.

The invention discloses a virtual two-port-based inverter impedance remodeling and network power flow control method. The virtual two-port-based inverter impedance remodeling and network power flow control method comprises a voltage source type inverter impedance remodeling method and a voltage source type inverter network power flow control method. According to the voltage source inverter impedance remodeling method, system impedance modeling is firstly analyzed, virtual two-port network parameters are designed, then a control signal is calculated and input into an original system, and impedance remodeling is completed; the voltage source type inverter network power flow control method comprises the steps of collecting data, building a line model, calculating power flow control parameters, calculating control signals, inputting the control signals into an original system, and completing power flow control. The invention discloses a virtual two-port-based inverter impedance remodeling and network power flow control method, and aims to solve the problems that parameters of existing virtual impedance control exceed an actual engineering achievable range in a strong negative impedance scene and parameter setting is complicated and stability and robustness are insufficient in an asymmetric impedance scene. According to the technical scheme of impedance remodeling, the problem is effectively solved by processing symmetric and asymmetric systems in a differentiated mode.

A system includes a first motor, a second motor, and a third motor, each respective motor comprising three phases. The system further includes a voltage source inverter circuit comprising multiple respective inverter legs. Each respective inverter leg coupled to drive at least one phase of at least one of the respective motors, with a first shared inverter leg coupled to drive a third phase of the first motor and drive a first phase of the second motor. A second shared inverter leg is coupled to drive a third phase of the second motor and a first phase of the third motor.

The present invention relates to the technical field of inverter output current filtering. The present invention provides a filtering method for inverter output current that incorporates least squares correction. The method comprises: filtering a three-phase sampled current #imgabs0# output by a two-level voltage source inverter through a fixed-period moving mean filter to obtain a filtered three-phase current #imgabs1#; a three-phase sampled current #imgabs2#; and correcting the filtered three-phase current #imgabs3# using a least squares method under the constraint that the sum of the three-phase currents is zero. The present invention can effectively reduce the impact of hardware circuit and measurement noise on the detected current value.

The utility model provides a three-phase hybrid clamping type three-level inverter with a wide voltage output range, relates to the field of inverters, and specifically relates to a three-phase voltage source inverter. The three-phase voltage source inverter comprises a direct-current voltage source module, a Y-type inversion module, a hybrid clamping module, an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) control module and a three-phase load module. The DC power supply module is used as a DC side power supply of the inverter, the Y-type inversion module under the control of the MOSFET control module can realize inversion output in a wide voltage output range, and through the clamping effect of the hybrid clamping module of the switch bridge part, the whole circuit obtains a higher voltage withstanding level, and the output waveform obtains higher waveform quality. The utility model has the characteristics of wide voltage output range, higher switching frequency, higher withstand voltage level and higher waveform quality, and is very wide in application prospect.

The application discloses a kind of double three-phase permanent magnet synchronous motor adaptive model-free predictive control methods with optimal virtual voltage vector, S1, the mathematical model of double three-phase permanent magnet synchronous motor is established, and the discrete state space prediction model is constructed;S2, establish hyperlocal model ULM, and design extended state observer ESO;The control gain parameters of hyperlocal model and the observer bandwidth of ESO are updated recursively online, and adaptive model-free predictive control AMFPC is formed;S3, construct the virtual voltage vector set for inhibiting harmonic current;The current of motor future time is predicted using updated AMFPC, and the optimal virtual voltage vector is selected from the virtual voltage vector set;The optimized vector is generated through the center symmetrical pulse width modulation mode to generate switching signal, to drive six-phase voltage source inverter, to control double three-phase permanent magnet synchronous motor.The application provides a promising solution for high-performance double three-phase permanent magnet synchronous motor drive system under complex working conditions.

The present invention provides a method and system for dynamic inertia control of a virtual synchronous machine based on artificial intelligence technology, which is applied to the control of a voltage source inverter. The main steps include: data acquisition and preprocessing, and outputting dynamic parameters through a time series neural network for the control links of the virtual synchronous machine respectively; calculating a phase compensation angle by using a convolutional neural network for phase correction of pulse width modulation, and then using a deep reinforcement learning network to output a duty cycle correction amount to adjust the pulse width modulation for collaborative control of the dynamic inertia of the virtual synchronous machine. The present invention obtains dynamically adjusted parameters through data time series processing and neural network application, and can realize adaptive adjustment of core parameters; uses a convolutional neural network to participate in the calculation of modulation signals, effectively compensates for hardware phase delay, and improves the dynamic response accuracy; and then realizes collaborative optimization of inertia control and dynamic response by combining deep reinforcement learning, reduces current overshoot and suppresses harmonics, and improves power quality and system stability.

A method is provided for characterizing junction temperatures of power diodes devices, each of the diode devices being one-to-one connected in antiparallel to each power semiconductor switching devices of a voltage source inverter having processing and measuring capability, the method including: an initialization stage, wherein a heater is thermally coupled with a heatsink and / or with a direct bonded copper element of the voltage source inverter; a temperature setting stage, wherein the temperature of the direct bonded copper element and / or the heatsink is increased up to a maximum operative temperature; a commissioning stage, wherein at each current pulse of a current pulses train sampled data are collected in a sampling period wherein the corresponding power semiconductor switching device connected with at least one of the power semiconductor diode devices is turned-off; an output stage, wherein the processor generates, from the sampled data, processed data for at least one of the power semiconductor diode devices.

The application discloses a high-speed permanent magnet synchronous motor position identification method, samples motor a, b, c three-phase currents, carries out Clarke transformation on the obtained currents to obtain the currents of alpha axis and beta axis on a two-phase static coordinate system, estimates the output voltage of alpha axis and beta axis according to the SVPWM conduction time calculated in the last control period, obtains a position estimation reference quantity by directly processing the current voltage, and uses a phase-locked loop to calculate the angle and speed of the position estimation reference quantity and thereby calculates motor position information, the application uses the output characteristics of a voltage source inverter to obtain a calculation formula not influenced by discretization errors, and improves the position identification precision under a low load frequency ratio.

The invention relates to a self-adaptive prediction control method and system for an LCL type active power filter, and the method comprises the following steps: introducing a self-adaptive weight, dynamically fusing a power supply current frequency domain detection component and a load current time domain detection component, and fusing frequency domain high-precision detection and time domain quick response detection through the self-adaptive weight. The limitation of a single detection mode is overcome, and the compensation precision and the response speed can be improved respectively under the steady-state and transient-state working conditions; the reference current is predicted in advance according to the digital control delay step size, an inverter voltage instruction is calculated in a reverse recursive mode according to the reference current, the inverter voltage instruction is corrected to obtain a final instruction, and the final instruction drives a voltage source inverter to output compensation current; according to the compensation current tracking error and the load power change rate, the self-adaptive weight, the outer ring prediction step length and the self-adaptive virtual damping coefficient are dynamically adjusted, and the overall adaptability of the system to complex working conditions is enhanced.

A stability detection method and system for grid-connected and grid-connected converters based on impedance modeling is proposed. This method determines the impedance matrix of the voltage source inverter based on a small-signal model of the voltage source inverter, and establishes a first impedance ratio, a second impedance ratio, and a third impedance ratio with the equivalent impedance matrix of the power grid. If the first impedance ratio does not satisfy the Nyquist stability criterion, the converter is determined to be in a negatively damped state; if the first impedance ratio satisfies the Nyquist stability criterion, the converter is determined to be in a positively damped or underdamped state. The product of the second and third impedance ratios is used as the oscillation damping coefficient. If the oscillation damping coefficient is less than zero, the converter is determined to be in a negatively damped stable state; if the oscillation damping coefficient is greater than or equal to zero and less than the critical damping coefficient, the converter is determined to be in an underdamped stable state; if the oscillation damping coefficient is greater than or equal to the critical damping coefficient, the converter is determined to be in a positively damped stable state. This method accurately describes the dynamic characteristics of the converter under nonlinear and large disturbance conditions.

The present invention discloses a multi-parameter identification method for an automotive electric drive system that takes into account SiC switching characteristics and motor magnetic saturation characteristics. For a SiC MOSFET voltage source inverter, multiple factors such as dead time, on-off delay, voltage drop, and output capacitance are fully considered, a nonlinear voltage error mathematical model is constructed, and an inverter model parameter offline identification method is designed to reduce the influence of inverter nonlinearity on the motor parameter identification accuracy. At the same time, the present invention considers the influence of magnetic saturation and cross-saturation phenomena of automotive permanent magnet synchronous motors, combines the d-axis current injection method with the step-by-step identification method to solve the lack-rank problem in multi-parameter online identification, and realizes the simultaneous online identification of the stator resistance, AC and DC axis apparent inductance and mutual inductance, and permanent magnet flux electromagnetic parameters, with an identification error not exceeding ±5%.

The invention discloses a grid-connected converter direct-current side midpoint potential balance structure, and the structure comprises a direct-current circuit structure which comprises a direct-current positive electrode, a midpoint potential and a direct-current negative electrode; the multi-winding transformer is provided with a primary side winding and a secondary side winding, and the primary side winding is electrically connected to the direct current circuit structure between the direct current positive electrode and the midpoint potential and the direct current circuit structure between the midpoint potential and the direct current negative electrode through a primary side H-bridge inversion module; and the voltage source type inverter is electrically connected to the secondary side winding, so that an energy interaction channel is formed between the voltage source type inverter and the multi-winding transformer, and when the unbalanced magnetomotive force is generated, the secondary side winding generates a compensation current for the neutral point potential through the energy interaction channel. The primary side of the multi-winding transformer is connected with two capacitors on the direct current side, the secondary side of the multi-winding transformer is connected with the voltage source type inverter, current compensation is carried out on the offset neutral-point potential, the neutral-point potential can be automatically corrected, the development difficulty and delay of a balance algorithm are eliminated, and the adjusting speed and the balance capacity are improved.

The invention relates to a motor control processing unit for a motor control device which comprises a voltage source inverter unit, configured to control the voltage source inverter unit to provide a motor voltage following a pulse-width modulation, PWM, scheme, wherein the motor control processing unit is configured to control the voltage source inverter unit according to a flat PWM scheme, which comprises a flat-bottom or flat-top PWM scheme, at least at some times in order to provide a precise motor control with minimized losses. The invention also relates to a corresponding method.

The invention provides a stability control method and system for a voltage source type inverter of a direct-current micro-grid, and the method comprises the steps: selecting a corresponding double-loop control strategy to control the current according to an inverter architecture when a dq-axis direct current is sent to a control link, i.e., when an additional sensor exists in the inverter architecture, selecting a corresponding double-loop control strategy to control the current; a direct current signal is introduced to the output end of the outer ring PI controller through a proportional element, and current control is carried out; otherwise, the grid-connected current is introduced to the output end of the outer ring PI controller through the corresponding transfer function, and current control is carried out; on the basis of easy implementation, the problem of DC bus voltage oscillation caused by interaction between VSC equivalent DC impedance and line impedance can be effectively avoided, and the stability of the voltage source type inverter is further improved.

The invention relates to the technical field of inverter fault diagnosis. The invention provides a voltage source inverter single-tube open-circuit fault diagnosis method based on a second derivative. The method comprises the steps of calculating an absolute value of a second derivative of each phase in three-phase current output by an inverter when the inverter operates; comparing the calculated absolute value of the second derivative of each phase with a set threshold value, and judging whether the inverter has an open-circuit I-type fault or an open-circuit II-type fault; and when the judgment result is yes, judging whether the inverter has a single-tube open-circuit fault or not by utilizing the symbolic characteristics of the second derivative of each phase in the three-phase current output by the inverter, and positioning a fault power tube. According to the invention, two types of single-tube open-circuit faults can be diagnosed, and the diagnosis reliability is improved.

The application discloses a three-phase two-level voltage source inverter, which comprises: inverter A, B and C three-phase upper and lower working bridge arms V a1 、 b1 、 c1 、 a2 、 b2 、 c2 , corresponding anti-association diodes VD a1 、 b1 、 c1 、 a2 、 b2 、 c2 , upper and lower bridge arm shunt switch devices S1 and S2, three-phase selective switch devices T a1 、 b1 、 c1 、 a2 、 b2 、 c2 in an additional dynamic shunt branch; when the inverter AC side three-phase current has a phase with a maximum positive current, the T a1 、 b1 、 c1 corresponding to the additional dynamic shunt branch are turned on, and the S1 of the additional dynamic shunt branch is shunted in parallel to the phase with the maximum positive current; when a phase with a maximum reverse current exists, the T a2 、 b2 、 c2 corresponding to the additional dynamic shunt branch are turned on, and the S2 of the additional dynamic shunt branch is shunted in parallel to the phase with the maximum reverse current. The application reduces the overcurrent of the inverter working bridge arm switch device caused by AC system disturbance, and improves the operation reliability of the inverter.