19 results about "Current source inverter" patented technology

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.

The invention relates to a space vector modulation method based on a single-phase parallel current source inverter, and the method comprises the following steps: 1, constructing a single-phase parallel current source inverter circuit, and dividing all current vectors of the single-phase parallel current source inverter according to different amplitudes of output current Iw; 2, analyzing the influence of the small-current vector redundant switching state on the direct current, and constructing a small-current vector switching state selection strategy; 3, analyzing the influence of the zero-current vector redundant switching state on the direct current, and constructing a zero-current vector switching state selection strategy; and step 4, in each sampling period, synthesizing a reference current vector Iref by two static current vectors which are closest to each other according to an ampere-second balance principle, collecting a power grid voltage us and direct currents i1-i4 at the same time, and selecting a redundant switch state according to the strategies in the step 2 and the step 3 to realize the current balance of the direct current bridge arm. According to the invention, the waveform quality of the grid-connected current can be improved.

The invention discloses a multi-level current source inverter and a control method thereof, and relates to the field of electric energy conversion control, the multi-level current source inverter is composed of an MCSI module, a direct current side inductor, a coupling capacitor, a ripple filter and a control module, and the three-phase voltage and the load current of a power grid are measured; calculating a reference phase under a synchronous rotating coordinate system by using a three-phase digital phase-locked loop, and further decomposing the reference phase into a current mean value and an alternating current component; a current error is obtained by establishing an additional control loop, and a DC component is separated from the current error by using a PI controller; generating a reference current under the synchronous rotating coordinate system, converting the reference current back to the three-phase coordinate system, and generating an actual gate driving signal of the MCSI module; based on an actual gate pole driving signal, the actual gate pole driving signal serves as a reference of phase shift carrier SPWM, and zero-state selection and inductive current balance are optimized in cooperation with a logic state machine. The method is used for power quality management of the power distribution network, harmonic waves and reactive power can be suppressed, and switching loss is reduced.

The application discloses a current source inverter high-speed permanent magnet synchronous motor control method and system based on LADRC, and the system part comprises a position estimation module, a rotating speed regulator, a current sensor, a voltage sensor, a coordinate transformation matrix, a current regulator, a current generation module and a space vector pulse width modulation module; the control method part calculates an inverter current reference value through design of a second-order LADRC current regulator, realizes d-q axis decoupling in the regulator, improves the dynamic performance of the current source inverter, effectively reduces current harmonics, and improves the anti-interference ability and robustness of the system. The application can not only solve the system instability problem caused by high control order and serious coupling of the motor under high-speed working conditions, improve the robustness and dynamic performance of the system, but also solve the problems of high cost and low reliability of the traditional position sensor under high-speed operation, reduce the hardware cost of the system, and speed up the response speed. The application relates to motor control technology.

There is provided a current source inverter (CSI) comprising at least one Gallium Nitride (GaN) transistor including a gate, wherein a predetermined voltage value is applied to the gate of the GaN transistor for at least a portion of time, in order to provide an extended reverse voltage blocking capability for the GaN transistor.

The application discloses a kind of three-phase full-bridge current source type inverter, belong to current source type inverter technical field, comprising: constant current source, inductance, multiple power switch tubes, capacitor and three-phase motor;Wherein, the constant current source is connected in series with the inductance;Multiple power switch tubes are connected to output alternating current to drive motor;Each the power switch tube is used to ensure the unidirectional flow of bridge arm current;Each phase winding in the three-phase motor is provided with two power bridge arms, and the first power bridge arm and the second power bridge arm of each phase winding each include two power switch tubes;The bridge arm midpoint of two power bridge arms is connected with the two ends of the phase winding;Each phase winding end is connected with one capacitor in parallel.The application is improved on the basis of conventional three-phase bridge type current source inverter, each phase winding is provided with two power bridge arms, and each power bridge arm is provided with two power switch tubes, which can significantly improve current utilization and fault tolerance.

The application is a current source type inverter topology structure with energy feedback loop and a control method. The application relates to the technical field of power electronics and motor control, and a switching tube and a diode are used to provide stable DC side current, so that the controllable operation of the motor is ensured, and on this basis, only a switching tube and a resistor are used to realize the discharge of motor feedback energy, so that the safety and reliability of the motor four-quadrant operation are ensured under the condition of the simplest topology and low cost. Compared with the existing current source inverter system with DCDC front stage, only two switching tubes and a diode are used in the realization of the function, the system is simplified, the reliability of the system is increased, and the cost is reduced.

The application discloses a five-phase half-bridge current source type inverter low-harmonic vector sequence generation method, belongs to the technical field of motor control, and aims at solving the problem of harmonic increase caused by the sudden change of phase voltage amplitude due to sector switching in the adjacent four-vector modulation strategy of the traditional five-phase half-bridge current source type inverter. The method comprises the following steps: S1, obtaining motor operation state information and determining a reference current vector in a stationary coordinate system; S2, judging a sector where the reference current vector is located; S3, selecting a basic non-zero vector corresponding to the sector and a zero vector for supplementing a switching period; S4, calculating the action time of each non-zero basic vector in the sector; S5, calculating the action time of the zero vector; S6, according to the parity of the sector number, dividing the sector into an odd sector and an even sector, and adopting different vector action sequences for the odd sector and the even sector; and S7, performing pulse width modulation according to the vector action sequence generated in step S6 to drive the five-phase motor to operate.

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.

This application provides a method and apparatus for adjusting the firing angle of a turn-off current source converter. The maximum firing angle of the turn-off current source converter can be calculated based on the DC voltage protection value and the sampled values ​​of the three-phase AC phase voltages. An upper limit value for the firing angle of the turn-off current source converter is calculated based on the maximum firing angle. The firing angle of the turn-off current source converter is then adjusted based on this upper limit value. In the event of a three-phase AC fault at the receiving-end converter station, adjusting the firing angle can reduce the reactive power absorbed by the turn-off current source converter. Combined with other reactive power compensation devices, reactive power can be injected into the AC system. After the three-phase AC fault is cleared, it supports the restoration of AC voltage in the AC power grid, thus improving the turn-off current source converter's ability to support transient reactive power in the AC power grid.

The invention relates to the technical field of motor control, in particular to a permanent magnet motor model predictive current control method based on a current source type inverter. Comprising the following steps: collecting the operation state quantity of a motor system, and carrying out Park conversion to obtain an operation measured value; according to the operation measured value, an alternating current side parallel filter capacitor branch model and a permanent magnet synchronous motor mathematical model are established, a unified discrete prediction model is constructed, and an inverter output current vector and a capacitor current in the next period are obtained through calculation; constructing a capacitance current steady-state reference component and a capacitance current deviation component; and constructing a cost function, selecting an output current vector with the minimum cost function as an optimal control vector of the current control period, and generating an inverter switch driving signal to drive CSI to operate. According to the method, stator current tracking and alternating current side oscillation suppression are considered at the same time under a unified prediction model framework, and compared with a traditional strategy, the dynamic response speed and the steady-state waveform quality can be better considered.

A motor control system includes: a d-q target module configured to determine a first target d-axis current and a first target q-axis current based on a target torque of an electric motor; an offset module configured to determine a d-axis current offset and a q-axis current offset based on capacitor currents through capacitors connected across each phase of the electric motor; an adder module configured to determine a second target d-axis current based on the sum of the first target d-axis current and the d-axis current offset, and to determine a second target q-axis current based on the sum of the first target q-axis current and the q-axis current offset; and a driver module configured to switch a current source inverter (CSI) module based on the second target d-axis current and the second target q-axis current, the CSI module being configured to apply power to a phase of the electric motor.

A prediction method for a crosstalk voltage spike in a half bridge of current-source inverter with silicon carbide devices includes calculation of the crosstalk voltage spike in the circuit of current-source type double-pulse test and analysis of the effect of each parameter on the magnitude of the crosstalk voltage spike. The prediction method analyzes the horizontal conduction crosstalk mechanism between the gate-source junction of the MOSFET caused by the high-frequency switching action of the silicon carbide (SiC) MOSFET and the SiC Schottky diode connected in series, and derives the prediction model. Based on the equivalent circuit of the current-source-type double-pulse test and the crosstalk-induced mechanism, the extreme value of crosstalk voltage spike is accurately predicted, which is helpful to analyze the effects of the drive circuit and the parameters of the power circuit on the crosstalk voltage spike through the prediction model.

This invention discloses a high-fault-tolerant current source inverter topology for driving open windings, belonging to the field of motor control. It addresses the problems of insufficient short-circuit fault tolerance and difficulty in suppressing open-circuit voltage spikes in traditional current source inverter topologies. The invention includes a DC current source, a bus inductor, and an inverter unit. The DC current source and bus inductor are connected in series to provide a stable and controllable DC current to the inverter unit. The inverter unit contains two sets of parallel branches composed of switching devices and diodes, forming n output ports to supply power to each phase winding. It can maintain a single continuous bus current path even after a short circuit in a switching device, further realizing short-circuit fault-tolerant control. The switching devices and diodes in the two sets of parallel branches are arranged in a staggered manner. By connecting n+1 flying capacitors between the upper and lower branches of the inverter unit, during the transient process after an open circuit in a switching device, the flying capacitors can form a continuous current path with two adjacent diodes, preventing overvoltage problems.

The application discloses a high-speed motor current source inverter decoupling control method and system. The application firstly realizes current loop complex vector decoupling and voltage loop feedforward decoupling control on the basis of a high-speed motor speed-current-voltage three-closed-loop control system, and secondly, in order to avoid the decoupling algorithm from failing in a high-speed working condition and causing system instability, active damping based on stator current feedback is proposed to increase the system phase margin and suppress resonance peaks. The application solves the system instability problem caused by decoupling failure of the motor in a high-speed working condition, and realizes high-speed motor full-speed-domain decoupling control.

This invention relates to a two-degree-of-freedom active disturbance rejection (ADNR) control method for a dual three-phase motor driven by a nine-switch current source, belonging to the field of permanent magnet motor control technology. The invention addresses the coupling problem between tracking and disturbance rejection performance in traditional ADNR control for dual three-phase permanent magnet synchronous motors based on current source inverters. The invention includes: establishing a mathematical model of the dq-axis current loop of a nine-switch current source inverter in a synchronous rotating coordinate system, incorporating both periodic and aperiodic disturbances; designing an improved extended state observer, removing the error correction term for the current tracking signal and its differential signal update law in the traditional extended state observer, and designing the disturbance update law as a proportional-integral-repetitive control structure; constructing a two-degree-of-freedom ADNR controller based on the control characteristics of the current source inverter, and independently adjusting the reference tracking performance and disturbance rejection performance based on the output of the improved extended state observer, achieving complete decoupling between the two.

A current source inverter includes a first phase leg comprising a plurality of switching devices, a second phase leg comprising a plurality of switching devices, and a third phase leg comprising a plurality of switching devices. The current source inverter further includes a zero state phase leg comprising at least one switching device, wherein the zero state phase leg is configured to transition from an open state to prevent current flow to a closed state to allow current flow between a positive terminal and a negative terminal during a dead time.

The embodiment of the invention provides a network construction type current source inverter circuit, a control method and related equipment, and belongs to the technical field of power grid connection. According to the scheme, the network-forming type current source inverter circuit comprises a DSP (Digital Signal Processor) chip and a current source inverter integrated with an integrated gate commutated thyristor, the DSP chip is used for generating a control signal for driving the current source inverter; the current source inverter is integrated with an integrated gate commutation thyristor, the integrated gate commutation thyristor is connected with a DSP chip, and the DSP chip controls the on-off of the current source inverter through the integrated gate commutation thyristor. According to the embodiment of the invention, the integrated gate commutated thyristor is used as a switching tube of the PWM control current source type grid-forming inverter, and the integrated gate commutated thyristor has the characteristics of high rated voltage and large rated current, so that the number of power devices can be reduced compared with other technologies.

The application relates to the technical field of motor control, in particular to a permanent magnet motor model predictive current control method based on a current source type inverter. The method comprises the following steps: collecting the operation state quantity of a motor system, and performing Park transformation to obtain an operation measured value; according to the operation measured value, an alternating current side parallel filter capacitor branch model and a permanent magnet synchronous motor mathematical model are established, a unified discrete prediction model is constructed, and the inverter output current vector and the capacitor current of the next period are calculated; a capacitor current steady-state reference component and a capacitor current deviation component are constructed; a cost function is constructed, the output current vector with the minimum cost function is selected as the optimal control vector of the current control period, and an inverter switching driving signal is generated to drive the CSI operation. According to the application, the stator current tracking and alternating current side oscillation suppression are simultaneously considered under the unified prediction model framework, and compared with the traditional strategy, the dynamic response speed and the steady-state waveform quality can be better considered.