590 results about "Matrix converters" patented technology

A variable speed wind turbine is disclosed comprising a turbine rotor that drives a doubly-fed induction generator, a matrix converter which converts variable frequency output into constant frequency output, and a control unit and a protection circuit for the matrix converter. Power is circulated in the system allowing for sensorless detection of rotor position and better output ratios of power from the system.

A matrix converter (38) converts three-phase AC power input from a first motor-generator (MG1) directly to three-phase AC power for driving a second motor-generator (MG2) and outputs the resultant three-phase AC power, without rectifying the three-phase AC power generated by the first motor-generator (MG1) once to DC power as in an example using a conventional three-phase full-wave rectification inverter. In a power supply system for a vehicle (14), the three-phase AC power is transmitted and received between two motor-generators (MG1, MG2) more directly, by means of the matrix converter (38). Therefore, power loss can be reduced, as compared with a conventional example in which the three-phase AC power is once converted to DC power. Thus, a power supply system for a vehicle with improved energy efficiency and a vehicle including the same can be provided.

A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

A DC matrix converter having six forward current conducting power switches and six reverse current conducting power switches has the on time duration of each power switch within each pulse width modulation period controlled by relationships between d, q components of a modulation index determined by the ratio of a voltage command to the instantaneous voltage of the AC mains expressed in stationary d, q coordinates, the selection of which is made based on inequalities between the AC mains voltage components expressed in dq coordinates, and relationships of the AC main voltage components expressed in d, q coordinates. Zero vectors are related to the one AC main having lower line-to-neutral voltage than the other AC mains, using relationships between the instantaneous AC mains voltage in d, q coordinates.

A dual bridge matrix converter has a line-side converter with controllable switches that receives AC power and provides unidirectional power to high and low DC link lines, and a load-side converter which receives the power from the DC link lines and provides AC power to output lines. A clamp circuit is connected across the DC link lines and includes a series connected diode and a capacitor. Negative DC link current will be conducted through the clamp diode to charge the clamp capacitor to avoid voltage spikes on the DC link lines. A controllable switch may be connected in parallel with the clamp diode and is turned on when the voltage across the clamp capacitor is above a threshold that is greater than the normal peak-to-peak AC input voltage. The switch is turned off when the voltage across the clamp capacitor is lower than the threshold voltage.

The invention discloses a matrix converter switch open circuit fault diagnosis method based on prediction control. The method comprises the following steps of under the condition that a matrix converter works normally, establishing relation models between an output voltage and an input voltage, and between an input current and a load current; determining numbers of all the switch combination states of the matrix converter; establishing a state space model and acquiring predicted values of the load current, the input current and the input voltage in a next sampling period; determining an evaluation function; using a finite set model prediction control strategy to select a switch state capable of making an evaluation function value be minimum in all the switch combination states in each sampling period and using the switch state as the switch state of the next sampling period; establishing the state space model and acquiring a change rule of a fault phase load current after a switch open circuit fault is generated; carrying out on-line monitoring on the load current, according to a finite set model, predicting and controlling the selected switch state so as to carry out fault diagnosis, and identifying a fault switch position. By using the method, an open circuit fault can be timely diagnosed.

A matrix converter may be provided with AC switches that comprise bi-directional sets of semiconductor switches that are gated with a common gating link. A low loss diode-bridge based snubber may facilitate introduction of time delay between sequential operations of the bi-directional set of semiconductor switches. The matrix converter may be operated in a three-phase mode with only one gating signals for each AC switch, in contrast to prior-art matrix converters which may require use multiple gating signals for each AC switch.

The present invention provides a LC series resonance high frequency chain matrix-type inverter topology and a resonance modulation method thereof. The topology comprises of a full bridge LC series resonance inverter, a high-frequency transformer T, a matrix converter and a CL-type filter which are connected in order. The modulation method is configured to process the SPWM wave through separation and link semi-excitation modulation logics to obtain driving signals of a transformer pre-stage LC series resonance inverter and a transformer post-stage matrix converter so as to allow the work duty ratio of the transformer pre-stage resonance circuit excitation resonance work state in the resonance half period to be controllable and realize the control of energy side transmission to the output load. The transformer post-stage matrix converter is modulated and decoupled to two common current-type inverters for controlling, a switch tube performs switching during the zero current outputting to realize zero current switching to avoid causing voltage overshoot problems and realize energy bidirectional flow and four-quadrant operation. The power transformation grades are few, the control method is simple, the circuit stability is high, and the like.

An apparatus for producing electrical power from mechanical power, includes a generator with a rotor and a stator for conversion of mechanical power to a polyphase alternating current having more than three phases. The stator has a stator core with a cylindrical stator bore and a plurality of parallel stator slots disposed at a distance from one another, extending axially along a length of the stator core and being open towards the stator bore. A plurality of stator winding bars are disposed in the stator slots so as to form delta-connected windings for producing the polyphase alternating current. A static frequency converter in the form of a matrix converter converts the polyphase alternating current to a desired output alternating current, wherein the stator is a polygonal stator having external winding connections that are bridged, wherein inputs to the matrix converter are connected to end connections of the winding bars. For k stator slots and for a polyphase output with m phases, every k/m-th end connection of the winding bars or evolvent is connected, forming one phase of the polyphase stator output.

The present invention which belongs to the matrix converter control technology is a control method for a matrix converter. An input phase voltage is divided into a main range and a transition range in which new P, M, N conditions and PM, NP, MN transition conditions are defined, some null vector is selected and the condition combination sequence of bidirectional power switches are adjusted in each modulation period to realize the safe, reliable and rapid commutation and the stable operation of the matrix converter. The present invention also provides a device to realize the present method, including a trigger driving circuit, an over-current protecting circuit, a synchronous signal detecting circuit, a voltage range dividing unit, a switch state control unit and a commutation control unit. Based on the two-step commutation strategy of the voltage of the transition range and without an extra measuring device to precisely detect the relative size relation of the input phase voltage, the present invention solves the problem of a short circuit caused by an inaccurate measurement of the input phase voltage during range alteration, and the waveforms of the output voltage and the input current are not affected.

A permanent magnet synchronous motor sliding-mode speed observer driven by a two-stage matrix converter comprises a motor model based on the sliding-mode observer, an S-shaped switch function, an angle calculation module and an angular speed calculation module. Ualpha and Ubeta, obtained through the voltage reconstitution method, of stator voltages in a two-phase static coordinate system of a permanent magnet synchronous motor and the two S-shaped switch function output values (see the specification) serve as the motor model input based on the sliding-mode observer, the stator actual current values including ialpha and ibeta are subtracted from the four motor model output stator current observing values (see the specification) based on the sliding-mode speed observer, the two difference values serve as the S-shaped switch function input, the difference values are processed through the permanent magnet synchronous motor sliding-mode speed observer, then the two counter EMF estimated values in the two-phase static coordinate system are output, the rotor position is obtained through the angle calculation module, and the angular speed is obtained through the angular speed calculation module.

The invention discloses a diode clamped three-level high-voltage matrix converter and a modulation method thereof. The diode clamped three-level high-voltage matrix converter is a novel high-voltage matrix converter formed by connection of two three-phase bi-directional matrix rectifying modules which are in series connection with one diode clamped three-level inverting module. The matrix converter has the advantages of bidirectional flow of energy, sinusoidal input current, controllable power factors, compact structure, output current of good quality, no requirement for a step of direct current energy storage, strong fault-tolerant capability, and the like, and is particularly suitable for medium high-voltage motor drive and a grid-tied wind power generation system.

A matrix converter includes a power converter, a control information generator, a commutation controller, a storage, and an error compensator. The power converter includes bidirectional switches each having a conducting direction controllable by switching elements. The bidirectional switches are disposed between input terminals and output terminals. The input terminals are respectively coupled to phases of an AC power source. The output terminals are respectively coupled to phases of a load. The control information generator generates control information to control the bidirectional switches. The commutation controller controls each of the switching elements based on the control information so as to perform commutation control. The storage stores setting information of at least one of a method of the commutation control and a modulation method of power conversion. The error compensator compensates for an output voltage error based on the setting information.

The invention relates to a pre-charge system and a method for a capacitor of a modular multi-level matrix converter (M<3>C). The pre-charge system and the system achieves pre-charge of the capacitor of the M<3>C and system starting of the M<3>C and have the advantages that pre-charge time of the capacitor is greatly shortened, power loss of a current limiting resistor is reduced and the control is simple. The pre-charge system comprises the M<3>C; an input end of the M<3>C is connected with a series starting current limiting resistor R, a by-pass switch K1, a breaker K2 and an alternating current power supply in sequence; and an output end of the M<3>C is overhung. The pre-charge method comprises the steps that H bridge sub-modules of the M<3>C are divided into two groups, and the capacitor is pre-charged by group.

The invention relates to an LC series resonance high frequency chain matrix type half-bridge inverter topology and a modulation method. The topology comprises a half-bridge LC series resonance inverter, a high-frequency transformer T, a matrix converter and a CL type filter. The modulation method comprises steps that SPWM waves generated in a SPWM signal generation link are processed through series resonance modulation logics to acquire driving signals of a transformer front-level LC series resonance inverter and a transformer back-level matrix converter, a work duty ratio of an excitation resonance work state of a transformer front-level resonance circuit is made to be controllable within a half period, and output load side energy transmission control is realized; the transformer back-level matrix converter is taken as a common current type inverter to control, switching of a switch tube during a transformer zero current output period is carried out to realize a zero current switch, a voltage overshoot problem caused by break of a transformer secondary side leakage current flow path can be avoided, and bidirectional energy flow is realized. The method has advantages of small-quantity power conversion grades, small-quantity switch tubes, simple control and high circuit stability.

The invention discloses a control device and a control method for an AC-DC (Alternating Current-Direct Current) series resonant matrix converter for capacitor charging and mainly aims at solving the problem in the prior art that the control property of a capacitor charging power supply is not high enough to meet the power supply requirement of a high-power microwave system. The control device for the AC-DC (Alternating Current-Direct Current) series resonant matrix converter for capacitor charging comprises a zero-crossing comparator, an On-Off state control unit, a timing sequence generating unit, a control parameter calculation unit, a load voltage acquisition circuit and a trigger driving circuit. The invention further discloses a control method of the control device. With the technical scheme, the control device and the control method, disclosed by the invention, have the advantages that the price/performance ratio is relatively high property, the power supply requirement of the high-power microwave system can be sufficiently met, and the practical value and the popularization value are high.

Systems and methods are provided for delivering current using a matrix converter in a vehicle. An electrical system comprises an AC interface, a first conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the first conversion module, and a control module coupled to the first conversion module. The control module is configured to operate the first conversion module in a bidirectional operating mode to commutate current bidirectionally. When a magnitude of the current through the inductive element is greater than a first threshold value, the control module operates the conversion module in a unidirectional operating mode, wherein current is commutated unidirectionally.

The invention discloses a Z-source two-stage matrix converter with a fault-tolerant topology and a control method thereof, and belongs to the technical field of matrix converter control. A fourth bridge arm used for replacing an open-circuit two-way switch is connected in parallel to the two ends of a rectifier-stage three-phase bridge arm of the Z-source two-stage matrix converter. For a rectifier-stage two-way switching tube open-circuit fault, a rectifier-stage space vector is re-divided to make each sector contain a unique nonzero vector so as to adjust the rectifier-stage fault-tolerant control strategy. When a rectifier-stage expected vector is located in the fault sector, the duty ratio of the shoot-through vector in the fault sector is adjusted, and the inverter-stage fault-tolerant control strategy is adjusted. According to the invention, fault-tolerant operation of the Z-source two-stage matrix converter is realized by the fourth bridge arm and the fault-tolerant control strategies in view of the open-circuit fault of one two-way switching tube of the rectifier stage, and the reliability and security of the matrix converter are improved.