514 results about "Three phase rectifier" patented technology

The embodiment of the invention discloses a total power aging test circuit for a current transformer or a frequency transformer. The total power aging test circuit comprises a filter reactor, a boosting transformer and a direct-current power supply, wherein the direct-current power supply is communicated with two ends of a bus capacitor; the input end of the boosting transformer is communicated with the output end of a three-phase inverter through the filter reactor, and the output end of the boosting transformer is communicated with the input end of the three-phase inverter. The total power aging test circuit also comprises an aging test module arranged in a controller and an aging test triggering unit arranged on human interface device. The aging test triggering unit is used for controlling the running state of the aging test module, and the aging test module is used for controlling the current transformer or the frequency transformer for an aging test. The total power aging test circuit can effectively reduce the energy consumption in the aging test process, simplifies the structure of a test system, and reduces the maintenance cost of the system.

An AC/DC converter system comprises an input circuit for connection to a three phase AC source. An isolation transformer comprises a set of primary windings and first and second sets of secondary windings magnetically coupled to the set of primary windings. The first and second sets of secondary windings are phase shifted by select amounts from the set of primary windings. The set of primary windings is connected to the input circuit. An AC/DC converter comprises first, second and third three phase rectifiers, the first three phase rectifier being powered by the first set of secondary windings, the second three phase rectifier being powered by the second set of secondary windings, and the third three phase rectifier being powered by the input circuit. An impedance matching inductor is electrically connected between the input circuit and the third three phase rectifier. An output circuit is connected between the AC/DC converter and a DC load.

The invention discloses a winding open-circuit type permanent magnet motor vehicle starting and generating system and a control method. The system comprises a winding open-circuit type permanent magnet motor, a three-phase rectifier bridge, a three-phase bridge converter, a changeover switch, a filter capacitor, a storage battery, a controller, a voltage and current test circuit, a drive circuit and a load. In the method, one side of the winding head of the winding open-circuit type permanent magnet motor forms a rectifying side to supply power to the load through the three-phase rectifier bridge and the filter capacitor, and the other side is connected with the three-phase bridge converter and the storage battery to form an inversion control side. The changeover between the starting operation state and the generating operation state is realized through the changeover switch, starting control adopts single-current closed loop vector control, generating operation adopts rectifying side DC voltage and motor-phase current double closed loop control, and stable output voltage and generator high-efficiency operation control are realized. The winding open-circuit type permanent magnet motor starting and generating system can effectively meet the requirements of wide revolution operating range, high power density and high efficiency of a vehicle starting generator.

The invention relates to a high-frequency high-voltage switching power supply for electric precipitation. Three-phase alternating-current is input and converted into direct current by a three-phase rectifier filter circuit and then the direct current passes through a high-frequency inverter circuit; a series-parallel connection resonant soft switching circuit is connected between two inverter bridge arms in the high-frequency inverter circuit; the output of the series-parallel connection resonant soft switching circuit is boosted by a high-frequency pulse transformer, the boosted output passes through a high voltage silicon rectifier stack to form high-voltage direct current and the high-voltage direct current is input into an electric precipitator; a DSP controller outputs a control signal to the high-frequency inverter circuit; the input side of the electric precipitator is connected with a voltage and current detection circuit; the detection circuit detects voltage and current and inputs a signal into the DSP controller; the high-frequency inverter circuit is adjusted by the DSP controller; and the DSP controller is connected with an upper computer through a CAN interface so asto realize optimal control. The switching power supply is used for electric precipitation equipment and has the advantages of small volume, light weight, light harmonic pollution, high power factor, high conversion efficiency, and capability of generating waveforms meeting various working condition requirements of the electric precipitation equipment so as to realize energy conservation and emission reduction.

The invention discloses a three-phase rectifier rapid model predictive control method. According to the technical scheme, the method is characterized by including the steps that an output voltage reference value needed by a next moment is acquired according to a three-phase voltage rectifier model and a current reference value, equivalent transformation is conducted on a value function in model prediction control to acquire a value function expression based on output voltage, and lastly an optimal output voltage vector is chosen through a vector zonal method. Specific to the control of a three-phase voltage rectifier, the model predictive control method can effectively simplify the steps of traditional model predictive control. Therefore, the control algorithm structure is simple, calculation amount is small, calculation time is remarkably shortened, response speed of a control system is guaranteed, stable operation of the control system is guaranteed, and conditions are provided for expanding other auxiliary control algorithms.

The invention discloses a model predication control method of a three-phase PWM (pulse width modulation) rectifier under unbalanced voltage. The technical scheme mainly includes that the model predication control method of three-phase PWM rectifier under unbalanced voltage includes: negating input active power and input reactive power which are obtained by computation, enabling negated values to pass through proportional resonant controllers, obtaining second harmonic compensation voltages under a two-phase rotating coordinate system by means of compensating voltage computation, then obtaining second harmonic compensation voltages under a two-phase static coordinate system by means of reverse Park transformation, compensating the second harmonic compensation voltages under the two-phase static coordinate system into output voltage subjected to traditional model predication control, enabling voltage vectors with the minimum absolute values, which are differences of current given values and current predication values, to serve as optimal voltage vectors by value function selection, and using the optimal voltage vectors as switching signals for controlling power devices. The model predication control method of the three-phase PWM rectifier under unbalanced voltage is capable of effectively inhibiting second harmonic fluctuation of input power of the rectifier under the condition of unbalanced power grid voltage, and is simple in control structure, short in system delay and capable of simultaneously eliminating secondary pulses of input active power and input reactive power of the system.

The invention provides a correction policy of current zero-crossing distortion applicable to all one-way three-phase rectifiers (including three-phase VIENNA rectifiers, three-phase bridgeless rectifiers and all star-connection cascaded three-phase rectifier topologies) based on single-period control. The policy specifically includes following steps: firstly, determining related parameters of a system, then calculating a current distortion initial point, a distortion time and a boundary condition, and finally calculating a parameter introduced compensation amount based on the above parameters.According to the policy, based on the characteristic of single-period direct current control, crossed injection is performed on the feedback of current phase-shift control signals, and superpositionis performed with an original phase-shift feedback amount so that zero-crossing distortion generated by current phase shift of the energy one-way flow three-phase rectifier is corrected without increasing the complexity of the system. According to the policy, the realization is simple, the reliability is high, an effective correction method is provided for the current zero-crossing distortion problem occurring in a single-period control process, and the application range of single-period control is extended.

The invention discloses a permanent magnet generator system with variable leakage reactance and large rotating speed range output, solving the problems of complex control and low reliability in the traditional permanent magnet generator system. The number of rotor poles of a three-phase permanent magnet synchronizing generator in the system is 10n; a phase difference between two sets of three-phase windings of a stator is a 30-DEG electric angle; the number of slots of a stator iron core is 12n, the two sets of three-phase windings are concentrated windings, 6n coils constituting each set of three-phase winding are uniformly distributed and wound on an armature core tooth along the circumference, one set of winding with more turns is embedded in the bottom layer of a slot, the other set of winding with less turns is embedded in the upper layer of the slot, a leakage resistance regulating sheet is arranged between the upper winding and the lower winding; and the output end of each set of three-phase winding is connected with the alternating-current input end of one three-phase rectifier, and direct-current output ends of the two three-phase rectifiers are connected in parallel or in series and then connected to a common direct-current bus. The invention is suitable for wind power generation systems.

The invention discloses a three-phase inverter topology structure with adjustable DC bus voltage and a method of adopting the structure to realize dynamic DC bus voltage adjustment, which belong to the field of high-speed motor spindle driving control, and solve the problem that the existing inverter topology structure results in huge torque ripple in a controlled high-speed motor, applied square wave voltage during the control process generates current harmonics rich in a harmonic spectrum, and thus, loss in the motor is increased abruptly. The topology structure comprises a three-phase rectifier bridge, a DC bus supporting capacitor, a DC bus input voltage detection module, a Buck-Boost voltage adjusting circuit, a DC bus output voltage stabilizing capacitor, a DC bus output voltage detection module, a three-phase half-bridge inverter circuit, a three-phase current detection module and a driving control circuit. The dynamic bus voltage adjustment method is realized by adopting a DC bus voltage online dynamic adjustment strategy and a sensorless control strategy. The structure and the method are mainly used to dynamically adjust the DC bus voltage according to a motor operation state.

The invention provides a large-power steady transmitting device with a continuously adjustable voltage width range. The device is characterized in that current is respectively input into a three-phase rectifier, a high-frequency inverter, a high-frequency transformer and the like by multiple generator sets, the output end of the high-frequency transformer performs power synthesis and then outputs voltage commutation, and a constant-current output device capable of adjusting output voltages within a large range can be realized through a control inverter circuit. According to the invention, the capacity of a single generator can be effectively reduced, the output voltage can be adjusted within a wide range, the control strategy is simple, and high-current, high-precision and steady load can be realized.

The invention provides a wind power generation intelligent single-phase grid-connection controller. A signal output end of a corresponding three-phase rectifier unit is connected with a signal input end terminal of a direct current input switch, a direct current signal output end of the direct current input switch is connected with a direct current signal input end of a direct current step-up circuit, and the direct current signal output end of the direct current step-up circuit is connected with a direct current signal input end of an inverter circuit; a signal output end of the inverter circuit is connected with the signal input end of a filter unit, a filtering signal output end of the filter unit is connected with a filtering signal input end of a grid-connection switch, and a signal output end of the grid-connection switch is connected with a signal input end of an electric energy bidirectional metering unit; the measuring signal input end of the electric energy bidirectional measuring unit is connected with a measuring signal input/output end of a main control unit, a driving signal output end of the main control unit is connected with a driving signal input end of a drive circuit, and a sampling signal output end of a sampling circuit is connected with a sampling signal input end of the main control unit.

A motor drive control device includes a three-phase rectifier; a boosting circuit including a reactor, a switching element, and a backflow preventing element and boosts a direct-current bus voltage supplied from the three-phase rectifier; a smoothing capacitor; an inverter circuit; a boosting control unit; an inverter control unit; and a circuit protecting unit suppresses a ripple current flowing through the smoothing capacitor. In the circuit protecting unit, a correlation of an on-duty ratio of the switching element included in the boosting circuit, the output power of the inverter circuit, and an estimated ripple current are set. On the basis of the on-duty ratio of the switching element, output power of the inverter circuit, and the correlation, the circuit protecting unit determines an estimated ripple current flowing through the smoothing capacitor. When the estimated ripple current exceeds a preset threshold, the circuit protecting unit suppresses the ripple current.

The invention discloses a predictive control method of a fixed-frequency module of a three-phase PWM (pulse-width modulation) rectifier. The predictive control method is characterized by comprising the following steps of: selecting two voltage vectors and a zero vector adjacent to a power grid voltage position angle to serve as action vectors; taking the acquired power grid voltage and input current values under a two-phase rotary coordinate system and voltage values under the two-phase rotary coordinate system corresponding to the selected two voltage vectors and zero vector to serve as input of a current predictive model to as to acquire a change rate of current on d and q axes; and calculating input of the module by adopting the input current value, the reference value of current on the d and q axes and the change rate of current on the d and q axes as vector duration; inputting the action time of each vector into a modulator; and taking the switch position signal as a switch signal for controlling a power device. According to the predictive control method, the system current ripple and current distortion can be effectively reduced, and the operation performance of the model predictive control system can be reinforced.

A soft start control system for a high-speed brushless DC motor mainly comprises a digital controller, a controllable three-phase rectifier bridge, a DC chopper, a three-phase inverter bridge, a current sensor, the high-speed brushless DC motor and other parts. In order to solve the problem that the start current of the high-speed brushless DC motor is large, the controllable three-phase rectifier bridge and the DC chopper are adopted to carry out two-stage voltage modulation so as to control the DC bus voltage of the three-phase inverter bridge; and the digital controller is adopted to regulate the duty ratio of five-path PWM (Pulse-Width Modulation) drive signals and six-path phase commutation signals according to three-phase inverter bridge DC bus current feedback signals and motor rotation speed feedback signals and control the three-phase inverter bridge DC bus voltage and the phase commutation frequency so as to realize the voltage-reduction variable-frequency soft start of the brushless DC motor. The soft start control system provided by the invention effectively solves the soft start problem of the high-speed brushless DC motor, and has a significant application value for the research of the soft start control of the high-speed brushless DC motor.

The invention relates to a high power factor cascade stage speed regulating device of phase-shifting chopped waves. A rotor side of an inner feedback motor is connected with two three-phase rectifiers through a Y/Y/Delta transformer to form a 12-pulse rectifier for reducing the content of harmonic wave at the rotor side and improving the power factor of the rotor side; a direct current side of the rectifier is connected with a phase-shifting chopper to reduce direct current pulsation and improve the reliability and stability of the chopper; the back ends of two choppers are connected with a common bus; the two choppers feedback the inversed current to the power grid through a PWM rectifier, which can not only reduce the content of harmonic wave and improve the power factor, but also prevent inversion and subversion effectively. The invention can not only reduce the harmonic current at the rotor side, but also reduce the harmonic current at the inversed side, thus reducing the content of harmonic wave of the whole speed regulating device, and greatly improving the power factor of the cascade stage speed regulating device.

The invention discloses an intelligent medium-frequency high-voltage double-output direct current power supply for electric dust removal. The direct current power supply comprises a three-phase air switch with a tripper, a three-phase rectifier, a filter, a single-phase medium-frequency inverter, an air switch, a medium-frequency step-up transformer, a medium-frequency double half-wave rectifier,a first high-voltage direct current output sampling circuit, a second high-voltage direct current output sampling circuit, an isolating driver and a digital signal processing (DSP) controller, wherein the medium-frequency double half-wave rectifier of the direct current power supply is used for outputting two paths of direct current high voltage; the two paths of direct current high voltage are fed back to the DSP controller through two paths of sampling circuits; and a control signal is output to the single-phase medium-frequency inverter by the DSP controller to adjust frequency and amplitude. The direct current power supply has the characteristics of high output voltage, balanced power grid input and capability of greatly reducing pollution to a power grid and improving the utilizationefficiency of power; and a medium-frequency high-voltage silicon rectifier double-output transformer which is matched with the direct current power supply has the characteristics of small volume, light weight, low manufacturing cost and high efficiency. The direct current power supply has a wide application range and can be applied to construction of a new dust removal electric field, synergetic reconstruction of an old electric field and the like.

The invention discloses a self-correcting prediction control method of a model of a three-phase voltage type PWM (Pulse-Width Modulation) rectifier. According to the technical scheme point provided by the invention, when model parameters of a controlled member are mismatched, actual model parameters are observed and a prediction model is modified in real time by the self-correcting prediction control method of the model of the three-phase voltage type PWM rectifier, an optimal voltage vector is then obtained, and a switch position signal corresponding to the obtained optimal voltage vector is taken as a switch signal for controlling a power device. According to the self-correcting method of the model provided by the invention, on the premise that a hardware structure is not changed, the influence of mismatched model parameters on a control system is eliminated, the robustness of a prediction control system of the model in enhanced, and the stable operation of the three-phase voltage type PWM rectifier under a condition that a large error exists in the prediction model is realized by adding an inductance observing algorithm.

The invention relates to an electromagnetic transmitter. The electromagnetic transmitter comprises an electric generator set, a three-phase rectifier bridge, filter capacitors, a first level inverter bridge, a resonant inductor, an insulation value capacitor, a high-frequency transformer, a high-frequency rectifier bridge, a LC filter circuit and a second level inverter bridge. The electric generator set, the three-phase rectifier bridge, the filter capacitors, the first level inverter bridge, the high-frequency transformer, the high-frequency rectifier bridge, the LC filter circuit and the second level inverter bridge and an output port are successively connected. The resonant inductor and the insulation value capacitor are connected in series to a line between the first level inverter bridge and a primary side of the high-frequency transformer. The filter capacitors are connected in parallel to each power device of the first level inverter bridge. The filter capacitors, the resonant inductor and the insulation value capacitor form a resonance loop. By using the electromagnetic transmitter, a soft switch technology is used in the first level inverter bridge so that the voltage of the power devices of the first level inverter bridge during an on or off process is zero; zero voltage switch of the power devices is realized.

A capacitor-input type three-phase rectification circuit comprises a three-phase AC power supply (1), a diode rectifier circuit (4), and a low-frequency filter connected between the three-phase AC power supply (1) and the diode rectification circuitry (4), the low frequency filter consisting of AC reactors (2u)(2v)(2w) and Δ-connection or Y-connection capacitors (8u)(8v)(8w), so that higher harmonic currents are reduced to be equal to or less than standard values, and that lowering in input power factor and lowering in DC voltage are prevented from occurrence.

The invention provides a high-capacity reversible charging and discharging device which is characterized by comprising a reversible electric power storage and charge-discharge unit, a data display control unit, an insulation detection unit, a storage battery, a storage battery detection unit and an upper computer, wherein the reversible electric power storage and charge-discharge unit sequentially comprises a transformer, a space vector pulse width modulation (SVPWM) reversible three-phase rectifier inverter bridge, a digital signal processor (DSP) data controller and a two-way DC (direct current)/ DC conversion module used for converting charging and discharging modes; the reversible electric power storage and charge-discharge unit is led out from a high-voltage system bus; an output end of the reversible electric power storage and charge-discharge unit is connected with the storage battery; the data display control unit is respectively connected with the reversible electric power storage and charge-discharge unit, the insulation detection unit and the storage battery detection unit; the storage battery detection unit is connected with the storage battery by data; and the insulation detection unit is connected with an output end of the reversible electric power storage and charge-discharge unit. The reversible electric power storage and charge-discharge unit is added into the device, so that the device integrates reversible charging and discharging; therefore, the device can be used for rectifying charging and discharge inversion to realize grid-connected operation with the main power grid.

In one aspect of the invention, a three-phase rectifier circuit having three input terminals and two output terminals includes a three-phase diode bridge, three switching circuits, and a voltage source. The three-phase diode bridge has three pairs of first diodes electrically parallel-connected to the two output terminals. Each pair of first diodes has two first diodes series-connected defining a first node therebetween, and electrically connected to a corresponding input terminal at the first node. Each switching circuit has a first terminal, a second terminal and a plurality of switches electrically series-connected between the first and second terminals. The first and second terminals are respectively electrically connected to a second node and a third node, respectively between the first node and the two first diodes of the corresponding pair of first diodes. The voltage source is electrically parallel-connected between the two output terminals and electrically connected to each switching circuit.

The invention relates to a novel transformer test power supply which comprises a high-voltage frequency-conversion test power supply, an intermediate boosting transformer and a reactive compensation device, wherein the high-voltage frequency-conversion test power supply is connected with the intermediate boosting transformer which is connected with a tested transformer; the input end of the tested transformer is connected with the reactive compensation device; the high-voltage frequency-conversion test power supply is of a structure that power units are serially connected with a plurality of electric levels; and a basic structure of the power units is an alternating current-direct current-alternating current three-phase rectifier and single-phase inverter circuit; and three secondary side windings of a phase-shifting transformer form a group which respectively supplies power to the three power units of the same level, and a plurality of power units of each phase are connected in series together to form three-phase high-voltage power output in star-shaped connection. The novel transformer test power supply has the advantages: the high-voltage frequency-conversion test power supply is directly used as a transformer test power supply and outputs various frequencies of voltage required by a test; and the test power supply can output continuous and adjustable voltage and three-phase alternating current with the frequency adjusting range of 0-200Hz and provides a wide voltage and frequency adjusting range for the transformer test.