215 results about "H bridge inverter" patented technology

A power converter includes an active front end (AFE) that is coupled by a dc link stage to a plurality of H-bridge inverters. One or more multi-phase electro-magnetic energy conversion devices, such as transformers or electric machines, with open windings that are connected to only the AFE or only the H-bridge inverters or to both the AFE and H-bridge inverters, provide a regenerative or partial regenerative power converter.

The invention discloses a cascaded photovoltaic grid-connected inverter and a control method. The cascaded photovoltaic grid-connected inverter has the advantages of high voltage level, high power level, high power quality and the like, and can realize direct high voltage grid connection without any transformer to save cost and an occupied area. The inverter comprises a photovoltaic array and a plurality of cascaded unit bodies. The photovoltaic array comprises a plurality of photovoltaic units of which each is connected with the input side of a corresponding unit body. Each unit body is a single-stage single-phase photovoltaic grid-connected inverter which comprises a DC bus capacitor and an H bridge inverter circuit, wherein the DC bus capacitor is connected in parallel to the input endof the single-stage single-phase photovoltaic grid-connected inverter; and the H bridge inverter circuit is connected in parallel with the DC bus capacitor.

The invention relates to an active power quality adjuster, consisting of a fundamental wave compensation part and a harmonic wave compensation part, and the two parts compensate fundamental current and harmonic current respectively. An H-bridge cascade multilevel inverter and a fundamental wave connection inductance are connected in series at the fundamental wave compensation part, so that reactive compensation and unbalanced load compensation can be dynamically carried out; the H-bridge cascade multilevel inverter and a unituning passive filter are connected in series to form the harmonic wave compensation part which is connected across the two ends of the fundamental wave connection inductance. Therefore, the power quality adjuster can lower switching frequency and loss of the H-bridge cascade multilevel inverter at the fundamental wave compensation part greatly on one hand, and only a fraction of fundamental current passes the harmonic wave compensation part and the whole part only undertakes fundamental voltage of the fundamental wave connection inductance without undertaking fundamental voltage on the other hand, thereby effectively reducing the capacity of the H-bridge inverter and the withstand voltage at the harmonic wave compensation part.

The invention relates to a device for the high-speed off of an energy-feedback constant-voltage clamp. The device comprises a constant voltage source circuit, a clamp circuit and an H bridge inverter circuit, wherein the constant voltage source circuit provides stable voltage during the falling edge of emission current; the clamp circuit provides a current pathway for a transmitting antenna during the falling edge of the emission current, and energy in the transmitting antenna is released to the constant voltage source circuit, so that the voltage on the transmitting antenna reaches a voltage value of a constant voltage source to realize the voltage clamp purpose. The invention further provides a method for the high-speed off of a transient electromagnetic transmitter and the energy-feedback constant-voltage clamp. The device provided by the invention can realize high-speed and linear off during the falling edge of the current, is small in tail oscillation, effectively restrains current overshoot, feeds back the energy stored in the transmitting antenna during the falling edge to the constant-voltage source and releases during the rising edge of a next emission current pulse, so that the current rapidly rises, the energy loss is reduced, moreover, the working efficiency of the transmitter is improved.

The invention provides a three-phase H-bridge driving system for an open type winding induction motor and belongs to the field of motor control. The three-phase H-bridge driving system aims to solve the problem that a double-inverter modulation algorithm adopted for an existing open type winding induction motor is complex. According to the scheme, a DC filter capacitor, an A-phase H-bridge inverter, a B-phase H-bridge inverter and a C-phase H-bridge inverter are sequentially connected to a DC bus output from a rectifier in parallel; an A-phase winding of the open type winding induction motor is connected between two AC output ends of the A-phase H-bridge inverter in parallel, a B-phase winding of the open type winding induction motor is connected between two AC output ends of the B-phase H-bridge inverter in parallel, and a C-phase winding of the open type winding induction motor is connected between two AC output ends of the C-phase H-bridge inverter in parallel; a V/F controller receives a rotational speed instruction nr and outputs three-phase symmetric sinusoidal modulated waves uar, ubr and ucr to a bipolar SPWM modulator; the bipolar SPWM modulator compares the three-phase symmetric sinusoidal modulated waves uar, ubr and ucr with triangular carrier signals to generate six-channel switching signals, and then outputs 12-channel driving signals to the A-phase H-bridge inverter, the B-phase H-bridge inverter and the C-phase H-bridge inverter through an isolation and driving unit.

A clamp five level frequency conversion driving device with internal and external double-set of rectification bridge is prepared as forming master circuit by two sets of non-controllable rectification bridges and clamp five level inverter, selecting intermediate DC clamp capacity according system voltage level, using diode clamp five level structure as inverter and semiconductor switching component as master switch as well as using controller to generate PWM control signal by applying digital signal microprocessor as kernel.

The invention discloses a control method of a normal-pressure low-temperature plasma power supply and a power supply device. A technical route of outputting in a sequence of power-frequency alternating-current input (AC)->low-voltage rectification filtration (DC)->Buck transformer pulse width modulation and pressure adjustment (DC)->H-bridge high-frequency inversion (AC)->high-frequency isolation transformer boosting (AC), wherein a Buck transformer is used for controlling the duty ratio of pulse width modulation by a negative feedback signal U of output voltage of the Buck transformer and carrying out automatic voltage stabilizing; and in the H-bridge high-frequency inversion step, an H-bridge inverter is used for controlling a current peak value of the pulse through a negative feedback signal I of input current of the H-bridge inverter. The control method disclosed by the invention can be used for flexibly adjusting the peak value of a discharge electric field, the peak value of discharge current and discharge frequency according to the process requirements, producing stable, uniform and soft low-temperature plastic under the normal pressure for treating surfaces of fabrics, rapidly restricting filament discharge from forming and avoiding the treated fabrics from penetrating and damaging accidently.

The invention provides a controller of a steering engine. The controller comprises a zeroing circuit, a steering engine feedback position circuit, a target signal conditioning circuit, a target angle and actual angle processing circuit, a direction control circuit, a signal selecting circuit, a PWM (Pulse-Width Modulation) signal generating circuit, a PID (Proportion Integration Differentiation) conditioning circuit, a carrier signal generating circuit, a signal isolating circuit, an over-current protecting circuit, a current sampling circuit, a power pipe driving circuit, an H bridge inverter circuit, a current sampling circuit and a power supply circuit. According to the controller of the steering engine provided by the invention, the common elements are adopted, so that the cost is reduced; with the adoption of the mature technology, the reliability can be ensured; and a PID control technology, a PWM control technology, a target signal and actual signal processing technology, an over-current protecting circuit technology, an isolating technology and the like are achieved by adopting discrete electronic elements; and as an experiment shown, the controller of the steering engine has the characteristics of being quick in response and good in tracking and meets the performance of controlling the steering engine.

The invention provides a power unit and a frequency converter. The power unit comprises a rectifying part, an energy storage capacitor connected with a direct current bus in parallel, and an H bridge inverter formed by four IGBTs (insulated gate bipolar translators); the rectifying part consists of two rectifying diodes and the other four IGBTs, the two rectifying diodes are connected with one phase output end of a secondary edge winding of a phase-shifting transformer, and the other four IGBTs are respectively connected with the other two phase output ends of the secondary edge winding; or the rectifying part consists of four rectifying diodes and the other two IGBTs, the other two IGBTs are connected with one phase output end of a secondary edge winding of a phase-shifting transformer, and the four rectifying diodes are respectively connected with the other two phase output ends of the secondary edge winding. According to embodiments of the invention, the rectifying software control difficulty can not be increased, and the IGBTs are under the work status of inversion by controlling the switching on/off of the IGBTs in the rectifying part, so that the electric energy generated by a motor can be fed back into a power grid.

The invention discloses a power equilibrium control method for reducing DC voltage fluctuation of a cascaded H-bridge inverter, and aims to solve the problem that power generation quantity is reduced caused by relatively large DC-side voltage fluctuation. The power equilibrium control method comprises the following steps of controlling a total DC-side voltage to achieve tracking of a maximum power point voltage of the DC-side voltage of each H-bridge unit and obtain an active current instruction value of a system; controlling decoupling of a network-side current, where independent control on an active current and reactive current can be achieved, and meanwhile, a total modulation wave voltage of the inverter is generated; and performing power equilibrium control between units, an accurate on-off state of each H-bridge unit is determined and power equilibrium control of each H-bridge unit and maximum power tracking of each H-bridge unit are achieved by sequencing an error of the DC-side voltage of each H-bridge unit. By the method, various working conditions can be adapted, stable running of the cascaded H-bridge photovoltaic inverter within a relatively large range can be achieved, moreover, the DC-side voltage fluctuation can be reduced, and the power generation quantity of the system is improved.

The invention discloses a three-phase power grid disturbance generating device and a control method thereof. The device comprises a three-phase multi-winding transformer, a power module array and an output filter which are connected sequentially, wherein the power module array comprises three groups of power modules corresponding to three-phase output; each power module comprises a three-phase PWM (pulse-width modulation) rectifier, a DC (direct-current) bus link and a single-phase H-bridge inverter which are connected sequentially; input of the three-phase PWM rectifiers is connected with secondary-side three-phase windings corresponding to the three-phase multi-winding transformer; each DC bus link comprises a DC capacitor group; output ends of the single-phase H-bridge inverters are cascaded to form device basic output; each group of power modules comprise at least one low-frequency disturbance generating power module for outputting fundamental waves or outputting the fundamental waves and harmonic waves as well as at least one high-frequency disturbance generating power module for outputting the harmonic waves. The device is controlled with the method. According to the method, the switching frequency of the at least one high-frequency disturbance generating power module is controlled to be not smaller than that of the at least one low-frequency disturbance generating power module. The device is small in size, low in cost and capable of meeting mobile, vehicle-mounted and on-site detection requirements.

The invention discloses an H-bridge inverter which is applied to an alternating current motor and outputs an output voltage of a power cell by allowing a cell controller compensating the power cell with an input voltage even if the input voltage changes. Users can select an operation mode of every cell controller as a compensation mode which is applicable for the input voltage and as an output voltage control mode according to simple instruction frequency. The cell controller provides a compensation control function for changes of the input voltage, thereby reducing communication loads between a main controller and a cell controller.

The present disclosure proposes an input power of each unit power cell of a cascaded H-bridge inverter that is mutually insulated. To this end, the present disclosure includes a phase shift transformer configured to output a voltage of predetermined phase by receiving an AC input power having a fixed frequency, and a plurality of unit power cells serially-connected configured to output a voltage having a predetermined phase by receiving a voltage provided by the phase shift transformer, wherein the phase shift transformer is configured to include the number of phase shifts corresponding to the number of the plurality of unit power cells.

The invention discloses a high-gain insulation-type three-level-type multi-path output DC-AC converter without a lost duty ratio. The front stage of the converter is a BOOST converter, the middle stage is an LLC resonant converter, the original edges of the LLC resonant converter are in parallel connection, the two paths of auxiliary edges of the LLC resonant converter conduct independent output,and the back stage of the converter is an H-bridge converter; the converter comprises two high-frequency insulation transformers, the original edges of the two high-frequency insulation transformers are in parallel connection and are connected to an LLC resonant network, the other end of the LLC resonant network is connected with a bridge-type circuit and a BOOST circuit in sequence, and the auxiliary edges of the two high-frequency insulation transformers are connected with a rectifying circuit and an H-bridge inverter in sequence respectively and conduct independent output. According to theconverter, the high-gain no-load voltage ratio is achieved through a three-level-type structure, electrical insulation of the original edges and auxiliary edges is achieved through a middle-stage LLCcircuit, and the safety is high; the duty ratio of the LLC circuit is not lost, the LLC circuit is easy to control, through independent output of the two paths of the auxiliary edges, the number of converters is reduced, and the cost is lowered.

The invention provides a method and device for detecting an initial position angle of an electro-excitation synchronous machine rotor, belonging to a control method and device of a motor. A three-phase power supply in the device is connected with an electro-excitation synchronous machine by a three-phase voltage source inverter; a voltage transducer is connected with a power line between the three-phase voltage source inverter and the electro-excitation synchronous machine; the voltage transducer is connected with an input end of a DSP (digital signal processor) control system; an output end of the DSP control system is connected with a PC (personal computer); a DC (direct current) power supply is connected with a rotor exciting winding of the electro-excitation synchronous machine by an H-bridge inverter; a current transducer is connected with a power line between the H-bridge inverter and the rotor exciting winding of the electro-excitation synchronous machine; and IGBT (insulated gate bipolar translator) drive signals are connected with the H-bridge inverter. According to the invention, the structure is simple and reliable, the realization is easy, the anti-interference performance is strong, the detection accuracy is high, the additional hardware overhead is not required, and the detection result of the initial position angle of the rotor can be acquired.

A blood pump system for left ventricle assist has an implantable pump unit having a multiphase stator having a plurality of windings connected between respective junctions for forming first, second, and third phases. An external control unit comprises an H-bridge inverter having first, second, and third phase legs. A percutaneous cable is provided having first, second, and third parallel pairs of redundant conductors. Each conductor pair is connected between a respective phase leg and a respective junction. The conductors are arranged concentrically around a cable core so that individual conductors of each pair are separated by at least one conductor of a different conductor pair.

The invention discloses a predictive current control method for a cascaded H-bridge inverter permanent magnet motor system. The method comprises the steps: connecting a surface-mounted permanent magnet synchronous motor to the three-phase output side of a cascaded H-bridge multilevel inverter, and establishing a discretization mathematic model in a complex vector form under a d-q coordinate system; acquiring a predicted current vector of a voltage vector actually acting in a kth control period under the action of a (k+1)th control period based on the model; constructing a value function according to the relationship between the current vector and the voltage vector increment; and determining the hysteresis width and the increment of an optimal voltage vector according to the amplitude andphase angle of a current error vector, and determining an optimal voltage vector of the (k+1)th control period according to an optimal voltage vector under the action of the kth control period. The prediction frequency and the value function optimization frequency can be reduced, the complexity of a multi-level model predictive control algorithm can be greatly reduced, and the method has better dynamic and stable performances.

The invention discloses a wind electricity-based electric energy quality series compensator. The wind electricity-based electric energy quality series compensator comprises a wind turbine, a synchronous generator, a rectification unit, a three-phase H-bridge inverter unit and a series transformer and is connected in series with a power grid; when the power grid runs normally, the electric energy quality compensator converts wind energy into electric energy and outputs power to load; when the voltage of the power grid drops or rises suddenly (surges) due to the failure of the power grid, the electric energy quality compensator outputs the corresponding compensating voltage, so that the voltage of the load end is kept unchanged; and therefore, the load can be protected from being influenced by the failure of the power grid. By using the wind energy, the problems in the energy storage of the conventional series compensator are solved; and the wind electricity-based electric energy quality series compensator has the characteristics that by wind energy generation and energy storage, the problem that the voltage drops and rises suddenly can be solved, and the electric energy quality is improved.