Showing papers on "H bridge published in 2007"

Inductance load controller

Abstract: PROBLEM TO BE SOLVED: To provide an inductance load controller that continuously and highly accurately detects a current flowing in an inductance load by adopting a switching sequence capable of reducing current ripples. SOLUTION: The inductance load controller is provided with a first current detection resistor (Rs1) interposed between one low-side switching element (3) in an H bridge circuit (BC) and a ground, a second current detection resistor (Rs2) interposed between the other low-side switching element (4) in the H bridge circuit (BC) and the ground, and a differential amplification means (7-1) for differentially amplifying a terminal voltage of each of the first/second current detection resistors (Rs1, Rs2). The differential amplification means (7-1) automatically adjusts a gain so as to make a correspondence relationship between a drive current when turning on each diagonal switching element (2, 3) in the H bridge circuit (BC) and the output of the differential amplification means (7-1) identical to a correspondence relationship between a back-flow current when turning on the low-side switching elements (3, 4) in the H bridge circuit (BC) and the output of the differential amplification means (7-1). COPYRIGHT: (C)2008,JPO&INPIT

A Novel Switching Sequence Design for Five-Level NPC/H-Bridge Inverters With Improved Output Voltage Spectrum and Minimized Device Switching Frequency

Abstract: This paper presents a novel switching sequence design for the space-vector modulation of high-power multilevel converters. The switching sequences are optimized for the improvement of harmonic spectrum and the minimization of device switching frequency. Compared to other commonly used switching sequences, the output spectrum of the proposed design shows higher inverter equivalent switching frequency. Meanwhile, the device switching frequency is reduced by using a flexible switching pattern. The proposed switching sequence has been simulated and experimentally tested on a 5-level neutral point clamped H-bridge based inverter. The results from both simulations and experiments consistently verify the above-mentioned features.

Using a cascaded H-bridge STATCOM for rebalancing unbalanced voltages

Abstract: This paper considers specific issues related to using the cascade (also known as the H-bridge) multilevel STATCOM with unbalanced voltages and currents at the STATCOM-AC line connection terminals. Under this condition the average power into the individual phase legs of the converter, in general, is not zero, although the total three phase power is zero. The resultant phase cluster power unbalance can result in increasing or decreasing capacitor voltages within a phase leg. This paper will present a technique for zeroing the phase cluster average power under unbalanced line conditions when the control strategy is to rebalance unbalanced voltages.

Design of Power Electronic Transformer based on Cascaded H-bridge Multilevel Converter

Abstract: One key component of the future automation in electrical network is the replacement of conventional distribution transformers by an all-solid-state (power- electronic) alternative. In this paper, the optimum design of a power electronic transformer (PET) based on state of the art cascaded H-bridge multilevel converter is investigated. In the design process, a new and simple control method for balancing the cascaded H-bridge DC buses has been introduced. The proposed PET is extremely modular and can be extended for different voltage and power levels. It performs typical functions and has advantages such as power factor correction, elimination of voltage sag and swell, and reduction of voltage flicker in load side. Also in comparison to conventional transformers, it has lower weight, lower volume and eliminates necessity for toxic dielectric coolants.

Observer for DC voltages in a cascaded H-bridge multilevel STATCOM

Abstract: Using an instantaneous model of a cascade H-bridge multilevel-based STATCOM, an observer for estimating the DC capacitor voltages of the multilevel inverter is presented. This design can be used to eliminate the voltage sensors in each H-bridge of this device. Simulation results are presented in order to validate the performance of the proposed observer applied to a cascade H-bridge multilevel-based STATCOM.

A Novel PWM Modulation Strategy for DC Voltage Balancing in Cascaded H-Bridge Multilevel Converters

Abstract: This paper presents a novel Voltage Balancing PWM modulation strategy for Cascaded H-Bridge multilevel converters. These converters have been classically commu-tated at fundamental line-frequencies, but the evolution of Power Semiconductors has allowed to increase switching frequencies and the power ratings of these devices, permitting the use of PWM modulation techniques. This paper presents a new PWM modulation strategy that solves the DC Bus voltage balancing problems that appear in the cascaded converter working in reactive power compensation (STATCOM) applications.

Inductorless DC-AC Cascaded H-Bridge Multilevel Boost Inverter for Electric/Hybrid Electric Vehicle Applications

Abstract: This paper presents an inductorless cascaded H- bridge multilevel boost inverter for EV and HEV applications. Currently available power inverter systems for HEVs use a DC- DC boost converter to boost the battery voltage for a traditional 3-phase inverter. The present HEV traction drive inverters have low power density, are expensive, and have low efficiency because they need a bulky inductor. An inductorless cascaded H-bridge multilevel boost inverter for EV and HEV applications is proposed in this paper. Traditionally, each H-bridge needs a DC power supply. The proposed inductorless cascaded H-bridge multilevel boost inverter uses a standard 3-leg inverter (one leg for each phase) and an H-bridge in series with each inverter leg which uses a capacitor as the DC power source. Fundamental switching scheme is used to do modulation control and to produce a 5-level phase voltage. Experiments show that the proposed inductorless DC-AC cascaded H-bridge multilevel boost inverter can output a boosted AC voltage.

Cascaded H-bridge Multilevel Inverters -A Reexamination

Abstract: Multilevel converters have gained popularity in high-power applications due to their low switch voltage stress and modularity. Cascaded H-bridge converters are a promising breed of multilevel converters which generally require several independent dc sources. Recently, existence of a redundant switching state has been utilized to replace the independent voltage sources with capacitors except for the one with the highest voltage level. Redundancy in the charge and discharge modes of the capacitors is assumed to be adequate for their voltage regulation. However, output current of the inverter as well as the time duration of the redundant switching states have been neglected. In this paper, the impacts of connected load to the cascaded H-bridge converter as well as the switching angles on the voltage regulation of the capacitors are studied. This study proves that voltage regulation is only attainable in a much limited operating conditions that it was originally reported.

Quick identification technique of fault conditions in cascaded H-Bridge multilevel converters

Abstract: With reference to multilevel converters in cascaded H-bridge configuration, the paper presents a technique suitable to quickly identify fault conditions during normal operations First a modulation technique generalized to m-level converters is synthetically illustrated in order to evidence the presence of different modulation patterns and the corresponding criteria of selection in normal operating conditions Then, all the "single- fault" conditions are classified, evidencing symmetrical situations, and some consequences on the converter voltage- vector star are analysed On this basis, a procedure is presented for on-line identification of the corrupted switching device and of the converter module where it is located No additional sensors are requested, because the procedure is based only on the values of phase-voltages and currents already detected for the closed loop converter control The fault identification is carried out in a few modulation intervals, also thanks to modifications automatically introduced in the modulation algorithm exploiting redundancies of different converter voltage vectors Numerical results are presented with reference to some significant fault conditions in cascaded H-bridge inverter having an assigned number of voltage levels

Multi-level frequency conversion driving apparatus with energy conservation unit

Abstract: The present invention belongs to the field of high voltage multilevel frequency conversion technology, characterized in that the main circuit composes of a H bridge series connection type frequency converter and a group of storage energy inverter devices. The H bridge series connection type frequency converter is powered by a multiple winding isolation transformer, the storage energy inverter device is connected with a passive power energy storage capacitor, the energy storage capacitor can be selected according to the corresponding system power level. The main switch device of the three-phase bridge arm of the frequency conversion driving device can choose the corresponding power semiconductor switch device according to the output voltage level and the different passing currents. The controller whose core is a high performance digital signal microprocessor forms the PWM control signal. The structure is added with a group of storage energy inverter devices in the base of the traditional H bridge series connection type frequency converter, so as to not only realize the purpose of using energy storage capacitor to store energy dynamically, but make the voltage harmonic content decrease, the present invention improves the efficiency and the performance of the frequency conversion driving device.

Comparison of single-phase matrix converter and H-bridge converter for radio frequency induction heating

Abstract: This paper compares the newly developed single-phase matrix converter and the more conventional H- bridge converter for radio frequency induction heating Both the converters exhibit unity power factor, very low total harmonic distortion at the utility supply interface, good controllability under soft switching condition for a wide range of power, and high efficiencies, whilst still having simple structures A novel switching control pattern has been proposed for the matrix converter in order to maintain the comparable performance to the H-bridge converter Simulation and experimental results for both converters are presented Comparisons between two converters have confirmed the excellent performance of the proposed matrix converter

A comparative analysis between the symmetric and the hybrid asymmetric nine-level series connected H-bridge cells inverter

Abstract: This paper presents the comparison of two cascaded multilevel inverter, with phase-voltage of the nine levels and applied to drive an induction motor of 500 kVA/4160 V. Performance indices used in hereinafter in the comparison are semiconductors power losses, total harmonic distortion and first order distortion factor. The comparisons are developed in three ways; in the first comparison the switching frequency is found. It guarantees that the converters present the same efficiency. In the second comparison the objective is finding the maximum switching frequency that it is gotten in each topology. Finally, in the third comparison, the efficiency which both systems present the same output filter is found.

A Sensorless Control of H-bridge Multilevel Converter for Maximum Power Point Tracking in Grid Connected Photovoltaic Systems

Abstract: There is a high development of grid-connected photovoltaic systems that utilize static converter which influence the efficiency of the system. The energy conversion depends on the architecture of the converter, different solutions are available and H-bridge multilevel converters seem to be an optimal solution also for the power quality. It is important to utilize a proper architecture of converter but also to set up a control optimized to have the energy conversion at maximum efficiency. The persistence of the maximum efficiency condition is related, depending on the atmospheric conditions, to the tracking of the Maximum Power Point (MPP) by modifying the operating conditions of the system (Maximum Power Point Tracking -MPPT). In the paper is proposed a sensorless control set up to deliver the maximum power to the grid in presence of variations of incident irradiation on the photovoltaic arrays. The control technique is presented and validated by simulation implemented on a photovoltaic system with H-bridge 5-levels converter. The simulation results confirm that the control is able to effectively track the MPP and to stabilize immediately in the new steady-state condition.

Method and circuit for driving H-bridge that reduces switching noise

Abstract: An H-bridge drive circuit for reducing switching noises while preventing shoot-through current from flowing in the H-bridge circuit. The H-bridge drive circuit includes an H-bridge circuit for driving a load with a first power supply and a lower voltage second power supply. The H-bridge circuit includes first to fourth transistors. The first and third transistors are connected to the first power supply. The second transistor is connected between the first transistor and the second power supply, and the fourth transistor is connected between the third transistor and the second power supply. The load is connected to a node between the first and the second transistors and a node between the third and the fourth transistors. A control circuit switches the activation and inactivation of the first to fourth transistors so as to maintain at least either one of the second and fourth transistor in an activated state.

Phase shifted H-Bridge resonant converter with symmetrical currents

Abstract: A phase shifted H-bridge resonant converter with symmetrical currents includes, a DC storage cap ( 31 ), four switches ( 1 - 4 ) with a parallel turn off network consisting of diodes ( 5 - 8 ), capacitors ( 9 ), ( 11 ), ( 14 ), ( 16 ), resistors ( 10 ), ( 12 ), ( 13 ), ( 15 ). The subsequent output of switches ( 1 - 4 ), is arranged in series with DC blocking caps ( 17 - 18 ), connected to a low mutually coupled inductor ( 32 ), an AC resistive load, capacitor ( 19 ), resistor ( 20 ) across inductor ( 32 ), with capacitors ( 22 ), ( 23 ) that comprise a resonant tank circuit, and is connected to the primary of transformer (21) wherein the interaction between the two coils of the low mutually coupled inductor ( 32 ) provides symmetrical currents within the switches and resonant tank circuit. Further, output rectification may be arranged by use of secondary winding of transformer ( 21 ), diodes ( 24 - 27 ), filter inductor ( 28 ), filter capacitor ( 29 ), and load resistor ( 30 ).

PWM rectifier in power cell of cascaded H-bridge multilevel converter

Abstract: This paper proposes to use PWM rectifier to replace the diode rectifier in the cascaded H-bridge multilevel converter in order to regenerate the power from the load to the grid. The rectifier in this paper employs the leakage reactance of the secondary windings of the input transformer instead of physical reactor because of the large number of the reactors needed by the PWM rectifier in a cascaded H-bridge multilevel converter. Voltage oriented control (VOC) is used to obtain the good performance of the control system.

Improved Performance and Control of Hybrid Cascaded H-bridge

Abstract: This paper presents capacitor voltage balance control methods for hybrid cascaded H-bridge inverter with single DC source to remove higher order of harmonics, the power quality is therefore improved with low THD of output power for utility interactive inverters. In addition, a new control strategy based on voltage frequency regulation is proposed in this paper to achieve faster and smoother transition from grid-connected mode to stand-alone mode. For sensitive and mission critical local loads, a seamless transition between two operation modes is very valuable, especially for the transition from grid-tied mode to stand-alone mode in the case of utility fault. The proposed method not only implement fast transition, the load voltage waveform also becomes continuous during transients. The proposed control methods can be easily applied for multi-bus micro-grid control system with least modification. The simulation and experimental results of single-phase utility interactive inverter confirmed the validity of proposed control algorithms.

Modulation Extension Control of Hybrid Cascaded H-bridge Multilevel Converters with 7-level Fundamental Frequency Switching Scheme

Abstract: This paper presents a modulation extension control algorithm for hybrid cascaded H-bridge multilevel converters. The hybrid cascaded H-bridge multilevel motor drive using only a single DC source for each phase is promising for high power motor drive applications since it can greatly decrease the number of required DC power supplies, has high quality output power due to its high number of output levels, and has high conversion efficiency and low thermal stress by using fundamental frequency switching scheme. But one disadvantage of the 7-level fundamental frequency switching scheme is that its modulation index range is too narrow when capacitor's voltage balance is maintained. The proposed modulation extension control algorithm can greatly increase capacitors' charging time and decrease the capacitors' discharging time by injecting triplen harmonics to extend the modulation index range of the hybrid cascaded H-bridge multilevel converters.

Zero-current notch waveform for control of a three-phase, wye-connected H-bridge converter for powering a high-speed electric motor

Abstract: A zero-current, synchronous switching waveform is provided for a three-phase, wye-connected H-Bridge to power an electric motor. The switching waveform includes two notches per cycle on the switching waveform provided to each of the semiconductor switches to minimize total harmonic distortion and switching loss. Positioning of the notch with respect to the zero-current crossing is optimized to reduce switching loss and minimize total harmonic distortion.

Water-exploring transmitter of ground nuclear magnetic resonant

Abstract: The presnet utility model relates to a ground nuclear magnetic resonance launching machine for the water detector, which is a high-power launching machine for directly water detection using the ground nuclear magnetic resonance technology. The microprocessor (1) which is connected with the H bridge circuit (3) via the driver circuit (2). The H bridge circuit (3) is connected with the transmitter current sampling (10) via the chime circuit (5), the diode module (6), the switcher (7) and the coil (9). The switcher (7) is connected with the radio (8). The microprocessor (1), the driver circuit (2) and the H bridge circuit (3) are supplied by the power source (4). The presnet utility model uses a low-power battery to supply a short-term high-power power supply, uses a rapid switch to facilitate the realization that the transmission on receiving use a common coil, uses a H-bridge circuit to realize the occurence of the alternating positive and negative pulses, and excites groundwaterd hydrogen protons to occur a magnetic resonance phenomenon. The presnet utility model simplifies the power supply design, and the device can rapidly absorb the residual transmission energy on the coil, and guarantee the validity of the signal receiver, and the utility model has a simple structure and is easy to operate.

Single output H-bridge drive

Abstract: Disclosed is a drive circuit for generating the drive current used to energize the windings of a motor The drive circuit includes a data processing unit that produces two outputs used to control an H-bridge and generation of the drive current One output, a commutation signal, controls the timing of generation of drive current The drive current in turn is determined based on the other output, a speed signal The speed signal waveform includes blanking portions to avoid occurrences of shoot through in the H-bridge

Passivity-Based Harmonic Control through Series/Parallel Damping of an H-Bridge Rectifier

Abstract: Nowadays the H-bridge is one of the preferred solutions to connect DC loads or distributed sources to the single-phase grid. The control aims are: sinusoidal grid current with unity power factor and optimal DC voltage regulation capability. These objectives should be satisfied, regardless the conditions of the grid, the DC load/source and the converter nonlinearities. In this paper a passivity-based approach is thoroughly investigated proposing a damping-based solution for the error dynamics. Practical experiments with a real converter validate the analysis.

Drive circuit for power element

Abstract: A driving circuit ( 1 ) for an IGBT ( 10 ) comprises an H bridge circuit ( 80 ) using first to fourth switching elements (Q 1 -Q 4 ). A control unit ( 20 ) switches the states of the switching elements from a first state in which the first and fourth switching elements (Q 1 , Q 4 ) are set to be in an on state and the second and third switching elements (Q 2 , Q 3 ) are set to be in an off state to a second state in which the first and fourth switching elements (Q 1 , Q 4 ) are set to be in an off state and the second and third switching elements (Q 2 , Q 3 ) are set to be in an on state when receiving an order to make the IGBT ( 10 ) transit from an on state to an off state. With the structure of the driving circuit ( 1 ) described above, reverse bias can be applied to the IGBT ( 10 ) by use of a single power source ( 15 ).

Underground metal pipeline detector emitter

Abstract: The utility model relates to an emission device using the electromagnetic method to detect the underground metal pipeline, wherein the main circuit is composed of a SCM and H bridge power amplifier chip, a consonance capacitance and emission loop; the SCM produces AC signals of different frequencies and amplifying the circuit by the power amplifier; the amplified signal passes the relay appliance to match different consonance capacitance so that the inductance and the capacitance serial resonance oscillation circuit are in the resonance oscillation status at different frequency points, thereby emitting the AC signal with a high efficiency. The mechanical emission signal frequency is variable and the emission power is adjustable at eight levels. The efficiency is high and the structure is simple, with a low cost, safety and stability, and the emission signal frequency and emission power can be put in the real-time display.

A New Multilevel Space Vector PWM Technique for H-bridge Cascaded Inverter

Abstract: A new multilevel space vector PWM method based on phase-shift SPWM technique and conventional three-level space vector PWM technique is proposed for H-bridge cascaded inverters. The proposed approach is developed for H-bridge cascaded multilevel inverters used for induction motor control. Using this technique, the implementation of software and hardware is greatly simplified. And it can be extended to higher level inverters easily. The proposed technique has been verified by simulations and experiments with a three-cell cascaded inverter.

Power quality problems in unbalanced operations of fault tolerant H-bridge multilevel active front-ends

Abstract: The paper deals with active voltage source rectifiers (PWM-VSR) having multilevel cascaded H-bridge configuration. With reference to operations with unsymmetrical supply voltages and/or unbalanced three-phase loads, some optimized control strategies are presented and compared. Particular attention is devoted to the most effective control algorithm in terms of distortion of the input-currents and limitation of the line-current unbalancing. The algorithms are represented by a set of algebraic equations able to generate in a very simple way the actual reference values for the dynamic control of VSRs. Some heavy transient operations are analyzed in order to show the validity of the proposed techniques and the capability to limit negative influence on the line power-quality indexes by means of optimized control of cascaded H-bridge active front-ends.

Method and apparatus for controlling a lifting magnet of a materials handling machine

Abstract: A magnet controller supplied by a DC generator controls a lifting magnet. Four transistors, forming an H bridge, allow DC current to flow in both directions in the lifting magnet. During “Lift”, full voltage is applied to the lifting magnet. During “Drop”, reverse voltage is applied briefly to demagnetize the lifting magnet. At the end of the “Lift” and the “Drop”, most of the lifting magnet energy is returned to the DC generator. A transient voltage suppressor protects against voltage spike generated when current reverses in the generator.

Electric booster steering controller

Abstract: This invented electromotive boosting turning controller including a microprocessor, an H bridge motor driving module, a motor, a resistor of sample feedback current and an electronic servo module, in which, the microprocessor is connected with a digital potentiometer via SPI bus bar, the motor driving signal output end of the electronic servo module is connected with the H bridge motor drive module. Advantage: applying an electronic servo module to carry out 2-way test to the feedback voltage signal provided by the sample feedback current resistor and the given voltage signal provided by the differential circuit so that the resistor can reflect the current of the motor really.

Vehicle electric booster steering system controller

Abstract: The force-assistance executor is a DC permanent magnet motor with brushes and supplies by 12 V battery system. The controller consists of micro-controller module, signal processing module, output control module, power supply module, relay with its driver module, H bridge module, grid driver module and motor current testing module. The characteristic of this invention is that the H bridge module adopts two P-trench type power electronic devices and two N-trench types. The source electrodes of the former lead to the positive terminal of the battery while the latter lead to the negative. The drain electrodes of each group of P type electronic devices are jointed to the drains of the same group of N type. Thus, the power supply module of the grid driver module needs no voltage-raising module. This simplifies the structure of the controller, lowers its cost and raises its reliability.

H bridge control system

Abstract: The utility model provides a H-bridge control system, which comprises a main controller MCU for controlling the positive or reverse rotation of motor, the motor speed and conducting different tests; a motor H-bridge driver and a protection circuit that drives the electromotor to realize required functions and protect the H-bridge driving circuit; a H-bridge driving circuit that drives the H-bridge driver, provides sufficient driving electricity to ensure the stable and reliable operation of H-bridge driver; a temperature testing circuit that applies to a plurality of testing units and temperature testing circuit of H-bridge driver and a motor current testing circuit and a battery voltage testing circuit; a module for communicating with a remote controller; the H-bridge driver, protection circuit, testing unit, H-bridge driving circuit and remote controller communication module are respectively connected to the MCU. The utility model is able to ensure the user to be informed of the operational status of product during the utilization, thus ensuring effective control.