Chopper Circuit Research Articles

Photovoltaic Power System with MPPT Functionality for a Small-Size Electric Vehicle

Electric vehicles are recognized as the best replacement of petrol vehicles in the future. However, there are several problems hampering their development, such as the short life span of batteries, poor performance of start-up, and a short driving range. In order to resolve these problems, a hybrid power system based on photovoltaic (PV) cells, supercapacitors, and batteries is proposed. This paper focuses on PV cells using a maximum power point track (MPPT) system based on a BUCK chopper circuit. Moreover, a novel MPPT algorithm named sectional variable step climbing (SVSC) algorithm was proposed. To validate the proposed system, two main experiments have been done. The first experiment showed that the MPP of PV cells was tracked perfectly by use of this photovoltaic power system. The second one showed that the efficiency of SVSC was higher than two existing MPPT methods, the climbing algorithm and the open-circuit voltage (OCV) algorithm.

A Novel Integrated Magnetic Core Structure Suitable for Transformer-Linked Interleaved Boost Chopper Circuit

A novel integrated magnetic structure suitable for a transformer-linked interleaved boost chopper circuit is proposed in this paper. Coupled inductors with high coupling are known to be effective for downsizing magnetic components. However, it is difficult to obtain the optional leakage inductance with high coupling for coupled inductors with EE or EI cores because of the fringing effect in the air gap. In order to overcome this problem, a novel integrated magnetic structure is first proposed. Then, a design method for the coupled inductor with the proposed magnetic structure is introduced on the basis of the magnetic circuit model. Finally, the effectiveness of the novel magnetic core structure is validated and discussed from an experimental viewpoint.

Development of Wound Rotor Synchronous Motor for Belt-Driven e-Assist System

The automotive industry is showing widespread interest in belt-driven electric motor-assisted (e-Assist) systems. A belt-driven assist system (BAS) starts and assists the combustion engine in place of the conventional generator. In this study, a water-cooled wound rotor synchronous motor (WRSM) for the e-Assist system was designed and analyzed. The performance of the WRSM was compared with that of an interior permanent magnet synchronous motor (IPMSM). The WRSM efficiency can be improved for the BAS by adjusting the field flux at high speeds. The field current map to obtain the maximum efficiency based on the speed and torque was developed. To control the field flux via field current control in the WRSM, a general H-bridge circuit was added to the WRSM inverter to get the rapid current response in the high-speed region; the characteristics were compared with the chopper circuit. A WRSM developed for the belt-driven e-Assist system and a prototype 115 V power electronic converter to drive the WRSM were tested with a 900 cc combustion engine. The test results showed that the WRSM-type e-Assist system had good characteristics and could successfully start and assist the 900 cc combustion engine.

Research of Bipolar Micro-Arc Oxidation Pulse Power

the micro-arc oxidation technology is introduced in this paper firstly. The main circuit is designed according to the design demand. The main circuit is made up by chopper circuit and inverter circuit, the chopper circuit regulates the output voltage. Then the control circuit is designed, the control circuit include the key circuit, A/D converter circuit, driver circuit and LED display circuit.

Adaptive Acquisition of Power IGBT Transients With Discrimination Circuit

The frequency spectrum of the power insulated gate bipolar transistor (IGBT) circuit originates mostly from high gradient switching and low rate conduction components. High gradient transients are captured with direct probes. Switching losses are represented with 3-D surfaces acquired with Delaunay triangulation processing. Interpolation functions are introduced, allowing the prediction of the switching loss in the entire 3-D space. A chopper circuit is introduced for the acquisition of the IGBT low rate transients in the conductive stage of operation. A Zener discriminator enhances the measurement accuracy by two orders of magnitude. The experimental results are presented for a half-bridge converter. Measurement uncertainties are acquired with dc and impulse calibration apparatuses.

Cost Effective Wind Energy Conversion Scheme Using Self-Excited Induction Generator

This paper describes a laboratory model of a wind energy conversion scheme (WECS) using conventional cage rotor type induction motor of 3Hp, 3-Ø, 415V, 4.9A, 1440 rpm. A 220V, 20A separately excited motor coupled with the induction motor emulates the wind turbine characteristics. A 3-Ø, 415 V capacitor bank of 150μF is connected in each phase across the stator terminals of the machine for its self-excitation. As soon as rotor speed exceeds synchronous speed of the machine, it will generate electrical power and reach its rated value. This arrangement is called as self-excited induction generator (SEIG). To control the frequency of generated voltage, load-balancing technique is considered by using a three-phase diode rectifier powering to an additional load (dump load) through a d.c chopper circuit. Static reactive volt-ampere compensator (STATCOM) is used to mitigate the load reactive power requirement indeed magnetic reactance changes in the machine. Owing to cost optimization of STATCOM, additional reactor is connected across the stator terminals of the SEIG. Simulation study is completed using power system toolbox Matlab / Simulink version9.0. Experimental and simulation results are presented.

Evaluation of the Performance of a DC-Link Brake Chopper as a DFIG Low-Voltage Fault-Ride-Through Device

The performance of the doubly fed induction generator (DFIG) during grid faults is attracting much interest due to the proliferation of wind turbines that employ this technology. International grid codes specify that the generator must exhibit a fault-ride-through (FRT) capability by remaining connected and contributing to network stability during a fault. Many DFIG systems employ a rotor circuit crowbar to protect the rotor converter during a fault. Although this works well to protect the generator, it does not provide favorable grid support behavior. This paper describes an experimental investigation of an alternative FRT approach using a brake chopper circuit across the converter dc link to ensure that the dc-link voltage remains under control during a fault. Two different approaches to chopper control are examined and the resulting FRT performance is compared with that of a conventional crowbar approach. The new chopper-based control methods are experimentally evaluated using a 7.5-kW DFIG test rig facility.

Series-Connected IGBTs Using Active Voltage Control Technique

With series insulated-gate bipolar transistor (IGBT) operation, well-matched gate drives will not ensure balanced dynamic voltage sharing between the switching devices. Rather, it is IGBT parasitic capacitances, mainly gate-to-collector capacitance Cgc, that dominate transient voltage sharing. As Cgc is collector voltage dependant and is significantly larger during the initial turn-off transition, it dominates IGBT dynamic voltage sharing. This paper presents an active control technique for series-connected IGBTs that allows their dynamic voltage transition dVce/dt to adaptively vary. Both switch ON and OFF transitions are controlled to follow a predefined dVce/dt. Switching losses associated with this technique are minimized by the adaptive dv/dt control technique incorporated into the design. A detailed description of the control circuits is presented in this paper. Experimental results with up to three series devices in a single-ended dc chopper circuit, operating at various low voltage and current levels, are used to illustrate the performance of the proposed technique.

Analyses and Discussions on Novel Bilateral Chopper Incorporating ZVS

Various circuit technologies have been studied and developed. One of main streams concerns a soft switching technology to mitigate switching stress, leading to the reduction in switching losses or electro-magnetic noise. On the other hand, as a characterized orthodox technology, the existing chopper circuit is used for the electric vehicles, etc. Such technologies have a tendency to go out of vogue as power supplies for such vehicles. However, as a boost chopper for the battery charger for an electric vehicle, those technologies become a main stream, where a bilateral function is required. With the foregoing in mind, the authors have devised and analyzed the bilateral chopper using the soft-switch technology, which could be applied to a battery charger for an electric vehicle or similar

The NC Power Supply Design of Large Current and Wide Frequency Pulse in SEAM

There are a lot of ways to achieve large current pulse power supply, and the more common way is to adopt the inverter switching circuit to achieve pulse power supply. The core of the NC power supply design of large current and wide frequency pulse in SEAM is using two-stage modulation. Combined with inverter technology, DC chopper technology and NC technology, it not only can achieve the adjustability of the output pulse amplitude, but also can realize continuous adjustment of the output pulses and the duty cycle. The front stage of power supply uses DC/DC transformation circuit with the UC3879 integrated control chip as the core. With the microcontroller as the control core, the backward stage uses DC chopper circuit to achieve the NC power supply of multi-parameter adjustable output large current pulse . DOI: http://dx.doi.org/10.11591/telkomnika.v11i7.2812 Full Text: PDF

A Fully Differential Chopper Circuit in 130nm CMOS for Noise Minimization in Sensor Applications

For sensor applications, the bandwidth of interest is generally a few hertz. In this bandwidth, offset and 1/f noise are the dominant sources of error. Chopping technique is an efficient approach to decrease the 1/f noise and low-frequency offset of CMOS amplifiers; thus, in this paper, a proposed chopper circuit to tackle these problems is presented. The chopper circuit is designed using complementary CMOS switches that are optimized to achieve symmetric linear resistance in the range of input signal. The proposed circuit has a low ON resistance that only varies within 8% of its value for a rail to rail input. To validate its operation, it is used to build up a fully differential chopper stabilized CMOS amplifier powered at 1V. The resulting circuit achieves a thermal noise floor of 10 nV/√Hz and reduces the input referred noise corner frequency from 1-kHz to300mHz.

Plating pulse switching power based on a CPLD

This paper presents a method of using a CPLD to generate a PWM trigger pulse to a full bridge inverter and a chopper circuit. This method results in a very good high power and low voltage large current pulse plating power supply. A single-chip microcomputer is the core of the feedback control system. A fuzzy PID algorithm with SCM and CPLD complexes precisely controls the output voltage, allowing it to maintain a constant value. The system contains a protection circuit that detects output current and output voltage and can correct the system if it enters an over-current abnormal state, ensuring that the driving circuit can effectively drive the IGBT. The circuit is also protected by setting the inverter frequency and dead time of a digital PWM chip. This method for bidirectional pulse plating power supply digital control was verified to be correct and practicable by a Matlab software simulation.

Solar Power Conditioners Using Bidirectional Chopper Circuits Connected in Series

AbstractThis paper proposes a new high‐efficiency grid‐connection inverter suitable for the interface with thin‐film solar cells, which is composed of two bidirectional buck converters and an H‐bridge PWM converter connected in series. The switching frequencies of the first bidirectional buck converters are equal to the grid frequency, while the second is operated at twice the grid frequency. The combination of these two converters synthesizes an AC rectangular voltage pulse train from the DC input power. The H‐bridge PWM converter is operated at 20 kHz with a low DC capacitor voltage to compensate for the harmonic voltage included in the rectangular voltage pulse train. As a result, the proposed grid‐connection inverter makes it possible to reduce both switching loss and common mode voltage. Experimental results obtained by a 1‐kW single‐phase inverter demonstrate a high efficiency of 98% without any common mode voltage. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(2): 51–60, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22379

Voltage and Frequency Control of Wind Driven Stand-Alone Self-Excited Induction Generator Using DCMLC Based STATCOM

This paper describe the methods employed to control voltage and frequency of a 3-O stand-alone self-excited induction generator (SEIG) driven by a variable speed wind turbine. An attempt made to control the terminal voltage of SEIG by using a 3-O diode clamped multilevel converter (DCMLC) based STATCOM operation. A 3-O diode bridge rectifier with a d.c chopper circuit is employed to control the frequency of generated voltage. The VAr required by the load and the machine owing to changes in magnetizing reactance’s are compensated by DCMLC–STATCOM operate with full load excitation capacitance. To emphasis the controller characteristics, mathematical model of the controller is developed and implemented in MATLAB / SIMULINK software.

結合インダクタを用いた車載用昇圧チョッパ回路の特性解析と設計

結合インダクタを用いた車載用昇圧チョッパ回路の特性解析と設計

Miniaturization of a Transformer-Linked Multi-Phase Boost Chopper Circuit Using Boost Ratio Adjustment

This paper presents an approach to miniaturize a boost chopper circuit. The size of a switching power converter strongly depends on that of a capacitor and an inductor. A multi-phase boost chopper circuit composing a coupled inductor that can achieve miniaturization of an inductor and an output smoothing capacitor is proposed. It is important to adjust the relationship between the boost ratio and the duty ratio because the effect of miniaturizing a multi-phase boost chopper circuit varies depending on the duty ratio. In order to realize effective miniaturization of the proposed converter, this paper presents a scheme involving the adjustment of the boost ratio by a tapped inductor.

The NC Power Supply Design of Large Current and Wide Frequency Pulse in Short Electric Arc Machining

There are a lot of ways to achieve large current pulse power supply, and the more common way is to adopt the inverter switching circuit to achieve pulse power supply. The core of the NC power supply design of large current and wide frequency pulse in SEAM is using two-stage modulation. Combined with inverter technology, DC chopper technology and NC technology, it not only can achieve the adjustability of the output pulse amplitude, but also can realize continuous adjustment of the output pulses and the duty cycle. The front stage of power supply uses DC/DC transformation circuit with the UC3879 integrated control chip as the core. With the microcontroller as the control core, the backward stage uses DC chopper circuit to achieve the NC power supply of multi-parameter adjustable output large current pulse.

Stabilization Design of Digital Control for Multi-Phase Trans-Linked Type Boost Chopper Circuits

In recent years, compact and lightweight boost converter systems have been required in hybrid electrical vehicle and electrical vehicle applications. For miniaturization of passive circuit components, such as the inductor and the smoothing capacitor, a multi-phase method boost chopper circuit with a coupled inductor has been proposed and discussed. In this paper, the stabilization digital control design technique for the multi-phase method boost chopper circuit with a coupled inductor is proposed.

Direct AC-AC Step-Down Single-Phase Converter with Improved Performances

The paper presents two high-performance single-phase AC chopper circuits which perform AC-AC bidirectional direct conversion;one of them contains resistive loads and the other one is for inductive loads. It includes useful equations for chopper design. The correctfunctioning is tested by simulation.DOI: http://dx.doi.org/10.5755/j01.eee.18.10.1305

Current Filtration and Control of Wide-Ranged Speed Regulation AC Servo System

This paper carries research on the methods of wide-ranged speed regulation AC servo system based on the permanent magnetic synchronous motor. The permanent magnetic synchronous motor(PMSM) is a kind of motor with high speed and low rotational inertia, which needs overcoming nonsinusoidal magnetic field，cogging effect and the interference produced by chopper circuit when fulfilling wide-ranged speed regulation. In this paper, the authors analyze the phase current wave of PMSM, and put forth an appropriate type of digital filteration, which is proved true by computer simulation and experimental data.