Chopper Circuit Research Articles

Chopper‐Based Capacitor Voltage Equalization in Four‐Switch Split Capacitor Distribution Static Compensator With a Zig‐Zag Transformer

ABSTRACTA three‐phase four‐switch split capacitor distribution static compensator (FSSC‐DSTATCOM) with a zig‐zag transformer is used to mitigate current‐related power quality issues in the distribution system. In conventional DSTATCOM, a significant dc component of current diverges voltages across split capacitors, degrading the current tracking performance and increasing the source current THD. The proposed FSSC‐DSTATCOM with chopper circuit equalizes the voltages across split capacitors, improves the current tracking performance, and reduces the source current THD. Moreover, FSSC‐DSTATCOM reduces the switch count compared to conventional approaches that use more switches. In FSSC‐DSTATCOM, switching pulses for each switch are generated using hysteresis current control based on the reference filter currents derived from instantaneous symmetrical component theory (ISCT). The generation of switching pulses of chopper circuit is achieved by employing logical relational operator circuitry at the dc input side of DSTATCOM. Simulation and hardware implementation are used to verify the proposed FSSC‐DSTATCOM with the chopper circuit.

Design of a two-stage photovoltaic grid-connected system with dual closed-loop control

Abstract This paper designs a two-stage photovoltaic grid-connected system with dual closed-loop control, cascading the topological structures of photovoltaic cells, boost chopper circuits, and inverter circuits. The front-stage boost chopper circuit control utilizes the incremental conductance method to achieve maximum power point tracking control. The rear-stage inverter circuit employs a dual closed-loop control system with an outer voltage loop and an inner current loop, incorporating a proportional-integral controller, to ensure stable DC-side voltage and unity power factor for grid connection. A simulation model of the two-stage photovoltaic grid-connected system designed in this paper was constructed and analyzed through simulation runs. The firmness of the DC-side voltage and the achievement of unity power factor during grid connection confirmed the operability and resultiveness of the cascaded topology and the control method.

A high constancy and noise suppression voltage shift generator in SEIR-based BIST circuit for ADC linearity test

—The built-in self-test (BIST) circuit is designed to be highly integrated with ADC under test and tests the static linearity based on the stimulus error identification and removal (SEIR) method. A novel level shift generator is proposed for high-precision ADC testing to break the resolution limitation caused by thermal noise and non-linearity. The double sampling operation realized by the chopper circuits cancels the sampling kT/C noise, and the circuit further reduces the amplifier's thermal noise by reducing the noise bandwidth. Besides, this paper presents a new method to achieve a highly linearity-constant voltage shift by applying the negative-C technique. Implemented in 180 nm CMOS process, the simulation results show that the noise power of the voltage shift is reduced by 10 dB, and the constancy of voltage shift is only 3.7 ppm over the entire ADC input range. Benefitting from the noise and linearity performance enhancement, this BIST circuit can test 18-bit ADC to 18-bit accuracy level with one-tenth sampling points.

Marine magnetotelluric and controlled source electromagnetics signal simulative generator

Ocean bottom electromagnetic receivers (OBEMs) are invaluable tools for observing seafloor electromagnetic signals, primarily used in magnetotelluric (MT) sounding and marine controlled source electromagnetics (MCSEM). However, the high operational costs of deploying OBEMs require thorough pre-deployment testing to enhance the data reliability and quality. Commercial signal generators used for MT and controlled source electromagnetic (CSEM) testing often fall short of the restricted terms of the frequency range, signal-to-noise ratio, storage depth, time synchronization, and amplitude dynamics. To address these limitations, we developed a specialized marine MT and CSEM signal simulative generator. The generator employs pseudorandom number code-based white noise to simulate MT signals and uses multi-frequency synthesis and amplitude modulation (AM) to generate CSEM signals. The system is developed using a low-power microcontroller unit and a field programmable gate array platform, integrating various circuits such as power, clock, encoding, control, data storage, chopper, and amplification circuits. The generator simultaneously outputs four-channel white noise and AM signals. The white noise feature provides a wide and adjustable frequency band and amplitude, while the AM feature provides a large dynamic amplitude range and multi-frequency synthesis at various carrier frequency points. Comprehensive testing verified the performance of the proposed simulative generator. The test results demonstrate that the MT simulated signals cover a frequency range from 1 E4s to 100 Hz, providing adjustable amplitudes between 10 μVpp and 10 mVpp. The CSEM simulated signals include standard square waves, third harmonic waves, and seventh harmonic waves, with amplitudes adjustable from 10 mVpp to 10 Vpp. The proposed simulative generator enhances the efficiency of OBEM functional testing and provides essential equipment support for maintaining the quality of marine data.

Power-cycling degradation monitoring of an IGBT module with VCE(sat) measurement in continuous operation of a chopper circuit

This paper presents a power-cycling degradation monitoring method of an IGBT module with a VCE(sat) sensing circuit and junction temperature prediction by a three-dimensional structure model. A chopper circuit was introduced to provide a continuous-current-conducting operation of the IGBT module. The VCE(sat) sensing circuit with a low-cost IoT platform “Leafony” was utilized to monitor the junction temperature of an IGBT chip, which transferred the measured signal as digital data, and thus obtained a higher noise immunity than an analog-based circuit. The junction temperature of IGBT chip in the power module was analyzed from the dissipated power of IGBT and the transient thermal impedance between the chips and the ambient. This analysis is effective not only to observe the degradation but also to estimate the thermal resistance. Comparing the temperature profile between experiment and prediction provides health condition of the IGBT model.Predicted thermal profiles agreed with measured ones with 10 % increase of thermal resistance, which was degraded by a power cycle tester. From these results, the proposed monitoring method is effective to detect the progress of power cycle degradation.

Design and development of single-phase inverter for locomotives based on SVPWM

For locomotive in high-power inverter power supply output efficiency is low, the level is not stable, push-pull circuit before the switch tube of high pressure, low utilization rate of the original winding transformer problem, designed and developed a kind of single phase inverter power supply based on SVPWM control. The inverter is designed with a modular structure with a rated power of 4KW, which is used to supply power to the cab electrical apparatus and auxiliary air compressor at both ends of the locomotive. It is composed of a filter circuit, a front-end boost control drive circuit, a full-bridge DC boost circuit, an inverter control circuit, a voltage and current sampling circuit, a back-end full-bridge inverter circuit and a protection circuit. The front stage of the inverter adopts a full bridge chopper circuit topology, while the rear stage achieves SVPWM control through the Vacon NXS control box. Finally, a power supply prototype was produced through simulation verification, and the results showed that the designed power supply met the design requirements.

Design of modified reference phase modulation based boost chopper fed fifteen level stepped DC link hybrid converter

A new fifteen-level stepped DC to AC hybrid converter is proposed for Solar Photovoltaic (SPV) applications. A boost chopper circuit is designed and interfaced with the fifteen-level hybrid converters specific to Electric Vehicles’ Brushless DC Motor (BLDC) drive systems. In chopper units, the output of solar panels is regulated and stepped up to obtain the nominal output voltage. In the stepped DC-link hybrid converter configuration, fifteen-level DC-link voltage is achieved by the series-operated DC-link modules with reduced electrical energy compression. From the comprehensive structure, it is anecdotal that the proposed topology has achieved minimum switching and power loss. Elimination of end passive components highlights the merits of the proposed hybrid systems. The reduction of controlled power semiconductor switches and gate-firing circuits has made the system more reliable than other hybrid converters. From the extensive analysis, the experimental setup has reported that 7% reduction in harmonics and a 54% reduction in controlled power switches than the existing fifteen-level converter topologies. Mitigation of power quality issues in the voltage profile of a fifteen-level multilevel hybrid converter is achieved through the implementation of dsPIC digital-controller-based gate triggering circuits.

Modeling, Design and Control of Speed DC motor using chopper

An electric motor, a power controller, and an energy-transmitting shaft make up an electrical drive. Power electronics converters are utilized as power controllers in contemporary electrically driven systems. DC actuators and AC drives are the two primary categories of electric drives. This study presents design and modeling techniques for very effective individually stimulated DC motor speed control. A DC motor speed controller can be implemented using a chopper circuit as a converter. The controller transmits a signal into the chopper firing circuit, which in turn generates the desired speed of the chopper by varying the voltage supplied to the motor's armature.One type of controlling loop is the speed controller, and another is the current controller. A proportional-integral controller is used. Eliminating the delay with the aid of this controller makes rapid control possible. It creates a separately stimulated DC motor. A current and speed regulator are built in to give the DC motor high-speed control in a steady condition. Under different speed and torque conditions, the model is simulated and examined in MATLAB (Simulink). Results that are satisfactory are achieved, validating the capacity of the chopper approach to control the speed of a DC motor.

Development of nanosecond spike pulse power supply for electrochemical micromachining

The use of pulse voltage can greatly improve the precision of electrochemical microfabrication, and the narrower the pulse width of the applied pulse voltage signal, the higher the machining precision. However, the commonly used chopper circuit topology of pulse power supplies is limited by the maximum switching frequency of the field-effect transistor. To address this problem, this paper proposes a nanosecond pulse electrochemical micromachining power supply based on a differential circuit. The power supply uses the STM32F103C8T6 microcontroller as the control core to output high-performance rectangular waves through a DDS device. After differential, rectification, filtering, and power amplification processing, stable, frequency, amplitude, and pulse width adjustable spike pulse voltage signals are obtained. By establishing a system mathematical model and optimizing the time constant of the differential circuit, theoretically, the sub-nanosecond pulse width can be obtained. Prototype performance tests show that the power supply has a maximum frequency of 20 MHz, a minimum pulse width of 1.8 ns, and a maximum peak voltage of 10 V. By using this power supply for microhole electrochemical machining experiments, nanometer-level machining precision has been achieved.

Different Chopper Types for Supply Separately Excited DC Motor

Abstract Nowadays saving the planet’s resources plays a very important role in improving our life conditions. The purpose of the paper is to supply the separately excited dc motor by using different chopper circuits. A very sustainable solution is to replace the resistors from classic theory with dc choppers for better efficiency. The armature voltage can be controlled by using IGBT chopper and the PWM signal received from controller is done with a dedicated block created by MATLAB environment. The advantages of developing this technique are that the speed changes proportionally with armature voltage and inversely with field voltage by keeping field and armature voltage constant respectively. The chopper designed with IGBT and Diode modules offers good control at any frequency value and the speed, the armature current and electromagnetic torque of DC motor can be control. In this paper, different choppers had been simulating were working in four quadrants for supply an excited dc motor by using Matlab program.

FPGA-Based Hardware-in-the-Loop (HIL) Emulation of Power Electronics Circuit Using Device-Level Behavioral Modeling

Accurate models of power electronic converters can greatly enhance the accuracy of hardware-in-the-loop (HIL) simulators. This can result in faster and more cost-effective design cycles in industrial applications. This paper presents a detailed hardware model of the IGBT and power diode at the device level suggested for emulating power electronic converters on a field programmable gate array (FPGA). The static visualization of the IGBT component involves an arrangement of equivalent models for both the MOSFET and bipolar transistor in a cascading configuration. The dynamic aspect is represented by inter-electrode nonlinear capacitances. In an effort to expedite the development process while still producing reliable results, the algorithm for the simulation system was built utilizing FPGA-based rapid prototyping via the HDL Coder in MATLAB software (R2019b). Essentially, the HDL Coder transforms the Simulink blocks of these devices within MATLAB into a hardware description language (HDL) suitable for implementation on an FPGA. To evaluate the suggested IGBT hardware model and the nonlinear circuit simulation technique, a chopper circuit is replicated, and an FPGA-in-the-loop simulation is carried out to compare the efficacy and accuracy of the model with both offline simulation results and real-time simulation results using MATLAB Simulink software and the Altera FPGA Cyclone IV GX development board.

Control method of an AC-AC MMC for open-end stator winding wind turbine generation system

With the increasing of power rating and voltage level of wind turbine, the traditaional low voltage converter is being replaced by multilevel converter. This paper proposes a new ac-ac modular multi-level converter (MMC) connecting the open-end stator winding permanent magnet synchronous generator (OW-PMSG) to AC power grid. The working principle of the proposed topology is analyzed. Under different grid conditions, a unified capacitor voltage balance control method and a current control method are proposed. Aiming at the low grid voltage ride through problem, a distributed braking chopper circuit and the corresponding control strategy is given. Simulation is conducted for verification. Compared with the back to back (BTB) MMC for OW-PMSG, the number of capacitors and arm inductors of the proposed topology are reduced by 43% and 33%. Moreover, the number of the state variables of the average capacitor voltages and currents of the proposed topology are reduced by 33% and 47%, reducing the control complexity. The proposed topology also has higher efficiency than the BTB MMC for OW-PMSG. Compared with the other ac-ac MMC topologies for OW-PMSG, the combined power rating of the power devices of the proposed topology is much lower and thus the proposed topology has higher power density.

Research on coordinated control strategy of photovoltaic energy storage system

In this paper, the modular design is adopted to study the control strategy of photovoltaic system, energy storage system and flexible DC system, so as to achieve the design and control strategy research of the whole system of “photovoltaic + energy storage + DC + flexible DC”. This realizes the flexibility and diversity of networking. Due to space reasons, this article focuses on the detailed explanation of the photovoltaic energy storage system control strategy, including the maximum power tracking control strategy of photovoltaic power generation, photovoltaic power generation boost chopper circuit control strategy, photovoltaic power generation DC/AC converter control strategy, PCS device control strategy, PCS virtual impedance control algorithm, etc. Simulation experiments are carried out according to the specific case setting parameters. The simulation results prove that the proposed flexible DC system coordinated control strategy can ensure grid frequency stability and grid voltage stability, and improve the consumption capacity of distributed new energy.

Design and implementation of electrical engineering experiment based on the Arduino platform

Arduino platform is a new hardware and software combination platform that is widely used, flexible, easy to operate, and rapidly developing. In this paper, the design and implementation of the DC chopper circuit were conducted based on the Arduino platform. Firstly, the power signal and trigger signal are output in the form of programming on the Arduino platform, and the rest of the circuit is built on the breadboard in the form of hardware. Finally, the design waveform is obtained. This paper introduces the basic working principles of four power conversion circuits, conducts circuit simulation on MATLAB software and obtains the ideal output waveform, and uses C language programming to trigger control signal generation, generates corresponding electrical signals through compilation and USB wire transmission to Arduino controller, and builds relevant circuits. This paper makes use of the advantages of the breadboard, fully combines the theoretical knowledge and circuit connection, and finally observes the output waveform through an oscilloscope, and compares the waveform of the actual circuit with the simulation results of MATLAB.

Hybrid Energy Management System Consisting of Battery and Supercapacitor for Electric Vehicle

This paper is mainly focused on Hybrid Energy Management System (HEMS) consisting ofBattery (BT) and Super capacitor (SC). Two energy sources connected in with same DC link in parallel manner with the help of Bidirectional DC-DC converter, which is used to separate control of power flow of each source. Here Permanent magnet dc motor (PMDC) motor used as a load and speed control of PMDC motor can be done by PWM method for this purpose chopper circuit is used. Input of chopper circuit is DC link and output of the chopper is given to PMDC motor. This method of energy management gives power splitting between two sources based on State of Charge (SOC) of each individual source during different state of vehicle such as acceleration, constant running and deceleration. Improved filter-based power splitting techniques is implemented. Three acceleration reference points were taken for power splinting at different SOC levels of both energy sources. Objective of this proposed method is best use of both the sources i.e. battery and supercapacitor and maximum use of supercapacitor energy at the time of transient conditions. Battery supply energy during normal running condition or very less load condition. Hence during transient condition SC directly react with system and gives peak power requirement, so stress on battery is reduces hence lifetime of battery is increase, also power available during braking is store in SC and battery, so independence of Electric Vehicle (EV) is increases. Because of less peak power requirement, batteries with less peak output power is used so it is reduced size and cost of batteries. Matlab-Simulink software is used for simulation and also small scale hardware is also implemented of proposed method.

Modelling lithium-ion battery energy storage system for steady-state and transient analyses

Lithium-ion battery energy storage system (LiBESS) is widely used in the power system to support high penetration of renewable energy. To analyse its characteristics, this paper develops an electromagnetic transient model for representing its dynamics in either normal operation or fault conditions. Firstly, the lithium-ion battery model is established to reflect its external characteristics as well as to estimate the state of charge. Then, the different control strategies in normal integration and fault conditions are identified. The fault-ride-through strategy and negative sequence control strategy are activated during fault conditions to ride through the fault and avoid the double-fundamental-frequency (100Hz) fluctuation in the dc bus voltage. In addition, the chopper circuit is incorporated to safeguard the dc bus capacitor from breakdown probably caused by the high dc bus voltage. Finally, the effectiveness of the proposed method is verified with time-domain simulations under either normal or faulting scenarios.

L/HVRT scheme of offshore permanent magnet synchronous wind turbine

A low/high voltage fault ride through technology scheme of offshore permanent magnet synchronous wind turbine generator (PMSG) is proposed. When the offshore PMSG operates during low/high voltage faults, the reason for the unbalanced power generation between the generator side and the grid side is analyzed, and the jump mechanism of the DC bus voltage is explored. The chopper circuit is connected in parallel with the DC bus capacitor to dissipate the unbalanced power through the unloading resistance, stabilize the DC capacitor voltage and reduce its fluctuation. According to the low/high voltage ride-through technical standards of China, the inverter station control scheme for offshore PMSG is designed, and the reactive power compensation strategy is proposed. the feasibility and effectiveness of the proposed scheme is verified by simulation.

"Novel Method of Speed Control of 3 Phase Induction Motor by Chopper Circuit"

Power electronics advancements in recent years have had a significant influence on the functioning induction machine drives, as well as speed control My work provides a novel stinger approach for managing the pitch of a thirty motor. The speed of a three-phase inductor may be controlled using either a pm dc motor control technique or directly adding inertia to the stator winding, as per the documentation. My study is focused on developing a modern analogue synth controller system which allows regulating the frequency of a 3 electrical machine with transcending the limits of present methods. In this technique, a quadcopter circuit will be developed and when the helicopter's load current grows, the multiple impulse tire's pressure increased as well. On the MATLAB/Simulink framework, the same experiment will be run with turbine load resistance.

AC CHOPPER DESIGN AS UNIVERSAL MOTOR DRIVER BASED ON FUZZY LOGIC CONTROLLER

The electric motor has the function is converting electrical energy into mechanical energy. Based on supply, the electric motor is divided into two kinds of supply that are alternating current and direct current. The universal motor is an alternating current motor, the construction, and characteristics of a universal motor are the same as a direct current motor. Fuzzy Logic Controller is combined with AC Chopper circuit as a universal motor driver to control the motor universal speed at the stability of 1000 RPM and uses LM393 Optical Encoder sensor that will give a feedback signal to the fuzzy system as input. This research purpose is to implement AC Chopper as a universal motor driver to get more stable speed control combined with Fuzzy Logic Controller as feedback. In this study, the author uses the experimental method. With variable control are setpoint at 50% duty cycle and 1000 RPM speed reference of motor universal. Which is using 10 types of duty cycle values to get the average of driver efficiency and then using 2 kinds of load conditions for the controller test. The result of the driver test is to get speed control while without load condition has a period of 3 – 5 seconds to reach 1000 RPM. Then, when the load shedding condition has an overshoot value of up to 1193.33 RPM and reaches 1000 RPM in the range of 2 - 3 seconds. In this study, got the result of average driver efficiency is 85.41%.

An ultra‐low‐loss superconducting inductor for power electronic circuits

To break through the bottlenecks of the loss and size of conventional conductors and magnetic materials, replacing copper inductors by zero-resistance superconducting inductors can be a promising solution. The experimental, theoretical and numerical investigations into the loss characteristics of an air-core superconducting inductor have been carried out. All these results show that the loss from a superconducting inductor in the boost chopper circuit was reduced remarkably up to 373 times smaller than the loss from the magnetic-core copper inductor having the same conditions. Moreover, the actual volume and weight of the superconducting inductor are only 5.61% and 10.97% of those of the copper inductor having the same inductance and current capacities. Advanced numerical models have been built to verify the experiments that their results of superconducting losses as well as the current and frequency dependencies are well matched. A compact, low-loss and low-cost cryostat has been designed to accommodate the superconducting inductor, which can further improve the practicability for superconducting inductor to be equipped into various power electronic applications. The superconducting inductor can lead power electronic devices towards ultra-high-efficiency power conversion.