Bipolar Output Research Articles

Performance of a Bipolar Output Voltage DC-DC Converter for Voltage Regulation for Solar PV System Application

Performance of a Bipolar Output Voltage DC-DC Converter for Voltage Regulation for Solar PV System Application

An Isolated Three-Phase AC–AC Converter With Bipolar Output Voltage

An Isolated Three-Phase AC–AC Converter With Bipolar Output Voltage

Power quality improvement of unipolar-input-bipolar-output DC transmission system via load power balancing

In DC transmission and distribution systems, both unipolar and bipolar transmission modes exist, and DC transformers used in these systems are also available in either unipolar or bipolar configurations. In actual systems, due to requirements such as economy, land occupation, and reliability, there is a tendency to use a system with unipolar input and bipolar output. However, the bipolar loads, if unbalanced, will lead to increased equipment costs and voltage imbalance, causing power quality problems. This paper defines the Power Unbalance Factor (PUF) to describe the power quality of the studied DC transmission system and presents an improved DC transformer topology based on a power balancing system. This topology realizes bipolar voltage balance and improves the power quality of the DC transmission system when the load is unbalanced. The influence of the proposed solution on the power design of the DC system is demonstrated through theoretical analysis, and its effectiveness for improving the DC power quality is verified by both simulations in MATLAB/Simulink environment and physical experiments. When the power electronic transformer needs to be overloaded, the proposed topology can reduce the design power of the two branches by using the difference power, which is economical.

Realization of modularized corrector magnet power supply with N+1 redundancy for TPS facilities

This paper delves into implementing multi-module parallel current output using the existing TPS storage ring correction magnet power supply. We have devised a control interface card with N+1 redundancy to facilitate bipolar high-current parallel module output. To achieve this, we have employed various current feedback methods, including external DC Current Transducer (DCCT) and internal module current feedback signals. Following PI compensation, these feedback signals are amalgamated with reference current signals to compute compensation values for each module, which are subsequently disseminated to each Corrector Magnet Power Supply (CMPS) for modulation, thereby enabling closed-loop current control. A single CMPS module can deliver ± 48 V/± 10 A output, while up to eight CMPS modules can be interconnected, yielding a maximum output of ± 80 A. Through numerous experimental measurements, the long-term output current stability remains within 0.6 mA, or 7.5 ppm, with the output current spectrum predominantly maintained within 500 μA. Furthermore, the system boasts N+1 redundancy functionality and bipolar output current characteristics. These exemplary performance attributes underscore the criticality of our design for future applications of TPS magnet power supplies.

A Novel Modulation Method to Decouple Output Power and Suppress Current Zero-Crossing Distortion for Vienna Rectifiers in Bipolar Output Mode

A Novel Modulation Method to Decouple Output Power and Suppress Current Zero-Crossing Distortion for Vienna Rectifiers in Bipolar Output Mode

Five-Port Isolated Bidirectional DC-DC Converter for Interfacing a Hybrid Photovoltaic–Fuel Cell–Battery System with Bipolar DC Microgrids

This paper introduces a novel five-port, three-input, dual-output isolated bidirectional dc-dc converter (FPIBC) topology with an effective controller for power-sharing and voltage-balancing in bipolar dc microgrids (BPDCMGs). The proposed converter acts as the interface for the integration of a hybrid generation system comprising a solid oxide fuel cell (SOFC), a photovoltaic (PV) system, and a battery into BPDCMGs. It employs a reduced number of circuit elements compared with similar multiport converter topologies suggested for BPDCMG applications. Symmetrical bipolar output voltages are ensured by a voltage-balancing circuit composed of a fully controlled switch and four diodes. The FPIBC is equipped with different controllers for output voltage regulation and balancing, power sharing, maximum power point tracking of the PV, the optimum operating region of the SOFC, and constant-current, constant-voltage charging of the battery. To verify the viability and effectiveness of the proposed system, a simulation model was developed with a 4.2 kW SOFC, a 3.7 kW PV, and a 140 V 10.8 Ah battery in MATLAB/Simulink. The performance of the FPIBC was evaluated through extensive case studies with different operational modes, including battery charge/discharge states and SOFC and PV parameter changes under varying load conditions. In addition, the proposed system was examined using a daily dynamic load profile. According to the simulation results, a peak efficiency of 97.28% is achieved and the voltage imbalance between the output ports is maintained below 0.5%. It is shown that the FPIBC has advantages over previous converters in terms of the number of ports, number of circuit elements, bipolar output voltage, bidirectional power flow, and efficiency.

New Coupled-Inductor High-Gain DC/DC Converter With Bipolar Outputs

This paper presents a new bipolar step-up DC/DC converter with the capability of decreasing the input current ripple for renewable energy applications. Two power switches with the simultaneous operation are used in the proposed converter. The suggested topology can provide positive and negative output voltages in a quadratic form with the same and different voltage levels and common ground. The bipolar outputs of the presented topology can be varied independently using the duty cycle and tuning the turn ratio of the coupled inductor (CI). Moreover, the maximum voltage stress across the switching components is much lower than the output voltage. This topology operates under soft-switching conditions for the second switch and all diodes. The steady-state and the main operating equations of the converter are also derived. Finally, a 210 W prototype with 110 V, -110 V, and 220 V output voltages is implemented to justify the theoretical analysis and performance operation of the proposed converter.

Two Proposals of a Simple Analog Conditioning Circuit for Remote Resistive Sensors with a Three-Wire Connection.

This article proposes and experimentally characterizes two implementations of a novel front-end circuit for three-wire connected resistive sensors with a wire-resistance compensation. The first implementation relies on two twin diodes, whereas the second on a switch; in both cases, those devices are non-remote (i.e., they are placed at the circuit end). The two circuit proposals have a square-wave input excitation so that a constant current with the two polarities is alternatively generated. Then, depending on that polarity, the current goes through either the sensor and the wire parasitic resistances or just the parasitic resistances. This generates a square-wave bipolar output signal whose average value, which is obtained by a low-pass filter, is proportional to the sensor resistance and only depends on the mismatch between two of the three wire resistances involved. Experimental tests applied to resistances related to a Pt100 thermal sensor show a remarkable linearity. For example, the switch-based front-end circuit offers a non-linearity error lower than 0.01% full-scale span, and this is practically insensitive to both the presence and the mismatch between the wire resistances.

Analysis and Simulation of Three-Input DC-DC Converter with Bipolar Symmetric Outputs

This paper presents a three-input high-gain DC-DC converter with bipolar symmetric outputs. The advantages of a bipolar DC grid are higher reliability, flexibility, and efficiency as compared with the unipolar DC grid. Therefore, the proposed converter is designed to connect directly with the bipolar DC grid due to its bipolar symmetric outputs. The three input voltage sources to the converter are operated in a sequential manner from the first voltage source to the last one, with each source providing power at a level proportional to its duty cycle. Similarly, when the sources are equal, they operate in a sequential manner with their specific power. In addition, the proposed converter is designed to provide the required power to the grid under both simultaneous or individual from three input voltage sources. A double-loop PI controller is applied to regulate the converter output voltages and the control loop is analyzed and the transfer function relating reference voltage to output voltage is derived. Voltage balance control is provided to ensure that the outputs remain symmetrical despite changes in load conditions or input voltage. A converter with a power rating of 1000W and output voltage levels of 200V, -200V, and 400V is designed. The three supply voltage of 150V,100V, and 75V are used. The converter is tested under a variation of supply voltages and load using MATLAB/SIMULINK. The results show the feasibility and effectiveness of the proposed converter.

Improved Dual Active Bridge DC–DC Converter With Symmetric Bipolar Output by Utilizing a Switched-Capacitor Circuit for Bipolar DC Distribution System

The bipolar dc distribution system is a promising solution due to its advantages in efficiency and reliability, but there are also challenges of pole voltage imbalance. By using a simple switched-capacitor circuit, this paper presents a semi-dual active bridge converter with symmetrical bipolar output characteristics. The converter is capable of single-stage power conversion, offering the advantages of low cost and high-power conversion efficiency. Moreover, the symmetrical bipolar output voltage can be achieved without an additional voltage balancer and feedback control under unbalanced load conditions, which reduces system cost and control system complexity. In addition, the proposed converter also has a significant advantage over existing solutions in terms of the number of semiconductor devices and magnetic components. A detailed analysis of the proposed converter is presented, including the operation principle, steady-state performance, soft-switching performance, voltage gain, voltage/current stresses, efficiency and loss analysis, and control method. Finally, a 1-kW prototype is developed and tested to verify the performance of the proposed converter.

A new soft‐switching high gain DC/DC converter with bipolar outputs

AbstractThis paper introduces a new single‐input multi‐output step‐up DC/DC converter with soft‐switching performance and low input current for renewable energy applications. The proposed topology uses a three‐winding coupled‐inductor (TWCI) and voltage multiplier circuits to achieve high voltage gains. The bipolar output voltages of the proposed converter can be varied independently by tuning the turns ratios of the TWCI. Due to the semi‐trans‐inverse specification of the suggested topology, high voltage gains can be obtained under a lower number of turns ratio in the magnetic device. Furthermore, a regenerative passive clamp technique mitigates the voltage stress on the single power switch. Additionally, the power dissipations are further reduced by considering a resonant tank in the circuit. In the converter, the parasitic leakage inductances of the TWCI windings help to provide the soft‐switching conditions for the switch and also to eliminate the reverse‐recovery loss for all converter diodes. The operating mode of the presented converter has been introduced and the steady state, along with the main operating equations have also been derived. Finally, the theoretical analysis is verified by a sample prototype 235 W at the input voltage 25 V and outputs of 200 V and −200 V.

Development of linear power operational amplifier power supply with pre-regulated voltage controller for TPS correction magnets

The Taiwan Photon Source (TPS) is a renowned 3 GeV synchrotron accelerator light source. Over the past decade of successful operation, it has demonstrated outstanding performance, notably in average beam trip downtime, meeting international standards. A continuous regimen of scheduled equipment upgrades has been maintained across all subsystems to ensure ongoing improvement and the preservation of an optimal research facility environment. The central focus of this study revolves around the design and realization of a TPS correction magnet power supply employing Linear Power Operational Amplifiers (LPOA) in conjunction with a pre-regulated voltage controller. The power source predominantly features APEX Corporation's PA05 LPOA, characterized by bipolar output, high internal power dissipation, and wide bandwidth. Additionally, a DC Current Transducer (DCCT) was employed as the current feedback element, integrated with the pre-regulator voltage controller to form a closed-loop current modulation circuit, providing the variable voltage required by the LPOA. Through these measures, we have successfully developed an LPOA power supply unit equipped with a pre-regulated voltage controller for TPS correction magnets. The prototype device boasts a maximum output current of ±10 A, operating at 24 V. Validation through control loop design has led to rapid and stable output current performance. The output current ripple is maintained within 100 μA, with a rise time of 75 μs during step response. During frequency response testing utilizing a 0.1 V disturbance signal, the gain margin resides within -3 dB at an 11.2 kHz bandwidth and the phase margin within -45∘ at a 5.1 kHz range. Long-term output current stability is sustained within ten ppm. Finally, a hardware prototype circuit has been constructed in the power supply laboratory, featuring a ±24 V input voltage and ±10 A output current, achieving a maximum rated power of 240 W.

Bipolar segmented photonic digital-to-analog converter with wavelength multiplexing and balanced detection.

Photonic digital-to-analog converters (PDACs) with segmented design can achieve better performance than conventional binary PDACs in terms of effective number of bits (ENOB) and spurious-free dynamic range (SFDR). However, segmented PDACs generally require an increased amount of laser sources. Here, a structure of bipolar segmented PDAC based on laser wavelength multiplexing and balanced detection is proposed. The number of lasers is reduced by a half compared to a conventional segmented design with the same nominal resolution. Moreover, ideal bipolar output with no direct-current bias can be achieved with balanced detection. A proof-of-concept setup with a sampling rate of 10 GSa/s is constructed by employing only four lasers. The PDAC consists of four unary weighted channels and four ternary weighted channels. The measured ENOB and SFDR are 4.6 bits and 37.0 dBc, respectively. Generation of high-quality linear frequency-modulated radar waveforms with an instantaneous bandwidth of 4 GHz is also demonstrated.

Study of Bipolar Inductively Isolated High-Voltage Pulse Source

To meet the application requirements of pulsed power technology in wastewater treatment and other aspects (for example, a scenario that requires a high-voltage pulse source that can output a pulse with a rising edge in the nanosecond range and a device that can stabilize the pulse under high-frequency conditions), this paper designed an inductively isolated bipolar high-voltage pulse source. It consists of three parts: the primary charging power supply, the isolated driver circuit, and the pulse-forming circuit. By using inductance instead of traditional resistance isolation, using the inductance for charging and isolation, the inductance can increase the charging voltage of the capacitor, so the circuit can achieve a higher voltage output. The dual-Marx generator parallel connection design of the pulsed power supply topology, using a primary charging power supply for positive and negative polarity charging, can simultaneously output the reverse polarity and size of high-voltage pulses to achieve a bipolar output, so the load has an effect on the pulse. The equipment was selected on the basis of the design of the isolated driver circuit, primary charging power supply circuit, and pulse-forming circuit for the corresponding simulation, and in the experiment to build a principle model, the tests showed that the pulse source output pulse amplitude range was 0~10 kV (the positive pulse voltage was 5 kV, and the negative pulse voltage was −5 kV), the pulse rising edge was approximately 200 ns, the pulse width was 1 μs, and the frequency range was 0~1 kHz for the pulse source frequency. The power supply was designed to be used in applications such as wastewater treatment.

Contribution to the Development of a Smart Ultrasound Scanner: Design and Analysis of the High-Voltage Power Supply of the Transmitter

A smart ultrasound scanner plays an important role in the transition to point-of-care imaging. DC–DC bipolar converters are essential in the generation of the ultrasound burst signal as they power the piezoelectric transducer. The conventional bipolar converter has minimal output gain and high-voltage stress, and the longer duty cycle on the semiconductors produces high conduction losses and reduces the efficiency of the system. The transmitter supply voltage is minimal, necessitating the use of high-gain bipolar converters. This proposed study is concerned with the development of an improved high-output voltage gain symmetric bipolar DC–DC converter topology which may be suitable for applications such as powering a smart ultrasound scanner transmitter. The proposed converter combines the conventional single-ended primary inductor converter (SEPIC) with a voltage multiplier cell (VMC) to improve voltage gain, transistor duty cycle, efficiency, and reliability. The present study describes the working principle of the proposed converter. The analysis of the voltage gain is carried out in continuous current mode (CCM) and discontinuous current mode (DCM), taking into account the nonidealities of the device. The simulation of the proposed system is carried out in the numerical environment Matlab/Simulink in order to verify its characteristics. A prototype model is realized and the experimental study presented validates the theoretical arguments and simulations. Due to the advantages of continuous input current, self-balancing bipolar outputs, and small component size, the proposed converter is a suitable choice for smart ultrasound transmitters.

Soft-Switching Resonant DC Transformer for Class-D Switching Amplifier With Symmetric Bipolar Outputs

In this letter, soft-switching resonant DC transformer (DCX) for the class-D switching amplifier with the symmetric bipolar outputs is proposed. The proposed DCX consists of a single transformer primary inverter circuit and two transformer secondary dual series resonant half-bridge rectifier circuits, which reduces the voltage stress of the rectifier diodes. In the proposed DCX, the duty cycle of the primary inverter circuit is 0.5, and the symmetric bipolar output voltage gains only depend on the transformer. By dual series resonance between the leakage inductance and the output resonant capacitors, ZVS turn-on of switches and ZCS turn-off of the diodes can be achieved, which improves the overall efficiency. The characteristic of the DCX is elaborated and analyzed in this letter. Finally, a 60 W prototype is established and the experimental verified the theoretical analysis of the proposed DCX.

Single-Switch Non-Isolated Resonant DC-DC Converter for Single-Input Dual-Output Applications

This paper describes a new configuration of Cuk and SEPIC (Single-Ended Primary Converter) ZVS-QR (zero-voltage switching quasi-resonant) combination DC-DC converter for bipolar output with a single switch. The proposed topology employs a single ground-referenced power switch, which simplifies the gate drive design with a single L-C resonant network and provides a bipolar output voltage with good regulation, acceptable efficiency and a step-down/up conversion ratio. This configuration provides dual-output voltage by switching the power switch to zero voltage, which is an interesting alternative for many applications where small size, light weight and high power density are very important aspects. In order to verify its performance, a SEPIC–Cuk Combination ZVS-QR prototype with a cost-effective commercial resonant controller was designed and tested. The experimental results show that the proposed combined topology is suitable for Single-Input Dual-Output (SIDO) applications.

Realization of an extended switched-capacitor multilevel inverter topology with self voltage balancing

Achieving high voltage levels is an important issue in the design of multi-level inverters (MLIs). In this paper, the basic unit of a new switched-capacitor (SC) topology is extended to achieve higher voltage levels with fewer components. The capacitors are charged from the single supply voltage directly by turning on appropriate switching states, which can generate a high-amplitude nearly sinusoidal output voltage. The operating principles, modulation strategy, method of determining capacitance, and power loss of the extended structure are presented in detail. Also, a comparative study with recent similar structures has been done. The extended SCMLI has the advantages of self-balancing the voltage of the capacitors, generating a bipolar output voltage, and satisfying the standard of harmonics (IEEE519). The experimental test and MATLAB simulation results of a 17-level prototype are given to verify the performance of the extended structure.

A Family of Symmetrical Bipolar Output Converters Based on Voltage-Multiplying Rectifiers for Interfacing Renewable Energy With Bipolar DC Microgrid

The bipolar dc microgrid system is considered a greatly promising solution to interface various renewable energy sources and emerging loads due to its advantages in efficiency and reliability. However, pole voltage imbalance and lack of superior bipolar power conversion topologies limit the development and application of bipolar DC microgrid systems. In this context, this paper proposes a family of multi-port converters based on voltage-multiplying rectifiers to achieve symmetrical bipolar output voltage and power conversion between renewable energy sources and bipolar buses. In the proposed topologies, single-stage power conversion, without voltage balance feedback control, and a low number of components are obtained. Furthermore, the bulky balancing inductor is eliminated to improve conversion efficiency and reduce the volume of the system. Moreover, the higher voltage gain, smaller input current ripple, and lower voltage stress of semiconductor devices make it ideal for interfacing renewable energy sources with bipolar DC microgrids. The derivation method for the proposed topology family is first introduced. Then, a typical topology in the proposed converter family is analyzed in detail as an example, including the operation principle, steady-state performance, parasitic parameter effects, design considerations, efficiency analysis, control method, loop designing, etc. Finally, a 1-kW prototype is developed and tested to verify the performance of the proposed converter.

Design, Development, and Performance Evaluation of GMR-Based Current Sensor for Industrial and Aerospace Applications

The article presents the development of an open-loop current sensor using indigenous multilayered giant magnetoresistance (GMR-ML) technology. The proposed current sensor consists of a magnetic core with an air gap, a GMR sensor chip, and a bias magnet. A GMR chip is biased with a permanent magnet to obtain linear bipolar output characteristics. The GMR chip measures the magnetic field produced in the air gap as a result of the current flowing through a conductor. The sensor design and characteristics were optimized and verified using both simulation and experiments. Several prototypes were fabricated and tested for the current range of ± 25 A. Experimental results indicate the sensitivity of the order of 0.165 mV/V/A with the temperature dependence of the sensitivity – 0.28 %/°C and bandwidth of 100 kHz. The fabricated prototypes were further compensated for temperature-dependent drift in sensitivity and offset in the temperature range of – 25 °C to 85 °C. The compensated sensor exhibits a sensitivity of 80 ± 0.5 mV/A with the temperature dependence of the sensitivity of 0.005 %/°C. The change in offset voltage of compensated sensor was less than 10 mV across the temperature range. The compensated prototype sensor shows a total output error of less than 1 % over the operating temperature range. Further, the performance of the sensor was evaluated for aerospace applications and compared with the existing current sensor. The comparative data shows an equivalent performance during the test.