Soft Switching DC Converter for Medium Voltage Applications

Renewable energy sources such as solar and wind provide an effective solution for reducing dependency on conventional power generation and increasing the reliability and quality of power systems. Presented in this paper are design and implementation of a laboratory scale solar microgrid cyber-physical system (CPS) with wireless data monitoring as a teaching tool in the engineering technology curriculum. In the system, the solar panel, battery, charge controller, and loads form the physical layer, while the sensors, communication networks, supervisory control and data acquisition systems (SCADA) and control systems form the cyber layer. The physical layer was seamlessly integrated with the cyber layer consisting of control and communication. The objective was to create a robust CPS platform and to use the system to promote interest in and knowledge of renewable energy among university students. Experimental results showed that the maximum power point tracking (MPPT) charge controller provided the loads with power from the solar panel and used additional power to charge the rechargeable battery. Through the system, students learned and mastered key concepts and knowledge of multi-disciplinary areas including data sampling and acquisition, analog to digital conversion, solar power, battery charging, control, embedded systems and software programing. It is a valuable teaching resource for students to study renewable energy in CPS.

Section: Introductionmentioning

confidence: 99%

Design of a Laboratory Scale Solar Microgrid Cyber-Physical System for Education

Guo

Kors²

2021

“…Therefore, MOSFET power devices have been widely adopted in high efficiency power electronics. To improve the low-voltage drawback of MOSFETs in high-voltage applications, zero voltage switching, multi-level circuit topologies [10][11][12][13][14] have been developed and proposed to decrease conduction and switching losses. The phase shift pulse width modulation (PSPWM) and frequency modulation have normally been adopted to regulate duty cycle or switching frequency.…”

Section: Introductionmentioning

confidence: 99%

Analysis of a DC Converter with Low Primary Current Loss and Balance Voltage and Current

Lin

2019

Self Cite

A dc/dc pulse width modulation (PWM) circuit was investigated to realize the functions of reduced primary current loss and balanced voltage and current distribution. In the presented dc/dc converter, two full bridge pulse width modulation circuits were used with the series/parallel connection on the high-voltage/low-voltage side. The flying capacitor was adopted on the input side to achieve voltage balance on input split capacitors. The magnetic coupling element was employed to achieve current sharing between two parallel circuits. A capacitor-diode passive circuit was adopted to lessen the primary current at the commutated interval. The phase-shifted duty cycle control approach was employed to regulate load voltage and implement soft switching characteristics of power metal-oxide-semiconductor field-effect transistors (MOSFETs). Finally, the experimental results using a 1.68 kW prototype converter were obtained to confirm the performance and feasibility of the studied circuit topology.

“…Therefore, the presented converter has less component counts. Finally, the design procedure and experiments with a 300W laboratory circuit are presented and discussed to confirm the circuit analysis and converter performance.Electronics 2020, 9, 47 2 of 20 ZVS converters [24][25][26][27][28] can further eliminate the switching losses for medium voltage applications. However, the wide voltage operation is seldom discussed and investigated in conventional three-level soft switching converters.…”

mentioning

confidence: 99%

“…However, the wide voltage operation is seldom discussed and investigated in conventional three-level soft switching converters. The input voltage range of the three-level converter that is discussed in [20][21][22][23][24][25][26][27][28] is less than 4:1 voltage range operation. For some wind power or solar power applications, the input voltage of DC converters might be greater than 6:1 or 8:1 voltage range, i.e., V in,max ≥ 6 or 8 V in,min .A ZVS three-level DC/DC converter is discussed and then investigated to have 10:1 (80 V~800 V) wide input voltage operation and ZVS operation on active devices.…”

mentioning

confidence: 99%

Phase-Shift PWM Converter with Wide Voltage Operation Capability

Lin

2019

Self Cite

A soft switching three-level pulse-width modulation (PWM) converter is presented for industrial electronics with wide voltage range operation, such as solar power or fuel cell applications. Phase shift PWM scheme is used on the input-side to accomplish the zero voltage turn-on on power switches and improve the converter efficiency. Three-level diode-clamp circuit topology is adopted in the presented circuit to lessen the voltage ratings on active devices for high voltage applications. Three sub-circuits with the different turns-ratio of transformers can be selected in the presented converter in order to achieve 10:1 (V in,max = 10V in,min ) wide input voltage operation when compared to the conventional multilevel converter. The proposed circuit is a single-stage converter instead of two-stage converter to realize wide voltage operation. Therefore, the presented converter has less component counts. Finally, the design procedure and experiments with a 300W laboratory circuit are presented and discussed to confirm the circuit analysis and converter performance.Electronics 2020, 9, 47 2 of 20 ZVS converters [24][25][26][27][28] can further eliminate the switching losses for medium voltage applications. However, the wide voltage operation is seldom discussed and investigated in conventional three-level soft switching converters. The input voltage range of the three-level converter that is discussed in [20][21][22][23][24][25][26][27][28] is less than 4:1 voltage range operation. For some wind power or solar power applications, the input voltage of DC converters might be greater than 6:1 or 8:1 voltage range, i.e., V in,max ≥ 6 or 8 V in,min .A ZVS three-level DC/DC converter is discussed and then investigated to have 10:1 (80 V~800 V) wide input voltage operation and ZVS operation on active devices. The presented three-level converter has three winding turns and three auxiliary switches on the output-side to achieve wide voltage range operation. Three auxiliary switches on the secondary-side are active or inactive and three different turns-ratio of the isolated transformer are connected to the output load based on the input voltage value. Thus, three equivalent sub-circuits can be operated in the proposed converter to achieve wide voltage operation. Three-level neutral-point diode-clamp converter is adopted on the input-side to have the advantages of low voltage rating and soft switching operation on active devices and increase circuit efficiency. The phase shift PWM operation is used to control the active devices of three-level converter. The leading-leg switches are easily turned on under ZVS operation. The presented circuit has less component counts with better circuit efficiency to achieve 10:1 wide voltage operation when compared to conventional two-stage DC converters. The proposed converter has much wider input voltage operation range as compared to conventional single-stage DC converters with 2:1 or 4:1 voltage range (10:1 voltage range from 80 V~800 V). The paper is organized, as follows. Section 2 discusses ...