A Digital–Controlled Soft-Start Circuit for Negative Output DC–DC Converter

2019 ◽  
Vol 28 (04) ◽  
pp. 1950067 ◽  
Author(s):  
Yan-Ming Li ◽  
Xiao-Li Xi ◽  
Hao Zhang ◽  
Zhong-Hui Chen ◽  
Jian Sun ◽  
...  

To suppress the inrush current and overshoot voltage generated at the start-up stage of Buck–Boost converter, a digital–controlled soft-start circuit based on digital-to-analog converter (DAC) control technology is proposed in this paper. The power consumption of the circuit is zero and the circuit is also keeps the characteristics of simple structure and high reliability. The circuit has been integrated into a Buck–Boost converter with negative voltage output by using the 0.18[Formula: see text][Formula: see text]m CDMOS high voltage process. The experimental results show that this circuit can effectively suppress the rush current, and the output voltage drops smoothly from 0 to the adjustment value, [Formula: see text][Formula: see text]V.

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
D. Kirubakaran ◽  
Rama Reddy Sathi

An isolated bidirectional full-bridge DC-DC converter with flyback snubber for supplying a resistive load is simulated and experimentally verified. The DC-DC converter for high conversion ratio, high output power, and soft start-up capability is presented in this paper. The circuit consists of a capacitor, a diode, and a flyback converter. These components help to clamp the voltage spikes caused by the current difference between the current fed inductor and leakage inductance of the isolation transformer. The switches are operated by soft-switching technology. The suppression of inrush current which is usually found in the boost mode start-up transition is presented here. The simulated and experimental results for output voltage, output current, and power for both buck and boost modes are presented.


Author(s):  
Pavlo Herasymenko ◽  
Volodymyr Pavlovskyi

This paper presents a soft start-up strategy of pulse-density-modulated series-resonant converter for induction heating application. The pulse-density modulation (PDM) technique is widely used in converters based on voltage-source series-resonant inverters (SRIs) to control the output current or power. However, during a start-up process, PDM has some disadvantages both in inrush current limiting and providing a zero-voltage switching operation of SRI transistors. In the paper, different PDM techniques are considered and basic moments of PDM using within the start-up process are analyzed. A new soft start-up strategy of PDM converter for induction heating application is proposed. The main features of the proposed strategy include an interleaved or a stepped PDM control, an initial combination of PDM at the beginning of the start-up process, and an operating algorithm during the start-up process. The proposed strategy was verified by a 2.5 kW experimental setup of the pulse-density-modulated interleaved converter with an operating frequency from 50 kHz up to 100 kHz. Experimental results confirm the effectiveness of the proposed start-up strategy and show that the maximum current amplitude within start-up processes exceeds the maximum steady-state current amplitude by no more than 30%.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4083
Author(s):  
Min-Soo Kim ◽  
Do-Hyun Kim ◽  
Dong-Keun Jeong ◽  
Jang-Mok Kim ◽  
Hee-Je Kim

Renewable energy needs are steadily on the rise. Bidirectional DC/DC converters are essential in charging and discharging various storage batteries, such as PV/ESS (photovoltaic/energy storage system). A dual active bridge (DAB) converter, in particular, transfers power in both directions by phase shift using a soiled state transformer (SST). To reduce switching inrush current in batteries under high voltages, a soft start-up is demonstrated during the initial switching operation. When a supercapacitor (SC) is used as a battery, the reverse power caused by the inrush current appears under high voltage at the DC-link side. This causes serious electrical damage to the PV/ESS’ boost converter and inverter. To suppress peak overshoot voltage and stabilize soft start-up transients, we propose a three-step soft start-up controller and algorithm for bidirectional DAB converter implementation at virtual ESS and UPS. The step-by-step control strategy by OLDC (open loop duty control), OLPSC (open loop phase shift control), and OLFC (open loop frequency control) provides a stable soft start-up operation. In the initial stage of the OLDC, the duty ratio is gradually increased by the PWM (Pulse width modulation) signal. In the middle stage, a phase difference is seen as per the voltage of the SC. The OLPSC is performed to reduce the phase difference. In the final stage, the OLFC is performed to smoothly control the small phase difference. The overshoot or inrush current is drastically suppressed toward the DC-link and SC module. Consequently, we demonstrate a proposed controller and algorithm with prototype 5 kW DAB converter.


2020 ◽  
pp. 15-23
Author(s):  
V. M. Grechishnikov ◽  
E. G. Komarov

The design and operation principle of a multi-sensor Converter of binary mechanical signals into electrical signals based on a partitioned fiber-optic digital-to-analog Converter with a parallel structure is considered. The digital-to-analog Converter is made from a set of simple and technological (three to five digit) fiber-optic digital-to-analog sections. The advantages of the optical scheme of the proposed. Converter in terms of metrological and energy characteristics in comparison with single multi-bit converters are justified. It is shown that by increasing the number of digital-analog sections, it is possible to repeatedly increase the information capacity of a multi-sensor Converter without tightening the requirements for its manufacturing technology and element base. A mathematical model of the proposed Converter is developed that reflects the features of its operation in the mode of sequential time conversion of the input code vectors of individual fiber-optic sections into electrical analogues and the formation of the resulting output code vector.


Author(s):  
Divya Singh ◽  
Aasheesh Shukla

Background : Millimeter wave technology is the emerging technology in wireless communication due to increased demand for data traffic and its numerous advantages however it suffers from severe attenuation. To mitigate this attenuation, phased antenna arrays are used for unidirectional power distribution. An initial access is needed to make a connection between the base station and users in millimeter wave system. The high complexity and cost can be mitigated by the use of hybrid precoding schemes. Hybrid precoding techniques are developed to reduce the complexity, power consumption and cost by using phase shifters in place of converters. The use of phase shifters also increases the spectral efficiency. Objective: Analysis of Optimum Precoding schemes in Millimeter Wave System. Method: In this paper, the suitability of existing hybrid precoding solutions are explored on the basis of the different algorithms and the architecture to increase the average achievable rate. Previous work done in hybrid precoding is also compared on the basis of the resolution of the phase shifter and digital to analog converter. Results: A comparison of the previous work is done on the basis of different parameters like the resolution of phase shifters, digital to analog converter, amount of power consumption and spectral efficiency. Table 2 shows the average achievable rate of different algorithms at SNR= 0 dB and 5 dB. Table 3 also compares the performance achieved by the hybrid precoder in the fully connected structure with two existing approaches, dynamic subarray structure with and without switch and sub connected or partially connected structure. Table 4 gives the comparative analysis of hybrid precoding with the different resolutions of the phase shifter and DAC. Conclusion: In this paper, some available literature is reviewed and summarized about hybrid precoding in millimeter wave communication. Current solutions of hybrid precoding are also reviewed and compared in terms of their efficiency, power consumption, and effectiveness. The limitations of the existing hybrid precoding algorithms are the selection of group and resolution of phase shifters. The mm wave massive MIMO is only feasible due to hybrid precoding.


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