Nowadays it is popular to use digital control in power supply design.A PFC project based on average current control is presented. Hardware and software of the control system are analyzed.The simulation results of Matlab confirm that the circuit parameters are appropriate.A laboratory prototype based on TMS320LF2407A is presented.The test results validate a good performance of the digital implementation under the AC line voltage variation,with the switching frequency 50 kHz.

Digital Control of Power Factor Correction

This article advises a simple high voltage-gain boost converter for interfacing a low voltage renewable energy source to high voltage DC-link. The proposed converter could produce high quality input/output powers, which reduces the losses and filtering requirements in input/output stages. The article introduces also a thorough mathematical analysis for the operation theory of the proposed converter. Moreover, the dynamic performance of the proposed converter is investigated for two distinct cases: driving a PV module at maximum power point under different climatological conditions and interfacing an energy storage element to DC-link. The internal model control technique is used here for tuning the proportional integral controller. The proposed converter and its controller are simulated in Matlab Simulink dynamic platform. The simulation results for different operating scenarios of the proposed DC/DC converter confirms its salient merit in producing high value/quality DC voltage.

Simple high voltage-gain DC/DC boost converter for renewable energy sources interfacing

In this study, a device for measuring the action potential of cardiac cell sheets was developed. The action potential was measured using a device comprising a 2-µm-thick parylene film with a silver electrode printed on it, which was referred to as the “electronic sheet.” The thin parylene film exhibits high biocompatibility and flexibility. Therefore, it demonstrates promise for biomedical microelectromechanical system applications. In this study, a cell sheet was used because the interest it had garnered in regenerative medicine for creating cardiac tissue in vitro similar to that in vivo. A high-efficiency drug development system can be realized by combining cell sheet technology and fabricating a flexible electronic sheet. The action potential of a cardiac cell sheet from a rat was measured using the as-developed flexible electronic sheet.

Simple action potential measurement of cardiac cell sheet utilizing electronic sheet

In this paper a novel approach is that the switches in parallel used to develop a interleaved boost dc-dc converter and pulse width modulation integrated circuits (PWM ICs) are used in order to maintain phase difference between switching pluses are 180°. These dedicated ICs makes closed loop operation of interleaved boost converter(IBC). With the input voltage about 52V and the output voltage about 218V with it can drive the load about 500W, with an efficiency of about 90%. In place of battery it can be replaced by solar string and with four batteries of each 12V with high current rated can be used to drive high power load with continuous conduction mode(CCM) of operation. In the following simplified schematic is included along with proposed circuit, the input and output filters can be smaller due to ripple current cancellation. Authors of this contribution report a simulation and hardware results of proposed topology of a two stage IBC with it has been shown that the size and cost can be minimized, possible extension to multiple topologies is indicated.

Development of interleaved boost dc-dc converter with closed loop control

Buck converter with LC input filter has the inherent PFC properties when operating in discontinuous capacitor voltage mode (DCVM). Due to the continuous capacitor voltage mode (CCVM) cannot be fully eliminated in power cycle, a good PFC effect also cannot be guaranteed which is the key for the application of Buck PFC. In this paper, the DCVM model for Buck PFC converter with LC filter has been constructed. Then, a dual-model switch passivity-based control is proposed to optimize the PFC based on the DCVM model and the CCVM model. Simulation results show the validity of DCVM model and a better PFC performance that has been achieved by proposed control method.

A new switching signal optimizing control for buck PFC converter with LC filter

In recent years, improving of power factor and reducing harmonic distortion in electrical instruments are needed In general, a current conduction mode boost converter is used for active PFC (Power Factor Correction) In a PFC boost converter, if a duty ratio, a load resistance and an input voltage are changed, the dynamic characteristics are varied greatly This is the prime reason of difficulty of controlling the PFC boost converter In this paper, a robust digital controller for suppressing the change of step response characteristics and variation of output voltage at a DC-DC buck converter load sudden change with high power factor and low harmonic is proposed Experimental studies using a micro-processor for controller demonstrate that this type of digital controller is effective to improve power factor and to suppress output voltage variation

Design of robust digital controller for interleave PFC boost converter with DC-DC converter load

In recent years, improving of power factor and reducing harmonic distortion in electrical instruments are needed. In general, a current conduction mode boost converter is used for active PFC (Power Factor Correction). In a PFC boost converter, if a duty ratio, a load resistance and an input voltage are changed, the dynamic characteristics are varied greatly. This is the prime reason of difficulty of controlling the interleaved PFC boost converter. In this paper, a robust digital controller for suppressing the change of step response characteristics and variation of output voltage at a DC-DC buck converter load sudden change with high power factor and low harmonic is proposed. Experimental studies using a micro-processor for controller demonstrate that this type of digital controller is effective to improve power factor and to suppress output voltage variation.

Robust digital control for interleaved PFC boost converter using approximate 2DOF

A robust DC---DC converter which can covers extensive load change and also input voltage changes with one controller is needed. Then the demand to suppress output voltage change becomes still severer. We propose an approximate 2-degree-of-freedom (2DOF) digital controller which realized start-up response and dynamic load response independently. The controller makes a control bandwidth wider, and at the same time makes variations of the output voltage small at sudden changes of a load and an input voltage. In this paper, a new approximate 2DOF digital control system with additional zeros is proposed. Using the additional zeros, the second-order differential transfer characteristics between equivalent disturbances and a output voltage are realized. Therefore, the new controller makes variations of the output voltage smaller and the sudden changes of the load and the input voltage. This controller is actually implement on a DSP and is connected to the DC---DC converter. Experimental results demonstrate that this type of digital controller can satisfy given severe specifications with low frequency sampling.

Yuji Fukaishi

Papers

Design of robust digital controller for interleave PFC boost converter with DC-DC converter load

Robust digital control for interleaved PFC boost converter using approximate 2DOF

Robust digital control of a DC---DC buck converter with low frequency samplings