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In this paper, an integrated transformer-less single phase boost inverter (SPBI) with high reliability for photovoltaic energy system is proposed. The proposed SPBI requires only three active switches and has the inherent features of shoot-through immunity and reduced leakage current, which improves reliability and cost of power conversion. Moreover, the proposed inverter can output ac voltage higher than the input dc voltage. The unified SPWM technique for the proposed inverter is also presented. The steady-state analysis, operating principles, and parameter selection guidelines are presented in detail for the proposed inverter. A laboratory prototype is built and tested to verify the performance of the proposed inverter.

High-cost isolators and their speed limits are the shortcomings of digital control in isolated power supplies. Different feedback schemes result in different numbers and speed requirements of the isolators, which impact the cost and the decision making. This paper compares existing solutions, and proposes a communication solution featuring data compression and time-division multiplexing, which provides the highest output accuracy and many advanced features of digital control, whereas the cost can potentially be in the range of conventional analog solutions.

A new control scheme for current distribution in parallel connected DC/DC converters was presented in this paper, which combined the proportional integral sliding mode (SM) control with the Master-Slave current sharing technology to achieve both current sharing and a better robustness in a parallel dc-dc converter. And the stability condition of the closed-loop system was analyzed by using small signal method. A parallel buck converter experiment platform based on FPGA was constructed. And the experimental results of the given proposed method are compared with the traditional double closed loop PI control. Experimental results were presented, showing good dynamic performance of the proposed control scheme.

A novel bipolar current source driver (CSD) for power MOSFETs is proposed in this paper. The proposed bipolar CSD alleviates the gate current diversion problem of the existing CSDs by clamping the gate voltage to a flexible negative value (such as -3.5 V) during turn-off transition. Therefore, the proposed driver is able to turn off the MOSFET much faster with a higher effective gate current. The idea presented in this paper can also be extended to other CSDs to further improve the efficiency with high output currents. The experimental results verify the benefits of the proposed CSD. For buck converters with 12 V input at 1 MHz switching frequency, the proposed driver improves the efficiency from 80.5% using the existing CSD to 82.5% (an improvement of 2%) at 1.2 V/30 A, and at 1.3 V/30 A output, from 82.5% using the existing CSD to 83.9% (an improvement of 1.4%).

The current-sharing technology based on Wireless communication allows the current of DC-DC parallel system to be divided equally very well. However, the information transmitted by the network inevitably exist a transmission delay, which makes the traditional system into a time-delay systems. This paper presents a method to comput the Critical Delay of a DC-DC Parallel delay system. The method uses frequency-domain techniques and the DC-DC Parallel System linearized average model to obtain the critical delay. Then a Simulation Model with two parallel modules was built. And the main circuit of the modules is BUCK converter. Finally using the MATLAB simulation tools, we demonstrate the correctness of the method.

The use of dc-dc converters connected in parallel is a suitable way to solve the technological problems that arise in large-capability power supply systems. This paper presents a new approach to parallel converters using double integral sliding mode control. This approach could alleviating the steady-state regulation error and enhancing dynamic current-sharing property by increasing the order of the proportional integral sliding mode (ISM) controllers using an additional integral term. Theoretical analysis and simulation results are provided for verification.

A small-scale experiment with a over-current silicon diode is presented and explained through a voltage-regulated switch model. The relaxation oscillation is proved through temporal behavior of the thin-beam drift in an infinite space. Moreover, the simulation made with nonlinear equation mathematical model, which is applicable to chaos,identified the experimental phenomena under certain initial normalized current values and parameters.

The operating principle of three-phase static VAR generator (SVG) with voltage source inverter (VSI) structure is analyzed in detail. Adopting a novel direct current control strategy under abc coordinate system, this paper realizes the rapid detection of system reactive current by applying instantaneous reactive power theory. On the basis of double closed-loop controlling method with voltage and current, the hybrid control approach based on the feed-forword control of grid voltage and DC voltage is proposed, which can eliminate the disturbance of grid voltage fluctuation and flicker and suppress the fluctuation of capacitor voltage at DC side effectively. The excellent static and dynamic performances of the system could be obtained. Finally, system simulation and experimental studies are performed respectively, and the results further verify the feasibility and effectiveness of the proposed control strategy.

Alternative switch combustion mode of air and gas is adopted on the two sides of the regenerative furnace, its temperature is in uncontrolled state in the switching process and the switch period is generally 3 ∼ 5 min. Thus, the conventional bi-cross limited combustion control method is no longer applicable to the object. This paper makes use of neutral network algorithm to adjust the static operating point. On this basis, fuzzy control strategy is used for the furnace temperature control. The actual application result shows that the control strategy is effective to solve the problem of the combustion control for regenerative furnace.

nowadays switch mode power supplies (SMPSs) have already widely adopted fully digital control. The paper proposes a concise and effective data transmission protocol based on the multi- resolution feedback method (MRFM) in the application of multiple isolated power supplies. The MRFM can compress sampling data of the 10-bit analog-to-digital converter (ADC) into the 4-bit code, and greatly improves the data transmission rate. The proposed data transmission protocol consists of data bits and address bits; data bits use the codes generated by the 4-bit/6-bit coding protocol, and address bits use the codes generated by the paired ones-complement code method; through the respective designs of data bits and address bits, the magnetic saturation problem of the pulse transformer is skillfully overcome. Simulation results verify the effectiveness and feasibility of the MRFM.

In the single-phase grid connected inverter, a power pulsation with twice the grid frequency is contained in the input power. In the conventional inverter, electrolytic capacitor with large capacitance has been used in order to decouple the pulsation. But, the electrolytic capacitor has a drastically shortened lifespan when used in high-temperature environment. This paper presents a single-phase grid connected inverter with a power decoupling circuit on the AC output. A most distinctive feature of the proposed system is that the ripple energy appeared on the input DC capacitor is transferred into the energy in an inductance on the additional decoupling circuit. Hence, the large electrolytic capacitor can be replaced by the small film capacitor. This paper presents the proposed topology and its control requirement. Finally, the new topology is verified through MATLAB simulation.

The node localization algorithm is one of the key technologies in WSN. In the paper, a Weighted DV-HOP algorithm is proposed based on traditional DV-HOP algorithm. And a improving simulation model is employed to confirm the changes of localization accuracy. Comparing DV-HOP algorithm, simulation shows that the WDV-HOP algorithm can increase localization accuracy by above 2% with the same conditions which includes the percentage of anchor node, the scope of radio range and the network connectivity. Conversely, under the same accuracy request, the number of percentage of anchor node can be reduced obviously to lower the network investment cost.

This paper presents a new single-phase grid-connected inverter with an active power decoupling circuit. In the conventional inverter, electrolytic capacitor with large capacitance has been used in order to balance the instantaneous input and output power. But, the life of the electrolytic capacitor is also greatly influenced by the temperature. This paper presents a new single-phase grid connected inverter that has an active power decoupling circuit. A most distinctive feature of the proposed inverter is that the ripple energy appears in the dc-link capacitor is processed by the active power decoupling circuit. Hence, the small film capacitor could substitute for the large electrolytic capacitor. Finally, the new inverter is verified through simulation.

In the micro-grid, the grid-connected inverter and its filter are important to convert and transmit the energy. In this paper, a T filter is used to reduce the harmonics of the grid-current. However, it will be lack of enough stability. In order to overcome this obstacle, a new passivity based controller, namely IDA-PBC is proposed in this paper. And the paper analyses the stability of the controller in detail. The correctness and validity of the proposed control algorithm are proved to achieve stability with good stability and dynamic ability by simulation and experimental results.

Using traditional voltage source driver, switching losses will be increased with increasing of switching frequency. A new circuit of interleaving BUCK converter using the current source driver is presented in this paper. Based on the current source driver, a new analytical loss model of the power MOSFET is developed. A non-linear parameter called Incremental Conductance is introduced to the model for analyzing switching loss more accurately. Finally, experimental results are presented for the CSD operating in an interleaving BUCK converter at 1 MHz, 12 V input, 1.3 V /25A output. The validity of the loss model is verified by experimental results.

A new kind of multi-function electric power quality calibration system based on virtual instrument is proposed in this article. This system integrates virtual instrument programming and power electronics together, generating diverse signals of current electric power quality field all-in one. The proposed system integrated signal generator unit can achieve 1) the acquisition of high-speed digital data; 2) D/A conversion; 3) unsymmetrical synchronal control; 4) analog output in four channels for optional design. This system generates diverse signals such as sine wave, triangle wave, square wave, stacking harmonic of 2–100 orders freely, square modulation wave, sag wave, etc. The experimental results prove that a significant accuracy and power improvement has been achieved in power quality misdistribution signal generating. At 0–300V voltage output with accuracy 0.05% and 0–10A current output with accuracy 0.1%. Overall, this calibration system will accelerate the steps of electric power quality.

The sliding variable structural control method has been used in DC/DC converter widely and show the excellent dynamic performance and the strong robustness, but the conventional sliding mode control, whose control rule is sign function, has some shortcomings, for which switching frequency is uncertain and control result is serious influenced by the sliding surface parameters and the circuit parasitic. In this paper, a novel fixed-frequency sliding mode control is proposed for control rule changed with duty cycle. The proposed method can make system worked at a fixed frequency, having better dynamic characteristics than the traditional sliding control. It is easy to realize with digital circuit after analysis. The correctness and validity of proposed control algorithm are proved by simulation results.

The sliding variable structural control method has been used in DC/DC converter widely and show the excellent dynamic performance and the strong robustness, but the conventional sliding mode control, which control rule is sign function, has some shortcomings, for which switching frequency is uncertain and control result is serious influenced by the sliding surface parameter and the circuit parastic. In this paper, a novel fixed-frequency sliding mode control is proposed for control rule changed with duty cycle. The proposed method can make system working at a fixed frequency, has the same good dynamic characteristics with the traditional sliding control, and is easy to realize with digital circuit after analysis. The correctness and validity of proposed control algorithm are proved by simulation and experiment results.

In this paper, resonant gate driver techniques for power MOSFETs are reviewed at first. To solve the exiting problems of the drive circuits previously proposed, new dual channel current-source gate drivers are presented here. The new drive circuits can achieve quick turn-on and turn-off transition time to reduce the switching loss of power MOSFETs significantly by constant gate drive currents due to the parasitic inductance, especially the common source inductance. A 12 V synchronous buck VR prototype at 1 MHz switching frequency was built to demonstrate the advantages of the new drive circuits. A significant efficiency improvement over the conventional gate voltage driver is achieved.

In this paper, a novel continuous reactive power compensator based on soft switching was discussed. Directed at the traditional electric power parameters measuring system didnpsilat have the managing ability of the modern operation system, a technology of AC synchronization sampling was given which was based on embedded microprocessor S3C44B0X with 32-bit ARM7TDMI core and muC/OS-square real-time operating system kernel. The technology divided the sampling process into 2-parts, frequency dynamic tracking and same-internal synchronization sampling .The multi-tasks, which task process the different priorities, used to actualize sampling the signal and treating with the data. All tasks were scheduled by the preemptive muC/OS-square kernel. The technology has decreased the conflict between the precision and real-time property. The ADS7864, a electric power application-specific A/D chip, has predigested the interface circuit. The hardware implementation has been outlined.

A novel power amplifier adopting switch-linear hybrid scheme (SLH-FWPA) is introduced to accomplish flexible waveforms power amplification in a high bandwidth at high output power rating. The final output stage of SLH-FWPA is derived from linear power amplifier architecture to maintain excellent output quality and well dynamic performance; and meanwhile using tracking power supplies for the linear output stage to acquire total system efficiency above 80% generally. Theoretic analysis for SLH-FWPA is given and experimental results verify the implementation of SLH-FWPA.

The principle of photovoltaic grid-connected generation system is analyzed, and the research on PWM control strategy is done based on the power output side of photovoltaic grid-connected generation system. The direct current control strategy of photovoltaic grid-connected inverter is presented. The control fashion of applying fixed switch frequency and the feedforward compensation control of utility grid voltage is introduced. The current response speed is proved to be faster, and the grid-connected current waveform is sine and the power factor is unity.

Typical topologies of Switch-Linear Hybrid (SLH) power converter are summed up by former research practices. The main frame, hybrid criteria, category classification and extension regulation for the development of SLH-topology are presented by practical examples. Different operation states by different devices are also discussed for applying the topologies reasonably. All the above will set up the foundation of the SLH to develop into a complete self-family in power conversion branches and obtain wide applications.