Advanced Materials Research Vols. 860-863

Abstract: This paper mainly introduces a new design about intelligent greenhouse control system based on system on a programmable chip, which is PSoC. This paper first introduces the current advanced characteristics of this system on a programmable chip PSoC with digital and analog mixed processing ability, and then focuses on the system structure, working principle, the realization of hardware module and software design method of the intelligent greenhouse control system based on PsoC platform.

Abstract: A PRE control scheme in single-phase inverter is adopted, namely connecting the proportional component with repetitive controller in parallel. This control scheme not only retains the characteristics of fast dynamic response from proportion link ,but also absorbs the advantages of no steady-state error in repetitive control .When the system is in stable operation condition, repetitive controller is used to resist periodic disturbance and thus improve the steady-state performance. Contrarily, the proportional component can feel mutation of input error and produce accommodation immediately to ensure the systems fast speed of response .The comprehensive theoretical analysis of this control strategy is given, and the system is designed in Matlab based on this theory, besides, the control scheme is achieved in the DSP platform by using digital control algorithm. Simulation and experimental results prove that the proposed scheme can achieve good dynamic and steady-state performance.

Abstract: The operation principle and the external characteristics in discontinuing current mode (DCM) are discussed for ZVS PWM Full-bridge Converter with current doubler rectifier (CDR ZVS PWM FB converter) .The converter operated in DCM remains the performances of the converter in CCM. This makes the converter achieve ZVS for the switches in a wide load range with the use of the energy stored in the output filter inductances, and the rectifier diodes commute naturally, therefore no oscillation occurs. Features of ZVS achievement for the switches in DCM are also included in this paper.

Abstract: A chaotic circuit was designed to simulate the chaotic phenomenon observed in power supply system of electric arc furnace (EAF). Based on volt-ampere characteristic of the negative resistance converter (NRC) composed of the integrated operational amplifier (IOA), two NRCs with different parameters are connected in parallel in this circuit. The positive and negative power supply sources of the IOA are unequal in voltage amplitude. Experimental results show that the circuit has characteristics of general Chuas circuits and can generate an asymmetric double-scroll chaotic attractor, which helps establish the foundation for chaotic model of AC arc furnace used to study power quality.

Abstract: In this paper, FPGA is chosen as the hardware design platform, on the base of sufficient analysis of ICX204AL's working principle and driving timing, the driving timing of CCD is described with Verilog HDL in the development environment of QuartusII 9.0. Finally, Modelsim SE 6.4a is employed to carry on the simulation to verify the accuracy of the design. The result shows that the driving circuit design can meet the demands of ICX204AL, and the CCD can work stably.

Abstract: In order to improve the efficiency of DC/DC converter and cut down its power loss, a novel pulse frequency modulation technique is put forward. Based on the traditional PFM, the turn-on time of the switch is reduced by current limit circuit in the case of light-load, short-circuit or other faults. Thus, the light-load loss and the short circuit current are diminished sharply. Applied the novel PFM technology, a monolithic DC-DC converter is designed, and the simulation analysis by Cadence and tape-out test results both verify the correctness and the feasibility of this design.

Abstract: In this paper, the working principle, the structure and the characteristics of an improved Boost circuit are introduced briefly, in addition, the simulation model of the improved Boost circuit is established using Multisim11.0, a simulation software of NI company. The results of the simulation verify the validity of the improved Boost circuit theory and establish the simulation model with optimal parameters. It also can be seen from the experimental results that the improved Boost circuit has a higher step-up ratio with the premise of no hardware upgrade. In general, the Multisim11.0 software plays an important role in the design of electronic circuits.

Abstract: The PBHC (Passivity Based Hybrid Controller, PBHC) with damping injection and neutral point potential balance was based on a dual-EL (Euler Lagrange, EL) model of three-level three-phase dual load NPC (Neutral Point Clamped, NPC) VSR (Voltage Source Rectifier, VSR) in dq reference frame. The simulation results from Matlab/Simulink show that the proposed control strategy has excellent performances: at the AC side, the THD (Total Harmonious Distortion, THD) is less than 5%, the PF (Power Factor, PF) is higher than 98%; at the DC side, the output voltage is able to track the desired voltage quickly, the capacitors votages are equal.

Abstract: The mathematical model of three-phase voltage sources Pulse Width Modulation (PWM) rectifier is nonlinear, in view of the traditional linear control strategys weak disturbance-rejection ability with resistive and inductive load, a new passivity-based control strategy was proposed according to passivity-based control theory. Energy shaping method based on PCHD (Port Control Hamiltonian with Dissipation) model and the IDA-PBC (Interconnection and Damping Assignment Passivity Based Control) control algorithm is adopted to design passivity-based controller, which is able to make the energy function have the minimum value when rectifier is at the desired point, thus improving the stability and the load disturbance-rejection ability. Simulation results show that passivity-based control method can make this system possess the high-performance of robustness and dynamic.

Abstract: A lower power consumption, smaller output ripple and better regulation buck dcdc converter controlled by voltage feedback and pulse-frequency modulation (PFM) mode is implemented in this paper. The converter operating in discontinuous conduction mode (DCM) is designed and simulated using the TSMC 0.18μm 1P6M CMOS Process. Hspice simulation results show that, the buck converter having chip size with power dissipation about 0.68mW. This chip can operate with input supply voltage from 1.2V to 1.8V, and switching frequency from 249KHz () to 50KHz (), and its output voltage can stable at 1.0V and less than 110mV ripple voltage at maximum loading current 100 mA.