Lian Xiaoqin

Design of MPPT algorithm under partial shadows

Owing to the complexity of the photovoltaic system structure and their environment, especially under the partial shadows environment, the output characteristics of photovoltaic arrays are greatly affected. Under the partial shadows environment, power-voltage (P-V) characteristics curve is of multi-peak. This makes that it is a difficult task to track the actual maximum power point. In addition, most programs are not able to get the maximum power point under these conditions. In this paper, we study the P-V curves under both uniform illumination and partial shadows environments, and then design an algorithm to track the maximum power point and select the strategy to deal with the MPPT algorithm by DSP chips and DC-DC converters. It is simple and easy to allow solar panels to maintain the best solar energy utilization resulting in increasing output at all times. Meanwhile, in order to track local peak point and improve the tracking speed, the algorithm proposed DC-DC converters operating feed-forward control scheme. Compared with the conventional controller, this controller costs much less time. This paper focuses mainly on specific processes of the algorithm, and being the follow-up basis for implementation of control strategies.

Design and Implementation of the Ground Source Heat Pump Remote Monitoring System

In this paper, the composition of the remote monitoring system, ground source heat pump process flow, remote monitoring data and the comprehensive economic indicators are designed and analyzed with focusing on the mathematical model of economic indicators and data processing method. Through the WebAccess configuration software, it realizes the real-time monitoring of heating/refrigeration (winter and summer) systems and two economic indicators which are the energy efficiency ratio of heating/refrigeration system and the energy efficiency ratio of the hot water system can be calculated by day, week and month. Based on .NET platform, the test results show that the data-processing method of the remote monitoring system can process and analyze the provided data, and also can provide an efficient, reliable basis for the model of renewable energy model construction.

The Method of Soft Sensing Based on RBF Neural Network and Intelligent Control for Sewage Disposal Process

Soft sensing method was proposed for determination of effluent BOD from SBR and its principle was introduced, the method was based on the radial basic function (RBF) artificial neural network. The RBF neural network was trained and simulated by a lot of observed data, and the result showed that the RBF neural network may be used to fulfil soft sensing for effluent BOD from SBR, so as to create condition for real-time control of sewage disposal process, showing abroad perspective in application. The fuzzy control method for DO in SBR sewage disposal process was represented, and the aeration time and the energy consuming according to different DO curves were also studied. DO can be controlled in real time by the fuzzy logical to change the frequency of motor. Then we can adjust the concentration of DO according to different DO curves, and get the obvious advantages in shortening time of wastewater treatment and reducing energy consumed

A Soft Sensing Method Based on Process Neural Network

A new method of soft sensing based on process neural network (PNN) is proposed in this paper. PNN is an extent of traditional neural network, and it is a new configuration of artificial neural network put forward in recent years. The thesis discuss some modified algorithms for raising training speed of PNN, these algorithms are based on function orthogonal basis expansion which exist low-speed convergence in network training. An improved algorithm for BP network based on function orthogonal basis expansion in process neural network for soft sensing is researched. After increasing the normalizing rule on original algorithm, and introducing function momentum adjustment item and learning rate automatically adjustment method for network weight function, which has means of zero and standard deviations of one, the training time of learning algorithm for process neural network is reduced, and a good effect is represented by simulation in wastewater treatment system

Versatile PSIM Simulation Model for Photovoltaic Array with MPPT Function

A Versatile simulation model for photovoltaic array is developed based on the DC physical model of photovoltaic (PV) module under PSIM environment. The I-V, P-V characteristics of photovoltaic array with different combina-tions can be simulated by the model. In addition, the model includes the function of Maximum Power Point Tracking (MPPT) and completes the simulation of the perturbation and observation method. It is concluded from the analysis of simulation results that high accuracy of the model simulation can accurately reflect the physical characteristics of the photovoltaic, and will provide a basis for the simulation of the power generation systems.

Design of Photovoltaic Inverter System based on TMS320F28027

The paper presents a Photovoltaic (PV) Inverter System based on TMS320F28027 that can not only achieve single phase DC/AC converting by a full-bridge inverter, but also realize the function of same phase-frequency between sine waveform generated from PV Inverter System and the reference waveform from grid. Furthermore, the single phase DC/VC converting is controlled by means of SPWM generated by taking advantage of the peripheral of TMS320F28027. In addition, PV grid-connected is made up of frequency tracking and phase difference detecting, which needs TMS320F28027 to capture the frequency and calculate the phase by pulse edge detecting according to feedback circuits that can transform sine waveform into pulse waveform. Consequently, PV Inverter System can make single phase DC/VC converting and PV grid-connected come true successfully.

Design and implementation of indoor environmental monitoring wireless sensor networks based on JN5139

In order to better meet the demand of monitoring indoor environmental quality in some applications, this paper presents a scheme of design and implementation of indoor environmental monitoring system based on JN5139 SOC. The system takes full advantages of ZigBee technology of JN5139 SOC chip in wireless sensor network design and implementation to realize the hardware design of wireless sensor nodes and construct Mesh-type sensor network using JENNIC ZigBee protocol stack. Based on above design, PC monitoring control terminal is expanded so as to realize the configuration of operation mode of sensor networks and sensor nodes. The test results show that the proposed system realizes the accurate monitoring of indoor environmental quality parameters such as temperature and humidity, density of carbon dioxide.

Ultrasonic Nondestructive Testing Signal Measuring and Processing System Based on VC

In order to improve the reliability and accuracy in using ultrasonic flaw detector, this paper designed a system for detecting the flaw detector performance parameters of the transmitter, to achieve the testing and calibration of parameters for detector output characteristics of the transmitter. The core of the system is the IPC, using acquisition card PCI-5124 to collect output signal of detectors transmitter. Based on VC++, this paper designed interface of output parameters for detectors transmitter, achieved the design of driver of acquisition card better and the design of detection algorithm has various parameters. Calibration results show that: the system completed testing and calibration parameters better, such as the pulse peak, pulse rise time and duration, pulse repetition frequency, center frequency and bandwidth, the equivalent output impedance transmitter.

Application of the Advanced Encryption Standard and DM642 in the image transmission system

AES encryption algorithm and digital signal processing (DSP) technology are used in image encryption transmission system to make sure the information security and confidentiality in this paper. The basic principles, structure of the algorithm and design skills are introduced and analyzed. The program design is realized in DSP environment. An overall scheme of the image encryption transmission system based on the DM642 platform is given and the DSP program design process is explained. The AES encryption running speed of image encryption transmission system in CCS environment is tested as well. Experimental results show that AES encryption algorithm and DSP technology can be applied to the real-time and secure image transmission.

The simulation algorithm for array of photovoltaic cells the maximum power point tracking based on the PSIM

The simulation algorithm based on the field of power electronics and motor control areas of application package software simulation (PSIM) for array of photovoltaic cells in a certain light maximum power point tracking (MPPT) had been built, different simulation step by analysis of the impact of MPPT. Simulation results show that: the model parameters of an array of photovoltaic cells correspond exactly with the actual parameters, therefore, the simulation can accurately reflect the actual physical characteristics, and it with high accuracy. To some extent, the simulation model for PV based on the PSIM completed the engineering simulation on demand; and the simulation model of the PV array MPPT algorithm also be proved effective.