Advanced Materials Research Vols. 383-390

Abstract: For engineering research, ECOSUNIDE technique was applied in a sewage treatment plant under low temperature and low carbon resource. The whole experimental system has being running steadily after reasonable adjustments of influent distribution, returned sludge ratio and DO. The effluent qualities meet the Class I-B Criteria Specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918-2002).Effluent BOD5 and NH₃-N meet the Class I-A Criteria. The results indicates that the treatment capacity could fluctuate within a range of ±3000 m³/d with DO properly controlled. In aerobic sections, the best DO was 2-3 mg/L. The optimal sludge emission amount could be attained through settlement ratio and sludge concentration with the present emission amount of sludge of 680 m³/d. It might be the restrictive factor that BOD/TN was less than 3 on TN removal which could not steadily achieve the Class I-A Criteria.

Abstract: Wind power is one of the cleanest and safest of all the renewable commercial methods of generating electricity. However, wind energy is difficult to use due to its stochastic variability. Energy storage can overcome the main drawback, allowing energy production to match energy demand. In this paper a new method is proposed to determine the Energy-storage Capacity in Grid-connected Wind Farm. Based on characteristic function of wind power output in wind farm, the method designs the minimum required storage capacity of the wind farm and realizes the stable output and the scheduling of wind farm. The results of this paper demonstrate the leading role of a well-optimized design for technical and economic viability of such systems.

Abstract: Rice stalk were pretreated using low concentration alkali and ultrasound combination pretreatment, biogas anaerobic fermentation were used to estimate the pretreatment. The results showed that daily mean biogas production using combined pretreatment stalk was 35.32-48.42% higher than that merely using low concentration alkali pretreatment stalk, 67.79-76.65% higher than that of unpretreated stalk. pH of fermentation broth showed no difference using different pretreatment methods. The content of lignin in lignocellulose were remarkably decreased when low concentration alkali and ultrasound combination pretreatment was used to deal with stalk, almost 41.01% lignin in stalk degraded.

Abstract: The purpose of this paper is to describe a solar array simulator to reproduce the I-V curve characteristics of solar panel modules using software. The simulator takes the storage data of I-V curves to use it as reference control to match the actual output of buck circuit with the selected module under test.

Abstract: According to characteristics of solar photovoltaic generation system, this paper presents a design of a single-phase photovoltaic grid-connected inverter about 1KW based on the digital signal processor TMS320F2812. This paper designs the algorithm of MPPT (Maximum Power Point tracking) and the algorithm of phase tracking according to its characteristics. The experiment is successful, and the output voltage wave of grid-connected inverter has the same frequency and phase with the grid voltage. The power factor of grid-connected inverter has reached to 0.99.

Abstract: This paper presents two phase-locked methods of wind power generation three-phase grid-connected inverter. First establishes the mathematical model of the inverter, on this basis analyzes why the power voltage phase must be known. And then studies the direct calculation method in α-β coordinates, and analyzes the shortcomings of this approach for three-phase imbalance; then focusing on the phase locked loop (PLL) approach in d-q coordinate system. To solve dynamic response problem of the PLL, a new signal delay cancellation method is put forward. With this improved method, the PLL can have a better performance. Experimental results show that the theoretical analysis is real.

Abstract: Heat supplies not only consume large amounts of energy, but also are very inefficient. However, in this case, a monitored control system which will realize 10% energy conservation in heat supplying is designed. This system has a two layer structure: one on-spot control layer and one upper supervisory layer. The former is exploited by PLC; the latter supervise and control the former via GPRS wireless communications. The Internet network will also in this system monitor any of the substations far away from the controlling centre. In this paper, the control scheme, hardware and software of the system will be introduced in detail. Until now, the system has been steadily running for more than 2 heating periods in the station and has pass all the relevant departments’ technical tests.

Abstract: This paper mainly introduces the energy-saving control strategy for coal-fired boiler heating system. The controlled objects of coal-fired boiler heating system includes the blowers of the boiler, the induced draft fan of the boiler, the chain for coal-carrying, the primary side water circulation and the secondary side water circulation. All the controlled objects are droved by electrical motors. By the optimal frequency conversion technical, more energy and coal can be saved.

Abstract: In this paper, based on the characteristics of battery management system, a monitor and control platform for battery management system was designed, using Kvaser Leaf bus analyzer and CAN bus technology. Test shows the platform has well performance in data monitoring, control strategy optimization and hardware test.

Abstract: The application of renewable energy in electric power system is growing rapidly due to enhanced public concerns for adverse environmental impacts and escalation in energy costs associated with the use of conventional energy sources, distribution generation (DG) is recognized as an encouraging and cost effective generation source both in large grid connected systems and small isolated applications. Power output from distribution generation is not readily controllable. High distribution generation penetration can lead to high-risk levels in power system reliability and stability. In order to maintain the system reliability and stability, this paper presents a probabilistic evaluation method that can incorporate the impacts on reliability of new energy utilization in electric power systems. Two procedures designated as equivalent simplifying method and the islanded reliability calculating method are proposed and discussed. In the equivalent simplifying method, the equivalent failure rate and failure during time for a given system at a specified reliability level is determined using system equivalent simplifying. In the islanded probability calculating method, the islanded probability at a load point for a given system containing distribution generation is calculated. The analysis results of example show that the probabilistic evaluation method is feasible for the operator to decide the appreciate capability and detailed location of possible distribution generation in electric power systems, and consequently a desired level of reliability is obtained.