发电/电动机下部组合轴承的自循环油系统

介绍了发电/电动机下部组合轴承的自循环油系统的功能及其结构组成的状况,该系统具有节能和可靠性高的特点。在此基础上,对采用该系统的浙江桐柏抽水蓄能电站的运行情况和运行数据进行了分析,通过运行数据的的分析和比较,得出了整个油循环系统运行运行状况良好的结论。

抽水蓄能发电/电动机转子不同结构的对比分析

转子是高速电机直接传递载荷的部件,其结构稳定性影响机组的安全运行。不同于常规水轮发电机,抽水蓄能电机需在发电工况和电动工况间频繁切换,从而导致转子因频繁变化的转向和转速更易出现破坏。目前,由于国内电机设计缺少对比数据,对转子应采取何种结构尚无定论。针对南方电网抽水蓄能电站T尾部和鸽尾部两种结构的转子,选取相同的实际运行条件对比分析了各自结构的温升及其导致的应力,并对比了离心力导致的应力分布情况。在此基础上,通过对比结构上的叠加应力评估了不同转子结构的运行能力。结果表明:鸽尾部转子的应力分布优于T尾部转子,从而具有更高的稳定性。但鸽尾部转子温升情况更恶劣,实际运行应重点监测温度变化。

抽水蓄能发电机定子槽楔松动原因分析及处理

详细介绍了黑麋峰抽水蓄能电厂3号、4号发电电动机定子槽楔松动情况,深入分析了可逆式电动/发电机槽楔松动原因,针对定子端部槽楔固定方式、方法进行技术改进,为大容量水力发电机定子槽楔松动处理提供参考。

南阳回龙抽水蓄能电站机组继电保护设计

回龙电站是我省首座抽水蓄能电站,电站建成后以担负南阳地区电网调峰填谷为主要目标,工况变换复杂、频繁。机组日平均起停8次(开、停一循环为1次),工况变换方式为静止发电、静止抽水、发电抽水,运行工况和控制内容远比常规水电站的静止发电单一工况复杂。作为机组故障情况下的预防和保护措施,必须配备技术先进和可靠性高的继电保护系统。文章介绍了回龙电站发电/电动机—变压器组继电保护的设计原则、配置方案及抽水蓄能机组保护的设计特点。

混合动力液压挖掘机的特点及应用分析

分析了混合动力液压挖掘机不同的结构形式、工作原理、技术特点及应用领域;提出了混合动力液压挖掘机存在的研究难点;并展望其应用前景。

一种混联式混合动力轿车动力源功率的优化计算

混合动力电动汽车是当今解决汽车节能与排污问题的有效途径。本文提出一种新的混联式驱动系统,并对其动力源的功率进行优化计算分析。结果表明,在保证汽车原有动力性的前提下,采用此结构提高了汽车的燃油经济性。

一种混合动力概念车驱动系统设计

为研究开发更先进的混合动力汽车驱动系统,分析了现行的起动机/发电机/电动机一体化混合动力汽车(ISG-HEV)和混联式混合动力汽车(PSHEV)驱动系统,指出了其各自不足之处;去掉传统变速箱和复杂的动力耦合装置,结合电子差速控制系统,设计了一种无级变速新型PSHEV驱动系统,并分析了该驱动系统工作过程、控制策略及能量流向;最后,分析论证了该系统的可行性。研究结果表明,该系统的结构布局和驱动效率都优于现行混合动力系统。

Study on Electromagnetic Force and Vibration of Turbogenerator End Windings under Impact Load(Ⅰ): Analysis of Electromagnetic Force of End Windings under Impact Load

In this paper, the boundary value problem (BVP) of 3 D transient eddy current field in the end region in the case that the generator is affected by impact load is specified. Besides, ways to implement discrete methods in both time domain and space domain during the solution of the problem are investigated. The Crank Nicolson scheme is utilized to attain the iterative format of time differential, after taking factors that can ensure both computation precision and stability into consideration. In this paper, the magnetic distribution in the end region of a turbogenerator in the case that the generator is affected by impact load is specified. As a result, it provides foundation for further study of electromagnetic force and electromagnetic vibration in the end region of the turbogenerator.

Study on Electromagnetic Force and Vibration of Turbogenerator End Windings under Impact Load(Ⅱ): Analysis of Vibration of End Windings under Impact Load

On the basis of the study of transient eddy current field in the end region of turbogenerator and electromagnetic force of end region winding, this paper analyzes the electromagnetic vibration of the turbogenerator roundly. A 320 MW turbogenerator is taken as an example to specify the electromagnetic force of end region winding and therefore the vibration in the case that the generator is affected by impact load. Some conclusions are drawn on the basis of the specification. Vibration of windings under imaginary faults is simulated, so that the vibration law of the end winding of turbogenerator can be studied further. On the basis of this, the countermeasure against winding vibration can be advanced.

Variable damping forces caused by electromagnetic energy harvesting with an adjustable load

A novel variable damper using an adjustable energy harvesting structure is proposed for semi-active vibration systems. The fluid flowing in a hydraulic cylinder is employed to drive an electromagnetic generator for harvesting vibration energy, which on the other hand, leads to a damping effect of the hydraulic damper. To make the damping force variable, an adjustable resistor is adopted to tune the capability of energy harvesting. The present approach is validated by both theoretical analysis and experimental evaluation. When connected with different resistance loads, the prototype damper has different equivalent damping coefficients ranging from 3. 987 × 104 to 2. 488 × 105 N· s/m. The results show that the damping force of the damper is variable in response to the adjustable load for the vibration energy harvesting.

催化装置烟气轮机动力回收

对锦州石油六厂烟气能量回收工作进行了详细的介绍,比较了三机机组与四机机组的优缺点,并就烟机机组中电机形式的选择进行了分析,最后对电机的安装、起动及并网、继电保护等技术问题进行了阐述。关键词三机机组四机机组发电机/电动机1引言我国的催化裂化烟气动力回收工作始于20世纪70年代。自1978年11月石油二厂第一台自行设计、制造的烟机机组投产以来,发展比较快,截止目前为止,建成或正在安装的机组已有30多套,其中20多套由国内自行设计制造。锦州石油六厂烟气能量回收部分原设计为四机机组,即烟—主风机—汽轮机—电动机—发电机,如图1所示。但由于种种客观原因,后来采用了三机机组设计,即烟机—主风机—电动机/发电机。如图2所示。三机机组和四机机组的优缺点比较见表1。就机组来看,四机机组是一种理想的高效机组,为了不影响生产仍配备了备用主风机机组。但许多厂为了更加可靠,减少设备的事故发生率,还在采用三机机组。三机机组起动时。

Torque Distribution Strategy for Integrated Starter/ Generator Hybrid Bus Implemented by Fuzzy Algorithm

A torque distribution strategy was designed by using fuzzy logic to realize the optimal control. The vehicle load zones were dynamically divided into several zones by several torque lines to indicate the drivers demand and the high or low efficient operating areas of the diesel engine. The fuzzy logic controller with trapezoid membership function and Mamdani rule reference mechanism was utilized. There are over 100 rules used in this fuzzy-based torque distribution strategy which are sorted into four rule-bases. The fuel economy and acceleration tests were designed to test and validate the integrated starter/generator (ISG) bus perfor-mance using fuzzy-based torque distribution strategy. The fuel economy is improved 7.7% compared with the rule-based strategy. Finally the road test results reveal that there is about 15% improvement of fuel economy. And the 0-50 km/h acceleration time is 9.5% shorter than the original bus.

Combustion simulation and key parameter optimization for opposite axial piston engine in small-scale

As potential alternative power sources used in portable electric generators, opposite axial piston engines in small-scale were investigated to show their advantages in power density. A novel cylinder charge system was introduced, based on which a quasi-dimension model and a CFD(computational fluid dynamics) model were established. Comparison of those two models was carried out to validate the quasi-dimension model. Furthermore, optimal diameter of charge cylinder and speed were determined after evaluating the quasi-dimension model based on different parameters. High agreement between the quasi-dimension model and the CFD model validates the quasi-dimension model. Further studies show that the power of engine increases with the diameter of charge cylinder. However, a too big charge cylinder lowers the fuel efficiency instead. Taking economic influence into consideration the charge cylinder should be 1.4 times power cylinder, which could ensure the power density, volumetric efficiency and fuel economic at the same time. Axial piston engine running at 1.0×104 r/min could achieve a better overall performance. The maximal power of engine with optimal parameters is 0.82 k W, which fits the power need of the portable electric generators completely.

Design of Robust Controller and Force Observer for PM Linear Synchronous Motors

The advantages of permanent magnet linear synchronous motors （PMLSM） include high speed and good motion precision compared with rotary motors. However, PMLSM are sensitive to uncertainties such as the parameter perturbations and end effect etc. A new nonlinear robust scheme of PMLSM is proposed to overcome this trouble. First, a quasi-linearized and deeoupled model with uncertainties is derived from the mathematical model of PMLSM by using the conception of feedback linearization. Then a fixed-boundary-layer sliding mode controller using the m sat function is designed to guarantee the robustness. Design of a force observer is given to estimate the load force unknown in the new model. Finally, the validity of the proposed strategy compared with the conventional PID control scheme is proved by the DSpobased experimental results.

Motion Performance and Mooring System of a Floating Offshore Wind Turbine

The development of offshore wind farms was originally carried out in shallow water areas with fixed （seabed mounted） structures. However, countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas. The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform. This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine （FOWT） system. The wind turbine was modeled as a wind block with a certain thrust coefficient, and the hydrodynamics and mooting system dynamics of the platform were calculated by SESAM soRware. The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined. The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.

Dynamic Simulation of Novel Small Wind Turbine Generation System with SynRG

This paper describes a small wind turbine generation system with SynRG （synchronous reluctance generator）. SynRGs are robust and inexpensive. In addition, SynRG has no cogging torque. Hence, wind turbine generation system with SynRG can achieve smooth start at low wind velocity. The rotor design of proposed SynRG is multi flux barrier type. With FEA （finite element analysis） software, the characteristics of SynRG are brought out, and the performance of wind turbine generation system with SynRG including copper loss and iron loss is simulated by FEA coupled with the motion equation of the wind turbine generation system under the maximum power point tracking control. In this paper, the constant wind test and the quasi-natural wind test are conducted. In conclusion, the results of these simulations indicate that the wind turbine generation system with SynRG has good performance, especially in starting phenomena.

Okutataragi抽水蓄能电站机组由不可调速到可调速的升级改造

在日本，由于上网电价补贴政策（FIT）的引导，太阳能及风力发电量已显著增加，随之而来的巨大输出变动导致了诸如频率波动及大的电力剩余等一些问题。这些问题的解决方案之一便是大容量电能储存系统，并且已经证明可调速抽水蓄能系统就是有效的解决方案。建设新的抽水蓄能电站需要很长的时间来处理环境问题，并且从经济角度出发，在日本几乎没有多余的空间来建设它们。既然建设新抽水蓄能电站作为解决方案尚不可行，那么对于即将达到寿命终点的老式固定转速机组进行升级改造将是最经济的。本文将介绍的这个项目是将日本最大容量抽水蓄能电站的不可调速机组升级为可调速机组，且升级过程中没有伴随现有设备和厂房的大规模重建工程。在升级过程中面临着许多挑战，如降低重量以便重新使用起重机，限制尺寸以便重新使用发电／电动机基座，并且确保飞轮效应（GD2），但我们通过使用一些技术，包括有限元法对机械及电磁应力进行分析，解决了这些问题。

Magnetically levitated/piezoelectric/triboelectric hybrid generator as a power supply for the temperature sensor

The combination of new intelligent materials and structure technology is becoming an effective way in energy havesting and self-powered sensing. In this work, we demonstrate a magnetically levitated/piezoelectric/triboelectric hybrid generator, which does not use complex structure and has high steady output performance. It includes three parts: magnetically levitated generator(MLG), piezoelectric generator(PNG), triboelectric nanogenerator(TENG). The peak power of each is 135 μW, 22 mW and3.6 mW, which are obtained at 1 MΩ, 10 kΩ and 1 kΩ, respectively. The hybrid generator can completely light up light-emitting diodes(LEDs) under the vibration frequency of 20 Hz and the vibration amplitude of 10 mm. It also can charge a 470 μF capacitor.On this basis, we have integrated the hybrid generaor as a power supply into a self-powered tempreature sensing system. The combination of three generators can not only broaden the operating range, but also increase the operating length and sensitivity.This work will extend the application of self-powered sensor in automatic production line and promote the development of industrial control technology.

Hybrid electromagnetic-triboelectric nanogenerator for harvesting vibration energy

We report a hybrid nanogenerator that includes a triboelectric nanogenerator （TENG） and an electromagnetic generator （EMG） for scavenging mechanical energy. This nanogenerator operates in a hybrid mode using both the triboelectric and electromagnetic induction effects. Under a vibration frequency of 14 Hz, the fabricated TENG can deliver an open-circuit voltage of about 84 V, a short-circuit current of 43 μA, and a maximum power of 1.2 mW （the corresponding power per unit mass and volume are 1.82 mW/g and 3.4 W/m^3, respectively） under a loading resistance of 2 MΩ, whereas the fabricated EMG can produce an opencircuit voltage of about 9.9 V, a short-circuit current of 7 mA, and a maximum power of 17.4 mW （the corresponding power per unit mass and volume are 0.53 mW/g and 3.7 W/m^3, respectively） under a loading resistance of 2 kΩ. Impedance matching between the TENG and EMG can be achieved using a transformer to decrease the impedance of the TENG. Moreover, the energy produced by the hybrid nanogenerator can be stored in a home-made Li-ion battery. This research represents important progress toward practical applications of vibration energy generation for realizing self-charging power cells.

Transient stability probability of a power system incorporating a wind farm

An analytical approach for probabilistic evaluation of transient stability of a power system incorporating a wind farm is presented in this study. Based on the fact that the boundary of practical dynamic security region(PDSR) of a power system with double fed induction generators(DFIG) can be approximated by one or few hyper-planes in nodal power injection space, transient stability criterion for given configurations of pre-fault, fault-on and post-fault of a power system is to be expressed by certain expressions of linear combination of nodal injection vector and the transient stability probability(TSP) is further obtained with a much more simplified expression than the complex integral. Furthermore, considering uncertainties of nodal injection power including wind power and load, TSP is calculated analytically by Cornish-Fisher expansion, which can provide reliable evaluation results with high accuracy and much less computing time compared with Monte Carlo simulation. TSP and its visualization can further help operators and planners be aware of the degree of stability or instability and find critical components to monitor and reinforce. Test results on the New England 10-generators and 39-buses power system show the method's effectiveness and significance for probabilistic security assessment.