西门子SIMADYN D电调控制系统OPC功能浅析

简述了目前汽轮机组常见的OPC功能的实现方法,分析了电网中机组OPC功能设计和实现需要注意的问题,并介绍了OPC功能在SIMADYN D控制系统中的不同实现方法及其特点。

电调天线设备控制系统的设计与实现

针对提高网络维护和优化效率的需求,开发了电调天线设备控制系统,实现了对诸如RCU、TMA等电调天线设备的远程监测和控制。从系统拓扑结构、主从设备之间通信方式、软件体系结构、系统具体实现方法等方面讨论了电调天线设备控制系统的设计与实现。系统采用层次化的软件体系结构,具有较好的适应性和扩展性;准确完整地实现了AISG2.0,能够与任何符合AISG2.0协议的第三方电调天线设备兼容和互操作。

基于掩码推进的电调天线设备树形扫描算法

针对AISG协议要求和电调天线设备唯一标识符(UID)编码特点,提出基于掩码推进的电调天线设备(ALD)树型扫描算法,扫描过程中发生碰撞时通过掩码推进生成新的扫描分支。理论和仿真分析表明:1位掩码推进(二叉)树型扫描算法和2位掩码推进(四叉)树形扫描算法性能相似,而且性能接近最优。实际开发的电调天线控制系统采用2位掩码推进(四叉)树形扫描算法。实践证明,该算法具有较好的适用性,可以快速准确扫描识别不同厂家的各种ALD。

发电厂投入一次调频必要性分析

分析了目前内蒙古电网一些新投产机组和改造机组一次调频功能不投入的原因,并指出不投入一次调频功能对电网安全稳定运行带来的影响。

自适应二叉树电调天线设备扫描算法研究

首先根据AISG通信特点,提出基于二叉扫描树的ALD扫描算法,该算法通过引入冲突队列,对扫描过程中发生的冲突进行分解并生成新的扫描码。然后在分析二叉扫描树特点的基础上,提出自适应二叉树ALD扫描算法,该算法能够根据扫描过程中的一些先验结果跳过部分冲突节点,有效减少扫描过程中的冲突次数,提高扫描效率。实际开发的电调天线控制系统采用自适应二叉树扫描算法,证明该算法具有较好的适用性,可以快速准确地扫描、识别不同厂商的各种ALD设备。

Neural adaptive PSD decoupling controller and its application in three-phase electrode adjusting system of submerged arc furnace

Taking three-phase electrode adjusting system of submerged arc furnace as study object which has nonlinear, time-variant, multivariable and strong coupling features, a neural adaptive PSD(proportion, sum and differential) dispersive decoupling controller was developed by combining neural adaptive PSD algorithm with dispersive decoupling network. In this work, the production technology process and control difficulties of submerged arc furnace were simply introduced, the necessity of establishing a neural adaptive PSD dispersive decoupling controller was discussed, the design method and the implementation steps of the controller are expounded in detail, and the block diagram of the controlled system is presented. By comparison with experimental results of the conventional PID controller and the adaptive PSD controller, the decoupling ability, adaptive ability, self-learning ability and robustness of the neural adaptive PSD dispersive decoupling controller have been testified effectively. The controller is applicable to the three-phase electrode adjusting system of submerged arc furnace, and it will play an important role for achieving the power balance of three-phrase electrodes, saving energy and reducing consumption in the process of smelting.

Analysis of nonlinearities and effects in direct drive electro-hydraulic position servo system

The direct drive electro-hydraulic servo system is a new approach hydraulic system. It is much smaller and easier controlled than traditional systems and is a perfect energy saver. This paper will briefly introduce the popular nonlinearities in the electro-hydraulic system and analyse the effect of nonlinearities in direct drive electro-hydraulic position servo system by means of simulation research. Some valuable conclusions are given.

Predictive current control system of PMSM based on LADRC

For a permanent magnet synchronous motor(PMSM)model predictive current control(MPCC)system,when the speed loop adopts proportional-integral(PI)control,speed regulation is easily affected by motor parameters,resulting in the inability to balance the system robustness and dynamic performance.A PMSM optimal control strategy combining linear active disturbance rejection control(LADRC)and two-vector MPCC(TV-MPCC)is proposed.Firstly,a mathematical model of a PMSM is presented,and the PMSM TV-MPCC model is developed in the synchronous rotation coordinate system.Secondly,a first-order LADRC controller composed of a linear extended state observer and linear state error feedback is designed to reduce the complexity of parameter tuning while linearly simplifying the traditional active disturbance rejection control(ADRC)structure.Finally,the conventional PI speed regulator in the motor speed control system is replaced by the designed LADRC controller.The simulation results show that the speed control system using LADRC can effectively deal with the changes in motor parameters and has better robustness and dynamic performance than PI control and similar methods.The system has a fast motor speed response,small overshoot,strong anti-interference,and no steady-state error,and the total harmonic distortion is reduced.

Wide speed range for traction motor in braking force of electric braking control system

A vehicle stopping method using an electric brake until a traction motor is stopped is studied. At the moment of vehicle stop, electric brake is changed to control mode where torque is reduced at a low speed. Gradient is controlled by estimating the load torque of motor, thereby traction motor is not rotated after stop. In addition, coasting operation and brake test are performed from normal-opposite operation and start using a small-scale model comprising the inertial load equipment and the power converter. Further, traction motor is made to be equipped with a suspension torque. Pure electric braking that makes traction motor stop by an air brake at the time of stop is also implemented. Constant torque range and constant power range are expanded during braking so that braking force is secured with the electric brakes even in high speed region. Therefore, vehicle reduction effect can be expected by reducing parts related with an air brake which is not used frequently by using a pure electric brake in the M car in wide speed region. Further, maintenance of brake system can be reduced. Besides, ride comfort of passenger in the electric rail car, energy efficiency improvement, and noise reduction effect can be additionally expected. Further, an improved brake method that uses only an electric brake till motor stop is proposed by comparing those in the blending brake that uses an air brake while reducing brake torque at vehicle stop.

Wind Generator Stabilization with Doubly-Fed Asynchronous Machine

This paper investigates the function of doubly-fed asynchronous machine(DASM)with emphasis placed on its ability to the stabilization of the power system including wind generators.P(active power)and Q(reactive power)compensation from DASM can be regulated independently through secondary-excitation controlling.Simulation results by power system computer aided design(PSCAD)show that DASM can restore the wind-generator system to a normal operating condition rapidly even following severe transmission-line failures.Comparison studies have also been performed between wind turbine pitch control and proposed method.

A novel robust adaptive controller for EAF electrode regulator system based on approximate model method

The electrode regulator system is a complex system with many variables, strong coupling and strong nonlinearity, while conventional control methods such as proportional integral derivative （PID） can not meet the requirements. A robust adaptive neural network controller （RANNC） for electrode regulator system was proposed. Artificial neural networks were established to learn the system dynamics. The nonlinear control law was derived directly based on an input-output approximating method via the Taylor expansion, which avoids complex control development and intensive computation. The stability of the closed-loop system was established by the Lyapunov method. The current fluctuation relative percentage is less than ±8% and heating rate is up to 6.32 ℃/min when the proposed controller is used. The experiment results show that the proposed control scheme is better than inverse neural network controller （INNC） and PID controller （PIDC）.

Optimal design of coordination control strategy for distributed generation system

This paper presents a novel design procedure for optimizing the power distribution strategy in distributed generation system. A coordinating controller, responsible to distribute the total load power request among multiple DG units, is suggested based on the conception of hierarchical control structure in the dynamic system. The optimal control problem was formulated as a nonlinear optimization problem subject to set of constraints. The resulting problem was solved using the Kuhn-Tucker method. Computer simulation results demonstrate that the proposed method can provide better efficiency in terms of reducing total costs compared to existing methods. In addition, the proposed optimal load distribution strategy can be easily implemented in real-time thanks to the simplicity of closed-form solutions.

Achieving maximum power transfer of inductively coupled wireless power transfer system based on dynamic tuning control

As an emerging research field,inductively coupled wireless power transfer(ICWPT) technology has attracted wide spread attention recently.In this paper,the maximum power transfer performances of four basic topologies labeled as SS,SP,PS and PP are investigated.By modeling the equivalent circuits of these topologies in high frequency(HF),the primary resonance compensation capacitances for maximum power transfer capability are deduced.It is found that these capacitances fluctuate with load resistance change,which is disadvantageous to SP,PS and PP topologies and an obstacle to their practical applications as well.To solve this problem,a phase controlled inductor circuit is proposed.By adjusting the triggering angle,the real-time dynamic tuning control can be achieved to guarantee maximum power transfer.Finally,simulations and experiments show that the proposed method is of great effectiveness and reliability to solve the issue of resonance compensation capacitance fluctuation with load change and to guarantee the flexible applications of all topologies.

A new power coordination method for islanded micro-grid basing on multi-agent system

Multi-agent system (MAS) can provide flexible and intelligent control for micro-grid (MG). In this paper, a new power coordination method of MAS is presented for MG. New way for dispatching controllable generations (CGs) and direct cooperation between storages and CGs are designed. Real-time emulations of the coordination, including the usage of both CGs and storages, have been carried out in islanded situation basing on this method, and much higher performance than conventional method is found.