O. Sajdl

Experimental Smart Grid

The paper deals with activities towards a design of a methodology to stabilize already existing electrical grids and at the same time utilize the maximum of electrical energy from renewable electrical energy sources. The authors believe that the first step towards a methodology is to create a thorough model of the electrical grid with connecting most suitable existing renewable as well as classic electric energy sources. There is also described an idea of an experimental smart grid, but the main attention is given to the physical realization of a laboratory model of the smart grid. The authors described an electronic design and an idea of control strategy to enhance a functionality, stability and effectiveness of the grids with a significant share of the renewable energy sources.

Energy Sources for an Experimental Electrical Network: PV Panel and Micro-Hydroelectric Power Plants

Abstract The authors present energy sources for an Experimental Electrical Network (E.E.N). The main sources applied are photovoltaic and hydroelectric power plants. For the purposes of modelling the experimental network, the authors describe the measured values of the output power provided by the plants. The performance of the photovoltaic station was measured for the period of three weeks; as expected, the resulting value is strongly dependent on the weather. In the small hydroelectric station, we monitored the relation between the turbine output power and the water level in the weir. Moreover, we also produced a six-hour record of the performance of the station. Based on this characteristic, the relation between the water level and the output power was determined using approximation of the exponential function. The paper also describes the perspectives of remote sensing of the data acquired from a power plant and analyzes the possibilities of storing the data to an SQL server.

Virtual Automation Networks - one way from incompatibility

Abstract Paper deals with existing situation in industrial communication. Apart from proprietary serial communication systems exist many standardized fieldbuses. Due to increasing requirements on rapid data transfer and in hope of better transparency of communication in the overall plant control architecture, Ethernet has established as a well known and broadly used industrial communication technology. The paper shows one of possible methods for at least partial overcoming of the existing heterogeneity and incompatibility in large highly distributed control applications. The way is virtual automation networks and paper specify requirements and key features of the solution. The most important part of the paper deals with questions of the real - time features of virtual automation networks and the data security in heterogeneous communication environment.

Zigbee-Based Wireless Distance Measuring Sensor System

A cost effective ZigBee-based wireless parking sensor system is presented in this article. Ultrasonic transmitter and receiver are used for distance measurement. An evaluation, control and wireless data transfer are realized by one chip – Panasonic hybrid chip PAN4450 (8-bit microcontroller + IEEE 802.15.4 radio). System consists of four independent distance sensors and one central display and control unit.

Smart Sensors in Wireless Network System

The papers deals with a concept of a novel wireless smart sensor network system, which represents the system architecture formed by a set of the wireless smart pressure IEEE 1451 sensors connected via a Bluetooth connection and a network concentrator/controller based on (i) a PDA personal digital assistant or (ii) a GSM SmartPhone. A novel innovative design enables direct control of the whole system by those smart devices with Bluetooth connectivity. The special software applications were developed for IPAQ PDA 5450 and Nokia 3650 SmartPhone for monitoring, parameter setting and exploiting all embedded functions of the novel smart pressure sensors with Bluetooth wireless interface (slave function). Another SW application for standard PC enables to process data in MS Office formats. This wireless system virtual port enables to configure the sensor, to sense and to record data by remote reading and/or writing via a Bluetooth SPP supported port by a PC, a PDA or a SmartPhone equipped with a Bluetooth standard access module

Structure of the Smart Energo model control system

The paper describes two levels of control that are used for an efficient transfer of energy in a Smart Grid (a lower and higher level). This grid consists of several storage sites and resources. Each part of the model simulates various uses of resources or a storage. The lower level of control handlesa safety of the system and a fundamental moving of energy. The aim of control higher level is to use and store as many energy from sources as possible. It uses a weather forecast for a prediction of energy production. Control strategy is selected from obtained data, so storage sites have enough space for storing.

Parameter identification of PMSM

The following paper describes an identification of quadrature inductances of a permanent magnet synchronous motor. This identification is a frequency analysis base on an injection of a harmonic signal to control. This method utilizes knowledge of synchronous motor schema in d-q coordinates and it is based on mutual signals correlation. This method is primary an offline method. But in this paper it is used as an online method. The algorithm was tested on a real motor through a real time platform D-space.

Embedded System with Speech Recognition for Wireless Actuator Control

An embedded system with speech recognition algorithm for wireless actuator control is presented. Speech commands can control any connected actuator like lights, air condition, etc For wireless connectivity IEEE 802.15.4 radio (ZigBee lower layers) is used. It is maximally cost effective, low power, but fully functional and extendable solution.

Modeling of 10-bits, 40 MHz, low power pipelined ADC utilizing novel background calibration

The article presents new background calibration technique, which is utilized in new 10-bit low power switched-capacitor(SC) pipelined ADC. Since portable applications demand for low power consumption, it is one of the most important issues considered in the design. A modified operationalamplifier (op-amp) sharing technique - shared operational transconductance amplifier (OTA) was used to decrease the power usage as well as capacitor scaling approach. The problems caused by SC (i.e. clock feedthrough from digital part through the switches, capacitor mismatch etc.) are avoided using the fully differential circuitry in conjunction with novel background calibration. The special OTAs and comparators were designed for this purpose and to obtain large bandwidth. The power consumption of the OTAs was taken into account too. The finite OTA dc gain problem is solved in digitaldomain using background calibration. The capacitor mismatch and OTA offset are compensated in the same manner as mentioned above.