DIRECTIONS OF R&D ACTIVITY
1. Development of Theory for Energy Storage Structures based on Multilevel Converters and Storage Batteries
Project is devoted to scientific research concerning accumulation of electrical energy by means of power electronics devices and accumulator batteries with big capacity. Urgency of the problem is defined by possibility of realization of Smart grid conception. This conception supposes mandatory use of power electronics devices, particularly, as a part of accumulating system.
Taking into account the level of accumulated energy and parameters of existing electrical networks high energy efficiency is provided by using of high-voltage multilevel semiconductor converters of electrical energy.
Projected is directed to development of theoretical base for analysis and construction of power system “electrical grid – multilevel converter of electrical energy – accumulator battery”. The main attention is paid to sulfur-sodium accumulators with high power in order to provide stable functioning of the system under the irregular energy consumption and supply of responsible consumers.
Using of power accumulators and multilevel converters will allow creation of accumulating system with high power (1-50 MW) with the duration of recuperation about 5-7 hours.
For solving of the task special mathematical base using geometrical analogies, double Fourier series, spectral and wavelet transforms of the functions with finite argument in Galois field is developed. Vector control algorithms as for converter, and for whole accumulating system will be created.
Creation of new methodological approach and control algorithms allowing prolongation of life term of accumulator batteries, increasing of energy efficiency of accumulation, converting and transferring of electrical energy will be the main results of project deployment.
2. Principles of Efficient Monitoring and Partial Control of Physiological Variables using Spectral and Wavelet Transforms of Discrete Functions with Module Argument
Effective monitoring and control of biomedical variables that characterize physiological human state is especially urgent under the emergency conditions when the time of decision making about current situation and the fastest measures for the treatment and/or life-saving become the key factors.
Existing approaches for the solving of this task usually are not enough fast-acting or even become unable to work effectively in real time.
Using of new spectral and wavelet transforms for collecting, coding/decoding, processing, analysis, noise-protective transmitting of biotelemetrical information allows to increase immunity and speed of decision-making. Thus, it will allow to increase effectiveness of monitoring and control of physiological human state and early delivery of health-care. Such approach will increase significantly (in 10-15 times) the speed of biotelemetrical data processing in comparison with traditional analysis methods, sustainable transmitting under the noises and applying of knowledge and skills of medical experts. There are no analogues of such approach for the moment.
Generally, project implementation will create the background for early diagnostics of physiological state, improving of protection and life sustaining for the people in emergency states.
- Investigation of intellectual control of energy consumption in SmartGrid using LabView tools
Development of new generation of inverters with adjustable characteristics oriented for the implementation in SmartGrid with modern intellectual system for the monitoring technical parameters and environmental context data.
Intellectual control&monitoring system based on LabView software will perform the following functions:
– Visualizing the measured data in LabView (photovoltaic power, current and voltage of the inverter, the ambient temperature, temperature of PV modules, temperature of inverter elements);
– Calculation of integral parameters of grid energy (rms voltage, total harmonic distortion, power consumption, power factor);
– Calculation of control signals for the inverter on the basis of context and ontology data.
The monitoring system will simplify the configuration and adjustment of the power supply based on the voltage inverter, their operation and maintenance. Modern technology of printed circuit board producing and radio elements mounting will be used during the project deployment.
- Increasing of Intellectual Effectiveness of Electronics and Energy
Development of coordinated control of inverters with increased intellectual effectiveness in the system of distributed energy generation with PV cells. Control system of inverters connected to PV cells provide the functioning of one inverter in the regime of voltage source, and others – in the regime of current sources controlled by load voltage. In the case if the system of distributed generation includes other main generator that works in the regime of voltage source (e.g. diesel or wind generator) all inverters of PV cells work in current source regime. Such approach allows to provide parallel and coordinated work of significant amount of inverters without previous tuning due to specialized software and realization of cloud calculations using microprocessor unit of each inverter as the node of calculation-controlling network of the whole energy supply system.
Most effective use of electrical energy from PV generators is achieved by adjustment of external characteristics of the inverters to the tasks of external network according to outer factors and control influence. Energy efficiency of the system proposed is increased additionally at the expense of prediction of PV cell illumination levels. Work in the regime of maximum energy tracking is provided by using converting devices and special control algorithms for them.
Intellectualization is provided by self-synchronization of inverters’ control systems combined into common system that allows to increase intellectual efficiency.
Implementation of new methods of self-synchronization of electrotechnical devices joined in common system, mathematical apparatus of spectral and wavelet transforms of the functions with modular arguments, methods of spectrum spreading, concurrent filters for coding and noise-protected data transmission results to maximum effectiveness for energy supply systems, Micro Grid and Smart Grid with renewable sources.
- Filter-compensative converter in the system of guaranteed energy supply with accumulator
Today quite a significant problem in energetics and power electronics is networks electricity quality deterioration that is displayed in power factor decreasing and increasing of higher harmonics in consumption current that results in mains voltage distortion, which is unacceptable if loads requiring high power quality are connected to the same network. The above listed negative effects lead to energy losses in network and equipment which in turn is one of the reasons for auxiliary heating and resource reducing of devices that require high quality power. Another problem is ensuring uninterruptible equipment power supply. The consequences of intermittent power supply can be: data loss, devices resource reducing or even their disabling. Given the above listed issues the use of hybrid devices is expedient – reactive power compensators that can operate as uninterruptible power supply (UPS). With THD of tens percent the most appropriate is to use active compensators as active power line conditioners (APLC). When designing the reactive power compensator control system based on microprocessors it is important to create an effective operation algorithm. The main problem in control task of such a device is the compensator operating modes constant change, which is described by complex and cumbersome expressions of energy processes. This leads to the fact that the microprocessor has to perform a large number of transactions, which limits the entire control system performance.
For battery efficient use it is necessary to ensure charge control, self-discharge current compensation and connection number minimization that prolongs its operation. One of the variants of such battery use as a part of UPS based on APLC is its charge with direct current using PWM buck converter.
Based on the method of the current and voltage mean values as well as taking into account the energy balance the calculation algorithm of basic parameters and control laws of active power line conditioner with direct current battery charge should be developed to determine the interrelation between the device operating intervals, storage elements parameters, sinusoidal current amplitude and laws of pulse duty factors variation at corresponding intervals.
- Converters operating modes control in autonomous power supply systems
The problem of power consumption increase in autonomous power supply system with renewable sources provided constant joint operation of solar panel, wind generator, diesel generator and storage battery is urgent in terms of power efficiency. The solution to this problem can be made through power utilization factor more accurate calculation. To ensure the best power use in Smart Grid and more accurate calculation of the power utilization factor it is necessary to consider the equivalent sources external characteristics nonlinearity. In order to improve the energy efficiency of power supply system the diesel generator must have the external characteristic of the current source controlled according to the ratios of solar panel and battery current and the required level of load voltage.
When autonomous power supply system is operating with dissimilar sources the fullest power use will be provided taking into account equivalent power sources external characteristics nonlinearities at certain ratios of internal resistances, which allows to specify the power utilization factor calculation, closer to real, correct converters control signals, which leads to the level of power taken from sources real increase. The converters control system in autonomous power supply system produces control signals considering the changes of wind flow parameters, the value of solar radiation and therefore the sources equivalent resistance in relevant equivalent schemes that determines the position of the operating point on the external characteristic and source operation mode.
During the wind generators operation the level of energy transferred to the load and the storage battery will be maximum with condition that compensator forms the active character of the load.
In wind generators dynamical operation mode when changing the blades pitch angle and gondolas yaw angle and considering linear dependence of wind generators internal resistance on time, formation of the compensators current according to the equation allows to increase the energy level that can be taken from the wind flow no less than 2,2 %.
- Micropower electric converters based on thread ZnO nanocrystals
Nanogenerators of electric energy is one of the promising areas of micropower supply systems that can be used for power generation in life support systems, power mobile and medical devices, devices for collecting and processing information. The nanogenerator output voltage is unstable and change in a wide range. Due to the low (1.5 V) and unstable output voltage at the output must install electricity converters with low voltage drop and power in range from microwatts to several watts.
Electric power conversion allows reduce in several times energy loss and increases the efficiency. Reducing the amount of energy loss is achieved by special converter circuit, which will increase the service life of the power supply compared to systems based on chemical power sources several times.
Nanogenerator consists of an array of whisker nanocrystals, usually with zinc oxide or other materials that are both semiconductors and piezoelectric. The energy of deformation filamentary nanocrystals transform into electrical form. One of the conversion method deals with special electrode. The frequency of strains can be in a wide range from milihertz to tens of kilohertz. During electrode vibration, the deformation of nanofibers generates electrical energy, which appears on electrodes. The nanogenerator voltage amplitude is in the range of tens of millivolts to several volts. Output capacitor accumulates electrical energy and leads to significant volatility parameters of the output voltage.
The project solves an important scientific and applied problem of transformation and stabilization of parameters of electricity using semiconductor micropower converters. To construct the converter used high efficiency devices, which minimizes losses in transformers and provide the necessary parameters of load voltage.
- Monitoring of physiological parameters of human state based on image data
Project is devoted to creation of new scientific and practical basics for construction of modern high-effective system to monitor and control physiological variables using new mathematical methods of image processing.
Project assumes elaboration of:
-principles and means of applying of new discrete spectral and wavelet transforms of the functions with modular argument for processing, monitoring and control of biotelemetric parameters,
-theoretical basics of modern effective system for common monitoring and control of human state using data from biomedical sensors,
-creation of experimental samples of monitoring devices.
Resulting effect of the project includes joint publication of scientific papers, participation in international scientific and technical conferences, creation of algorithms, software and experimental samples.
Project stages :
- Develop a spectral-imaging device and acquire images reflecting human reactions to external stimuli.
- Identify and extract physiological parameters by using spectral and/or wavelet transforms.
- Embed the device in a fingerprint sensor or a scale and conduct fileld studies for daily-health monitoring.
For this particular project, strength in mathematics is a big plus especially in digital image processing techniques.
- Image compression
The image compression technique has been widely used to transmit or to store an image to save the transmission time or the storage space of the image. Among various compression techniques, transform coding is a favorite one. A new image compression approach that uses wavelet transform in oriented base (OBT) was developed. OBT using gives low computational cost and provides high rate-distortion performance.
- Noise-resistant communication via power lines for intellectual distant control for manufacturing, transport and household use
The data-communication remote-control system based on power-line signaling and spread spectrum modulation ensures the increased noise immunity and processing speed of signals. Mathematical methods of discrete spectral transform at oriented basis is used to increase the calculation speed and noise-protection.
- Distributed synchronization of separate nodes of the wireless network
New method of high assurance and survivability communication systems which ensures low probability of detection and interception is offered. Distributed synchronization of transceivers of separate network nodes based on principles of synchronization of finite state machines (finite-memory automatons with expedient behaviour) provides survivable, assured communication at a strategic and tactical level. Application of the transformation at oriented basis in communication systems with spread spectrum (DSSS, FHSS, CDMA) allows to increase number of channels in multichannel systems with code division in and to increase throughput of the communication channel, in comparison with previously used transformations at an equal frequency band.
- Intellectual systems of energy saving for local objects and private houses with renewable and alternative sources
Development of algorithms and systems of energy-efficient control for electrotechnical complex of local object with alternative sources on the base of new principles of intellectual control. Saving of energy resources and cost are achieved by taking into account economical effectiveness and cost criteria of optimal work of electrical devices.
Main goal of the project is development and investigation of new principles, algorithms and systems providing energy efficient control of power supply system of local object with renewable and alternative sources.
Achievement of project aim is based on combined centralized and decentralized strategy with hierarchic distribution of electrotechnical devices, minimization of user’s cost, new mathematical methods of spectral and wavelet transforms of discrete functions with m-ary argument, theory of collective behavior of automatic devices, construction of electrical-cost models of electrotechnical devices.
Task sharing includes analysis and control of electrotechnical systems and complexes, renewable energy sources, development of microprocessor systems and algorithms to control energy consumption, using of economical theory to realize functioning of electrical equipment by common criteria of cost minimization.
- Development of active filters with dynamic compensation of reactive power for AC networks (розробка технології динамічної компенсації реактивної потужності мережі змінного струму)
One of the ways to reduce the flow of transported energy without expanding the infrastructure (construction of new power plants and additional power lines) is to install reactive power compensators and active filters, which reduces power installed capacity by 30%. However, the existing principles of compensating equipment operation allow reactive power compensation only in the steady state, while in transient modes reactive power compensation is not provided. The project aims to achieve additional effect of energy efficiency and cost saving for electrical equipment operation.
- Emotions detection using speech
The use of speech to detect emotion has several advantages in Automatic Speech Recognition systems. Speech is the easiest way that a user can express his intentions and wishes trough. It would not need any additional transmission medium because telephone can be used. Speech is highly efficient due to the fact it is the most natural way of communication and is also easy to express. A research work in this area is performed on our chair with support of group of psychologists. The main idea is to create software that can be helpful for psychologists in their usual practice, and also to create a separate module that can be easily used in ASR systems.
- University microsatellite
University microsatellite is one of our big projects, which collaborates scientific brainpower and students of the many departments. The satellite will allow us to obtain experimental results in near-earth orbit. Thus, we conduct research work in next areas:
- Effective orientation approach development based on Sun recognition on stellar sky image.
- Precision stabilization system implementation based on terrestrial magnetic field.
- Low energy consumption algorithm for image coding on embedded platforms.
Adaptive high efficiency power system that works with different energy sources (solar, Li-Pol/ Li-Ion batteries).
- Multi-level voltage inverters for alternative energy source in Smart Grids
Energy-efficient and resource-saving control of working regimes of industrial equipment, integration of alternative energy sources (i.e. PV cells, wind generators) in modern Smart Grids. Experimental investigation and creation of practical recommendation for multi-level autonomous inverters with minimum number of switches and assigned waveform of output voltage (current) close to sine wave at assigned power factor. Creation of the methods to provide assigned waveform and quality of the voltage (current), non-symmetry factor. Implementation of new mathematical approaches to control multi-level inverters, simplification of the structure of control system and power circuit, simplification of the algorithms, increasing of fast-action, cost decreasing and quality improving of electrical energy in Smart Grids with alternative sources.
- Development of the converters for nuclear magnetic resonance
- Research in the field of the semiconductor converters for microwelding