Evaluation criteria and the choice of the equipment for the systems of automatic control of independent power stations

02/02/2009
The article of V.A. Rodina - CEO in Neva Electric Ltd., PhD in Technological Sciences
The systems of the automatic (automated) control (SAU) for independent industrial and ship power stations (AEU), as well as other specialized SAU, have certain specifics of structure and functioning. For optimization of the choice of devices and the SAU AEU equipment it is necessary to define the main criteria of their quality. Defining, certainly, there is a cumulative criterion the price quality [1]. The unilateral approach in SAU assessment generally on a price indicator practiced by most of domestic customers is the gross blunder caused by "a children's disease" of formation of Post-Soviet economy. As medicine it would be possible to offer a reminder that "free cheese" happens, alas, only in the mousetrap. Doesn't raise doubts that at the present stage of development of technical means the similar analysis makes sense only concerning systems which cornerstone specialized microprocessor controllers of management (MPK) are. It is necessary to carry to key parameters of quality of MPK, first of all: reliability, universality, selectivity and ability to development, ergonomics and informational content, communicativeness and constructive compactness. Reliability of functioning is defined by simplicity micro and macroarchitecture of MPK, small number of active links and converters of food, minimization of contact and terminal connections, use of hi-tech accessories of elements and also the advanced technologies of designing, an algoritmirovaniye and programming allowing construction the redundantnykh of control systems (the systems of double reservation) firm to external mechanical and electromagnetic influences and also the influences connected with misuse or service. Characteristics of parameter of reliability define durability of MPK. The universality characterizes a possibility of application of MPK with a wide range of electrical power installations irrespective of their type and power and also a kind of information and executive channels. The selectivity is characterized by functional and structural flexibility of MPK, a possibility of adaptation to various algorithmic and physical parameters of an object. The ability to development or functional updating defines a possibility of improvement of the software (updating of versions ON) without essential change of a design of hardware throughout service life. The parameters of ergonomics and informational content defining, on the one hand, convenience in management and presentation in which basis criteria of simplicity and the minimum sufficiency are put, on the other hand - completeness of the displayed information allowing the operator to gain an exhaustive impression about installation work as in the static, and dynamic modes, permanently and retrospectively are of particular importance. Important indicators of informational content are existence in MPK of the registrar of the current events and also dynamics of their change, elements of self-diagnostics, functions of the emergency and precautionary alarm system and display of states and processes of the power station. MPK communicativeness decides by ability physical (interfaces) and information (protocols) adaptation in standard communication systems for data exchange on similar or other MPK and also on the systems of the top level (dispatching stations, remote controls, etc.). The constructive compactness is estimated by relative weight and dimensional indicators of MPK. Important indicator of quality of MPK is the so-called "functional weight" in the general structure of SAU defining relative functional employment in realization of control algorithms and protection of AEU. Increase in this indicator, with other things being equal, allows to reduce significantly cost and to increase reliability of the SAU equipment. The described criteria of quality have been the basis for the concept when developing the Symap® device by Stucke Elektronik GmbH [2]. Symap® (to read – Saymep) is the universal specialized microprocessor control unit and protection of common industrial and ship electrical power installations intended for use in low-voltage, the srednevoltnykh and high-voltage power supply systems of high extent of automation [3]. Creation of MPK Symap® is based on the principle of optional configuration: constructive (12 modifications), functional (the choice of optional software packages), at the choice of parameters of measuring signals and supply voltage, at the choice of number of discrete and analog inputs and outputs and communication interfaces. It allows to optimize the ordered devices at the price. The front Symap® panel is executed according to modern requirements to the person car interface (HMI). The big graphic display gives the chance to display a maximum of the current status, parametrical, emergency and precautionary, service, diagnostic and other information. Management and a parametrirovaniye by means of the minimum set of action and navigation buttons by the principle of the expanded menu simply allows to master and quickly the device in the self-training mode. System working configuration of the device according to the set control algorithm and protection can be made directly from the push-button field of the front panel and doesn't demand a programmator. In Symap® all main types of relay protection according to norms of MEK and ANSI, special functions of management and control of high-voltage cells and also functions of management, control and (or) protection diesel-generator, turbo-generator and the gazmotornykh of units, power two - and the trekhobmotochnykh of high-voltage transformers and powerful synchronous and asynchronous electric motors are realized. Symap® provides a full set of functions according to requirements of the highest extent of automation, as during the parallel operation of units of identical or different power, and during the parallel work with network. It is necessary to carry also high communicativeness and selectivity to advantages of the device. Communication RS232, RS422/485 interfaces (4 versions of protocols of Modbus), the Profibus DP interface in wire or fiber-optical execution, two independent Canbus interfaces and also the GPS channel are provided to the user at choice. The analysis of the modern European market of MPK for AEU with high extent of automation shows unconditional leadership of devices of the Symap® family in the class on a cumulative indicator the price quality that is confirmed by also high sales level as in Europe (including Russia), and in Asian, North American and Latin American regions. Sources and literature: 1. Rodin V. A. Questions of optimization of estimated factors when developing industrial control system//the Exposition of the Power engineering specialist. 2008. No. 5/E (63). P. 34 2. www.stuckegmbh.de 3. www.nevael.spb.ru