Algebraic systems with locally varying matrices for control in electrical energetics: A solution method

Deterministic relations are used to design a method and an algorithm for solving algebraic systems of equations with locally varying coefficient matrices encountered in operational control problems in electrical energetics.     

The band formula for A.N. Krylov’s problem

A new formula for solving the Krylov problem on the basis of band matrices is proposed. Properties of the obtained formula are studied for problems of analysis and synthesis of linear controlled systems.     

Touch Voltage and Electrical Safety when Maintaining Overhead Power Transmission Lines

Power Technology and Engineering - The problem of electrical safety involving the assessment of hazardous factors during repair of overhead transmission lines is considered. The conditions of...     

Unloading angular momentum for inertial actuators of a spacecraft in the pitch channel

The problem of gravitational unloading of the angular momentum of inertial actuators of a spacecraft in the pitch channel for circular and elliptic orbits is considered using the band theory of modal control. Control laws for gravitational unloading and stabilization of a given spacecraft position unambiguously determined by the object parameters and given coefficients of characteristic equation are obtained.     

Band formulas for calculating the numerator’s coefficients of the transfer function of a single-input system

Based on band matrices, a new formula for finding polynomial coefficients of the numerator of the transfer function for a linear single-input single-output system is derived. Its properties are studied for analyzing and synthesizing linear systems with many outputs, as a result of which a method is developed for the synthesis of the specified polynomial of zero dynamics (specified output) for a linear system with many outputs.     

Synthesis of stabilizing spacecraft control based on generalized Ackermann’s formula

Problem of modal synthesis of controllers and observers using the generalized Ackermann’s formula is solved for a spacecraft as a complex dynamic system with high interconnections. All possible controller matrices (the whole set of controllers) are obtained for solution of the problem of stabilization of orbital orientation of the spacecraft in inseparable channels of bank and yaw angles.     

Band Controllability and Observability Tests

New controllability and observability tests for linear stationary dynamic systems are derived in the form of special banded matrices. Band tests aid in determining the conditionality of rank controllability and observability tests.     

The switching life of short-circuit contact breakers in power systems

Integral distributions of the actual values of short-circuit currents in the 100–500 kV networks, obtained by processing oscillograms of the transients in electrical transmission lines, are presented. It is shown that in the majority of newly established modern gas-filled contact breakers with spring-loaded drive mechanisms the switching and mechanical lives will not be exhausted after their useful life. Hence, planned repairs of such contact breakers can be predicted starting from their actual state and not from the fixed inter-repair periods. * JSC “Otdelenie Dal'nikh Peredach,” Russia. ** Electric Main Line Network Center (MéS Tsentra), Russia. *** IVTs Mosénergo, Moscow, Russia. **** Moscow Power Institute – Technical University, Moscow, Russia. ***** JSC “énergoservisproekt,” Russia. Translated from élektricheskie Stantsii, No. 10, October 2008, pp. 59–62.     

Synthesis of linear postcompensators for signal processing of nonlinear systems of a special form

Application of liner postcompensation, namely, processing signals of a dynamic system beyond a closed loop containing this system, to a nonlinear system of a special form is considered; the form of the nonlinear system allows compensation of the nonlinearity via satisfaction of the solvability conditions. It is demonstrated that postcompensation is equivalent to the inclusion of the object in some feedback. The possibilities of transforming the dynamic properties of the object using postcompensation are determined by the form of the feedback whose effect is reproduced by the given post-compensator. A method for post-compensator synthesis, corresponding examples, and simulation results are presented.     

Solvability conditions of problem of synthesizing proportional-integral control of a linear MIMO system

The solvability conditions and just the solution of the problem of the regular and irregular proportional-integral (PI) control are found in accordance with the properties of invariant zeros of a multi-input multioutput (MIMO) system. It is proved that the problem of synthesizing the control of the MIMO system is solvable if and only if the pair of matrices (A, B) that describes a control plant is controllable and the matrix B_L^⊥AC_R^⊥ (where B_L^⊥ is the left zero divisor of the matrix B and C_R^⊥ is the right zero divisor of the output matrix C) has a complete row rank.