Patent RU-2568422-C9 (RU)
Title: Method of determination of parameters of industrial frequency electric signal vector
Inventor: MAMAEV VIKTOR ALEKSANDROVICH
IPC: G01R29/10
Filed: 2014-09-15
Granted: 2016-02-27
Abstract: FIELD: electricity. 
     SUBSTANCE: method includes the use of the digital information and measuring device consisting of the nonlinear function generator (NFG) and the linear function generator (LFG). NFG has one input and two outputs, its input is hooked by the industrial frequency electric signal f c , and each of two NFG outputs supplies the information connected with values of the module and angle of rotation of the vector of electric signal with the industrial frequency f c . LFG has two inputs, each of which is connected only with the respective output of NFG. LFG has two outputs, and these outputs supply the information in the format necessary for the subsequent use, namely its first output supplies the information which is unambiguously connected with the parameter which unambiguously defines the vector module, and the other output supplies the information on the angle of rotation of this vector. NFG structure comprises several subblocks among which the first subblock has one output which supplies the first auxiliary sinusoidal industrial frequency signal with unit amplitude generated by it. And the argument of sine function is set through the sum of two variable summands, while the first summand is defined by the product 2πf c ·t, and the second summand is the variable phase angle θ added into the computing process. Besides, NFG includes the second, third, fourth and fifth subblocks. While the second subblock has one input and one output, and both its single input, and the second input of the third subblock are supplied by the analog electric sinusoidal signal a c (t) of the industrial frequency f c , while the second subblock defines such its integrated parameter as the effective value A which is connected unambiguously with A vector module. While the information on the value A is transmitted to the first input of LFG and the first input of the third subblock, while the third subblock performs the operation of division of the analog electric sinusoidal signal a c (t) supplied to its second input by the effective value of analog electric sinusoidal signal a c (t) supplied from the second subblock to the first input of the third subblock. The result of this division in the form of the second purely t-dependant auxiliary signal, from the output of the third subblock is supplied to the first input of the fourth subblock, and to the second input of the fourth subblock from the output of the first subblock the first sinusoidal auxiliary signal is supplied, and the fourth subblock performs multiplication of the signals supplied respectively to its first and second inputs. The result of multiplication in the form of the third auxiliary signal is supplied to the output of the fourth subblock, while the third auxiliary signal is the function of two parameters, namely time t and the variable phase angle θ added into the computing process. The third auxiliary signal is supplied to the input of the fifth subblock which performs the first t time integration within the period f c  pre-set by industrial frequency, and the functional dependence obtained after the first integration is processed by the operation of the second integration by the parameter of the variable angle θ added into the computing process and within the interval from 0 to 2π such value of the angle θ is determined at which the numerical value of the second integration is equal to √2 or in view of the accepted error is close to this value. The variable angle θ complying with this condition is taken as the angle of rotation ψ c  of A vector which is the vector image of the electric signal of industrial frequency f c , and the information on the angle of rotation ψ c  is supplied to the second output of NFG and the to the second input of LFG. 
     EFFECT: simplification of algorithm of obtaining of vector parameters. 
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