SU1107239A2 - D.c. drive with minimization of motor losses - Google Patents

Abstract

DC ELECTRIC DRIVE WITH MINIMIZATION LOSS IN ENGINE by author. St. No. 758447, characterized in that, in order to reduce the total losses in the electric drive by controlling with a more precise definition of the minimum loss function taking into account the limitations, a calculator, two keys, a motor excitation flow sensor and an engine resistance torque sensor are entered into it, with the sensor outputs speeds, core current, excitation current, voltage on the engine bark, excitation flow and moment of resistance are connected to the inputs of the discrete calculator, the first two outputs of which are connected to two inputs of the first a key connected by a third input to the output of a two-input integration unit and an output to an input of a variable intensity change setting of the drive, and two second outputs of a digital calculator are connected to two inputs of a second key connected by a third input to the output of a three-input integration unit and an output to the regulator input excitement.

Description

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The invention relates to electrical engineering, in particular, to the field of a controlled direct current electric drive, controlled by the core circuit and driving a direct current motor. According to the main author. St. No. 758447 is known for direct current drive with minimization of losses in a motor, which contains the sensor for the NIN excitation current and voltage on the core, serially connected speed sensor, functional transducer and multiplication unit connected to the second input of the current sensor core, excitation regulator, to the output of the excitation controller is connected, the termination unit with three inputs, which are connected respectively with the output of the multiplication unit, the output of the voltage sensor on the cortex and the output of the sensor of the current current, and also A variable speed drive variable and a serially connected nonlinear unit and an integration unit with two inputs with output signal limitation, the input of the nonlinear unit connected to the speed sensor, the second input of the integration unit - c. The current sensor core and the output of the two-input integration unit is connected to the regulating input of the intensity setting knob. In this electric drive, by maintaining an optimal ratio between the crank circuit in the core circuit and the excitation flow, energy losses in the established regimes in the transient processes are minimized, i.e. the minimum loss in the engine: .QMK4% | (/, R,) 0, (I where UO is the angular velocity; 1- is the current in the crank circuit of the motor. R; is the internal resistance of the core circuit; K is the design factor of A; F is the motor excitation flow l; G (u)) is a variable coefficient characterizing the dependence of losses in steel on the speed of 9 L (B {k1K -f is the loss in steel of the engine; 1c is the engine excitation current; R is the resistance of the excitation winding ; DR, 4-dR 4.j2p dr /, I And A from B to the total losses in the engine; (w) - mechanical losses; MQ - the moment of static resistance on the motor shaft, satisfying conditions (1) and (2) provides achieving a minimum of functional quality:. Г РТ f М 3; ф :: Ж- Г (V 71 С J UJ.W. with joint regulation of the core current and the motor excitation flow and thereby ensures a minimum of the energy of losses that are lost in the engine during the process, without taking into account the restrictions imposed on the coordinates of the drive. When using formulas (1) and (2), we get the absolute minimum of the function F (3r, Φ, (l)). As n {) avilo, the absolute minimum point lies outside the permissible region of phase coordinates . The choice as the minimum point of the point of intersection of any restriction (e.g., the current of the core) with the curve corresponding to equation (1) leads to errors and the larger the further the absolute minimum point is from the limit. The aim of the invention is to reduce the total losses in the electric drive by controlling with a more precise definition of the minimum loss function, taking into account the limitations. The goal is achieved by introducing a discrete calculator, two keys, a motor excitation flow sensor and a motor resistance torque sensor, the outputs of the speed sensors, current cor, excitation current, motor core voltage, excitation flow and resistance torque being introduced to the discrete inputs the computer, the first two outputs of which are connected to the two inputs of the first key connected by the third input to the output of the two-way integration unit and the output to the input of the adjustable variable input unit ensivnosti varying the drive speed, and two second output digital calculator connected to two inputs of the second switch, the third input coupled with the output of integrating unit trehvhodovogo and output to the input of regulator drive torus. FIG. 1 is given the structural scheme of the proposed electric drive; in fig. 2 is the relationship between the core current and the excitation flow, where A is the absolute minimum point. The electric drive contains a drive current sensor 1 and a voltage sensor 2 on the crust, a speed sensor 3 connected in series, a functional converter 4 and a multiplication unit 5 connected to a current sensor 6 of a cor. To the output of the excitation controller 7, an integration unit 8 is connected to three inputs, which are connected respectively to the output of the multiplication unit 5, the output of the voltage sensor 2 on the crust and the output of the sensor 1 to the excitation current. A variable rate change setting unit 9 with water is connected with a series-connected nonlinear unit 10 and a two-input integration unit 11 with limited output signal. The input of the nonlinear unit 10 is connected to the speed sensor 3, the second input of the integration unit 11 is connected to the sensor 6 for the current core, and the output of the integration unit 11 is connected to the regulating input of the setting device 9. The electric drive also contains a discrete calculator 12, keys 13 and 14, a sensor 15 excitation flow and 16-point motor resistance sensor. . . The outputs of speed sensor 3, current cor 6 sensor, excitation current sensor 1, crust voltage sensor 2, excitation flow sensor 15 and resistor torque sensor 16 are connected to inputs of discrete calculator 12, two first outputs of which are connected to two switches 13 connected by the third input to the output of the integration block 11, the output .- to the input of the setting device 9, and two second outputs of the discrete calculator 12 are connected to two inputs of the key 14 connected by the third input to the output of the integration block 8 and the output of the regulator 7 wake up. In this electric drive, when the current of the core Jj is the maximum permissible according to the commutation conditions of the engine, the control is formed at the current of the excitation core current is calculated according to the conditions for providing the dimma function of the RRF, and () F-MS aF ( ..Pz ... Xnf Nf) (FLNL. N). The electric drive works as follows. The coordinates of the electric drive are entered into the discrete calculator 12. From speed sensor 13, core current sensor 6, core voltage sensor 2, excitation current sensor 1, flow sensor 15 excitation and torque sensor 16. Next, the discrete calculator 12 calculates the optimal values of the current i ;; and the engine flux flux by the formula (1), Then the discrete calculator 12 compares E with the maximum allowable current Jff. If D.J and the voltage on the bark c and the optimal value of the excitation flow} is calculated by the formula (4), where the magnetization curve is substituted by the signal from the output of the discrete calculator 12, the keys 13 and 14 are switched so that the analog part of the system is turned off and control in this mode is performed by the formula ( 4) If the voltage on the engine bark is greater than or equal to the maximum allowable DC (the keys 13 and 14 remain in the same state, and the control parameters are calculated by the discrete calculator 12 by the formulas:. , r, jminF (3, (: j,)); (g; 1: If 3 O, then keys 13 and 14 are switched by the signal of discrete calculator 12 in such a way that the analog part of the control system containing the nonlinear unit 10, the functional converter 4, multiplication unit 5 is connected to the setpoint adjuster 7. and integration blocks 8 and 11. In this case, the control is formed according to the law (1) ensuring the optimal process for minimizing the energy loss in the engine. Thus, the drive efficiency is optimal for energy losses m of restrictions imposed on the coordinates of the electric drive, which contributes to further reducing the loss of electricity

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Claims (1)

DC ELECTRIC DRIVE WITH MINIMIZATION OF LOSSES IN THE ENGINE by ed. St. No. 758447, characterized in that, in order to reduce the total losses in the drive due to control with a more accurate determination of the minimum of the loss function taking into account the restrictions, it introduced a discrete calculator, two keys, a sensor for the excitation flux of the motor and a torque sensor of the motor, the outputs of the sensors of speed, armature current, excitation current, voltage at the motor armature, excitation flux and resistance moment are connected to the inputs of a discrete computer, the first two outputs of which are connected with the two inputs of the first a key connected to the third input with the output of the two-input integration unit and the output with the input of the regulator of variable intensity of the drive speed change, and two second outputs of the digital calculator are connected to two inputs of the second key connected to the third input with the output of the three-input integration unit and the output with the input of the excitation controller. > 1107239 2 7 2. Δί ^ _ _τ = Ε (ω) Κ'Φ ~ losses in engine steel; motor excitation current; field winding resistance; . DR = UR + DR + J ² R + δΡ (ω | Σ