SU809458A1 - Method of regulating balancing current in reversible power-diode converter - Google Patents

Description

The invention relates to electrical equipment of extended plants, namely to automatic control systems of direct current drives powered from reversible static converters with joint control of rectifying groups, and can be implemented in many industries for reversible direct current drives controlled by the principle of successive correction. A known method of regulating an equalizing current in a reversible valve converter that supplies a direct current electric motor, in which the equalizing regulator of a valve converter is blown through a negative feedback circuit with a signal of an adjustable parameter, measure the derivative of the frequency of rotation and, in order to reduce the dynamic component of the equalizing current, additionally on the indication of the controller, the signal is influenced by the proportions of the first indicated error per hour Tote of rotation 1. The disadvantage of this method of controlling the dynamic equalizing current of a reversible converter is the poor quality of the transition process in a certain zone of the ratio of the dynamic parameters of the core circuit and the equalizing circuit. This deficiency cannot be eliminated by this method, since when the capacitor is switched on parallel to the diode, the signal of the surge current regulator has the form (l + pTj) K and, consequently, when the input parameters (capacitance and resistance) change, the time constant T and the gain factor change simultaneously K. The closest technical solution to the invention is a method for regulating an equalizing current in a reversing gate converter that supplies a direct current motor, in which an equalizing current regulator and the gate converter is affected by a negative feedback circuit with signals of an adjustable parameter and a derivative of the current value of the rectifier group 2. The disadvantage of this method is the delay of the signal of the derivative of the rectifier group's current value with a disturbing effect: over load, which leads to an increase The dynamic component of the drive is € 1Pn current compared to the control mode. The purpose of the invention is to reduce the dynamic amount of equalizing current. This goal is achieved by the fact that, in addition, the regulator of the balanced current is affected by a signal proportional to the first produced voltage on the direct current electric motor. The drawing shows a diagram of a reverser valve converter. It is equipped with a two-channel rotary motor with a two-channel rotational speed control system. The circuit contains the object to be controlled — a direct current motor 1 of independent excitation; rectifier current regulator (inverter) circuit consisting of the control object 1 of converters 2 and 3 with systems 4 and 5 of phase control of current regulators 6 and 7, current sensors 8 and 9, equalizer current setpoint 10, a logic switch device 11 and a correction link 12 with a voltage sensor 13 / motor speed control loop, consisting of the control object 1 in the form of a current control circuit of the rectifier (inverter) according to position b, and the regulator 14 often , speed sensor 15. With a control signal, the signal from the setpoint of the rotational speed of the engine Pzdd programs the change in time of the rotational speed of the engine and the direction of flow of the signal from the corrective element 12, for example, when the condition is forward to the regulator 7 current, at the reverse direction - to the regulator b ok a The exact transfer function of the correction link 12 is equal to the inverse transfer function of the current control circuit — the thyristor converter, P,;, T PIllil.JiL, Р, Р Т ,, -t- Чк э, where Tr is a small time constant of the current loop; - constant time of the chain; m is the ratio of the equivalent constant times of the speed control loops to the motor current; K - coefficient of force of the sensor. current; R-J is the resistance of the engine crown chain. The implementation of link 12 is not possible, therefore in real installations it is supposed to use a link with an approximate transfer function; (. .Jil. (2) -pTj-CRE where Td T + Tj. The first operating mode of the drive. When the drive is running forward to the control input A torus of a rectifier current is supplied by the algebraic sum of three signals: setting the rectifier current from the output of the rotational speed controller 14, setting the equalizing current and negative rectifier current feedback from the rectifier 8. The current regulator b supplies a signal to the converter such h to ensure optimum forward current of the rectifier in time. The transient functions of the rectifier current and the EMF of the engine with the given parameters of the main circuit and equalizing circuit determine the behavior of the main engine voltage that is disturbed in the circuit of the equalizing current control. To compensate for this disturbance, t to eliminate the surge of a dynamic equalizing current, it is necessary to input a current regulator 7 (regulating current regulator) to introduce a signal proportional to the voltage of the motor core through correction link 12, the transfer function of which is equal to the inverse transfer function of the path of the current regulator 7 - converter 3. With a positive signal Dp at the input of the regulator 14 of the rotation frequency (or back) the logical switching device 11 is activated and the signal of the negative feedback from the correction link 12 is supplied to the input of current regulator 7. Furthermore, the current regulator 7 is supplied with a signal for setting a balancing current and a negative feedback signal for a balancing current from current sensor 9. . The current regulator supplies the converter 3 with such a signal in order to ensure that the dynamic equalizing is equal to zero, i.e. the voltage of the converter 3 will repeat in time the core voltage of the motor and the magnitude of the voltage drop in the inverter circuit from the static component of the surge current will differ from it. The second mode of operation of the drive. When the drive is running back to the input of the inverter current regulator 7 is fed

the algebraic sum of the three signals, the setting of the inverter current from the output of the rotational frequency controller 14, the equalization current and the negative current feedback of the inverter from the current sensor 9.

4 A current pulse 7 provides the converter 3 of this form with a signal in order to ensure the optimal behavior of the inverter current over time.

To compensate for the disturbance in the form of a stresses, i.e. In order to eliminate the surge of the dynamic equalizing current, it is necessary to input the signal from the voltage sensor 13 through the correction link 12 to the input of the current regulator 6 (regulator of the surge current).

With a negative signal Ap, the logical switching device 11 is activated and the negative feedback signal from the correction link 12 is applied to the input of current regulator 6. In addition, the regulator 6 is supplied with signals for setting an equalizing current and negative feedback for an equalizing current from current sensor 8. The voltage behavior of converter 3 is similar to the voltage behavior of converter 2 in the first drive mode.

Using the proposed method for adjusting the surge current in a reversible valve converter reduces the drive loss, increases the power factor of the installation, since the surge current is reactive and also improves drive performance by reducing the rise time of the DC current of the DC motor.

Claims (2)

1. Shtelman E., et al. Issues of a surge current in a two-channel system of subordinate regulation. Instructions electrical engineering design 0 industrial installations GPI T zhpromelektroproekt, - Energy, 1970, № 9. 2. USSR author's certificate number 299927, cl. H 02 R 5/06, 1971 5 (prototype).