SU928607A1 - Current inverter control device - Google Patents

Description

(5) METHOD OF INVERTER MANAGEMENT

I

The invention relates to a conversion technique and can be used in high frequency thyristor converters.

A known method of controlling an inverter, consisting of a switching reactor, a thyristor cell with main thyristors, a load having a capacitive character, and a control system, consisting in that control impulses are fed to the main thyristors of the inverter with an adjustable forward angle b. wives As the angle fb increases, the output voltage of the inverter and the circuit time for recovery, the thyristors increase, and when fi decrease, they decrease. The upper limit of the inverter output voltage regulation is limited by the maximum allowable voltage on the elements of the inverter circuit, and the lower limit is limited by the smallest allowable circuit time for

thyristor recovery, which, for the inverter to work, must have a value equal to or greater than the thyristor off time. The circuit time for thyristor recovery is a variable parameter depending on the mode of operation and the parameters of the inverter., P.

Also known are inverters containing an additional thyristor, a shunt choke in the opposite direction. The additional thyristor can be controlled by methods of single, multiple or periodic unlocking in order to ensure the start-up of the inverter, protect the circuit elements from overvoltages and during emergency conditions, as well as to change the characteristics of the inverter.

Claims (2)

The closest in technical essence to the present invention is a control method in which the unlocking of one additional thyris: h pc1 o} pr ;. The circuit for the current commuoil:; rcmktora past the main u) is used: v7 () p and on. Inverter mine. This DOG g; L1-; GGLG- (LONG TYRISTOR USES p. Tol, o; 1; when starting the inverter, oM) / V- - D tny otpryz and. and in the established mode of operation, the pulses with r and 1 eis 1 org:. Further, the power switches igr1p :: rtorc1 are switched similarly 2. P yu J and p ov I i- and e of such a n i e rt o ro hau -, o (n (), n pp and ime p, c c g; and nutritional care -;; current, which requires the use of a p-1A at the input of a controlled rectifier, This reduces the coefficient of my power: -, 1po;: - an inverter without means of ryry-DOF5ni-i:.; be calculated for the whole of d, - ;;:; ir 3Or changes of the parameters of gitani and load, i.e. to have a reserve i (o; if-rv.: u .; -; Ti-iHOi-i of stability, whats n |:) X ; -hf) 1 and g to overestimate the established MOi.-i.HocTi-i ko1-: de; The aim of the invention is to improve |; .1 blueprints of the coefficient of mosh.nity and improve: The delta circuit is achieved by those in the manner in which the current inverter is used. c:) I hold it to the converter bridge on T1 resistors with a commutating capacitor in the diagonal of alternating current and sg.pisaivayuyitsI droselem from the direct current circuit, and smooth, dm and throttle is bridged by an H.7iM thyristor, I conclude the cs in alternate switching, the thyristors of the bridge and the thyristor, in the flow - / ie the interval; and the repetition is unlocked by the corresponding thyristors of the bridge, and then unlocked with a certain angle P JylipoEa; -; n and the reverse thyristor. and the zone -1 |; OEa of the output voltage Osu:, is indicated by changing the indicated value of rri. ria Srig, 1 is a diagram of a parallel current inverter with an additional thyristor, used as an example to illustrate the proposed method; FIG. 2 timing charts of the inverter. The inverter consists of a switching reactor 1, a thyristor cell 2 load 3; an additional device -1 and a control system 5. The additional device is represented by neither, 3 anode - to the common point of the reactor 1 and the thyristor cell 2. The thyristor cell contains one 7 and 8 and second 9 and 10 groups of the main inverter thyristors. The load must have a capacitive nature; it consists of a switching (compensating) capacitor 11, a reactor 12 and a resistor 13. The inverter operates as follows. Let the thyristors 7 and 8 of one group of the main thyristors of the inverter conduct. The voltage on the thyristor 6 is equal to the voltage on the switching reactor 1, i.e. the algebraic sum of the voltage of the power source and load, and during the conduction interval of the thyristors 7 and 8, which is less than the half-period of the same frequency, a straight line is applied to the thyristor 6 voltage. When the thyristor 6 is unlocked with the advance angle | 3, the current of the switching reactor 1 is closed through the thyristor 6, and the currents of the power source and load fall to zero. When unlocking with the advance angle f) of thyristors 9 and 10, the second group of main thyristors of the inverter thyristor 6 lock up H1, keni, equal to the sum of the voltage of the power supply and the load applied to it in the opposite direction of power. The current of reactor 1 flows through the thyristors 9 and 10 and the load, forming the second half of the load current, the duration of which is equal to the time interval between unlocking the main thyristors 9 and 10 and the additional thyristor. By changing the angles of advance and control of the main and additional: by using the inverter circuits of the inverter, you can make a pulse-width pulse | clearing the load current, as well as changing the value of the inverter output voltage and the circuit time to restore the main and additional thyristors in the desired direction. The application of the present invention allows the use of thyristors with lower dynamic parameters and overestimated off-time values in inverters with increased frequency, as well as the development of inverters at a higher starting frequency. Higher harmonics of the inverter output current are reduced. consequently, losses. By means of the control system, it is possible to carry out deep regulation of the inverter output voltage, which makes it possible to use an unregulated rectifier as part of the thyristor frequency converter. Claims An inverter control method comprising a thyristor converter bridge with a switching capacitor in an AC diagonal and a smoothing choke in a DC circuit, the smoothing choke being bridged by a turn-off thyristor . ± 1U-gt 12 13 at V 76, the next switching of the thyristors of the bridge and the reverse thyristor, characterized in that, in order to increase the power factor and improve the weight and size parameters, the corresponding thyristors of the bridge are unlocked during the repetition interval, and the control voltage of the output thyristor is unlocked carried out by changing the angle. Sources of information taken into account in the examination of 1. Berkovich E.I. and others. Thyristor converters of high frequency. L., Energie, 1973. 2. USSR Copyright Certificate W (1359, class H 02 R 13/16, 01.30.7  iTS pn