SU1543518A1 - Parallel resonant inverter - Google Patents

Abstract

The invention relates to converter equipment and can be used in power supply, automation and communication systems. The purpose of the invention is to extend the functionality of a parallel resonant inverter while maintaining reliability in transient conditions by strictly limiting the voltage at the midpoint of the resonant circuit at a given level. Inverter (N-2) supply drossel 5, (N-2) additional drossel 8, (N-2) diodes 7 and (N-2) interlock capacitors 6 are inserted into the inverter. To improve the inverter’s weight and size parameters, all windings of supply and additional chokes are made identical and magnetically coupled, forming one multiwinding choke. 1 hp f-ly, 1 ill.

Description

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The invention relates to converter technology and can be used in power supply, automation and communication systems.

The purpose of the invention is to expand the functional capabilities of a parallel resonant inverter while maintaining reliability in transient modes by strictly limiting the voltage at the midpoint of the resonant circuit at a predetermined level nE, n times the supply voltage E.

The drawing shows the scheme of the proposed inverter.

The inverter contains two power transistors 1 and 2, the emitters of which are connected to the first input terminal for connecting the power source, and a parallel resonant circuit 3 is connected between the collectors, the choke of which is tapped from the midpoint of the winding, connected through 5 "series-connected chokes n, 5П2, ..., b / c with the second input terminal of the inverter for connecting the source k of the power supply, additional chokes 8H, 8, 28,

also connected in series so that the first output of the winding of the choke

8 is connected to the first output of the inverter to connect the power source k, and the second winding terminals of the respective power supply and additional chokes are connected by blocking capacitors 6 "(, 6" ,,, ..., b, the second winding leads of the additional chokes are connected to the first the leads of the windings of the respective power chokes through the diodes 7Y.1, 7ts ..., 71, connected in opposite with respect to the polarity of the blocking capacitors.

The inverter works as follows.

Transistor switches 1 and 2 alternately commute input square excitation pulses, alternately connecting the leads of circuit 3 to the first input pin. The circuit is excited by rectangular pulses of current accumulated by successively connected supply throttles 5 (- 5 high inductances

When the excitation pulses have a duty cycle that is different from two, either in the mode of overlapping currents, or when operating, the disconnected circuit {in the mode of frequency modulation4 voltage

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The lecturer, applied to the closed transistor in the open state time interval of another transistor, exceeds the supply voltage E more than 3.1 times. At the same time, at the midpoint of the winding of the throttles of the oscillating circuit, the voltage amplitude exceeds 1.57E.

Each of the blocking capacitors 6, -6H (charged before the supply voltage E through the respective windings of the supply and additional chokes 5 and 8.

With open diodes 7f - 7rtM, capacitors 6 (- 6 "are connected in series, the total voltage on them is (n-1) E, and the voltage at the midpoint of the winding of the oscillating circuit in relation to the first input terminal of the inverter is severely limited at the level of If the voltage at the middle point of the winding of the chokes of the col- umn circuit is less than n, the diodes 7j 7 "are closed and the amplitude limiting circuit does not affect the operation of the inverter. The number of chokes 5, - 8, - 8 „,, diodes 7g - 7 , Capacitors 6f - 6 "are selected such that the voltage at the middle point of the choke coil circuit 3 in the steady operating mode is not exceeded

Level 5 PI, i.e. n-1 diodes, n-1 blocking capacitors, n-1 additional chokes are necessary for n-fold limiting. When a load is lost (load shedding or voltage of the transistor), the current of chokes 5 (5 ", is interrupted, the voltage on them under the action of self-induction capacitance increases, however, when at the midpoint of the winding loop contour

5, the voltage reaches the level pE, the diodes 1L - 7t turn on, and the further growth of the voltage is severely limited. Accordingly, the voltage on the collectors of the closed transistors is limited, which ensures high reliability in transient conditions and with electronic regulation of the output voltage.

The throttles 5 (- 5 "1 and P, - 8", are connected in high frequency in parallel, since their terminals are connected in pairs by blocking capacitors 6, - 6,. To ensure a given sufficiently large inductance between

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the middle point of the winding of the chokes of the oscillating circuit 3 and the second input terminal of the inverter inductance Si chokes - 5b.,) and 8, - 8.f should have a significant value, which leads to an increase in the mass and size of the choke system.

For example, in the case of equal inductances of all chokes, the equivalent inductance of their parallel connection is halved, which requires a corresponding increase in the inductance, size and mass of each throttle. In order to improve the inverter mass-size parameters, all windings of the main and additional chokes are made identical and magnetically connected, i.e. form a single multiwinding choke with a common magnetic core. At the same time, the number of coiled goods in the device is reduced by p / 2 times, and the number of turns in each winding of the throttles is reduced by J2 (n-1) times, which allows to simplify the design by using only one wire from two multi-section windings and reduce losses windings and magnetic conductor0

Claims (2)

1. A parallel resonant inverter containing two power transistors, the emitters of which are connected to the first input terminal of the inverter, and a parallel resonant circuit is connected between the collectors, the choke of which is diverted from the middle point of the winding, the supply choke connected by the first winding terminal to the second input terminal of the inverter, first choke connected first . lazy dew prit ktiv- unifying the tivgae unit of the body and Verissa Yelkoki None Willow ten 15 20 25 thirty 35 40 a winding terminal with a first input terminal, a blocking capacitor connected between the second terminals of the auxiliary and supply chokes, and the second terminal of the additional throttle is connected to the second input terminal of the inverter through a diode connected in opposite to the polarity of the power source, characterized in that extending functionality while maintaining reliability in transient conditions and when adjusting by severely limiting the voltage at the midpoint of the throttles of the resonant circuit at nE, n-times power supply E, n-2 supply, n-2 additional chokes, p-2 blocking capacitors and n-2 diodes are inserted, the windings of the supply chokes are connected in series, and the second output of the last winding is connected with a tap from the midpoint of the winding of the throttles of the resonant circuit, additional chokes are also connected in series, the first terminals of the inserted supply and additional chokes are connected by blocking capacitors, and the second output of each additional chokes is connected to the first corresponding terminal of the supply throttle through diode connected in antiseries with respect to the polarity of the blocking capacitors. 2. The inverter according to claim 1, characterized in that, in order to improve the weight and size parameters, all the windings of the supply and additional chokes are made of magnetically connected, forming one multi-winding choke with a common magnetic core.