SU1267571A1 - Two-step inverter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in secondary power sources. , The purpose of the invention is to simplify the two-stroke inverter consisting of a magnetic switching element 1, transistors 2, 3, an output transformer (Tr) 4 with an output winding 5. The windings W, and w Tr 4 and the windings of the element 1 are placed on a common core 6 so, that their magnetic fluxes are perpendicular to one another, and in the core there is a nonmagnetic magnetic gap S that intersects the magnetic flux of the windings Tr 4. This arrangement of the windings allows us to simplify the device, while reducing the mass of magnetic elements due to more effective effective ispo Leaning of magnetic core material. 7 il. SL // go a | ate “vl

Description

The invention relates to electrical engineering, in particular to voltage converters, and can be used in power supplies of electronic equipment. The purpose of the invention is to simplify the device. FIG. 1-4 shows the options for performing a two-stroke inverter; in fig. 5 and 6 constructive execution of the output transformer and the magnetic switching element on one core with a gap crossing the magnetic flux of the windings of the output transformer; FIG. 7 mutual arrangement of the flux of the magnetic switching element and the output transformer. The push-pull inverter (Fig. 1-4) consists of a magnetic switching element 1, switching transistors 2, 3 (in de facto case, for example, for fig 1, and transistors 2, 3) and an output transformer 4 with an output winding 5 connects to the load, and the switching transistors 2, 3 are connected to the magnetic switching element 1 and the rotary transformer 4. The windings w, w of the output transformer 4 and the windings of the magnetic switching element 1 are placed on a common core 6 so that their magnetic fluxes are perpendicular they are one to another dechni ke vsholnen nonmagnetic gap S (Fig. 5, 6) crossing the magnetic flux of the windings W ,, W2 output transformer A (FIG. 7). We consider the device operation using the example of a push-pull inverter, shown in FIG. 1, When a UgK, Ugx voltage is applied to the input of the device, the switching transistors 2, 3 are biased, causing one of the transistors to avalanche open and saturation, and the other to be locked. A current flows through the winding of the magnetic switching element 1, leading to a reversal of the core in one of the mutually perpendicular directions and the appearance of voltages on its other windings proportional to the transformation coefficient of the windings of the magnetic switching element 1. The voltage on the base windings opens one of the commutating transistors 2 or 3, through which current also begins to flow, reversing the core in another mutually perpendicular direction. On the windings w ,, w of the output transformer 4, voltage is induced, and from winding 11 (output winding 5) it enters the load. The intensity and induction of the magnetic field for the magnetic switching element 1 are defined by the following relations: Iv H: p-; In, | U. (U I ,, for the output transformer 4, respectively: n - V P7 - (C l + / bS / Cep Then the switching of the magnetic nV of the switching element 1 is created when following 1 .-) the general condition that you set the values of В | and В , it is possible to set the switching frequency, and it is possible to redistribute the induction along the directions: a greater value can be set (by specifying the number of turns) in the core of the output transformer 4, and a smaller value to the magnetic pending element 1. Under the condition (1), the magnetic switching element 1 becomes saturated ( j dramatically changes its meaning and magnetizing current increases sharply, which leads to the switching of transistors 2 and 3 and to the beginning of the magnetization reversal of the core in this direction. After entering the locking pulses, the transistor 2 or 3 continues to pass a current, the magnetized core in the other direction, but since a nonmagnetic gap is introduced in this direction, there is practically no increase in current. According to the conducted research, the most optimal reduction of fi in the direction of flow of the output transferor should correspond to 400,600 for ferrite alloys from jti 2000, which corresponds to the introduction of a non-magnetic gap from 8 0.1 to 0.15 mm.

The value of S determines the correlating relationship between the fluxes of the magnetic element and the output transformer and is chosen from the condition of minimizing the dynamic losses when switching

SRI.

The operation of the push-pull inverters shown in FIG. When asymmetric re-magnetization, the magnetisation current of the output transformer in the switching half-cycle has different values, therefore, the half-periods are also different in time, (since the switching of the transistors is determined by the expression (I), the half-period varies in such a way that current relative to the symmetric mode of operation.

In known solutions, when the device is turned on, the core of the magnetic switching element and the core of the output transformer are demagnetized over different cycles and in a number of cases, when the output transformer is disconnected (by a relay and another switch), the core retains 80% of the latter. Upon subsequent switching on, if the magnetic field direction coincides with the residual magnetization, the magnetic induction of the output transformer core quickly reaches saturation and a transient current jump occurs with a significant amount of the Transient current when switching on or any other switching in the proposed device, since the output transformer (magnetization) associated with the induction of a magnetic switching element. This connection is defined by the expression (I), which defines the switching mode of the transistors at different switches and external influences.

Thus, placing the windings of the output transformer and the magnetic switching element on one core of a non-magnetic gap crossing the magnetic flux of the windings of the output transformer helps simplify the device, while reducing the mass of magnetic elements by more efficient use of the magnetic core material, as well as eliminating transient currents in The moment the device is turned on.

Claims (1)

Invention Formula Two-way: an inverter containing switching transistors, a magnetic switching element and an output transformer with a load in the output circuit, the switching transistors being connected to a magnetic switching element and a high-voltage transformer, in order to simplify the device, the output transformer and magnetic winding switching element placed on one core so that their magnet-Hbie flows perpendicular to RnR one to another, while the core is made with a nonmagnetic gap, crossing the magnet the flow of windings of the output transformer. Iff 0 USK i 2 5 fJbblX, -o (rig 2 (pwe.J Iv. W (/. . 2: d 2 /,