SU1487011A1 - Adjustable dc voltage converter - Google Patents

Description

The invention relates to electrical engineering and can be used in secondary power supply systems for converting and stabilizing DC voltage. The aim of the invention is to reduce the size and weight and reduce bullets

of the current consumption. The converter contains an even number of cells of key voltage regulators with control transistors 1–4 and OE filters. All cells are combined into two groups. The outputs of the cells in each group are interconnected, while the outputs of the groups are connected to the primary windings of the output transformer 17 of the push-pull inverter with controlled keys 5, 6. Due to the fact that the control transistors 1-4 perform simultaneously the functions of the switch of the input regulator and the switch of the output inverter, the output transformer is made with one primary winding, which reduces the weight and dimensions of the converter. Performing a multiphase key controller allows you to reduce input current ripple. 2 Il.

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The invention relates to electrical engineering and can be used in secondary power supply systems for converting and stabilizing DC voltage.

The aim of the invention is to reduce the size and weight and reduce the ripple of the consumed current.

FIG. 1 shows a circuit diagram of a transducer with four stabilizer cells; in fig. 2 - diagrams of the converter operation.

The constant voltage converter (Fig. 1) contains a multiphase key voltage regulator with control transistors 1-4, a push-pull inverter with controlled keys (transistors) δ and 6.

The collectors of transistors 1-4 are connected to the first input terminal 7 of the converter, and the emitters through diodes 8-11 to the second input terminal 12 of the converter and through chokes 13 to 16 of the 16Δ filter to the collectors of transistors 5 and 6. The emitters of transistors 5 and 6 are connected to the second input terminal 12 of the Converter.

Between the collectors of transistors 5 and 6 is included the primary winding of the output transformer 17 of the push-pull inverter, the secondary winding of which is connected to the output terminals of the converter via a rectifier 18 and a filter 19. The control circuit of all transistors are connected to the outputs of the control unit 20.

The Converter operates as follows.

The control unit 20 generates the thyristor control pulses 1-6 in accordance with the diagram shown in FIG. 2 (a — e), respectively.

Transistors 1-4 are supplied with pulses interconnected for a time Τ / Ν, where T is the period of operation; N is the number of cells (transistors) of the stabilizer, and having an adjustable duration of γ7, where γ is the relative duration, adjustable from 0 to 1 in each cell.

The transistors 5 and 6 are served not regulated by the duration of the pulses of width 7/2.

When switching transistors according to this algorithm, voltages occur in the windings of chokes 13-16, as shown in FIG. 2 (f – k), from the condition of equality to zero of the average for the period of the voltage value on these windings

0.7 / 2 = (^ - ^) ( _γ 7-.7 / 2) + ί7 ^ (1-γ) 7, where is the input voltage;

- reduced to the primary winding of the transformer output voltage;

T - period; ·

y is the relative time of the open state of each key,

- four

we will receive control of the adjusting characteristic

Ki = and '„/ and„ = 2y.

The control characteristic is linear, but the output voltage is doubled.

The currents of the chokes 13-16 are determined by the voltages on the windings and are shown in FIG. 2 (l — o), respectively.

The sum of these currents (Fig. 2 ") is the current of the transformer 17 windings, and its variable component is the current of the output capacitor 19. The sum of the shaded parts of the currents, which are collector currents of transistors 1-4, determines the current consumed by the converter (Fig. 2p), and its variable component - input capacitor current.

From the analysis of the diagrams of FIG. 2 it follows that the currents of the input and output capacitors at γ = 0.75; 0.5 and 0.25 are zero, and for other values y is several times less than in the prototype.

Consequently, for a given quality (ripple) of the output voltage, the mass and dimensions of chokes and capacitors are significantly reduced compared to the prototype converter, and the execution of the output transformer with one primary winding further reduces the weight and dimensions of the converter as a whole.

The control unit can be made using any known digital type scheme (based on multiplexers, decoders, pulse distributors, etc., and a clock generator).

Claims (2)

Claim Adjustable DC voltage converter containing the first cell of a key voltage regulator with a series regulating transistor, one of whose power terminals is the input of the cell and is connected to the first input terminal, the second power output through the choke of the ΏΔ filter is with the output of the cell, the diode of the ΡΛ filter is turned on between the second power output of the transistor and the second input output, push-pull, an inverter with two controlled keys, one of the power supply terminals is connected to the first power output of each of which primary winding of the output transformer, the secondary winding of which is connected to the output terminals through a filter rectifier, the control unit, the outputs of which are connected to the control inputs of the regulating transistor and the controlled keys of the inverter, characterized in that. in order to reduce the size and weight and reduce the ripple of the current consumed, an odd number of identical cells of the key voltage regulators is inserted into it, 148701ϊ five connected in parallel with each other and with the first cell, all the cells forming a multiphase key voltage regulator and combined into two groups with an equal number of cells, the outputs of the cells in each group are interconnected, while the outputs of the groups are connected to the output windings of the output trans the formatter, the control inputs of the cells are connected to the corresponding outputs of the control unit, the second power outputs of the controlled keys of the inverter are connected to the second input terminal, and the control unit ensures the synchronous operation of the cells of each group of the multiphase controller with the corresponding inverter key. ^ 77777777, ^ LI_7Ζ77 // 77777777 77 //// 7 Fee 2