SU1431019A1 - Protected transistor converter - Google Patents

Abstract

The invention relates to electrical engineering. The aim of the invention is to increase reliability. The permissible overload is determined by the choice of the capacitor capacitance 6. The magnitude of the ripple amplitude of the supply voltage (determined by the capacitance value of the capacitor 6) of the power amplifier of the protection unit 8 also determines the value of the overload current at which the power supply voltage of the power supply unit 8 fails zero and stall generation. At a certain magnitude of the overload, the circuit will go into operation in the mode of start pulses and the current of the overload decreases to current in the mode of start pulses, i.e. about ten to one-time. The current in the output circuit will never exceed the set value for a JDO fault in the circuit. If the power supply circuit is broken, or the power amplifier of the protection unit 8 itself malfunctions, or the resistor 3 is broken. Inverter 1 does not work. When the smoothing capacitor 6 breaks, the circuit will be disconnected with a low pressure (L

Description

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1А31019

Our load will be significantly lower than the power and at load 11 will be real, since the pause between the pulses will only be triggered, the pulses will turn off the amplifier 2 or less.

The invention relates to electrical engineering and can be used to protect transistor converters of secondary power sources.

The aim of the invention is to increase reliability.

Fig. 1 shows a functional diagram of the converter, Fig. 2 shows timing diagrams.

The transistor converter with protection contains an inverter 1 with a control unit 2 connected to the common bus through the sensor 3 output current of the inverter}. One of the secondary windings of the output transformer 4 of the inverter t is connected to the input of the rectifier 5, the output of which is bypassed by the capacitor 6 and connected to the collector of transistor 7 of the protection block 8 japped in the form of a power amplifier, the out-of-phase outputs of which are connected to the inputs of the control unit 2 of the inverter 1. The emitter of transistor 7 through a capacitor 9 is connected to the output pulse of the generator 10 pulses. The output of the triangular voltage is connected to the base of the transistor 7. Another secondary winding of the transformer 4 under Klvochena. to load 11.

The converter works as follows

When the supply voltage is turned on, the pulse generator 10 begins to generate square and triangular voltage pulses (U and Fig, 2) s, which go to the power amplifier of the protection unit 8, and the square voltage pulses after the capacitor 9 have a minimum the required duration to start the device (Uj, FIG. 2),

The start-up pulses (U, FIG. 2) include for the duration of their operation the control unit 2, which turns on the inverter t and on the secondary

The voltage of the transformer 4 is formed, which, after being rectified by rectifier 5 and smoothed by capacitor 6, is fed to the amplifier 5 of the power of protection block 8. The power amplifier of the protection unit 8 thus receives power and generates anti-phase reinforced triangular voltages at the outputs (Uj, U, Fig. 2),

0 incoming to the inputs of the unit 2 controls the bridge with inverter 1, i.e. trigger pickup occurs, and the circuit starts up. The control unit 2 forms antiphase square voltages (U and

and FIG. 2) controlling the operation of the inverter 1, and on the output winding connected to the load 11, the output voltage Ug, co0

five

This is the result of a sequence of pulses ty and pause tjj (Fig. 2). The duration of the pulses and pauses of pho1 is ensured by the control unit 2. In control unit 2, the triangular voltage is compared with the voltage drop across the resistor-sensor 3 of the output current of the inverter 1. The larger the load current, the greater the voltage drop on the resistor 3, the smaller the duration of the square voltage pulses. and U-, (Fig. 2), and, consequently, the duration of the open state of the power transistors of the inverter 1.

5 As a result, at load 11, the duration of the ty pulses decreases, and the duration of the pause t increases (Ug, Fig. 2). The load current is stabilized.

0 The value of the rated load current is determined by the choice of the resistor-sensor 3 of the output current of the inverter 1. The permissible amount of overload is determined by the choice of capacitance

5 capacitor 6. Without capacitor 6 in the supply voltage of the power amplifier of the protection unit 8, coming from

In the mittel 5, voltage dips will be present in the pauses t between pulses t (Fig. 2). Therefore, the magnitude of the load current at which the failure of the power supply voltage of the power amplifier 8 of the protection unit 8 goes to zero and the generation failure occurs depends on the magnitude of the ripple voltage of the supply voltage (determined by the capacitor 6 capacitance value). At a certain amount of overload, the circuit will go into operation in the mode of start pulses and the current of the overload will decrease to the current in the mode of start pulses, i.e. about 10 times.

The current in the output circuit will never exceed the set value for any damage in the circuit. For example, when the power supply circuit breaks, the power amplifier itself, or the power amplifier of the protection unit 8 itself malfunctions, or the resistor 3 breaks, the inverter 1 does not work. When the smoothing capacitor 6 is broken, the circuit will be disconnected at the slightest load, well below the nominal, since the pause between pulses will turn off the power amplifier and the output, i.e. on load 11

only trigger pulses will be active.

Thus, due to protection against overloads and short circuits in the load, inverter trips and faults in the circuit, the reliability of the converter operation is increased.

Claims (1)

Invention Formula Protected transistor converter, contains an inverter with a control unit and an output transformer, one of the secondary windings which is connected to the input of the receiver, the protection unit on the transistor, the output current sensor of the inverter and the capacitor, which is characterized by the fact that it is equipped with a pulse generator to ensure reliability, and the protection unit is designed as a power amplifier with antiphase outputs connected to the inputs control unit, emitter the transistor is connected to the pulse generator start pulse output, its base is connected to the triangular voltage output of the pulse generator, and the collector is connected to the output of a capacitor bridged capacitor, the control unit and the inverter are connected to the common bus through the inverter output current sensor. About U LJ U gitee, 2