SU587577A1 - Self-sustained three-phase inverter - Google Patents

Description

one

This invention relates to devices.

to convert direct current into alternating current, namely, those of them that are made only on semiconductor devices, and can be used to control the speed of rotation of AC motors, in particular, in transport installations.

Autonomous inverters are known, consisting of valve groups, each of which contains two series-connected main controlled valves, and a reverse current circuit, and an artificial coupling circuit, squeezing the choke, auxiliary ynp aieles and fans; sator, .connected, .to source, subtitle

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In known trehfaEnyhavto omnY inverters with -9bis ydtpqycT m, noy: prinuditolnoy iypulsyrYa kommutayii N are separate and CHN-Ikoma-recharging, 3. switching .krydenoatrra containing basic and fKOMfryrHjjiyTOiiUie thyristors and tsegg ". current, additional discharge circuits of the switching capacitor through reverse current diodes are formed, which reduce the efficiency of the inverter and worsen the process of switching off the main thyristors. Such self-contained inverters have low efficiency, high weight, gabrnt and do not provide a wide range of output voltage frequencies due to unreliable switching off of the main thyristors.

The aim of the invention is to improve efficiency and reduce weight and size indicators.

This goal is achieved by the fact that in a stand-alone three-phase inverter, containing the main thyristors connected to the input terminals of the main thyristors and the chains of two additional thyristors, which are connected to the LC circuit, are connected to a terminal with the outputs of the bridge bridge. switching tsristoro and included in the diagonal of the alternating current Ojtzadzardnyh thyristors, connected to the inputs for connecting sources of charging, (introduced two last e ege connected and connected oppositely with thyristor thyristors auxiliary x thyristors, a common point of which is connected to a primary point of the UC-chain;

Claims (3)

Figure 1 is a schematic diagram of an autonomous inverter; Fig. 2 shows diagrams (oscillograms) of the distribution of control pulses on the inverter thyristors. An autonomous three-phase inverter spans the main thyristors bridge 1-6, skinny thyristors 7-12, additional thyristors 13,14, sub-thyristor bridge 15-18, connected to a subcharger and U source, an LC chain is included in the bridge diagonal, consisting from switching capacitor 19 and limiting choke switches 20, two series-connected auxiliary thyristors 21, 22, connected. counter to the power source. The inverter works as follows. Let the main thyristors 1.5 and 6 be open, and the load current passes from phase J (to phases B and C.) At the same time, a voltage is connected to the capacitor 19, the polarity of which is indicated in the diagram. switching on the thyristors 7g 13 and 22, the capacitor 19 is discharged, beyond the main circuit, and is recharged from the source of the power supply C, through the load with reverse polarity. The reactive load current flowing in the previous direction, wound through thyristors 22 and 7, thanks to what it provides ipperr 1 When a load current flows in another direction, thyristors 10,11 or 12 and thyristor 21 open. Diagrams 1 (oscillograms) of distribution of control pulses on the thyristors of the inverter realize the control principles of the inverter L "H50 el.grad, i.e. nor the main thyristors 1-601 150 e l. hail, which allows to get the voltage at the output of the inverter with the lowest content of higher harmonics. The duration of the control pulse of the main thyristors is 120 eh.grad. Claims of the invention A stand-alone three-phase inverter comprising a bridge of main thyristors connected to the input terminals and a chain of two additional thyristors, the point of which is connected by a cUC-chain connected to the DC terminals of the switching thyristors bridge and connected to the AC diagonal of the bridge back thyristors connected with connection for charging source, characterized in that, in order to reduce weight and size and efficiency,: it is equipped with two, sequentially These are connected with the main thyristors, auxiliary thyristors. Both the KOTOPi points are connected to the common net of Lt uenoi4KHv,. - Sources of information taken into account during the examination: 1. The author's certificate of the USSR 192915, cl. H 02 M 7/48, 1967. 2. Authors certificate of the USSR 232361, cl. H 02 M 7/48, 1969. 3.Slezhanovsky O.V. et al. The state and prospects of development of the three-speed electric actuator .M., Informelect1972, fig.18. about