SU1300598A2 - Device for protection of inverter - Google Patents

Description

11, the signal from the output of the element AND-NOT 20 is fed to the input of the second element And 9, prohibiting the passage of the start pulse from the output of the delay unit 11 to the control electrode of the thyristor 3. As a result,

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The invention relates to converter equipment, can be used as the main link of thyristor generators and secondary power sources based on resonant inverters, and is an improvement of the device for protecting the inverter according to Aut. No. 1220052,

The purpose of the invention is to increase the reliability of protection of a resonant inverter in case of accidents in the load circuit of a resonant inverter.

The drawing shows the functional diagram of the device for the protection of the resonant inverter.

The device contains a blocking capacitor I, a resonant inverter 2, a thyristor 3, a switching reactor 4, a resonant inverter control unit 5, two current sensors 6 and 7, two elements AND 8 and 9, an OR element 10, a pulse delay unit 11, a HE element 12, standby multivibrator 13 and resistor 14, Block 5 of the control of a resonant inverter includes a master oscillator 15, a distributor 16 pulses, a pulse amplifiers 17. In addition, the circuit contains two additional elements OR 18 and 19, the element AND NOT 20 and the key 21.

In this case, the blocking capacitor 1 is connected between the terminals for connecting the power supply of the resonant inverter, one of which is connected to the power supply bus of the resonant inverter 2, the second power supply bus of which is connected to the second output for connecting the power supply51 via serially connected thyristor 3 connected in direct control board, and the switching reactor 4, and the control input of the resonant inverter 2 is connected to the output of the control unit 5 of the resonant inverter.

turns off from the power supply. In addition, the signal from the output of the second additional element OR 1C will go to the input of the key 21, which will turn off the master oscillator 15 of the control unit 5. 1 Il.

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two sensors 6 and 7 of the current, included in the circuit of power devices (thyristors) of the resonant inverter 2, are connected to the inputs of the first element AND 8, the output of which through the element NO 12 is connected to the input of the waiting multivibrator J3, while the output of the second element And 9 is connected to the control electrode of the thyristor 3, and one of its inputs to the output of the pulse delay unit P, the input of which is connected to the output of the OR element 10, whose inputs are connected to the additional outputs of the control resonant inverter 5, for which the outputs limiter 16 pulses, while parallel to the connected thyristor 3 and com-) guguyuschemu reactor 4 included resistor 14, in addition, the inputs of the first additional element OR 18 connected to the outputs of the sensors 6 and. 7 current, and its output - with one of the inputs of the element AND-NOT 20, the second input of which is connected to the output of the pulse delay unit 11, while the output of the element AND-NOT 20 is connected to one of the inputs of the second additional element OR 19, the second input of which connected to the output of the standby (its multivibrator 13, and the output to the second input of the second element I 9 and the input of the switch 21, the output of which is connected to the additional input of the control unit 5 of the resonant inverter.

The principle of operation of the device is to follow.

In normal operation, the resonant inverter 2 and the control circuit 5 of the resonant inverter, as well as accidents in the inverter 2, caused both by the accidental overturning of the inverter 2 and by the failure in the control circuit 5 of the resonant inverter,

The bot device is similar to the prototype, since the signal from the output of the standby multivibrator 13 through the second additional element OR 19 is fed to the input of the second element AND 9, thereby prohibiting the turning on of the thyristor 3. In addition, the signal from the output of the second additional element OR 19 on the INPUT key 21, which ensures the switching off of the master oscillator 15 of the control 5 unit by the resonant inverter, which facilitates the restoration of the working capacity of the resonant inverter. At the same time, the rest of the newly introduced elements do not affect the operation of the device, since the duration of the current through the power devices of the resonant inverter 2 is always less than the delay time in the pulse delay unit 11, i.e. the inputs of the element AND-20 at the same time the signals do not poslayut.

In the event of an accident in the inverter due to a fault in the load circuit, for example, the breakdown of isolation of the load circuit on any power supply bus of the resonant inverter power supply, the current pulse duration through the power device of the resonant inverter 2 increases. This is due to the fact that the input of the capacitor capacitance of the resonant inverter 2 occurs, which is much larger than the loop capacitor of the inverter 2. At the same time, two signals are simultaneously input to the input of the AND-NOT element 20 —one is from the current sensor 6 or the second: the output of the pulse delay unit 11. At the output of the AND-NOT element 20, a signal appears which, having passed through the second additional element OR 19, enters the input of the second element AND 9, prohibits the passage of the start pulse from the output of the pulse delay unit 11 to the control Tyris electrode ora 3. As a result, the resonant inverter 2 It appears disconnected from the power supply source

Editor i.Kyshtulinets

Compiled by O. Mescherkova Tehred L. Serdyukova

Order 1157/54 Draw 619

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

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neither In addition, the signal from the output of the second additional element OR 19 is fed to the input of the key 21, which ensures that the master oscillator 15 of the resonant inverter control unit 5 is turned off.

The key 21 may be performed according to any of the known schemes, for example, a transistor switch or a logic element.

Thus, the proposed device completely eliminates the emergency conditions in the power source and the resonant inverter due to failures in the load circuit, due to the fact that, compared to the prototype, the proposed device controls the duration of the current through the power elements. You have a resonant inverter and disconnect it from the power source when exceeding the duration of a predetermined value, which leads to a failure in the protection of the inverter.

Claims (1)

Invention Formula Device to protect the inverter auth.St. No. 1220052, that is, so that, in order to increase the reliability of the protection of the inverter in case of accidents in the load circuit of the inverter, two additional elements OR, the NAND element and a key, the inputs of the first additional element OR are connected to the outputs of the current sensors and its output is connected to one of the inputs of the NAND element, the second input of which is connected to the output of the pulse delay unit, and the output is connected to one of the inputs of the second additional element OR, the second input which is connected to the output of the standby multivibrator, and the output - to one of the inputs of the second element I and the input of the key, the output of which is intended to be connected to the input of the control unit - inverter, Proofreader A. Obruchar - i Subscription