SU1293786A1 - Device for checking serviceability of semiconductor converter - Google Patents

Abstract

The invention relates to converter technology, in particular, to devices controlling the protection of F (/ 8.; and diagnosing noloconductors of converters). The purpose of the invention is to enhance the functionality of the device to monitor the health of a semiconductor transformer by making it possible to determine a faulty valve. one

Description

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 The invention relates to converter technology, in particular to devices for monitoring, protecting and diagnosing semiconductor converters.

The purpose of the invention is to expand the functionality of the device for monitoring the health of a semiconductor converter by providing the ability to determine a faulty valve,

FIG. I is structural

The scheme of the device proposed in FIG. 2 is time1-P) e signal in reflecting the principle of the device, and the number on the ordinate axis corresponds to the positional designation of the element at the output of which this signal is present (voltage)

Control device to equate semiconductor converter,. containing three series-connected controlled valves 1-3 (fig.), mis-shunted with damping KS-chains 4-6, sensitive element in the form of a current transformer 7, secondary winding

through which the relay element 8 and the malfunction detection unit 9 are connected with the alarm elements 10-12 and the actuating element 13 of the protection, the block 9 includes the element 14 overdubs, elements 15-18 and elements Memory 19-2, B window the magnetic circuit of the current transformer 7 missed the conductors of the damping RC-chains 4-6. In addition, the device has an N-input element OR 22 (), serially connected pulse generator 23 and pulse distributor 24 with N outputs. Block 9 is complete with (N + 2)

input-; g1I and N outputs. The outputs of the pulse distributor are connected to the control unit and to the circuits of valves 1-3 and the first, N inputs of block 9, () -i input is connected to the input of relay element 8, (Y + 2) -th input - to the generator output 23 pulses, the first N outputs are connected to the inputs of the alarm elements 10-12 and, via the OR element 22, are connected to the input of the executive protection element 13. Block 9 has Y, i.e. Three channels linking the first three inputs to the corresponding outputs. The channels are formed by elements AND 15--17, the first inputs of the boiler serve as the inputs of block 9, and the outputs are connected to the input, 30

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cells 9-2K. The second inputs of the AND 13--17 elements are connected.: the output of the fourth (N + l) ro element of AND 18, the first input of which is the fourth (N-bi) -M input of the logical block 9 and the second through the delaying element 14 is connected with the fifth (mon- + 2) input of the block 9, the semiconductor converter B controls the group of controlled gates 1-3 connected to the power source through the current limiting element 25.

The device works as follows.

When a supply voltage is applied to the input of a value in the case of the health of all Benti- and capacitors of the damping RC chains 4-6, they are charged before the voltage. The impulses of the generator 23g entering the counting input of the distributor 24 cause alternating spacing} ; pulsing pulses in the valves 3 (see, the left part of the graphs in Fig. 2). If they are vented, then after submitting each imp; There is an exponential resolution of one of the previously charged capacitors of the RC chains, namely the one that is connected to the valve 3 to which the last impulse has arrived. After discharging the coil to the de- xor of the torus, the anode current of the corresponding valve becomes less than the holding current and the valve is turned off. When any of the capacitors is discharged, a positive polarity pulse is generated on the secondary winding of the current transformer 7, which is converted by the relay element into a logical O signal (Fig. 2). The output signal of the relay element 8 is fed to the first input of the element I 18, the second input of which is supplied by pulses of the generator 23 delayed by the element 14 of the delay by time T. Sutf {ar ary delay time T and the pulses of the generator 23 should not exceed the duration of the discharge current of the capacitor damping chains, therefore, -1u at the output of the element And 8, the level of the pogic 0% prohibits the passage of pulses from the outputs of the distributor 2 through the elements of the G5-17 channels of the shock signal to be permanently maintained. 9 This device operation mode indicates b serviceability eten --- lei 1-3.

If one or several converter gates are not turned on when the unlocking signal is applied, then at the corresponding time points at the output of the relay element 8 a logic level 1 is stored, indicating the absence of a discharge pulse in the primary conductors of the current transformer 7. In this case, at the moment when the delayed impulse of the generator 23 is output from the output-element 14 of the element I 18, a logical I signal also appears that permits the passage of a pulse from the output of the distributor 2D through the corresponding element I (15, 16 or 17). the memory fixes the faulty valve, and the protection actuator 13, due to communication with the outputs of logic unit 9 through the element OR 22, produces an emergency shutdown. Signaling elements 10-12 (for example, LED indicators) make it possible to unambiguously determine the number of the failed valve. In particular, the first part (Fig. 2) shows temporary ones. diagrams of the device operation mode when the first valve is turned off.

The need to introduce a delay between the moment of supply of the trigger pulses and the moments of the start of control of the presence of discharge pulses of RC chains is caused by the inherent actual controllable valves of the dead switch on the anode current, and therefore the time T should not be less than the delay time and buildup for valves used Otherwise, false positives of protection are inevitable.

In addition to detecting valves that do not turn on when the trigger pulses are applied, the proposed device allows an emergency shutdown of two more types of failures: if the RC snubber circuit is broken, when there is no voltage on the snubber RC snubber circuit. for the breakdown or spontaneous switching of the valve connected to it. In these two cases, the faulty valve is also fixed, however, additional hardware is needed to determine the type of failure.

Thus, the use of the invention allows to expand the functionality of the device, since it is possible to identify specific valves in the group that have lost control, as well as RC circuit malfunctions that lead to converter failures. This increases the operational reliability of the converters and facilitates fault diagnosis.

Claims (1)

Invention Formula A device for monitoring the health of a semiconductor converter executing on N controlled valves shunted by damping chains consisting of a series-connected resistor and a capacitor containing a transformer whose secondary winding is connected to the input of the relay element, the elements of memory, delay and coincidence are different that, in order to extend the functionality by providing the possibility of determining a faulty valve, a pulse generator is introduced and pulses, an OR element, as well as coincidence elements and memory in the amount of N-1 and N, respectively, and the toformator is equipped with N primary windings, each of which is intended to be connected in series to the damping chain of the corresponding valve, while the output of the relay element is connected c, the first input () -ro of a match element whose output is connected to. the first inputs of the remaining coincidence elements, the output of each of which is connected to the corresponding signaling element, and, through the OR element with the actuating element, the output of the pulse generator is connected to the input of the pulse distributor, and through the delay element is connected to the second input of Cf + 1) -th coincidence element The outputs of the pulse distributor connected to the second inputs of the corresponding coincidence elements are intended for connection to the control inputs of the respective converter gates.  All BsHmufli4 i (cnpaff Valve 1 me % fa Editor S. Lisin Compiled by VHChirokov Tehred I., Popovich Order 392/56 Tirs1Zh 619Subscription. VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk iab., d. 4/5 Production-polygraphic enterprise s g, Uzhgorod ,, ul, Projectkag Proofreader M. Pojo