SU1307506A1 - Device for identifying faults of inverter mode of converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used to diagnose inverter mode faults in a converter in a DC thyristor electric drive system. The aim of the invention is to simulate a device for diagnosing violations of the inverter mode. At the moment of commutation of the valves of the converter 11, there are short-term closures between the ends of the secondary winding of the power transformer 3, leading to the formation of pulses at the beginning of the secondary winding of the auxiliary transformer 2 and the input of the photopod bridge 4. However, these pulses can pass to the output only if they are illuminated Photodiodes by LEDs of the LED bridge 8, which is powered by pulses synchronized with the moments of passage through the bullets of linear voltage current, i.e. in conditions of beginning inverting inverter. The emulsions from the output of the photodiode bridge 4 through the diode 5, which is intended to exclude 1 reverse polarity pulses, arrive at amplification of pulses 6 and then to the protection actuator. The resistor 9 serves to provide the required intensity of the LEDs of the LED bridge 9. 2 Il. (O (L so O E ate Oi

Description

The invention relates to electrical engineering, in particular, to devices for measuring, controlling and protecting AC / DC converter converters (rectifiers), and can be used in particular to diagnose faults in the inverter mode of the converter in the DC thyristor drive system.

The purpose of the invention is to simplify the device to zero. Therefore, in this case, there is no signal at the input of the amplifier 6 pulses. The pulse generator 7 generates a three-phase system of pulses synchronized with the moments of transition of linear voltages on buses 15-17 of alternating current through zero values. Therefore, the ignition moments of the LEDs of the bridge 8 are also synchronized with the moments of transition through zero values.

VA for diagnosing inverter linear voltage faults on tires 15-17.

With an increase in the load of the converter, its current becomes continuous, which is accompanied by switching of the power thyristors in bridge 4. At the moments of switching, the two phases of the secondary winding of transformant 1, containing a low-power transformer 2, are connected to the primary winding mode.

FIG. 1 shows a diagram of a converter with a device for diagnosing violations of the inverter mode; in fig. 2 - diagram of a three-phase generator

The pulses entering the device for dialer 3 are short-circuited for a short time in order to disrupt the inverter mode. leads to the appearance of a voltage pulse. In FIG. 1 shows a device for the diagnosis of the secondary winding (in the corresponding

phase 2 of the transformer 2. However, the photodiode bridge 4 can skip these impulses parallel to the primary winding of the jn-pulses only under the condition that the ground transformer 3 and the ends are turned on and the current of the reverse direction winding goes to the secondary laziness corresponding photodiodes of this

the bridge. The forward current is cut off by diode 5. For the stated reason, the pulses at the output of bridge 4 can occur only when the switching points in the converter coincide with the luminescence times of the corresponding LEDs in bridge 8. This bridge is powered by a generator of synchronizing pulses that appear in points of transition line 30

power transformer windings (if the converter is transformerless, then transformer 2 is connected between the ends of the current-limiting reactor windings). The free beginnings of the secondary windings of the transformer 2 are connected to the input terminals of the photodiode bridge 4. The output of bridge 4 through diode 5 is connected to the input of the amplifier 6 pulses. The output of the generator 7 clock pulses through the LED bridge 8, which forms optocoupler pairs with the photodiodes of bridge 4, is loaded on a resistor 9, and the output of the pulse former 6 is connected to one of the inputs of the pulse-phase control system 10 of the converter 11 and the input of the protection executive body of the above converter ( protection system is not shown).

FIG. 2 shows a diagram of a three-phase generator of 7 pulses synchronized with the moments of transition of linear voltages through zero value.

The generator contains resistors 12-14 connected to the phases 15-17 of the AC network, as well as dynistors 18-20 and diodes 21-23 connected in pairs in series between the output terminals 24-26 of the generator. The voltage designations in the time diagrams of FIG. 2 correspond to the numbering of the circuits in the generator circuit.

The device (Fig. 1) works as follows.

The transformation ratio of transformer 2 is equal to the transformation ratio of power transformer 3, therefore, in the absence of current or intermittent current in the converter load and indicated by the switching points of the secondary windings, the voltage at the input of the photodiode bridge 4

35

40

45

voltage of the mains through zero, i.e. at the points corresponding to the angles p of the advance of the inverter, equal to zero.

Thus, the pulses at the input of the amplifier 6 pulses in the TC only if the switching of the converter occurs at (3 0, i.e. when the inverter starts to overturn. The driver 6 performs the functions of a normalizing converter, i.e. it amplifies the pulses to the desired amplitude in voltage and current.Resistor 9 serves to load the LEDs with current corresponding to their normal luminescence.

The proposed device is much simpler known, since it does not contain current sensors in the converter phases and includes significantly fewer elements.

Claims (1)

Claims of Invention A device for diagnosing disturbances of an inverter mode of a converter 50 equipped with a three-phase power transformer connected between the terminals of an alternating current network and the corresponding outputs of an alternating current of a converter bridge, containing a three-phase generator of pulses synchronized with the moments of linear voltage of an alternating current passing through a zero value different in order to simplify. 55 equals zero. Therefore, in this case, there is no signal at the input of the amplifier 6 pulses. The pulse generator 7 generates a three-phase system of pulses synchronized with the moments of transition of linear voltages on buses 15-17 of alternating current through zero values. Therefore, the ignition moments of the LEDs of the bridge 8 are also synchronized with the moments of transition through zero values.  linear stresses on tires 15-17. the bridge. The forward current is cut off by diode 5. For the stated reason, the pulses at the output of bridge 4 can occur only when the switching points in the converter coincide with the luminescence times of the corresponding LEDs in bridge 8. This bridge is powered by a generator of synchronizing pulses that appear in transition points line 0 five 0 five voltage of the mains through zero, i.e. at the points corresponding to the angles p of the advance of the inverter, equal to zero. Thus, the pulses at the input of the amplifier 6 pulses in the TC only if the switching of the converter occurs at (3 0, i.e. when the inverter starts to overturn. The driver 6 performs the functions of a normalizing converter, i.e. it amplifies the pulses to the desired amplitude in voltage and current.Resistor 9 serves to load the LEDs with current corresponding to their normal luminescence. The proposed device is much simpler known, since it does not contain current sensors in the converter phases and includes significantly fewer elements. Apparatus of the Invention A device for diagnosing disturbances of an inverter mode of a converter equipped with a three-phase power transformer connected between the terminals of an alternating current network and the corresponding outputs of an alternating current of the converter bridge, containing a three-phase generator of pulses synchronized with moments of linear voltage of an alternating current through zero value, differing from that, in order to simplify. an auxiliary three-phase transformer, six optocouplers, a resistor, a diode and a pulse amplifier are introduced, while the LEDs and photodiodes of the optocouplers form LED and photodiode bridges, respectively, the primary winding of the auxiliary transformer is connected in parallel to the primary winding of the power transformer, the secondary winding is intended to be connected by ends to kong The secondary winding of the power transformer is connected to the AC input of the photodiode bridge, the output of which is connected via a diode to the input of a pulse amplifier, the output of which is used as an output of the device, the AC bridge outputs connected to the output of a three-phase pulse generator, and the outputs The current is connected to a resistor. / J ABOUT 7 and 77 16 G5 17 16 Editor N. Kishtulinets Order 1401/51 VNIIPI USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, ul. Project, 4 FIG. g Compiled by V. Shirokov Tehred I. VeresKorrektor S. Cherni Circulation 619 Subscription