SU826489A1

SU826489A1 - Transistorized converter protection method

Info

Publication number: SU826489A1
Application number: SU792742110A
Authority: SU
Inventors: Александр Сергеевич Мазнев; Борис Юрьевич Левитский; Геннадий Кирилович Колычев; Алексей Петрович Зеленченко
Original assignee: Le I Inzhenerov Zheleznodorozh
Priority date: 1979-03-28
Filing date: 1979-03-28
Publication date: 1981-04-30

Description

Изобретение относится к силовой полупроводниковой технике и может быть использовано в многодвигательном приводе, например электропоездов постоянного тока.The invention relates to power semiconductor technology and can be used in a multi-motor drive, for example, direct current trains.

Известен способ защиты тиристорных преобразователей, при котором контролируют момент ® окончания коммутации вентилей, формируют контрольный импульс и в случае, если время выключения вентилей меньше заданного, подают сигнал на исполнительный орган защиты [1].There is a known method of protecting thyristor converters, in which the moment ® the end of switching valves is controlled, a control pulse is generated, and if the time for turning off the valves is less than the set value, a signal is sent to the protection executive body [1].

Наиболее близким по технической сущности ^{10 * * * *} и достигаемым результатам к изобретению является способ защиты тиристорного преобразователя, при котором контролируют величину и знак скорости изменения выходного тока и при заданном их значении воздействуют на ¹⁵ управление тиристорами преобразователя [2].The closest in technical essence ^{10 * * * *} and the achieved results to the invention is a method for protecting a thyristor converter, in which the magnitude and sign of the rate of change of the output current is controlled and, at a given value, they affect ¹⁵ control of the thyristors of the converter [2].

Недостатком указанных способов является низкая чувствительность зашиты, обуславливающая невозможность определения и локализации аварийных процессов в начальной стадии их развития.The disadvantage of these methods is the low sensitivity of the protection, making it impossible to identify and localize emergency processes in the initial stage of their development.

Цель изобретения — повышение надежности работы преобразователя.The purpose of the invention is to increase the reliability of the Converter.

Поставленная цель достигается тем, что дополнительно определяют скорость изменения напряжения на выходе преобразователя и, в зависимости от отклонения последней от заданного значения, корректируют задающее значение величины выходного тока и одновременно изменяют частоту определения скорости изменения напряжения.This goal is achieved by the fact that they additionally determine the rate of change of voltage at the output of the converter and, depending on the deviation of the latter from the set value, adjust the set value of the output current and simultaneously change the frequency of determining the rate of change of voltage.

На фиг. 1 изображена принципиальная схема устройства, реализующего предлагаемый способ; на фиг. 2 диаграммы, поясняющие принцип действия устройства.In FIG. 1 shows a schematic diagram of a device that implements the proposed method; in FIG. 2 diagrams explaining the principle of the device.

Устройство, реализующее предлагаемый способ, содержит тиристорный импульсный преобразователь ’ 1, включенный между положительным полюсом источника 2 питания и катодом шунтирующего диода 3, анод которого присоединен к отрицательному полюсу источника 2 питания. Между катодом шунтирующего диода 3 и якорем первого тягового двигателя 4 включен датчик 5 тока якоря. Последовательно с якорем тягового двигателя 4 соединен якорь тягового двигателя 6, последовательно к которому присоединено начало последовательно соединенных обмоток 7 и 8 возбуждения, конец которых присоединен к отрицательному полюсу источника 2 питания. К катоду диода 3 присоединен резистор 9, последовательно с которым соединен резистор 10, другой конец которого присоединен к началу обмотки 7 возбуждения. К точкам соединения якорей тяговых двигателей 4 и 6 и шунтирующим их резисторам 9 и 10 подключен блок 11 сравнения. Блок 11 сравнения включает в себя два выпрямительных моста 12 и 13 с емкостными фильтрами.A device that implements the proposed method contains a thyristor pulse converter ’1 connected between the positive pole of the power supply 2 and the cathode of the shunt diode 3, the anode of which is connected to the negative pole of the power supply 2. An armature current sensor 5 is connected between the cathode of the shunt diode 3 and the armature of the first traction motor 4. In series with the anchor of the traction motor 4, an anchor of the traction motor 6 is connected, in series to which the beginning of the series-connected excitation windings 7 and 8 is connected, the end of which is connected to the negative pole of the power supply 2. A resistor 9 is connected to the cathode of the diode 3, in series with which a resistor 10 is connected, the other end of which is connected to the beginning of the field winding 7. To the connection points of the anchors of the traction motors 4 and 6 and the resistors 9 and 10 shunting them, a comparison unit 11 is connected. Block 11 comparison includes two rectifier bridge 12 and 13 with capacitive filters.

Входы выпрямительных мостов 12 и 13 соединены между собой и присоединены к средним точкам между якорями тяговых двигателей 4 и 6 и шунтирующими резисторами 9 и 10. Положительные зажимы выпрямительных мостов 12 и 13 соединены с тиристорными ключами 14 и 15. К выходам тиристорных ключей 14 и 15 подключены одним контактом резисторы 16 и 17 и верхние обкладки конденсаторов 18 и 19 соответственно. Другой контакт резисторов 16 и 17 соединен с анодом тиристоров 20 и 21 соответственно. Катоды тиристоров 20 и 21, нижние обкладки конденсаторов 18 и 19 соединены между собой и присоединены к отрицательным выходам выпрямительных мостов 12 и 13. Между выходом тиристорного ключа 15 и включенными встречно-параллельно тиристорами 22 и 23 включен орган 24 сравнения (компаратор). Входные цепи тиристоров устройства 11 сравнения соединены с выходами кольцевого регистра 25 сдвига. Вход кольцевого регистра 25 сдвига присоединен к выходу блока 26 управления тиристорного преобразователя 1. Другой выход блока 26 управления присоединен к входным цепям тиристорного преобразователя 1. Вход блока 26 управления соединен с блоком 27 коррекции уставки тока якоря. К входам блока 27 коррекции уставки соединен выход датчика 5 тока и блок 28 измерения скорости изменения напряжения в диагонале моста.The inputs of the rectifier bridges 12 and 13 are interconnected and connected to the midpoints between the anchors of the traction motors 4 and 6 and the shunt resistors 9 and 10. The positive terminals of the rectifier bridges 12 and 13 are connected to the thyristor switches 14 and 15. To the outputs of the thyristor switches 14 and 15 resistors 16 and 17 and the upper plates of capacitors 18 and 19, respectively, are connected by one contact. Another contact of the resistors 16 and 17 is connected to the anode of the thyristors 20 and 21, respectively. The cathodes of the thyristors 20 and 21, the lower plates of the capacitors 18 and 19 are interconnected and connected to the negative outputs of the rectifier bridges 12 and 13. Between the output of the thyristor switch 15 and the on-off thyristors 22 and 23, a comparison organ 24 (comparator) is turned on. The input circuits of the thyristors of the comparison device 11 are connected to the outputs of the annular shift register 25. The input of the ring shift register 25 is connected to the output of the control unit 26 of the thyristor converter 1. The other output of the control unit 26 is connected to the input circuits of the thyristor converter 1. The input of the control unit 26 is connected to the armature current setpoint correction unit 27. To the inputs of the setpoint correction unit 27, the output of the current sensor 5 and the unit 28 for measuring the rate of change of voltage in the diagonal of the bridge are connected.

В нормальном режиме работы между точками а и б возникает напряжение небаланса, обусловленное расхождением электромеханических характеристик тяговых двигателей и диаметров бандажей колесных пар, которое устанавливается на выходах выпрямительных мостов. После отпирания тиристорного ключа 14, а затем тиристорного ключа 15 импульсами, следующими с блока 25, конденсаторы 18 и 19 заряжаютЬя до указанного напряжения. Далее следуют управляющие импульсы с блока 25 на тиристоры 22 и 23, однако вследствие равенства напряжений на конденсаторах 18 и 19, тиристоры 22 и 23 не отпираются, а орган 24 сравнения не вырабатывает сигнала на выходе. Затем следуют импульсы управления с блока 25 на тиристоры 20 и 21. Тиристоры 20 и 21 отпираются и через резисторы 16 и 17 происходит разряд конденсаторов 18 и 19, т.е. система возвращается в исходное состояние.In normal operation between points a and b, an unbalance voltage occurs due to the discrepancy between the electromechanical characteristics of the traction motors and the diameters of the wheelset bandages, which is installed at the outputs of the rectifier bridges. After unlocking the thyristor key 14, and then the thyristor key 15 pulses following from block 25, the capacitors 18 and 19 charge up to the specified voltage. Next, the control pulses from block 25 to the thyristors 22 and 23 follow, however, due to the equality of voltages across the capacitors 18 and 19, the thyristors 22 and 23 do not unlock, and the comparison body 24 does not generate an output signal. Then, control pulses follow from block 25 to thyristors 20 and 21. Thyristors 20 and 21 are unlocked and capacitors 18 and 19 discharge through resistors 16 and 17, i.e. the system returns to its original state.

Пуск в этом случае осуществляется при токе, равном (ток уставки). Контроль величины и знака скорости изменения выходного тока якоря осуществляется датчиком 5 тока якоря и блоком 27.Start in this case is carried out at a current equal to (set current). The magnitude and sign of the rate of change of the output current of the armature is controlled by the sensor 5 of the armature current and block 27.

В случае развития процесса боксования или юза, например, двигателя 4 после отпирания тиристорного ключа 14, а затем тиристорного ключа 15, импульсами и следующими с блока 25 с частотой £ ₁ (фиг. 2), ₁₅ заряжаются конденсаторы 18 и 19. Причем величина напряжения конденсатора 18 будет меньше, чем напряжение на конденсаторе 19, так как за время д £ напряжение П_{а 9} между точками а и б возрастет на величи₂₀ ну aV _s При подаче сигналов управления на тиристоры 22 и 23 отопрется тиристор 23 и на выходе органа 24 сравнения появляется сигнал.In the case of the development of the boxing process or the use of, for example, the motor 4 after unlocking the thyristor key 14, and then the thyristor key 15, pulses and the following from block 25 with a frequency of £ ₁ (Fig. 2), ₁₅ are charged capacitors 18 and 19. Moreover, the voltage value of the capacitor 18 will be less than the voltage across the capacitor 19, since during the time d £ the voltage Pa ₉ between points a and b will increase by ₂₀ well aV _s When the control signals are applied to thyristors 22 and 23, the thyristor 23 will heat up and at the output of the organ 24 comparison signal appears.

Далее блок 28 измеряет скорость изменения ₂₅ тока в цепи тяговых двигателей 4 и 6, которая пропорциональна скорости изменения напряжения в точках а и б.Next, block 28 measures the rate of change of ₂₅ current in the circuit of traction motors 4 and 6, which is proportional to the rate of change of voltage at points a and b.

в(а^ dJin (a ^ dJ

- “3FT’ где □ — ток в цепи тяговых двигателей.- “3FT’ where □ is the current in the traction motor circuit.

Затем блок 28 выдает сигнал на блок 27 коррекций уставки. Блок 27 коррекции уставки выдает сигнал на изменение коэффициента заполнения и частоты следования импульсов ³⁵ на блок 25 в функции величины производной выходного тока.Then block 28 provides a signal to block 27 correction settings. The setpoint correction unit 27 gives a signal to change the duty cycle and pulse repetition rate of ³⁵ to block 25 as a function of the derivative of the output current.

Например, при малой скорости развития ₄₀ боксования частота считывания f также понижается до значения f . При большой скорости развития боксования частота считывания £ повышается до значения f₃>f₄.For example, at a low rate of development of ₄₀ boxing, the reading frequency f also decreases to a value f. With a high speed of boxing development, the readout frequency £ rises to the value f ₃ > f ₄ .

Одновременно регулируется коэффициент заполнения λ:At the same time, the duty cycle λ is adjusted:

Техник©-экономическим преимуществом предлагаемого способа защиты является повы⁵⁰ шение надежности и чувствительности защиты преобразователя.Technician © -economic advantage of the proposed method of protection is ⁵⁰ povy shenie reliability and sensitivity of the transducer protection.

Claims

The invention relates to power semiconductor technology and can be used in a multi-motor drive, for example, direct current electric trains. A known method of protecting thyristor converters, in which they control the end of valve switching, form a control pulse and, if the valve shutdown time is less than the specified time, send a signal to the protection actuator 1. The closest to the technical essence and the achieved results to the invention is a thyristor converter, at which the magnitude and sign of the rate of change of the output current is controlled and, for a given value, affect the control of the thyristors Operator 2. The disadvantage of these methods is the low sensitivity of the protection, which makes it impossible for x to limit and localize the emergency processes at the initial stage of their development. The purpose of the invention is to increase the reliability of the converter. This goal is achieved by additionally determining the rate of change of current at the output of the converter and, depending on the deviation of the latter from the specified value, corrects the setting value of the output current and simultaneously changes the frequency of determining the rate of change of voltage. FIG. 1 is a schematic diagram of a device implementing the proposed method; in fig. 2 are diagrams explaining the operation of the device. A device implementing the proposed method contains a thyristor pulse converter 1 connected between the positive pole of the power supply 2 and the cathode of the bypass diode 3, the anode of which is connected to the negative pole of the power supply 2. Between the cathode of the bypass diode 3 and the first motor motor 4, the sensor 5 of the current cor. In series with the core of the engine 4, the core of the engine 6 is connected, in series with which is connected the beginning of the series-connected excitation windings 7 and 8, the end of which is connected to the negative pole of the power supply 2. A resistor 9 is connected to the cathode of diode 3, in series with which resistor 10 is connected, the other end of which is connected to the beginning of excitation winding 7. The points of connection of Korean traction engines 4 and 6 and the shunt of their resistors {9 and 10 are connected. Comparison unit 11 Comparison unit 11 includes two rectifying bridges 12 and 13 with capacitive filters. The inputs of the rectifier bridges 12 and 13 are interconnected and connected to the middle points between the cords of the traction motors 4 and 6 and the shunting resistors 9 and 10. The positive terminals of the rectifying bridges 12 and 13 are connected to the thyristor switches 14 and 15. To the outputs thyristor switches 14 and 15 are connected by one contact resistors 16 and 17 and the upper plates of capacitors 18 and 19, respectively. The other contact of the resistors 16 and 17 is connected to the anode of the thyristors 20 and 21, respectively. Thyristor cathodes 20 and 21, the lower plates of capacitors 18 and 19 are interconnected and connected to the negative outputs of the rectifying bridges 12 and 13. Between the output of the thyristor switch 15 and the thyristors 22 and 23 turned in opposite direction, the comparator 24 is switched on (comparator). The input circuits of the thyristors of the comparator device 11 are connected to the outputs of the ring shift register 25. The input of the annular register 25 shift is connected to the output of the control unit 26 of the thyristor converter 1. Another output of the control unit 26 is connected to the input circuits of the thyristor converter 1. The input of the control unit 26 is connected to the block 27 KoppeKHjiH of the current setting box. To the inputs of the setpoint correction unit 27, the output of the current sensor 5 and the unit 28 for measuring the rate of change of voltage 1 in the bridge diagonal are connected. In normal operation, between points a and b, an unbalance tension arises due to the discrepancy between the electromechanical characteristics of the traction engines and the diameters of the wheelset bandages, which is installed at the outlets of the powerful bridges. After unlocking the thyristor switch 14 and then the thyristor switch 15 with pulses following from block 25, the capacitors 18 and 19 are charged to the internal voltage. Next, control pulses from block 25 to thyristors 22 and 23 follow, however, due to the equality of the capacitors 18 and 19, the thyristor 22 and 23 are not unlocked, and the comparator 24 does not produce an output signal. Then, control pulses 1 4 of block 25 follow to thyristors 20 and 21. Thyristors 0 and 21 are unlocked and capacitors 18 and 19 discharge through resistors 16 and 17, i.e. The system returns to its original state. The acceleration in this case is effected at avn,.,. (current setting). The control of the magnitude and sign of the rate of change in the output current of the core box is determined by the sensor 5 of the core current and block 27. In the event of a blocking process or a skid, for example, a motor 4, after unlocking the thyristor switch 14, and then the thyristor switch 15, pulses U. and those from block 25 with frequency f (Fig. 2), capacitors 18 and 19 are charged. Moreover, the top of the capacitor 18 will be less than the voltage on the capacitor 19, since the voltage across and between the points a and b will increase by the value of aV s When control signals are applied to thyristors 2 2 and 23, a thyristor 23 is emitted and a signal appears at the output of the organ 24 of equilibrium. Next, block 28 measures the rate of change of current in the chain of traction motors 4 and 6, which is proportional to the rate of change of voltage at points a and b. cKy) 33 AG where D is the current in the motor circuit. Then, unit 28 outputs a signal to setpoint correction unit 27. The setpoint correction unit 27 outputs a signal for a change in the filling ratio {t and the following pulses on block 25 in the function of the output current derivative. For example, at a low rate of development of the boxing, the reading frequency f also decreases to a value of 5 ,. With a high rate of development of boxing --- the frequency of reading tR rises to the value. At the same time, the fill factor I: is adjusted. BC) The feasibility of the proposed protection method is to increase the reliability and sensitivity of the protection of the converter. Claim method The protection of a thyristor converter, in which the magnitude and sign of the rate of change of the output current is controlled and at 5 given values affect the control of the thyristors of the converter, characterized in that, in order to increase the reliability of the converter, the rate of voltage variation at the converter output and, depending on the deviation of the latter from the predetermined value, corrects the setting value of the output current and simultaneously change the frequency of determining the speed growth voltage. Sources of information taken into account in the examination 1. The author's certificate of the USSR N 536564, cl. H 02 H 7/10, 1975.

2. USSR author's certificate number 530388, cl. H 02 H 7/10, 1974.

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