SU1271772A1

SU1271772A1 - Traction electric drive of single-phase alternating current rolling stock

Info

Publication number: SU1271772A1
Application number: SU853878488A
Authority: SU
Inventors: Николай Степанович Назаров; Иван Георгиевич Семкин
Original assignee: Омский Институт Инженеров Железнодорожного Транспорта
Priority date: 1985-04-02
Filing date: 1985-04-02
Publication date: 1986-11-23

Description

Изобретение относится к транспорту, в частности к электроприводам подвижного состава однофазного переменного тока.The invention relates to transport, in particular to electric drives of a rolling stock of single-phase alternating current.

Цель изобретения - повышение экономичности.The purpose of the invention is improving efficiency.

На фиг.1 представлена принципиальная электрическая схема предлагаемого электропривода; на фиг.2 временные диаграммы токов и напряжений в элементах'электропривода,поясняющие его работу.Figure 1 presents a circuit diagram of the proposed electric drive; in Fig.2 time diagrams of currents and voltages in the elements of the electric drive, explaining its operation.

Тяговый электропривод (фиг.1) содержит тяговые электродвигатели 1, подключенные к одним выводам мостового’ тиристорного преобразователя, выполненного на тиристорах 2-7,.другие выводы которого соединены с секциями 8 и 9 вторичной обмотки тягового трансформатора 10. Первичная обмотка 11.тягового трансформатора подключена к источнику 12 переменного однофазного тока. Мостовой тиристорный преобразователь включает коммутирующий конденсатор 13, соединенный одной обкладкой с секциями 8 и 9 вторичной обмотки тягового трансформатора 10, а другой - с коммутирующими тиристорами 14 и 15, и дополнительными тиристорами 16 и 17, включенными параллельно и встречно тиристорам 6 и 7.The traction electric drive (Fig. 1) contains traction motors 1 connected to one terminal of a bridge 'thyristor converter made on thyristors 2-7, the other terminals of which are connected to sections 8 and 9 of the secondary winding of the traction transformer 10. The primary winding 11. of the traction transformer connected to a source of 12 alternating single-phase current. The bridge thyristor converter includes a switching capacitor 13, connected by one plate to sections 8 and 9 of the secondary winding of the traction transformer 10, and the other with switching thyristors 14 and 15, and additional thyristors 16 and 17 connected in parallel and opposite to thyristors 6 and 7.

На временных диаграммах (фиг.2) представлены кривые а и S’ - напряжение и ток первичной обмотки 11 тягового трансформатора, кривые Ь и Z - токи секций 8 и 9 вторичной обмотки тягового трансформатора,кривые и е - напряжение и ток коммутирующего конденсатора 13, кривые Ж - токикоммутирующих тиристоров 14, 15, кривые - токи дополнительных тиристоров 16 и 17.On the time diagrams (figure 2) curves a and S 'are the voltage and current of the primary winding 11 of the traction transformer, curves b and Z are the currents of sections 8 and 9 of the secondary winding of the traction transformer, curves and e are the voltage and current of the switching capacitor 13, curves G - current switching thyristors 14, 15, curves - currents of additional thyristors 16 and 17.

'Тяговый электропривод работает следующим образом.'Traction drive operates as follows.

Регулирование величины выпрямленного напряжения осуществляется зонно-фазовым способом. В конце каждого полупериода на любой зоне происходит искусственная коммутация токов секций 8 и 9 силового трансформатора 10. Для рассматриваемого полупериода питающего напряжения направление ЭДС в секциях 8 и 9 вторичной обмотки трансформатора (соответственно 1₈ . и 1₉), а также полярность заряда конденсатора 13 показаны на фиг.1. До момента t₍ (фиг.2) электро двигатели 1 подключены к секции 9, так как открыты тиристоры 4 и 7.ТоК электродвигателей 1 проходит по цепи: тиристор 4 - секция 9 - тиристор 7 - электродвигатели 1. В момент t₍ отпирается тиристор 2, что приводит к выключению тиристора 4 в момент t₂. В результате электродвигатели 1 подключены к всей вторичной обмотке, т.е. образуется цепь: тиристор 2 - секции 8 и 9 тиристор 7 - электродвигатели 1.The regulation of the rectified voltage is carried out by the zone-phase method. At the end of each half-cycle in any zone, the currents of sections 8 and 9 of the power transformer 10 are artificially switched. For the considered half-period of the supply voltage, the direction of the EMF in sections 8 and 9 of the secondary winding of the transformer (respectively 1 _8. And 1 ₉ ), as well as the charge polarity of the capacitor 13 shown in figure 1. Until time t ₍ (Fig. 2), electric motors 1 are connected to section 9, since thyristors 4 and 7 are open. Current of electric motors 1 passes through the circuit: thyristor 4 - section 9 - thyristor 7 - electric motors 1. At time t _(the thyristor is opened 2, which leads to the thyristor 4 turning off at the time t _2. As a result, the electric motors 1 are connected to the entire secondary winding, i.e., a circuit is formed: thyristor 2 - sections 8 and 9, thyristor 7 - electric motors 1.

В момент t₃ , опережающий угол К на величину четверти периода частоты собственных колебаний контура конденсатор 13 - секция 9, начинается процесс искусственной коммутации тока в секции 9. Для этого подаются управляющие импульсы на тиристоры 15 и 17, начинается перезаряд конденсатора 13 по цепи: тиристор' 15 - тиристор 7 - секция 9 'конденсатор 13. В момент t₉ величина тока конденсатора (фиг.2 кривая 1) достигает значения тока электродвигателя 1, в результате чего тиристор 7 закрывается, а тиристор 17 - открывается. Ток электродвигателей идет по цепи:: тиристор 2 секция 8 - конденсатор 13 - тиристор 15 - электродвигатели 1. С момента t₄ мгновенное значение тока конденсатора 10 больше, т.е. тока электродвигателей 1. Этим обуславливается импульс тока обратной полярности (по отношению к току с секции 8) обмотке трансформатора 10 (фиг.2).At time t ₃ , the angle K is ahead of the value of a quarter of the period of the natural oscillations of the circuit by the capacitor 13 - section 9, the process of artificial switching of the current begins in section 9. For this, control pulses are applied to thyristors 15 and 17, and the capacitor 13 is recharged along the circuit: thyristor '15 - thyristor 7 - section 9' capacitor 13. At time t _{9, the} current value of the capacitor (figure 2 curve 1) reaches the current value of the electric motor 1, as a result of which the thyristor 7 closes, and the thyristor 17 opens. The current of the electric motors goes through the circuit :: thyristor 2 section 8 - capacitor 13 - thyristor 15 - electric motors 1. From moment t _{4 the} instantaneous value of the current of the capacitor 10 is greater, i.e. current of electric motors 1. This determines the current pulse of reverse polarity (with respect to the current from section 8) of the transformer winding 10 (figure 2).

В момент t₅ снова ток-конденсатора равен току электродвигателей, а в тиристоре 17 становится равным нулю, в результате чего тиристор 17 закрывается и конденсатор 10 отключается от секции 9 обмотки. Однако заряд конденсатора не прекращается так, как через него продолжает идти ток электродвигателей 1 по цепи, указанной для интервалаAt time t ₅ , the current capacitor again is equal to the current of the electric motors, and in the thyristor 17 it becomes equal to zero, as a result of which the thyristor 17 closes and the capacitor 10 is disconnected from the winding section 9. However, the capacitor charge does not stop as the current of electric motors 1 continues to flow through it along the circuit indicated for the interval

В момент t₆ напряжение конденсатора 10 достигает максимально допустимой величины, которая определяется из условия: напряжение на конденсаторе не должно превышать такой величины, приложение которой к секции 9 в момент начала искусственной коммутации вызывает превышение амплитудного значения напряжения секции 9. Для предотвращения дальнейшего заряда конденсатора в этот момент открываются тиристоры 5 и 6, ток электродвигателей 1 из цепи: тиристор 2 - секция 8 - Конденсатор 13 тиристор 15 - коммутирует в цепь: тиристор 6 - секция 9 - тиристор 5 - 5 электродвигатели 1. Ускоренному прохождению этой коммутации способствует и то, что напряжение, приложенное к коммутируемым тиристорам, определяется суммой напряжений на сек- Ю циях трансформатора и конденсатора.At time t _{6, the} voltage of the capacitor 10 reaches the maximum allowable value, which is determined from the condition: the voltage on the capacitor should not exceed such a value that applying it to section 9 at the time of the start of artificial switching causes the amplitude of the voltage of section 9 to be exceeded. this moment opens thyristors 5 and 6, the current of electric motors 1 from the circuit: thyristor 2 - section 8 - Capacitor 13 thyristor 15 - switches to the circuit: thyristor 6 - section 9 - thyristor 5 - 5 electric Parents 1. Accelerated passage of this switching is also facilitated by the fact that the voltage applied to the switched thyristors is determined by the sum of the voltages in the transformer and capacitor sections.

В следующем полупериоде питающего напряжения в схеме происходят аналогичные электромагнитные процессы. В момент отпирается тиристор 3, что приводит к выключению тиристора 5 в момент t_g, электродвигатели 1 подключены к всей вторичной обмотке трансформатора. В момент t₉, отстоящий от ΐ на величину четверти периода частоты собственных колебаний контура конденсатор 13 - секция 9, начинается искусственная коммутация тока в секции 9, для чего откры- 25 вается тиристор 14, а в момент t₎₀ тиристор 16. В интервале t₁₀ -t_1f направление тока в секции 9 противоположно току в секции 8, т.е. имеет место импульс тока обратной поляр- ₃₀ности. В момент t_H выключается тиристор 16, а в момент t_1z>xorfla напряжение конденсатора 13 достигает максимально допустимой величины, открываются тиристоры 4. и 7 и процесс заряда конденсатора прекращается.In the next half-cycle of the supply voltage, similar electromagnetic processes occur in the circuit. At the moment, the thyristor 3 is unlocked, which leads to the turn off of the thyristor 5 at the moment t _g , the electric motors 1 are connected to the entire secondary winding of the transformer. At time t ₉ , which is четвер apart from ΐ by a quarter of the period of the natural frequency of the oscillation of the circuit, capacitor 13 is section 9, artificial switching of the current begins in section 9, for which thyristor 14 opens, and at time t _{) 0} thyristor 16. In the interval t ₁₀ -t _{1f the} direction of the current in section 9 is opposite to the current in section 8, i.e. It holds reverse polarity pulse ₃₀ NOSTA current. At time t _H, thyristor 16 turns off, and at time t _1z> xorfla, the voltage of capacitor 13 reaches the maximum allowable value, thyristors 4. and 7 open, and the process of charging the capacitor stops.

Таким образом, предлагаемая схема позволяет регулировать длительность ₄₀прохождения тока перезаряда конден сатора за счет изменения момента отпирания очередных тиристоров 4-7. Этим обеспечивается возможность управления величиной напряжения конденсатора, поскольку напряжение и ток конденсатора связаны соотношеdUc ни ем 1_с = -С где с - величина емкости конденсатора.Thus, the proposed circuit makes it possible to control the duration _{40 of the} passage of the capacitor overcharge current due to a change in the instant of unlocking of the next thyristors 4–7. This makes it possible to control the value of the capacitor voltage, since the voltage and current of the capacitor are connected by the ratio dUc of 1 _s = -C where c is the value of the capacitor capacitance.

Claims

The invention relates to a transport, in particular to electric drives of a rolling stock of single-phase alternating current. The purpose of the invention is to increase economy. Figure 1 shows the circuit diagram of the proposed electric drive; Fig. 2 are time diagrams of currents and voltages in the elements of an electric drive, relating to its operation. The traction motor (fig) contains traction motors 1 connected to one terminals of a bridge thyristor transducer, made on thyristors 2-7, the other terminals of which are connected to sections 8 and 9 of the secondary winding of the transformer 10. Primary coil 11.t a hv transformer is connected to a source 12 of alternating single-phase current. The bridge thyristor converter includes a commutation capacitor 13. connected by one plate with sections 8 and 9 of the secondary winding of the transformer 10, and the other with commutating thyristors 14 and 15, and additional thyristors 16 and 17 connected in parallel and all. the triacs of thyristors 6 and 7. On the time diagrams (Fig. 2), curves a and 5 ° are the voltage and current of the primary winding of the 11th transformer, curves 6 and 1 are the currents of sections 8 and 9 of the secondary winding of the transformer, high and e - voltage and current commuting to ndensatora 13, curves x - tokikommutiruyuschih tiristo moat 14, 15, curves - currents additional thyristors 16 and 17. Traction drive operates as follows, the values of regulation of the rectified voltage Nogo is performed zone-phase method. At the end of each half-period, an artificial switching of the current sections 8 and 9 of the power transformer 10 occurs in any zone. For the considered half-period of the supply voltage, the EMF direction in sections 8 and 9 of the secondary winding of the transformer (respectively Ig. And 19) as well as polarity The charge of the capacitor 13 is shown in FIG. Up to the moment t ((Fig.2) electr motors 1 are connected to section 9, since thyristors 4 and 7 are open. Electric motors 1 pass through the circuit: thyristor 4 - section 9 - thyristor 7 - electric motors 1. At time t, the thyristor is unlocked 2, which causes the thyristor 4 to be turned off at time tj. As a result, the electric motors 1 are connected to the entire secondary winding, i.e. a circuit is formed, the thyristor 2 - sections 8 and 9, the thyristor 7 - electric motors 1. leading UGOL At time t. the value of a quarter of the period of the proper oscillations of the circuit, the capacitor 13 - section 9, begins n An artificial current switching process in section 9. To do this, control pulses are applied to thyristors 15 and 17, the recharging of capacitor 13 across the circuit begins: thyristor 15 - thyristor 7 - section 9 capacitor 13. At time t4, the current value of the capacitor (Fig. 2 curve 1) reaches the value of the current of the electric motor 1, as a result of which the thyristor 7 is closed and the thyristor 17 opens. The current of the electric motors goes along the circuit;: thyristor 2 section 8 - capacitor 13 - thyristor 15 - electric motors 1. From the instant tjj more, i.e. current of electric motors 1. This causes a current pulse of reverse polarity (relative to the current from section 8) to the winding of the transformer 10 (Fig. 2). At time t, the current-capacitor is again equal to the current of the electric motors, and in the thyristor 17 becomes equal to zero, with the result that the thyristor 17 is closed and the capacitor 10 is disconnected from the winding section 9. However, the charge of the capacitor does not stop as it continues through and the current of the electric motors 1 along the circuit specified for the interval. At time tg, the voltage of the capacitor 10 reaches the maximum allowable value, which is determined from the condition J on the capacitor should not exceed such a value, the application of which to section 9 at the time of the start of artificial switching causes the amplitude value of the voltage of section 9 to be exceeded. further charging of the capacitor at this moment the thyristors 5 and 6 are opened, the current of the electric motors 1 from the circuit: thyristor 2 - section 8 - Capacitor 13 thyristor 15 - commutes to the circuit: thyristor 6 - section 9 - thyristor 5 elec Rotor motors 1. The acceleration of this switching is also facilitated by the fact that the voltage applied to the switching thyristors is determined by the sum of the voltages on the transformer and capacitor sections. In the next half-period of the supply voltage, analogous electromagnetic processes occur in the circuit. At time tj, the thyristor 3 is opened, which causes the thyristor 5 to be turned off at time tg, the electric motors 1 are connected to the entire secondary winding of the transformer. At time t, the distance between f and f: value of a quarter of the period of the natural oscillation frequency of the circuit, capacitor 13 - section 9 begins the artificial switching of current in section 9, for which the thyristor 14 opens, and at time t, (j thyristor 16, In the interval -t The direction of the current in section 9 is opposite to the current in section 8, i.e. a reverse current pulse takes place. At time t, the thyristor 16 is turned off, and at time t, 2j the capacitor 13 voltage reaches the maximum allowed values, thyristors 4. and 7 are opened and the capacitor charging process is terminated Thus, the proposed scheme allows adjusting the duration of the passage of the recharge current of the capacitor 724 by changing the time of unlocking the next thyristors 4-7. This provides the ability to control the value of the capacitor voltage, because the voltage and current of the capacitor are related to where The i-C dt. capacitor capacitance. Formula of the Invention The traction electric drive of the rolling stock of a single-phase alternating current, containing the traction motors connected to one bridge About the thyristor converter, to the other terminals of which are connected one and the other in series connected sections of the secondary winding of a transformer connected by the primary winding to a contact network, switching thyristors and a capacitor, differing in that, in order to increase efficiency, it is equipped with additional thyristors connected the counter thyristor of the converter connected to one of the sections of the secondary winding of the traction transformer, while the switching capacitor is connected to one plate It is connected to the connection point of one and the other sections of the secondary winding of the transformer, and the other lining to the connection point in series and according to the switched on switching thyristors connected by other electrodes to one pins of the bridge thyristor converter.