SU1672546A1 - M-phase inverter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in converter devices with artificial switching of power thyristors. The aim of the invention is to increase the efficiency of the device and improve its operational characteristics. The device contains an M-phase bridge of power thyristors 1-6 with non-return valves 7-12. Two groups of distribution thyristors 13-18 are connected to two storage capacitors 19, 20 through two switching keys based on fully controlled thyristors 21, 22 and two groups of M diodes 25 - 30. In the device, dos-a storage capacitors take place due to the energy accumulated in the load inductance. 2 Il.

Description

The invention relates to electrical engineering and may find application in converters of a wide purpose with artificial switching of thyristors.

The aim of the invention is to improve the economy and improve performance.

FIG. 1 shows the basic electrical circuit of the power unit of the t-phase inverter;

in fig. 2, the following designations are given: Tch-Te are the intervals of the on state of power thyristors;

UAB (AC.BC) - linear voltages;

UK - interference generated by the switching node of the prototype device;

11uk - interference generated by the switching node of the proposed device.

The inverter contains an m-phase power thyristor bridge 1-6 with non-return valves, thyristors 7-12, two groups of distribution thyristors 13-18, two storage capacitors 19 and 20, two fully controllable switches made on the basis of lockable thyristors 21 and 22, two sources of recharging 23, 24 storage capacitors and two groups of 25-30 m diodes.

The inverter works as follows. The algorithm of the inverter and the processes in it are considered on the example of a three-phase voltage inverter. The unlocking of power thyristors occurs under the influence of control pulses in the sequence 1-5-3-4-2-6 with an interval of 60 eh grades.

The conduction interval of the shoulder of the bridge consists of the conduction interval of the power

About vj GO SL About

thyristor and switching interval. The length of the on state of a power thyristor may vary.

Oht

where tvs is the duration of the on state of the thyristor;

Tm is the modulation period;

U switching interval,

The inverter operation algorithms are provided with rectangular linear voltage pulses and a linear current curve that is close to a sinusoidal curve. In the interval with ideal switches, in any intercommutational interval, the current is conducted by two keys in one group and one in the other. In an inverter with thyristors, it is necessary to take into account the switching intervals and the preparation intervals of the switching capacitors for the next switching, otherwise the inverter will not work. For example, thyristors 1.5 and 3 are current to time. Before thyristor 4 is turned on, thyristor 1 must be turned off. To do this, thyristor 21 and distribution thyristor 13 must be turned on at time ti. : capacitor 19, thyristor 21, separator thyristor 13, power thyristor 1, capacitor 19. A blocking voltage equal to the voltage across the capacitor 19 is applied to the power thyristor, and the current goes to the circuit capacitor 19 thyristor 21, separator A thyristor 13 minutes When the time sufficient for accurate reduction locking properties power thyristor 21 of thyristor 1 is closed. Since the load has inductance, self-induction EMF tends to keep the load current unchanged in circuit A, B, power thyristor b, capacitor 20, diode 25 A. According to the current to the storage capacitor 20, the current is charging, so the capacitor 2-0 Charges with polarity plus on the bottom plate, minus - on the top. As current flows, the voltage across capacitor 20 increases. At the moment of equality of its specified value, the reverse current thyristor 10 (ta) opens and the load flows in the circuit: B, the reverse current thyristor 10, A. At time v, the next control pulse opens thyristor 4. At time ts, the switching locked thyristor 17 turns on and then the processes are repeated with the only difference that the daughter of the current of phase B will receive a capacitor 19

through a diode 29, and after its charge, a reverse current thyristor 8 will open. Dozar d of storage capacitors with a load current allows, firstly, to reduce the installed

the power of the dosage device of the storage capacitor, secondly, to increase the efficiency of the inverter due to the fact that the energy of the capacitor, expended to conduct the switching, is replenished for

the expense of energy stored in the load inductance, thirdly, to improve the operating characteristics of the inverter.

Claims (1)

Invention Formula An M-phase inverter, comprising an M-phase power thyristor bridge connected to the input terminals with non-return valves, two groups of distribution thyristors, each of which consists of hp thyristors, the cathodes of the distribution thyristors of the first group are connected to the cathodes of the corresponding power thyristors of the anode group, and the anodes are combined through the first according to the included, fully controlled thyristor and the first storage capacitor connected in series with the positive input terminal, the groups are connected to the anodes of the corresponding power thyristors of the cathode group, and the cathodes are combined and through the second one, according to the included, completely controlled thyristor and sequentially the second storage capacitor connected to it is connected to the negative input terminal, and the capacitors are connected to the terminals of the recharge sources made the charge opposite to i is the polarity of the terminals, about t and h a rein and so that, in order to increase efficiency and improve performance, it introduced two groups of diodes, the first of which consists of m-diodes connected the combined anodes to the junction point of the second fully controlled thyristor and the second storage capacitor, and the cathodes to the cathodes of the corresponding distribution thyristors of the PSORI group, with the t-diodes of the second group being combined by the cathodes connected to the toik of the connection of the first fully controlled a thyristor and a porous storage capacitor, and the anodes of these diodes are connected to the anodes of the respective distribution thyristors of the second group. tf Ј 72 / 3 V D V7 if 72 8} 7-3 & U