RU1800560C - Electric machine source of pulses - Google Patents

Abstract

Usage: electronics, electrical machine switching power supply, 2 Summary of the invention; The electric machine source of pulses contains two electric machines on one shaft: a synchronous generator and an asynchronous machine. The synchronous generator consists of a stator with a winding and a rotor of a synchronous generator; a direct current winding and a damper winding are located. The asynchronous machine has a stator with a 3-phase winding. The stator winding of an asynchronous machine has the number of PZ pole pairs. The stator winding of a synchronous generator has a number of pole pairs Pi less than Ra. The windings of the stators of the two machines are connected in parallel to each other and through the switching devices to the load. 2 ill.

Description

The invention relates to pulsed electrical machine power sources generating single and repetitive pulses, which are used, for example, to generate strong magnetic fields, to heat gases with pulsed currents, and to provide operation to other consumers requiring pulsed power.

The purpose of the invention is to increase the steady-state current in a load.

This goal is achieved by the fact that in an electric machine source of pulses containing two electric machines located on one shaft, one of which is a synchronous generator containing a stator with a winding, a rotor with a DC excitation choke and a damper winding the stator is connected to

load through switching devices, the second machine is made asynchronous with a three-phase stator winding, having the number of pole pairs p2 and connected in parallel with a three-phase stator winding of a synchronous generator, having a number of pole pairs pi less than P2 , work in parallel to the load. A synchronous generator is used to drive the asynchronous generator. Moreover, the ratio of the number of pole pairs of the synchronous generator pi and the number of pole pairs of the asynchronous generator P2 P1 provides not only stable self-excitation of the asynchronous generator,

Joint venture

about a

but also its operation in steady state in the slip region S, at which the current values in the load are significantly higher than the rated current of the asynchronous generator.

According to the authors, in the field of electrical machine sources of pulses there is no equivalent technical solution that would contain a combination of these distinguishing features, namely: the execution of the second machine in the form of an asynchronous stator winding with a three-phase winding, having the number of pole pairs p2 and connected in parallel with the three-phase stator winding synchronous generator having the number of pole pairs pi less than pa. The combination of new features significantly changes the properties of the electrical machine pulse source and allows us to achieve the goal - an increase in the steady-state load current.

The invention is illustrated in the drawings.

In FIG. 1 is a schematic diagram of an electronic pulse source. One of the packages contains a synchronous generator containing a stator 1 and a rotor 2, on which excitation windings 3 and damper 4 are placed. Its stator winding 5 is connected to a star. An asynchronous generator is made on another package, comprising a stator 6 and a rotor 7 with a short-circuit winding 8. The stator winding 9 of the asynchronous generator is connected to a star. The rotors of the synchronous and asynchronous generators are connected by a shaft 10. The stator windings 5 and 9 of the generators are connected in parallel and are connected by switching devices 11 to the load 12.

In FIG. 2 shows a pie chart of the currents of an asynchronous generator, where 0 is the no-load current; IH is the rated current of the generator, lar is the current of the asynchronous generator when working in the slip region close to the point of maximum torque Am; U is the voltage of the asynchronous generator; j - is the diameter of the circle of currents. Xh.

In the initial state, the rotors 2 and 7 of the generators rotate from the drive motor with a speed n, the switching devices 11 are open, the excitation winding 3 of the synchronous generator is powered by a constant current. The magnetic flux generated by the excitation winding rotates in space with the rotor speed n and induces a three-phase symmetric emf system, frequency pi, in pi, where pi is the number of pole pairs

and

synchronous generator. Since the root windings of the synchronous and asynchronous generators are connected in parallel, under the influence of the emf synchronous generator in the winding core 9 of the asynchronous generator, currents occur, creating a rotating magnetic field in the air gap. Asynchronous magnetic field rotation frequency ... P1

HZ generator

where P2 P2 rg

the number of pole pairs of the root winding 9 of the asynchronous generator. To ensure the mode of the asynchronous generator, it is necessary that the speed of rotation of its rotor n be greater than the speed of rotation

stator t. This condition is satisfied if the number of poles of the asynchronous generator is greater than the number of poles of the synchronous generator pi / pa 1. The slip of the rotor of the asynchronous generator relative to the polator is:

25

Q

P1 - P

w

P-P-1 - P P2

„P1

P1 JP2

- 1

P2

P1 P2

0.

0

5

0

5

0

Upon receipt of a current pulse in the load 12, the switching devices are closed. The duration of the current pulse in the load is determined by the on time of the devices 11 and can reach tens of periods of emf from the duration In the initial part of the pulse, the supercurrent and transient components of the currents, which rapidly decay, have the main effect on the current value. In the final part of the pulse in the load, the current value is mainly determined by steady-state processes in synchronous and asynchronous generators and is equal to the sum of the steady-state currents of synchronous and asynchronous generators. The steady-state current of the synchronous generator is small and cannot be larger than the rated current due to the strong influence of the demagnetizing effect of the core reaction.

The steady state current of the asynchronous generator is determined by the amount of slip. By choosing the ratio of the pairs of poles of the synchronous and asynchronous generators P1 / P2 1, it is possible to ensure the operation of the asynchronous generator with such a slip of 5 S, in which the current value of the asynchronous generator 1AG is much greater than its rated current 1H (Fig. 2.). Since the rotors of the generators are located on the same shaft, the slip value during operation does not change, which provides for a given

rotational speed n constant current

fS

asynchronous generator. The currents of the asynchronous and synchronous generators add up to determine the current in the load 12.

The proposed electrical machine pulse source has a greater value of the steady-state current in the load in comparison with the known, including the prototype. This is achieved by designing the second machine in the form of an asynchronous generator operating on sliding, providing power to the load with a current exceeding significantly the rated current of the generator. The use of the proposed electric machine source of pulses is especially effective in mobile autonomous systems with its drive from the power take-off shaft.

Claims (1)

The claims An electrical machine pulse source containing two electrical machines located on one shaft, one of which is a synchronous generator containing a stator with a winding, a rotor with a DC excitation winding and a damper winding, the stator is connected to load through switching devices, characterized in that, in order to increase the steady-state load current, the other machine is made asynchronous with a three-phase stator winding having the number of pole pairs p2 connected in parallel with the three-phase winding of the synchronous generator stator, having the number of pole pairs pi less than P2.  /////////////// JL ..