RU2324249C1 - Multistage accelerator with series commutation of solenoids - Google Patents

Abstract

FIELD: weapons; electromagnetic launchers.

SUBSTANCE: solenoid-type multistage linear electromagnetic accelerator, comprising ferromagnetic projectile, non-magnetic tubular barrel with tractive solenoids coaxially mounted thereon, means for switching solenoid coils in response to control device signals and capacitor power supply units. The solenoids are arranged in groups having separate power supply. When a solenoid in one group switches off, its self-induction energy is distributed to the capacitor power supply unit of another group. The solenoids are fed by means of longitudinal power supply busses. Successive commutation between solenoids in each group is made automatically in response to signals of auxiliary sensor coils.

EFFECT: enhancement of design efficiency, portability and jamming resistance.

2 cl, 1 dwg

Description

In the technique of electromagnetic acceleration of bodies, linear multistage accelerators are known [1-4]. Common disadvantages of accelerators of this type are low efficiency and a large number of control circuits and separate power supply, which complicate the design and reduce the reliability of the accelerator.

The development of accelerator designs goes in several directions.

In [5], a more advanced switching scheme based on a matrix of keys with a diagonal half-bridge load switching was proposed. This solution allows to simplify the design by reducing the total number of keys used. The half-bridge inclusion of the accelerator windings provides increased operating efficiency by returning part of the self-induction energy back to the power source (energy recovery). The disadvantage of the half-bridge circuit is the need to use both lower and upper lockable keys. The management of the lower keys relative to the potential of the common wire (earth) is quite simple, and the control of the upper keys relative to the floating potential requires more complex circuitry.

It is possible to increase the accelerator efficiency by increasing the number of stages while reducing the power of each stage. However, in the compact implementation of such an accelerator, technical difficulties arise associated with the placement of a large number of pulsed power electric circuits in close proximity to the sensitive circuits of sensors and their amplifiers. This requires additional costs to ensure sufficient noise immunity and reliability, which, in turn, further complicates the design of the accelerator.

The prototype of the claimed accelerator is an electromagnetic accelerator of a propelled body [6] with partial recovery of the energy of self-induction of the solenoid windings using transformer coupling between the steps. The disadvantage of this design is the use of complex magnetic cores and the recovery of self-induction energy only with relatively weak magnetic fields that do not cause saturation of the magnetic cores.

The main objective of the proposed solution is to build an effective accelerator with a large number of steps, providing partial recovery of the self-induction energy in strong magnetic fields, allowing the solenoids to be placed on the trunk without gaps between the steps, having high reliability and noise immunity with a simple compact design and a small number of power electric circuits.

This technical problem is solved as follows:

A multi-stage linear electromagnetic accelerator of the solenoid type contains a ferromagnetic shell, a cylindrical non-magnetic barrel with traction solenoids coaxially mounted on it, means for switching the solenoid windings according to the signals of the control device, and a capacitor energy source.

The invention has the following new features that distinguish it from the known:

1. Sequentially located separate accelerating solenoids with thyristor keys are combined by power buses and switching buses in alternating groups so that neighboring solenoids belong to different groups. In this case, each solenoid is switched on with its thyristor key, and the group of solenoids is additionally turned on and off via the switching bus with a group transistor key according to the signals of the control device. The current in the solenoid is turned on while the thyristor key of the solenoid and the transistor group key are opened, the current in the solenoid is turned off by closing the group key, after which the current in the solenoid winding stops, which automatically locks the thyristor key of the solenoid. Each solenoid, except for the main winding, contains an additional sensory winding. An additional winding is connected to the control terminal of the thyristor switch of the next switching stage. At the moment the current is turned off in the main winding of the solenoid, its self-induction EMF induces a pulse in the additional winding, opening the thyristor of the next turn-on stage of the accelerator.

2. Each group of solenoids is powered by its own storage capacitor through a separate power bus. When the current in the winding of any solenoid from one group is turned off, its self-induction energy is sent through the recovery circuit to the capacitor of the other group and charges it, ensuring the reuse of part of the self-induction energy of the solenoids.

The drawing shows a connection diagram of the main parts of the accelerator with two alternately included groups of solenoids.

The numbers on the diagram indicate:

1 - ferromagnetic shell;

2 - trunk;

3 - traction solenoid with a main power winding;

4 - additional sensory winding of the traction solenoid;

5 - thyristor key;

6 - power bus power;

7 - control device;

8 - transistor group key;

9 - power bus switching;

10 - energy recovery circuit;

11 - capacitor energy source.

A multi-stage electromagnetic accelerator is arranged as follows: a ferromagnetic projectile 1 moves inside a cylindrical non-magnetic barrel 2 and is accelerated by the magnetic field of the traction solenoids 3 coaxially mounted on the barrel. Solenoids have additional sensory windings 4, the signal of which opens the thyristor keys 5 of the solenoids. The power supply of the solenoids is carried out by means of power buses 6. The thyristor switch of the first stage is controlled directly by the signal of the control device 7, and the thyristor keys of all other stages are controlled by additional windings. Odd and even solenoids with individual thyristor keys are combined in two groups. The control device generates signals for alternately opening and closing the transistor group keys 8. Each such key commutes its own group of solenoids via switching buses 9. Moreover, the switching buses through recovery circuits 10 are connected to capacitor energy sources 11 of the opposite group. Power supply and switching buses are laid along the accelerator, and individual thyristor switches are installed next to each stage and connected to the touch windings of the previous stages. Such an arrangement allows, with an increase in the number of stages of the accelerator, to maintain compactness and a small number of connecting and power circuits.

Description of the accelerator.

At the initial moment, according to the signal of the control device, the transistor switch of the first group of solenoids is turned on and an opening pulse is applied to the thyristor switch of the solenoid of the first stage. The current from the capacitor of the first group flows through the first solenoid. After a specified time required to accelerate the projectile with the first solenoid, the control device turns off the first group transistor switch and turns on the second group switch. At the moment the current is turned off in the solenoid, an EMF pulse of self-induction appears in its winding, which is transformed through an additional winding to the control terminal of the thyristor of the second stage. The thyristor switch of the second stage opens, the transistor switch of the second group at this moment is already open by the signal of the control device and the current from the second storage capacitor starts to pass through the solenoid of the second stage. The self-induction energy of the disconnected first stage through the energy recovery circuit recharges the storage capacitor of the second group.

The recovery circuit is based on a varistor with a breakdown voltage slightly higher than the initial voltage of the capacitor energy source. The self-induction EMF pulse is limited by the recovery circuit at the level of the sum of the voltage of the capacitor source and the breakdown voltage of the varistor. Maintaining the self-induction EMF at this level, more than two times the initial voltage at the capacitor, causes a rapid drop in current in the disconnected solenoid, preventing the effect of the braking of the projectile by the residual magnetic field of the switched off solenoid.

The alternate switching of two groups of solenoids provides pauses between switching on the steps in each group, sufficient to turn off the thyristor switches in the steps of one group during the operation of the steps of the other group. This allows you to place the solenoids on the trunk directly one after another, without significant gaps.

Further operation of the accelerator is controlled by a control device, which turns on and off the group transistor switches at necessary times. In this case, the sequential successive selection of the accelerator working stage occurs automatically, due to the opening of the thyristor of each next stage by the EMF pulse of the self-induction of the previous stage at the time of its switching off.

The application of the proposed technical solutions allows to reduce the number of transistor switches to one for each group of solenoids, while maintaining the ability to turn on and off all solenoids of a multi-stage accelerator, increase the overall efficiency of converting electric energy of capacitors into kinetic energy of a projectile by reusing part of the energy of self-induction of solenoids. This provides a compact design of a multi-stage accelerator due to the power and switching stages through longitudinal power buses.

Information sources

1. US patent No. 2235201. Electrcic gun. US cl .: 124/3 89/8 310/14.

2. US Patent No. 1241333. Gun US cl .: 124/3 89/8 310/14.

3. US Patent No. 5125321. Apparatus for and method of operating a cylindrical pulsed induction mass launcher. IPC: F41B 6/00.

4. Patent of Russia No. 2258885. Electromagnetic accelerator with rotation of the projectile. IPC: F41B 6/00.

5. US patent No. 5763812. Compact personal rail gun. IPC: F41F 1/00.

6. Patent of Russia No. 2267074. Electromagnetic accelerator propelled body. IPC: F41B 6/00.

Claims (2)

1. A multi-stage linear electromagnetic accelerator of the solenoid type containing a ferromagnetic projectile, a cylindrical non-magnetic barrel with coaxially mounted and sequentially traction solenoids, means for switching solenoid windings according to the signals of the control device, and a capacitor energy source, characterized in that the individual accelerating solenoids with thyristor keys combined by power buses and switching buses in two groups so that the solenoids with odd numbers form the first group , the solenoids with even numbers form the second group, the groups of solenoids are turned on and off through the switching buses by group transistor keys according to the signals of the control device, the current in the solenoid is turned on while the thyristor key of the solenoid and the transistor group key are opened, the current in the solenoid is turned off by closing the group key, after which the current in the coil of the solenoid stops, which causes automatic locking of the thyristor of the solenoid, each solenoid contains two windings: primary power coil and the additional sensor, the additional winding is connected to the control terminal of the thyristor switch next stage at the time of switching off the current in the primary winding of the solenoid, its self-induction EMF induces additional sensor winding pulse thyristor comprising the following steps accelerator. 2. A multi-stage linear electromagnetic accelerator of the solenoid type containing a ferromagnetic projectile, a cylindrical non-magnetic barrel with traction solenoids coaxially mounted on it, means for switching solenoid windings according to the signals of the control device, and a capacitor energy source, characterized in that the individual accelerating solenoids are arranged in series in two groups so that the solenoids with odd numbers form the first group, the solenoids with even numbers form the second group, each the group of solenoids is powered by its storage capacitor, at the moment the current in the power winding of any solenoid from one group is turned off, its self-induction energy is sent through the recovery circuit to the capacitor of the other group and charges it, ensuring the reuse of part of the self-induction energy of the solenoids.