RU2508594C1 - Method of adapting oscillation frequency of generator pump lifter-pistons to linear oscillator circuit resonance frequency - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: method of adapting oscillation frequency of generator pump lifter-pistons to linear oscillator circuit in braking power recovery exploits control system to change fluid control valves into opposite positions with delay after every cycle of electric power pulse generation during displacement of said lifter-piston from one extreme point to the other one. Delay duration is selected to increase working fluid pressure in line communicating the motor-pump with generator pump to magnitude whereat oscillation frequency of generator pump lifter-pistons complies with resonance frequency of liner oscillator. Then, control system drives fluid flow control valves to opposite positions to generate regular electric power pulse with period equal to that of previous pulse.

EFFECT: complete recovery of vehicle braking kinetic energy over the entire range of speeds.

1 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to the field of power engineering.

BACKGROUND

The method of adapting the oscillation frequency of the armature-pistons of the pump generator to the resonant frequency of the linear generator circuit is applicable to the power plant of any machine as part of the pump generator and motor pump and allows you to fully recover the kinetic energy of braking of the power take-off shaft in the entire speed range. As an example, a recovery method is considered with reference to a vehicle. In its analogue, patent 2394341 “Stationary magnetization coil of the armature of a linear electric machine”, patent 2352797 “Method of valve drive by the working medium of a piston machine”, patent 2422654 “Synchronizer of movement of armature-pistons in antiphase of a free-piston pump-generator” are used in its analogue.

The power plant of the vehicle consists of a pulsed electro-hydraulic pump-generator (hereinafter - pump-generator), a hydraulic motor-pump (hereinafter - motor-pump) and a control system. The composition of the pump generator (see the figure) includes stator magnets 1, 2 (electromagnets or, as shown in the figure, permanent magnets, hereinafter referred to as magnets), armature pistons 3, 4 (hereinafter referred to as anchors), magnetization coils of anchors 5, 6 (hereinafter referred to as anchor coils), valves for controlling the flow of working fluid 7, 8 (patent 2352797, hereinafter referred to as valves). In addition, there are channels 9, 13 and pipelines 10, 11, 12, 14, 15. The pump generator converts electricity into pressure energy of the working fluid to drive the motor pump in pump mode, the shaft of which is connected to the wheel shaft. A motor pump is a hydraulic machine of any design with a reversible action, the shaft of which is connected to the wheel shaft. The power system operates as follows.

The control system of the power plant (not shown in the figure) from the electric power source (battery, generator, etc.) delivers a voltage pulse of one sign to the armature coil 5 of the pump generator, and a different sign to the armature coil 6. Since the anchors 3, 4 are made of soft magnetic material, corresponding magnetic poles appear at their ends (patent 2394341). If their position is as shown in the figure, then the left end of the armature 3 with the north magnetic pole is pushed out from the left ring gap of magnet 1 with the north magnetic pole, and its right end with the south magnetic pole is pulled into the left ring gap of magnet 2 with the north magnetic pole . Similarly, the anchor 4 interacts with the right annular clearances of the magnets 2 and 1, and the anchors 3, 4 begin oncoming movement. The fluid from the right end cavity of the armature 3 and the left end cavity of the armature 4 through the pipe 12 and channel 13 enters the motor pump (not shown) and causes its shaft to rotate. From the motor pump, the spent fluid is returned through channel 9 through pipelines 10, 11 to the left end cavity of the armature 3 and the right end cavity of the armature 4. When the anchors reach the extreme points of convergence, the control system changes the signs of the voltage pulses supplied to coils 5, 6 and simultaneously translates the valves 7, 8 to opposite positions. The anchors begin to diverge, and the liquid from the left end cavity of the armature 3 and the right end cavity of the armature 4 through pipelines 10, 11 and channel 13 flows to the motor pump, and through channel 9 and pipe 12 it returns to the right end cavity of the armature 3 and the left end cavity anchors 4. In the future, the control system continues to continuously change the signs of voltage pulses on the coils of the anchors 5, 6 and the position of the valves 7, 8 to the opposite, so the fluid continues to move in one direction and the motor-pump shaft rotates in the same direction. This mode is typical for maximum acceleration and maximum vehicle speed. To reduce the set acceleration rate between the fluid supply cycles from the pump generator to the motor pump, pauses are organized. To do this, the control system stops the supply of pulses to the coils of the anchors 5, 6 and puts one of the valves 7 or 8 in the opposite position, and the liquid from the output of the motor pump through channel 9, through valve 7, pipeline 14 and channel 13 again enters its input almost without resistance to their movement. That is, during each pause, the energy transfer from the pump-generator to the motor-pump is interrupted. Thus, the duration of the pause is inversely proportional to the set acceleration rate, or, what is the same, directly proportional to the rate of decrease in the set acceleration. The power transmitted to the motor-pump from the pump-generator is reduced inversely with the duration of the pause. In this case, the duration of the voltage pulses remains constant and corresponds to the time of complete movement of the anchors 3, 4 from one extreme position to another.

The action of the power plant in the mode of recovery of braking energy.

When the vehicle is moving, the wheel shaft drives the motor pump, the fluid from which flows through the channel 9 and pipelines 10, 11 into the left end cavity of the armature 3 and into the right end cavity of the armature 4. The anchors 3, 4 begin oncoming movement and squeeze the liquid out the right end cavity of the armature 3 and the left end cavity of the armature 4. The fluid from these cavities through the pipe 12 and channel 13 is returned to the motor pump. When the anchors 3, 4 move in the annular gaps of the magnets 1, 2 in the bodies of the magnets 1, 2, alternating magnetic fluxes are induced, as a result of which electricity pulses are generated in the coils of the anchors 5, 6, which are sent to the battery. In this case, the vehicle receives a braking impulse. When the anchors reach the extreme points of convergence, the control system transfers the valves 7, 8 to the extreme points of divergence. Now the fluid from the motor pump through channel 9 and pipelines 14, 12 enters the right end cavity of the armature 3 and into the left end cavity of the armature 4, and through pipelines 10, 11 and channel 13 it returns to the motor pump. The anchors diverge, and in the coils of the anchors 5, 6 pulses of electricity of the opposite sign are generated, and the vehicle receives another braking pulse. In the future, the control system, transferring valves 7, 8 from one extreme position to another, provides the generation of electricity in the coils of the anchors 5, 6.

Synchronization of the movement of the armature-pistons of the pump generator (patent 2422654): due to inaccuracy in the manufacture of the armature-pistons of the pump generator - the inequality of their masses, distortions in shape and size and other factors, their speed in absolute value in antiphase will inevitably differ. The movement of the pump-generator armature is synchronized by breaking the circuit of one of the armature coils 5 or 6 for a certain time. For example, if the speed of the armature 3 is less than the speed of the armature 4, the control system breaks the bias coil 6. The magnetic poles of the armature 4 disappear, and its speed decreases. At the moment at which the arrival of anchors to the extreme points of movement is ensured, the control system restores the magnetization coil circuit of the armature 6. If the speed of the armature 4 is less than the speed of the armature 3, the control system acts in a similar way.

OBJECT OF THE INVENTION

The aim of the invention is to ensure complete recovery of the kinetic energy of braking of the vehicle in the entire range of vehicle speeds.

SUMMARY OF THE INVENTION

When recovering kinetic energy of braking due to a decrease in vehicle speed, the angular speed of rotation of the wheel shaft and the shaft of the motor pump decreases, the speed of movement of the working fluid in the line between the motor pump and the pump generator decreases and, as a result, the speed of the oscillatory movements of the anchors. The effective conversion of the kinetic energy of the armature of a linear generator into electricity, as in a generator with a rotating rotor, is observed in a narrow range of the oscillation frequency of the armature close to the resonant frequency of the generator circuit. Deviation from this frequency in any direction leads to a decrease in the efficiency of energy conversion - to a decrease in the quality factor of the generator circuit. Therefore, to ensure a stable frequency of oscillatory movements of the anchors in the entire range of vehicle speeds, it is necessary to ensure that at the time of each start of the supply of the working fluid to the end cavities of the anchors, the working fluid pressure is the same. For this, after moving the anchors from one extreme point of movement to another extreme point, the control system transfers the valves 7, 8 to opposite positions with a certain delay. As a result of the delay, the liquid path through the pump generator is blocked. Since the motor-pump continues to rotate as the vehicle moves, the fluid pressure in the line between the motor-pump and the pump-generator increases. At the moment when the fluid pressure reaches a value at which the frequency of the oscillatory movement of the anchors coincides with the resonant frequency of the generator circuit, the control system puts the valves 7, 8 in opposite positions, and the next pulse of electricity is generated with a period equal to the previous pulse of electricity generation.

This means that the generator operates in the mode of maximum quality factor of the generator circuit - a necessary condition for ensuring the maximum efficiency of converting the kinetic energy of anchors into electricity in the entire range of vehicle speeds from maximum speed to almost zero.

SUMMARY OF THE INVENTION

A method of adapting the oscillation frequency of the armature of the pump generator to the resonant frequency of the linear oscillator circuit used in a power plant of a machine with recovery of kinetic energy of the power take-off shaft, including a pulsed electro-hydraulic pump generator, consisting of a linear electric generator with armature pistons and working flow control valves liquids, a hydraulic motor pump and a power plant control system, characterized in that after each cycle of generating a pulse of electricity at moving the pump-generator armature-piston from one extreme point of movement to another extreme point of movement, the control system transfers the fluid flow control valves to opposite positions with a delay, the duration of which is determined so that the working fluid pressure in the line connecting the motor-pump to the pump-generator increased to a value at which the frequency of the oscillatory movements of the armature-pistons of the pump generator coincides with the resonant frequency of the circuit of the linear generator, after which the control system puts the fluid flow control valves in opposite positions, and the next pulse of electricity is generated with a period equal to the previous pulse of electricity generation.

TECHNICAL APPLICABILITY OF THE INVENTION

Materials and technology for the implementation of the claimed invention do not go beyond the scope of modern capabilities. At the current level of development of electronics, the creation of a control system is quite an ordinary task.

GRAPHIC MATERIAL

Figure. Schematic diagram of the pump-generator of the vehicle power system.

1, 2 - stator magnets; 3, 4 - magnetization coils of anchors; 5, 6 - magnetization coils of anchors; 7, 8 - fluid flow control valves; 9, 13 - channels; 10, 11, 12, 14, 15 - pipelines.

Claims (1)

A method of adapting the oscillation frequency of the armature of the pump generator to the resonant frequency of the linear oscillator circuit used in a power plant of a machine with recovery of kinetic energy of the power take-off shaft, including a pulsed electro-hydraulic pump generator, consisting of a linear electric generator with armature pistons and working flow control valves liquids, a hydraulic motor pump and a power plant control system, characterized in that after each cycle of generating a pulse of electricity at moving the pump-generator armature-piston from one extreme point of movement to another extreme point of movement, the control system transfers the fluid flow control valves to opposite positions with a delay, the duration of which is determined so that the working fluid pressure in the line connecting the motor-pump to the pump-generator increased to a value at which the frequency of the oscillatory movements of the armature-pistons of the pump generator coincides with the resonant frequency of the circuit of the linear generator, after which the control system transfers the fluid flow control valves to opposite positions and the next pulse of electricity is generated with a period equal to the previous pulse of electricity generation.