CN102042204A - Control device for moving-magnetic type linear compressor piston displacement - Google Patents

Abstract

The invention discloses a control device for moving-magnetic type linear compressor piston displacement, in particular to an automatic sensing detection and control system for moving-magnetic type linear compressor piston displacement. The system mainly comprises a current detecting unit, a voltage detecting unit, a piston displacement analogue computer, a displacement amplitude detecting unit, an initial piston equilibrium position input unit, a piston displacement equilibrium position deviation detecting unit, a piston top dead center displacement computer, a piston top dead center displacement control unit, a command value input unit and a power driving unit. The piston top dead center displacement is taken as a control target, coil voltage and coil current of a linear motor are detected, and the stroke and top dead center displacement of the piston are calculated. The control unit controls the variation between the piston top dead center displacement and the command value as well as the velocity of variation, so as to obtain a regulating command value of the power driving unit, and system capacity is regulated, thus regulating the value of the piston top dead center displacement.

Description

A kind of moving-magnetic linear compressor piston displacement control gear

Technical field

The present invention relates to a kind of moving-magnetic linear compressor piston displacement control gear, specifically a kind of self-sensing of moving-magnetic linear compressor piston displacement detects and control system.

Background technique

Linear compressor is a kind of novel efficient Reciprocting piston compressor, and the connecting rod that it does not have the conventional piston compressor to be had is directly done linear reciprocating motion by the linear motor driving piston.Owing to there is not connecting rod, its piston stroke and upper dead center position are unrestricted, and be relevant with the energy size of adding to system, and therefore, piston displacement is variable.

The piston stroke of linear compressor and upper dead center displacement are determining the refrigerating capacity and the coefficient of performance of system, because piston stroke is relevant with the air displacement of compressor, and the upper dead center displacement has determined the clearance volume of compressor, thereby influences volumetric efficiency, final decision the coefficient of performance of system.The piston stroke of linear compressor is relevant with the energy of the linear electric motor that add to the upper dead center displacement, in order to guarantee that compressor is efficient, the operation of high reliability, must effectively control the piston displacement of compressor, and the precondition of control is to know the displacement of piston.In the early stage control system, displacement transducer has been installed has been carried out the piston displacement detection, but the introducing of displacement transducer has not only increased the cost of system, and makes compressor arrangement become complicated, because the difference of the self performance of displacement transducer, after being encapsulated in the freezer compressor housing, be subjected to electromagnetic interference easily, influenced the reliability of complete machine, in case break down, then the freezer compressor system can't proper functioning.

The self-sensing technology is a kind of technology of utilizing linear electric motor itself as displacement transducer, and it is different from traditional displacement transducer, have simple in structure, cost is low, strong robustness and for ease of maintenaince wait advantage.Moving-magnetic linear compressor is done reciprocating linear motion by moving magnetic linear motor driving piston, because the stability of moving-magnetic type linear motor self parameter, make it become possibility as piston displacement sensor, it is mainly by measuring the voltage and the electric current at linear motor coil two ends, the displacement that draws piston by differential and integral operation.

For the controlling method of linear compressor, mainly contain two kinds of open loop and closed loop controls, but since the not real-time and the non-high speed property of open loop control, close-loop feedback control system commonly used, and regulating voltage, electric current or other driving parameter are to reach the control purpose.Linear compressor is the vibration system of a typical nonlinear, many couplings, its piston is in the unrestricted motion state, the main influences such as exhaust pressure, driving voltage value, frequency of okperation and ambient temperature of machine by compression of the stroke of piston and upper dead center displacement, therefore for the accurate control of piston displacement, it needs a large amount of precise math model and laboratory data, and the transfer function of compressor assembly can change with the change of working conditions of compressor, and it has very big uncertainty.And fuzzy control is a kind of system model that do not need, based on the non-linear intelligent control of fuzzy set theory, fuzzy language variable and fuzzy logic inference.

Summary of the invention

A kind of moving-magnetic linear compressor piston displacement control gear among the present invention has overcome the existing complex structure of control system in the prior art, need install displacement transducer additional, poor reliability, the high deficiency of control accuracy difference cost, make that moving-magnetic linear compressor control system structure is simple more, performance is stable more, cost is lower, use and industrialization has great importance for the commerce of moving-magnetic linear compressor.

The objective of the invention is to overcome the deficiencies in the prior art, a kind of moving-magnetic linear compressor piston displacement control gear is provided, specifically a kind of self-sensing of moving-magnetic linear compressor piston displacement detects and control system.

A kind of moving-magnetic linear compressor piston displacement control gear comprises current detecting unit 1, voltage detection unit 2, piston displacement analogue computer 3, displacement amplitude detection unit 4, initial piston equilibrium position input unit 5, piston displacement equilibrium position offset detection unit 6, piston upper dead center displacement computing unit 7, piston upper dead center displacement control unit 8, bid value input unit 9 and triode ac switch power drive unit 10;

Described current detecting unit 1 and voltage detection unit 2 respectively with 3 unidirectional connections of piston displacement analogue computer; Described piston displacement analogue computer 3 is by displacement amplitude detection unit 4 and 7 unidirectional connections of piston upper dead center displacement computing unit; Described piston upper dead center displacement computing unit 7 and bid value input unit 9 respectively with 8 unidirectional connections of piston upper dead center displacement control unit; Be connected with power drive unit 10 on the described piston upper dead center displacement control unit 8; Described triode ac switch power drive unit 10 is arranged in the compressor drive circuit, with linear motor coil, start electric capacity, sampling resistor and power supply is single-phase is connected, forms the closed-loop path.

Be connected with evaporating temperature detection unit 11 and condensing temperature detection unit 12 respectively on the described piston displacement equilibrium position offset detection unit 6, wherein evaporating temperature detection unit 11 and condensing temperature detection unit 12 unidirectional being connected on the piston upper dead center displacement control unit 8.

Described piston displacement analogue computer 3, the voltage that detects by electric current and voltage detection unit 2 to current detecting unit 1 detection carries out the displacement waveform that analog computation draws piston, calculates the stroke value of pistons by piston displacement amplitude detection unit 4.

Described piston displacement upper dead center computing unit 7 is by calculating the upper dead center value that can draw linear compressor to the piston stroke value of bid value input unit 9 inputs, the piston equilibrium position side-play amount of piston displacement equilibrium position offset detection unit 6 detections and the piston initial rest position of initial piston equilibrium position input unit 5 inputs.

Described piston upper dead center displacement control unit 8 is handled by variation and variance ratio between the piston upper dead center value of piston upper dead center value that piston upper dead center displacement computing unit 7 is drawn and 9 inputs of bid value input unit, thereby draw the regulating command value of power drive unit 10, by power drive unit 10 regulating system energy from the displacement of regulating piston upper dead center, thereby reach the piston upper dead center value of bid value input unit 9 input.

Described piston displacement equilibrium position offset detection unit 6 is calculated by the condensing temperature that evaporating temperature and condensing temperature detection unit 12 to 11 detections of evaporating temperature detection unit detect, and can draw piston equilibrium position side-play amount.

Described piston upper dead center displacement fuzzy control unit 8 carries out Fuzzy processing by variation and the variance ratio between the evaporating temperature that the evaporating temperature value and the bid value input unit 9 of 11 detections of evaporating temperature detection unit are imported, and draws the control target value of piston displacement upper dead center.

Described piston upper dead center displacement fuzzy control unit 8 carries out Fuzzy processing by variation and the variance ratio between the condensing temperature that the condensing temperature value and the bid value input unit 9 of 12 detections of condensing temperature detection unit are imported, and draws the control target value of piston displacement upper dead center.

The present invention proposes a kind of moving-magnetic linear compressor piston displacement control gear, specifically a kind of self-sensing of moving-magnetic linear compressor piston displacement detects and Fuzzy control system.It mainly comprises current detecting unit, voltage detection unit, piston displacement analogue computer, displacement amplitude detection unit, initial piston equilibrium position input unit, piston displacement equilibrium position offset detection unit, piston upper dead center displacement computing unit, piston upper dead center displacement control unit, bid value input unit and power drive unit.Moving-magnetic linear compressor piston displacement control gear is a control target with the displacement of piston upper dead center, coil current by current detecting unit detection of straight lines motor, voltage by voltage detection unit detection of straight lines motor coil two ends, the piston displacement computing unit is by carrying out the displacement waveform that analog computation draws piston to the voltage and current that detects, by the stroke value of piston displacement amplitude detection unit calculating piston, piston displacement upper dead center computing unit is by the piston stroke value to the input of bid value input unit, the piston initial rest position of piston equilibrium position side-play amount that piston displacement equilibrium position offset detection unit detects and the input of initial piston equilibrium position input unit is calculated the upper dead center value that can draw linear compressor.Piston upper dead center displacement control unit is handled by variation and variance ratio between the piston upper dead center value of piston upper dead center value that piston upper dead center displacement computing unit is drawn and the input of bid value input unit, thereby draw the regulating command value of power drive unit, by power drive unit regulating system energy from the displacement of regulating piston upper dead center, thereby reach the piston upper dead center value of bid value input unit input.This moving-magnetic linear compressor piston displacement control gear has that control accuracy height, response are fast, good stability, low cost and other advantages.

Description of drawings

Fig. 1 is a moving-magnetic type linear motor coil equivalent circuit diagram of the present invention;

Fig. 2 is linear compressor piston displacement detecting analog circut figure of the present invention;

Fig. 3 is a moving-magnetic linear compressor piston motion illustraton of model of the present invention;

Fig. 4 is moving-magnetic linear compressor piston displacement control gear figure of the present invention;

Fig. 5 is the refrigerated air-conditioning system of specific embodiments of the invention 1 moving-magnetic linear compressor piston displacement control gear figure;

Embodiment

Accompanying drawing is the specific embodiment of the present invention;

Below in conjunction with accompanying drawing content of the present invention is described in further detail:

Fig. 1 is the equivalent circuit diagram of moving-magnetic linear compressor motor coil, after considering iron loss, the D.C. resistance Rc of motor coil and the influence of iron loss Rl is merged into equivalent resistance Re, equally inductance L c is replaced by equivalent inductance Le.The velocity response electromotive force is difficult to directly measure from motor coil, but can be derived as by the voltage uc and the current i c at linear motor coil two ends

${\mathrm{\ϵ}}_0\left(t\right)=\mathrm{\α}\frac{\mathrm{dx}}{\mathrm{dt}}=u_c\left(t\right)-R_e{i}_c\left(t\right)-L_e\frac{{\mathrm{di}}_c\left(t\right)}{\mathrm{dt}}$

Then the piston displacement of linear compressor is

$x\left(t\right)=\frac{1}{\mathrm{\α}}\∫(u_c\left(t\right)-R_e{i}_c\left(t\right)-L_e\frac{{\mathrm{di}}_c\left(t\right)}{\mathrm{dt}})\mathrm{dt}$

Therefore, voltage and electric current that the detection of linear compressor piston displacement can be by the Test coil two ends, it is carried out computing after, carry out amplitude and detect the stroke that can draw piston.But equivalent resistance, equivalent inductance and the thrust coefficient (a) that relate to linear electric motor during piston displacement detects, experimental research show that the equivalent inductance of moving-magnetic type linear motor, equivalent resistance and thrust coefficient are to keep constant in the stroke of linear motor rotor.

The analog circut that Fig. 2 detects for piston displacement, it mainly is made up of amplification circuit, integration circuit, differentiator and eliminator, is ignoring eliminator (R ₆And C ₆) situation under, by circuit analysis as can be known piston displacement detect analog circut and be output as

$u_x=\&Integral;(\frac{R_2}{R_1{R}_3{C}_5}{u}_c\left(t\right)-\frac{R_i}{R_4{C}_5}{i}_c\left(t\right)-\frac{R_i{C}_4}{{\mathrm{<figure-callout\; id="5"\; label="C"\; filenames="HDA0000039924640000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_5}\frac{{\mathrm{di}}_c\left(t\right)}{\mathrm{dt}})\mathrm{dt}$

And the calculated value of linear compressor piston displacement can be expressed as

$\mathrm{\&alpha;x}\left(t\right)=\&Integral;(u_c\left(t\right)-R_e{i}_c\left(t\right)-L_e\frac{{\mathrm{di}}_c\left(t\right)}{\mathrm{dt}})\mathrm{dt}$

Therefore, by the output and the theoretical value of analogue simulator circuit, can draw displacement detecting Design of Simulating Circuits formula and be

$R_3=\frac{R_2}{R_1{C}_5},$ $R_4=\frac{R_i}{R_e{C}_5},$ $C_4=\frac{L_e{C}_5}{R_i}$

Fig. 3 is the piston motion illustraton of model of linear compressor, and the compresser cylinder cylinder cap is the dead-center position of piston displacement, and the piston initial rest position is A ₀, piston equilibrium position side-play amount is x ₀, piston stroke is S, then the upper dead center displacement of its piston is

x _t＝A ₀+x ₀-S/2

The initial rest position A of piston ₀Relevant with the design and the assembly process of compressor, it is a definite value.Piston equilibrium displacement side-play amount x ₀Relevant with the exhaust pressure of compressor with the suction pressure difference, its can along with the increase of pressure reduction away from the cylinder head side, its value can measure by experiment.

Fig. 3 is moving-magnetic linear compressor piston displacement control gear figure, and it mainly comprises current detecting unit 1, voltage detection unit 2, piston displacement analogue computer 3, displacement amplitude detection unit 4, initial piston equilibrium position input unit 5, piston displacement equilibrium position offset detection unit 6, piston upper dead center displacement computing unit 7, piston upper dead center displacement control unit 8, bid value input unit 9 and power drive unit 10.Moving-magnetic linear compressor piston displacement control gear is a control target with the displacement of piston upper dead center, coil current by current detecting unit 1 detection of straight lines motor, voltage by voltage detection unit 2 detection of straight lines motor coil two ends, piston displacement computing unit 3 is by carrying out the displacement waveform that analog computation draws piston to the voltage and current that detects, by the stroke value of piston displacement amplitude detection unit 4 calculating pistons, piston displacement upper dead center computing unit 7 is by the piston stroke value to 9 inputs of bid value input unit, the piston initial rest position of piston equilibrium position side-play amount that piston displacement equilibrium position offset detection unit 6 detects and 5 inputs of initial piston equilibrium position input unit is calculated the upper dead center value that can draw linear compressor.Piston upper dead center displacement control unit 8 is handled by variation and variance ratio between the piston upper dead center value of piston upper dead center value that piston upper dead center displacement computing unit 7 is drawn and 9 inputs of bid value input unit, thereby draw the regulating command value of power drive unit 10, by power drive unit 10 regulating system energy from the displacement of regulating piston upper dead center, thereby reach the piston upper dead center value of bid value input unit 9 input.

Piston displacement equilibrium position offset detection unit 6 can pass through to detect the suction and discharge pressure difference of compressor, thereby draws piston displacement equilibrium position side-play amount.

Referring to shown in Figure 5, a kind of refrigerated air-conditioning system has mainly comprised current detecting unit 1, voltage detection unit 2, piston displacement analogue computer 3, displacement amplitude detection unit 4, initial piston equilibrium position input unit 5, piston displacement equilibrium position offset detection unit 6, piston upper dead center displacement computing unit 7, piston upper dead center displacement fuzzy control unit 8, bid value input unit 9, triode ac switch power drive unit 10, evaporating temperature detection unit 11 and condensing temperature detection unit 12 with moving-magnetic linear compressor piston displacement control gear.Refrigerated air-conditioning system is control target with moving-magnetic linear compressor piston displacement control gear with displacement of piston upper dead center and evaporating temperature, coil current by current detecting unit 1 detection of straight lines motor, voltage by voltage detection unit 2 detection of straight lines motor coil two ends, piston displacement computing unit 3 calculates the stroke value of piston by the voltage and current that detects is carried out the displacement waveform that analog computation draws piston by piston displacement amplitude detection unit 4.Piston displacement equilibrium position offset detection unit 6 is calculated by the condensing temperature that evaporating temperature and condensing temperature detection unit 12 to 11 detections of evaporating temperature detection unit detect, can draw piston equilibrium position side-play amount, piston displacement upper dead center computing unit 7 is by calculating the upper dead center value that can draw linear compressor to the piston stroke value of bid value input unit 9 inputs, the piston equilibrium position side-play amount of piston displacement equilibrium position offset detection unit 6 detections and the piston initial rest position of initial piston equilibrium position input unit 5 inputs.

For refrigeration system, piston upper dead center displacement fuzzy control unit 8 carries out Fuzzy processing by variation and the variance ratio between the evaporating temperature that the evaporating temperature value and the bid value input unit 9 of 11 detections of evaporating temperature detection unit are imported, at first draw the control target value of piston displacement upper dead center, then, piston upper dead center displacement fuzzy control unit 8 is handled by variation and variance ratio between the control target value of piston upper dead center value that piston upper dead center displacement computing unit 7 is drawn and piston displacement upper dead center, thereby draw the regulating command value of triode ac switch power drive unit 10, by triode ac switch power drive unit 10 regulating system energy from the displacement of regulating piston upper dead center, thereby reach the evaporating temperature value of bid value input unit 9 input.

For heating, piston upper dead center displacement fuzzy control unit 8 carries out Fuzzy processing by variation and the variance ratio between the condensing temperature that the condensing temperature value and the bid value input unit 9 of 12 detections of condensing temperature detection unit are imported, at first draw the control target value of piston displacement upper dead center, then, piston upper dead center displacement fuzzy control unit 8 is handled by variation and variance ratio between the control target value of piston upper dead center value that piston upper dead center displacement computing unit 7 is drawn and piston displacement upper dead center, thereby draw the regulating command value of triode ac switch power drive unit 10, by triode ac switch power drive unit 10 regulating system energy from the displacement of regulating piston upper dead center, thereby reach the condensing temperature value of bid value input unit 9 input.

Above content is to further describing that the present invention did in conjunction with concrete preferred implementation; can not assert that the specific embodiment of the present invention only limits to this; for the general technical staff of the technical field of the invention; without departing from the inventive concept of the premise; can also make some simple deduction or replace, all should be considered as belonging to the present invention and determine scope of patent protection by claims of being submitted to.

Claims (8)

1. moving-magnetic linear compressor piston displacement control gear is characterized in that:

Comprise current detecting unit (1), voltage detection unit (2), piston displacement analogue computer (3), displacement amplitude detection unit (4), initial piston equilibrium position input unit (5), piston displacement equilibrium position offset detection unit (6), piston upper dead center displacement computing unit (7), piston upper dead center displacement control unit (8), bid value input unit (9) and triode ac switch power drive unit (10);

Described current detecting unit (1) and voltage detection unit (2) respectively with unidirectional connection of piston displacement analogue computer (3); Described piston displacement analogue computer (3) is by displacement amplitude detection unit (4) and unidirectional connection of piston upper dead center displacement computing unit (7); Described piston upper dead center displacement computing unit (7) and bid value input unit (9) respectively with unidirectional connection of piston upper dead center displacement control unit (8); Be connected with power drive unit (10) on the described piston upper dead center displacement control unit (8); Described triode ac switch power drive unit (10) is arranged in the compressor drive circuit, with linear motor coil, start electric capacity, sampling resistor and power supply is single-phase is connected, forms the closed-loop path.

2. moving-magnetic linear compressor piston displacement control gear according to claim 1, it is characterized in that: be connected with evaporating temperature detection unit (11) and condensing temperature detection unit (12) on the described piston displacement equilibrium position offset detection unit (6) respectively, wherein evaporating temperature detection unit (11) and condensing temperature detection unit (12) are unidirectional is connected on the piston upper dead center displacement control unit (8).

3. according to claim 1 or 2 described moving-magnetic linear compressor piston displacement control gear, it is characterized in that:

Described piston displacement analogue computer (3), the voltage that detects by electric current and voltage detection unit (2) to current detecting unit (1) detection carries out the displacement waveform that analog computation draws piston, calculates the stroke value of piston by piston displacement amplitude detection unit (4).

4. according to claim 1 or 2 described moving-magnetic linear compressor piston displacement control gear, it is characterized in that: described piston displacement upper dead center computing unit (7) is by calculating the upper dead center value that can draw linear compressor to the piston stroke value of bid value input unit (9) input, the piston equilibrium position side-play amount of piston displacement equilibrium position offset detection unit (6) detection and the piston initial rest position of initial piston equilibrium position input unit (5) input.

5. according to claim 1 or 2 described moving-magnetic linear compressor piston displacement control gear, it is characterized in that:

Described piston upper dead center displacement control unit (8) is handled by variation and variance ratio between the piston upper dead center value of piston upper dead center value that piston upper dead center displacement computing unit (7) is drawn and bid value input unit (9) input, thereby draw the regulating command value of power drive unit (10), by power drive unit (10) regulating system energy from the displacement of regulating piston upper dead center, thereby reach the piston upper dead center value of bid value input unit (9) input.

6. according to claim 1 or 2 described moving-magnetic linear compressor piston displacement control gear, it is characterized in that:

Described piston displacement equilibrium position offset detection unit (6) is calculated by the condensing temperature that evaporating temperature and condensing temperature detection unit (12) to evaporating temperature detection unit (11) detection detect, and can draw piston equilibrium position side-play amount.

7. according to claim 1 or 2 described moving-magnetic linear compressor piston displacement control gear, it is characterized in that:

Described piston upper dead center displacement fuzzy control unit (8) carries out Fuzzy processing by variation and the variance ratio between the evaporating temperature that the evaporating temperature value and the bid value input unit (9) of evaporating temperature detection unit (11) detection are imported, and draws the control target value of piston displacement upper dead center.

8. according to the described moving-magnetic linear compressor piston displacement of claim 2 control gear, it is characterized in that:

Described piston upper dead center displacement fuzzy control unit (8) carries out Fuzzy processing by variation and the variance ratio between the condensing temperature that the condensing temperature value and the bid value input unit (9) of condensing temperature detection unit (12) detection are imported, and draws the control target value of piston displacement upper dead center.

Images