CN105429519A - Detection device and detection method for permanent magnet flux linkages of permanent magnet synchronous motor - Google Patents

Abstract

The invention discloses a detection device and a detection method for permanent magnet flux linkages of a permanent magnet synchronous motor. The device comprises a direct current voltage source, a three-phase full-bridge inverter, a high-resistance resistor and the permanent magnet synchronous motor, wherein the direct current voltage source supplies electricity to the three-phase full-bridge inverter; the three-phase full-bridge inverter is connected with the permanent magnet synchronous motor; the midpoint of the direct current voltage source is grounded; and a neutral point of the permanent magnet synchronous motor is grounded through the high-resistance resistor. The method comprises the following steps: obtaining voltages at two ends of the high-resistance resistor as the voltage of the neutral point of the permanent magnet synchronous motor through detection; determining a terminal voltage of the permanent magnet synchronous motor, and subtracting the voltage of the neutral point from the terminal voltage to obtain a phase voltage; calculating three-phase counter electromotive forces by the phase voltage and three-phase phase currents detected by a current sensor; and carrying out integration on the three-phase counter electromotive forces, and synthesizing three-phase permanent magnet flux linkage vectors to obtain the permanent magnet flux linkage of the permanent magnet synchronous motor. According to the detection device and the detection method, the problem that real-time accurate detection of the permanent magnet flux linkages of the motor in closed-loop control of the permanent magnet synchronous motor is solved.

Description

A kind of checkout gear of permanent-magnetism synchronous motor permanent magnetic magnetic linkage and detection method

Technical field

The present invention relates to a kind of permagnetic synchronous motor, particularly relate to a kind of checkout gear and detection method of permanent-magnetism synchronous motor permanent magnetic magnetic linkage, belong to permagnetic synchronous motor control field.

Background technology

Permagnetic synchronous motor has that structure is simple, power density is high, control the plurality of advantages such as simple.In recent years, permagnetic synchronous motor obtains increasingly extensive application in the industrial circles such as high-performance governing system and servo-control system.

High-performance permanent magnet synchronous motor control system needs permanent magnet flux linkage information accurately.But permanent magnet flux linkage fluctuation and loss of excitation can cause that the motor feels hot and torque performance is deteriorated, under serious conditions motor may out of control with scrap.At present, known prior art is from design of electrical motor angle, optimizes magnetic structure, and reduce loss of excitation risk, these class methods belong to static prevention scheme.And to the operating loss of excitation of motor, often will arrive after causing obvious fault and just shut down detection, can only be called a kind of off-line analysis method after loss of excitation, the loss of excitation degree of energy initiating failure is often very serious.

Therefore, the permanent magnet flux linkage Detection results of prior art is difficult to meet the requirement of permagnetic synchronous motor high performance control.How accurately to detect permanent-magnetism synchronous motor permanent magnetic magnetic linkage in real time, be that prior art has problem to be solved.

Summary of the invention

Technical problem: the object of the invention is the problem being difficult to accurately detect in real time to solve motor permanent magnet flux linkage in permagnetic synchronous motor closed-loop control, and propose a kind of checkout gear and detection method of permanent-magnetism synchronous motor permanent magnetic magnetic linkage.

Technical scheme: for achieving the above object, the technical solution used in the present invention is:

A checkout gear for permanent-magnetism synchronous motor permanent magnetic magnetic linkage, for detecting the permanent magnet flux linkage of permagnetic synchronous motor; It is characterized in that: comprise direct voltage source, three-phase full-bridge inverter and high resistance measurement, wherein, described direct voltage source provides power supply for three-phase full-bridge inverter, and the neutral earthing of direct voltage source; Described three-phase full-bridge inverter connects permagnetic synchronous motor, and the neutral point of permagnetic synchronous motor is via high resistance measurement ground connection.

Three-phase full-bridge inverter described above is formed by three branch circuit parallel connections, each bar branch road all comprises two metal-oxide-semiconductors of series connection mutually, and each metal-oxide-semiconductor is all connected with anti-paralleled diode, three branch roads of described three-phase full-bridge inverter connect A, B, C three-phase of permagnetic synchronous motor respectively.

High resistance measurement described above refers to that resistance value is greater than the resistance device of 100M Ω.

For achieving the above object, another technical scheme that the present invention adopts is:

A detection method for the checkout gear of permanent-magnetism synchronous motor permanent magnetic magnetic linkage, is characterized in that comprising the steps:

(1) voltage at high resistance measurement two ends is detected, as permagnetic synchronous motor neutral point voltage;

(2) according to the on off operating mode of three-phase full-bridge inverter turn on process and afterflow process power tube and fly-wheel diode, determine permagnetic synchronous motor three phase terminals voltage, deduct neutral point voltage by described terminal voltage, obtain permagnetic synchronous motor three-phase phase voltage;

(3) detect permagnetic synchronous motor A, B, C three-phase phase current, in conjunction with aforementioned three-phase phase voltage, calculate three-phase opposite potential according to phase voltage equilibrium equation;

(4) permanent-magnetism synchronous motor permanent magnetic magnetic linkage is calculated.

In step described above (2), the defining method of permagnetic synchronous motor three phase terminals voltage is: first judge that three-phase full-bridge inverter is operated in turn on process or afterflow process, when being operated in turn on process, three phase terminals voltage is determined by the state of power tube: if the upper brachium pontis power tube of certain phase is open-minded, then this phase terminal voltage numerical value be direct voltage source amplitude 1/2, polarity is being for just, if the lower brachium pontis power tube of certain phase is open-minded, then this phase terminal voltage numerical value be direct voltage source amplitude 1/2, polarity is negative; When being operated in afterflow process, three phase terminals voltage is determined by the state of fly-wheel diode: if the upper brachium pontis fly-wheel diode of certain phase is open-minded, then this phase terminal voltage numerical value be direct voltage source amplitude 1/2, polarity is being for just, if the lower brachium pontis fly-wheel diode of certain phase is open-minded, then this phase terminal voltage numerical value be direct voltage source amplitude 1/2, polarity is negative.

Whether the method judging that three-phase full-bridge inverter is operated in turn on process or afterflow process described above is: detect three-phase full-bridge inverter power tube and all turn off, when three-phase full-bridge inverter power tube be not all turn off time, then show that three-phase full-bridge inverter is in turn on process; When three-phase full-bridge inverter power tube all turns off, then show that three-phase full-bridge inverter is in afterflow process.

The method calculating three-phase opposite potential in step described above (3) is: utilize current sensor to detect permagnetic synchronous motor three-phase phase current i _a, i _b, i _c, then the three-phase phase voltage u in integrating step (2) _a, u _b, u _c, according to following formula permagnetic synchronous motor phase voltage equilibrium equation, calculate permagnetic synchronous motor three-phase opposite potential e _a, e _b, e _c:

$\left\{\begin{array}{c}{e}_a=u_a-i_a{R}_a-L_a\frac{{\mathrm{di}}_a}{dt}\\ e_b=u_b-i_b{R}_b-L_b\frac{{\mathrm{di}}_b}{dt}\\ e_c=u_c-i_c{R}_c-L_c\frac{{\mathrm{di}}_c}{dt}\end{array}\right.$

Wherein, R _a, R _b, R _cbe respectively permagnetic synchronous motor three-phase phase resistance, L _a, L _b, L _cbe respectively permagnetic synchronous motor three-phase phase inductance.

The method that step described above (4) calculates permanent-magnetism synchronous motor permanent magnetic magnetic linkage obtains three-phase permanent magnetic linkage to described permagnetic synchronous motor A, B, C three-phase opposite potential integration:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{ra}=\∫e_{a}dt\\ {\mathrm{\ψ}}_{rb}=\∫e_{b}dt\\ {\mathrm{\ψ}}_{rc}=\∫e_{c}dt\end{array}\right.$

Converted by CLARK, by described three-phase permanent flux linkage vector synthesis, obtain permanent-magnetism synchronous motor permanent magnetic magnetic linkage:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{r\mathrm{\α}}=\frac{2}{3}{\mathrm{\ψ}}_{ra}-\frac{1}{3}{\mathrm{\ψ}}_{rb}-\frac{1}{3}{\mathrm{\ψ}}_{rc}\\ {\mathrm{\ψ}}_{r\mathrm{\β}}=\frac{\sqrt{3}}{3}{\mathrm{\ψ}}_{rb}-\frac{\sqrt{3}}{3}{\mathrm{\ψ}}_{rc}\end{array}\right..$

Beneficial effect: advantage of the present invention and beneficial effect mainly:

1, of the present invention for detecting permanent-magnetism synchronous motor permanent magnetic magnetic linkage device, structure is simple, and accuracy of detection is high, and real-time is good.2, the detection method of permanent-magnetism synchronous motor permanent magnetic magnetic linkage of the present invention, the required parameter of electric machine is few, and amount of calculation is little, solves the problem that motor permanent magnet flux linkage in permagnetic synchronous motor closed-loop control is difficult to accurately detect in real time.

Accompanying drawing explanation

Fig. 1 is the structure of the detecting device block diagram of permanent-magnetism synchronous motor permanent magnetic magnetic linkage.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is described in further detail.Should be appreciated that specific embodiment described herein only for explaining the present invention, being not intended to limit the present invention.

As shown in Figure 1, the checkout gear of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage of the present invention, comprise direct voltage source, three-phase full-bridge inverter and high resistance measurement, for detecting the opposite potential of permagnetic synchronous motor, wherein, direct voltage source connects three-phase full-bridge inverter, for three-phase full-bridge inverter provides power supply, and the neutral earthing of described direct voltage source; Described three-phase full-bridge inverter is formed by three branch circuit parallel connections, each bar branch road all comprises two metal-oxide-semiconductors of series connection mutually, and each metal-oxide-semiconductor is all connected with anti-paralleled diode, three branch roads of described three-phase full-bridge inverter connect A, B, C three-phase of permagnetic synchronous motor respectively, and the neutral point of permagnetic synchronous motor is via high resistance measurement ground connection, wherein, described high resistance measurement refers to that resistance value is greater than the resistance device of 100M Ω.

Based on above-described checkout gear, the detection method of the checkout gear of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage of the present invention, comprises the following steps:

Step 1: determine permagnetic synchronous motor neutral point voltage

By direct voltage source neutral earthing, by permagnetic synchronous motor neutral point by high resistance measurement ground connection, detect the voltage obtaining high resistance measurement two ends, using the voltage at described high resistance measurement two ends as permagnetic synchronous motor neutral point voltage;

Step 2: determine permagnetic synchronous motor A, B, C three phase terminals voltage and phase voltage

The determination of permanent magnet synchronous electric set end voltage, three-phase full-bridge inverter turn on process and afterflow process two kinds of situations can be divided to consider respectively, whether three-phase full-bridge inverter turn on process and afterflow process are all turned off by detection three-phase full-bridge inverter power tube judges: when three-phase full-bridge inverter power tube is not whole shutoff, then show that three-phase full-bridge inverter is in turn on process; When three-phase full-bridge inverter power tube all turns off, then show that three-phase full-bridge inverter is in afterflow process;

Three-phase full-bridge inverter turn on process, permagnetic synchronous motor A, B, C three phase terminals voltage is determined by the state of power tube: if the upper brachium pontis power tube of certain phase is open-minded, then this phase terminal voltage numerical value be direct voltage source amplitude 1/2, polarity is being for just, if the lower brachium pontis power tube of certain phase is open-minded, then this phase terminal voltage numerical value be direct voltage source amplitude 1/2, polarity is negative;

Three-phase full-bridge inverter afterflow process, permagnetic synchronous motor A, B, C three phase terminals voltage is determined by the state of fly-wheel diode: because afterflow process three-phase full-bridge inverter power tube all turns off, permagnetic synchronous motor A, B, the fly-wheel diode afterflow of C respectively by respective connected three-phase full-bridge inverter brachium pontis is uniquely opened, if the upper brachium pontis fly-wheel diode of certain phase is open-minded, then this phase terminal voltage numerical value is 1/2 of direct voltage source amplitude, polarity is just, if the lower brachium pontis fly-wheel diode of certain phase is open-minded, then this phase terminal voltage numerical value is 1/2 of direct voltage source amplitude, polarity is negative,

Above-mentioned permanent magnet synchronous electric set end voltage is deducted above-mentioned permagnetic synchronous motor neutral point voltage, obtains permagnetic synchronous motor phase voltage.

Step 3: calculate permagnetic synchronous motor A, B, C three-phase opposite potential

Adopt above-mentioned permagnetic synchronous motor A, B, C three-phase phase voltage u _a, u _b, u _cand A, B, C three-phase phase current i obtained is detected by current sensor _a, i _b, i _c, according to permagnetic synchronous motor phase voltage equilibrium equation, calculate A, B, C three-phase opposite potential:

$\left\{\begin{array}{c}{e}_a=u_a-i_a{R}_a-L_a\frac{{\mathrm{di}}_a}{dt}\\ e_b=u_b-i_b{R}_b-L_b\frac{{\mathrm{di}}_b}{dt}\\ e_c=u_c-i_c{R}_c-L_c\frac{{\mathrm{di}}_c}{dt}\end{array}\right.$

R _a, R _b, R _cbe respectively the phase resistance of permagnetic synchronous motor A, B, C three-phase, L _a, L _b, L _cbe respectively the phase inductance of permagnetic synchronous motor A, B, C three-phase.

Step 4: calculate permanent-magnetism synchronous motor permanent magnetic magnetic linkage

Three-phase permanent magnetic linkage is obtained to above-mentioned permagnetic synchronous motor A, B, C three-phase opposite potential integration:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{ra}=\∫e_{a}dt\\ {\mathrm{\ψ}}_{rb}=\∫e_{b}dt\\ {\mathrm{\ψ}}_{rc}=\∫e_{c}dt\end{array}\right.$

Converted by CLARK, by described three-phase permanent flux linkage vector synthesis, obtain permanent-magnetism synchronous motor permanent magnetic magnetic linkage:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{r\mathrm{\α}}=\frac{2}{3}{\mathrm{\ψ}}_{ra}-\frac{1}{3}{\mathrm{\ψ}}_{rb}-\frac{1}{3}{\mathrm{\ψ}}_{rc}\\ {\mathrm{\ψ}}_{r\mathrm{\β}}=\frac{\sqrt{3}}{3}{\mathrm{\ψ}}_{rb}-\frac{\sqrt{3}}{3}{\mathrm{\ψ}}_{rc}\end{array}\right.$

These are only embodiments of the present invention, it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.

Claims (8)

1. a checkout gear for permanent-magnetism synchronous motor permanent magnetic magnetic linkage, for detecting the permanent magnet flux linkage of permagnetic synchronous motor; It is characterized in that: comprise direct voltage source, three-phase full-bridge inverter and high resistance measurement, wherein, described direct voltage source provides power supply for three-phase full-bridge inverter, and the neutral earthing of direct voltage source; Described three-phase full-bridge inverter connects permagnetic synchronous motor, and the neutral point of permagnetic synchronous motor is via high resistance measurement ground connection.

2. the checkout gear of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage as claimed in claim 1, it is characterized in that: described three-phase full-bridge inverter is formed by three branch circuit parallel connections, each bar branch road all comprises two metal-oxide-semiconductors of series connection mutually, and each metal-oxide-semiconductor is all connected with anti-paralleled diode, three branch roads of described three-phase full-bridge inverter connect A, B, C three-phase of permagnetic synchronous motor respectively.

3. the checkout gear of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage as claimed in claim 1, is characterized in that: described high resistance measurement refers to that resistance value is greater than the resistance device of 100M Ω.

4., based on the detection method of the checkout gear of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage as claimed in claim 1, it is characterized in that comprising the steps:

(1) voltage at high resistance measurement two ends is detected, as permagnetic synchronous motor neutral point voltage;

(2) according to the on off operating mode of three-phase full-bridge inverter turn on process and afterflow process power tube and fly-wheel diode, determine permagnetic synchronous motor three phase terminals voltage, deduct neutral point voltage by described terminal voltage, obtain permagnetic synchronous motor three-phase phase voltage;

(3) detect permagnetic synchronous motor A, B, C three-phase phase current, in conjunction with aforementioned three-phase phase voltage, calculate three-phase opposite potential according to phase voltage equilibrium equation;

(4) permanent-magnetism synchronous motor permanent magnetic magnetic linkage is calculated.

5. the detection method of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage as claimed in claim 4, it is characterized in that: in described step (2), the defining method of permagnetic synchronous motor three phase terminals voltage is: first judge that three-phase full-bridge inverter is operated in turn on process or afterflow process, when being operated in turn on process, three phase terminals voltage is determined by the state of power tube: if the upper brachium pontis power tube of certain phase is open-minded, then this phase terminal voltage numerical value is 1/2 of direct voltage source amplitude, polarity is just, if the lower brachium pontis power tube of certain phase is open-minded, then this phase terminal voltage numerical value is 1/2 of direct voltage source amplitude, polarity is negative, when being operated in afterflow process, three phase terminals voltage is determined by the state of fly-wheel diode: if the upper brachium pontis fly-wheel diode of certain phase is open-minded, then this phase terminal voltage numerical value be direct voltage source amplitude 1/2, polarity is being for just, if the lower brachium pontis fly-wheel diode of certain phase is open-minded, then this phase terminal voltage numerical value be direct voltage source amplitude 1/2, polarity is negative.

6. the detection method of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage as claimed in claim 5, it is characterized in that: the described method judging that three-phase full-bridge inverter is operated in turn on process or afterflow process is: detect three-phase full-bridge inverter power tube and whether all turn off, when three-phase full-bridge inverter power tube be not all turn off time, then show that three-phase full-bridge inverter is in turn on process; When three-phase full-bridge inverter power tube all turns off, then show that three-phase full-bridge inverter is in afterflow process.

7. the detection method of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage as claimed in claim 4, is characterized in that: the method calculating three-phase opposite potential in described step (3) is: utilize current sensor to detect permagnetic synchronous motor three-phase phase current i _a, i _b, i _c, then the three-phase phase voltage u in integrating step (2) _a, u _b, u _c, according to following formula permagnetic synchronous motor phase voltage equilibrium equation, calculate permagnetic synchronous motor three-phase opposite potential e _a, e _b, e _c:

$\left\{\begin{array}{c}{e}_a=u_a-i_a{R}_a-L_a\frac{{\mathrm{di}}_a}{dt}\\ e_b=u_b-i_b{R}_b-L_b\frac{{\mathrm{di}}_b}{dt}\\ e_c=u_c-i_c{R}_c-L_c\frac{{\mathrm{di}}_c}{dt}\end{array}\right.$

Wherein, R _a, R _b, R _cbe respectively permagnetic synchronous motor three-phase phase resistance, L _a, L _b, L _cbe respectively permagnetic synchronous motor three-phase phase inductance.

8. the detection method of a kind of permanent-magnetism synchronous motor permanent magnetic magnetic linkage as claimed in claim 4, it is characterized in that: the method that described step (4) calculates permanent-magnetism synchronous motor permanent magnetic magnetic linkage obtains three-phase permanent magnetic linkage to described permagnetic synchronous motor A, B, C three-phase opposite potential integration:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{ra}=\∫e_{a}dt\\ {\mathrm{\ψ}}_{rb}=\∫e_{b}dt\\ {\mathrm{\ψ}}_{rc}=\∫e_{c}dt\end{array}\right.$

Converted by CLARK, by described three-phase permanent flux linkage vector synthesis, obtain permanent-magnetism synchronous motor permanent magnetic magnetic linkage:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{r\mathrm{\α}}=\frac{2}{3}{\mathrm{\ψ}}_{r\mathrm{\α}}-\frac{1}{3}{\mathrm{\ψ}}_{rb}-\frac{1}{3}{\mathrm{\ψ}}_{rc}\\ {\mathrm{\ψ}}_{r\mathrm{\β}}=\frac{\sqrt{3}}{3}{\mathrm{\ψ}}_{rb}-\frac{\sqrt{3}}{3}{\mathrm{\ψ}}_{rc}\end{array}\right..$