TW201434241A - Device for magnetizing a motor - Google Patents

Abstract

A device comprises three magnetizing units respectively connected to three phase windings connected in Y-connection. Each magnetizing unit has at least one magnetizing module. The magnetizing module has a resonant circuit, an electric switch and a driver circuit. The resonant circuit is connected to one winding for providing a magnetizing current. The electric switch is connected to the resonant circuit. The driver circuit is connected to the electric switch to activate the electric switch, such that the resonant circuit resonates to boost an output voltage. The invention provides equal magnetizing currents to the three phase windings to induce equal magnetic fields. The magnetic fields magnetize a rotor of the motor. After the rotor is magnetized, the magnetic field of the rotor is uniform and is not distorted.

Description

Magnetizing circuit device for electric motor

The present invention is a circuit device, particularly a magnetizing circuit device of an electric motor.

The electric motor mainly includes a rotor and a stator. The conventional rotor includes a magnet type rotor. During the assembly of the motor, the strong magnetic force of the rotor easily attracts iron powder and the like, so that assembly is difficult. In order to improve the aforementioned shortcomings, there is a rotor magnetization technology in which a rotor having no magnetism is first assembled in a stator. When the motor is assembled, an external magnetizing circuit device is used to apply current to the three-phase coil, and each coil generates a magnetic field. The rotor is magnetized, and when the rotor is magnetized, it has the characteristics of a magnet. Since the rotor is not magnetic during the assembly process, the assembly can be simplified.

Please refer to FIG. 8 , the conventional magnetizing circuit device includes a step-up transformer 41 , a rectifier 42 , an isolating switch 43 , a capacitor 44 , an electronic switch 45 , a driving circuit 46 , a first output end 401 and a Second output 402. The electric motor 50 has Y-connected first to third coils 51-53, and the coils 51-53 respectively have a first end and a second end, and the second end is electrically connected in common as a neutral point (N). The first end serves as an input for connecting an external power source, respectively.

The primary side of the step-up transformer 41 is via the isolating switch 43 Connected to the mains (AC/IN), the input end of the rectifier 42 is electrically connected to the secondary side of the step-up transformer 41. The capacitor 44 has a first end and a second end electrically connected to the two outputs of the rectifier 42 respectively. And the first end is connected to the first output terminal 401 via the electronic switch 45, the second end is connected to the second output terminal 402, and the driving circuit 46 is electrically connected to the electronic switch 45.

Since the magnetizing circuit device only provides two output terminals 401, 402, and the coils 51-53 have three input terminals, the existing method is to connect two of the coils in parallel, for example, the first and second coils 51, 52. The first end is commonly connected to the first output 401 such that the first and second coils 51, 52 are formed in parallel, and the first end of the third coil 53 is connected to the second output 402. In this way, the magnetizing circuit device can be connected to the coils 51 to 53 of the motor.

When the isolating switch 43 is turned on, the driving circuit 46 controls the electronic switch 45 to be turned off. The step-up transformer 41 receives an AC voltage from the mains (AC/IN) and increases the amplitude of the AC voltage. The rectifier 42 converts the AC voltage. After rectifying to a DC voltage, the capacitor 44 is charged. After the voltage of the capacitor 44 is established, the isolating switch 43 interrupts the mains (AC/IN) and the step-up transformer 41. The driving circuit 46 controls the electronic switch 45 to be turned on. At this time, the capacitor 44 and the coils 51~ 53 forms a current loop for discharging capacitor 44 at a time such that capacitor 44 outputs a magnetizing current to coils 51-53.

However, since the first and second coils 51, 52 are connected in parallel, the currents I ₁ , I ₂ passing through the first and second coils 51, 52 are lower than the current I ₃ passing through the third coil 53, so the third coil The magnetic field generated by 53 must be greater than the magnetic field generated by the first and second coils 51, 52. For the rotor, the magnetic field induced by the rotor from the coils 51-53 is not uniform, resulting in distortion of the magnetic field of the rotor after magnetization.

The main purpose of the present invention is to provide a magnetizing circuit device for an electric motor, in order to improve the magnetic distortion of the rotor caused by the known magnetizing circuit device being unable to provide a uniform magnetizing current to the three-phase coil of the motor.

The magnetizing circuit device of the present invention comprises three magnetizing units for respectively connecting Y-connected three-phase coils of the motor to provide an average magnetizing current to each phase coil, and each magnetizing unit has at least one magnetizing module, the charging The magnetic module includes: a resonant circuit connected to the coil to provide the magnetizing current; an electronic switch connected to the resonant circuit and having a control end; and a driving circuit connected to the control end of the electronic switch, the driving circuit The on period of the electronic switch is controlled to adjust the magnitude of the magnetization current.

According to the magnetizing circuit device of the present invention, three magnetizing units are respectively connected to the three-phase coils to respectively output a uniform magnetizing current to the three-phase coils, and when the magnetizing current passes through the three-phase coils, the three-phase coils are generated. The uniform magnetic field magnetizes the rotor in the motor, so that the rotor of the motor is magnetized and has uniform magnetic properties, effectively overcoming the problem that the magnetizing circuit device cannot provide a uniform magnetizing current to the three-phase coil and cause magnetic distortion of the rotor. .

10‧‧‧Magnetization unit

11‧‧‧Magnetizing module

111‧‧‧First magnetizing module

112‧‧‧Second magnetization module

113‧‧‧Nth magnetizing module

12‧‧‧Resonance circuit

120‧‧‧Output switch

13‧‧‧Drive circuit

20‧‧‧Electric motor

21‧‧‧First coil

22‧‧‧second coil

23‧‧‧ Third coil

31‧‧‧Isolation switch

32‧‧‧Rectifier circuit

401‧‧‧ first output

402‧‧‧second output

41‧‧‧Step-up transformer

42‧‧‧Rectifier

43‧‧‧Isolation switch

44‧‧‧ Capacitors

45‧‧‧Electronic switch

46‧‧‧ drive circuit

50‧‧‧Electric motor

51‧‧‧First coil

52‧‧‧second coil

53‧‧‧third coil

Figure 1: Schematic diagram of the connection of the motor coil of the present magnetizing circuit device.

Figure 2: Circuit diagram of the magnetizing module of the present creation.

Figure 3: Equivalent circuit diagram of the magnetization module when the electronic switch is turned on.

Figure 4: Equivalent circuit diagram of the magnetization module when the electronic switch is turned off.

Figure 5a~5f: Schematic diagram of the current and polarity of each inductor and capacitor when the magnetization module resonates.

Figure 6: Waveform diagram of the electronic switch, the output voltage, the second capacitor terminal voltage, the first inductor current, and the second inductor current.

Figure 7: Block diagram of the magnetization module in series with this creation.

Figure 8 is a circuit diagram of a conventional magnetizing circuit device.

Referring to FIG. 1, the present invention includes three magnetizing units 10 for respectively connecting the three-phase coils 21-23 of the motor 20 to provide an average magnetizing current to the phase coils 21-23. The three-phase coils 21 to 23 are first to third coils 21 to 23, respectively, and the coils 21 to 23 have a first end and a second end, respectively, and the second end is electrically connected in common as a neutral point (N). The first end serves as an input for connecting an external power source, respectively.

Referring to FIG. 2 , each magnetizing unit 10 has one or more magnetizing modules 11 connected in series. The magnetizing module 11 includes a resonant circuit 12 , an electronic switch Q and a driving circuit 13 .

Taking the first coil 21 as an example, the resonant circuit 12 is connected to the first coil 21 to provide a magnetizing current. The resonant circuit 12 includes a first capacitor C1, a first inductor L1, a second capacitor C2 and a second inductor. L2.

The first capacitor C1 may be a super capacitor. The first capacitor C1 has a first end and a second end, and a second end is connected to the second end of the first coil 21.

The first inductor L1 has a first end and a second end, and the first end thereof is connected to the first end of the first capacitor C1.

The second capacitor C2 has a first end and a second end connected to the second end of the first inductor L1 and the second end of the first capacitor C1.

The second inductor L2 has a first end and a second end, the first end of which is connected to the second end of the first inductor L1, and the second end of the second inductor L2 is connected to the first coil via an output switch 120. At the first end of the 21, the output switch 120 can be a power transistor, a solid state power device or a conventional electromagnetic relay. The second end of the second inductor L2 and the second end of the first capacitor C1 serve as an output end of the resonating unit 12 to generate an output voltage (Vout) to the first coil 21, when current passes through the first coil 21. The first coil 21 corresponds to a magnetic field that generates magnetization.

The electronic switch Q includes a first end, a second end and a control end. The first end and the second end are respectively connected to the first end and the second end of the second capacitor C2 and connected in parallel with the second capacitor C2. The electronic switch Q can be a power transistor, with a gate as the control terminal, a drain as the first end, and a source as the second end.

The driving circuit 13 is connected to the control end of the electronic switch Q. The driving circuit 13 controls the conduction period of the electronic switch Q, and transmits the resonant characteristics of the inductors L1 and L2 and the capacitors C1 and C2 to control the magnetizing current. size.

Referring to FIG. 2, the first capacitor C1 can be connected to the output end of a rectifying circuit 32 via an isolating switch 31. The input end of the rectifying circuit 32 is electrically connected to the mains (AC/IN) when the disconnecting switch 31 is turned on. , The output switch 120 interrupts the connection of the resonant circuit 12 to the first coil 21, which rectifies the commercial power (AC/IN) AC power to a DC power source to charge the first capacitor C1.

After the first capacitor C1 is completed, the isolating switch 31 interrupts the connection between the mains (AC/IN) and the rectifying circuit 32, and the output switch 120 is turned on, and the driving circuit 13 controls the conduction period of the electronic switch Q, so that The electric energy stored by the first capacitor C1 is transmitted to the first coil 21 through the resonance action of the resonance circuit 21, and when the first coil 21 receives the output current of the resonance circuit 21, the first coil 21 generates a magnetic field correspondingly to magnetize the rotor. . The foregoing resonant operation will be described as follows: each conduction period can be subdivided into first to sixth intervals t1 to t6 according to the polarity directions of the first and second inductors L1, L2 and the second capacitor C2.

Referring to FIG. 3, FIG. 5a and FIG. 6, in the first interval t1, the driving circuit 13 controls the electronic switch Q to be turned on, the two ends of the second capacitor C2 form a short circuit, and the voltage across the second capacitor C2. (Vds) is zero, and the equivalent circuit of the resonant circuit 12 is as shown in FIG. 3, and the resonant circuit 12 has no resonance action. As shown in FIG. 3, the first capacitor C1 forms a loop with the first inductor L1, the terminal voltage of the first capacitor C1 is equivalent to an input voltage (Vi), and the second inductor L2 and the first coil 21 Another circuit is formed, the two circuits are independent of each other, the first inductor L1 receives the electric energy of the first capacitor C1 to store energy, so that the current (IL1) of the first inductor L1 rises, and the second inductor L2 releases the electric energy. To the first coil 21, the current (IL2) of the second inductor L2 and the output voltage (Vout) of the resonance circuit 12 are decremented.

In the subsequent second to sixth intervals t2 to t6, the driving circuit 13 controls the electronic switch Q to be turned off. The equivalent circuit of the resonant circuit 12 is as shown in FIG. 4, and the resonant circuit 12 starts to resonate, and the resonant frequency is:

Referring to FIG. 5b and FIG. 6, in the second interval t2, the electronic switch Q is just turned off, and the second capacitor C2 starts to store energy, so that the terminal voltage (Vds) of the second capacitor C2 is gradually increased, and the first inductor L1 is gradually increased. Still storing energy from the first capacitor C1, the second inductor L2 still releases power to the first coil 21, so the current (IL1) of the first inductor L1 is maintained rising, and the current of the second inductor L2 (IL2) And the output voltage (Vout) of the resonant circuit 12 is maintained to decrease in the second interval t2 until the current (IL2) and the output voltage (Vout) of the second inductor L2 are decremented to a minimum value.

Referring to FIG. 5c and FIG. 6, in the third interval t3, the second capacitor C2, the first inductor L1 and the second inductor L2 are stored, so the terminal voltage (Vds) of the second capacitor C2 is maintained increasing, first The currents (IL1, IL2) with the second inductors I1, L2 are incremented until the current (IL1) of the first inductor L1 reaches a maximum value.

Referring to FIG. 5d and FIG. 6, in the fourth interval t4, the second capacitor C2 and the second inductor L2 are stored, and the first inductor L1 is discharged, so the output voltage (Vout) and the second capacitor C2 are The terminal voltage (Vds) is incremented, the current (IL1) of the first inductor L1 is decreased, and the current (IL2) of the second inductor L2 is incremented until the terminal voltage (Vds) of the second capacitor C2 reaches a maximum value.

Please refer to FIG. 5e and FIG. 6. In the fifth interval t5, the first The two capacitors C2 are discharged from the first inductor L1, and the second inductor L2 is stored, so that the output voltage (Vout) continues to increase, the terminal voltage (Vds) of the second capacitor C2 decreases, and the current of the first inductor L1 (IL1) Decreasing, the current (IL2) of the second inductor L2 is incremented until the current (IL2) and the output voltage (Vout) of the second inductor L2 reach a maximum value, wherein the maximum value of the output voltage (Vout) is the first capacitor C1, the sum of the voltages of the first inductor L1 and the second inductor L2.

Referring to FIG. 5f and FIG. 6, in the sixth interval t6, the first inductor L1, the second inductor L2, the first capacitor C1 and the second capacitor C2 release the first coil 21, and the output voltage (at this time) Vout) decreases from the maximum value, and when the current (IL1) of the first inductor L1 is minimized, a conduction period is completed.

When the magnetizing operation is completed, the output switch 120 interrupts the connection of the resonant circuit 12 and the first coil 21, and the isolating switch 31 is turned on to charge the first capacitor C1 again, when the first capacitor C1 is charged. After that, the next magnetizing action can be performed.

Since the three-phase coils 21 to 23 of the motor are respectively connected to the magnetizing module 11, the magnetizing module 11 can control the conduction period of the electronic switch Q by the driving circuit 13, respectively, so that the resonant circuits 12 are output to the respective coils 21~ The magnetizing currents of 23 are uniform, thereby causing the coils 21 to 23 to generate a uniform magnetic field to magnetize the rotor, so that the magnetic field of the rotor after magnetization is uniformized without distortion.

In the prior art, the boosting transformer is used to boost the electrolytic capacitor, and the resonant characteristic of the resonant circuit 12 is utilized to make the output voltage (Vout) several times larger than the input voltage (Vi) (for example, 6 or 7 times larger). ) In order to generate the instantaneous large current required in the magnetization process; the first capacitor C1 of the present invention uses an ultracapacitor as a main energy storage component, and the capacitance of the ultracapacitor is tens of thousands of times the capacitance of the existing electrolytic capacitor, and the ultracapacitor has High power density, low equivalent series resistance, fast charge and discharge, long charge and discharge cycle life and instantaneous release of large current, so the capacitance of existing electrolytic capacitors is relatively limited, the creation of ultracapacitors not only greatly reduce the energy storage system Volume and weight can increase the charging efficiency and extend the life of the creation.

Therefore, the use of a transformer without the use of a transformer can make the overall volume of the magnetizing circuit device small, and the use of the ultracapacitor system to store higher electric energy in this creation makes the volume of the creation smaller and the energy storage increased, so that the utility can effectively improve Energy density, high energy storage and discharge purposes.

As described above, a single magnetizing module 11 is used to apply a current to the coil as an example. Referring to FIG. 7 , in another embodiment, the magnetizing unit 10 can have a plurality of magnetizing modules 11 , and the magnetizing modules 11 are respectively defined as first to Nth magnetizing modules 111 〜 113, N is an integer greater than or equal to 2.

Taking the first coil 21 as an example, the second end of the second inductor L2 in the first magnetizing module 111 is connected to the first end of the first coil 21, and the first capacitor C1 in the Nth magnetizing module 113 The second end of the first inductor 21 is connected to the second end of the first inductor 21, and the second end of the second inductor L2 is connected to the second capacitor C1 of the first N-1 magnetization module. The second magnetizing module 111 forms a series structure, and the second end of the second inductor L2 in the first magnetizing module 111 and the second end of the first capacitor C1 in the Nth magnetizing module 113 resonate The output of unit 10 to generate an output voltage (Vout) is given to the first coil 21.

Therefore, the output voltage (Vout) of each resonant circuit 12 is made several times larger than the input voltage (Vi) by the resonance characteristic of the resonant circuit 12 in each magnetizing module 12, and the present invention is a visible motor. The requirements are to connect the appropriate number of magnetizing modules 12 to form the magnetizing unit 10, so that the magnetizing currents outputted by the respective magnetizing units 10 to the coils 21 to 23 can be adjusted correspondingly, so the present invention is applicable to motors of various specifications. For example, a motor with a larger horsepower can be connected in series with more magnetizing modules 11, and more magnetizing modules 11 can provide a larger magnetizing current to the coils 21~23, and the coils 21~23 generate a larger magnetic field. To magnetize the rotor.

Furthermore, in the present invention, the driving circuit 13 controls the switching frequency of the electronic switch Q to be slightly lower than the resonant frequency f _{res of the} resonant circuit 12, so that the equivalent impedance of the present magnetizing circuit device is capacitive and can be combined with the magnetized motor. The inductive matching of the coils 21 to 23 helps to reduce the impedance of the entire magnetizing circuit, thereby increasing the magnetizing current.

10‧‧‧Magnetization unit

20‧‧‧Electric motor

21‧‧‧First coil

22‧‧‧second coil

23‧‧‧ Third coil

Claims (8)

A magnetizing circuit device for an electric motor, comprising three magnetizing units for respectively connecting a Y-connected three-phase coil of the motor to provide an average magnetizing current to each phase coil, each magnetizing unit having at least one magnetizing module, The magnetizing module comprises: a resonant circuit connected to the coil to provide the magnetizing current; an electronic switch connected to the resonant circuit and having a control end; and a driving circuit connected to the control end of the electronic switch, the driving circuit The conduction period of the electronic switch is controlled to adjust the magnitude of the magnetization current. The magnetizing circuit device of the motor of claim 1, wherein each of the magnetizing units has a single magnetizing module. The magnetizing circuit device of the motor of claim 1, wherein each of the magnetizing units comprises a plurality of magnetizing modules connected in series. The magnetizing circuit device of the motor of claim 2, the resonant circuit comprising: a first capacitor having a first end and a second end, the second end of which is coupled to the coil; a first inductor having a first end and a second end, the first end of which is connected to the first end of the first capacitor; a second capacitor has a first end and a second end respectively connected to the second end of the first inductor And a second end of the first capacitor; and a second inductor having a first end and a second end, the first end of which is connected to the second end of the first inductor, and the second end of the second inductor is connected The coil; the electronic switch is connected in parallel to the second capacitor. The magnetizing circuit device of the motor of claim 3, wherein each of the magnetizing units comprises a first to an Nth magnetizing module, and N is an integer greater than or equal to 2, wherein each resonant circuit comprises: a first capacitor, The first inductor has a first end and a second end, the first end of which is connected to the first end of the first capacitor; and the second capacitor has a first end And a second end connected to the second end of the first inductor and the second end of the first capacitor respectively; and a second inductor having a first end and a second end, the first end of which is connected a second end of the first inductor; the electronic switch is connected in parallel with the second capacitor; wherein the second end of the second inductor in the first magnetizing module is connected to the coil; A second end of the capacitor is connected to the second end of the second inductor of the Nth magnetizing module. The magnetizing circuit device of the motor of claim 4 or 5, wherein the first capacitor is an ultracapacitor. The magnetizing circuit device of the motor of claim 4, wherein the second end of the second inductor is connected to the coil via an output switch. The magnetizing circuit device of the motor of claim 5, wherein the second end of the second inductor in the first magnetizing module is connected to the coil via an output switch.