阅读说明：本技术 升降压斩波式直流电机驱动装置以及电动设备 (Boost-buck chopper type direct current motor driving device and electric equipment ) 是由 李静怡 于 2019-11-24 设计创作，主要内容包括：本发明提供一种升降压斩波式永磁直流电机驱动装置以及电动设备。该永磁直流电机驱动装置包括：永磁直流电机；直流电源部；以及升降压斩波式斩波器,其中,升降压斩波式斩波器具有m个斩波单元,每个斩波单元包含上桥臂和下桥臂、以及第一电源输出端和第二电源输出端,上桥臂包含至少一个功率开关管、至少一个电感、至少一个二极管以及开关控制端,下桥臂包含至少一个功率开关管、至少一个电容、至少一个二极管以及开关控制端,控制信号包含分别与m个斩波单元相对应并且按照预定相位错开规则而形成的m个单元控制信号,每一个单元控制信号包含与对应的斩波单元中的两个开关控制端相对应的两个开关控制信号。(The invention provides a buck-boost chopper type permanent magnet direct current motor driving device and electric equipment. This permanent magnetism direct current motor drive arrangement includes: a permanent magnet DC motor; a DC power supply unit; the buck-boost chopper comprises m chopper units, each chopper unit comprises an upper bridge arm, a lower bridge arm, a first power output end and a second power output end, the upper bridge arm comprises at least one power switching tube, at least one inductor, at least one diode and a switch control end, the lower bridge arm comprises at least one power switching tube, at least one capacitor, at least one diode and a switch control end, the control signals comprise m unit control signals which correspond to the m chopper units respectively and are formed according to a preset phase staggering rule, and each unit control signal comprises two switch control signals which correspond to the two switch control ends in the corresponding chopper unit.)

1. A buck-boost chopper DC motor drive, comprising:

a DC motor having a rated voltage;

a DC power supply unit having a constant voltage corresponding to the rated voltage; and

a buck-boost chopper that converts the constant voltage to a variable voltage based on a control signal and supplies the variable voltage to the DC motor,

wherein the buck-boost chopper has m chopper units,

each of the chopper units includes upper and lower arms, and first and second power supply output terminals,

the upper bridge arm and the lower bridge arm are connected in series,

the upper bridge arm is connected with the positive pole of the direct current power supply part, the lower bridge arm is connected with the negative pole of the direct current power supply part,

the upper bridge arm comprises at least one power switching tube, at least one inductor, at least one diode, at least one capacitor and a switch control end,

the power switch tube is used as an upper bridge arm switch tube and is connected with the inductor in series,

the diode is used as an upper bridge arm diode, the power switch tube is used as an upper bridge arm switch tube, and the diodes, the power switch tube and the capacitor are connected in parallel,

the lower bridge arm comprises at least one power switching tube as a lower bridge arm switching tube, at least one diode as a lower bridge arm diode and a switch control end,

the lower bridge arm switching tube is connected with the lower bridge arm diode in reverse parallel,

each of the power switch tubes has a control electrode,

the switch control terminal is formed based on the control pole,

the control signal includes m unit control signals respectively corresponding to the m chopper units and formed in accordance with a predetermined phase shift rule,

each of the cell control signals includes two switch control signals corresponding to two of the switch control terminals in the corresponding chopper cell,

the switch control end in the upper bridge arm is used as an upper bridge arm switch control end, the switch control end in the lower bridge arm is used as a lower bridge arm switch control end for correspondingly receiving the two switch control signals,

the first power supply output end is arranged between the upper bridge arm and the lower bridge arm, the second power supply output end is arranged at the end part of the lower bridge arm connected with the direct-current power supply part,

m pairs of power supply output terminals are formed by the m first power supply output terminals of all the chopping units and the m second power supply output terminals of all the chopping units respectively corresponding to each other,

the direct current motor includes:

a housing;

m pairs of electric brushes fixed in the machine shell;

a stator arranged in the casing and including m pairs of main magnetic poles corresponding to the m pairs of brushes; and

a rotor disposed in the stator and including a plurality of armature windings coupled to each other in a predetermined coupling manner,

each pair of the main magnetic poles comprises an adjacent S-polarity main magnetic pole and an adjacent N-polarity main magnetic pole,

two of the brushes of each pair are located adjacent,

each pair of the brushes comprises an S-pole corresponding brush corresponding to the S-pole main magnetic pole and an N-pole corresponding brush corresponding to the N-pole main magnetic pole,

leading-out ends of the brushes corresponding to all S poles form m first wiring ends, and leading-out ends of the brushes corresponding to all N poles form m second wiring ends; or all the N poles correspond to the leading-out ends of the brushes to form m first terminals, all the S poles correspond to the leading-out ends of the brushes to form m second terminals,

the m first terminals and the m second terminals respectively form m pairs of external terminals,

the m pairs of external connecting terminals are connected with the m pairs of power output terminals in a one-to-one correspondence manner,

and m is a positive integer not less than 2.

2. The buck-boost chopper dc motor drive of claim 1, further comprising:

the switching frequency fs of the upper bridge arm switching tube, the inductance value Lr of the inductor and the capacitance value Cr of the capacitor in each chopper unit satisfy the following relations:

3. the buck-boost chopper dc motor drive of claim 1, further comprising:

wherein the predetermined phase shift rule is that m phases corresponding to the m unit control signals are sequentially shifted by m times of a switching period as m predetermined phases,

in each chopper unit, the switch control signal corresponding to the upper arm switch control end is set as a reference switch control signal, the phase of the reference switch control signal is determined according to the predetermined phase corresponding to the unit control signal, and the switch control signal corresponding to the lower arm switch control end and the reference switch control signal are set to be opposite to each other; alternatively, the first and second electrodes may be,

the m is an even number, and the m is an even number,

the predetermined phase shift rule is that m phases corresponding to the m unit control signals are sequentially shifted by m-th of a switching period as m predetermined phases,

in each chopper unit, the switch control signal corresponding to the upper arm switch control terminal is set as a reference switch control signal whose phase is determined according to the predetermined phase corresponding to the unit control signal, and the switch control signal corresponding to the lower arm switch control terminal and the reference switch control signal are set to be opposite to each other.

4. The buck-boost chopper dc motor drive of claim 1, further comprising:

a control part including a controller and an amplifier,

wherein the controller generates the m unit control signals according to the predetermined phase staggering rule,

the amplifier amplifies the two switch control signals in each unit control signal and provides the amplified two switch control signals to two switch control ends in the corresponding chopper units.

5. The buck-boost chopper dc motor drive of claim 4, wherein:

wherein the amplifier is composed of m independent amplifying units corresponding to the m chopper units,

each amplifying unit is provided with an amplified signal output part which is composed of two amplified signal output ends.

6. The buck-boost chopper dc motor drive of claim 1, further comprising:

the upper bridge arm and the lower bridge arm respectively comprise one power switch tube, and when all the power switch tubes have the same maximum output current I₁The maximum current of the direct current motor is I_maxWhen m satisfies the following condition: m is more than 1.1 (I)_max÷I₁) (ii) a Alternatively, the first and second electrodes may be,

the upper bridge arm and the lower bridge arm respectively comprise p power switch tubes which are connected in parallel, and when all the power switch tubes have the same maximum output current I₁The maximum current of the direct current motor is I_maxAnd m satisfies the following condition: m is more than 1.1 (I)_max÷(k×p×I₁) P is a positive integer not less than 2, k is a parallel coefficient, 1/p<k<1。

7. The buck-boost chopper dc motor drive of claim 1, further comprising:

wherein the predetermined coupling manner is any one of a single stack, a multiple stack, and a complex wave.

8. The buck-boost chopper dc motor drive of claim 1, further comprising:

the power switch tube is a semi-control device or a full-control device, the semi-control device is a common thyristor, and the full-control device is any one of an electric field effect transistor, a gate turn-off thyristor, an integrated gate commutation thyristor, an insulated gate bipolar transistor and an electric power bipolar transistor.

9. An electrically powered device, comprising:

a buck-boost chopper type direct current motor driving device,

the buck-boost chopper type dc motor driving apparatus according to any one of claims 1 to 8.

10. The motorized equipment of claim 9, wherein:

wherein, the electrical equipment is any one of electric automobile, electric bicycle, artillery, tank and radar.

Technical Field

The invention belongs to the field of direct current motor driving devices, and particularly relates to a buck-boost chopper type direct current motor driving device and electric equipment comprising the same.

Background

The direct current motor has the advantages of small volume, high efficiency, simple structure, convenient speed regulation by changing the armature voltage and the like, and is widely applied to electric equipment such as electric automobiles, electric bicycles, artillery, tanks, radars and the like.

As shown in fig. 8, the conventional dc motor driving device 200 includes a dc motor, a chopper, a dc power supply, and a control unit, wherein the chopper controls the on/off of the power switching tube by using a pulse width modulation technique, and further changes the output voltage and the output current, so that the magnitude of the output current ripple is directly proportional to the magnitude of the output torque and the rotational speed ripple of the dc motor, and is inversely proportional to the switching frequency of the power switching tube. Because the switching loss (or temperature rise and failure rate) of the power switching tube is in direct proportion to the switching frequency of the power switching tube, in order to reduce the ripple size of the output torque and the rotating speed of the direct current motor, the switching frequency of the power switching tube must be increased; when the switching frequency of the power switching tube is increased, the switching loss of the power switching tube is increased, so that the power switching tube is easily damaged, and further, the integral failure or short circuit and other faults of the chopper are caused. This contradictory relationship hinders the development of the dc motor driving apparatus, which makes it difficult to apply the dc motor driving apparatus to the electric equipment having strict requirements on the rotational speed and torque ripple of the motor.

In addition, in the conventional dc motor driving device 200, the maximum output current of the chopper is generally 2 to 3 times of the rated current of the dc motor, and the actual operating current of the chopper used in the high-power dc motor, especially the low-voltage high-current dc motor, often reaches several hundred amperes or even thousands amperes. However, commercially available choppers typically have a maximum output current of less than one thousand amperes and the power switching tubes that can be used in choppers for high power dc motors are expensive, resulting in a chopper with an excessive manufacturing cost.

In addition, in the conventional dc motor driving apparatus 200, the dc motor has only one pair of external connection terminals electrically connected to the power output terminal of the chopper, and thus when the brush or the connection line between the dc motor and the chopper fails, the dc motor is liable to suddenly lose control, which may cause a failure of the electric device or even a safety accident.

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a step-up/step-down chopper type dc motor driving device and an electric apparatus including the step-up/step-down chopper type dc motor driving device.

In order to achieve the purpose, the invention adopts the following technical scheme:

< Structure I >

The invention provides a buck-boost chopper type direct current motor driving device, which is characterized by comprising the following components: a DC motor having a rated voltage; a DC power supply unit having a constant voltage corresponding to a rated voltage; and a buck-boost chopper that converts a constant voltage into a variable voltage based on a control signal and supplies the variable voltage to the dc motor, wherein the buck-boost chopper has m chopper units, each chopper unit includes an upper arm and a lower arm, and a first power output terminal and a second power output terminal, the upper arm and the lower arm are connected in series with each other, the upper arm is connected to a positive electrode of the dc power supply unit, the lower arm is connected to a negative electrode of the dc power supply unit, the upper arm includes at least one power switching tube, at least one inductor, at least one diode, at least one capacitor, and a switching control terminal, the power switching tube is connected in series with the inductor as the upper arm switching tube, the diode is connected in parallel with the capacitor as the upper arm switching tube, the lower arm includes at least one power switching tube as the lower arm switching tube, and the lower arm includes at least one power switching tube, At least one diode as a lower bridge arm diode and a switch control end, the lower bridge arm switch tube and the lower bridge arm diode are connected in reverse parallel, each power switch tube is provided with a control electrode, the switch control end is formed based on the control electrode, the control signal comprises m unit control signals which respectively correspond to the m chopping units and are formed according to a preset phase staggering rule, each unit control signal comprises two switch control signals which correspond to the two switch control ends in the corresponding chopping units, the switch control end in the upper bridge arm is used as the upper bridge arm switch control end, the switch control end in the lower bridge arm is used as the lower bridge arm switch control end for correspondingly receiving the two switch control signals, the first power supply output end is arranged between the upper bridge arm and the lower bridge arm, the second power supply output end is arranged at the end part of the lower bridge arm connected with the direct-current power supply part, the m first power supply output ends of all the chopper units and the m second power supply output ends of all the chopper units respectively form m pairs of power supply output terminals correspondingly, and the direct-current motor comprises: a housing; m pairs of electric brushes fixed in the machine shell; the stator is arranged in the machine shell and comprises m pairs of main magnetic poles corresponding to the m pairs of electric brushes; the rotor is arranged in the stator and comprises a plurality of armature windings which are mutually connected in a preset connection mode, each pair of main magnetic poles comprises an S-polarity main magnetic pole and an N-polarity main magnetic pole which are adjacent, two electric brushes in each pair of electric brushes are adjacent in position, each pair of electric brushes comprises an S-pole corresponding electric brush corresponding to the S-polarity main magnetic pole and an N-pole corresponding electric brush corresponding to the N-polarity main magnetic pole, leading-out ends of all the S-poles corresponding to the electric brushes form m first terminals, and leading-out ends of all the N-poles corresponding to the electric brushes form m second terminals; or all N poles correspond to leading-out ends of the electric brushes to form m first wiring ends, all S poles correspond to leading-out ends of the electric brushes to form m second wiring ends, the m first wiring ends and the m second wiring ends respectively and correspondingly form m pairs of external wiring terminals, the m pairs of external wiring terminals are connected with the m pairs of power output terminals in a one-to-one correspondence mode, and m is a positive integer not less than 2.

The buck-boost chopper type dc motor driving apparatus according to the present invention may further include: the switching frequency fs of the upper bridge arm switching tube in each chopper unit, the inductance value Lr of the inductor and the capacitance value Cr of the capacitor meet the following relations:

the buck-boost chopper type dc motor driving apparatus according to the present invention may further include: the predetermined phase staggering rule is that m phases corresponding to m unit control signals respectively serve as m predetermined phases to stagger m-th of switching periods in sequence, in each chopping unit, a switch control signal corresponding to an upper bridge arm switch control end is set as a reference switch control signal, the phase of the reference switch control signal is determined according to the predetermined phase corresponding to the unit control signal, and a switch control signal corresponding to a lower bridge arm switch control end and the reference switch control signal are set to be opposite to each other; or m is an even number, the predetermined phase shift rule is that m phases corresponding to m unit control signals respectively are sequentially shifted by two m-th of a switching period as m predetermined phases, in each chopper unit, a switching control signal corresponding to an upper arm switching control end is set as a reference switching control signal, the phase of the reference switching control signal is determined according to the predetermined phase corresponding to the unit control signal, and a switching control signal corresponding to a lower arm switching control end and the reference switching control signal are set to be opposite to each other.

The buck-boost chopper type dc motor driving apparatus according to the present invention may further include: and the control part comprises a controller and an amplifier, wherein the controller generates m unit control signals according to a preset phase staggering rule, and the amplifier amplifies two switch control signals in each unit control signal and provides the amplified signals to two switch control ends in the corresponding chopping unit.

The buck-boost chopper type dc motor driving apparatus according to the present invention may further include: the amplifier is composed of m independent amplifying units, the m amplifying units correspond to the m chopping units respectively, each amplifying unit is provided with an amplified signal output part, and the amplified signal output part is composed of two amplified signal output ends.

The buck-boost chopper type dc motor driving apparatus according to the present invention may further include: wherein, the upper bridge arm and the lower bridge arm respectively comprise a power switch tube, and when all the power switch tubes have the same maximum output current I₁The maximum current of the DC motor is I_maxWhen m satisfies the following condition: m is more than 1.1 (I)_max÷I₁) (ii) a Or the upper bridge arm and the lower bridge arm respectively comprise p power switch tubes which are connected in parallel, and when all the power switch tubes have the same maximum output current I₁The maximum current of the DC motor is I_maxM satisfies the following condition: m is more than 1.1 (I)_max÷(k×p×I₁) P is a positive integer not less than 2, k is a parallel coefficient, 1/p<k<1。

The buck-boost chopper type dc motor driving apparatus according to the present invention may further include: wherein the predetermined coupling means is any one of a single stack, a multiple stack and a complex wave.

The buck-boost chopper type dc motor driving apparatus according to the present invention may further include: the power switch tube is a semi-control device or a full-control device, the semi-control device is a common thyristor, and the full-control device is any one of an electric field effect transistor, a gate turn-off thyristor, an integrated gate commutation thyristor, an insulated gate bipolar transistor and an electric power bipolar transistor.

< Structure two >

The present invention also provides an electric apparatus, characterized by comprising: the buck-boost chopper type direct current motor driving device is the buck-boost chopper type direct current motor driving device in the structure I.

The electric device provided by the present invention may further have the following features: wherein, the electrical equipment is any one of electric automobile, electric bicycle, artillery, tank and radar.

Action and Effect of the invention

According to the buck-boost chopper type dc motor driving apparatus and the electric device including the same of the present invention, since the buck-boost chopper has m chopper units each including an upper arm and a lower arm, and a first power output terminal and a second power output terminal, the upper arm and the lower arm being connected in series with each other, the upper arm being connected to the positive electrode of the dc power supply section, the lower arm being connected to the negative electrode of the dc power supply section, the upper arm and the lower arm respectively including at least one power switching tube, a diode connected in reverse parallel with the power switching tube, and a switching control terminal, each power switching tube having a control electrode, the switching control terminal being formed based on the control electrode, the control signal including m unit control signals respectively corresponding to the m chopper units and formed according to a predetermined phase-staggering rule, each unit control signal comprises two switch control signals corresponding to two switch control ends in the corresponding chopping unit, the switch control end in the upper bridge arm is used as an upper bridge arm switch control end, the switch control end in the lower bridge arm is used as a lower bridge arm switch control end and is used for correspondingly receiving the two switch control signals, the first power supply output end is arranged between the upper bridge arm and the lower bridge arm, the second power supply output end is arranged at the end part of the lower bridge arm connected with the direct-current power supply part, m first power supply output ends of all the chopping units and m second power supply output ends of all the chopping units respectively form m pairs of power supply output terminals correspondingly, the leading-out ends of all the S poles corresponding to the electric brushes form m first wiring ends, and the leading-out ends of all the N poles corresponding to the electric brushes form m second wiring ends; or, the leading-out ends of the brushes corresponding to all the N poles form m first wiring terminals, the leading-out ends of the brushes corresponding to all the S poles form m second wiring terminals, the m first wiring terminals and the m second wiring terminals respectively form m pairs of external wiring terminals correspondingly, and the m pairs of external wiring terminals are connected with the m pairs of power output terminals in a one-to-one correspondence manner, so that the invention can realize m pairs of mutually independent brushes on the basis of not changing the rotor structure of the traditional direct current motor, and the armature branch formed by each pair of brushes is independently supplied with power by the corresponding chopping unit, namely, each chopping unit only bears the working current of one armature branch, and the output current of each chopping unit is only one m-th of the rated input current of the direct current motor, so that the buck-boost chopper type chopper can meet the requirement of the high-power direct current motor by using a common power switching tube without adopting a power module or a current-sharing parallel technology, and the manufacturing cost of the buck-boost chopper type chopper is further reduced, and the requirements of a connecting wire and a connecting piece between the buck-boost chopper type chopper and the direct current motor on contact resistance and insulation are reduced, so that the manufacturing cost of the buck-boost chopper type direct current motor driving device is greatly reduced.

In addition, because the upper bridge arm also comprises at least one inductor and at least one capacitor, the upper bridge arm switching tube is connected with the inductor in series, the diode is used as an upper bridge arm diode, the power switching tube is used as an upper bridge arm switching tube, and the capacitor is connected in parallel, the buck-boost chopper can work in a zero-current soft switching state in the switching-on process and the switching-off process by controlling the inductor and the capacitor with low cost, so that the switching loss of the power switching tube is greatly reduced, the heat productivity and the temperature rise of the buck-boost chopper are greatly reduced, the fault rate of the buck-boost chopper is reduced, the service life of the buck-boost chopper is prolonged, and the reliability and the safety of the buck-boost chopper direct-current motor driving device are improved.

In addition, because the control signal comprises m unit control signals which are respectively corresponding to the m chopping units and are formed according to a preset phase staggering rule, each unit control signal comprises two switch control signals which are corresponding to two switch control ends in the corresponding chopping units, and the switch control end in the upper bridge arm and the switch control end in the lower bridge arm of each chopping unit correspondingly receive the two switch control signals, the phases of output current ripples of each chopping unit are different from each other, so that the ripple coefficient after the output current ripples of the m chopping units are superposed is reduced, the ripple coefficient of the output torque and the rotating speed of the direct current motor is further reduced, the electromagnetic interference, vibration and noise of the direct current motor are greatly reduced, and the performance and the service life of the buck-boost chopping type direct current motor driving device are improved.

In addition, because m pairs of electric brushes are mutually independent, and the armature branch formed by each pair of electric brushes is independently supplied with power by the corresponding chopping unit, when a connecting line between one electric brush, the armature branch and the corresponding chopping unit has a fault, the direct current motor only needs to shield the part where the fault is located, and other normal parts can still work, so that the phenomenon of sudden runaway of the traditional direct current motor under the fault condition can be avoided, and the reliability and the safety of the buck-boost chopping direct current motor driving device are improved.

Drawings

Fig. 1 is a schematic circuit connection diagram of a buck-boost chopper dc motor driving apparatus according to an embodiment of the present invention;

fig. 2 is a schematic circuit connection diagram of the buck-boost chopper type dc motor driving apparatus in the state where m is 3 according to the embodiment of the present invention;

fig. 3 is a schematic longitudinal cross-sectional view of a dc motor according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a cross-sectional electrical connection of a DC motor according to an embodiment of the present invention;

fig. 5 is a schematic diagram illustrating the development of a single-lap joint of armature windings of a dc motor according to an embodiment of the present invention;

FIG. 6 is a waveform diagram of a chopper unit in an embodiment of the present invention;

fig. 7 is a waveform comparison diagram of a dc motor according to an embodiment of the present invention and a conventional dc motor;

and

fig. 8 is a schematic circuit connection diagram of a conventional dc motor driving apparatus.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.

< example >

Fig. 1 is a schematic circuit connection diagram of a buck-boost chopper dc motor driving apparatus according to an embodiment of the present invention; fig. 2 is a circuit connection diagram of the buck-boost chopper dc motor driving apparatus in the state where m is 3 according to the embodiment of the present invention.

As shown in fig. 1 and 2, the step-up/step-down chopper dc motor driving apparatus 100 of the present embodiment is provided in an electric device such as an electric automobile, an electric bicycle, a gun, a tank, and a radar, and drives the electric device. The step-up/step-down chopper type dc motor driving apparatus 100 includes a dc motor 10, a step-up/step-down chopper 20, a dc power supply unit 30, a sensor unit 40, and a control unit 50.

Fig. 3 is a schematic longitudinal cross-sectional view of a dc motor according to an embodiment of the present invention; fig. 4 is a schematic diagram of a transverse cross-sectional circuit connection of the dc motor according to the embodiment of the present invention.

As shown in fig. 1 to 4, the dc motor 10 has a rated voltage and a rated current, and includes a housing 11, a stator 12, a brush 13, a rotor 14, and a terminal block (not shown). As shown in fig. 1, the logarithm of the brushes 13 is set to m, which is an integer not less than 2, according to the value of the rated current. As shown in fig. 2 and 4, m is set to 3 in the present embodiment.

As shown in fig. 1 to 4, the stator 12 is disposed in the casing 11 and includes m pairs of main poles 121. In this embodiment, as shown in fig. 4, the stator 12 includes 3 pairs of 6 main poles 121.

Each pair of main poles 121 includes an S-polarity main pole 1211 and an N-polarity main pole 1212. Of all the main poles 121, the polarities of the adjacent two main poles 121 are opposite.

As shown in fig. 1 to 4, m pairs of brushes 13 are fixedly disposed in the casing 11 and respectively correspond to the m pairs of main poles 121. In the present embodiment, as shown in fig. 2 and 4, the number of the brushes 13 is 6 in total for 3 pairs.

Each pair of brushes 13 includes an S-pole corresponding brush 131 corresponding to the S-polarity main pole 1211 and an N-pole corresponding brush 132 corresponding to the N-polarity main pole 1212. The 2 brushes 13 in each pair of brushes 13 are located adjacently; also, each pair of brushes 13 corresponds to a spatial position of each corresponding pair of main magnetic poles 121, so that a maximum torque can be generated.

The brush 13 is any one of a narrow brush and a wide brush, and the brush 13 is a narrow brush in the present embodiment. Each brush 13 comprises one brush body or at least two separately shaped brush bodies arranged axially of the machine and electrically connected in parallel; when the brush 13 includes at least two brush bodies, the actual contact area of each brush with the commutator can be increased, thereby improving the commutation performance of the brush. As shown in fig. 2 to 4, the brush 13 of the present embodiment includes a brush body.

As shown in fig. 1, two terminals of each pair of brushes 13 form a first terminal 1511 and a second terminal 1512, respectively, and m first terminals 1511 and m second terminals 1512 of all brushes 13 form m pairs of external connection terminals 151, respectively, correspondingly.

In this embodiment, as shown in fig. 2 and 4, the first terminal 1511 and the second terminal 1512 form 1-pair external connection terminals 151, the first terminal 1521 and the second terminal 1522 form 1-pair external connection terminals 152, and the first terminal 1531 and the second terminal 1532 form 1-pair wiring terminals 153.

Fig. 5 is a schematic diagram of the development of the armature winding of the dc motor according to the embodiment of the present invention.

As shown in fig. 1 to 4, the rotor 14 is disposed in the stator 12, and includes a plurality of armature windings 141 coupled to each other by a predetermined coupling method, the number of the armature windings 141 is set to 2m × n, and the predetermined coupling method is any one of a single-winding, a multiple-winding, and a complex wave. In this embodiment, as shown in fig. 5, the plurality of armature windings 141 are connected in a single-layer manner, and two adjacent brushes 13 are connected to one armature winding branch, each of which contains n armature windings 141.

A junction box (not shown) is fixed to the cabinet 11, and 3 pairs of external connection terminals 151, 152 and 153 are provided in the junction box as shown in fig. 2 and 4.

As shown in fig. 1, the step-up/step-down chopper 20 converts a constant voltage of the dc power supply unit 30 into a variable voltage whose average voltage is controlled based on a control signal from the control unit 50, and supplies the variable voltage to the dc motor 10. The step-up and step-down chopper 20 includes m chopper units 21 corresponding to the m pairs of brushes 13, respectively. In the present embodiment, as shown in fig. 2, the buck-boost chopper 20 includes 3 chopper units 21.

Each chopper unit 21 includes an upper arm 211 and a lower arm 212 connected in series with each other, and a first power supply output terminal 2211 and a second power supply output terminal 2212.

The upper arm 211 includes a power switch tube 2111, a diode 2112, an inductor 2113, a capacitor 2114 and a switch control terminal 2110. The power switch tube 2111 is connected in series with the inductor 2113, and the diode 2112, the power switch tube 2111, and the capacitor 2114 are connected in parallel with each other. The power transistor 2111 has a control pole which forms the switch control terminal 2110 which is the control terminal of the upper arm switch. In this embodiment, in order to improve the safety of the power switch tube 2111 in actual operation, the switching frequency fs of the power switch tube 2111, the inductance Lr of the inductor 2112, and the capacitance Cr of the capacitor 2114 in each chopper unit 21 satisfy the following relationship:

the lower arm 212 includes a power switch tube 2121, a diode 2122 connected in anti-parallel with the power switch tube 2121, and a switch control terminal 2120. The power switch 2121 has a control pole which forms a switch control terminal 2120 as a lower arm switch control terminal.

When the power switch tubes 2111 of all the upper bridge arms 211 and the power switch tubes 2121 of all the lower bridge arms 212 have the same maximum output current I₁The maximum current of the DC motor 10 is I_maxWhen m satisfies the following condition: m is more than 1.1 (I)_max÷I₁). The maximum output current is an important parameter of the power switch tube, the power switch tube can stably operate only under the current value, and if the working current exceeds the current value, the power switch tube is broken down due to overcurrent, so that the power switch tube is damaged.

In this embodiment, all the power switching transistors are half-control type devices or full-control type devices, the half-control type devices are ordinary thyristors, and the full-control type devices are any one of electric field effect transistors, gate turn-off thyristors, integrated gate commutated thyristors, insulated gate bipolar transistors and electric power bipolar transistors.

As shown in fig. 1, first power supply output terminal 2211 is provided between upper arm 211 and lower arm 212, and second power supply output terminal 2212 is provided at the end of lower arm 211 connected to dc power supply unit 30. The m first power supply outputs 2211 of all the chopper units 21 and the m second power supply outputs 2212 of all the chopper units 21 respectively form m pairs of power supply output terminals 221, and the m pairs of power supply output terminals 221 and the m pairs of external connection terminals 151 are connected in one-to-one correspondence.

In this embodiment, as shown in fig. 2, the first power output 2211 and the second power output 2212 form 1 pair of power output terminals 221, the first power output 2221 and the second power output 2222 form 1 pair of power output terminals 222, the first power output 2231 and the second power output 2232 form 1 pair of power output terminals 223, 3 pairs of power output terminals 221, 222 and 223, and 3 pairs of external connection terminals 151, 152 and 153, which are connected in a one-to-one correspondence.

As shown in fig. 1 and 2, the dc power supply unit 30 has a constant voltage corresponding to the rated voltage of the dc motor 10, and has m pairs of power supply output terminals connected to the m chopper units 21 in one-to-one correspondence. Each pair of power supply output terminals includes a positive electrode 311 and a negative electrode 312, the positive electrode 311 is connected to the upper arm 211 in the corresponding chopper unit 21, and the negative electrode 312 is connected to the lower arm 212 in the corresponding chopper unit 21.

As shown in fig. 1 and 2, the sensor unit 40 detects a physical quantity of the dc motor 10 and outputs a feedback signal to the control unit 50. The sensing unit 40 includes an output sensor 41 and a current sensor 42.

The output sensor 41 detects the displacement, the rotational speed, or the torque output from the dc motor 10 and outputs a corresponding output feedback signal to the control unit 50.

The current sensor 42 detects a line current value of a brush lead-out wire in the dc motor 10 and outputs a corresponding current feedback signal to the control unit 50.

As shown in fig. 1 and 2, the control unit 50 receives an external command signal corresponding to the displacement, the rotational speed, or the torque output from the dc motor 10. The control section 50 includes a controller 51 and an amplifier 52.

The controller 51 generates and outputs a control signal 511 and an enable signal 512 to the amplifier 52 by calculation based on the external command signal and the output feedback signal and the current feedback signal of the sensing part 40. The control signal 511 includes m unit control signals respectively corresponding to the m chopper units 21 and formed in accordance with a predetermined phase shift rule, and each unit control signal includes two switch control signals corresponding to the two switch control terminals 2110, 2120 in the corresponding chopper unit 21. The enable signal 512 is used to control the operating state of the amplifier 52.

The amplifier 52 enters an operating state under the control of the enable signal 512, amplifies the two switch control signals in each unit control signal and provides them to the two switch control terminals 2110, 2120, respectively. The amplifier 52 has m amplified signal output sections corresponding to the m chopper units 21, respectively, and each amplified signal output section is constituted by two amplified signal output terminals 521 and 522. The two amplified signal output terminals 521 and 522 of each amplified signal output part are respectively and correspondingly connected to the two switch control terminals 2110 and 2120 of the corresponding chopper unit 21, specifically: the amplified signal output 521 is connected to the upper arm switch control terminal 2110, and the amplified signal output 522 is connected to the lower arm switch control terminal 2120.

In this embodiment, the predetermined phase shift rule is that m phases corresponding to m unit control signals respectively are sequentially shifted by m times of a switching period as m predetermined phases, in each chopper unit, a switch control signal corresponding to an upper arm switch control end is set as a reference switch control signal, the phase of the reference switch control signal is determined according to the predetermined phase corresponding to the unit control signal, and a switch control signal corresponding to a lower arm switch control end and the reference switch control signal are set to be opposite to each other, so that ripple peak-to-peak values of output currents of power output terminals of the m chopper units after current ripples are superimposed are reduced, thereby reducing ripple peak-to-peak values of output torque and rotation speed, and further improving performance and life of the dc motor. Of course, when m is an even number, the predetermined phase shift rule is that m phases corresponding to m unit control signals respectively are sequentially shifted by two m-th switching cycles as m predetermined phases, so that current ripples of output currents of power supply output terminals of every two chopper units corresponding to every two pairs of brushes which are spatially opposite are the same, a couple moment is generated in the motor, a friction moment between a shaft and a bearing caused by the fact that the couple moment cannot be formed by the output torque ripples of the motor is avoided, abrasion between the shaft and the bearing is reduced, and the performance and the service life of the direct current motor are improved.

Fig. 6 is a waveform diagram of a chopper unit in an embodiment of the present invention.

As shown in fig. 6, a waveform diagram corresponding to Vpwm1 is a voltage waveform diagram of the switching control signal in the embodiment of the present invention shown in fig. 2, a waveform diagram corresponding to I (Lr1) is a current waveform diagram of inductor 2113, a waveform diagram corresponding to V (Cr1) is a voltage waveform diagram of capacitor 2114, a waveform diagram corresponding to I (Q1) is a current waveform diagram of power switch 2111, and a waveform diagram corresponding to I1 is an output current waveform diagram of chopper unit 21. The switching control signal and the switching frequency of the power switch 2111 are both 2 khz for example, and the description will be given below.

Because the current value of the power switch tube 2111 is equal to zero when the waveform of the switching control signal is changed from high level to low level or from low level to high level, that is, the switching loss of the power switch tube 2111 in the conducting process and the switching-off process is equal to zero, the embodiment can realize that the power switch tube works in a zero-current soft switching state in the conducting process and the switching-off process, avoid the problem that the power switch tube in the traditional chopper generates serious switching loss in the conducting process and the switching-off process, greatly reduce the heat productivity and the temperature rise of the buck-boost chopper, further reduce the fault rate of the buck-boost chopper, improve the service life of the buck-boost chopper, and improve the reliability and the safety of the buck-boost chopper direct current motor driving device.

In addition, the current waveform of the inductor 2113 and the voltage waveform of the capacitor 2114 are partially in a resonant state, and when the inductance value of the inductor 2113 is set to Lr and the capacitance value of the capacitor 2114 is set to Cr, the formula is givenThe calculated resonant frequency of the power switch tube 2111 and the calculated resonant frequency of the power switch tube 2111 are both about 2.5 kilohertz and are both greater than 1.1 times of the switching frequency fs of the power switch tube 2111, so that the power switch tube 2111 can be effectively ensured to work in a zero-current soft switching state in the on process and the off process. In the actual operation of the step-up/down chopper, the current waveform of the inductor 2113, the voltage waveform of the capacitor 2114, and the current waveform of the power switching tube 2111 are intermittent, but the output current of the chopper unit 21 is always continuous. The capacitor 2114 may be an electrolytic capacitor. Because the constituent materials of the electrolytic capacitor are common industrial materials, such as aluminum, and the like, and the equipment for manufacturing the electrolytic capacitor is common industrial equipment, the electrolytic capacitor can be produced in a large scale, and the cost of the electrolytic capacitor is relatively low.

Fig. 7 is a waveform comparison diagram of the dc motor according to the embodiment of the present invention and the conventional dc motor.

As shown in fig. 7, Ia1, Ia2, and Ia3 are currents flowing through three brushes a1, a2, and A3 of the dc motor 10 of the present embodiment, respectively; ia10, Tem10, and n10 are the armature current, the electromagnetic torque, and the rotation speed of the dc motor 10 of the present embodiment, respectively, and Ia10 is Ia1+ Ia2+ Ia 3; ia200, Tem200, and n200 are the armature current, electromagnetic torque, and rotational speed, respectively, of a conventional dc motor. The following description will be made by taking, as an example, a state in which the dc motor driving device of the present embodiment and the conventional dc motor driving device are all in the same load, switching frequency, and motor rating parameters. Wherein the switching frequency is 2 khz.

In a steady state, the peak-to-peak value of the ripple is the difference between the maximum value and the minimum value, and the ripple coefficient is the percentage of the peak-to-peak value and the average value.

Since the phases of the three switching control signals are sequentially shifted by 3 switching periods under the predetermined phase shift rule, the currents Ia1, Ia2 and Ia3 of the three brushes a1, a2 and A3 are equal in amplitude and sequentially shifted by 3 switching periods. Although the average values of the armature current Ia10, the electromagnetic torque Tem10 and the rotation speed n10 of the dc motor 10 of the present embodiment are substantially equal to the average values of the armature current Ia200, the electromagnetic torque Tem200 and the rotation speed n200 of the conventional dc motor, respectively, the ripple coefficients of the currents Ia1, Ia2 and Ia3 of the three brushes a1, a2 and A3 of the dc motor 10 of the present embodiment are all about 2 times the ripple coefficient of the armature current Ia200 of the conventional dc motor, however, the ripple coefficients of the armature current Ia10 and the electromagnetic torque Tem10 of the dc motor 10 of the present embodiment are about 18 times the ripple coefficient of the armature current Ia200 and the electromagnetic torque Tem200 of the conventional dc motor, respectively, and the ripple coefficient of the rotation speed n10 of the dc motor 10 of the present embodiment is about 55 times the ripple coefficient of the rotation speed n200 of the conventional dc motor, so that the electromagnetic interference, vibration and noise of the dc motor 10 are greatly reduced, thereby improving the performance and life of the dc motor driving apparatus 100.

Examples effects and effects

According to the buck-boost chopper type dc motor driving apparatus and the electric device including the buck-boost chopper type dc motor driving apparatus of the present embodiment, since the buck-boost chopper has m chopper units, each chopper unit includes an upper arm and a lower arm, and a first power output terminal and a second power output terminal, the upper arm and the lower arm are connected in series with each other, the upper arm is connected to the positive electrode of the dc power supply unit, the lower arm is connected to the negative electrode of the dc power supply unit, the upper arm and the lower arm respectively include a power switching tube, a diode connected in reverse parallel to the power switching tube, and a switching control terminal, each power switching tube has a control electrode, the switching control terminal is formed based on the control electrode, the control signal includes m unit control signals respectively corresponding to the m chopper units and formed according to a predetermined phase-staggering rule, each unit control signal comprises two switch control signals corresponding to two switch control ends in the corresponding chopping unit, the switch control end in the upper bridge arm is used as an upper bridge arm switch control end, the switch control end in the lower bridge arm is used as a lower bridge arm switch control end and is used for correspondingly receiving the two switch control signals, the first power supply output end is arranged between the upper bridge arm and the lower bridge arm, the second power supply output end is arranged at the end part of the lower bridge arm connected with the direct-current power supply part, m first power supply output ends of all the chopping units and m second power supply output ends of all the chopping units respectively form m pairs of power supply output terminals correspondingly, the leading-out ends of all the S poles corresponding to the electric brushes form m first wiring ends, and the leading-out ends of all the N poles corresponding to the electric brushes form m second wiring ends; or, m first terminals are formed at the leading-out ends of the brushes corresponding to all the N poles, m second terminals are formed at the leading-out ends of the brushes corresponding to all the S poles, m pairs of external terminals are formed at the m first terminals and the m second terminals respectively corresponding to the m pairs of external terminals, and the m pairs of external terminals are connected with the m pairs of power output terminals in a one-to-one correspondence manner, so that the embodiment can realize m pairs of mutually independent brushes on the basis of not changing the rotor structure of the traditional direct current motor, and the armature branch formed by each pair of brushes is independently supplied with power by the corresponding chopper unit, that is, each chopper unit only bears the working current of one armature branch, and the output current of each chopper unit is only one m times of the rated input current of the chopper motor, so that the buck-boost chopper can meet the requirement of the high-power direct current motor without adopting a power module or a parallel current-sharing technology and using a common power switching tube, and the manufacturing cost of the buck-boost chopper type chopper is further reduced, and the requirements of a connecting wire and a connecting piece between the buck-boost chopper type chopper and the direct current motor on contact resistance and insulation are reduced, so that the manufacturing cost of the buck-boost chopper type direct current motor driving device is greatly reduced.

In addition, because the upper bridge arm further comprises an inductor and a capacitor, the upper bridge arm switching tube is connected in series with the inductor, the diode is used as the upper bridge arm diode, the power switching tube is used as the upper bridge arm switching tube, and the capacitor is connected in parallel, the buck-boost chopper in the embodiment can realize that the power switching tube works in a zero-current soft switching state in the conducting process and the turning-off process by controlling the inductor and the capacitor with low cost, so that the switching loss of the power switching tube is greatly reduced, the heat productivity and the temperature rise of the buck-boost chopper are greatly reduced, the fault rate of the buck-boost chopper is reduced, the service life of the buck-boost chopper is prolonged, and the reliability and the safety of the buck-boost chopper direct current motor driving device are improved.

In addition, since the control signal includes m unit control signals respectively corresponding to the m chopper units and formed according to a predetermined phase shift rule, each unit control signal includes two switch control signals corresponding to two switch control terminals in the corresponding chopper unit, the switch control terminal in the upper arm and the switch control terminal in the lower arm of each chopper unit correspondingly receive the two switch control signals, therefore, the phases of the output current ripples of each chopper unit in the embodiment are different from each other, so that the ripple factor of the output current ripples of the m chopper units after being superimposed is reduced, and further the ripple factor of the output torque and the rotating speed of the direct current motor is reduced, so that the electromagnetic interference, vibration and noise of the direct current motor are greatly reduced, and the performance and the service life of the buck-boost chopper type direct current motor driving device are improved.

In addition, because m pairs of electric brushes are mutually independent, and the armature branch formed by each pair of electric brushes is independently supplied with power by the corresponding chopping unit, when a connecting line between one electric brush, the armature branch and the corresponding chopping unit has a fault, the direct current motor only needs to shield the part where the fault is located, and other normal parts can still work, so that the phenomenon of sudden runaway of the traditional direct current motor under the fault condition can be avoided, and the reliability and the safety of the buck-boost chopping direct current motor driving device are improved.

The above embodiments are preferred examples of the present invention, and are not intended to limit the scope of the present invention.

For example, in the above embodiment, the number of inductors, diodes, and capacitors in the upper arm is one, and the number of diodes in the lower arm is one. However, in the present invention, the number of the inductor, the number of the diode, and the number of the capacitor in the upper arm, and the number of the diode in the lower arm may be plural, and in this case, when any one of the components fails, the remaining components may also operate normally, which contributes to improvement of reliability and safety of the buck-boost chopper dc motor driving apparatus.

For example, in the embodiment, if the buck-boost chopper type dc motor driving apparatus needs to operate normally, the amplifier needs to be in the operation mode, and therefore, the enable signal may not be applied to the amplifier.

For another example, in the case where the accuracy required for the armature current, the rotation speed, and the torque of the dc motor during steady operation is high, m may also be set according to the peak-to-peak value and the ripple coefficient of the corresponding armature current, rotation speed, and torque ripple.

For example, in the above-described embodiment, the upper arm and the lower arm may be power switching devices, respectively, the power switching device as the upper arm is equivalent to a power switching tube, a diode connected in inverse parallel to the power switching tube, an inductor connected in series with the power switching tube, and a capacitor connected in parallel to the assembly unit including the power switching tube, the inductor, and the diode, and the power switching device as the lower arm is equivalent to a power switching tube and a diode connected in inverse parallel to the power switching tube.