Brushless motor control system with power supply protection

Abstract

The utility model discloses a brushless motor control system with power supply protection. The brushless motor control system comprises a main control unit, an EMC rectification filtering unit, a voltage conversion unit, a protection unit, a motor driving unit and a brushless motor. The protection unit comprises a first diode, a resistor module and a charging capacitor. The protection unit is arranged between the EMC rectifying and filtering unit and the voltage conversion unit, when the voltage output by the EMC rectifying and filtering unit is lower than the set voltage, the charging capacitor only charges and does not discharge by utilizing the one-way conduction characteristic of the first diode, and the voltage output by alternating current rectification is smoother after passing through the protection unit; normal use of the main control unit and some electronic components is prevented from being affected, and power supply is more stable.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor control technical field, concretely relates to a brushless motor control system with power protection. BACKGROUND

[0002] The prior art in the power supply control of brushless motor, generally, the alternating current is rectified to high voltage direct current through the rectifier bridge, and then the high voltage direct current is stepped down to low voltage direct current through the direct current conversion unit, and the load, main control unit, motor drive unit and other components are powered. But in the process of use, because the voltage and current of alternating current change with time according to sine (cosine) function law, the voltage of alternating current rectification output is not smooth enough, when the output voltage is lower than the set voltage, the direct current conversion unit can not normally output, at the same time, it will affect the normal use of load, main control unit, motor drive unit and other electronic components, and seriously, it can cause damage to brushless motor.

[0003] In summary, at present, there is an urgent need for a brushless motor control system with power protection that can make power supply more stable. UTILITY MODEL CONTENTS

[0004] The utility model discloses a kind of brushless motor control systems with power protection to solve the technical deficiency of the above-mentioned.

[0005] The utility model discloses a kind of brushless motor control systems with power protection, including main control unit, EMC rectification filter unit, voltage conversion unit, protection unit, motor drive unit, brushless motor;

[0006] The output end of the EMC rectification filter unit is equipped with electrolytic capacitor between ground end, the output end of the EMC rectification filter unit is equipped with protection unit between the input end of voltage conversion unit, the output end of the voltage conversion unit is electrically connected with main control unit, motor drive unit respectively, the motor drive unit is electrically connected with main control unit, the output end of EMC rectification filter unit and brushless motor respectively;

[0007] The protection unit includes first diode, resistance module, charging capacitor, the anode of the first diode is electrically connected with the output end of EMC rectification filter unit, the cathode of the first diode is sequentially connected with resistance module, charging capacitor and then electrically connected with ground end, the input end of the voltage conversion unit is electrically connected with the common connection point of resistance module, charging capacitor.

[0008] Further, the resistance module includes first resistance, second resistance and third resistance that are sequentially connected, the first resistance is electrically connected with the cathode of the first diode, the third resistance is electrically connected with the common connection point of charging capacitor, voltage conversion unit.

[0009] Further, a start-stop unit is further included, which is electrically connected with the main control unit and the output end of the voltage conversion unit respectively.

[0010] Further, a brake unit is further included, which comprises a brake control module and a discharge resistor, the control end of the brake control module is electrically connected with the main control unit, the brake control module is electrically connected with the output end of the EMC rectification filter unit and the output end of the voltage conversion unit respectively, and the brake control module is connected with the discharge resistor in series.

[0011] Further, the brake control module comprises a driving module, a third triode, a third diode, a ninth resistor, a tenth resistor, an eleventh resistor and a first capacitor, one end of the ninth resistor is electrically connected with the main control unit, the other end of the ninth resistor and the output end of the voltage conversion unit are electrically connected with the driving module respectively, the first capacitor is connected between the driving module and the ground in series, the first end of the tenth resistor is electrically connected with the driving module, the second end of the tenth resistor is electrically connected with the ground through the eleventh resistor, the second end of the tenth resistor is electrically connected with the gate of the third triode, the source of the third triode is electrically connected with the ground, the drain of the third triode is electrically connected with the output end of the EMC rectification filter unit through the third diode, and the two ends of the third diode are electrically connected with the discharge resistor through the connector.

[0012] Further, an anti-shock unit is further included, which is electrically connected with the main control unit, the EMC rectification filter unit and the output end of the voltage conversion unit respectively, the anti-shock unit comprises a first relay, a first triode, a second triode, a second diode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor.

[0013] The first end of the fourth resistor is electrically connected with the moving contact of the first relay, the second end of the fourth resistor is electrically connected with the static contact of the first relay, the two ends of the fourth resistor are electrically connected with the EMC rectification filter unit respectively, the first end of the coil of the first relay is connected with the ground in sequence after being connected with the seventh resistor and the second diode in series, the second end of the coil of the first relay is electrically connected with the ground, the base of the first triode is electrically connected with the collector of the second triode through the sixth resistor, the fifth resistor is connected between the base and the emitter of the first triode in series, the emitter of the first triode is electrically connected with the output end of the voltage conversion unit, the collector of the first triode is electrically connected with the negative electrode of the second diode, the emitter of the second triode is electrically connected with the ground, and the base of the second triode is electrically connected with the main control unit through the eighth resistor.

[0014] Further, a temperature acquisition unit is further included, which is electrically connected with the main control unit and the output end of the voltage conversion unit respectively, and is used for acquiring the temperature information of the power device in the motor driving unit.

[0015] The utility model discloses a brushless motor control system with power protection, through setting protection unit between EMC rectification filter unit and voltage conversion unit, when the voltage that EMC rectification filter unit exports is lower than setting voltage, utilize the unidirectional conduction characteristic of first diode, make charging capacitor only charge and do not carry out discharge, and the voltage of alternating -current rectification output is more smooth after protection unit, avoid the normal use of main control unit and some electronic components, make power supply more stable. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the structural principle diagram of a brushless motor control system with power protection of the present disclosure;

[0017] Figure 2 It is the circuit principle diagram of EMC rectification filter unit, voltage conversion unit, protection unit and anti -impact unit;

[0018] Figure 3 It is the circuit principle diagram of brake control module;

[0019] Figure 4 It is the circuit principle diagram of main control unit;

[0020] Figure 5 It is the circuit principle diagram of start -stop unit, temperature acquisition unit, work instruction unit, input voltage detection unit, high voltage DC detection unit and counter electromotive force detection unit;

[0021] Figure 6 It is the circuit principle diagram of motor drive unit.

[0022] In the drawing: 1, main control unit;2, EMC rectification filter unit;3, voltage conversion unit;4, protection unit;5, motor drive unit;6, brushless motor;7, brake unit, 8, brake control module, 9, unloading resistance, 10, anti -impact unit, 11, start -stop unit, 12, temperature acquisition unit, 13, input voltage detection unit, 14, high voltage DC detection unit, 15, counter electromotive force detection unit, 16, work instruction unit. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the utility model will be described clearly and completely below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art belong to the scope of protection of the utility model.

[0024] Embodiment 1:

[0025] AsFigures 1-6 As shown in the figure, the brushless motor control system with power protection described in the embodiment comprises a main control unit 1, an EMC rectification filter unit 2, a voltage conversion unit 3, a protection unit 4, a motor drive unit 5, and a brushless motor 6.

[0026] An electrolytic capacitor C4 is arranged between the output end of the EMC rectification filter unit 2 and the ground end, and the protection unit 4 is arranged between the output end of the EMC rectification filter unit 2 and the input end of the voltage conversion unit 3. The output end of the voltage conversion unit 3 is electrically connected to the main control unit 1 and the motor drive unit 5 respectively, and the motor drive unit 5 is electrically connected to the output end of the EMC rectification filter unit 2 and the brushless motor 6 respectively.

[0027] As shown in the figure, Figure 2 The protection unit 4 comprises a first diode D2, a resistance module, and a charging capacitor C60. The positive electrode of the first diode D2 is electrically connected to the output end of the EMC rectification filter unit 2, the negative electrode of the first diode D2 is electrically connected to the ground end in sequence through the resistance module and the charging capacitor C60, and the input end of the voltage conversion unit 3 is electrically connected to the common connection point of the resistance module and the charging capacitor C60. The protection unit 4 can maintain the normal output of the chip U1 for a short time, so that the main control unit 1 and the motor control unit in the motor drive unit 5 can work normally.

[0028] The resistance module comprises a first resistor R56, a second resistor R51, and a third resistor R49 connected in sequence. The first resistor R56 is electrically connected to the negative electrode of the first diode D2, and the third resistor R49 is electrically connected to the common connection point of the charging capacitor C60 and the voltage conversion unit 3.

[0029] As shown in the figure, Figure 5 Preferably, a start-stop unit 11 electrically connected to the output end of the main control unit 1 and the voltage conversion unit 3 is further included.

[0030] As shown in the figure, Figure 1 , 3 Preferably, a brake unit 7 is further included. The brake unit 7 comprises a brake control module 8 and a discharge resistor 9. The control end of the brake control module 8 is electrically connected to the main control unit 1, the brake control module 8 is electrically connected to the output end of the EMC rectification filter unit 2 and the output end of the voltage conversion unit 3 respectively, and the brake control module 8 is connected in sequence with the discharge resistor 9.

[0031] The brake control module 8 comprises a driving module U8, a third triode Q11, a third diode D19, a ninth resistor R48, a tenth resistor R52, an eleventh resistor R53, a first capacitor C59, one end of the ninth resistor R48 is electrically connected with the master control unit 1, the other end of the ninth resistor R48 and the output end of the voltage conversion unit 3 are electrically connected with the driving module U8 respectively, the first capacitor C59 is connected in series between the driving module U8 and the ground, the first end of the tenth resistor R52 is electrically connected with the driving module U8, the second end of the tenth resistor R52 is electrically connected with the ground through the eleventh resistor R53, the second end of the tenth resistor R52 is electrically connected with the gate of the third triode Q11, the source of the third triode Q11 is electrically connected with the ground, the drain of the third triode Q11 is electrically connected with the output end of the EMC rectifier filter unit 2 through the third diode D19, and the two ends of the third diode D19 are electrically connected with the discharge resistor 9 through the connector CN3.

[0032] When the start-stop unit 11 is disconnected, the PWM output is stopped, and the three power lines of the brushless motor 6 are short-circuited, because the motor winding is inductive, once short-circuited, equivalent to a boost inductance, the voltage will be superimposed on the capacitor, the master control unit 1 detects the speed of the brushless motor 6, when the speed does not reach the set threshold, the brake unit 7 is in a non-working state, at this time, the energy does not need to be discharged, when the speed reaches the set threshold, the master control unit 1 sends a brake signal to the brake unit 7, so that the driving module U8 sends a signal to the third triode Q11 to make it conductive, and the energy generated when the brake brushless motor 6 is discharged through the discharge resistor 9.

[0033] As shown in Figure 2 Preferably, the anti-shock unit 10 electrically connected with the master control unit 1, the EMC rectifier filter unit 2 and the output end of the voltage conversion unit 3 respectively is further included, the anti-shock unit 10 comprises a first relay J1, a first triode Q8, a second triode Q9, a second diode D18, a fourth resistor RX1, a fifth resistor R72, a sixth resistor R73, a seventh resistor R74 and an eighth resistor R76.

[0034] The first end of the fourth resistor RX1 is electrically connected with the moving contact of the first relay J1, the second end of the fourth resistor RX1 is electrically connected with the static contact of the first relay J1, the two ends of the fourth resistor RX1 are respectively electrically connected with the EMC rectification filter unit 2, the first end of the coil of the first relay J1 is electrically connected with the ground through the seventh resistor R74 and the second diode D18 in sequence, the second end of the coil of the first relay J1 is electrically connected with the ground, the base of the first triode Q8 is electrically connected with the collector of the second triode Q9 through the sixth resistor R73, the fifth resistor R72 is connected in series between the base and the emitter of the first triode Q8, the emitter of the first triode Q8 is electrically connected with the output of the voltage conversion unit 3, the collector of the first triode Q8 is electrically connected with the negative electrode of the second diode D18, the emitter of the second triode Q9 is electrically connected with the ground, and the base of the second triode Q9 is electrically connected with the main control unit 1 through the eighth resistor R76. The fourth resistor RX1 and the first relay J1 form a capacitor buffer circuit. After the power-on moment, there is no electricity in the electrolytic capacitor C4 in the latter stage, which is equivalent to a short circuit for the circuit, thereby avoiding the impact current during power-on from causing the circuit overload, and the charging current of the electrolytic capacitor C4 is limited, thereby playing a role in protecting the power supply circuit.

[0035] Preferably, as shown in Figure 5 The temperature acquisition unit 12 is electrically connected with the output of the main control unit 1 and the voltage conversion unit 3, and the temperature acquisition unit 12 comprises a thermistor RT1 electrically connected through a connector CN2, which is used to acquire the temperature information of the power device (for example, Q1) in the motor driving unit 4. When the temperature of the power device reaches a high temperature setting value or a setting threshold value, the main control unit 1 controls the brushless motor 6 to reduce the output power or stop working, and simultaneously alarms through the working indication unit 16 to inform the user of the fault content.

[0036] Preferably, the system further comprises an input voltage detection unit 13, a high-voltage direct-current detection unit 14, a back electromotive force detection unit 15 and a working indication unit 16.

[0037] The input voltage detection unit 13 is used to detect whether the 220V alternating current has a normal input. If the input is normal, the system normally works. If the input is not detected, the main control unit 1 does not start the system.

[0038] The high-voltage direct-current detection unit 14 is used to detect whether the EMC rectification filter unit 2 outputs a set voltage. If the main control unit 1 judges that the voltage is lower than the set voltage, the main control unit 1 controls the working indication unit 16 connected therewith to flash, and the motor driving unit in the motor driving unit 5 does not work. When the voltage is higher than the set voltage, the main control unit 1 does not start the system.

[0039] The back electromotive force detection unit 15 collects the back electromotive forces of the U, V, W three-phase lines of the brushless motor 6, and the rotor position can be determined by detecting the time sequence of the three-phase back electromotive forces, so as to accurately control the working state of the brushless motor 6.

[0040] The utility model is not limited to the above-mentioned best implementation, and anyone can draw other various forms of products under the enlightenment of the utility model, but no matter make any change in its shape or structure, any technical scheme with the same or similar to the application falls within the protection scope of the utility model.

Claims

1. A brushless motor control system with power supply protection, characterized by: The application relates to a brushless motor drive circuit, which comprises a main control unit (1), an EMC rectification filter unit (2), a voltage conversion unit (3), a protection unit (4), a motor drive unit (5) and a brushless motor (6). An electrolytic capacitor is arranged between the output end of the EMC rectification filter unit (2) and a grounding end, a protection unit (4) is arranged between the output end of the EMC rectification filter unit (2) and the input end of the voltage conversion unit (3), the output end of the voltage conversion unit (3) is electrically connected with the main control unit (1) and the motor drive unit (5) respectively, and the motor drive unit (5) is electrically connected with the main control unit (1), the output end of the EMC rectification filter unit (2) and the brushless motor (6) respectively. The protection unit (4) comprises a first diode, a resistance module and a charging capacitor, the positive pole of the first diode is electrically connected with the output end of the EMC rectification filter unit (2), the negative pole of the first diode is sequentially connected with the resistance module and the charging capacitor and then is electrically connected with the grounding end, and the input end of the voltage conversion unit (3) is electrically connected with the common connection point of the resistance module and the charging capacitor.

2. The brushless motor control system with power supply protection of claim 1, wherein: The resistance module comprises a first resistance, a second resistance and a third resistance which are sequentially connected, the first resistance is electrically connected with the negative pole of the first diode, and the third resistance is electrically connected with the common connection point of the charging capacitor and the voltage conversion unit (3).

3. The brushless motor control system with power supply protection of claim 1, wherein: The application further comprises a start-stop unit (11) which is electrically connected with the main control unit (1) and the output end of the voltage conversion unit (3) respectively.

4. The brushless motor control system with power supply protection of claim 3, wherein: The application further comprises a brake unit (7), the brake unit (7) comprises a brake control module (8) and a discharge resistance (9), the control end of the brake control module (8) is electrically connected with the main control unit (1), the brake control module (8) is electrically connected with the output end of the EMC rectification filter unit (2) and the output end of the voltage conversion unit (3) respectively, and the brake control module (8) is connected with the discharge resistance (9) in series.

5. The brushless motor control system with power supply protection of claim 4, wherein: The brake control module (8) comprises a driving module, a third triode, a third diode, a ninth resistance, a tenth resistance, an eleventh resistance and a first capacitor, one end of the ninth resistance is electrically connected with the main control unit (1), the other end of the ninth resistance and the output end of the voltage conversion unit (3) are electrically connected with the driving module respectively, the first capacitor is connected between the driving module and the grounding end in series, the first end of the tenth resistance is electrically connected with the driving module, the second end of the tenth resistance is electrically connected with the grounding end through the eleventh resistance, the second end of the tenth resistance is electrically connected with the gate of the third triode, the source of the third triode is electrically connected with the grounding end, the drain of the third triode is electrically connected with the output end of the EMC rectification filter unit (2) through the third diode, and the two ends of the third diode are electrically connected with the discharge resistance (9) through a connector.

6. A brushless motor control system with power supply protection as claimed in any one of claims 1 to 5 wherein: The application further comprises an anti-impact unit (10) which is electrically connected with the main control unit (1), the EMC rectification filter unit (2) and the output end of the voltage conversion unit (3) respectively, the anti-impact unit (10) comprises a first relay, a first triode, a second triode, a second diode, a fourth resistance, a fifth resistance, a sixth resistance and a seventh resistance. The first end of the fourth resistor is electrically connected with the moving contact of the first relay, the second end of the fourth resistor is electrically connected with the static contact of the first relay, the two ends of the fourth resistor are respectively electrically connected with the EMC rectifier filter unit (2), the first end of the first relay coil is electrically connected with the ground end after being connected with the seventh resistor and the second diode in sequence, the second end of the first relay coil is electrically connected with the ground end, the base of the first triode is electrically connected with the collector of the second triode through the sixth resistor, the fifth resistor is connected between the base and the emitter of the first triode, the emitter of the first triode is electrically connected with the output end of the voltage conversion unit (3), the collector of the first triode is electrically connected with the negative electrode of the second diode, the emitter of the second triode is electrically connected with the ground end, and the base of the second triode is electrically connected with the main control unit (1) through the eighth resistor.

7. A brushless motor control system with power supply protection as claimed in any one of claims 1 to 5 wherein: The temperature acquisition unit (12) electrically connected with the main control unit (1) and the output end of the voltage conversion unit (3) respectively is further included, which is used for acquiring temperature information of power devices in the motor driving unit (4).

Images