Electric pump and control method
阅读说明：本技术 电动泵以及控制方法 (Electric pump and control method ) 是由 不公告发明人 于 2018-08-24 设计创作，主要内容包括：本发明公开了一种电动泵以及控制方法,包括控制器和三相电机,控制器包括控制电路和微控制单元,控制电路包括电流采集转化电路和电压比较单元,三相电机包括线圈,线圈与控制器电连接,当第一电压信号的电压值大于等于第一参考电压时,微控制单元控制三相电机停止转动,防止电动泵电路板主要元器件及三相电机的线圈损坏。(The invention discloses an electric pump and a control method thereof, the electric pump comprises a controller and a three-phase motor, the controller comprises a control circuit and a micro control unit, the control circuit comprises a current acquisition and conversion circuit and a voltage comparison unit, the three-phase motor comprises a coil, the coil is electrically connected with the controller, when the voltage value of a first voltage signal is more than or equal to a first reference voltage, the micro control unit controls the three-phase motor to stop rotating, and main components of a circuit board of the electric pump and the coil of the three-phase motor are prevented from being damaged.)
1. An electric pump, includes controller and three-phase motor, the three-phase motor includes the coil, the coil with the controller electricity is connected, the controller includes control circuit and little the control unit, its characterized in that: the control circuit comprises a current acquisition and conversion circuit and a voltage comparison unit;
the current acquisition and conversion circuit acquires coil current signals of the three-phase motor and converts the acquired current signals into first voltage signals;
the voltage comparison unit compares the voltage value of the first voltage signal with a preset first reference voltage and outputs a comparison result;
and the micro control unit controls the three-phase motor to run at a rated rotating speed or controls the three-phase motor to stop rotating according to the comparison result output by the voltage comparison unit.
2. The electric pump of claim 1, wherein: when the voltage value of the first voltage signal is greater than or equal to the first reference voltage, the voltage comparison unit outputs a signal which is changed from a high level to a low level;
the micro control unit receives an output signal of the voltage comparison unit, and when the micro control unit receives that the output signal of the voltage comparison unit changes from a high level to a low level, the micro control unit triggers an interrupt program and controls the three-phase motor to stop rotating.
3. The electric pump of claim 2, wherein: when the voltage value of the first voltage signal is smaller than the first reference voltage, the micro control unit collects the voltage value of the first voltage signal or a conversion signal corresponding to the voltage value of the first voltage signal, a second reference voltage is preset in the micro control unit, and when the micro control unit judges that the voltage value of the first voltage signal or the conversion signal corresponding to the voltage value of the first voltage signal is larger than or equal to the second reference voltage, the micro control unit controls the three-phase motor to operate at a reduced rotating speed.
4. The electric pump of claim 3, wherein: the control circuit further comprises a voltage operational amplifier unit, the voltage operational amplifier unit amplifies the amplitude of the first voltage signal, the first voltage signal is changed into the conversion signal through the voltage operational amplifier unit, the micro control unit collects the conversion signal, the micro control unit judges that the voltage value of the conversion signal is larger than or equal to the second reference voltage, and the micro control unit controls the three-phase motor to operate at a reduced rotating speed.
5. The electric pump according to any one of claims 1 to 4, characterized in that: the voltage comparison unit comprises a first operational amplifier, a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor, a first voltage signal is input into the voltage comparison unit from a negative input end of the first operational amplifier, the first resistor, the second resistor, the third resistor and the second capacitor are connected with a positive input end of the first operational amplifier, the other end of the first resistor is connected with a reference voltage, the other end of the second resistor is grounded, the other end of the second capacitor is grounded, the other end of the third resistor is connected with an output end of the first operational amplifier, one end of the first capacitor is connected with a power supply voltage, and the other end of the first capacitor is grounded.
6. The electric pump according to any one of claims 1 to 4, characterized in that: the voltage comparison unit comprises an integrated chip, a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor, a first voltage signal is input into the voltage comparison unit from a second pin of the integrated chip, the third pin of the integrated chip is connected with one ends of the first resistor, the second resistor, the third resistor and the second capacitor, the other end of the first resistor is connected with a reference voltage, the other end of the second resistor is grounded, the other end of the second capacitor is grounded, the other end of the third resistor is connected with the first pin of the integrated chip, one end of the first capacitor is connected with a power supply voltage, the other end of the first capacitor is grounded, an eighth pin of the integrated chip is connected with the power supply voltage, and a fourth pin of the integrated chip is grounded.
7. The electric pump according to claim 5 or 6, characterized in that: the voltage operational amplifier unit comprises a second operational amplifier, a fourth resistor and a fifth resistor, wherein a first voltage signal is input into the voltage operational amplifier unit from the positive input end of the second operational amplifier, one end of the fourth resistor and one end of the fifth resistor are connected with the negative input end of the second operational amplifier, the other end of the fourth resistor is grounded, and the other end of the fifth resistor is connected with the output end of the second operational amplifier.
8. The electric pump according to claim 5 or 6, characterized in that: the voltage operational amplifier unit comprises the integrated chip, a fourth resistor and a fifth resistor, a first voltage signal is input into the voltage operational amplifier unit from a fifth pin of the integrated chip, one end of the fourth resistor and one end of the fifth resistor are connected with a sixth pin of the integrated chip, the other end of the fourth resistor is grounded, and the other end of the fifth resistor is connected with a seventh pin of the integrated chip.
9. A control method capable of controlling the three-phase motor, the control method comprising the steps of:
acquiring a voltage value of a first voltage signal corresponding to a coil current passing through a motor;
and judging whether the voltage value of the first voltage signal is greater than or equal to the first reference voltage, if so, receiving that the output signal of the voltage comparison unit is changed from high level to low level by the micro control unit, triggering an interrupt program by the micro control unit, and controlling the three-phase motor to stop rotating by the micro control unit.
10. The control method according to claim 9, characterized in that: after the micro control unit controls the three-phase motor to stop rotating, the micro control unit continues to collect the first voltage signal and judges whether the voltage value of the first voltage signal is larger than or equal to the first reference voltage, and if not, the micro control unit controls the three-phase motor to operate at a rated rotating speed.
11. The control method according to claim 10, characterized in that: the method further comprises the steps of judging whether the voltage value of the first voltage signal or a conversion signal corresponding to the voltage value of the first voltage signal is greater than or equal to a preset second reference voltage, and if not, controlling the three-phase motor to operate at a rated rotating speed by the micro control unit; if yes, the micro control unit controls the three-phase motor to operate at a set speed lower than the rated rotating speed.
12. The control method according to claim 11, characterized in that: after the micro control unit controls the three-phase motor to operate at a set speed lower than a rated rotating speed, the micro control unit judges whether a voltage value of a first voltage signal or a conversion signal corresponding to the voltage value of the first voltage signal is greater than or equal to a second reference voltage, and if so, the micro control unit controls the three-phase motor to operate at a rotating speed reduced by one gear.
13. The control method according to claim 12, characterized in that: the micro control unit compares the voltage value of the first voltage signal or a conversion signal corresponding to the voltage value of the first voltage signal with the second reference voltage; when the voltage value of the first voltage signal or the conversion signal corresponding to the voltage value of the first voltage signal is smaller than the second reference voltage, the micro control unit controls the three-phase motor to stop decelerating, and the micro control unit controls the three-phase motor to operate at the current rotating speed.
Technical Field
The invention relates to the technical field of motor control, in particular to an electric pump and a control method.
Background
With the improvement of control accuracy, the electric pump is widely applied to various industries, and when the electric pump is overloaded or in an abnormal working state such as locked rotor, the coil current of the three-phase motor passing through the electric pump is too large, which may cause damage to main devices of a circuit board of the electric pump and a coil of the motor. There is therefore a need for an improved electric pump to solve the above technical problems.
Disclosure of Invention
The invention aims to provide an electric pump and a control method, which can protect main components of a circuit board of the electric pump and a coil of a motor.
In order to achieve the purpose, the invention adopts the following technical scheme:
an electric pump, includes controller and three-phase motor, the three-phase motor includes the coil, the coil with the controller electricity is connected, the controller includes control circuit and little the control unit, its characterized in that: the control circuit comprises a current acquisition and conversion circuit and a voltage comparison unit;
the current acquisition and conversion circuit acquires coil current signals of the three-phase motor and converts the acquired current signals into first voltage signals;
the voltage comparison unit compares the voltage value of the first voltage signal with a preset first reference voltage and outputs a comparison result;
and the micro control unit controls the three-phase motor to run at a rated rotating speed or controls the three-phase motor to stop rotating according to the comparison result output by the voltage comparison unit.
The invention also discloses a control method,
a control method capable of controlling the three-phase motor, the control method comprising the steps of:
acquiring a voltage value of a first voltage signal corresponding to a coil current passing through a motor;
and judging whether the voltage value of the first voltage signal is greater than or equal to the first reference voltage, if so, receiving that the output signal of the voltage comparison unit is changed from high level to low level by the micro control unit, triggering an interrupt program by the micro control unit, and controlling the three-phase motor to stop rotating by the micro control unit.
The technical scheme of the invention provides an electric pump and a control method, the electric pump comprises a current acquisition and conversion circuit, a voltage comparison unit and a micro control unit, wherein the current acquisition and conversion circuit acquires a coil current signal of a three-phase motor and converts the acquired current signal into a first voltage signal, the voltage comparison unit compares the first voltage signal with a preset first reference voltage, the micro control unit receives an output signal of the voltage comparison unit, and the micro control unit controls the three-phase motor to operate at a rated rotating speed or controls the three-phase motor to stop rotating according to a comparison result output by the voltage comparison unit; the value of the collected current signal of the motor coil is large, the current can possibly damage main devices of the circuit board and the motor coil, the current value of the coil can be reduced by controlling the motor to stop rotating, and the main devices of the circuit board and the coil of the motor are protected.
Drawings
FIG. 1 is a block diagram of the connection of a controller to a first embodiment of a motor in an electric pump;
FIG. 2 is a block diagram of the connection of the controller with the first control circuit of FIG. 1 to the motor;
FIG. 3 is a block diagram of the connection of the controller with the second control circuit of FIG. 1 to the motor;
FIG. 4 is a block diagram of the connection of a controller to a second embodiment of a motor in an electric pump;
FIG. 5 is a block diagram of the connection of the controller with the control circuit of FIG. 4 to the motor;
FIG. 6 is a block diagram of the connection of a controller to a third embodiment of a motor in an electric pump;
FIG. 7 is a block diagram of the connection of the controller with the first control circuit of FIG. 6 to the motor;
FIG. 8 is a block diagram of the connection of the controller with the second control circuit of FIG. 6 to the motor;
FIG. 9 is a control flow chart of the first embodiment of the control method;
fig. 10 is a control flow chart of the second embodiment of the control method;
fig. 11 is a control flowchart of the third embodiment of the control method.
Detailed Description
The invention will be further described with reference to the following figures and specific examples:
as shown in fig. 1 and 2, the electric pump includes a controller and a three-phase motor, the controller includes a control circuit and a micro control unit, the control circuit includes a current collecting and converting circuit and a voltage comparing unit, the three-phase motor includes a coil, and the coil is electrically connected to the controller.
The current acquisition and conversion circuit acquires coil current signals of the three-phase motor and converts the acquired current signals into first voltage signals; specifically, the current acquisition and conversion circuit acquires the coil current signal of the electric pump three-phase motor through the sampling resistor R and converts the acquired coil current signal into a voltage signal. The low-frequency filter circuit comprises a resistor R29 and a capacitor C12, one end of the resistor R29 is connected with the sampling resistor R, the other end of the resistor R29 is connected with the capacitor C12, and the other end of the capacitor C12 is grounded.
The voltage comparison unit compares the voltage value of the first voltage signal with a preset first reference voltage mu 1 and outputs a comparison result;
in one embodiment, the voltage comparison unit includes a first operational amplifier U3A, a first resistor R36, a second resistor R37, a third resistor R38, a first capacitor C16 and a second capacitor C26, a first voltage signal is input to the voltage comparison unit from a negative input terminal of the first operational amplifier U3A, one end of the first resistor R36, one end of the second resistor R37, one end of the third resistor R38 and one end of the second capacitor C26 are connected to a positive input terminal of the first operational amplifier U3A, the other end of the first resistor R36 is connected to a reference voltage Ej, the other end of the second resistor R37 is grounded, the other end of the second capacitor C26 is grounded, the other end of the third resistor R38 is connected to an output terminal of the first operational amplifier U3A, one end of the first capacitor C16 is connected to a supply voltage Ei, and the other end of the first capacitor C16 is grounded.
In another embodiment, the first op-amp U3A in the voltage comparing unit may also be an integrated chip U3, as shown in fig. 3, the voltage comparing unit includes an integrated chip U3, a first resistor R36, a second resistor R37, a third resistor R38, a first capacitor C16 and a second capacitor C26, the first voltage signal is input to the voltage comparing unit from the second pin of the integrated chip U3, the third pin of the integrated chip U3 is connected to one end of the first resistor R36, the second resistor R37, the third resistor R38 and the second capacitor C26, the other end of the first resistor R36 is connected to a reference voltage Ej, the other end of the second resistor R37 is grounded, the other end of the second capacitor C26 is grounded, the other end of the third resistor R38 is connected to the first pin of the integrated chip U3, one end of the first capacitor C16 is connected to a supply voltage Ei, the other end of the first capacitor C16 is grounded, the eighth pin of the integrated chip U3 is connected to the supply voltage Ei, and the fourth pin of the integrated chip U3 is grounded.
In the voltage comparison unit, the voltage value of the first reference voltage μ 1 can be changed by changing the resistances of the first resistor R36, the second resistor R37, and the third resistor R38, specifically, μ 1 ═ R37/(R36 · R38) (Ej · R38+ Ei · R36), where the third resistor R38 serves as a positive feedback resistor, which functions to slow down frequent jumps of the output signal and ensure the stability of the output signal of the first operational amplifier U3A.
And the micro control unit controls the three-phase motor to run at a rated rotating speed or controls the three-phase motor to stop rotating according to the comparison result output by the voltage comparison unit.
When the voltage value of the first voltage signal is greater than the preset first reference voltage μ 1, that is, the value of the collected current signal of the motor coil is greater, the current may damage the main device of the circuit board and the coil of the motor, and the current value of the coil is reduced by controlling the motor to stop rotating, so that the main device of the circuit board and the coil of the motor are protected.
Specifically, the pin input end of the GPIO of the micro control unit is connected with the output end of the voltage comparison unit and used for receiving an output signal of the voltage comparison unit, when the micro control unit receives a jump of the output signal of the voltage comparison unit changing from a high level to a low level, the micro control unit triggers an interrupt, executes an interrupt program and controls the three-phase motor to stop rotating.
As shown in fig. 4 and 5, the second embodiment of the present invention is mainly different from the first embodiment in that: the first voltage signal is also input into the micro control unit through AN AN pin of the micro control unit, when the voltage value of the first voltage signal is smaller than a first reference voltage mu 1, the micro control unit collects the first voltage signal, judges that when the voltage value of the first voltage signal is larger than or equal to a preset second
In this embodiment, the electric pump includes two overcurrent protection modes, specifically, the current collecting and converting circuit obtains a voltage value of a first voltage signal corresponding to a coil current passing through the motor, and transmits the voltage value to the voltage comparing unit and the micro control unit, when the voltage value of the first voltage signal is greater than or equal to a first reference voltage μ 1, an output signal of the voltage comparing unit changes from a high level to a low level, and the micro control unit receives a jump of the output signal of the voltage comparing unit changing from the high level to the low level, and triggers an interrupt program to control the three-phase motor to stop rotating; and if the voltage value of the first voltage signal is less than the first reference voltage mu 1, the micro control unit judges whether the voltage value of the first voltage signal is greater than or equal to the second
As shown in fig. 6 to 8, the third embodiment of the present invention is mainly different from the second embodiment in that: the control circuit further comprises a voltage operational amplifier unit, the voltage operational amplifier unit amplifies the amplitude of a first voltage signal, the first voltage signal is converted into a conversion signal through the voltage operational amplifier unit, the conversion signal is input into the micro control unit through AN AN pin of the micro control unit, the micro control unit collects the conversion signal corresponding to the voltage value of the first voltage signal and compares the conversion signal with a preset second
In this embodiment, the purpose of the voltage op-amp unit is to amplify the first voltage signal to a desired amplitude value and to the same order of magnitude as the second
In one embodiment, the voltage operational amplifier unit includes a second operational amplifier U3B, a fourth resistor R13, and a fifth resistor R14, the first voltage signal is input to the voltage operational amplifier unit from the positive input terminal of the second operational amplifier U3B, one end of the fourth resistor R13 and one end of the fifth resistor R14 are connected to the negative input terminal of the second operational amplifier U3B, the other end of the fourth resistor R13 is grounded, and the other end of the fifth resistor R14 is connected to the output terminal of the second operational amplifier U3B.
In another embodiment, the second operational amplifier U3B in the voltage operational amplifier unit may be an integrated chip U3, as shown in fig. 8, the voltage operational amplifier unit includes an integrated chip U3, a fourth resistor R13, and a fifth resistor R14, the first voltage signal is input into the voltage operational amplifier unit from a fifth pin of the integrated chip U3, one end of the fourth resistor R13 and one end of the fifth resistor R14 are connected to a sixth pin of the integrated chip U3, the other end of the fourth resistor R13 is grounded, and the other end of the fifth resistor R14 is connected to a seventh pin of the integrated chip U3.
The integrated chip U3 is used for replacing a first operational amplifier U3A in the voltage comparison unit and a second operational amplifier U3B in the voltage operational amplifier unit, so that the composition of electronic components can be reduced, and the circuit can be built more conveniently.
In the voltage operational amplifier unit, the fourth resistor R13 and the fifth resistor R14 form a voltage series negative feedback branch, and form an in-phase proportional operational amplifier circuit with the second operational amplifier U3B, and the amplification factor θ can be changed by adjusting the resistance values of the fourth resistor R13 and the fifth resistor R14, where θ is (R13+ R14)/R13 in this embodiment.
In this embodiment, the voltage value of the first voltage signal is further shaped before being input to the micro control unit by a corresponding converted signal amplified by the voltage operational amplifier unit, the shaping circuit includes a resistor R15 and a capacitor C11, one end of the resistor R15 is connected to the output end of the voltage operational amplifier unit, the other end of the resistor R15 is connected to one end of the capacitor C11, the other end of the capacitor C11 is grounded, and the shaping circuit is used for shaping and filtering the amplified first voltage signal to eliminate noise interference coupled in the signal.
The present invention also discloses a control method, which can control a three-phase motor, as shown in fig. 9, which is a control flowchart of the first embodiment, and the control method includes the following steps:
acquiring a voltage value of a first voltage signal corresponding to a coil current passing through a motor;
judging whether the voltage value of the first voltage signal is greater than or equal to a first reference voltage mu 1, if so, outputting a signal from high voltage to low voltage by the voltage comparison unit, receiving the signal from the voltage comparison unit and changing the output signal from high level to low level by the micro control unit, triggering an interrupt program by the micro control unit, and controlling the three-phase motor to stop rotating by the micro control unit;
after the micro control unit controls the three-phase motor to stop rotating, the micro control unit continues to acquire the first voltage signal and judges whether the voltage value of the first voltage signal is greater than or equal to a first reference voltage mu 1, and if not, the micro control unit controls the three-phase motor to operate at a rated rotating speed.
In a second embodiment, the control method further includes determining whether the voltage value of the first voltage signal is greater than or equal to a preset second reference voltage, as shown in fig. 10, when the voltage value of the first voltage signal is less than a first reference voltage μ 1, the micro control unit determines whether the voltage value of the first voltage signal is greater than or equal to a second
after the micro control unit controls the three-phase motor to run at a set speed lower than the rated rotating speed, the micro control unit judges whether the voltage value of the first voltage signal is greater than or equal to a second
and the micro control unit compares the voltage value of the first voltage signal with the second
In a third embodiment, the control circuit further includes a voltage operational amplifier unit, the voltage operational amplifier unit amplifies an amplitude of the first voltage signal, the first voltage signal is converted into a corresponding converted signal after being amplified by the voltage operational amplifier unit, and the converted signal is compared with a second
after the micro control unit controls the three-phase motor to operate at a set speed lower than the rated rotating speed, the micro control unit judges whether the voltage value of the converted signal is greater than or equal to a second
and the micro control unit compares the voltage value of the conversion signal with the second
It should be noted that: although the present invention has been described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that the present invention may be modified and equivalents may be substituted for those skilled in the art, and all technical solutions and modifications that do not depart from the spirit and scope of the present invention should be covered by the claims of the present invention.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：护栏、隔离墙与光子能结合的发电系统